JPH0367914B2 - - 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] The air cleaner of a motorcycle is 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. , which has a negative effect on the filling efficiency of this 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 cleaner was placed immediately after the head pipe located at the front end of the frame, as seen in ``Japanese Patent Application Laid-Open No. 181969/1980,'' and fresh air was placed in front of the air cleaner. A motorcycle is known in which an intake duct is provided for introducing the air, and the inlet end of the intake duct is opened immediately after the head pipe.

[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 wind from the front is transmitted between the head pipe and the inlet end of the intake duct. This causes the wind to flow into the intake duct through a narrow space, resulting in extremely large inflow resistance.

As a result, the amount of air introduced into 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 the above circumstances, and it is possible to efficiently guide cold fresh air to the air cleaner and increase the filling efficiency of intake air. There is no need to open the opening, which simplifies the structure and prevents rainwater from being sucked in.Also, even if the fresh air inlet is opened toward the front, the dynamic pressure of the traveling wind is applied to the air cleaner. To provide an air intake device for a motorcycle, which can prevent the effects of air flow and allow a large-capacity air intake chamber to be easily arranged by using the dead space created around a head pipe.

[Means for Solving the Problems] Therefore, in the present invention, the front end of the frame is provided with a head pipe for pivotally supporting the front fork, and this head pipe has left and right pipes that extend downward while expanding in the left and right direction as it moves rearward. A pair of main pipes are connected, and the engine is placed below these main pipes.A cowling covers the head pipe and the upper part of the front fork from the front to the left and right sides, and the front fork is placed between the left and right side walls of the cowling. In the motorcycle, the left and right side walls of this cowling are extended toward the rear of the front fork, and the left and right extensions of this cowling cover the front half of the main pipe from the side. Immediately after the head pipe, an air cleaner connected to the engine is arranged, and a pair of left and right intake system parts for guiding fresh air to the air cleaner are arranged along the front-rear direction inside the left and right side walls of the cowling, An intake port is opened forward at the front end of each of these intake system components to take in fresh air, and the intake port of this intake system component is located between the left and right side walls of the cowling and below the head pipe. , the left and right intake system parts are provided with intake chambers located between the intake port and the air cleaner, respectively, and these intake chambers are connected to the left and right main pipes when the frame is viewed from above. The cowling is characterized by being disposed in a space surrounded by the front half of the cowling and the extension of the cowling, which has a shape that expands toward the front.

[Function] According to this configuration, the intake system component that introduces fresh air to the air cleaner has an intake port for introducing fresh air that
Since it is opened forward at a low position between the side walls of the cowling, cold running wind from the front flows into the cowling from the lower edge of the side wall while driving.
In other words, fresh air is directly guided to the intake ports of the intake system components. Therefore, a sufficient amount of fresh air efficiently flows into the air cleaner through the intake system components, and the temperature of the air sucked into the engine can be kept low.

Moreover, since there is no need to provide a special opening in the cowling to take in fresh air, the structure of the cowling can be simplified and costs can be reduced.

Furthermore, since the intake ports of the intake system parts are opened in the area surrounded by the cowling, rainwater is blocked by the cowling both when the vehicle is running and when the vehicle is stopped. can be prevented.

Further, since a large-capacity intake chamber exists in the flow path of fresh air taken in from the intake port, dynamic pressure of the traveling wind is difficult to act on the air cleaner even if the intake port is opened forward. Since this intake chamber is housed in the space created between the main pipe and the extension of the cowling, there is no need to secure a special space inside the frame for arranging the intake chamber. At the same time, the arrangement density of parts inside the frame is lower than when the intake chamber is arranged inside the frame, and mutual interference with various parts arranged around the engine can be prevented.

Furthermore, since the above-mentioned space expands as it moves forward, it is possible to secure a large capacity for the intake chamber, and the dead space created between the frame and the cowling can be effectively used as the installation area for the intake chamber. can do.

Since the intake chambers are located on both the left and right sides of the air cleaner, the air cleaner and the intake chamber are close to each other, and a series of intake system parts from the air cleaner to the intake port are arranged all together around the head pipe. I can do it.

[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. The head pipe 2 includes a pair of left and right main pipes 3 that extend rearward.
A down tube 4 extending downward is joined to the down tube 4. As shown in FIGS. 3 and 4, the main pipe 3 extends downward while expanding in the left-right direction as it goes rearward, and its width in the left-right direction reaches its maximum at the middle part of the main pipe 3. It's summery. 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 portion of a rear arm 6 is pivotally supported on the bracket 5 via a pivot shaft 7. A rear wheel 8 is supported at the rear end of the rear arm 6.

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, and both of these brackets 11 and 12 are connected to a steering shaft. 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 extending forward. This support stay 1
5 includes instruments 17 such as a headlamp 16 and a speedometer.
is installed.

