JP3308364B2 - Air intake system for motorcycles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for supplying an air-fuel mixture to an engine, and to a motorcycle intake device having an intake air box disposed above the fuel supply device.

[0002]

2. Description of the Related Art Such an air intake device is known. For example, as described in Japanese Utility Model Laid-Open Publication No. 4-45193, a main frame provided in a left-right pair in the front-rear direction of a vehicle body is provided with a main frame. A fuel tank supported on the main frame, an intake air box disposed below the fuel tank,
A fuel supply device having a throttle valve connected to the intake air box and disposed below and in the space between the left and right main frames, and pressurizing the intake air with a ram pressure generated by traveling wind, The capacity of the intake air box was increased as much as possible to improve the output.

[0003]

Incidentally, there are a type of air box for intake which is simply mounted on a fuel supply device, and a type in which a lower portion surrounds the periphery of the fuel supply device. In the case of the former structure, if the capacity of the intake air box is increased in order to increase the output, the intake air box will be extended upward, and the vehicle height will increase accordingly, and the fuel tank There is a problem that the capacity is also limited.

On the other hand, according to the latter structure, pressure loss occurs due to poor alignment with peripheral parts, such as difficulty in sealing due to the operation wire for the throttle valve penetrating through the lower portion, and accompanying this alignment. Problems such as reduced workability. Therefore, an object of the present invention is to solve such a problem.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, a motorcycle air intake system according to the present invention comprises a main frame provided in a left-right pair in the front-rear direction of a vehicle body, and a main frame provided on the main frame. And a throttle valve connected to the intake air box and disposed below and in the space between the left and right main frames. A fuel supply device, and a lower extension on the left and right of the lower portion of the intake air box, which extends around the inside of each main frame and the left and right side surfaces of the fuel supply device and increases the capacity of the intake air box. It is characterized by being provided integrally.

The fuel supply device can use a carburetor or a throttle body of an electronic fuel injection device, and the intake air box is a simple air tank without an ordinary air cleaner box or air purifying function. You may.

[0007]

When the intake air box is attached to the fuel supply device, the lower extension formed at the lower portion of the intake air box goes around the left and right side surfaces of the fuel supply device. For this reason, since the capacity of the downward extension increases, it is possible to secure a sufficient capacity without extending the intake air box upward, and the downward extension is formed by the left and right side surfaces of the fuel supply device. And the corresponding main frame extends into the space between the main frame and the corresponding main frame, so that the space in this portion can be effectively used.

Further, since the downward extension is provided on the left and right sides of the fuel supply device, peripheral parts, for example, an operating wire for a throttle valve do not have to penetrate through the lower front side of the intake air box. In addition, the risk of poor alignment with peripheral components, such as difficulty in sealing, is reduced.

[0009]

According to the present invention, the downwardly extending portion is formed at the lower portion of the intake air box and is wrapped around the left and right side surfaces of the fuel supply device, so that the capacity of the downwardly extending portion is increased. It is possible to secure a sufficient capacity without extending the box upward, it is possible to improve the output, and the lower extension portion, the left and right side of the fuel supply device,
Since it extends into the space between the corresponding main frames, the space of this portion can be used effectively, and the operating wire for the throttle valve does not have to penetrate the lower part of the intake air box, so that This eliminates the need for a seal at the penetrating portion, and simplifies the work of aligning with peripheral parts. This prevents output loss due to pressure loss due to poor alignment and improves workability when installing an air box for intake. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a lateral cross-sectional view conceptually showing an arrangement state of an intake device, FIG. 2 is a side view of a motorcycle to which the present embodiment is applied, FIG. 3 is an enlarged side view of the intake device, and FIG. Is a plan view of the intake device with the cover removed, and FIG. 5 is a front view of the intake air box with a base portion partially cut away and shown.

First, in FIG. 2, a windshield 1 is attached so as to continuously cover the front of the vehicle body from the upper front of the inverted front fork 2 to the left and right sides of the front and rear four-cylinder V-type four-cylinder engine 3. The engine 3 is supported below a main frame 4 extending in the front-rear direction in a left-right pair. A throttle body 5 is attached to a V-bank portion of the engine 3, and outside air is supplied from an intake air box 6 above the throttle body 5. I have. The throttle body 5 corresponds to the fuel supply device of the present invention.

