JPH08132896A - Fuel supply device - Google Patents

Abstract

PURPOSE: To absorb inertial reaction energy after the stop of oiling to a fuel tank so as to prevent the spitting of fuel. CONSTITUTION: A fuel supply device has a filler pipe 11 with one end having a fuel filling port 11a formed and with the other end 11b communicated with a fuel tank 10, a one-way valve 14 provided at the filler pipe 11 so as to impede the flow of fuel from the other end 11b side to one end 11a side, and a curved part 11d formed at the other end 11b of the filler pipe 11 so as to be positioned on the fuel tank 10 side and also positioned in the fuel tank 10.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fuel supply system.

[0002]

2. Description of the Related Art A fuel supply device for refueling a fuel tank of a vehicle needs to smoothly inject fuel. As a conventional fuel supply device, as shown in FIG. 3, a filler pipe 2 for injecting fuel into a fuel tank 1 has a one-way valve that allows a fuel flow only in a direction from an inlet 2a side to an outlet 2b side of the fuel tank 1. There is a structure in which 3 is provided to suppress the occurrence of a change in tank internal pressure.
Further, in Japanese Utility Model Laid-Open No. 4-80716, as shown in FIG. 5, the vicinity 4b of the filler pipe 4 on the outlet 4a side in the fuel tank 5 is formed into a substantially V-shaped convex downward to form a liquid reservoir and the outlet 4a. There is disclosed a structure in which a one-way valve 6 which permits the flow of fuel only from the side of the filler pipe 4 to the side of the fuel tank 5 is provided.

[0003]

However, in the fuel supply device having the structure shown in FIG. 3, the filler pipe 2 is used.
Since the side of the fuel tank 1 is substantially horizontal, the liquid cannot be completely accumulated in the pipe 2c on the downstream side of the one-way valve 3, and the tank internal pressure changes during refueling as shown in FIG. Fuel evaporation and refueling inertia energy are factors that increase the tank internal pressure.

In FIG. 4, the tank internal pressure gradually rises due to fuel evaporation as shown by the shaded area I between the time when the fuel supply is started and the time immediately before the fuel supply is stopped (gun stop). Even after the time point T1 when the fuel supply is stopped, it continues to rise as it is due to the refueling inertial energy Ei, drops sharply after reaching the peak value, further falls due to the inertial reaction energy Er, and rises again to reach the static value. Settle down to a pressure that balances with. After that, the tank internal pressure gradually rises as shown by the hatched portion II due to the fuel evaporation.

The one-way valve 3 is provided to reduce the refueling inertia energy. However, the fuel flowing back through the one-way valve 3 contains a large amount of gas such as suction air at the time of refueling. The effect) may be weakened, and this becomes reaction energy Er, and the blowback prevention effect is halved. That is, the inertial reaction energy E
Since the mixture of the intake air and the fuel flows backward due to r, the blocking effect of the one-way valve 3 is low, and the fuel accumulated on the downstream side of the one-way valve 3 is blown back from the injection port 2a. If a one-way valve 3 of zero seal having excellent sealing property is used to prevent the blowback, there is a problem that the cost becomes very high.

Further, in the fuel supply device having the structure shown in FIG. 5, the one-way valve 5 has the outlet 4a of the filler pipe 4.
Since it is installed in the fuel cell, the damming effect is low, the inertial reaction energy can hardly be prevented, and the blowback of fuel cannot be effectively prevented as in the fuel supply device shown in FIG. is there. The present invention has been made in view of the above points, and it is possible to effectively prevent blowback of fuel even if a low-cost one-way valve is used, and to provide a fuel supply device having good refueling property. To aim.

[0007]

To achieve the above object, according to the present invention, a filler pipe having a fuel inlet formed at one end and communicating with a fuel tank at the other end; A one-way valve that blocks the flow of fuel from one end to the other end, and a curved portion that is formed at the other end of the filler pipe and that is located on the fuel tank side and that is located inside the fuel tank Is.

According to a second aspect of the present invention, the curved portion has a U-shape that is convex downward. According to the third aspect, the outlet opening of the filler pipe and the horizontal portion on the upstream side of the curved portion are arranged at substantially the same height. According to the fourth aspect, the outlet opening of the filler pipe is arranged at a position lower than the opening position of the leveling pipe in the fuel tank.

