JPH0534985Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a leveling pipe structure for a fuel tank in a vehicle such as an automobile.

BACKGROUND ART In a conventional fuel tank, as shown in FIG. 4, a fuel supply pipe 2 is connected via a filler hose 3 to the lower part of a fuel tank 1 in which fuel is stored. Further, at the upper part of the fuel tank 1, a leveling pipe 4' having a substantially horizontal opening end that opens downward in the fuel tank 1 is arranged substantially horizontally.
The other end of this leveling pipe 4' was connected via a hose 5 to an upper leveling pipe 4a opening at the upper part of the oil supply pipe 2.

Note that 6 is a filler cap.

Problems to be solved by the invention By the way, in the above-mentioned conventional technology, the open end of the leveling pipe 4' in the fuel tank 1 is
As shown in Figure 5, the fuel was bent downward and the open end was held horizontally so that fuel could be supplied until the liquid surface touched the open end, but the following problems occurred. Ta.

In other words, when fuel is supplied into the fuel tank 1, if the liquid level is in the range A until it closes the opening of the filler hose 3 in FIG. Although it comes out from both sides of the pipe 4', in the range B from when the opening of the filler hose 3 is closed to when the opening end of the leveling pipe 4' is closed, it comes out only from the leveling pipe 4', so the fuel tank 1
As shown by the solid line y in FIG. 6, the internal pressure inside the tube rises slightly from the range A (section B in FIG. 6). and,
When the liquid level reaches the open end of the leveling pipe 4' and the tank becomes full C, the leveling pipe 4' is also blocked, making it impossible for air to escape. As a result, the internal pressure of the fuel tank rises rapidly, far exceeding the pressure required to stop a fuel gun (not shown) that supplies fuel, causing what is called fuel injection. Therefore, when the fuel tank is nearing full C, the person injecting the fuel should:
It was necessary to supply fuel little by little to prevent blowback.

The purpose of the present invention is to solve the above problems and prevent so-called blowback.

Means for Solving the Problems The present invention provides a fuel supply pipe that supplies fuel into a fuel tank, and a breather that discharges air in the fuel tank to the outside when supplying fuel into the fuel tank. In a fuel tank leveling pipe structure, one end extends into the fuel tank and the other end extends upstream of the fuel supply pipe. a leveling pipe connected to the leveling pipe, an open end formed at one end of the leveling pipe, and a bend formed near the open end, the upper part of which is located between the upper open end and the lower open end, and the lower part of which is the open end. The structure includes a horizontal stepped portion located below the lower portion and a small hole formed in the lower portion of the horizontal stepped portion.

Therefore, according to the above-described configuration, when fuel is supplied to the fuel tank and the liquid level reaches the lower part of the horizontal stage near the opening end of the leveling pipe, the fuel flows through the small hole provided at the lower part of the horizontal stage. Since the air gradually enters the leveling pipe and reduces the air flow path area within the horizontal step, the air is gradually discharged. Furthermore, even if the liquid level rises further and fuel enters through the opening of the leveling pipe, the upper part of the horizontal step is higher than the lower part of the opening end, so air continues to be gradually discharged.

Therefore, the air pressure within the fuel tank does not rise suddenly, and fuel can be prevented from being sprayed back during refueling.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a sectional view of a fuel tank having a leveling pipe 4 of the present invention corresponding to FIG. 4, and the same parts as in FIG. 4 are given the same reference numerals. Figure 2 shows the leveling pipe 4 in Figure 1.
FIG. 2 is an enlarged view of one embodiment. This leveling pipe 41 is provided with an open end 71 that opens in the horizontal direction, and a horizontal step portion 8 is formed near the open end. A small hole 9 is provided in the lower part of this horizontal stepped portion 8. That is, the lower part 71a of the open end 71 is bent so as to be located above the lower part of the horizontal step part 8 by a range of B ₂ and below the upper part of the horizontal step part 8 by an range of α ₁ .

With the leveling pipe structure as described above, when supplying fuel to the fuel tank, the liquid level increases from the time when the opening of the filler hose 3 is blocked until it reaches the lower part of the horizontal step 8 of the leveling hose 41.
Even if the range of B ₁ is exceeded, if fuel is further refilled, fuel will flow through the small hole 9 of the horizontal step 8 into the leveling hose 4.
1 and the air flow path in the horizontal step portion is gradually narrowed, so the air is discharged while its flow rate is restricted. Furthermore, when the liquid level rises further and exceeds the range B ₂ until it reaches the lower part 71a of the horizontally opened opening end 71, fuel will also enter from the opening end 71, narrowing the air flow path. The air flow rate is further restricted. Even so, as the liquid level rises further and reaches the range α until it reaches the upper part of the horizontal stepped portion 8 of the leveling hose 41, the air flow path is gradually closed and the discharge of air is gradually stopped.

Therefore, with the structure described above, as shown by the broken line x in _FIG .
Even when B ₂ is exceeded, the air flow path is secured although narrowed, so there is no sudden pressure change. The internal pressure eventually reaches α and the internal pressure suddenly increases, but before that the refueling gun has already stopped due to the rise in the liquid level in the filler hose, so no splashback occurs.

FIG. 3 shows another embodiment of the leveling pipe of the present invention, in which the open end 72 of the leveling pipe 42 is bent so as to open obliquely upward from the horizontal step 8. lower part 72 of
a is above the lower part of the horizontal step 8 by an area of B ₃ ,
It is bent so as to be located below the lower part of the horizontal stepped portion 8 by an amount of α ₂ . The functions and effects of this embodiment are similar to those of the embodiment shown in FIG. 2 above.

Effects of the Invention As explained above, according to the fuel tank leveling pipe structure of the present invention, even when refueling by the refueling gun approaches the full state, the leveling pipe that releases the internal pressure in the fuel tank gradually becomes clogged. Therefore, the structure is simple and convenient, as it prevents the fuel from blowing back and does not interfere with the measurement of the oil amount due to fluctuations in the liquid level due to the blowing back.

Therefore, even if the person filling the fuel gets sick and forgets to limit the amount of fuel supplied when the fuel tank is nearly full, there is no risk of fuel blowback, and safety is assured. It has the effect of further improving the

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fuel tank showing one embodiment of the present invention, FIG. 2 is an enlarged view of a leveling pipe in FIG. 1, and FIG. 3 is an enlarged view of a leveling pipe according to another embodiment. FIG. 4 is a sectional view of a conventional fuel tank, FIG. 5 is an enlarged view of the leveling pipe in FIG. 4, and FIG. 6 is a diagram showing the relationship between tank internal pressure and time. 1...Fuel tank, 2...Refueling pipe, 4,4
1, 42, 4'... Leveling pipe, 71, 7
2...Open end, 8...Horizontal step, 9...Small hole.

Claims (1)

[Scope of claim for utility model registration] A fuel supply pipe that supplies fuel into a fuel tank,
A leveling pipe that functions as a breather for discharging air in the fuel tank to the outside when fuel is supplied into the fuel tank, and as a leveling mechanism that stops discharging air when the fuel tank is full of fuel; A leveling pipe structure for a fuel tank equipped with a leveling pipe having one end extending into the fuel tank and the other end connected upstream of a fuel supply pipe, an open end formed at one end of the leveling pipe, and the open end a horizontal stepped portion that is bent in the vicinity and whose upper portion is located between the upper opening end and the lower opening end, and whose lower portion is located below the lower opening end; and a small hole formed in the lower portion of the horizontal stepped portion; A fuel tank leveling pipe structure characterized by being equipped with.