An air box 6 for intake is provided with a main frame 4.
Outside air is supplied from a wind guide pipe 8 which is accommodated in a recess provided at the bottom of the fuel tank 7 supported above and penetrates the front part of the fuel tank 7 vertically. The wind guide pipe 8 is connected to a wind guide port 10 opened at the front of the windshield 1 by an outside air introduction pipe 9. The air guide opening 10 opens forward, and a wind guide path 11 is formed in a concave groove shape on the surface of the windshield 1 in front of the air guide opening.

The outside air introduction pipe 9 is formed integrally with the windshield 1, separately from the windshield 1, or formed by a suitable method such as a front-rear splitting method. Since the filter adjusts the amount of outside air introduced into the outside air introduction pipe 9, the degree of coarseness and the like can be arbitrarily selected.

The outside air that has entered the outside air introduction pipe 9 from the air guide path 11 through the air guide port 10 passes through the air guide pipe 8 and exits into the space formed below the bottom 12 of the fuel tank 7. ,
The air enters the intake air box 6 through an intake duct (not shown) formed on the front surface of the intake air box 6, and further from each intake port of the throttle body 5 for each of the left and right cylinders of the front and rear banks 13 and 14. (Described later), and is supplied to each cylinder as an air-fuel mixture in the throttle body 5.

1 and 3, the intake air box 6 includes a cover 20 and a base 21 whose opening is covered by the cover 20, and the base 21 is mounted on the throttle body 5. A downwardly extending portion 22 extending downward is integrally formed on the lower left and right sides of the lower portion, contributing to an increase in the capacity of the base 21.

By increasing the capacity, a sufficient capacity in the intake air box 6 can be ensured, so that the vertical width of the intake air box 6 can be made relatively small, and the fuel tank 7 projecting upward by that amount. Has a large capacity at the front end. Further, since the downward extension portion 22 extends into the space 15 (FIG. 1) between the left and right side surfaces of the throttle body 5 and the corresponding main frames 4, the space 15 of this portion can be effectively used. And is protected by each main frame 4.

As apparent from FIGS. 1 and 5, the base 2
On the left side of the bottom of the upper part 1, an upper bottom part 23 rising upward is formed so as to extend long in the front-rear direction. I have. The groove-shaped space 24 is opened downward and forward and backward, through which operation wires 31 and 32 for opening and closing the throttle valve 30 (FIG. 4) are passed.

As is apparent from FIGS. 3 and 4, the operation wire 31 is a return side, and the operation wire 32 is a pull side.
A midway is supported by a guide 33 provided on the left side surface of the throttle body 5, and each end is connected to a drum 34. The rotation of the drum 34 causes the link 35 (FIG. 3)
The throttle valves 30 provided for the front, rear, left and right cylinders are interlocked with each other. Drum 3
4 is exposed to the outside from the concave portion 25 provided in the downward extension portion 22 to facilitate maintenance.

As is apparent from FIG. 4, a seat plate 37 is mounted on the throttle body 5 with screws 38 around the intake port 36 of the throttle body 5. The seat plate 37 is also provided with a screw hole 39 for bolting the base 21. On the other hand, the bottom of the base 21 is provided with a communication hole 26 into which the intake port 36 of the throttle body 5 is fitted, and a bolt mounting hole 27 penetrating in the vicinity thereof (only the intake port 36 at the lower left in the figure is shown). Have been. This mounting hole 2
Reference numeral 7 designates the base 21 mounted on the throttle body 5 so as to be aligned with the screw hole 39 of the seat plate 37. In this state, a bolt 28 is passed through the mounting hole 27 and fastened to the screw portion 37. 21 can be mounted on the throttle body 5 only by fastening work from above.

In FIG. 2, reference numeral 40 denotes a front wheel, 41 denotes a seat,
42 is a rear cover, 43 is a cantilevered rear arm, 44 is a rear wheel, 45 is an exhaust pipe, and 46 is a rear cushion unit. The rear cushion unit 46 is disposed vertically, and has an upper end supported by the rear end of the main frame 4 and a lower end supported by the cantilevered rear arm 43.

FIG. 6 is a side view of the rear cushion unit 46, and FIG. 7 is a plan view of the rear cushion unit 46. As is apparent from these figures, the upper portion of the rear cushion unit 46 is provided with a heat guard 47. . Heat guard 47
Is an arc-shaped portion 51 which is attached to a mounting boss 49 integrally formed with an upper mounting bracket 48 of the rear cushion unit 46 by a bolt 50, and covers an upper portion of the rear cushion unit by about 周 circumference, and a linear portion extending tangentially. 52,
The rear cushion unit 46 is disposed between the exhaust pipe 45 and the exhaust pipe 45 to block the heat of the exhaust pipe 45 to prevent the oil temperature in the oil chamber 53 of the rear cushion unit 46 from rising.

