JPH0530507Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a valve device for processing fuel vapor generated when refueling a fuel tank of a vehicle.

(Prior Art) Current vehicles are equipped with a fuel vapor processing device as schematically shown in FIG. and a first charge mechanism, which is connected by a first ventilation passage _l1 in which a shutoff valve 3b is arranged, and which sends fuel vapor generated in the fuel tank 1 when the vehicle is stopped or running into the main canister 2;
A gate valve 4 is provided on the inlet pipe 1a of the tank, which is opened and closed by inserting and removing the refueling nozzle n, and this gate valve 4 is connected to the upper space inside the tank 1 through a second ventilation passage _l2 , and is also connected to the sub-canister 5. A second charge mechanism sends fuel vapor generated in the tank to the sub-canister 5 when refueling the main canister 1, and the main and sub-canisters 2 and 5 are connected to the intake pipe of the engine by a purge passage l ₃ and a negative pressure introduction passage l ₄ . , canister 2, due to intake negative pressure associated with engine load.
5 and a purge mechanism that removes the adsorbed fuel from the fuel and sends it into the intake pipe.

The base end of the second ventilation passage _l2 protrudes into the upper space of the tank 1, and a liquid level sensing valve v housing a float 7 in a valve body 6 is provided there, and the liquid level due to refueling is provided there. The float 7 rises as the tank rises, and when the tank is nearly full, the float 7 contacts the tapered sheet surface 6a to close the entrance of the second ventilation passage _l2 , and the liquid level in the inlet pipe 1a rises accordingly. The refueling nozzle n senses this and stops refueling.

(Problem to be solved by the invention) By the way, in the liquid level sensing valve described above, as the float 7 rises as refueling increases, the opening area formed between the float 7 and the tapered seat surface 6c gradually becomes smaller. , even though the outflow of fuel vapor decreases, the refueling speed by nozzle n (30 to 60/min at market level) remains the same, so the liquid level in the inlet pipe 1a rises, and the refueling nozzle n The second ventilation passage may detect the liquid level and become unable to refuel, and unlike the first ventilation passage, _{the second} ventilation passage does not have a means to cut off fuel in the event of a vehicle falling over. Furthermore, if the vehicle overturns and the passageway _L2 is damaged, there is a risk that the fuel in the tank may leak out.

Therefore, the present invention provides a valve device that can increase the amount of fuel supplied to the fuel tank and can immediately shut off the entrance to the second ventilation passage when the vehicle falls over.

(Means and effects for solving the problem) Based on the above-mentioned purpose, this invention provides a second ventilation passage in the tank that connects the upper space of the fuel tank to the canister via the gate valve on the inlet pipe. A main valve, which is attached to the base end of the second ventilation passage and consists of a pot-like body and a pipe portion that also serves as a lid body, is attached to the base end of the second ventilation passage as a valve device for circulating and shutting off fuel vapor during refueling. A tapered seat surface and a steam vent are sequentially provided in the pipe section, and a bypass pipe that communicates with the inside is installed at the top of the tapered seat surface, and the tip of the bypass pipe is connected to the main valve body. It is characterized in that the valve body of the sub-valve is vertically positioned above, and a float and a weight ball are accommodated in the main valve body and the sub-valve body, respectively.

When refueling the fuel tank, most of the fuel vapor generated in the tank passes through the steam vent of the main valve, and a portion passes through the vent of the sub-valve and the bypass pipe to the second ventilation. As the liquid level rises, the main float is actuated and contacts the tapered sheet surface to close the passage. The liquid level rises and the nozzle tip senses this and stops the primary oil supply.
At that time, the bypass pipe is in a state where steam can flow out, and the fuel in the tank settles down, and the liquid level in the inlet pipe falls, making it possible to refuel. When refueling, the secondary float of the secondary valve operates to close the bypass line.

Additionally, when the vehicle overturns or leans significantly, the weight balls inside the main and sub valve bodies immediately push up each float, locking the steam passage.

(Embodiment) FIGS. 1 and 2 show an embodiment of this invention, which shows a first ventilation passage in which a two-way valve 3a and a cutoff valve 3b are disposed in the upper space of a fuel tank 1. Connect to main canister 2 with l ₁ ,
Fuel vapor generated in the tank 1 when the vehicle is stopped or running is charged to the main canister 2, and a gate valve 4 is provided on the inlet pipe 1a to be opened and closed by inserting and removing the fuel nozzle n. The second ventilation passage _l2 is connected to the upper space inside the tank 1 and connected to the sub-canister 5, so that the fuel vapor generated in the tank when refueling the tank 1 is charged to the sub-canister 5. The base end of the 2 ventilation passage _l2 protrudes into the upper space of the fuel tank 1, and a liquid level sensing valve V is attached thereto to close the passage opening when the liquid level rises due to refueling. The structure of the point is the same as that of the conventional one.

By the way, in this invention, as shown in FIG. 2, the liquid level sensing valve installed at the base end of the second ventilation passage _l2 protruding into the upper space within the fuel tank 1 is the main valve _v1 and this valve. The main valve _v1 is composed of a top-shaped main body 11a and a pipe part ₁ which also serves as a lid body.
1b, the main body 11a houses a convex main float 12 and a weight ball 13 in contact with a recess on its lower surface, and a conical ball seat 14 and a conical ball seat 14 on the bottom wall thereof. Multiple liquid holes 1
5 is provided.