[0009]

[Function] The curved portion formed immediately downstream of the one-way valve (fuel tank side) is a liquid pool (fuel pool), and all the substances flowing back to the inlet side after refueling stop becomes fuel (liquid), causing inertia. The reaction energy is this fuel (liquid)
And is absorbed by the resistance of the one-way valve. This effectively prevents blowback.

According to the second aspect of the present invention, the curved portion has a U-shape that is convex downward, so that the fuel (liquid) is sufficiently stored. Then, the substance blocked by the one-way valve is only fuel (liquid), and the one-way valve effectively operates. According to the third aspect, the outlet opening of the filler pipe and the horizontal portion on the upstream side of the curved portion have substantially the same height, and the injected fuel satisfactorily flows into the fuel tank. Therefore,
The refueling property is not impaired.

According to the present invention, since the outlet opening of the filler pipe is arranged at a position lower than the opening position of the leveling pipe in the fuel tank, the leveling pipe acts without impairing its function, Detect the level when the tank is full.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In FIG. 1, a side surface 10 a of the fuel tank 10
A substantially central portion 11c of the filler pipe 11 is penetrated through a hole 10b formed substantially at the center of and is liquid-tightly fixed. In the filler pipe 11, the injection port 11a side sharply rises obliquely upward from the central portion 11c, and
a is located substantially above the fuel tank 10. A filler cap 12 is attached to the inlet 11a. The central portion 11c of the filler pipe 11 is substantially horizontal (hereinafter referred to as "horizontal portion 11c"), and its substantially central position is fixed to the side surface 10a of the fuel tank 10.

The filler pipe 11 has a curved portion 11d formed by bending the downstream side of the horizontal portion 11c so as to face downward, and further by being curved so as to face upward so as to be convex downward in a substantially U shape. 11b is opened so as to face upward at substantially the same height as the horizontal portion 11c. And this bending part 1
1d is a fuel pool (liquid pool) of the fuel injected into the filler pipe 11.

The upper end 13a of the leveling pipe 13 is communicatively connected to the filler pipe 11 in the vicinity of the inlet 11a,
The lower end 13b is introduced into the fuel tank 10 through a small hole 10c formed in an upper portion of the side surface 10a of the fuel tank 10, and the lower end 13b is located at a predetermined height position of the fuel tank 10, that is, when the fuel is full. The tongue position h is opened downward. The leveling pipe 13 is liquid-tightly penetrated and fixed to the hole 10c of the side surface 10a. The outlet 11b of the filler pipe 11 is arranged at a position lower than the open end 13b of the leveling pipe 13.

A one-way valve 14 is provided at, for example, a substantially central position of the horizontal portion 11c of the filler pipe 11, and the one-way valve 14 allows the fuel flow only in the direction from the inlet 11a side to the outlet 11b side. It is arranged to. The one-way valve 14 is not strictly required to have a sealing property, and the currently used one-way valve as shown in FIG. 3 is sufficient.

The fuel tank 10 includes the tank 10 concerned.
An evaporative tube that guides the vaporized gas inside the canister, a return tube that returns fuel from the fuel injection valve of the engine to the fuel tank 10, a baffle plate that prevents the vibration of the fuel in the fuel tank 10, the amount of fuel in the fuel tank 10 is detected A unit gauge and the like are provided, but they are all omitted.

The operation will be described below. Filler pipe 1
The fuel injected by the filler gun (not shown) from the first injection port 11a passes through the one-way valve 14, the curved portion 11d, and the outlet 11b into the fuel tank 10. As fuel is injected into the fuel tank 10, the tank internal pressure due to fuel evaporation gradually rises as shown by the hatched portion I in FIG. 3, and the tank internal pressure sharply increases immediately before the tank is full. Then, the tank internal pressure continues to increase due to the refueling inertial energy Ei even after the time T1 when the fuel supply is stopped, reaches the peak value, and then decreases.

The leveling pipe 13 serves as an air vent for smoothly injecting fuel into the fuel tank 10, and at the time of fuel injection, the liquid level rises to the full tank position h and the open end 13b is closed. In this case, the air in the tank is not easily released, and the fuel is prevented from flowing into the tank beyond the full tank position. As a result, excessive fuel supply to the fuel tank 10 is prevented.

