JP2003246287A - Fuel system structure for scooter-type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel system structure for a scooter-type vehicle which enables the prevention of air accumulation in a fuel tank even when fuel is supplied to the fuel tank with the vehicle parked using a side stand, and the easy arrangement of a breather pipe. <P>SOLUTION: The fuel system structure for the scooter-type vehicle has a main tank 17 as the fuel tank that is arranged on the body of the scooter-type vehicle having the side stand. The main tank 17 is arranged under a foot board and is inclined so that a side 17d on which the side stand is arranged and an upper face 17a that opposes the side 17d are made lower when a vehicle body is in a stand-up position. The upper surface 17a of the side 17d on which the side stand is arranged is provided with an air bleeding outlet 17b, and a refuel port is arranged in a position above the main tank 17 on the side of the side stand of the vehicle body, and the vicinity of the refuel port is connected to the air bleeding outlet 17 via the breather pipe. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel system structure for a scooter type vehicle having a side stand and a fuel tank.

[0002]

2. Description of the Related Art Conventionally, a scooter type vehicle is provided with a head pipe of a vehicle body frame at a front portion of a vehicle body, and a steering shaft is rotatably inserted through the head pipe.
There is a vehicle body in which the head pipe is provided, in which a fuel supply port for supplying fuel to a fuel tank is provided, and the fuel tank is provided below the footboard.
Then, the fuel is supplied to the fuel tank by the fuel gun from the fuel filler port.

A breather pipe for venting air from the fuel tank is connected to the upper surface of the fuel tank (see Patent Document 1).

On the other hand, in such a scooter type vehicle,
As a part of environmental measures, the gasoline vaporized in the fuel tank is introduced together with air into the canister via the charge hose, the gasoline and air are separated in the canister, and only the gasoline is introduced from the canister into the carburetor via the purge hose to form a mixture. Offering is done.

By the way, a scooter adopting a construction in which a main tank (fuel tank) is arranged below the footboard, a sub tank is arranged above the foot board in a portion surrounded by a leg shield, and both tanks are connected by a fuel hose. In a model vehicle, the canister was placed near the sub tank.

[0006]

[Patent Document 1] Japanese Utility Model Laid-Open No. 62-112982.

[0007]

However, in such a conventional vehicle, when the fuel tank is refueled while the vehicle is parked using the side stand, the fuel tank is tilted. There is a risk that air will accumulate in the air, and that the accumulated air will blow out when the tank is full and that the oil level will change due to air expansion.

Therefore, in FIG. 4 of Patent Document 1, if an air vent is provided at the right end of the fuel tank, the fuel tank inside the fuel tank can be refueled even when the side stand provided on the left side of the drawing is used. Although it is possible to prevent air accumulation, it is not easy to arrange the breather pipe (reference numeral 17 in the figure). That is, when connecting to the fuel filler port on the opposite side of the vehicle body, if you pass it in the vehicle width direction at the bottom of the footboard, air can be created in the breather pipe, and you can use the down tube to pass in the vehicle width direction at the leg shield part. It is necessary to intersect with, and the space for placing feet (in front of the knee) will be narrowed at the intersection.

On the other hand, in the scooter type vehicle, when the canister is arranged in the vicinity of the sub tank as described above, the purge hose connecting the canister and the carburetor has a substantially U shape in a side view, and the inside of the purge hose is changed from the canister to the carburetor. The atomized gasoline flowing toward the tank is liquefied on the way and accumulates at the bottom of the purge hose. The accumulated gasoline blocks the purge hose, which causes a problem that the original function of the canister is not fully exerted.

Further, there is a restriction on the space of the portion surrounded by the leg shield below the steering wheel, and if the canister is arranged in this portion, the widthwise dimension of the scooter type vehicle is increased.

Therefore, according to the present invention, even when the fuel tank is refueled while the vehicle is parked using the side stand, it is possible to prevent air accumulation in the fuel tank and to easily arrange the breather pipe. An object is to provide a fuel system structure for a scooter type vehicle.

Another object is to allow the function of the canister to be sufficiently exerted stably and to make the vehicle body compact in the width direction.

