Fuel tank for motor vehicles

A fuel tank for motor vehicles of the type in which the rider rides the vehicle astride. A fuel cock is embedded in a concave portion formed in a body wall of the fuel tank, and a fuel suction pipe extends from the fuel cock into the tank, while a fuel pipe extends to the engine side located at the exterior of the tank. The fuel suction pipe and the fuel pipe can be brought into communication and out of communication with each other within the fuel cock. The position where the fuel cock is embedded in the body wall of the fuel tank may be at the upper surface of the tank, or alternatively it may be at a rear side of the tank. Such arrangement can afford an extremely good operability of the fuel cock while the rider sits astride the vehicle body, and permits an easy confirmation of the operating knob switching position.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a fuel tank for motor vehicles and more 
particularly to a structure of a fuel cock in a fuel tank of a motor 
vehicle of the type in which the rider rides the vehicle astride such as a 
two- or three-wheeled motor vehicle. 
2. Description of Relevant Art 
In the conventional fuel tank of a motor vehicle of the type in which the 
rider rides the vehicle astride such as a two- or three-wheeled motor 
vehicle, a separate fuel cock is suspended from the exterior of the bottom 
plate and a fuel pipe is connected to the fuel cock for communication with 
the carburettor side, and the feed or cut-off of fuel with respect to the 
carburettor side is effected by opening or closing the fuel cock. It is 
desirable for the fuel cock to have a good operability because usually it 
is closed during parking or stopping and opened just before start of 
running. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a fuel tank for motor 
vehicles of the type in which the rider rides the vehicle astride, 
comprising a bottom wall, a tank body wall which defines a fuel storing 
space together with the bottom wall, a fuel feed port formed in the tank 
body wall, a concaved portion formed in the tank body wall, a fuel cock 
embedded in the concaved portion, a fuel suction pipe extending from the 
fuel cock into the fuel storing space, and a fuel pipe extending from the 
fuel cock to the engine side of the vehicle, in which the fuel suction 
pipe and the fuel pipe can be brought into communication and out of 
communication with each other in the interior of the fuel cock. 
Accordingly, it is an object of the present invention to provide a fuel 
tank for motor vehicles including a fuel cock whose operability is very 
good when the rider rides the vehicle astride. 
It is another object of the present invention to provide a fuel tank for 
motor vehicles which permits the rider to easily confirm the operating 
knob switching position as he rides the vehicle astride. 
It is a further object of the present invention to provide a fuel tank for 
motor vehicles of a structure which permits the operating knob of a fuel 
cock to be designed as large as possible. 
It is a still further object of the present invention to provide a fuel 
tank for motor vehicles superior in workability not requiring the fuel in 
the tank to be drawn out at the time of inspection of a fuel cock. 
Other objects and advantages of the present invention will become apparent 
from the following detailed description of preferred embodiments of the 
present invention taken in connection with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring first to FIGS. 1 and 2, there is shown a fuel tank 1 applicable 
to motor vehicles such as two- and three-wheeled motor vehicles, in which 
a fuel feed port with a tank cap 2 attached thereto and a fuel cock 3 are 
disposed side by side on the upper surface of the fuel tank 1. 
The fuel cock 3 is disposed and fixed in a concave portion 16 which is 
formed by a cylindrical holder 4 and a cock base 5 integral with the 
cylindrical holder, the cylindrical holder 4 being fitted in an opening 
portion 15a integrally with a fuel tank body wall 15. 
Onto the upper surface of the cock base 5 is fixed with screws a cock 
casing 7 together with a cylindrical cover member 6 through respective 
base end side flanges 7a and 6a. The cover member 6 is provided with a 
flange 6b at the other end side thereof. The flange 6b constitutes a dial 
ring on the surface of which are indicated an ON position, an OFF position 
and a reserve (RES) position of the cock 3. In the cock casing 7 is 
rotatably fitted a valve body 8 which has a curved concaved groove 8a 
formed in the bottom thereof and which is adapted to be rotated by an 
operating knob 9 threadedly engaged therewith. 
