JPH0525944Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to an improvement of a liquid level sensing valve for opening and closing a ventilation passage in a fuel tank of an automobile or the like.

(Prior Art) As shown in Fig. 3, the current fuel tank T for automobiles has a vapor reservoir chamber _T1 in the upper part of the tank that occupies a certain volume when the tank _is full. It is equipped with a check valve Vc to maintain the internal pressure of the tank at a predetermined level and a canister _C1 to adsorb fuel vapor when stopped and running.A first ventilation pipe _P1 is connected to the tank to prevent deformation of the tank. A second ventilation pipe P 2 equipped with another canister C ₂ for adsorbing fuel vapor during refueling is connected to the solenoid valve Sv, and the end of this second ventilation pipe _{P 2 is} It is inserted into the tank T for the required length, a liquid level sensing valve V is attached to its tip, and the solenoid valve Sv is opened by inserting the refueling nozzle n into the refueling pipe _T2 .
During refueling, much of the fuel vapor that remains in the tank is discharged to the canister _C2 side through the liquid level sensing valve V and the second ventilation pipe _P2 .

The conventional liquid level sensing valve V installed at the end of the second ventilation pipe _P2 has a tap-shaped main body 1 and a tapered seat 2b at the lower butt part, as shown in Fig. 4. A float 3 of a spherical shape or the like is housed inside the main body 1, and a plurality (usually four) of steam holes 4 are provided in the upper part of the peripheral wall of the main body 1, and a plurality of steam holes 4 are provided in the bottom wall. (4) liquid holes 5 are provided, and at the beginning of refueling, the fuel vapor in the tank is transferred to the steam holes 4 and the liquid holes 5.
When the amount of fuel increases, it enters the liquid level sensing valve V through the liquid hole ₅ , and when the liquid level reaches a certain level, the float 3 floats up as shown by the broken line and taper seat 2b. Pressed against the
The ventilation passage is closed to prevent fuel and its vapor from flowing to the ventilation pipe _P2 side.

(Problems to be Solved by the Invention) By the way, the above-mentioned conventional liquid level sensing valve has a structure in which steam holes 4 are provided in the upper part of the circumferential wall of the pot-shaped main body, and liquid holes 5 are provided in the bottom wall. When the refueling speed increases due to nozzle operation, etc., a speed difference and a pressure difference ( (the upper part is fast and low), causing the float 3 to rise.Furthermore, the float 3 may also rise due to the waving phenomenon of the fuel liquid level, and the ventilation passage will be The disadvantage is that it closes the

Therefore, this invention provides a liquid level sensing valve that is devised to prevent the float from rising easily due to the flow of steam or the undulating phenomenon of the liquid level when replenishing gasoline.

(Means for solving the problem) Based on the above-mentioned purpose, this invention consists of a tap-shaped main body, a pipe member equipped with a fitting tube and a tapered sheet, and the fitting tube is connected to the tank when refueling. A liquid level sensing valve is connected to the end of the ventilation pipe through which fuel vapor flows out, and is installed on the bottom wall of the main body having a liquid hole as a liquid level sensing valve that opens and closes the ventilation passage using a float housed in the main body. It is characterized by having a narrow mesh member stretched over it and a plurality of steam holes provided in the tapered sheet of the pipe member.

(Embodiment) Fig. 1 shows an example of a liquid level sensing valve V according to this invention, and 11 is a pot-shaped main body made of synthetic resin, light metal, etc., inside which a float 13 is housed, and a bottom A plurality of liquid holes 15 are provided in the wall, and a net member 16 of about 100 meshes is stretched over the bottom wall, and an overhanging collar 11a is provided at the upper end of the peripheral wall of the main body 11. On the collar 11a, a widening collar 12c of a pipe member 12 made of the same material as the main body 11 and consisting of a fitting cylinder 12a for the ventilation pipe _P2 , a tapered sheet 12b, and a widening collar 12c at the lower end is butted and welded. They are connected by adhesive or other means.

A plurality of steam holes 14 are formed in a portion of the tapered sheet 12b directly above the widening brim 12c.

Due to the above configuration, when refueling, the fuel level rises from the bottom of the figure in a waving manner, and fuel vapor corresponding to the rising liquid level attempts to enter the liquid level sensing valve.
The net member 16 acts as a resistance at the liquid hole 15 in the bottom wall of the main body, and fuel droplets generated during refueling adhere to the net member 16, increasing the resistance and suppressing the inflow of fuel vapor.

However, in that case, the main body 11 and the pipe member 1
By the wings 11a and 12c that spread laterally, the flow of steam is temporarily bent outward as shown by the arrow.
Enter the steam hole 14 diagonally from above and float 1
The head of the float 13 is passed through while being pressed downward to prevent the float 13 from floating up.

In addition, the net member 16 suppresses the influence of undulation caused by the rise in the liquid level, and the float 1 due to undulation is suppressed.
3 is also prevented from rising.

Thus, only when the fuel liquid level reaches a predetermined level does the float 13 rise to the surface and block the ventilation passage.

In addition, in FIG. 2, there is a protrusion 1 at the center of the bottom wall of the main body 11.
This is a modified example in which a valve 7 is provided to receive the float 13 and prevent the stick phenomenon from occurring against the bottom wall, but the function as a valve is the same as that described above.

(Effects of the invention) As described above, in this invention, a thin hole is installed on the bottom wall of the main body equipped with a liquid hole as a liquid level sensing valve that opens and closes the ventilation passage that allows fuel vapor in the tank to flow out when refilling gasoline. In addition to providing a mesh member, steam holes are also provided in the tapered sheet of the pipe section, so that the float is not affected by the undulations of the fuel liquid level that occur during refueling, and the inflow of fuel vapor from the liquid holes is suppressed. By allowing the steam to flow in through the steam holes provided in the upper tapered sheet, unnecessary floating of the float can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of this invention. FIG. 2 is a cross-sectional view of a part of the modified example. Figure 3 is a system diagram of the fuel tank and steam processing system. FIG. 4 is a sectional view of a conventional valve. In the figure, 11... main body, 11a... overhanging brim,
12... Pipe member, 12a... Fitting tube, 12b
...Tapered sheet, 12c...Spreading brim, 13
...Float, 14...Steam hole, 15...Liquid hole,
16... Net member.

Claims (1)

[Scope of utility model registration request] It consists of a tip-shaped main body, a pipe member equipped with a fitting tube and a tapered sheet, and the fitting tube is connected to the end of a ventilation pipe that allows fuel vapor in the tank to flow out during refueling, and is housed in the main body. In a liquid level sensing valve that opens and closes a ventilation passage using a floating float, a fine mesh member is stretched over the bottom wall of the main body having liquid holes, and a plurality of steam holes are formed in the tapered sheet of the pipe member. A liquid level sensing valve is provided.