[0013]

In order to achieve the above object, the present invention as set forth in claim 1, is a fuel system for a scooter type vehicle having a fuel tank arranged in a vehicle body of a scooter type vehicle having a side stand. In the structure, the fuel tank is disposed below the footboard, and in a state where the vehicle body is in an upright posture, the fuel tank is inclined so that an upper surface opposite to a side on which the side stand is disposed is lowered, and An air vent is provided on the upper surface on the side where the side stand is disposed, and a fuel filler is provided above the fuel tank and on the side of the vehicle body where the side stand is disposed, and in the vicinity of the fuel filler. The fuel system structure for a scooter type vehicle is characterized in that the air vent is connected by a breather pipe.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the inclination angle of the upper surface of the fuel tank is substantially horizontal when the vehicle body is tilted using the side stand. It is characterized in that it is set along the direction.

The invention according to claim 3 is the same as claim 1 or 2.
In addition to the configuration described in (1), the key cylinder is disposed on the side opposite to the side where the side stand is disposed with respect to the vehicle body.

The invention according to claim 4 is the invention according to claims 1 to 3.
In addition to the configuration according to any one of the above, the fuel vaporized in the fuel tank is guided together with air to a canister via a charge hose, the fuel and air are separated in the canister, and only the fuel is carbureted from the canister via a purge hose. And the canister is arranged at the lowermost part of the vehicle body.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the main tank, which is the fuel tank disposed below the footboard, and the sub-tank disposed above the main tank, are used as fuel. The connection is made with a hose, and the canister is arranged below the sub-tank and the carburetor.

The invention according to claim 6 is the invention according to claim 4 or 5.
In addition to the configuration described in (1), the canister is arranged near the lower end of a down tube extending obliquely downward from the head pipe toward the rear of the vehicle body.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on embodiments.

[First Embodiment of the Invention] FIGS. 1 to 10 show a first embodiment of the present invention.

First, the structure will be described. In the figure, reference numeral 11 is a vehicle body frame of a scooter type vehicle.
A head pipe 12 through which a steering shaft (not shown) is rotatably inserted is provided in the vehicle front part of the vehicle, and a main tube 13 is extended rearward and obliquely downward from the head pipe 12. A pair of down tubes 14 are arranged on the left and right of the main tube 13.

A main tank 17 as a "fuel tank" is supported on the vehicle body frame 11 below the footboard, and an upper surface 17a of the main tank 17 projects upward on the vehicle rear portion 17c side as shown in FIG. Along with
As shown in FIG. 8, in the state where the vehicle body is in the standing posture, the side 17d is inclined so that the side opposite to the side 17d (the left side 17d when viewed from the rear of the vehicle) is lower.

As shown in FIG. 9, the inclination angle of the upper surface 17a of the main tank is set so that when the vehicle body is tilted by using the side stand 36, the upper surface 17a is substantially horizontal.

The side stand 3 on the upper surface 17a
An air vent port 17b is provided on the side 17d on which 6 is disposed.

A refueling pipe 18 is extended upward from a front end 17e of a left side 17d of the upper surface 17a of the main tank 17 when viewed from the rear of the vehicle, and a sub tank 19 is disposed at an upper end of the refueling pipe 18. This sub tank 1
9. A fuel supply cylinder 20 is provided so as to project obliquely upward from 9 and the fuel supply cylinder 2
A fuel filler port 21 is formed at the upper end portion of 0, and a filler cap 22 that opens and closes the fuel filler port 21 is provided.

The fuel filler port 21 is arranged on the left side of the front portion of the vehicle body where the head pipe 12 of the vehicle body frame 11 is provided when viewed from the rear side of the vehicle body. The lower end portion 34a of the second breather pipe 34 is provided on the left side 17d of the upper surface 17a of the main tank 17 when viewed from the rear of the vehicle.
In addition to being connected to b, the upper end portion 34b of the second breather pipe 34 is connected to the oil supply cylinder 20. A key cylinder (not shown) is provided on the right side of the front of the vehicle body when viewed from the rear of the vehicle.

