JPH0379431A - Fuel tank for vehicle - Google Patents

Abstract

PURPOSE:To shift fuel among tanks without using a special pump by raising internal pressure of a tank on one side, taking advantage of the fuel returned from an engine, and shifting with pressure the fuel in the tank on one side to the tank on the other side. CONSTITUTION:Fuel is supplied to a main tank 2 through a fuel filling pipe 5 and also supplied into a sub-tank 3 through a connecting pipe 4. At this time, the air within both tanks 2 and 3 is discharged outside through a breather pipe 6. On the other hand, when an engine E is started, the fuel, which is returned from the engine E, is discharged into a pan 7. A float 8a is elevated by the fuel, which stays in the pan 7, to close an opening of the breather pipe 6. As a result, the internal pressure in the sub-tank 3 is raised, and the fuel in the sub-tank 3 is shifted by pressure into the main tank 2. Accordingly, the fuel within the sub-tank 3 can be sent with pressure into the main tank 2 without using a special pump.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a fuel tank for a vehicle in which the tank is divided into parts.

b. Conventional technology As shown in Fig. 4, conventionally the propeller shaft a
There is a fuel tank for a vehicle in which a main tank b and a sub-tank C are installed separately with a main tank b and a sub-tank C in between, and these tanks b and c are communicated with each other through a pipe d disposed above a propeller shaft a.

In such a fuel tank, one end of the fuel supply pipe e that supplies fuel to the engine faces the main tank b, and the fuel in the main tank b is supplied to the engine. In addition, in this fuel tank, when the water level of fuel in sub-tank C is higher than pipe d, fuel is supplied to main tank b by the head pressure, but when the water level becomes lower than pipe d, fuel cannot be supplied by the head pressure. Because it runs out, pump f
The fuel in the sub-tank C is pumped into the main tank b by the pump r. In FIG. 4, reference numeral g indicates a fuel recirculation pipe for returning excess fuel from the engine to the fuel tank, and the pipe 1g recirculates fuel to the main tank b.

C0 Problems to be Solved by the Invention Incidentally, in the above fuel tank, a pump f is used to transfer fuel to the sub tank C and the main tank b.

Therefore, in such a fuel tank, not only the installation space for the pump f but also the sufficient strength to hold the pump f must be maintained at 6 m, and noise countermeasures must also be taken.

Therefore, it is an object of the present invention to provide a fuel tank for a vehicle that eliminates the need for a pump and eliminates the above-mentioned problems.

d. Means for Solving the Problems In the vehicle fuel tank of the present invention, a propeller shaft, etc. is sandwiched between the tanks, and a connecting pipe is provided between the two tanks, passing above the propeller shaft, etc. At the same time, one tank faces the end of the fuel supply pipe to the engine, the other tank faces the end of the fuel return pipe from the engine, and the pleather pipe opening into the other tank faces the engine. A pulp is disposed to close the breather pipe during the fuel reflux period.

e. Function: In the vehicle fuel tank of the present invention, the internal pressure of the other tank is increased by the recirculation of fuel from the engine, and the fuel in the other tank is pumped into the one tank by this pressure.

f. Embodiment FIGS. 1 and 2 show a fuel tank for a vehicle according to the present invention.

This fuel tank is divided into a main tank 2 and a sub-tank 3, with a propeller shaft 1 in between. Both tanks 2.3 are communicated with each other through a communication pipe 4 disposed above the propeller shaft l.

One end of the communication vibe 4 extends to the bottom of the sub-tank 3. The main tank 2 is equipped with a fuel injection pipe 5.

One end of the breather vibro is connected to the vicinity of the inlet of the injection pipe 5. The vibro is branched in the middle, and each end extends to the ceilings of the main tank 2 and sub tank 3. On the other hand, a fuel receiving tray 7 is disposed on the ceiling of the sub-tank 3, and the open part of the breather vibro faces the receiving tray 7. A rollover pulp 8 is installed in the opening 6a of the breather vibro. This rollover valve 8 is equipped with a float 8a, and when the saucer 7 is filled with fuel,
The flow) 8a is pushed up by the ti fuel, thereby closing the opening 6a of the vibro. An orifice 7a is formed at the bottom of the fuel tray 7.

An outlet 9a of a recirculation pipe 9 for returning excess fuel from the engine E is faced to the fuel receiving tray 7. Note that the reference numeral 10 indicates a fuel supply pipe, and the pipe 10 has a portion 10a located at the bottom of the main tank 2.

