JP2712014B2 - Motorcycle air intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air intake system for a motorcycle equipped with a V-type engine.

[0002]

2. Description of the Related Art An intake device including an air cleaner, a carburetor, and an intake pipe is a device that supplies an appropriate air-fuel mixture including clean air into a cylinder of an engine. Is provided. The smaller the intake device is, the easier it is to provide it on a motorcycle, but it is desired that the air cleaner of the device has a sufficient size (volume). This is because, when the volume of the air cleaner is small, the pulsation of the intake air accompanying the reciprocation of the piston in the cylinder becomes intense, so that the noise (intake noise) increases and the acceleration response decreases. The air cleaner is also required to be close to the cylinder and cylinder head of the engine, and to be located at a position where maintenance of the filter element and the like can be easily performed.

Considering such conditions, the so-called V
In a motorcycle in which a type engine is mounted horizontally (that is, a configuration in which a crankshaft is directed to the left and right of the vehicle body, and a cylinder is inclined in front and rear of the vehicle body), it is not easy to appropriately arrange an intake device. In a V-type engine, since a plurality of cylinders are spread in front, rear, left and right, it is difficult to arrange an air intake device including an air cleaner having a sufficient volume in a space and a preferable manner in terms of function and appearance. Therefore, various arrangements have conventionally been made for the arrangement of the intake device in a motorcycle having a V-type engine placed sideways, and many proposals have been made.

The invention described in Japanese Patent Application Laid-Open No. 61-93264 is one of such proposals. As shown in FIG. 3, the invention of this publication discloses an air cleaner 12 ′, intake pipes 13 ′ and 15 ′, and a carburetor 1 above a V-type engine 3 ′, that is, between the inclined front and rear cylinders 3 A ′ and 3 B ′.
6 'and an air intake device 10' including a connection box 14 'and the like. The connection box 14 'is a container (suction chamber) connected to the downstream side of the air cleaner 12' in order to weaken the pulsation of the intake air without increasing the volume of the air cleaner 12 'itself.

[0005] In addition, some proposals have already been made to provide only an air cleaner of an intake device on the side of the engine, that is, on the right or left side of the engine when viewed in the traveling direction of the vehicle body. There are many.

[0006]

When an intake device is arranged between cylinders of a V-type engine as shown in FIG. 3, it is often necessary to sacrifice the capacity of a fuel tank located above the intake device. The fuel tank is usually located above the engine, but if the intake system is provided between the cylinders (ie, above the engine) and the air cleaner (or a junction box that makes up the volume) has enough volume, the usual This is because the intake device cannot fit between the bottom of the fuel tank and the engine. In the example of FIG. 3 as well, the bottom surface (bottom plate 4a ') of the fuel tank 4' is formed considerably above the lowermost portion on the outer shape, and the capacity is considerably small. In the case of FIG. 3, the front and rear cylinders 3A 'and 3B'
This is an example in which the interposed angle (the angle of the V bank) is large and it is easy to take up space between the cylinders. Often it will be smaller.

On the other hand, when an air cleaner is provided on the right or left side of the V-type engine, when the air cleaner is provided with a large volume, it protrudes to the left or right and approaches the driver's leg or becomes particularly noticeable in appearance. And the appearance of motorcycles gets worse.

An object of the present invention is to provide an air cleaner with a sufficient volume without sacrificing the capacity of a fuel tank.
It is another object of the present invention to provide an intake device for a motorcycle in which air cleaners and the like are arranged on the left and right sides of a vehicle body in a well-balanced manner.

[0009]

According to a first aspect of the present invention, a V-type engine is mounted by tilting a cylinder forward and backward of a vehicle body (that is, the V-type engine is placed horizontally). An intake device provided in a motorcycle, in which an air cleaner and an intake chamber connected to a downstream side thereof are separately arranged on the left and right sides of the engine, one by one, and the air cleaner is passed between the front and rear cylinders inclined as described above. They are connected by a duct (intake pipe). In addition, “the left and right sides of the engine” means positions adjacent to the left and right sides of the engine mounted on the vehicle body. “Separate left and right” does not mean which of the air cleaner and the intake chamber is left or right.