As shown in FIG. 10, the side stand 36 is disposed on the left side of the vehicle body, and the left side 17d of the main tank 17 as seen from the rear of the vehicle has the oil supply pipe 18 and the second side as described above. The breather pipe 34 is connected.

On the other hand, as shown in FIGS. 1 and 2, a mounting piece 19a is extended around the sub-tank 19, and the mounting piece 19a is screwed to a rectangular support pipe 24 fixed to the head pipe 12. It is fixed in.

A fuel receiving portion 26 for receiving the fuel that has spilled around the fuel filling opening 21 is disposed around the fuel filling opening 21, and the fuel receiving portion 26 is open at the upper side. It has an open rectangular box shape, and is adapted to be folded in the arrow direction from the state shown in FIG. 1 through the folding line portion 26a. At the time of refueling, the fuel receiving portion 26 is unfolded by opening the lid body provided on the leg shield 28, while the fuel receiving portion 26 is folded by closing the lid body.

An upper end portion 27a of a drain hose 27 for discharging the fuel accumulated in the fuel receiving portion 26 to the outside of the vehicle is connected to the bottom portion of the fuel receiving portion 26, and the drain hose 27 is located below (substantially directly below). The drain hose 27 is extended to discharge the fuel to the outside of the vehicle through the lower end opening 27b.

The lower end opening 27b of the drain hose 27
Is located above the under cover 29 that covers the lower side of the vehicle body, as shown in FIG.

The under cover 29 is formed with a discharge opening 29a for discharging the fuel flowing down from the lower end opening 27b of the drain hose 27 to the outside of the vehicle.
“A” is formed closer to the vehicle rear side than the position directly below the lower end opening 27b of the drain hose 27.

The upper surface portion 19b of the sub tank 19
Is connected to the upper end 30a of the first breather pipe 30 for adjusting the pressure in the main tank 17, and the lower end 30b of the first breather pipe 30 is connected to the lower end of the drain hose 27. As shown in FIG. 2 etc., it has a three-pronged shape.

Further, in the middle of the first breather pipe 30, there is provided a rollover valve 32 for preventing the fuel from being discharged to the outside when the vehicle falls.

Next, the case of refueling with the side stand 36 used will be described.

When the vehicle is parked using the side stand 36, the vehicle body leans toward the side stand 36, and the axis O leans to the left with respect to the vertical direction from the state shown in FIG. 8 as shown in FIG. Thereby, the upper surface 1 of the main tank 17
7a becomes substantially horizontal as shown in FIG.

From this state, when the filler cap 22 is removed and fuel is refueled from the refueling port 21 with a refueling gun (not shown), the air in the main tank 17 is replenished with air from the refueling pipe 18.
And it will come out outside through the 2nd breather pipe 34.

In this case, the upper surface 1 of the main tank 17
Since 7a is substantially horizontal as described above, it is possible to prevent air bubbles from being generated, and prevent blowout of the accumulated air when the tank is full and oil level fluctuation due to expansion of the air.

Although not shown, a main switch is usually provided on the right side of the front portion of the vehicle body, so that the fuel filler port 2
1 is disposed on the left side when viewed from the rear of the vehicle, thereby avoiding the main switch and refueling pipe 18 on the left side of the vehicle body.
Since the installation of the second breather pipe 34 and the second breather pipe 34 are completed, it is not necessary to route each pipe to the left and right of the vehicle body, and the installation can be easily performed in the shortest distance.

In the above embodiment, the sub tank 1
Although the present invention is applied to the one provided with 9, the present invention is not limited to this, and the present invention can be applied to the one provided with no sub-tank 19.

[Second Embodiment of the Invention] FIGS. 11 to 14
2 shows Embodiment 2 of the present invention.

FIG. 11 is a side view of the scooter type vehicle, and FIG.
FIG. 3 is a partial front sectional view of the front portion of the scooter type vehicle.

A head pipe 102 is located in the upper front part of the vehicle body of the scooter type vehicle 101 shown in FIG. 11, and a steering shaft 103 is rotatably inserted in the head pipe 102. And this steering shaft 103
A steering wheel 104 is attached to an upper end of the steering shaft 103, and a front fork 105 is connected to a lower end of the steering shaft 103. A front wheel 106 is rotatably supported on a lower end portion of the front fork 105.