In this vehicle fuel tank, as shown in FIG. 1, fuel is supplied to the main tank 2 through the fuel injection pipe 5.
A part of it is supplied to the sub-tank 3 via the communication vibe 4. During this time, the air in both tanks 23 is discharged to the outside via the breather vibro.

When the engine E is operated, the fuel in the main tank 2 is supplied to the engine E via the fuel supply pipe 10.

As a result, when the fuel in the main tank 2 decreases,
The fuel in the sub-tank 3 is replenished into the main tank 2 via the communication vibrator 4.

In particular, in this fuel tank, fuel recirculated from the engine E is discharged into the receiving tray 7. Then, part of it falls into the sub-tank 3 through the orifice 7a, but the rest fills the saucer 7. The fuel accumulated in the saucer 7 causes the float 8a to rise, and the opening 6a of the breather pipe 6 is closed by the float 8a, as shown in FIG. Therefore, as the recirculated fuel is subsequently discharged into the sub-tank 3, the internal pressure within the sub-tank 3 is increased. This internal pressure also causes the fuel in the sub tank 3 to be pumped into the main tank 2. In particular, as shown in FIG. 2, even if the water level of the fuel in the sub-tank 3 falls below the communication pipe 4, the fuel in the sub-tank 3 will be transferred to the main tank due to the differential pressure between the internal pressure of the sub-tank 3 and the internal pressure of the main tank 2. It is transferred into tank 2.

Here, when the engine E is stopped, the discharge of the recirculated fuel is also stopped accordingly. Then, the water level of the fuel in the saucer 7 gradually decreases, and the flow 8a also decreases accordingly, opening the opening 6a of the breather vibro again. Therefore, when refueling the fuel tank, the air in the sub-tank 3 can be released from the breather vibro to the outside.

In the above embodiment, the recirculated fuel is stored in the tray 7, and the breather vibro is closed by floating the float 8a of the rollover valve 8. However, in the present invention, for example, the engine It is also possible to adopt other means, such as detecting that E is operating and operating an electromagnetic valve or the like based on the signal, thereby closing the breather pipe.

In addition, in the above embodiment, the main tank 2 and the sub tank 3
Although a fuel tank is shown in which the main tank 2 and the sub-tank 3 are completely separated from each other, the present invention can also be applied to an integrated fuel tank in which the main tank 2 and the sub-tank 3 are defined by a partition wall 11, as shown in FIG. Of course you can.

g. Effects of the Invention As described above, the vehicle fuel tank according to the present invention pressure-feeds the fuel in the sub-tank into the main tank by the pressure in the sub-tank increased by the recirculated fuel. Therefore, there is no need for a pump, and there is no need to take measures against the problems caused by installing a pump, such as ensuring space for installing the pump, strength measures, noise measures, etc.

[Brief explanation of drawings]

1 and 2 are conceptual cross-sectional views of an embodiment of a vehicle fuel tank according to the present invention, FIG. 3 is a conceptual cross-sectional view of a modification of the tank, and FIG. 1 is a sectional view conceptually showing a conventional vehicle fuel tank. Figure 1■... Propeller shaft, 2... Main tank, 3... Sub tank, 4... Communication pipe, 5... Fuel injection pipe, 6... Breather pipe, 6a... Opening , 7... Fuel pan, 7a... Orifice, 8... Rollover valve, 8a... Float, 9
...Fuel reflux pipe, 9a... Out [1, IO・
...Fuel supply pipe, 10a...Inlet, E...
engine. Figure 2

Claims (2)

[Claims] (1) A tank is provided between each of the propeller shafts, etc., and a communication pipe is provided between the two tanks, passing above the propeller shaft, etc., and a fuel supply pipe to the engine is connected to one tank. The end of the fuel reflux pipe from the engine faces the other tank, and the breather pipe that opens to the other tank is provided with a valve that closes the breather pipe during the fuel reflux period from the engine. A fuel tank for a vehicle, characterized in that the internal pressure of the other tank is increased by recirculation of the fuel, and the fuel in the other tank is pumped to the one tank by the pressure. (2) A recirculation fuel receptacle is arranged in the other tank, and the end of the breather pipe faces the recirculation receptacle, and the water level of the recirculation fuel in the recirculation receptacle is set at the open end of the breather pipe. A fuel tank for a vehicle according to claim (1), characterized in that a valve is disposed to close the opening when raised, and an orifice is formed in the saucer for discharging the recirculated fuel in the saucer. .