JPS6218322A - Fuel cap - Google Patents

Abstract

PURPOSE:To prevent the vapor in a fuel tank from being discharged into the atmosphere, by installing a communication pipe which communicates to a canister for absorbing the vapor in the fuel tank and a seal receiving member closely attached with a sealing member, onto an oil feeding port of a fuel cap. CONSTITUTION:When fuel is supplied into a fuel tank 1, a cap part 12 is loosened, and the hook 19 of an opening/closing control value 9 which is restrained by a guide 18 is turned, and set at the uppermost part of the cam surface 20 of an outer cylinder part 11. Then, a gap having the distance H is formed between a seal receiving member 14 and the third sealing member 8, and the vapor in the fuel tank 1 is absorbed into a canister 6 through a space part 7 and a communication pipe 5. After a fuel cap body 3 is demounted, an oil feeding nozzle 21 is inserted into an oil feeding port 2, and oil is supplied, and then the fuel in the jet back due to the coil supply or vapor is absorbed onto the canister 6 from the communication pipe 5, passing through between a ventilation port 4, seal receiving member 14, and the nozzle 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel cap for a fuel filler port of a fuel tank for a vehicle, particularly for an automobile.

[Conventional technology]

Vehicles powered by internal combustion engines are usually equipped with a fuel tank, but when the fuel in the fuel tank runs low, the fuel cap that seals the fuel filler port of the fuel tank must be removed and the fuel filler nozzle inserted into the filler port. Insert and refuel. When the remaining amount of fuel in a fuel tank becomes low, the upper space inside the tank is filled with pressurized fuel vapor, so if you remove the fuel cap, these fuel vapors will be released into the atmosphere. and pollute the atmosphere.

Utility Model Application No. 103746/1983 discloses a fuel cap equipped with a pressure regulating valve that keeps the pressure inside the fuel tank constant, but it does not have a structure that adjusts the vapor pressure inside the fuel tank with the outside air. Therefore, it does not contribute to air pollution prevention.

[The problem that the invention attempts to solve]

The fuel cap of a conventional dual vehicle fuel tank is equipped with a pressure regulating valve that keeps the pressure inside the fuel tank constant, as in the device disclosed in Utility Model Application No. 103746/1983. This pressure adjustment is performed between the fuel tank and the outside air, so when the fuel vapor pressure in the tank increases, the fuel vapor is released to the outside air, which poses the problem of polluting the atmosphere. ing.

[Means for solving problems]

In the fuel cap of the fuel tank of the present invention, the fuel filler port includes an annular seal receiver that is in close contact with the lower end of the fuel cap main body on the lower side of the engaging means in the sealed state;
A space formed by the inner wall of the fuel filler port, the inner wall of the fuel cap body, and the lower part of the engagement means of the fuel cap body, and a communication pipe that communicates from the side of the fuel filler port in this space to the canister that absorbs vapor in the fuel tank. The fuel cap body includes a cap part, an outer cylinder part, and an on-off control valve fitted into the outer cylinder part, and the cap part includes means for holding the outer cylinder part and the on-off control valve, and a means for holding the on-off control valve. The outer cylindrical part is restrained by the guide part of the cap part and the open/close control valve, which wears out, is connected to the fuel tank between the cam surface, which slides as the cap part rotates, and the upper end of the fuel filler port. The opening/closing control valve includes a first sealing member that seals the steam inside the fuel tank, and a retaining means that engages with the fuel filler port. a negative pressure valve that sucks outside air; a second seal member that seals vapor in the fuel tank between a portion of the cap portion that is restrained by the guide means; and an outer cylinder portion; and a cap body that is in a sealed state. A thirteenth seal member is provided which is in close contact with the seal receiver of the fuel filler port and seals vapor in the fuel tank.