A down tube 107 extends obliquely downward from the head pipe 102 toward the rear of the vehicle body, and then is bent and extends substantially horizontally toward the rear of the vehicle body. A pair of left and right backstays 108 branch off and extend obliquely upward toward the rear of the vehicle body.

By the way, the head pipe 1 at the front of the vehicle body
02, the down tube 107, etc. are covered with a front cover 109 made of resin.
The latter half of 9 constitutes a leg shield 110 also made of resin.

Further, a tandem type seat 111 is disposed behind the handle 104, and the seat 11
A low-floor footboard (foot rest) 112 is provided between the vehicle 1 and the handle 104. In the space below the footboard 112, a main tank 113 as a fuel tank similar to that of the first embodiment is arranged.

Further, behind the footboard 112 and below the seat 111, a unit swing type engine 114 as a power unit is provided.

The unit swing type engine 114 is arranged on the left side of the vehicle body, and this is the engine 1 as a drive source.
15 and a transmission case 116 including a V-belt type automatic transmission (not shown) and a speed reduction mechanism, which are integrally formed. The transmission case 116 extends from the left side of the vehicle body of the engine 115 to the rear side of the vehicle body, and the rear wheel is at the rear end thereof. 117 is rotatably supported. An air cleaner 118 is attached to the upper part of the transmission case 116.
An intake pipe 119 extending from 18 toward the front of the vehicle body is connected to the intake system of the engine 115, and a carburetor 120 is provided in the middle thereof.

The unit swing type engine 114 having the above construction is supported by an engine suspension bracket 121 fixed to the back stay 18 so as to be vertically swingable through a link mechanism 122, and its rear end is a rear wheel. 1
It is supported by the back stay 118 together with the rear cushion 123 through the rear cushion 123.

On the other hand, a portion of the vehicle body below the seat 111 is covered with a resinous vehicle body cover 124.
Above the unit swing type engine 114 inside the vehicle body cover 124, the storage box 12 having an upper surface opened.
5 is attached to the back stay 108 via front and rear attachment members 126 and a cross member 127, and arranged.
The storage box 125 extends over the entire length of the seat 111 to secure a large capacity, and as shown therein, a half-cap type helmet H1 and a full-face type helmet H2 can be stored at the same time. You can The sheet 1 is placed on the storage box 125.
11 is supported, and the front end of the seat 111 pivots up and down around a hinge 128 so that the storage box 1
Open and close 25. A cross member 129 is installed on the left and right back stays 108 in addition to the attachment member 126 and the cross member 127, and a grab bar 130 is attached to the attachment member 126 and the cross member 127.

By the way, in the scooter type vehicle 101 according to the present embodiment, as shown in FIG. 12, on the left side of the head pipe 102 in the space surrounded by the front cover 109 and the leg shield 110 at the front of the vehicle body. To
A small-capacity sub tank 131 is arranged, and the head pipe 10
A battery 132 is arranged on the right side of 2.

A flexible fuel hose 133 extending downward from the bottom of the sub tank 131 is connected to the large-capacity main tank 113 arranged below the foot board 112. Here, a fuel filler 134 is obliquely provided on the upper front side of the sub tank 131.
A detachable tank cap 135 is attached to the fuel filler port 134.
And a filler 136 around the fuel filler port 134.
Are provided so as to surround the fuel filler port 134.

The filler 136 receives gasoline, which is fuel that has overflowed from the fuel filler port at the time of refueling, and an overflow pipe 137 extends downward from the bottom of the filler pipe 136.
The lower end of is open to the atmosphere at the lower part of the vehicle body in front of the main tank 113.

A charge hose 138 extends downward from the upper portion of the sub tank 131. The charge hose 138 is diagonally arranged on the left side of the main tank 113 arranged near the lower end of the down tube 107. Is connected to the rear surface of the canister 139.