In the cock base 5 are formed openings 5a, 5b and 5c, and also a concaved 
groove 5d which partially overlaps the opening 5c is formed in the surface 
of the cock base 5 in contact with the valve body 8, as shown in FIGS. 4 
through 6. The relation of the openings 5a, 5b, 5c and the concaved groove 
5d to the concaved groove 8a of the valve body 8 is such that when the 
operating knob 9 is in the ON position, the openings 5a and 5c are 
communicating with each other through the concaved grooves 8a and 5d (see 
FIG. 4), and when the operating knob 9 is in the OFF position turned by 
90-deg. from the ON position, the openings 5a and 5b are communicating 
with each other through the concaved groove 8a (see FIG. 6), and when the 
operating knob 9 is in the RES (reserve) position further turned by 
90-deg., the openings 5b and 5c are communicated with each other through 
the concaved grooves 8a and 5d (see FIG. 5). 
To the openings 5a, 5b and 5c are connected fuel suction pipes 20, 21 and a 
fuel pipe 22, respectively. The fuel suction pipe 21 is disposed so that a 
suction part 21a at the fore end thereof is close to a tank bottom plate 
25, while a suction part 20a at the fore end of the fuel suction pipe 20 
is disposed in a position higher by a predetermined level than the suction 
part 21a at the fore end of the fuel suction pipe 21. The fuel pipe 22 is 
connected to the suction side of an electromagnetic type fuel pump P. The 
fuel from the fuel pipe 22 is fed to a carburettor C by means of the pump 
P. 
On the other hand, the cover member 6 is formed with a drain hole 6c in a 
position adjacent to the bottom plate, and the cylindrical holder 4 is 
also formed with a drain hole 4 in a position adjacent to the cock base 5. 
To the drain hole 4a is connected a drain pipe 23, which is conducted and 
opened to the exterior of the fuel tank 1. 
The fuel pipe 22 and the drain pipe 23 are once conducted to the exterior 
of the fuel tank, more specifically, to a recessed portion 1a formed 
centrally in the front portion of the tank, in an air- and water-tight 
manner to prevent fuel leakage from the fuel tank, through a packing 10 
while being inserted into a cover pipe 24, and then conducted downward 
through an opening 1b formed in the bottom wall of the recessed portion 
1a. By the recessed portion 1a, the fuel pipe 22 and the drain pipe 23 are 
prevented from interfering with a head pipe positioned in front of the 
fuel tank. 
To an upper part of the cylindrical holder 4 there may be attached an 
L-shaped breather pipe 11 for communication between the interior and 
exterior of the fuel tank, as shown in FIG. 2. 
In the above-described construction, if the operating knob 9 of the fuel 
cock 3 is turned to the ON position as shown in FIG. 1, the openings 5a 
and 5c are communicating with each other (see FIG. 4) through the concaved 
groove 8a in the valve body 8 and the concaved groove 5d in the cock base 
5, so that while the engine is in operation, fuel is fed to the 
carburettor C side through the fuel suction pipe 20 and fuel pipe 22. 
When the fuel level has lowered to the position of the suction tip 20a of 
the fuel suction pipe 20--which can be confirmed from a change in the 
state of operation of the engine--as a result of consumption of the fuel 
in the fuel tank with vehicle running, if the operating knob 9 is turned 
by 180-deg. for switching to the RES (reserve) position, the openings 5b 
and 5c are communicated with each other through the concaved grooves 8a 
and 5d (see FIG. 5), with the result that the fuel (reserve fuel) 
corresponding to the difference in height between the suction tips 20a and 
21a of the fuel suction pipes 20 and 21 is fed to the fuel pipe 22. In 
this state, it is possible to confirm from the position of the operating 
knob 9 that the reserve fuel is being consumed. This is effective in fuel 
replenishment. 
