JP2893699B2 - Air bleeding structure of motorcycle intake system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air bleeding structure for a motorcycle air intake system, and more particularly, to connecting an air cleaner to a downdraft carburetor and connecting the air cleaner to a fuel tank or a tank cover ( (Hereinafter referred to as fuel tank, etc.)
The present invention relates to an improvement in an arrangement structure of an air release hose which is not affected by dynamic pressure, does not cause liquefied fuel to flow out, and does not hinder the mounting work of a fuel tank or the like.

[Conventional technology]

2. Description of the Related Art Conventionally, an air vent hose for introducing atmospheric pressure into a float chamber of a vaporizer is connected to a vaporizer of a motorcycle intake device. Since this air release hose needs to be led out and opened at a position where it is not affected by the dynamic pressure of the traveling wind, conventionally, for example, the air release hose is extended to the rear of the crankcase and There is one that is made to open. However, in the case of this structure, although it is not affected by the dynamic pressure, there is a possibility that the air release hose may be blocked by rainwater or the like from which the rear wheel has jumped up, so that sufficient consideration must be given to the selection of the opening position.

Therefore, as an air bleeding structure capable of avoiding the possibility of such blockage due to rainwater or the like, conventionally, there is a structure in which the air bleeding hose is opened at a rear wall portion of a cylinder and above a crankcase. However, in this case, when the fuel vaporized in the air release hose is liquefied, it may fall on the crankcase or the like, and may stain the surroundings.

Therefore, in order to solve all the problems of the above-mentioned effects of dynamic pressure, blockage due to rainwater, drop of liquefied fuel, etc., the air bleeding hose is extended to the vicinity of the air cleaner connected to the upper side of the vaporizer and opened at this upper position. It is possible.

[Problems to be solved by the invention]

By the way, when a downdraft type carburetor is employed and an air cleaner is disposed above the carburetor, it is common to cover the periphery of the air cleaner with a fuel tank or a tank cover. In such a case, if the above-described air bleeding hose is extended to near the air cleaner, the air bleeding hose interferes with the wall surface of the fuel tank or the like when the fuel tank or the like is mounted, and the mounting work of the tank or the like becomes difficult. There is a concern that may occur. Further, when the bleeding hose is made of a flammable hose, it may be bent or closed due to interference with a fuel tank or the like.

Therefore, the present invention has been made to solve the above-mentioned conventional problems and the above-mentioned concerns, and does not cause the effects of dynamic pressure, blockage due to rainwater, etc., and the problem of falling of liquefied fuel. It is an object of the present invention to provide an air bleeding structure for a motorcycle intake device that does not hinder mounting work.

[Means for solving the problem]

According to the present invention, a downdraft type carburetor is connected to an engine, an air cleaner is connected to the carburetor so as to cover an upper portion thereof, and at least a rear portion of the air cleaner is a fuel tank or a tank cover (hereinafter referred to as a fuel tank or the like). ), The air cleaner has an upper and lower two-part structure composed of an upper case and a lower case, and the flange portions of the upper and lower cases are detachably connected to each other. And a structure in which an element is sandwiched between the flange portions, one end of which is connected to the vaporizer, and the other end of at least two air release hoses for introducing atmospheric pressure into a float chamber of the vaporizer. The outer sides of the lower and upper rear walls in the vehicle width direction are extended so as to rise up to the vicinity of the upper end, and the extended portions are lowered so as to pass through the central portion in the vehicle width direction. The air vent hose is bent, and the bending start point and the bending end point of the extension portion of the air release hose are engaged with notches formed so as to face each other with a bracket portion integrally formed with the flange portion of the lower rear wall. And the front end opening of the extension portion is formed in the space between the upper and lower rear walls of the air cleaner and the bottom wall such as the fuel tank and in the vehicle width direction of the upper and lower rear walls. It is characterized by being located at substantially the center in the vertical direction.

[Action]

According to the air release structure according to the present invention, the space between the rear wall of the air cleaner and the wall surface of the fuel tank or the like where the traveling wind hardly hits, and the substantially central portion of the rear wall of the air cleaner in the vehicle width direction and the vertical direction. Because the air release hose is open, the rising portion of the air release hose itself has the effect of preventing the traveling wind from being caught, so it is difficult for the traveling wind to get caught, and therefore it is hardly affected by the dynamic pressure. It is not affected by rainwater. Further, since the air release hose is opened at a position higher than the vaporizer, a sufficient head difference (water head difference) can be obtained. Therefore, the liquefied fuel is returned to the float chamber, so that the liquefied fuel does not flow out of the air release hose, and the above-described problem of contamination can be prevented.