Also, in the space surrounded by the main pipe 3 and down tube 4 of the frame 1, an engine 2
0 is installed. Engine 20 of this embodiment
is a water-cooled, four-cycle, four-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 disposed immediately after the head pipe 2, and the air cleaner 24 passes between the left and right main pipes 3 and projects above these main pipes 3. For this reason, the air cleaner 24 has a triangular shape that tapers toward the front when viewed from above.
The intake pipe 23 passes through the lower surface of the intake pipe 23 .

Note that the air cleaner 24 is surrounded by a cover 25 that forms the shape of a fuel tank, and this cover 25 is connected to a seat 26.

On the other hand, a synthetic resin cowling 30 is attached to the front end of the frame 1. The cowling 30 includes a main body 31 that covers the head lamp 16 and the gauges 17 in front of the head pipe 2, and a pair of left and right side walls 32 extending rearward from both left and right sides of the main body 31. The front fork 9 is inserted therethrough.
The side wall portion 32 of the cowling 30 is further extended toward the rear of the front fork 9, and this extended portion 32a covers the front half of the main pipe 3 and the upper part of the down tube 4 from the side.
In this cowling 30, the rear end portion of the extension portion 32a is connected to the main pipe 3 and the down tube 4.
The lower front end of the main body 31 is fixed to a bracket 35 welded to the head pipe 2 via a screw 36.

Side wall portion 32 of cowling 30 and main pipe 3
As shown in FIG. 3, a space 37 is secured between the two. This space portion 37 has a shape that expands forward when the frame 1 is viewed in a plan view because the main pipe 3 expands in the left and right directions as it advances rearward. . In this space 37, the front fork 9
A pair of left and right intake chambers 38 having a large capacity are arranged at positions outside the rotation locus. The intake chamber 38 is made of synthetic resin material,
It is supported on the inner surface of the side wall portion 32 via a support 43 . A communication passage 40 toward the air cleaner 24 is connected to the inner surface of each of the intake chambers 38 . 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.
An element 42 surrounding the opening of the communication port 41 is housed inside.

An intake duct 39 protruding forward is provided on the front surface of the intake chamber 38 . Intake duct 39
extends in the front-rear direction along the inner surface of the side wall portion 32, and the front end of this intake duct 39 is formed with an intake port 39a that opens toward the front. The intake duct 39 extends forward on both left and right sides of the front fork 9, and its intake port 39a is
It is located below the head pipe 2 when the motorcycle is viewed from the side. The intake port 39a is close to the lower edge 33 of the side wall 32 of the cowling 30, and is oriented forward at a low position between the side walls 32.

Therefore, in the case of this embodiment, the above-mentioned intake port 3
The air intake duct 39 and the communication passage 40 equipped with the air intake port 9a constitute air intake system components that lead fresh air to the air cleaner 24.
The intake chamber 38 is located in the middle of the fresh air flow path leading to the air intake chamber 4. Therefore, during engine operation, fresh air sucked in from the intake port 39a expands within the intake chamber 38 and is then guided to the air cleaner 24 via the communication path 40. 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.

In addition, as shown in Fig. 2, the intake chamber 3
The side wall portion 32 covering the air inlet 8 is curved inward as it advances upward, and projects above the intake port 39a, and the intake duct 39 having the intake port 39a is covered from above by this projecting portion 32b.

According to this configuration, the left and right intake ducts 39 for guiding fresh air to the air cleaner 24 have their front end intake ports 39a opened forward at a low position close to the lower edge 33 of the side wall 32. Therefore, while driving, cold fresh air from the front flowing into the cowling 30 from the lower edge 33 of the side wall 32 is
The air is directly guided to the intake port 39a, and from there to the air cleaner 24 via the intake chamber 38 and the communication passage 40.

Therefore, a sufficient amount of fresh air flows into the air cleaner 24 efficiently, and the temperature of the air taken into the engine 20 can be suppressed accordingly. Therefore, the filling efficiency of intake air can be increased, and the engine output can be improved.

Moreover, the fresh air flows through the side wall portion 32 of the cowling 30.
Since the air is led to the intake port 39a between the lower edges 33 of the cowling 30, there is no need to provide a special opening in the cowling 30 to take in fresh air. Therefore, the shape of the cowling 30 can be simplified, contributing to cost reduction. Along with that, cowling 3
The outer surface of 0 is also smooth with few irregularities, which has the advantage of being convenient in terms of appearance.

Furthermore, since the intake port 39a is located below the head pipe 2 when viewed from the side, the area around the intake chamber 38 from the intake port 39a is covered by the cowling 30. Therefore, rainwater is blocked by the cowling 30 both when the vehicle is running and when the vehicle is stopped, and this rainwater is prevented from being sucked into the air intake port 39a and eventually into the air cleaner 24.

Furthermore, in the above configuration, since the intake chamber 38 with a large capacity exists in the middle of the flow path of fresh air taken in from the intake port 39a, even if the intake port 39a is opened forward, the movement of the traveling wind The pressure is absorbed and relieved in the intake chamber 38,
Dynamic pressure can be prevented from acting on the air cleaner 24.