[0010] Since this air intake device does not provide an air cleaner above the V-type engine (between the front and rear cylinders), even if the air cleaner has a sufficient volume, it does not protrude significantly above the engine. Although a duct connecting the air cleaner and the intake chamber is passed between the front and rear cylinders, the duct does not need to have a larger cross-sectional area than the air cleaner and the intake chamber. Therefore, according to this intake device,
Even when there is a fuel tank above the engine, it is possible to increase the capacity of the tank. Further, since the air cleaner is not disposed between the cylinders, the air cleaner can be disposed even when the angle of the V bank formed by the cylinder is small, and the volume of the air cleaner can be increased.

Since the intake chamber is connected to the downstream side of the air cleaner, even if the air cleaner itself does not have a sufficient volume, if the total volume with the intake chamber can be secured, the pulsation of the intake air can be reduced, and the intake noise can be reduced. And the engine response can be improved. Of course, in order to obtain such an effect, a considerable volume is also required for the intake chamber, but in the case of this intake device where the air cleaner and the intake chamber are separated on the left and right sides of the engine, The degree of protrusion is small. Because the engine is mounted near the center of the body width due to weight balance, compared to installing a large volume air cleaner on either side of such an engine,
When the air cleaner and the intake chamber are provided separately on the left and right, even if the total volume of the two is equal to the volume of the single (large volume) air cleaner, the extent to which they protrude in the vehicle width direction is fairly moderate. It becomes something.
Therefore, in the intake device of the present invention, disadvantages such as an increase in the size of the air cleaner and the like and inconvenience in appearance are unlikely to occur.

The effect of suppressing the pulsation of the intake air to reduce the intake noise and improve the response is as described above when the intake chamber is connected to the downstream side of the air cleaner than when the intake chamber is connected to the upstream side. Is also remarkable.

According to a second aspect of the present invention, the duct is disposed so as to be inclined so as to connect an upper portion of the air cleaner and a lower portion of the intake chamber. The vaporizer is arranged between the cylinders.

In general, the duct performs a required function regardless of its cross-sectional shape if it has a certain cross-sectional area. Therefore, it is easy to arrange the duct through a portion closest to the bottom between the valleys of the cylinder. Therefore, as described above, in the portion near the intake chamber, the duct is passed downward (near the bottom of the valley), and if the carburetor is disposed thereon, the carburetor is provided very close to the cylinder and the valley between the cylinders is provided. This means that the space was effectively used. Moreover, since the carburetor and the duct are relatively small parts, there is little possibility that the carburetor and the duct protrude above the engine. However, since the duct is inclined and passes upward in a portion near the air cleaner away from the carburetor, it is possible to increase the cross-sectional area of the duct and reduce the intake resistance in the vicinity.

[0015]

1 and 2 show an embodiment of the present invention. FIG. 1A is a side view showing the intake device 10 together with the V-type engine 3 (with the intake chamber 14 removed),
(B) is a front view of the intake device 10 (b in (a)).
-B sectional view). FIG. 2 shows the intake device 10 of FIG.
FIG. 1 is a side view showing a main part of a motorcycle 1 equipped with a V-type engine 3.

As shown in FIG. 2, the motorcycle 1 is of a type in which a V-type two-cylinder engine 3 is mounted horizontally on a body frame 2. The engine 3 is provided between the upper pipe 2a at the upper part of the frame 2 and the down tube 2b at the front and lower parts, and the fuel tank 20 is mounted on the upper pipe 2a. Symbols 3A and 3B in the figure represent cylinders of the engine 3 and 3C
Represents the crankcase. The angle between the cylinders 3A and 3B is as small as about 50 °. 5A and 5B are exhaust pipes or mufflers from the cylinders 3A and 3B.