Furthermore, in the present invention, the air release hose is fixed to the wall surface of the air cleaner, so that the air release hose does not hinder the work of mounting the fuel tank, etc., and therefore, the mounting workability is deteriorated by the air release hose. There is no.

Also, when fixing the extension of the air release hose to the air cleaner, it was fixed to the bracket part formed on the flange part of the lower case of the upper and lower two parts. The upper case can be detached independently while the air cleaner is fixed to the lower case, and maintenance is not deteriorated by fixing the air release hose to the air cleaner.

Furthermore, in fixing the air bleeding hose, the bending start point and the bending end point of the extension of the air bleeding hose are engaged with the notch formed so as to face the bracket portion of the lower case. The air release hose can be fixed to the lower case by a simple operation. Further, since the bracket portion can be integrally formed at the time of resin molding of the lower case, there is no problem of cost increase.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 5 are views for explaining an air bleeding structure of a motorcycle intake device according to one embodiment of the present invention.

In the figure, reference numeral 1 denotes a motorcycle to which the present embodiment is applied. A body frame 2 of the motorcycle 1 has a head pipe 2a connected to a pair of left and right main pipes 2b, 2b extending diagonally downward and rearward of the vehicle. A rear arm bracket 2c is connected to the rear end of each main pipe 2b, and the left and right rear arm brackets 2c are connected to each other by a cross pipe (not shown). The main pipe 2b is a rectangular tube formed by welding a pair of U-shaped aluminum plates in the middle and welding them together.The cross-sectional shape of the main pipe 2b is longer and rectangular toward the head pipe 2a. The left and right main pipes 2b surround both sides of the upper part of the vehicle.

A front fork 4 that pivotally supports the front wheel 3 at the lower end is pivotally supported left and right by the head pipe 2a. A steering handle 5 is fixed to the upper end of the front fork 4. I have. Also, with the above rear arm bracket 2c,
At the rear end, a front end of a rear arm 7 that pivotally supports the rear wheel 6 is pivotally supported vertically swingably.

A fuel tank 8 is mounted on the left and right main pipes 2b of the body frame 2 so as to cover between the two pipes. The front half of the bottom wall 8a of the fuel tank 8 is raised upward, and the bottom wall 8a and the left and right side walls 8b form an air cleaner arrangement space A. A saddle-shaped seat 9 is mounted behind the fuel tank 8, and a lower portion of the seat 9 is surrounded by a rear cover 10. The rear cover 10 covers above the rear wheel 6.

An engine unit 11 is suspended and supported below the body frame 2. The engine unit 11 is a water-cooled 4-cycle parallel 4-cylinder engine in which a cylinder body 13a, a cylinder head 13b, and a head cover 13c are stacked on an upper wall of a crankcase 12 containing a crankshaft and a transmission. The main body 13 is configured so as to be connected to a substantially forward inclined state of about 45 degrees. Also, on the left of the engine unit 11,
The right and the front of the vehicle are covered with a cowling 21. The cowling 21 includes a screen 21a, an upper cover 21b that covers the front side of the front fork 4, and a pair of side covers that cover the left and right sides of the engine unit 11. 21c. On the left and right sides of the front cover 21b, running air inlets 22 are formed, and inside the inlets 22, a front end of an inlet duct 23 is connected. This introduction duct
The rear end of the pipe 23 penetrates the front of the main pipe 2b and opens into the air cleaner arrangement space A.

An independent carburetor 14 for each cylinder is connected to a rear wall of the cylinder head 13b via a cab joint 14a. Each of the carburetors 14 is a so-called downdraft type carburetor in which the air flow goes from top to bottom, and an air cleaner 15 is connected to a suction port 14c of the carburetor 14 via a cleaner joint 14b. The air cleaner 15 is located in the air cleaner arrangement space A, and the top wall, the rear wall, and the left and right side walls are provided with the fuel tank 8 described above.
Are covered with a bottom wall 8a, a side wall 8b and the left and right main pipes 2b.

