JP2986849B2 - Motorcycle engine intake system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle engine intake device having an intake chamber for introducing a traveling wind.

(Prior Art) As the above-mentioned intake device, there is a conventional one disclosed in, for example, Japanese Utility Model Laid-Open No. 58-192121.

According to the publication, an intake chamber extending in the front-rear direction is provided on the side of the vehicle body. An air inlet is formed at a front end of the intake chamber, and the air inlet is located behind a front fork and a front wheel. And
The traveling wind is introduced into the intake chamber from the air inlet, and is sucked into the engine from the rear end.

An exhaust pipe extending rearward from the engine is provided, and a cowling is provided to cover the intake chamber and a front part of the exhaust pipe from outside.

(Problems to be solved by the invention) By the way, according to the above-mentioned conventional technology, there are the following problems.

First, since the air inlet is located behind the front fork and the front wheels, traveling wind disturbed by these front forks and front wheels is introduced into the intake chamber through the air inlet. As a result, the use of the dynamic pressure of the traveling wind may hinder the improvement of the engine charging efficiency.

In addition, foreign matter such as sand jumped up by the front wheels may jump into the intake chamber through the air inlet and damage the engine.

Second, assuming that an exhaust pipe is provided near the intake chamber in the vehicle width direction, air introduced into the intake chamber is easily heated by the heat of the exhaust pipe,
The filling efficiency of the engine may be reduced.

Third, in order to improve the charging efficiency of the engine and to prevent foreign substances jumped up by the front wheels from jumping into the intake chamber through the air inlet, the front end of the intake chamber extends forward. It is conceivable that the air introduction port is moved forward to position the air introduction port further forward.

However, if the front end of the intake chamber simply extends forward, the extension of the intake chamber protrudes greatly from the cowling to the front, so that the extension can be easily seen in appearance. It is not preferable in terms of appearance of the motorcycle.

Fourth, since the intake chamber is covered with a cowling from outside, the cowling may hinder the cooling of the intake chamber by traveling wind. Air may be easily heated by the heat of the exhaust pipe.

(Purpose of the Invention) The present invention has been made in view of the above circumstances, and has the following objects.

First, the dynamic pressure of the traveling wind is effectively used to improve the charging efficiency of the engine, and also to prevent foreign matter jumped up by the front wheels from jumping into the intake chamber to prevent damage to the engine.

Secondly, a decrease in the charging efficiency of the engine due to the heat of the exhaust pipe is suppressed.

Third, the appearance of the motorcycle can be kept good even when the filling efficiency of the engine is improved and foreign matter jumped up by the front wheels is prevented from jumping into the intake chamber.

Fourth, even if the air introduced into the intake chamber is heated by the heat of the exhaust pipe, the air is cooled by the traveling wind to suppress a decrease in the charging efficiency of the engine.

(Structure of the Invention) A feature of the present invention for achieving the above object is that an engine 13 is arranged behind the front fork 4 and an intake opening 36 on the engine 13 side is opened toward the outside of the vehicle body. An intake chamber 15 extending substantially horizontally in the front-rear direction at the side of the vehicle body is provided, and an air inlet 41 is formed at a front end thereof, while a rear end of the intake chamber 15 is connected to an intake opening 36 at the engine 13 side. Exhaust pipe 16 extending backward from 13
A cowling 30 that covers the intake chamber 15 from the outside thereof, and a running wind discharge port 46 that connects a space inside the cowling 30 to the outside thereof is provided with the cowling 30.
30) A motorcycle formed in 30. 1) An air inlet of an intake chamber is positioned outside each of the front fork and the front wheel, and the air inlet is positioned so as to overlap with the front fork in a side view of the vehicle body. 2) The exhaust pipe 16 is disposed on the opposite side of the intake chamber 15 with respect to the front wheel 5 in the vehicle width direction. 3) The cowling 30 located at the same position as the intake chamber 15 in the vertical direction. Of the front wheel 5
And 4) the traveling wind discharge port 46 is located near the rear end of the intake chamber 15.