Furthermore, if the operating knob 9 is set to the OFF position when the 
motor vehicle is to be parked, the concaved groove 8a in the valve body 8 
and the openings 5a, 5b in the cock base 5 become opposed to each other, 
so that the fuel suction pipes 20, 21 and the fuel pipe 22 are 
disconnected from each other (FIG. 6). 
In this embodiment, moreover, since the drain holes 6c and 4a are formed in 
the cover member 6 and cylindrical holder 4, respectively, rainwater or 
the like which has entered the cylindrical holder 4 is discharged to the 
exterior through the drain holes 6c, 4a and then through the drain pipe 23 
without staying in the holder 4. Besides, if the drain holes 6c and 4a are 
formed on the same left side as a side stand (not shown) which is mounted 
on the left side of the vehicle body, drainage can be promoted by a 
left-hand inclination of the vehicle body during parking. 
In the fuel tank according to this embodiment of the present invention, as 
will be apparent from the above description, the fuel suction pipes 
disposed in the fuel tank and the fuel pipe for supplying fuel from the 
fuel tank to the engine side are brought into interconnection through the 
fuel cock, and since the fuel cock is attached to the upper surface of the 
fuel tank, not only the operating knob switching position of the fuel cock 
can be easily confirmed but also the operability is so much improved; 
besides, it becomes easier to effect operation because this structure 
permits the use of the operating knob of a larger size. 
In inspecting the fuel cock, moreover, it is not necessary to take the 
trouble to draw out the fuel in the tank, and thus a good operability is 
ensured. 
A second embodiment of the present invention will be described hereinunder 
with reference to FIGS. 7 through 11. 
To a rear side portion of a fuel tank 31 in a two-wheeled motor vehicle 30 
is attached a fuel cock 33 integrally with a body wall 45 of the tank, and 
a recessed portion 47 is formed centrally at the rear end of the tank. A 
fuel pipe 52 is inserted into an opening A which is defined by a U-shaped 
notch 48a formed in a lower wall 48 of the recessed portion 47, the lower 
wall 48 being constituted by connection of the tank body wall 45 with the 
tank bottom wall 44, and a notch 49a formed in a tank fixing bracket 49 
(see FIGS. 7 through 9). 
The fuel cock 33 is disposed and fixed within a concave portion 46 which is 
formed in a rear left side of the fuel tank body. The concave portion 46 
is formed by a cylindrical holder 34 provided integrally with a cock base 
35 which holder 34 is integrally fitted in an opening portion formed in 
the fuel tank body wall 45 (see FIGS. 10 and 11). 
Onto the surface of the cock base 35 on the outward side of the tank is 
fixed with screws a cock casing 37 together with a cover member 36 which 
is provided on its base end side with a fixing flange 36a and on the other 
end side with a dial ring 36b. A cylindrical wall surface of the cover 
member 36 is opened outwardly in the form of an inverted taper, and as 
shown in FIG. 11, an extension line L of the wall surface is somewhat 
inclined downward with respect to a horizontal line H. The wall surface of 
the cylindrical holder 34 is also tapered in the same form. 
A valve body 38 having a curved concave groove 38a formed in the bottom 
thereof is fitted in the cock casing 37. The valve body 38 is capable of 
being rotated by a knob 39 integral with a disc 39a of a diameter somewhat 
smaller than the inside diameter of the dial ring 36b (see FIGS. 8 and 
11). 
A concaved groove 35d is formed in the surface of the cock base 35 in 
contact with the valve body 38. The relation between the concaved groove 
35d of the cock base 35 and the concaved groove 38a of the valve body 38, 
as well as the relation of openings 35a and 35b formed in the cock base 35 
and with fuel suction pipes 50 and 51 being connected thereto and an 
opening 35c (not shown) formed in the cock base 35 and with the fuel pipe 
52 being connected thereto, to the concaved grooves 35d and 38a are as 
previously described in connection with the first embodiment. 
