JP3067234B2 - Motorcycle fuel supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for a motorcycle.

[0003]

2. Description of the Related Art In a motorcycle, a saddle-shaped fuel tank 2 having an inverted U-shaped cross section is mounted on a tank frame 1 as an upper member of a body frame as shown in FIG. Left and right side chambers 2a, 2b of this fuel tank 2
A pipe 5 and 6 connected via cocks 3 and 4 to join a merging pipe 7 to supply fuel to a carburetor 9 of an engine 8 through the pipe 7.
Alternatively, as shown in FIG.
There is a type in which the bottoms of a and 2b are connected by an out pipe 10, a pipe 12 is connected to the bottom of one side chamber 2a via a cock 11, and fuel is supplied to the carburetor 9.

[0004]

However, according to the former configuration, since the left and right cocks 3, 4 are provided at the bottom of the side chambers 2a, 2b of the fuel tank 2, it is not only difficult to use, but also the two cocks 3, 4 , The cost increases, and two pipes must be removed when the fuel tank 2 is attached and detached, which is troublesome.

According to the latter configuration, the cock 11 is
It is necessary to take sufficient measures to prevent the fuel from leaking from the out pipe 10, and it is necessary to remove two or more pipes when attaching and detaching the fuel tank 2 as in the former case, which is troublesome. is there.

The present invention has been made in consideration of the above-described circumstances, and has been made in consideration of the above-described circumstances, and is intended for a motorcycle fuel that can easily attach and detach a fuel tank and can reliably use fuel even for a small amount of refueling. It is intended to provide a supply device. [Configuration of the invention]

[0007]

In order to solve the above-mentioned problems, a fuel supply device for a motorcycle according to the present invention has an inverted U-shaped cross-section mounted on a tank rail of a frame.
A motorcycle having a U-shaped fuel tank has an inverted U-shaped reserve pipe extending from the top in the fuel tank to near the bottom of the left and right chambers, and a main pipe is connected to the top of the pipe to form a fuel tank. The main pipe and the ON pipe inserted into the side chamber are connected to the main pipe and the ON pipe inserted into the side chamber. The fuel cock is connected and formed so as to be switchable, and a discharge port of the fuel cock is connected to a carburetor via a fuel pump.

[0008]

When the fuel tank is full, fuel is supplied through the ON pipe. If the fuel becomes low, the main bipe can be switched to use almost all of the fuel. When a small amount of fuel is replenished, it is sucked out by a fuel pump through a bypass pipe, and when a small amount of fuel is urgently supplied, the operation of the fuel pump is prevented, and the fuel is reliably supplied to the carburetor.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel supply system for a motorcycle according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a piping system of the present invention, and FIG. 2 shows a specific example of the details. FIG. 3 shows an off-road motorcycle 2 equipped with a motorcycle fuel supply device according to the present invention.
It is the whole wheel side view. The fuel tank 12 has a saddle shape having an inverted U-shaped cross section so as to be attached across the tank rail 1 of the vehicle body frame as in the prior art.
An ON pipe 13 serving as a fuel intake for normal traveling is inserted from the bottom of the fuel tank 12. In addition, an inverted U serving as a spare fuel intake from the top in the fuel tank 12 to the vicinity of the bottom of the left and right chambers 12a and 12b. A reserve pipe 14 having a V-shape is provided inside, and an upper end of a main pipe 15 is connected to a top of the pipe 14. The main pipe 15 is connected to the side chamber 1.
It is led out from the bottom of 2a.

A bypass pipe 16 is provided in the middle of the main pipe 15 in a branched manner.
An orifice 17 is provided inside 6 and inserted near the bottom of the side chamber 12a.

The ON pipe 13 and the main pipe 1
5 is connected to a fuel cock 18, which is connected to a discharge port 19 through a filter 20 and a fuel pump 21.
Is connected to the carburetor through a connected pipe 22.

The fuel cock 18 can be switched between a carburetor and an ON pipe 13, a carburetor and a main pipe 15, and OFF by operating a handle 23, and the fuel pump 18 uses an engine suction negative pressure. A negative pressure pump is used which operates.

Next, the operation will be described.

When the fuel tank 12 is full of fuel, the fuel cock 18 is switched to the ON pipe 13 for use. At this time, the fuel pump 2
1 to the carburetor. If the fuel runs out at the ON position, the fuel up to the lower position can be used efficiently and effectively by switching the fuel cock 18 to the main pipe 15 side.

Next, when the tank is refilled and becomes full, fuel is supplied through the ON pipe 13 in the same manner as described above. However, in an emergency, after the fuel is completely used through the main pipe 15, only a small amount of fuel may be supplied. In such a case, the characteristics of the fuel pump 21
Since the fuel cannot be pumped unless the inside is filled with fuel, the fuel supplied to the fuel tank 12 must reach the fuel pump 21 quickly. In such a case, the fuel does not flow out until the water level at the top of the reserve pipe 14 is filled.
The orifice 1 from this bypass pipe 16
The fuel can be filled into the fuel pump 21 through 7 and the fuel can be sent to the carburetor.

The bypass pipe 16 is connected to the main pipe 1.
If the diameter is larger than 5, the main pipe 15 of the fuel tank 12
Although the fuel flows out only from the side chamber 12a with the fuel, the fuel in the side chamber 12b on the opposite side remains, but the cross-sectional area of the bypass pipe 16 is reduced (the orifice 1 in the drawing).
7), when the initial priming water flows and the fuel pump 21 operates, the fuel is also drawn from the reserve pipe 14 side to use the fuel in the left and right side chambers 12a and 12b of the fuel tank 12. be able to.

[0018]

As described above, according to the present invention, the fuel tank can be removed by removing one pipe from the fuel cock to the carburetor, so that the fuel tank can be easily attached and detached. Even if the amount of fuel supplied to the inside is small, the fuel can be reliably supplied. Further, since only one fuel cock is required, there is no trouble in operation and the cost is advantageous.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a piping structure of an embodiment of a fuel supply device for a motorcycle according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a side view showing a motorcycle to which the present invention is applied.

FIG. 4 is an explanatory view showing a conventional fuel supply device for a motorcycle.

FIG. 5 is an explanatory view showing another example of a conventional motorcycle fuel supply device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank rail 2 Fuel tank 8 Engine 9 Carburetor 12 Fuel tank 12a, 12b Side chamber 13 ON pipe 14 Reserve pipe 15 Main pipe 16 Bypass pipe 17 Orifice 18 Fuel cock 121 Fuel pump

Claims (1)

(57) [Claims] 1. A motorcycle provided with a fuel tank having an inverted U-shaped cross-section mounted over a tank rail of a frame, wherein an inverted U-shaped reserve pipe extending from the top in the fuel tank to near the bottom of the left and right chambers is provided. A main pipe is connected to the top of the pipe and led out of the fuel tank.A bypass pipe is branched from the main pipe, and the bypass pipe is inserted near the bottom of the fuel tank. ON inserted into the main pipe and the side chamber
A fuel supply device for a motorcycle, characterized in that a pipe is connected to a fuel cock so as to be switchable, and a discharge port of the fuel cock is connected to a carburetor via a fuel pump.