(Operation) The operation of the above configuration is as follows.

An engine 13 is disposed behind the front fork 4, an intake opening 36 on the engine 13 side is opened toward the outside of the vehicle body, and an intake chamber 15 extending substantially horizontally in the front-rear direction on the side of the vehicle body is provided. While forming an air inlet 41 in the part, the rear end is connected to the intake opening 36 on the engine 13 side,
An exhaust pipe 16 extending rearward from the engine 13 is provided, a cowling 30 is provided to cover the intake chamber 15 from the outside, and a traveling wind exhaust port 46 connects a space inside the cowling 30 to the outside. In the motorcycle formed on the cowling 30, 1) an air inlet of the intake chamber is located outside each of the front fork and the front wheel, and the air inlet overlaps the front fork in a side view of the vehicle body. It is located.

Therefore, the traveling wind 44 is smoothly introduced into the intake chamber 15 through the air inlet 41 without being disturbed by the front fork 4 and the front wheel 5. Therefore, the dynamic pressure of the traveling wind 44 is effectively used for intake of the engine 13.

In addition, the front end of the intake chamber 15 extends to the outside of the front fork 4 and the front wheel 5, so that the intake chamber 15 has a sufficient length as compared with the related art, so that the intake chamber 15 has a sufficient capacity. Therefore, also at this point, the dynamic pressure of the traveling wind 44 is effectively used for the intake of the engine 13.

Further, since the air inlet 41 is located outside the front wheel 5 as described above, foreign matter jumped up by the front wheel 5 is suppressed from jumping into the intake chamber 15 through the air inlet 41. .

2) The exhaust pipe 16 is provided on the opposite side of the intake chamber 15 with respect to the front wheel 5 in the vehicle width direction.

For this reason, compared with the case where the exhaust pipe 16 is located on the same side as the intake chamber 15 in the vehicle width direction, the exhaust pipe 16 is farther away from the intake chamber 15, and The air introduced is above the exhaust pipe
It is prevented from being heated by the heat of 16.

3) The front end of the cowling 30 located at the same position as the intake chamber 15 in the up-down direction is located outside the upper part of the front wheel 5.

Therefore, as described above, when the air inlet 41 at the front end of the intake chamber 15 is to be positioned outside the front fork 4 and the front wheel 5, the front end of the intake chamber 15 is extended forward. However, almost the entire extension of the intake chamber 15 is covered with the cowling 30.

Therefore, it is possible to prevent the extension of the intake chamber 15 from being easily seen in appearance.

4) The traveling wind exhaust port 46 is connected to the intake chamber 15
Is located near the rear end.

For this reason, the traveling wind 44 that flows into the space inside the cowling 30 from the front thereof and then travels toward the outside of the cowling 30 through the traveling wind discharge port 46 is applied to the outer surface of the intake chamber 15. It tends to flow along.

Therefore, even if the air introduced into the intake chamber 15 is heated by the heat of the exhaust pipe 16, the air is:
The air is cooled by the traveling wind 44.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a motorcycle, and a body frame 2, which is a body of the motorcycle, has one main frame 3, and the main frame 3 has a box-shaped cross section and has a downwardly falling shape. . A front fork 4 is supported at the front end of the main frame 3 so as to be steerable. A front wheel 5 is supported on a lower end of the front fork 4, and a handle 6 is mounted on an upper end of the front fork 4.

A pair of left and right rear arm brackets 8 and 8 are integrally formed downward from the rear end of the main frame 3, and a rear arm 10 is pivotally mounted on the rear arm brackets 8 and 8 by a pivot shaft 9 so as to be vertically swingable. Supported by this rear arm
An intermediate portion of 10 is supported by the main frame 3 via a shock absorber 12. The swinging end of the rear arm 10 has a rear wheel 11
Is supported.

Reference numeral 13 denotes a two-cycle engine. A power transmission device 14 is connected to the engine 13, and the engine 13 and the power transmission device 14 are supported by the rear portion of the main frame 3 and the lower portions of the rear arm brackets 8, 8. I have. The cylinder 13a of the engine 13 projects forward and has an intake chamber 15 extending substantially horizontally in the front-rear direction on the side of the vehicle body. A rear end of the intake chamber 15 is connected to the engine 13 side.