The intake device 10 for the engine 3 in the motorcycle 1 is configured as shown in FIG. That is, as shown in FIG. 1B, the air cleaner 12, the intake chamber 14, and the carburetor 16 are connected by an intake pipe 11, a duct 13, a suction pipe 15, and the like, which are intake pipes. The air cleaner 12 has a disk-shaped front case 12a and a back case 12b integrally assembled with bolts 12c, and a cylindrical filter element 12d mounted inside the case. That is, the air cleaner 12 filters the outside air taken in from the suction pipe 11 by the element 12d and sends the filtered air to the downstream duct 13 and the like. Further, an intake chamber 14 is connected further downstream of the duct 13. The intake chamber 14 has a front case 14a and a rear case 1 having substantially the same shape and dimensions as the air cleaner 12.
4b is also integrated with a bolt 14c and does not contain any elements or the like, but its internal volume is almost equal to the internal volume of the air cleaner 12. Since such an intake chamber 14 is connected to the downstream side of the air cleaner 12, the peak increase of the intake negative pressure during operation is suppressed despite the relatively small size of the air cleaner 12, and the pulsation of the intake air is reduced. Become calm. And such an intake chamber 14
Is connected to a carburetor 16 via a suction pipe 15. Although not shown, the downstream opening 16a of the carburetor 16 is connected to the inside of each of the cylinders 3A and 3B of the engine 3 via a short pipe.

A characteristic of the intake device 10 is that the air cleaner 12 and the intake chamber 14 formed in substantially the same shape and size as described above are connected to the left and right sides of the V-type engine 3 (the motorcycle 1).
(Left and right sides in the direction of travel). That is, the intake chamber 14 is provided at a position immediately to the right adjacent to both the cylinders 3A and 3B as shown in FIG. 1A or FIG.
The cylinders 3A and 3A are almost symmetrical with the intake chamber 14 as shown in FIG.
It was attached to the position just to the left of B. Each fixed
This is performed by screwing to the outer walls of the cylinders 3A and 3B.

The above point is that the volume required for weakening the pulsation of the intake air is divided into the air cleaner 12 and the intake chamber 14 so that the volume is not biased to one of them.
In addition, since both are assigned to the left and right sides of the engine 3, it is possible to avoid that one of the two protrudes greatly to the side of the engine 3 (or the vehicle body). Further, since the air cleaner 12 and the intake chamber 14 which have no difference in outer shape are provided symmetrically on the left and right sides of the vehicle body, and both have a circular shape when viewed from the side of the vehicle body, the appearance of the motorcycle 1 is particularly (Left and right)
When viewed from the viewpoint, it is unified and preferable. If the outer shape of the air cleaner is cylindrical or disk-shaped, generally a cylindrical filter element will be used inside.However, since cylindrical elements are widely marketed and commonly used, cost or handling The above is also advantageous. There is no manufacturing or functional disadvantage in making the intake chamber cylindrical or disk-shaped. In addition, if the air cleaner 12 is outside the engine 3 and its bolt 12c
Since the front case 12a faces outward, there is also an advantage that maintenance of the element 12d performed by removing them is easy.

Regarding the intake device 10, FIGS. 1 (a) and 1 (b)
As described above, the duct 13 connecting the air cleaner 12 and the intake chamber 14 is also arranged together with the carburetor 16 in the V-shaped valley between the cylinders 3A and 3B. Generally, the duct 13 has a certain cross-sectional area and performs a necessary function regardless of its cross-sectional shape (for example, an inverted triangular shape as shown). Even if the angle is quite narrow, it can be passed in the meantime. Therefore, cylinder 3
A and 3B share the carburetor 16 with the cylinder 3
A and 3B are provided at the valleys of the V-type for the purpose of placing them closest to each other.
-The duct 13 was able to be arrange | positioned through the part near the bottom part of the V-shaped valley corresponding to the base of 3B).
However, regarding the duct 13, it is preferable that the portion having a small cross-sectional area is shorter because the intake resistance can be reduced.
As described above, the left part where the carburetor 16 is not provided passes above the valley, and the sectional area of the part is slightly increased. That is, the upper part of the air cleaner 12 and the intake chamber 1
The duct 13 is arranged so as to be inclined so as to connect to the lower part of the intake chamber 4, and the carburetor 16 is arranged above the part of the duct 13 near the intake chamber 14 and connected to the upper part of the intake chamber 14. .