Therefore, when the vapor pressure in the fuel tank decreases, outside air is sucked into the tank by the negative pressure valve, and when the vapor pressure in the fuel tank increases and overcomes the biasing force of the spring of the fuel control valve, the vapor flows into the third tank. The fuel is absorbed into the canister through the communication pipe between the seal member and the seal holder, and when the remaining amount of fuel inside is low and needs to be refilled, turning the cap causes the opening/closing control valve to close to the cam's sliding surface. The gap between the third seal member and the seal receiver opens, and the steam passes through the communication pipe and is absorbed into the canister. After the steam pressure decreases, the cap is removed, so that the atmosphere caused by fuel vapor is removed. contamination is prevented.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a fuel tank equipped with an embodiment of the fuel cap of the present invention. A fuel filler port 2 is attached to the upper part of the fuel tank 1, and a fuel cap 3 is screwed onto the fuel filler port 2. A vent 4 is provided between the upper surface of the fuel tank 1 and the lower side of the seal receiver of the fuel filler port 4 to guide the blown back fuel and fuel vapor generated during fuel injection to the fuel filler port 2. There is. A space 7 formed by the seal receiver] 4, the inner wall of the fuel filler port 2, and the threaded portion 11 of the fuel cap 3, which communicates from the side surface on the fuel filler port 2 side to the canister 6, which contains activated carbon and absorbs fuel vapor. A tube 5 is provided.

Details of the vicinity of the fuel cap portion in FIG. 1 are shown in FIG. 2. The oil filler port 2 has an internal thread 15b and is screwed into an external thread 15a of the outer cylinder portion 11. A first seal member 10 is provided between the collar of the outer cylinder part 11 and the upper end of the fuel filler port 2, and a second seal member is provided between the outer cylinder part 11 and the on-off control valve 9], 6 is provided to seal between the fuel filler port 2 and the outside air,
The seal receiver 14 of the fuel filler port 2 and the third seal member 8 provided at the lower end of the opening/closing control valve 9 seal vapor in the fuel tank 1 when the fuel cap 3 is in a sealed state. A spring 18 is provided at the upper part of the inner diameter of the opening/closing control valve 9, which always urges it downward, and a negative pressure valve 17 is provided at the lower part, which is activated when the pressure in the fuel tank l decreases. There is.

The structure of the rotating and sliding portion of the fuel cap main body of this embodiment will be explained with reference to FIGS. 4a to 4d. The cap portion 12 has guides 1 at four locations that restrain the pawls 19 of the on-off control valve 9.
8 is provided, and the pawl 19 of the opening/closing control valve 9 rides on the cam surface 20 of the outer cylinder part 11, and its movement is controlled by the guide 18 of the cap part 12, and these three parts are illustrated in FIG. 4d. It is assembled like this.

If the amount of fuel remaining in the fuel tank l is low and needs to be replenished, turning the cap part 12 in the loosening direction releases the pawl 19 of the on-off control valve 9 restrained by the guide 18.
is rotated and slides on the cam surface 20 of the outer cylinder part 11 until approximately 9
It rotates 0° and reaches the top of the cam surface 20, which is H higher than the initial position shown in FIG. 4d. At this time 1. As shown in FIG. 3, a gap with a distance of H is created between the seal receiver 14 and the third seal member 8, and the steam inside the fuel tank 1 passes from this gap through the space 7 and the communication pipe 5. and is absorbed into the canister 6. During this time, the thread 15a of the outer cylinder portion 11 and the inner thread 151 of the fuel filler port 2 are not moving, so the first seal member 10 and the seal member 16 of i2 are functioning effectively. When the fuel cap main body 3 is further turned in the return direction, the pawl 19 of the on-off control valve 9
The fuel cap main body 3 is rotated in a direction in which the entire fuel cap body 3 is removed by hitting the protrusion at the top of the first cam.
The sealing member 10 stops working, but at that point the vapor pressure inside the fuel tank 1 decreases and does not pollute the atmosphere.

After removing the fuel cap body 3, remove the fuel nozzle 2.
1 into the oil filler port 2 to refuel, the stepped part of the refueling nozzle 21 is brought into close contact with the inlet end of the oil filler port 2 as shown in Fig. 5, thereby preventing the oil from spraying back. Fuel or steam passes between the vent 4, the seal receiver 14 and the nozzle z1, and is absorbed into the canister 6 from the communication pipe 5. When refueling is completed, the refueling nozzle 21 is pulled out, the fuel cap main body 3 is attached to the refueling port 2, and the external thread 15a on the cap side and the internal thread 15b on the refueling port are screwed together and tightened. As shown in FIG. 4d, the pawl 19 of the opening/closing control valve 9 is housed in the lowest part of the cam surface 20 of the outer cylinder part]l, and the third seal member 8 is in close contact with the seal receiver 14,
At the same time, the first seal member 10 performs a sealing action between the flange portion of the outer cylinder portion 11 and the upper end of the fuel filler port 2 .