An exhaust port is opened on the lower surface of the cylinder 13a, and an exhaust pipe 16 extends rearward from the exhaust port. In this case, substantially the entire exhaust pipe 16 is disposed on the side opposite to the intake chamber 15 with respect to the front wheel 5 in the vehicle width direction. Further, the inside of the main frame 3 serves as a fuel tank, from which fuel is supplied to the engine 13. The main frame 3 and the engine
A radiator 17 is provided in front of a space between the radiators 13 and 13.

The rear wheel 11 is linked to the power transmission device 14 by a chain winding means 19, and the rear wheel 11 is connected to the power transmission device 14 and the chain winding means 19 by the operation of the engine 13.
Is driven to travel.

A cover body 20 is provided to cover the main frame 3 from above. The cover body 20 is detachably supported on the main frame 3 by front and rear bolts 21, 21. In addition, a sheet 22 is integrally formed at the rear end of the cover body 20, and this sheet 22
Is firmly supported on the main frame 3 side via the cover body 20, and the seat 22 is also pivotally supported by a pivot shaft 24 on the upper end of a support bar 23 protruding from the rear of the exhaust pipe 16. ing.

Further, a footrest bracket 26 projects rearward from the lower end of each of the rear arm brackets 8, and a footrest 27 is attached to a projecting end of each of the footrest brackets 26. Then, a rider 28 in a riding position sitting on the seat 22 puts his foot 29 on the footrest 27. A resin cowling 30 is provided to cover the upper part of the body frame 2, the front fork 4, the intake chamber 15, and the front part of the exhaust pipe 16 from the front and outside.

The engine 13, the cowling 30, and the intake device of the engine 13 will be described in more detail with reference to FIGS.

In particular, in FIG. 4, the engine 13 has a cylinder 33 that projects horizontally forward from a crankcase 32, and an intake port 34 is formed on the left side wall of the crankcase 32. It is formed so that the inflow of the intake air into the inside 32 can flow with a small resistance.

35 is an intake pipe, the lower end of the intake pipe 35 is attached to the left side surface of the crankcase 32, the inside communicates with the intake port 34, the upper end side of the intake pipe 35 is the left outside of the vehicle body, Further, it extends upward, and its upper end is an intake opening 36 on the engine 13 side, and the intake opening 36 opens toward the outside of the vehicle body. A throttle valve 37 and a fuel injection valve 38 are attached to the intake pipe 35. The throttle valve 37 is linked to a grip 39 attached to the handle 6, while the fuel injection valve 38 is connected to the main frame 3
Fuel pumped from the fuel tank formed in the intake pipe
Through 35, the fuel is injected into the crankcase 32 as appropriate.

1 to 3, the intake chamber 15 is made of resin and has a cylindrical shape with a circular cross section as a whole, and has an air inlet 41 which is opened forward at its front end. In this case, in order to keep the width of the vehicle body small, the air inlet 41 has an elliptical shape that is long vertically. Further, the opening at the rear end of the intake chamber 15 is closed by a semicircular closing lid 42, and a branch pipe 43 projects downward from the lower surface of the rear end of the intake chamber 15; The lower end of 43 is connected to the intake opening 36 at the upper end of the intake pipe 35.

The air inlet 41 is located near the outside of the front fork 4 at a substantially central position in the vertical direction, and is located near the outside of the upper portion of the front wheel 5. The mouth 41 is positioned so as to overlap the front fork 4 in a side view of the vehicle body. That is, the traveling wind 44 is smoothly introduced into the intake chamber 15 through the intake opening 36 without being disturbed by the front forks 4 and the front wheels 5.

