JP3372679B2 - Evaporative fuel processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporative fuel treatment system for preventing evaporative fuel generated during refueling of a fuel tank of a vehicle from being released to the atmosphere.

[0002]

2. Description of the Related Art A conventional evaporated fuel processing apparatus of this type is disclosed in U.S. Pat. No. 4,714,172.
This is such that a diaphragm valve (pressure response valve) is interposed between a fuel tank having a fuel supply pipe and a canister that adsorbs evaporated fuel generated in the fuel tank, and the first pressure chamber of the diaphragm valve is A second pressure chamber of the diaphragm valve, the second pressure chamber having an inlet communicating with the fuel tank and an outlet communicating with the canister, the pressure inlet communicating with a pressure outlet provided near the inlet of the fuel supply pipe. Have.

When the inlet of the fuel supply pipe is closed by the cap, the pressures in the first and second pressure chambers of the diaphragm valve become equal to each other, and the diaphragm valve maintains the closed state. On the other hand, when the cap is removed from the inlet of the fuel supply pipe during refueling, the pressure in the second pressure chamber decreases to atmospheric pressure, the diaphragm valve opens, and the evaporated fuel generated in the fuel tank is removed. It is introduced into the canister and adsorbed by an adsorbent (not shown) in the canister to prevent the vaporized fuel from being released to the atmosphere.

[0004]

However, in the above-mentioned conventional device, when the liquid fuel flows into the second pressure chamber of the diaphragm valve and accumulates due to some reason, the diaphragm of the diaphragm valve is not satisfied. There is a possibility that the pressure of the liquid fuel acts on the diaphragm, the diaphragm does not operate normally, and the diaphragm valve does not open.

In order to prevent this, as shown in FIG. 10, one end portion (fuel supply port portion) of a fuel supply pipe 5 provided in a fuel tank 4 is installed in a pressure inlet 3 of a second pressure chamber 2 of a diaphragm valve 1. It is conceivable that a part of the pressure passage 8 communicating with the pressure outlet 7 provided near 1a is mounted horizontally. In FIG. 10, 9 is a first pressure chamber of the diaphragm valve 1, which is connected to a canister 11 via an evaporated fuel passage 10. Further, the first pressure chamber 9 of the diaphragm valve 1 is
It communicates with the upper inside of the fuel tank 4 through the passage 12.
A float valve 13 is provided in the communication section. Also,
Reference numeral 14 denotes the first pressure chamber 9 and the second pressure chamber 2 of the diaphragm valve 1.
It is a diaphragm that isolates the valve from the valve and is biased in the valve closing direction by a spring 15. Further, 16 is a passage that connects the inside of the fuel tank 4 and the canister 11 to each other, and a switching valve 17 is provided in the passage 16. Further, reference numeral 18 is a pressure introducing port formed in the peripheral side wall of the fuel supply pipe 5 located inside the fuel tank 4, and the pressure introducing port 18 allows the pressure in the fuel tank 4 and the fuel The pressure inside the supply pipe 5 is constantly the same.

However, even if it is constructed as shown in FIG.
Liquid fuel accumulates in the second pressure chamber 2 of the diaphragm valve 1 (in FIG. 10, the shaded portion shows the accumulated liquid fuel).

The present invention has been made in view of the above-mentioned problems of the above-mentioned prior art, and its object is to prevent liquid fuel from accumulating in the second pressure chamber of the pressure response valve. Another object of the present invention is to provide an evaporated fuel processing device.

[0008]

In order to achieve the above object, an evaporated fuel processing apparatus according to claim 1 of the present invention adsorbs a fuel tank having a fuel supply pipe and evaporated fuel generated in the fuel tank. A first pressure chamber having a canister, an evaporated fuel passage communicating the canister with the fuel tank, an inlet provided in the middle of the evaporated fuel passage and communicating with the fuel tank, and an outlet communicating with the canister. When a second pressure chamber having inlet pressure outlet communicating with intake pressure provided around the entrance of the fuel supply pipe, the first
The pressure chamber and the second pressure chamber are isolated from each other and normally
The outlet communicating with the canister is closed by the biasing means.
In adult Ru evaporative fuel processing system and a pressure responsive valve provided with the biased diaphragm so that, the with a pressure-responsive valve provided at a high position from the pressure outlet, the pressure inlet of the second pressure chamber It is characterized in that it is provided at the lowest part of.

