JPH04303091A - Fuel supply system for motorcycle - Google Patents

Abstract

PURPOSE:To facilitate a job for setting a fuel tank and vice versa by connecting a main pipe to the top of an inverted U-shaped reserve pipe leading to the neighborhood of each bottom of both symmetrical side chambers from a top part in the fuel tank, deriving it to the outside of this tank, and simultaneously installing a bypass pipe in the main pipe as branched off. CONSTITUTION:An inverted U-shaped reserve pipe 14, leading to the neighborhood of each bottom part of both symmetrical side chambers 12a, 12b from a top part in a fuel tank 12 is installed thereinto, and a main pipe 15 is connected to a top part of the reserve pipe 14, thereby deriving it to the outside of the fuel tank. Then, a bypass pipe 16 branched off from the main pipe 15 is inserted into a spot nearer to the tank 12, and the main pipe 15 and an ON- pipe 13 being attached to the side chamber 12a are connected to a fuel cock 18, making them free of switching motion, and a discharge port 19 of the fuel cock 18 is connected to a carburetor via a fuel pump 21. With this constitution, the fuel tank is removable by only taking off one pipe and, what is more, fuel is surely feedable even if an amount of oil supply is little in quantity.

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 system for two-wheeled motor vehicles.

0003

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

0004

However, according to the former configuration, the left and right cocks 3, 4 are located at the bottom of the side chambers 2a, 2b of the fuel tank 2, which is not only difficult to use, but also makes it difficult to use the two cocks 3, 4. It is costly because it requires
Moreover, when attaching and detaching the fuel tank 2, two pipes must be removed, which is time-consuming.

According to the latter configuration, the cock 11 is
However, there is a problem that sufficient measures must be taken to prevent fuel leakage from the out pipe 10, and as in the former case, two or more pipes must be removed when attaching or detaching the fuel tank 2, which is troublesome. be.

The present invention has been made in consideration of the above-mentioned circumstances, and provides a fuel for motorcycles that allows for easy attachment and detachment of the fuel tank and allows reliable use of fuel even when refueling in small quantities. The purpose is to provide a feeding device. [Structure of the invention]

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the fuel supply device for a two-wheeled motor vehicle according to the present invention is provided with an inverted U-shaped cross section that is attached to straddle the tank rail of the frame.
In a motorcycle equipped with a fuel tank shaped like the shape of a fuel tank, an inverted U-shaped reserve pipe is installed inside the fuel tank that runs from the top of the fuel tank to near the bottom of the left and right side chambers, and a main pipe is connected to the top of this pipe to connect the fuel tank. At the same time, a bypass pipe is branched off from this main pipe, and this bypass pipe is inserted near the bottom of the fuel tank, and the main pipe and the ON pipe inserted into the side chamber are connected to the fuel cock. The discharge port of this fuel cock is connected to a carburetor via a fuel pump.

[0008]

[Operation] When the fuel tank is full, fuel is supplied through the ON pipe. When the fuel is low, you can switch to the main pipe and use almost all the fuel. When a small amount of fuel is refilled, it is sucked out by the fuel pump through the bypass pipe, preventing the fuel pump from operating in the event of an emergency refueling, and ensuring that the fuel is supplied to the carburetor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a fuel supply system for a two-wheeled motor vehicle according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a piping system according to the present invention, and FIG. 2 shows a detailed example thereof. Figure 3 shows an off-road motor vehicle 2 equipped with a fuel supply system for a two-wheeled motor vehicle according to the present invention.
FIG. 3 is an overall side view of the wheeled vehicle. The fuel tank 12 has a saddle shape with an inverted U-shape in cross section so that it can be mounted astride the tank rail 1 of the vehicle body frame as in the past, and one side chamber 12
An ON pipe 13 is inserted from the bottom of the fuel tank 12 to serve as a fuel intake port for normal driving, and an ON pipe 13 is inserted from the bottom of the fuel tank 12 to near the bottom of the left and right side chambers 12a, 12b to serve as a backup fuel intake port. A U-shaped reserve pipe 14 is installed inside, and the upper end of a main pipe 15 is connected to the top of this pipe 14, and this main pipe 15 is led out from the bottom of the side chamber 12a.

A bypass pipe 16 is branched off in the middle of this main pipe 15, and this bypass pipe 1
6 has an orifice 17 inserted near the bottom of the side chamber 12a.

[0012] The ON pipe 13 and the main pipe 1
5 is connected to a fuel cock 18, and this fuel cock 18 has a filter 20 and a fuel pump 21 connected to the outlet 19 of the fuel cock 18.
is connected to the carburetor through a pipe 22 connected to the carburetor.

The fuel cock 18 can be switched in three ways by operating a handle 23: carburetor and ON pipe 13, carburetor and main pipe 15, and OFF.Furthermore, the fuel pump 18 utilizes the engine's suction negative pressure. A negative pressure pump is used.

Next, the operation will be explained.

When the fuel tank 12 is full of fuel, the fuel cock 18 is switched to the ON pipe 13 side for use. At this time, the fuel pump 21 is connected through the ON pipe 13.
is sent to the carburetor. When the fuel runs out in the ON position, by switching the fuel cock 18 to the main pipe 15 side, the fuel up to the lower position can be used efficiently and effectively.

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

Furthermore, 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
The fuel in only one side chamber 12a will flow out, and the fuel in the opposite side chamber 12b will remain, but the cross-sectional area of this bypass pipe 16 is reduced (in the figure, the orifice 1
7), when the initial priming water flows and the fuel pump 21 operates, the fuel in the left and right side chambers 12a, 12b of the fuel tank 12 is used by sucking out fuel from the reserve pipe 14 side as well. 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, making it easy to attach and detach the fuel tank. Even if the amount of fuel supplied into the interior is small, fuel can be reliably supplied. Furthermore, since only one fuel cock is required, there is no trouble in operation and it is advantageous in terms of cost.

[Brief explanation of 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 the main part of FIG. 1.

FIG. 3 is a side view showing a two-wheeled motor vehicle to which the present invention is applied.

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

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

[Explanation of symbols]

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

Claims (1)

[Claims] Claim 1: In a two-wheeled motor vehicle equipped with a fuel tank having an inverted U-shaped cross section that is attached to straddle the tank rail of the frame, an inverted U-shaped reserve pipe extending from the top of the fuel tank to near the bottom of the left and right side chambers is provided. A main pipe is connected to the top of this pipe to lead out of the fuel tank, and a bypass pipe is branched from this main pipe, and this bypass pipe is inserted near the bottom of the fuel tank. O inserted into the main pipe and the side chamber
The N pipe is connected to the fuel cock and can be switched freely.
A fuel supply device for a two-wheeled motor vehicle, characterized in that a discharge port of the fuel cock is connected to a carburetor via a fuel pump.