The air cleaner 15 includes an upper case 16 and a lower case 17.
The upper and lower flanges 16d, 17
In the cleaner case that is detachably bolted with k,
It has a structure in which the element 18 is provided. Brackets 17g and 17f are formed integrally with the flange 17k of the lower case 17, and the brackets 17g and 17f have cutouts 17i and 17j.
Are formed to oppose each other. A projection 17h formed on the side wall of the lower case 17 is fixed to the main pipe 2b via a grommet 21d. The element 18 is formed in a rectangular plate shape, and its holding bracket 18a
Are sandwiched between the flange portions of the upper and lower cases 16 and 17. And the front side wall 16 of the upper case 16
An upper passage 16b is formed integrally with a so as to extend downward, and the upper passage 16b is connected to a lower passage 17b formed integrally with a front wall 17a of the lower case 17. The lower half of the front side wall 17a is retracted rearward to form a guide wall 17c, and the lower side passage 17b further includes a suction duct 1c.
9 is connected. The suction duct 19 extends toward the guide wall 17c along the lower surface of the receding wall of the front side wall 17a, and is fixed to the lower case 17 by bolts. Further, the suction duct 19 is opened so as to face the guide wall 17c, and the opening is located above the vaporizer 14. Thus, the traveling wind is received by the guide wall 17c and guided to the opening of the suction duct 19.

Near the suction port 14c of the vaporizer 14, one end 20a of an air release hose 20 for introducing atmospheric pressure into the float chamber 14d of the vaporizer is connected. The air release hose 20 is formed of a rubber tube and extends upward along both outer sides of the rear walls 17e and 16c of the lower case 17 and the upper case 16, and the extended portion 20c is provided near the upper end of the air cleaner 15 to close the vehicle. It is curved downward so as to pass through the center in the width direction. The bending start point and the bending end point of the extension portion 20c are set in the bracket portions 17g and 17f, respectively, by the notches 17i and 1c.
It is fixed by engaging with 7j. The upper end opening 20b of the extension 20c is connected to the upper and lower rear walls 16c, 17e.
Of the vehicle in the vehicle width direction and the vertical direction.

 Next, the operation and effect of this embodiment will be described.

According to the air intake device of the present embodiment, outside air such as traveling wind is introduced from the inlet 22 and passes through the inlet duct 23, and the above-described left,
It is introduced into the space A surrounded by the right main pipe 2b, the bottom wall 8a of the fuel tank 8, and the side wall 8b. The introduced air is guided by the guide wall 17c of the air cleaner 15 near the opening of the suction duct 19, is sucked from the opening, passes through the lower and upper passages 17b, 16b, is filtered by the element 18, and is then sucked into the vaporizer 14. Is done.

Further, an air release hose 20 is connected to the float chamber 14d of the vaporizer 14, and the atmospheric pressure is introduced into the float chamber 14d by the hose 20, and the float chamber 14d is maintained at the atmospheric pressure. Become. When such an air release hose is installed, it is necessary to open the hose at a position that is not affected by the dynamic pressure of the traveling wind in order to maintain the float chamber of the vaporizer at atmospheric pressure without fluctuation. In this embodiment, the air release hose 20 is connected to the air cleaner 15 and the bottom wall of the fuel tank 8.
8b, and at the approximate center of the rear wall of the air cleaner 15 in the vehicle width direction and the vertical direction, so that the air release hose itself was used to prevent the traveling wind from being entrained.
Since there is almost no entanglement of the traveling wind, there is no influence from the dynamic pressure. Further, rainwater or the like hardly enters the space, and therefore, there is no problem that the air release hose 20 is blocked by the rainwater or the like. Furthermore, the air release hose 20 of the present embodiment extends upward from the connection port of the vaporizer 14 and has a large head difference. Therefore, even when the fuel vaporized from the vaporizer 14 is liquefied in the hose 20, The liquefied fuel is returned to the float chamber 14d and does not drip from the air release hose 20.

In this embodiment, since the air release hose 20 is fixed to the rear wall 17e of the air cleaner 15, for example, when the fuel tank 8 is mounted, the bottom wall 8a or the side wall 8b of the fuel tank 8 is connected to the air release hose. There is almost no interference with the mounting 20, so that the mounting operation can be performed easily and reliably. Further, although the air release hose 20 is made of a rubber tube, it hardly interferes with the fuel tank 8 or the like, and therefore does not block due to bending.