The fuel pipe 52 used in this embodiment is drawn out through a packing 41 
from an opening formed in the wall of the recessed portion 47 and is 
connected to the fuel pump suction side or to the carburettor C through 
opening A formed in an intermediate position between a pair of seat rails 
42. 
The ON and RES positions of the knob 39 are in a relation turned by 
180-deg. with respect to each other as shown in FIG. 8, and both are 
opposed to each other in the vertical direction, so that the confirmation 
of position can be done easily by touching the knob 39. 
According to this embodiment, as will be apparent from the above 
description, even if rainwater or the like enters the cover member 36 or 
the gap between the cover member and the cylindrical holder 34, it will be 
discharged easily to the exterior because the inner wall surface of the 
cylindrical holder 34 and that of the cover member 36 are outwardly 
divergent. Besides, since the fuel cock 33 is attached to the left side of 
the fuel tank 31, drainage can be done more effectively by a left-hand 
inclination of the tank during parking with a side stand 60. 
Moreover, since the fuel cock 33 is attached to a rear part of the fuel 
tank 31 in a position close to a seat S, the rider can operate the fuel 
cock easily while sitting astride the seat S. Additionally, because the 
fuel cock 33 is attached to the surface of the fuel tank, the operating 
knob 39 can be enlarged structurally, and the operability is so much 
improved. 
Furthermore, since the structure associated with the fuel pipe 52 is such 
that the fuel pipe 52 is drawn out to the recessed portion 47 from the 
interior of the tank, then conducted downward through the opening A and 
connected to the carburettor C (or the suction side of the fuel pump), it 
will never interfere with the openable seat S and so will never be 
compressed by the seat. Consequently, it is possible to thin the wall of 
the pipe or reduce the pipe diameter, whereby the reduction in weight of 
the vehicle body and the reduction of cost can be attained. 
Besides, the external appearance is good because the exposed portion of the 
fuel pipe 52 is minimized. 
Referring now to FIGS. 12 through 16, there is shown a structural 
modification of the fuel cock described in the above first embodiment. In 
the following description regarding this modification, a detailed 
explanation about the constituent members of the fuel cock corresponding 
to those described in the first embodiment will be omitted. 
As shown in FIG. 13, a valve body 78 fitted in a cock casing 77 of a fuel 
cock 73 has a pair of curved concaved grooves 78a and 78b formed in the 
bottom thereof, while a cock base 75 does not have a concaved groove on 
its surface opposed to the valve body 78, it has three openings 75a, 75b 
and 75c in appropriate positions to which openings are connected fuel 
suction pipes 90, 91 and a fuel pipe 92, respectively. 
The relation in arrangement between the paired concaved grooves 78a, 78b of 
the valve body 78 and the three openings 75a, 75b, 75c of the cock base 75 
is as follows. 
When an operating knob 79 shown in FIG. 12 is turned to OFF position, the 
concaved grooves 78a and 78b of the valve body 78 are not opposed to the 
openings 75a, 75b and 75c of the cock base 75, so that the fuel suction 
pipes 90, 91 and the fuel pipe 92 are disconnected from each other (see 
FIG. 14). 
On the other hand, when the operating knob 79 is set to ON position by 
turning 45-deg. in a clockwise direction, the openings 75a and 75c are 
communicated with each other through the concaved groove 78a (see FIG. 
15), so that during operation of the engine, fuel is fed to the 
carburettor through the fuel suction pipe 90 and fuel pipe 92 by means of 
the fuel pump. 
Further, when the operating knob 79 is switched to RES (reserve) position, 
the openings 75b and 75c are brought into communication with each other 
through the concaved groove 78b (see FIG. 16), so that fuel (reserve fuel) 
in an amount corresponding to the difference in height between the fore 
end of the fuel suction pipe 90 and that of the fuel suction pipe 91 in 
the fuel tank is fed to the fuel pipe 92. 