Further, in order to achieve the above object, the present invention
The evaporated fuel processing apparatus according to claim 2 , wherein a fuel tank having a fuel supply pipe, a canister for adsorbing the evaporated fuel generated in the fuel tank, and an evaporated fuel passage communicating between the canister and the fuel tank are provided. A first pressure chamber, which is provided in the middle of the fuel vapor passage and has an inlet communicating with the fuel tank and an outlet communicating with the canister, and a pressure outlet provided near the inlet of the fuel supply pipe. A second pressure chamber having a pressure inlet, and the first pressure chamber and the front
The second pressure chamber is isolated from each other, and normally used as a biasing means.
To close the outlet communicating with the canister.
In adult Ru evaporative fuel processing system and a pressure responsive valve provided with the energized been diaphragm, the inflow of liquid fuel and intake the pressure and the pressure outlet to the second pressure chamber in the middle of the pressure passage communicating The liquid fuel shutoff means for shutting off is provided.

In order to achieve the above object , the present invention
According to a third aspect of the present invention, there is provided the vaporized fuel processing device according to the second aspect.
In the fuel-emission processing device, the liquid fuel cutoff means is
Note that the chamber is located higher than the pressure outlet.
And are characterized by. Furthermore, the above-mentioned object is achieved.
For this reason, the evaporated fuel processing apparatus according to claim 4 of the present invention is a contractor.
The fuel vapor processing apparatus according to claim 2, wherein the liquid fuel
The shutoff means is a float valve.
is there.

[0011]

[0012]

[0013]

[0014]

[0015]

Embodiments of the present invention will be described below with reference to FIGS.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of an evaporated fuel processing apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 20 denotes a fuel tank, which is a fuel pipe communicating with the inside of the fuel tank 20 (fuel supply). Tube 21. The fuel pipe 21 has one end (upper end) 21a, which is a fuel supply port, protruding outward of the fuel tank 20 in an inclined state and the other end (lower end) 21b opening inside the fuel tank 20. ing. One end 2 of the fuel pipe 21
A pressure outlet 22 is provided near 1a. Inside the one end 21a of the fuel pipe 21, a normally-closed shutter valve (not shown) that is opened by inserting a fuel gun (not shown) is provided. A diaphragm valve (pressure responsive valve) 23 is provided at a position higher than the pressure outlet 22 on the outside of the fuel pipe 21.

The diaphragm valve 23 has a valve casing 24, and a first pressure chamber 26 and a second pressure chamber 27 isolated by the diaphragm 25 are provided in the valve casing 24. In the diaphragm valve 23, the operating axis L1 of the diaphragm 25 is inclined by a predetermined angle θ1 in the counterclockwise direction in the figure with respect to the vertical axis L2, and the axis L3 of the fuel pipe 21.
It is arranged in a state of being orthogonal to. First pressure chamber 26
Is communicated with the inside of the fuel tank 20 via the first evaporated fuel passage 28, and the second evaporated fuel passage 2
It communicates with the canister 30 via 9. One end of the first evaporative fuel passage 28 opens at the lowermost portion of the peripheral side wall of the valve casing 24 (the lowest portion of the first pressure chamber 26) and serves as an inlet 31 of the first pressure chamber 26. Further, one end of the second evaporated fuel passage 29 penetrates the peripheral side wall of the valve casing 24 in a liquid-tight manner and opens on the operating axis L1 of the diaphragm 25 to serve as an outlet 32 of the first pressure chamber 26. This outlet 32 is the diaphragm 25
It is opened and closed by a valve element 33 fixed to the central part of the. In the diaphragm 25, the spring 34 provided in the second pressure chamber 27 causes the valve element 33 to close the outlet 32 (valve closing direction).
Is urged by.

The second pressure chamber 27 communicates with the pressure outlet 22 of the fuel pipe 21 via the pressure passage 35. One end of the pressure passage 35 is located at the lowest part of the second pressure chamber 27 and is opened in the peripheral side wall of the valve casing 24 so as to be located in the second pressure chamber 27.
Of the pressure inlet 36. The opening axis line L4 of the pressure intake port 36 is set to be inclined by a predetermined angle θ2 in the counterclockwise direction in the figure with respect to the horizontal axis line L5.

The canister 30 communicates with the inside of the fuel tank 20 through a passage 37. Fuel tank 20
The canister 30 is connected to an engine (not shown). The canister 30 has an adsorbent for adsorbing the evaporated fuel, adsorbs the evaporated fuel generated in the fuel tank 20, and appropriately purges the adsorbed fuel in the intake system of the engine. In FIG. 1, 38 and 39 are the first fuel vapor passage 28.
And a float valve 40 provided in the fuel tank 20 so as to open and close the opening of the passage 37 on the fuel tank 20 side.
Is a switching valve interposed in the middle of the passage 37, and 41 is a cap that closes the one end 21a of the fuel pipe 21. Reference numeral 42 denotes a pressure inlet port formed in the peripheral side wall of the fuel supply pipe 21 located inside the fuel tank 20. The pressure inlet port 42 allows the pressure in the fuel tank 20 to be different from the pressure inside the fuel tank 20 at the time other than refueling. The pressure inside the fuel supply pipe 21 is constantly the same.

