JPH0134298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel pump device for a motorcycle or other small vehicle with an engine.

[Conventional technology]

Generally, this type of small vehicle is configured such that a fuel tank is provided above the engine, and fuel is supplied by gravity from the fuel tank to a mixture generator such as a carburetor or a fuel injector of the engine.

[Problem to be solved by the invention]

However, with such a structure, it is difficult to increase the fuel tank capacity. In other words, when the fuel tank is made larger, the fuel tank, which is located relatively high on the vehicle, becomes heavier.
This is because the center of gravity of the vehicle becomes higher.
Therefore, in order to solve this problem, it is possible to provide an auxiliary fuel tank and interpose a fuel pump between the auxiliary fuel tank and the mixture generator, but if the fuel pump is installed near the engine, Excessive heating can cause percolation, causing problems such as uneven fuel supply. The present invention was made in view of these circumstances, and provides a fuel pump device for a small vehicle that can increase the fuel tank capacity while suppressing the height of the vehicle center of gravity, and can smoothly supply fuel.

[Means to solve the problem]

The fuel pump device according to the present invention provides communication with the fuel tank in a space formed between the seat, the engine, and the rear wheels in a small vehicle in which a fuel tank is disposed above the engine and a seat is provided behind the fuel tank. An auxiliary fuel tank is provided, and a fuel pump is provided near the bottom of this auxiliary fuel tank, and the fuel pump and a mixture generator are provided behind the cylinder and above the crankcase. are connected by a fuel pipe.

[Effect]

In the fuel pump device of the present invention, fuel is stored in the fuel tank and the auxiliary fuel tank located near the center of the vehicle, and is supplied from the auxiliary fuel tank to the mixture generator by the fuel pump.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a motorcycle in which the present invention is implemented, in which an air-cooled engine 4 is mounted on a body frame 3 supported by front wheels 1 and rear wheels 2.
The engine 4 has a crankcase 4a and a cylinder 4b extending upward from the crankcase 4a. The crankcase 4a extends rearward, and a transmission 4c is integrally provided here. 5 is engine 4
6 is an exhaust pipe. The other end of the intake passage 5 communicates with the atmosphere via a carburetor 5a and an air cleaner 5b arranged behind the cylinder 4b. 7 is arranged above the engine and is attached to the body frame 3
The fuel tank is supported by a tank support frame extending rearward from the head pipe of the fuel tank, and a seat 31 for a passenger to ride astride is provided at the rear. The fuel tank 7 also includes an auxiliary fuel tank 7b made of synthetic resin and connected to the rear of the engine 4 through a pipe 7a. The auxiliary fuel tank 7b is disposed in a space formed between the seat 31, the engine 4, and the rear wheels 2 and located near the center of the vehicle.

Reference numeral 8 denotes a trochoid-type fuel pump installed at a position lower than the carburetor 5a and in front of the bottom of the auxiliary fuel tank 7b. It is connected to the float chamber and to the camshaft of the engine 4 via a flexible cable 11.

As shown in FIG. 2, the fuel pump 8 is fixed with bolts 13 to an opening 12 opened at the bottom front side of the auxiliary fuel tank 7b, and is housed in a case member 32 forming a rotor chamber 14 and inside the rotor chamber 14. It has an external gear 15a, an internal gear 15b, and a front cover 16a and a rear cover 16b that sandwich them in a liquid-tight manner. 1
7 is a drive shaft rotated by the flexible cable 11, and is connected to the internal gear 15b by a pin 18. 19 is an intake passage connecting the inside of the rotor chamber 14 and the vicinity of the bottom surface of the auxiliary fuel tank 7b;
A synthetic resin filter 19a having open cells is provided. 21 is a discharge pipe that also communicates with the rotor chamber 14, 22 is a hydraulic valve, and 23, 23 are seal rings.

Since this embodiment is configured as described above,
First, when the engine 4 is cranked by the starter motor, the camshaft rotates, the drive shaft 17 rotates via the flexible cable 11, and the fuel pump 8 is operated. The fuel in the auxiliary fuel tank 7b is filtered by a filter 19a and sent to the rotary chamber 14.
The fuel is sucked into the tank and discharged from the opposite side through the discharge pipe 21 into the fuel pipe 9 and supplied to the carburetor 5a. Open the auxiliary fuel tank 7
reflux into b.

Further, fuel for the motorcycle is stored in a fuel tank 7 disposed above the engine 4 and an auxiliary fuel tank 7b located below the seat 31 and near the center of the vehicle.
Since it can be stored in the auxiliary fuel tank 7
The tank capacity can be increased by b. Moreover, this auxiliary fuel tank 7b and fuel pump 8
Since these can be arranged in a concentrated manner near the center of the motorcycle, it is possible to prevent the center of gravity of the motorcycle from becoming high. Furthermore, since the fuel pump 8 is disposed at the lower part of the auxiliary fuel tank 7b and is separated from the cylinder 4a of the engine 4, the fuel pump 8 is prevented from being heated by the heat of the engine 4 and causing percolation, and the fuel supply is prevented. It can be done smoothly.

〔Effect of the invention〕

As explained above, the present invention provides a small vehicle in which a fuel tank is disposed above the engine and a seat is provided behind the fuel tank, in which a space formed between the seat, the engine, and the rear wheels is communicated with the fuel tank. An auxiliary fuel tank is provided, a fuel pump is provided near the bottom of the auxiliary fuel tank, and the fuel pump and a mixture generator are provided behind the cylinder and above the crankcase. Since they are connected by a fuel pipe, fuel can be stored in the fuel tank and an auxiliary fuel tank located near the center of the vehicle, and can be supplied from the auxiliary fuel tank to the mixture generator using a fuel pump.

Therefore, the tank capacity can be increased with the auxiliary fuel tank, and the auxiliary fuel tank and fuel pump can be arranged centrally near the center of the vehicle to prevent the center of gravity of the vehicle from becoming high. Moreover, since the fuel pump is separated from the engine cylinder, percolation due to heating does not occur, so fuel can be supplied smoothly.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a motorcycle, and FIG. 2 is an enlarged sectional view of the main parts thereof. 4...Engine, 5a...Carburizer, 7...Fuel tank, 7b...Auxiliary fuel tank, 8...Fuel pump, 9
...fuel pipe, 31...seat.

Claims (1)

[Claims] 1 In a small vehicle in which a fuel tank 7 is disposed above an engine 4 having a cylinder 4b extending upward from a crankcase 4a, and a seat 31 for a passenger to ride astride is provided behind the fuel tank 7. , the seat 31, the engine 4 and the rear wheel 2
An auxiliary fuel tank 7b communicating with the fuel tank 7 is disposed in the space formed between the auxiliary fuel tank 7b, and a fuel pump 8 is disposed near the bottom of the auxiliary fuel tank 7b. A fuel pump device for a small vehicle, which is connected by a fuel pipe 9 to an air-fuel mixture generator 5a disposed at the rear and above the crankcase 4a.