On the other hand, below the front of the seat 111,
A fuel pump 142 is attached to the cross member 129 via a stay (not shown) in the vicinity of the front end portion of the storage box 125 covered with the vehicle body cover 124. A negative pressure hose 143 extending from the intake system of the engine 115 is connected to the fuel pump 142. The fuel pump 142 is driven by the pulsation of intake pressure and sucks gasoline from the fuel tank 113 via the fuel hose 144. To raise the pressure of the fuel, and to feed this gasoline to the fuel hose 145
After that, it is supplied to the carburetor 120 to be used for forming an air-fuel mixture. Note that the air-fuel mixture formed in the carburetor 120 is the engine 11 of the unit swing type engine 114.
5 is supplied to combustion.

Details of the canister arrangement structure will be described with reference to FIGS. 13 and 14. 13 is a partial side view of the scooter type vehicle showing the canister arrangement structure, and FIG. 14 is a partial plan view of the same.

The canister 139 is a device for separating the vaporized gasoline introduced from the sub tank 131 through the charge hose 138 into gasoline and air.
As shown in FIG. 5, this is disposed obliquely so as to descend toward the front of the vehicle body on the lowermost portion of the vehicle body, that is, on the left side of the main tank 113 arranged near the lower end of the down tube 107 as described above.

The air hose 14 extending obliquely downward from the front surface of the canister 139 toward the front of the vehicle body.
0 is connected to the lower end of the overflow pipe 137, a purge hose 141 extending from the rear surface of the canister 139 extends obliquely upward in the vehicle body direction, and its end is connected to the carburetor 120.

The vaporized gasoline in the main tank 113 and the sub tank 131 is introduced from the upper portion of the sub tank 131 through the charge hose 138 into the canister 139 together with the air, and the canister 139 separates the gasoline and the air. Then, the separated gasoline is drawn by the negative pressure of the intake air, is supplied to the carburetor 120 through the purge hose 141 and is used for forming the air-fuel mixture, and the separated air is guided to the overflow pipe 137 through the air hose 140. , The overflow pipe 1
It is discharged into the atmosphere through the opening at the lower end of 37.

As described above, in the second embodiment,
Main tank 11 arranged below the footboard 112
3 and a sub-tank 131 arranged above this are connected by a fuel hose 133, and a canister 139
Is disposed at the lowermost portion of the vehicle body, that is, below the sub-tank 131 and the carburetor 120.
The lowermost part that causes a gasoline pool is not formed in the middle of the charge hose 138 and the purge hose 141 connected to the fuel cell 39, and therefore the charge hose 138 and the purge hose 141 are not blocked by the liquefied gasoline and the canister 139 Can stably exert its original function sufficiently.

Further, according to the second embodiment, the canister 139 is provided in the footboard 1 with a relatively large space.
Since it is arranged near the lower end of the down tube 107 below 12, the scooter type vehicle 101 can be made compact in the width direction.

[0062]

As described above, according to the first aspect of the present invention, the upper surface of the fuel tank on the side opposite to the side stand is lowered when the vehicle body is in the standing posture. In addition to the inclination, the air outlet is provided on the upper surface on the side stand side, so there is little air accumulation on the upper surface of the main tank when refueling. It is possible to suppress fluctuations in oil level due to blowout and expansion of air. Further, since the breather pipe connects the fuel filler port provided on the side where the side stand of the vehicle body is disposed and the air vent port provided on the same side as the fuel filler port, the breather pipe is connected to the footboard. It is possible to prevent air accumulation in the breather pipe without having to pass it in the vehicle width direction at the lower part, and it is not necessary to pass it in the vehicle width direction even in the leg shield part, so it does not intersect with the down tube and put on the foot ( (Before the knee) Does not narrow the space.

According to the second aspect of the present invention, the inclination angle of the upper surface of the fuel tank is set so that the upper surface is substantially horizontal when the vehicle body is tilted using the side stand. Generation of air pockets can be suppressed.

According to the third aspect of the invention, since the key cylinder is arranged on the side opposite to the side where the side stand is arranged with respect to the vehicle body, the oil supply pipe and the breather pipe are arranged on the side stand side. Since wiring of the key cylinder and the like are arranged on the opposite side, it is possible to easily route each pipe in the shortest distance.