Next, the operation of the fuel vapor processing apparatus of this embodiment having the above-mentioned structure will be described.

One end 21a of the fuel pipe 21 when not refueling
The shutter valve inside is closed, the pressures in the fuel tank 20, the fuel pipe 21, the first pressure chamber 26 and the second pressure chamber 27 of the diaphragm valve 23 become equal, and the diaphragm valve 23 is closed. Stay in the state.

On the other hand, at the time of refueling, when the cap 41 is removed, the pressure in the vicinity of the pressure outlet 22 drops to atmospheric pressure. As a result, during refueling, the second pressure chamber 27 of the diaphragm valve 23 is
The pressure inside the first pressure chamber 26 becomes lower than the pressure inside the first pressure chamber 26, and the valve body 33, which is integrated with the diaphragm 25, is displaced in one direction against the urging force of the spring 34 to open the outlet 32 (valve open state). )become. As a result, a large amount of the evaporated fuel generated in the fuel tank 20 passes through the passage 28, the first pressure chamber 26 and the passage 2.
It is supplied to the canister 30 via 9 and adsorbed by the adsorbent.

By the way, when the fuel flows from the fuel tank 20 side into the fuel pipe 21 and a water head is generated, for example, when the fuel tank 20 is filled with fuel or when the vehicle is turning, the diaphragm 25 of the diaphragm 25 is closed. The reversing operation by pressure, the volume of the fuel pipe 21 and the second of the diaphragm valve 23
Only the amount of pressure change that is added to the volume of the pressure chamber 27,
From the pressure outlet 22 through the pressure passage 35 to the second pressure chamber 2
Fuel flows into 7. However, in the evaporative fuel processing system of this embodiment, the diaphragm valve 23 has the pressure outlet port 2.
2, the pressure inlet 36 of the second pressure chamber 27 is provided at the lowest portion of the second pressure chamber 27, so that the fuel that has flowed into the second pressure chamber 27 has a pressure inlet 36.
Since it returns from the pressure passage 35 to the inside of the fuel pipe 21 through the pressure passage 35, fuel does not accumulate in the second pressure chamber 27.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the evaporated fuel processing apparatus according to the second embodiment of the present invention. In FIG. 2, the same parts as those in FIG. 1 of the first embodiment described above are designated by the same reference numerals. is there. 2 is different from FIG. 1 in the mounting posture of the diaphragm valve 23. That is, the diaphragm valve 23 in the present embodiment is provided at a position higher than the pressure outlet 22 on the outer side of the fuel pipe 21, and the operating axis L1 of the diaphragm 25 is horizontal. One end of the pressure passage 35 is located on one end side of the lowest portion of the second pressure chamber 27 and opens on the peripheral side wall of the valve casing 24 to serve as a pressure inlet 36 of the second pressure chamber 27. . The pressure inlet 36 may be provided at any position within the range of the arrow θ3 in FIG.

The rest of the configuration and operation of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram showing a main configuration of an evaporated fuel processing apparatus according to a third embodiment of the present invention. In FIG. 3, the same parts as those of the first embodiment shown in FIG.
The same reference numerals are attached. 3 is different from FIG. 1 in the mounting posture of the diaphragm valve 23. That is,
The diaphragm valve 23 in this embodiment is the fuel pipe 2
It is located at a position higher than the pressure outlet 22 on the outer side of 1 and the operating axis L1 of the diaphragm 25 thereof is vertical. One end of the pressure passage 35 is located at the center of the lowest part of the second pressure chamber 27 and opens to the peripheral side wall of the valve casing 24 to serve as a pressure inlet 36 of the second pressure chamber 27. The pressure inlet 36 may be provided at any position within the range of the arrow θ4 in FIG.

The rest of the configuration and operation of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the structure of an evaporated fuel processing apparatus according to a fourth embodiment of the present invention. In FIG. 4, the same parts as those in FIG. 1 of the first embodiment described above are designated by the same reference numerals. is there. 4 is different from FIG. 1 in the attached state of the diaphragm valve 23. That is, the diaphragm valve 23 in this embodiment is integrally provided outside the fuel pipe 21. In this diaphragm valve 23, a part of the valve casing 24 is constituted by a peripheral side wall of the fuel pipe 21, and the pressure intake port 22 of the fuel pipe 21 is directly communicated with the pressure intake port 36 of the second pressure chamber 27 of the diaphragm valve 23. There is.