On the other hand, the pipe portion 11b is provided with a plurality of horizontally elongated steam holes 16 and a tapered sheet surface 17 with an upper taper in sequence from below at a position directly above the lid body, and on one side of the upper part of the tapered sheet surface 17. A short bypass pipe 18 leading into the pipe section is installed horizontally,
At the tip of this bypass pipe 18, a valve body 19 of a sub-valve _V2 is vertically installed so as to be located above the main body 11a of the main valve _V1 , and inside the valve body 19 is a sub-float 20 and its lower surface. A weight ball 21 that comes into contact with is accommodated, and a plurality of through holes 22 are provided in the conical bottom wall,
A tapered sheet surface 23 is formed in a portion communicating with the bypass pipe 18 .

Based on the above configuration, when the fuel nozzle n is inserted into the inlet pipe 1a in order to refuel the fuel tank 1, the gate valve 4 on the inlet pipe is opened and the tank 1 is refueled.
Most of the fuel vapor generated in the main valve v ₁ passes through the oblong steam vent 16 as shown by the arrow, and a portion passes through the vent 22 of the sub valve v ₂ and the bypass pipe 18 to the second ventilator. The fuel enters the cylinder passage _l2 and is charged to the sub-canister 5.

Then, as the fuel level gradually rises, a part of the fuel enters the main body 1a through the liquid passage hole 15 of the main valve _v1 and pushes up the main float 12, and as the liquid level continues to rise, The main float 12 abuts against the tapered sheet surface 17 of the pipe portion 11b. In this state, the liquid level in the inlet pipe 1a rises due to the relationship between the amount of fuel supplied by the nozzle n and the amount of fuel vapor flowing out from the bypass pipe 18 (the speed is slower than that of the conventional type without a bypass, in other words (The more fuel is stored, the more fuel will be stored.) At a certain point, the nozzle tip senses the liquid level and stops refueling.

At that time, the secondary float 20 is not yet activated,
The bypass pipe 18 is open and the steam in the tank can flow out, and the waving fuel has calmed down due to the stoppage of refueling, and the liquid level in the inlet pipe 1a has decreased, making it possible to refuel. become a state.

When refueling, the fuel vapor in the upper part of the tank flows through the through hole 22 of the sub-valve v ₂ to the valve body 1.
9, passes through the bypass pipe 18 and flows out into the second ventilation passage _l2 , and when the liquid level in the tank and inlet pipe 1a gradually rises and the required amount of increased fuel has entered. The sub-float 20 operates and presses against the tapered sheet surface 23 to close the bypass pipe. Thereafter, the tip of the refueling nozzle n senses the liquid level in the inlet pipe 1a and stops refueling.

Figure 3 shows the above contents in a rough form. In the conventional system without a bypass pipe, the float closes the second ventilation passage at point a, which is considerably lower than the practical lower limit level line, but in this invention, First, the main float closes the ventilation passage at point b, which approaches the lower limit level line, and further closes the bypass pipe at point c, which exceeds the lower limit level line.

When the vehicle falls or tilts significantly, the weight balls 13 and 21 housed in the main valve body 11a and the sub-valve body 19 immediately push up the main float 12 and the sub-float 20, and the second ventilation The passage and the bypass pipe are closed in a locked state to prevent the fuel in the tank 1 from leaking to the outside.

(Effects of the invention) As described above, in this invention, as a valve device connected to the base end in the tank of the second ventilation passage that processes fuel vapor generated in the fuel tank during refueling in a vehicle, Connect the pipe section of the main valve to the base end of the ventilation passage,
This pipe section is provided with a tapered seat surface and a steam vent in sequence, and a bypass pipe that communicates with the inside is attached to the upper part of the tapered seat surface, and a secondary pipe is installed at the tip of the bypass pipe located above the main body of the main valve. The valve body of the valve is installed vertically, and a float and a weight ball are housed inside the main valve body and sub-valve body, respectively, so refueling is possible when refueling the fuel tank, and the amount of refueling is significantly reduced compared to conventional models. In addition, when the vehicle overturns or tilts significantly, the steam passage can be immediately locked and there is no risk of fuel inside the tank flowing outside and causing a fire.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a fuel vapor processing device using a valve device according to this invention. FIG. 2 is a sectional view of the valve device of this invention. Figure 3 is a rough diagram of the timing of float activation. FIG. 4 is a schematic side view of a conventional steam processing apparatus. In the figure, 1...Fuel tank, 2...Main canister, 4...Gate valve, 5...Sub-canister, 11a
... Main body, 11b ... Pipe section, 12 ... Main float, 13 ... Weight ball, 15 ... Liquid passage hole, 16 ... Steam hole, 17, 23 ... Tapered sheet surface, 18 ... Bypass pipe , 19...Valve body, 20...Sub-float, 21...Weight ball, _l2 ...Second ventilation passage, _v1 ...Main valve, _v2 ...Sub-valve.

Claims (1)

[Scope of utility model registration request] A valve device that is installed at the base end in the tank of a second ventilation passage that connects the upper space of the fuel tank to the canister via a gate valve on the inlet pipe, and that cuts off the flow of fuel vapor during refueling, A pipe section of a main valve consisting of a pot-shaped main body and a pipe section that also serves as a lid is connected to the base end of the second ventilation passage, and a tapered seat surface and a steam vent are sequentially provided in the pipe section. At the same time, a bypass pipe that communicates with the inside is attached at the top of the tapered seat surface, and the valve body of the sub-valve is placed vertically at the tip of the bypass pipe, positioned above the main valve body, and the main valve body and the sub-valve are connected to each other. A valve device for fuel vapor processing that houses a float and a weight ball inside the valve body.