JPH01297322A - Fuel outflow preventing device - Google Patents

Abstract

PURPOSE:To lessen diametrally an inlet pipe by the wall thickness of its main body by constituting a nonreturn valve interposed in the inlet pipe with its spherical valve which may be removed by the vibration of a vehicle and the like, and of its tubular main body which has a columnar holding portion for the holding the valve. CONSTITUTION:An inlet pipe 11 has its one edge inserted into a fuel tank 12 and fixed thereto, and also has its other edge protruding outside of the fuel tank 12, and a filler hose 14 is connected to this protrusive portion at the one edge thereof. A filler cap 17 is secured to the other edge of the filler hose 14 via a filler neck 16. And a nonreturn valve 1 is arranged inside the inlet pipe 11. In this case, the nonreturn valve 1 is formed by four pieces of columnar holding portions 18 at the center portion of the tubular main body 4 thereof. Respective holes 19 where fuel passes through are formed and interposed among the columnar holding portions 18, and also respective spherical valves 5 which may be removed by the vibration of vehicle and the like are held in each of the columnar holding portions 18.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel outflow prevention device with an improved check valve.

(Conventional technique) In vehicles such as automobiles, a check valve is installed in the inlet vibe from the filler hose to the fuel tank, and the vibrations that occur during driving cause the fuel oil in the fuel tank (hereinafter referred to as fuel) to leak outside. This is to prevent it from leaking. In other words, if the pressure in the fuel tank rises above a predetermined value due to a sharp turn while the vehicle is running or a sudden stop due to a collision, the fuel will flow through the inlet pipe due to this pressure. rise If the dynamic pressure acting on the fuel at this time is greater than the sealing pressure of the filler cap, the fuel will flow out from the filler cap. Therefore, a check valve is installed in the inlet vibe to prevent this kind of situation from occurring.

A conventional check valve will be explained with reference to FIG. This check valve l includes a cylindrical main body 4 having an opening 2 at the upper end and an opening 3 at the lower end, and a movable valve mounted inside the main body 4 so as to be movable in the longitudinal direction of the main body 4. The structure has a body 5. In this case, the movable valve body 5 uses a metal ball. Inside the main body 4, a drum-shaped passage 6 in which a double chain is communicated with the opening 2 is formed. , so as not to go in the E direction beyond the minimum diameter portion 7 of this passage 6. The lower part of the passage 6 is formed into a passage 8 having a circumferential diameter communicating with the opening 3, and the opening 3 is provided with a protrusion 7 for preventing the valve body 5 from falling.

The conventional 1Lzh valve l with such a configuration has the 11th [′f
Make it small to A) and connect the main body 4 to the inlet pipe 1! It is installed by being press-fitted inside. Assuming that the pressure rises enough to push up the movable valve body 5 while the vehicle is moving with the reverse IL valve 1 removed in this way, the movable valve body 5 moves inside the main body 4 L: 51shi, a small diameter. It will be seated on section 7 from the inside. This will prevent fuel from flowing out. Here, a consideration will be given to problems caused when the non-return tab f1 is provided. By providing the check valve l inside the inlet vibe 11, the fuel flow path area is reduced compared to when it is not provided. This increases the resistance to fuel inflow, which may result in jetting back when the fuel '1 is injected, resulting in an injection failure. Therefore, when providing the check valve l, it is necessary to increase the size of the inlet vibe 11 and increase the flow path area compared to the case where the check valve l is not provided.
This resulted in revisions and cost increases. Therefore, increasing the size of the inlet vibe 11 must be avoided as much as possible.

(Problem to be Solved by the Invention) This problem will now be discussed with respect to the conventional check valve l described with reference to FIGS. 10 and 11. This reverse 11-
For valve l, the minimum flow area S in the inlet system
(Cross-hatched portion in Fig. 12) is the area of the section ■-■ in Fig. 11, and the inlet vibe 11
From the inner diameter cross section Ms+ (hatched section in Figure 1) to the cross-sectional area S2 of the thick portion of the check valve 1 (hatched section with broken lines in Figure 14) and the cross section is of the movable valve body 5: + (
The hatched portion in FIG. 15 is subtracted, and is expressed by the following equation.

S=S+ -(St +S3) (1) In the conventional check valve 1 expressed in this way, as will be described later, there is waste due to the thickness of the inlet vibe 11, and the inlet vibe This created a limit to the reduction in diameter of 11.

The present invention was made to solve this problem.

(Means for Solving the Problems) As a means for solving the problems described above, the present invention provides a vehicle in which a check valve l is interposed in an inlet vibe 11 extending from a filler hose 14 to a fuel tank 12. The valve 1 is configured to have a main body 4 having a movable valve body 5 that moves due to vibrations of the vehicle, etc., and a columnar holding portion 18 that movably holds the movable valve body 5. .