By the way, in the filler pipe 11, a curved portion 11d provided immediately downstream of the one-way valve 14 of the horizontal portion 11c (on the side of the fuel tank 10) forms a liquid pool, and the liquid pool is filled with fuel. ing. Therefore, after the fuel supply is stopped due to this liquid pool, the inside of the filler pipe 11 is changed from the fuel tank 10 side to the one-way valve 14
All the substances that flow back toward the tank become fuel (liquid).
As a result, the inertial reaction energy Er is absorbed by the resistance between the fuel (liquid) and the one-way valve 14, and as shown in FIG. Settle in.
As a result, blowback of fuel is prevented. After that, the tank internal pressure gradually rises as shown by the shaded portion II due to the fuel evaporation.

The substance that flows back in the filler pipe 11 from the fuel tank 10 side toward the one-way valve 14 is only liquid (fuel), so that the blocking effect by the one-way valve 14, that is, the energy reduction effect is very high. . Therefore, the one-way valve 14 does not need to be a zero-seal with high sealing property, and as described above, if it has the sealing property of the current one-way valve shown in FIG. 3, it can sufficiently cope with blowback. . Also,
Since the position of the outlet 11b of the curved portion 11d of the filler pipe 11 is at substantially the same height as that of the horizontal portion 11c, there is no problem with refuelability, and the fuel injected from the inlet 11a is stored in the fuel tank 10. Flow well into.

[0021]

As described above, according to the present invention, the curved portion formed immediately downstream of the one-way valve (fuel tank side) serves as a liquid pool (fuel pool).
After refueling is stopped, all the substances that flow back to the inlet side are only fuel (liquid), and the inertial reaction energy is this fuel (liquid).
Is absorbed by the resistance of the one-way valve, and as a result, blowback of fuel is effectively prevented. Further, by disposing the curved portion in the fuel tank, the space between the filler pipe and the fuel tank can be effectively used.

In the second aspect, since the curved portion has a U-shape which is convex downward, the fuel (liquid) is sufficiently stored, and the substance blocked by the one-way valve is only the fuel (liquid). As a result, the one-way valve works effectively. In addition, as the one-way valve, a current one that is not particularly a zero seal with excellent sealing property can be used, a low-cost one-way valve can be used, and the cost of the fuel supply device can be reduced.

According to the present invention, since the outlet opening of the filler pipe and the horizontal portion on the upstream side of the curved portion have substantially the same height, the injected fuel can satisfactorily flow into the fuel tank, and refuelability is improved. Is not damaged. In claim 4,
Since the outlet opening of the filler pipe is arranged at a position lower than the opening position of the leveling pipe in the fuel tank, the function of the leveling pipe is not impaired.

[Brief description of drawings]

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

FIG. 2 is a graph showing a change in tank internal pressure during refueling of the fuel supply system of FIG.

FIG. 3 is a cross-sectional view of a conventional fuel supply device.

FIG. 4 is a graph showing a change in tank internal pressure during refueling of the fuel supply system of FIG.

FIG. 5 is a cross-sectional view of essential parts showing another example of a conventional fuel supply device.

[Explanation of symbols]

 10 Fuel Tank 11 Filler Pipe 11a Inlet 11b Outlet 11c Horizontal Part 11d Curved Part (Liquid Pool) 12 Filler Cap 13 Leveling Pipe 14 One-way Valve

Claims (4)

[Claims] 1. A filler pipe having a fuel injection port formed at one end and the other end communicating with a fuel tank, and a one-way valve provided in the filler pipe to prevent the flow of fuel from the other end side to the one end side. A fuel supply device, comprising: a curved portion formed at the other end of the filler pipe, the curved portion being located on the fuel tank side and being located inside the fuel tank. 2. The fuel supply device according to claim 1, wherein the curved portion has a U-shape that is convex downward. 3. The fuel supply device according to claim 1, wherein the outlet opening of the filler pipe and the horizontal portion upstream of the curved portion are arranged at substantially the same height. 4. The fuel supply device according to claim 1, wherein the outlet opening is arranged at a position lower than an opening position in the fuel tank of the leveling pipe.