When the heat guard 47 is provided, the conventional heat guard is a cylindrical member coaxial with the rear cushion unit 46 supported between the spring 54 and the spring seat 55 of the rear cushion unit 46, so that it is difficult to remove. In addition, there were many restrictions on mounting locations and shapes. However, as in this embodiment, the heat guard 4
Providing 7 facilitates removal, and significantly increases the degree of freedom of the mounting location and shape. Reference numeral 56 denotes a lower spring seat.

Next, the operation of this embodiment will be described. First,
In order to mount the intake air box 6, as shown in FIG. 4, the base 21 is previously placed on the throttle body 5 to which the seat plate 37 is mounted, and can be mounted by bolts 28 only from above. For this reason, compared with the conventional intake air box of the type surrounding the throttle body 5, the base 21 can be divided into upper and lower parts at the throttle body 5 part, so that the base 21 can be a single member, so that the mounting work is remarkably performed. It became easier.

The lower extending portion 22 includes left and right side surfaces of the throttle body 5 and corresponding main frames 4.
Since the base 21 is increased in capacity using this space 15, the capacity in the intake air box 6 can be secured to a sufficient size. It is not necessary to extend the entire box 6 upward, so that the bottom 12 of the fuel tank 7 above it
Of the fuel tank 7 can be increased, and the overall vehicle height does not need to be increased. Moreover, the output can be improved by a sufficient capacity of the intake air box 6. In addition, the space 15 can be effectively used, and the lower extension 22 can be protected by each main frame 4.

Further, since the downwardly extending portions 22 are provided on the left and right and are not provided on the front and rear in this embodiment, the groove-like space 24 formed at the bottom of the base 21 inside the downwardly extending portions 22 is provided with a throttle valve. 30, an operation wire 31,
32, and can be passed through the lower portion of the base 21 without penetrating as conventionally used. For this reason, the seal required for the penetrating portions of the operation wires 31 and 32 can be eliminated, and there is no danger that a pressure loss occurs due to poor alignment of the seal and a situation that causes a decrease in output occurs, and Workability can be improved.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and applications are possible. For example, a carburetor may be used instead of the throttle body 5 as a fuel supply device. When the peripheral parts that need to be combined with the intake air box 6 include, in addition to the operation wires 31 and 32, various pipes arranged on the bottom side of the intake air box 6 as necessary. There is.

[Brief description of the drawings]

FIG. 1 is a sectional view conceptually illustrating an embodiment.

FIG. 2 is a side view of the motorcycle to which the embodiment is applied;

FIG. 3 is an enlarged side view of a main part of the embodiment.

FIG. 4 is an enlarged plan view of a main part of the embodiment.

FIG. 5 is a diagram showing a main part of the embodiment from the front.

FIG. 6 is a side view of a rear cushion unit of the motorcycle to which the embodiment is applied.

FIG. 7 is a plan view thereof.

[Explanation of symbols]

3: engine, 4: main frame, 5: throttle body (fuel supply device), 6: air cleaner (intake air box), 7: fuel tank, 20: cover, 21: base, 22: downward extension, 24 : Groove space, 31.3
2: Operation wire, 34: Drum

Continuation of front page (56) References JP-A-62-83292 (JP, A) JP-A-6-239279 (JP, A) JP-A-60-71333 (JP, A) JP-A-4-306184 (JP) , A) Japanese Utility Model Hei 4-45193 (JP, U) Japanese Utility Model Application Showa 60-103020 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02M 35/16 F02M 35/10 F02M 35/04 B62J 39/00 B62M 7/02

Claims (1)

(57) [Claims] 1. A main frame provided as a left-right pair in a front-rear direction of a vehicle body, a fuel tank supported on the main frame, an intake air box disposed below the main tank, and an intake air A fuel supply device having a throttle valve connected to the box and disposed below and in the space between the left and right main frames. A suction unit for a motorcycle, which is integrally provided with a downwardly extending portion that goes inside each main frame and outside the left and right side surfaces of the fuel supply device and increases the capacity of the air box for suction.