(Function) With such a configuration, fuel is transferred to the columnar holding part 1 during injection.
8, the diameter of the inlet vibe 11 can be made smaller by the thickness of the main body 4 of the check valve l.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5, in which the same members as in FIGS. 10 and 11 are given the same reference numerals. In FIG. 1, reference numeral 12 denotes a fuel tank, into which the inlet vibe 11 is inserted and fixed. A portion of the inlet vibe 11 protrudes outside the fuel tank 12, and the lower end of a filler hose 14 is connected to this portion by a filler hose clamp 13. The upper end of the filler hose 14 is connected to the lower end of the filler neck 16 by a filler hose clamp 15.
A filler cap 17 can be detachably attached to the north end of the filler neck 1G.

Inside the inlet vibe 11, there is a reverse 11-
Valve l is installed. This check valve 1 will be explained in an enlarged manner with reference to FIGS. 2 to 4. The basic structure of this check valve l is that a ball is loaded inside the cylindrical main body 4.
There is no difference from the conventional one mentioned above. In this non-return brake rl, the main body 4 from the upper part to the lower part is not entirely cylindrical, but the middle part to the lower part is formed by four columnar holding parts 18. As a result, holes 19 are formed between the columnar holding parts 18, so that the fuel injected from the opening 2 passes through the holes 19 into the inlet pipe ll.

Here, the flow path area of the check valve 1 according to the present invention will be considered. The minimum flow path surface MS' (the cross-hatched portion in FIG. 6) is the area of the section ■-■ in FIG. Column-shaped holding part 18 of stop valve l
cross-sectional area S2 (four locations in FIG. 8) and cross-sectional area S3 of the movable valve body 5 (hatch and ring portions in FIG. 9)
There is a subtraction value, which can be expressed as the following formula.

S'= S'l - (S'2 + S', )...
(2) Here, the above-mentioned prior art and the present invention will be compared. Assuming that the minimum flow path area is the same value (S = S'), the following equation holds true from equations (j) and (2) (then the cross-sectional area of the movable valve body 5 is 5x = 31 ).

S, - (S, +S Yu) = 31 (S2 ``5)) S: + = S: + from s, -52 = s, -s2 here S
2 >>S'2(S'2: The cross-sectional area is small because the columnar holding part 18 is thin), so if S2 is ignored, S, -52=S, (3) , this formula means that the inner diameter cross-sectional area of the conventional check valve and the inner diameter cross-sectional area of the inlet pipe 11 according to the present invention are equal. That is, according to the invention, the inlet pipe 1 is thicker than the conventional one by the thickness of the main body 4.
In addition to reducing the diameter of 1, reducing the size of the filler hose 14 and filler hose clamp related to the ret vibrator 11 also becomes a problem.

In the embodiments described above, a ball is used for the movable valve body 5, and the columnar holding portion 18 is formed into a shape that is contracted in the opposite direction, but the present invention is not limited to this. The movable valve body may have a triangular cross-sectional shape, and the columnar holding portion 18 may have a horizontal shape.

(Effects of the Invention) Since the present invention is a fuel outflow prevention device configured as described above, it is possible to reduce the size of parts related to the inlet pipe when the flow path resistance at the time of fuel inflow is set to a constant value. In this way, it will be possible to reduce IHT and reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the usage state of an embodiment of the present invention, Fig. 2 is an enlarged iE hemogram of the reverse 112 valve in Fig. 1, and Fig. 3 is the decathogram of Fig. 2; Fig. 4 is a perspective view of the one shown in Fig. 2, Fig. 6 is a sectional view taken along line V-V in Fig. Figures 7 to 9
The figure is an explanatory diagram of the flow path area, and Figure 1O is the conventional inverse +t: j
FIG. 11 is a sectional view taken along the line XI-XI in FIG. 10, FIG. 12 is a sectional view taken along the penalty line in FIG. FIG. 3 is an explanatory diagram of flow path area. 1...Reverse 1-way valve 4...Body 5...Movement 11Body 11...Inlet pipe 12...Fuel tank 14...Filler hose 18...Column-shaped holding part patent Applicant Suzuki Automatic Tun Co., Ltd., 0
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Claims (1)

[Claims] (1) In a vehicle in which a check valve is installed in the inlet pipe leading from the filler hose to the fuel tank, the check valve is equipped with a movable valve body that moves due to vibrations of the vehicle, etc., and the movable valve body is movable. 1. A fuel spill prevention device comprising: a main body having a columnar holding portion for holding the fuel;