The intake chamber 15 is provided substantially linearly and substantially horizontally from the front end toward the rear. For this reason, the traveling wind 44, which is the air flowing backward in the horizontal direction in front of the vehicle body, flows through the air inlet 41 into the intake chamber 15.
When flowing into the crankcase 32, the traveling wind 44 reaches the rear end of the intake chamber 15 without substantially changing the flowing direction, and from there, sequentially passes through the intake pipe 35 and the intake port 34 into the crankcase 32. Inhaled.

In the above case, the traveling wind flowing backward in the intake chamber 15
The gas 44 flows once so as to collide with the closing lid 42 at the rear end of the intake chamber 15, and then is sucked into the intake pipe 35. For this reason,
The dynamic pressure of the traveling wind 44 is prevented from directly acting on the crankcase 32, and the dynamic pressure of the traveling wind 44 is sufficiently converted into static pressure in the intake chamber 15, and this static pressure is Will act within. In this way, the charging efficiency of the engine 13 is accurately and effectively increased.

The intake chamber 15 has a front end located outside the front fork 4 and a rear end extending toward the engine 13 located forward of the footrest 27. In this way, the intake chamber 15 has a sufficient length within a range that does not interfere with the foot 29 of the rider 28 in the riding posture. That is, a sufficient capacity is secured in the intake chamber 15.

Further, as described above, the intake chamber 15 is provided substantially linearly and substantially horizontally from the front end thereof toward the rear, so that the area of the intake chamber 15 in front view is suppressed to be small. That is, an increase in air resistance due to the traveling wind is suppressed.

In particular, as shown in FIG.
15 is screwed by a bolt 50 via a cushion rubber 49 to a bracket 48 protruding from the main frame 3 at a middle part in the front-rear direction. This screwing and the rear end of the intake chamber 15 are It is fixed by being connected to the intake pipe 35 as described above. In addition, a shimmy damper 51 is attached to the bracket 48 so as to absorb the vibration that is likely to occur in the intake chamber 15.

1 to 3, the cowling 30 has a U-shape that opens rearward in a plan view.
The left side of 30 entirely covers the intake chamber 15 from the outside. An insertion hole 45 is formed at the left front end of the cowling 30, and the front end of the intake chamber 15 is protruded forward from the front end of the cowling 30 through the insertion hole 45. In this case, the front end of the portion of the cowling 30 located at the same position as the intake chamber 15 in the up-down direction (portion where the insertion hole 45 is formed)
Is located outside the upper part of the front wheel 5, and
The intake chamber 15 is located near the rear of the front end.

On the left and right sides of the cowling 30, running air discharge ports 46 and 47 are formed to connect the space inside to the outside of the cowling 30, respectively. In particular, as shown in FIG. 3, the traveling wind 44 flowing into the space inside the cowling 30 from the front thereof is discharged to the outside of the cowling 30 through the traveling wind discharge ports 46, 47 and the like. It is supposed to be. In this case, the traveling wind discharge port 46 is located near the rear end of the intake chamber 15.

By the way, since the cowling 30 has a U-shape in plan view as described above, when the cowling 30 is to be assembled on the body frame 2 side, the cowling 30
From the front of the body frame 2 side.
Move it almost horizontally toward the side and assemble it. In this case, as described above, the intake chamber 15 is provided linearly toward the rear and substantially horizontally. For this reason, the direction in which the cowling 30 is moved coincides with the direction in which the intake chamber 15 extends.

Therefore, at the time of assembling the cowling 30, the insertion hole 45 of the cowling 30 can be easily fitted to the front end of the intake chamber 15, so that the cowling 30 can be fitted.
Can be easily assembled.

In addition, as shown in FIG. 1 and FIG.
A master cylinder 52 operated by a manual lever is attached to the left side of the master cylinder 52.

Although the above description is based on the illustrated example, the front end of the intake chamber 15 may protrude slightly forward from the front fork 4.

(Effects of the Invention) According to the present invention, an engine is disposed behind a front fork, and an intake opening on the engine side is opened toward the outside of the vehicle body. A chamber is provided and an air inlet is formed at a front end thereof, while a rear end is connected to an intake opening on the engine side, and an exhaust pipe extending rearward from the engine is provided. A motorcycle provided with a cowling that covers the inside of the cowling and having a running wind discharge port formed in the cowling to communicate a space inside the cowling with the outside thereof. 1) Air in an intake chamber is provided outside each of the front fork and the front wheel. The inlet is located, and the air inlet is positioned so as to overlap the front fork in a side view of the vehicle body.