Furthermore, when the fuel cap main body 3 is in a sealed state with respect to the fuel filler port 2, if the pressure inside the fuel tank 1 becomes negative pressure exceeding the limit of the spring force of the negative pressure pulp 17,
When the negative pressure valve 17 opens and sucks in outside air, the vapor pressure inside the fuel tank 1 increases and overcomes the spring force of the spring 13.
The spring 18 is compressed, and a gap proportional to the difference between the steam pressure and the atmospheric pressure is created between the seal receiver 14 and the third seal member 8, and the steam passes from the gap through the space 7 and the communication pipe 5 to the canister 6. is absorbed by the gas, and is closed when the pressure difference between the two falls within a certain limit.

Here, the fuel vapor absorbed into the canister 6 containing activated carbon is purged into an operating range set during vehicle operation.

〔Effect of the invention〕

As explained above, the present invention provides a fuel cap that engages with a refueling tank of a fuel tank, in which the refueling port has a communication pipe connected to a canister that absorbs vapor from the fuel tank below the engaging means, and further below the connecting pipe. A seal receiver is provided on the side, which is provided at the lowest end of the fuel cap and comes into close contact with a third seal member, and the fuel cap body is composed of a cap part, an outer cylindrical part, and an opening/closing control valve, and the cap part is turned in the loosening direction. Due to the cam action between the outer cylinder and the opening/closing control valve, a gap is created between the third seal member and the seal receiver, and the vapor in the fuel tank is absorbed into the canister through this gap. The steam inside the tank is not released into the atmosphere, which has the effect of preventing air pollution.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the structure of a fuel tank of an embodiment of the 7 fuel cap of the present invention, FIG. 2 is a cross-sectional view showing details of the fuel cap in a sealed state, and FIG. FIGS. 4a, b, and c are cross-sectional views showing a state in which the opening/closing control valve is lifted up by the cam action; FIGS. Figure d is a partially sectional front view showing the assembled state, and Figure 5 is a cross-sectional view showing the state in which fuel is being refilled after the fuel cap has been removed from the fuel filler port of the fuel tank. . 1... Fuel tank, 2... Fuel filler port, 3... Fuel cap body, 4... Ventilation pipe, 5... Communication pipe, 6... Canister, 7... Empty Interval part, 8...Third seal member, 9...Opening/closing control valve, 10...First seal member, 11...Outer cylinder part, 12...Cap part, 13... Spring, 14... Seal receiver, 15a... Outer thread, 15b... Inner thread, 16... Second seal member, 17... Negative pressure pulp, 18... Guide , 19...Claw, 20...Force/Mu face, 21...Refueling nozzle. Patent applicant Toyota Motor Corporation Agent Tadashi Wakabayashi W & 1 Figure 3 (a) (b) Figure 4 Figure 4 (c) (d) Figure 5 Procedural amendment (voluntary) April 1981 3 days

Claims (1)

[Scope of Claims] A fuel cap having means for engaging with a fuel filler port of a fuel tank, wherein the fuel filler port is in close contact with the lower end of the fuel cap main body below the engaging means in its sealed state. A space formed by an annular seal receiver, an inner wall of the seal receiver, the inner wall of the fuel filler port, and a lower portion of the engaging means of the fuel cap main body; the fuel cap body includes a cap portion, an outer cylindrical portion, and an on-off control valve fitted in the outer cylindrical portion, and the cap portion is connected to the on-off control valve. and a means for holding an outer cylinder part, and a guide means for restraining the opening/closing control valve, and the outer cylinder part is arranged such that the opening/closing control valve restrained by the guide means of the cap part follows rotation of the cap part. a first seal member that seals vapor in the fuel tank between a cam surface that slides along the cam surface and an upper end of the fuel filler port, and an engagement means that engages with the fuel filler port, and the opening/closing control valve is a spring that constantly urges downward,
a negative pressure valve that sucks in outside air when the pressure in the fuel tank decreases; a second valve that seals vapor in the fuel tank between a portion of the cap portion that is restrained by the guide means; and the outer cylinder portion; 1. A fuel cap comprising: a seal member; and a third seal member that is in close contact with the seal receiver of the fuel filler port when the cap body is in a sealed state, and seals vapor in the fuel tank.