Referring now to FIGS. 17 through 19, there is shown a further embodiment 
of the present invention, in which the motor vehicle to which the present 
invention is applied is provided with a sub-tank in addition to the 
ordinary fuel tank for increasing the tank capacity, and a fuel cock is 
attached to the surface of the sub-tank. 
In FIG. 17, a sub-tank 103 is mounted in a position from below the rear 
portion of a main fuel tank 102 to below an openable seat S.sub.1. A fuel 
cock 105 is attached to the left-hand surface of the sub-tank 103 
integrally therewith, and an operating knob 106 of the fuel cock 105 is 
fitted in an opening 104a formed in a side cover 104 which covers the 
sub-tank 103 so that the operating knob 106 is substantially flush with 
the side cover 104 (see FIG. 18). 
Furthermore, as shown in FIG. 19, a recessed portion 112 is formed 
centrally at the rear portion of the main tank 102, in which is disposed a 
main tank cock 122 as will be described later. A later-described 
connecting pipe 120 drawn out from the main tank 102 and a breather pipe 
121 are conducted downward through the main tank cock 122 and further 
through an opening B which is defined by a lower wall 113 of the recessed 
portion 112 and a tank fixing bracket 114. The connecting pipe 120 is 
connected to the sub-tank 103 so that the fuel in the main tank 102 may be 
fed into the sub-tank 103. The breather pipe 121 is connected between the 
main tank 102 and the sub-tank 103 for communication between the upper 
spaces in both tanks. 
The fuel cock 105 is disposed and fixed in a concave portion 115 formed in 
the body of the sub-tank 103. The concave portion 115 is defined by a 
cylindrical holder 107 provided integrally with a cock mounting base 108 
which cylindrical holder 107 is integrally fitted in an opening portion 
formed in a sub-tank body wall 116 (see FIG. 18). 
The structure of the fuel cock 105 per se is the same as that described in 
the foregoing first and second embodiments, and to the cock mounting base 
108 are connected fuel suction pipes 123, 124 and a fuel pipe 125 like the 
two previous embodiments. The fuel pipe 125 is drawn out to the exterior 
of the sub-tank through a packing 132 from an opening formed in a sub-tank 
bottom plate 116a and is connected to the suction side of an 
electromagnetic type fuel pump P. Further, the discharge side of the fuel 
pump P is connected with a pipe to a carburettor C. 
In the above-described construction, if the operating knob 106 of the fuel 
cock 105 is turned to ON position as shown in FIG. 17 in an opened state 
of the main tank cock 122, fuel is fed to the carburettor side through the 
fuel suction pipe 123 and fuel pipe 125 by means of the fuel pump P during 
operation of the engine. As the fuel is discharged from the sub-tank 103, 
the fuel in the main tank 102 is supplied to the sub-tank 103 through the 
connecting pipe 120. If the operating knob 106 is turned 180-deg. into RES 
(reserve) position, the fuel in the bottom portion of the sub-tank is fed 
to the fuel pipe 125 through the fuel suction pipe 124. Further, if the 
operating knob 106 is set to OFF position, the discharge of the fuel in 
the sub-tank 103 to the fuel pipe 125 is stopped. 
Moreover, during inspection and servicing of the sub-tank 103 or fuel cock 
105, if the main tank cock 122 is kept closed, it is not necessary to take 
the trouble to draw out the fuel in the main tank 102, and this is 
convenient. 
Additionally, the connecting pipe 120 and the main tank cock 122 are not 
likely to interfere with the seat S.sub.1 because they are disposed in the 
recessed portion 112 of the main tank 102. 
Since in this embodiment the fuel cock 105 is positioned below the seat 
S.sub.1, the rider can operate the cock easily while sitting astride the 
seat. Further, since the fuel tank 105 is attached to the surface of the 
subtank, it is structurally possible to enlarge the operating knob 105, 
and a good operability is thereby attained. Besides, it is not likely at 
all that the rider's foot in a riding posture will touch the operating 
knob 106, because the operating knob is substantially flush with the side 
cover 104.