For this reason, the traveling wind is smoothly introduced into the intake chamber through the air introduction port without being disturbed by the front fork and the front wheels. Therefore, the dynamic pressure of the traveling wind is effectively used for intake of the engine, and the charging efficiency of the engine is improved.

In addition, the front end of the intake chamber extends to the side of the front fork and the front wheel, so that the intake chamber has a sufficient length as compared with the related art. That is, a sufficient capacity is secured in the intake chamber. Therefore, also at this point, the dynamic pressure of the traveling wind is effectively used for intake of the engine, and the charging efficiency is further improved accordingly.

Further, as described above, the air inlet is located outside the front wheel. For this reason, the foreign matter jumped up by the front wheels is suppressed from jumping into the intake chamber through the air inlet, thereby preventing the engine from being damaged.

2) The exhaust pipe is disposed on the side opposite to the intake chamber with respect to the front wheels in the vehicle width direction.

For this reason, compared with the case where the exhaust pipe is located on the same side as the intake chamber in the vehicle width direction, the exhaust pipe is farther away from the intake chamber, and the air introduced into the intake chamber is reduced. Heating by the heat of the exhaust pipe is prevented.

Therefore, a decrease in the charging efficiency of the engine due to the heat of the exhaust pipe is suppressed.

Further, 3) the front end of the portion of the cowling located at the same position as the intake chamber in the up-down direction is located outside the upper portion of the front wheel.

For this reason, even if the front end of the intake chamber is extended forward in order to position the air inlet at the front end of the intake chamber outside the front fork or the front wheel as described above, even if the front end of the intake chamber extends forward, Almost the entire extension is covered with the cowling.

Therefore, the extension of the intake chamber is prevented from being easily seen in appearance, and the appearance of the motorcycle is kept good.

4) The traveling wind discharge port is located near the rear end of the intake chamber.

For this reason, the traveling wind that flows into the space inside the cowling from the front of the cowling and then travels toward the outside of the cowling through the traveling wind discharge port tends to flow along the outer surface of the intake chamber. Becomes

Therefore, even if the air introduced into the intake chamber is heated by the heat of the exhaust pipe, the air is cooled by the traveling wind, and therefore, a decrease in the charging efficiency of the engine is suppressed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an overall side view, FIG. 2 is a partial front sectional view, FIG.
The figure is a partially enlarged sectional view of FIG. 1 ... motorcycle, 2 ... body frame, 4 ... front fork, 5 ... front wheel, 13 ... engine, 15 ... intake chamber, 16 ... exhaust pipe, 27 ... footrest, 28 ...
Rider, 29 feet, 30 cowling, 36 intake opening, 41 air inlet, 44 wind, 46 wind exhaust.

Claims (1)

(57) [Claims] An engine is arranged behind a front fork, an intake opening on the engine side is opened toward the outside of the vehicle body, and an intake chamber extending substantially horizontally in the front-rear direction on the vehicle body side is provided. While forming an air inlet in the part, a rear end is connected to the intake opening on the engine side, an exhaust pipe extending rearward from the engine is provided, and a cowling that covers the intake chamber from the outside is provided. In a motorcycle having a running wind discharge port formed in the cowling for communicating a space inside the cowling to the outside thereof, 1) an air inlet of an intake chamber is positioned outside each of the front fork and the front wheel; And the air inlet is positioned so as to overlap the front fork in a side view of the vehicle body. 2) In the vehicle width direction, the intake chamber is referenced with respect to the front wheels. Disposes the exhaust pipe on the opposite side; 3) positions the front end of the portion of the cowling, which is located at the same position as the intake chamber in the vertical direction, outside the upper part of the front wheel; An intake device for an engine of a motorcycle, wherein a traveling wind outlet is located near a rear end of the intake chamber.