According to the invention described in claim 4, the fuel vaporized in the fuel tank is introduced together with the air into the canister through the charge hose, the fuel and the air are separated in the canister, and only the fuel is passed from the canister through the purge hose. Since the canister is arranged at the lowermost part of the vehicle body by guiding it to the carburetor to form the air-fuel mixture, the canister function can be sufficiently exerted stably and the vehicle body can be made compact in the width direction. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a fuel receiving portion, a drain hose and the like according to a first embodiment of the present invention.

FIG. 2 is a front view of FIG. 1 according to the first embodiment as viewed from the front of the vehicle.

FIG. 3 is a rear view of FIG. 1 according to the first embodiment as viewed from the rear of the vehicle.

FIG. 4 is a plan view of FIG. 1 according to the first embodiment.

FIG. 5 is a plan view of the main tank according to the first embodiment.

FIG. 6 is a side view of the main tank according to the first embodiment.

FIG. 7 is a front view of the main tank according to the first embodiment as seen from the front of the vehicle.

FIG. 8 is a rear view of the main tank according to the first embodiment as viewed from the rear of the vehicle.

FIG. 9 is a rear view corresponding to FIG. 8 showing a tilted state of the main tank according to the first embodiment.

FIG. 10 is a side view of the vehicle rear side showing the side stand according to the first embodiment.

FIG. 11 is a side view of the scooter type vehicle according to the second embodiment of the present invention.

FIG. 12 is a partial front sectional view of the scooter type vehicle according to the second embodiment.

FIG. 13 is a partial side view of a scooter type vehicle showing a canister arrangement structure according to the second embodiment.

FIG. 14 is a partial plan view of a scooter type vehicle showing a canister arrangement structure according to the second embodiment.

[Explanation of symbols]

11 Body frame 12 head pipe 17 Main tank (fuel tank) 17a top surface 17b Air vent 17d side stand side 18 Refueling pipe 19 Sub tank 21 Filling port 34 Second Breather Pipe 36 side stand 101 scooter type vehicle 102 head pipe 107 down tube 110 leg shield 112 footboard 113 Main tank (fuel tank) 120 carburetor 131 sub tank 133 Fuel hose 138 Charge hose 140 air hose 141 Purge hose

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 37/00 301 F02M 37/00 301F 301G 301M 301P

Claims (6)

[Claims] 1. A fuel system structure for a scooter type vehicle including a fuel tank arranged in a vehicle body of a scooter type vehicle having a side stand, wherein the fuel tank is arranged below a footboard, and the vehicle body stands upright. In the posture, the upper surface on the side on which the side stand is installed is inclined so that the upper surface on the side opposite to the side on which the side stand is installed is lowered, and
An air vent is provided, and a fuel filler is provided above the fuel tank and on the side of the vehicle body where the side stand is disposed, and the vicinity of the fuel filler and the air vent are connected by a breather pipe. A fuel system structure for a scooter type vehicle characterized by the above. 2. The tilt angle of the upper surface of the fuel tank is set so that the upper surface is substantially horizontal when the vehicle body is tilted using the side stand. The fuel system structure for the scooter type vehicle according to 1. 3. The fuel system structure for a scooter type vehicle according to claim 1, wherein a key cylinder is arranged on the side opposite to the side on which the side stand is arranged with respect to the vehicle body. 4. The fuel vaporized in the fuel tank is led to a canister together with air through a charge hose,
The fuel can be separated from the air in the canister, and only the fuel is guided from the canister to a carburetor through a purge hose to be used for forming a mixture, and the canister is arranged at the bottom of the vehicle body. 2. A fuel system structure for a scooter type vehicle according to any one of 1. 5. A main hose, which is the fuel tank arranged below the footboard, and a sub tank arranged above the main tank are connected by a fuel hose, and the canister is arranged below the sub tank and the carburetor. The fuel system structure for a scooter type vehicle according to claim 4, wherein 6. The fuel system for a scooter type vehicle according to claim 4, wherein the canister is arranged in the vicinity of a lower end of a down tube extending obliquely downward from the head pipe toward the rear of the vehicle body. Construction.