At the same time, the left and right intake chambers 38 are
Extension part 32a of main pipe 3 and cowling 30
Since it is arranged in the space 37 created between the intake chamber 38 and the intake chamber 38, there is no need to secure a space for installing the intake chamber 38 inside the frame 1 surrounded by the main pipe 3 and the down tube 4. Therefore, the arrangement density of parts inside the frame 1 is reduced, and mutual interference between various functional parts arranged inside the frame 1 and the intake chamber 38 can be prevented, and various parts including the intake chamber 38 can be arranged at a low density. Part arrangement and maintenance become easier.

Further, since the space 37 in which the intake chamber 38 is installed expands as it moves forward according to the bending shape of the main pipe 3, the space 37 has a sufficient width, so that the intake chamber 38 is Large capacity can be secured. Therefore, it is possible to reduce intake noise and improve intake performance, and the frame 1 and cowling 30
The dead space created between the two can be effectively used as a location for installing the intake chamber 38.

In addition, since the left and right intake chambers 38 are located on both the left and right sides of the air cleaner 24, a series of intake system components from the air cleaner 24 to the intake duct 39 are gathered around the head pipe 2. Therefore, the flow path of fresh air from the intake port 39a to the air cleaner 24 is shortened, and intake resistance can be suppressed accordingly.

Although the above embodiment describes the case where the intake chamber 38 is fixed to the cowling 30 via the support 43, the present invention is not limited to this.
For example, the intake chamber 38 may be fixed to the frame 1, as in other embodiments shown in FIGS. 5 and 6.

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 with screws 50.

[Effects of the Invention] According to the present invention described in detail above, the cold fresh air that flows into the cowling from between the side walls of the cowling while driving is guided directly to the intake port of the intake system parts, so that the air cleaner A sufficient amount of fresh air can efficiently flow into the engine through the intake system parts, thereby lowering the temperature of the air taken into the engine and increasing the filling efficiency of the intake air.

Furthermore, since there is no need to provide a special opening in the cowling to take in fresh air, the shape of the cowling can be simplified and costs can be reduced.

Furthermore, since the intake ports of the intake system parts are covered by the cowling, rainwater is blocked by the cowling both when the vehicle is running and when the vehicle is stopped, and this rainwater is not sucked into the intake system parts. It has the advantage of being

Furthermore, fresh air taken in from the intake port is guided to the air cleaner through the intake chamber, so even if the intake port is opened forward, the dynamic pressure of the wind is absorbed and alleviated by the intake chamber, reducing the dynamic pressure. This can prevent the air cleaner from being affected. At the same time, there is no need to secure space for installing the intake chamber inside the frame, so the arrangement density of parts inside the frame is reduced, and the various functional parts and intake chambers placed inside the frame are In addition to preventing mutual interference with the intake chamber, the arrangement and maintenance of various parts including the intake chamber are facilitated.

Further, since the space in which the intake chamber is installed expands as it moves forward according to the bent shape of the main pipe, a large capacity of the intake chamber can be ensured. Therefore,
Not only can intake noise be reduced and intake performance improved, but also the dead space created between the frame and the cowling can be effectively used as an installation location for the intake chamber.

In addition, since the intake chamber is located on both the left and right sides of the air cleaner, a series of intake system parts from the air cleaner to the intake duct are gathered around the head pipe, which shortens the flow path of fresh air upstream of the air cleaner. This allows the intake resistance to be kept low.

[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, 3...
Main pipe, 9...Front fork, 20...
... Engine, 24 ... Air cleaner, 30 ... Cowling, 32 ... Side wall part, 32a ... Extension part,
37...Space part, 38...Intake chamber, 3
9,40...Intake system parts (intake duct, communication path),
39a...Intake port.

Claims (1)

[Scope of Claims] 1. A head pipe for pivotally supporting the front fork is provided at the front end of the frame, and a pair of left and right main pipes are connected to this head pipe, which extend downward in the left and right directions as they move rearward. The engine is placed below the main pipe, and a cowling covers the head pipe and the upper part of the front fork from the front to both left and right sides.The front fork is inserted between the left and right side walls of this cowling, and the left and right sides of this cowling are In a motorcycle in which the side wall portion of the cowling extends toward the rear of the front fork, and the left and right extensions of the cowling cover the front half of the main pipe from the side, an air cleaner connected to the engine is installed immediately after the head pipe. At the same time, a pair of left and right intake system parts for guiding fresh air to the air cleaner are arranged inside the left and right side walls of the cowling. The mouth of the intake system component is opened forward, and the intake port of the intake system component is positioned below the head pipe between the left and right side walls of the cowling. An intake chamber is provided between the air cleaner and the air cleaner, and when the frame is viewed from above, the intake chamber is located at the front side surrounded by the front half of the left and right main pipes and the extension of the cowling. An intake device for a motorcycle, characterized in that the air intake device is arranged in a space portion having a shape that expands toward the air.