By arranging the carburetor 16 and the duct 13 in this manner, the space between the cylinders 3A and 3B can be used effectively even though the space between the cylinders is considerably narrow. Moreover, in this case, relatively small components (ie,
The carburetor 16 and the duct 13 (and the suction pipe 11 to be described later), which are parts that do not particularly require a volume in function.
Is provided in the valley, the intake device 10 hardly protrudes above the engine 3. Since the intake device 10 does not protrude upward, the fuel tank 4 above the engine 3
There was no need to reduce the capacity for. That is,
As shown in FIG. 2, the intake device 10 including the carburetor 16 is
Could be arranged without moving the bottom of the tank 4 particularly upward (under the recess of the bottom plate 4a formed so as to straddle the upper pipe 2a).

In addition to the above, in this intake device 10, in order to further reduce the intake noise, as shown in FIG.
Is opened toward the bottom of the fuel tank 4 (FIG. 2). Although the pulsation of the intake air is suppressed by the effect of the volume of the air cleaner 12 and the intake chamber 14, a large intake noise is unavoidable at the upstream end of the intake pipe 11 which takes in the outside air first. Is provided at the upper part of the air cleaner 12 and the upstream end thereof is provided at a position facing the bottom of the tank 4 and surrounded by the tank 4.
In other words, by using a soundproof wall, the divergence of the intake sound is suppressed. Also, by providing the tank under the tank 4, it is easy to prevent rainwater from entering from the upstream end.

[0023]

The intake system for a motorcycle according to the first aspect has the following effects. 1) Since the intake chamber is connected to the downstream side of the air cleaner, the pulsation of the intake air can be weakened by securing the total volume with the intake chamber even if the air cleaner itself does not have a large volume. And the engine response can be improved.

2) The air cleaner and the intake chamber are divided to have a volume, and the two are allocated to the left and right sides of the engine. Therefore, it is possible to prevent one of them from protruding greatly to the side of the vehicle body, and to inconvenience the appearance. can avoid.

3) Since the location of the air cleaner and the intake chamber is on the left and right sides of the engine and not between the cylinders, even when the angle of the V bank formed by the cylinder is small,
They can be arranged as having sufficient volume.

4) Since components requiring a large volume are not provided in the upper part of the engine (that is, between the cylinders),
The degree of protrusion upward from the engine is small, so that even when a fuel tank is provided above, it is not necessary to sacrifice the capacity of the tank.

The intake device according to the second aspect has the following effects. That is, 5) The carburetor can be provided very close to the cylinder, and the carburetor and the duct can be arranged by effectively utilizing the space between the valleys between the cylinders.

6) The cross section of the duct can be increased in the portion passing above the air cleaner and the intake resistance can be reduced.

[Brief description of the drawings]

FIG. 1A is an intake device 1 according to an embodiment of the present invention;
FIG. 2 is a side view (showing the V-type engine 3 with the intake chamber 14 removed). FIG. 1B is a front view of the intake device 10 (a sectional view taken along line bb in FIG. 1A).

FIG. 2 is a side view showing a main part of the motorcycle 1 equipped with the intake device 10 and the V-type engine 3 of FIG.

FIG. 3 is a side view of a main part of a motorcycle having a conventional intake device 10 ′.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 3 V-type engine 3A / 3B cylinder 4 Fuel tank 10 Intake device 12 Air cleaner 13 Duct 14 Intake chamber

Claims (2)

(57) [Claims] An intake device provided in a motorcycle having a V-type engine mounted with a cylinder inclined in front and rear of a vehicle body, wherein an air cleaner and an intake chamber connected to a downstream side thereof are divided into right and left sides of the engine. An intake device for a motorcycle, characterized in that the intake devices are disposed one by one, and the two are connected by a duct passing between the front and rear cylinders inclined as described above. 2. The above-mentioned duct is arranged so as to be inclined so as to connect an upper part of an air cleaner and a lower part of an intake chamber, and a carburetor is provided between the front and rear cylinders above a part of the duct close to the intake chamber. The intake device for a motorcycle according to claim 1, wherein