Connect the extension 20c of the air release hose 20 to the air cleaner 15
Brackets 17f and 17g formed on the flange 17k of the lower case 17 of the upper and lower two parts when fixing to
During maintenance such as cleaning of the element 18, the upper case 16 can be removed independently while the air release hose 20 is fixed to the lower case, and the air release hose 20 is fixed to the air cleaner 15. Therefore, the maintainability does not deteriorate.

Furthermore, when fixing the air release hose 20, the notch 17i, 17j formed to face the bracket portion 17g, 17h of the lower case 17 has a bending start point and a bending end point of the extension 20c of the air release hose 20. The air release hose can be securely fixed to the lower case by a simple operation. Further, since the bracket portions 17g and 17f can be integrally formed at the time of resin molding of the lower case 17, there is no problem of cost increase.

Also, a suction duct to the air cleaner 15 of the present embodiment.
19 is open toward the guide wall 17c of the air cleaner 15, and since the opening is located near the carburetor 14,
The suction air is not affected by the dynamic pressure, and furthermore, rainwater or the like does not enter.

〔The invention's effect〕

As described above, the other end opening of the air bleeding hose of the motorcycle air intake system according to the present invention is defined as the space between the rear wall of the air cleaner and the bottom wall of the fuel tank and the like, and the vehicle width of the rear wall. The extension of the air bleeding hose is located approximately at the center in the vertical and vertical directions, and the outer wall of the rear wall is formed so that both outer sides in the vehicle width direction of the rear wall rise up to near the upper end, and then are curved downward so as to pass through the central portion. When the extension of the air release hose is fixed to the air cleaner, it is fixed to the bracket formed on the flange portion of the lower case of the upper and lower parts. When fixing the air release hose, the bracket of the lower case is fixed. The bending start point and the bending end point of the extension of the air release hose are engaged with the notch formed so as to face the air, so that there is almost no entanglement of the running wind and the influence of the dynamic pressure is the most. Kuku, also can improve the maintainability such as cleaning elements, there is an effect that can be further securely fixed to the lower case of the air vent hose with a simple operation.

[Brief description of the drawings]

1 to 5 are views for explaining an air bleeding structure of a motorcycle air intake system according to one embodiment of the present invention. FIG. 1 is a sectional side view thereof, and FIG. 2 is a rear view of an air cleaner. FIG. 3 is a plan view, FIG. 4 is a left side view of the motorcycle to which the present embodiment is applied, and FIG. 5 is a plan view thereof. In the figure, 1 is a motorcycle, 8 is a fuel tank, 13b is a cylinder header (engine), 14 is a carburetor, 14d is a float chamber, 15 is an air cleaner, 17e and 16c are rear walls of an air cleaner, and 20 is an air release hose. is there.

Claims (1)

(57) [Claims] A downdraft type carburetor is connected to an engine, an air cleaner is connected to the carburetor so as to cover an upper portion thereof, and at least a rear of the air cleaner is connected to a fuel tank or a tank cover (hereinafter referred to as a fuel tank or the like). In the air release structure of the motorcycle air intake device covered by the following description, the air cleaner has an upper and lower two-part structure composed of an upper case and a lower case, and the upper and lower case flange portions are detachably connected to each other. At the same time, one end is connected to the vaporizer, and the other end of at least two air release hoses for introducing atmospheric pressure into the float chamber of the vaporizer is connected to the flange. Extend both sides of the lower and upper rear walls of the air cleaner in the vehicle width direction so as to rise up to the vicinity of the upper end, and lower the extended portion so as to pass through the center in the vehicle width direction. And a bending start point and a bending end point of the extension portion of the air release hose are engaged with notches formed so as to face each other with a bracket portion integrally formed on the flange portion of the lower rear wall. And the front end openings of the extension portions are formed in the space between the upper and lower rear walls of the air cleaner and the bottom wall of the fuel tank and the like and in the vehicle width direction of the upper and lower rear walls. And an air bleeding structure for a motorcycle air intake system, wherein the air bleeding structure is located substantially at the center in the vertical direction.