The rest of the configuration and operation of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a configuration of a main part of an evaporated fuel processing apparatus according to a fifth embodiment of the present invention, in which the same parts as those of the first embodiment shown in FIG.
The same reference numerals are attached. 5 is different from FIG. 1 in the attached state of the diaphragm valve 23. That is,
The diaphragm valve 23 in this embodiment has a valve casing 24.
The whole is attached inside the fuel pipe 21. The pressure inlet 36 of the second pressure chamber 27 of the diaphragm valve 23 is open to the inside of the fuel pipe 21, and the inlet 31 of the first pressure chamber 26 is the first to be inserted into the fuel pipe 21.
Is communicated with the inside of a fuel tank (not shown) via the evaporated fuel passage 28. The passage 29 is the fuel pipe 21.
Located outside of.

The rest of the configuration and operation of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a main part configuration of an evaporated fuel processing apparatus according to a sixth embodiment of the present invention. In FIG. 6, the same parts as those in FIG.
The same reference numerals are attached. 6 is different from FIG. 1 in the attached state of the diaphragm valve 23. That is,
The diaphragm valve 23 in this embodiment has a valve casing 24.
The half on the second pressure chamber 27 side is attached inside the fuel pipe 21, and the half on the first pressure chamber 26 side is attached inside the fuel pipe 21. And diaphragm valve 2
The pressure inlet 36 of the second pressure chamber 27 of No. 3 is the fuel pipe 21.
It has an opening inside. First evaporated fuel passage 28 and passage 2
9 is located outside the fuel pipe 21.

The rest of the configuration and operation of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Seventh Embodiment) Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing a main configuration of an evaporated fuel processing apparatus according to a seventh embodiment of the present invention. In FIG. 7, the same parts as those of the first embodiment shown in FIG.
The same reference numerals are attached. 7 is different from FIG. 1 in that the diaphragm valve 23 is attached, the pressure inlet 36 of the second pressure chamber 27 is disposed, and the liquid fuel to the second pressure chamber 27 is provided in the middle of the pressure passage 35. That is, the liquid fuel cutoff means for cutting off the inflow of the liquid is provided. That is, in this embodiment, the diaphragm valve 23 is arranged at a position lower than the pressure intake port 22 of the fuel pipe 21, and the pressure intake port 36 of the second pressure chamber 27 is provided on the upper surface of the second pressure chamber 27. A chamber 43 is provided near the pressure outlet 22 of the passage 35 as a liquid fuel cutoff means.

Even if the fuel flows from the pressure outlet 22 of the fuel pipe 21 into the pressure passage 35 for some reason, the fuel flows into the chamber 43, so that the second pressure of the diaphragm valve 23 is increased. It does not flow into the chamber 27. It should be noted that by providing the pressure outlet port 22 at an upper position in the drawing of the peripheral side wall of the fuel pipe 21 as shown in the drawing, it becomes difficult for fuel to flow out from the pressure outlet port 22 when the vehicle turns.

Since the other construction and operation of this embodiment are the same as those of the above-mentioned first embodiment, the description thereof will be omitted.

(Eighth Embodiment) Next, an eighth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing a configuration of essential parts of an evaporated fuel processing apparatus according to an eighth embodiment of the present invention. In FIG. 8, the same parts as those of FIG. 7 of the seventh embodiment described above are
The same reference numerals are attached. 8 is different from FIG. 7 in that a float valve 44 is provided as a liquid fuel cutoff means near the pressure outlet 22 of the pressure passage 35.

Even if the fuel flows from the pressure outlet 22 of the fuel pipe 21 into the pressure passage 35 for some reason, the float valve 44 is closed by the action of the fuel as shown in the drawing. Fuel does not flow into the second pressure chamber 27 of the diaphragm valve 23.

The rest of the configuration and operation of this embodiment are the same as those of the above-mentioned seventh embodiment, so a description thereof will be omitted.

(Ninth Embodiment) Next, a ninth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a diagram showing a configuration of a main part of an evaporated fuel processing apparatus according to a ninth embodiment of the present invention, in which the same parts as those of the seventh embodiment shown in FIG.
The same reference numerals are attached. 9 is different from FIG. 7 in that the chamber 43 is removed from the configuration of FIG. 7, and instead, a portion of the pressure passage 35 near the pressure outlet 22 is simply raised in an inverted U shape, and the rising portion 35a is raised. It is used as a liquid fuel cutoff means.

In FIG. 9, H indicates the vertical height from the pressure outlet 22 to the top of the rising portion 35a.
H'denotes the height from the pressure outlet 22 to the top of the rising portion 35a in the direction orthogonal to the liquid level (virtual) LF when the vehicle turns.

[0042]

As described in detail above, according to the fuel vapor processing apparatus of the first aspect of the present invention, the liquid fuel flowing out from the pressure inlet of the fuel supply pipe passes through the pressure inlet of the pressure response valve. Even if the liquid fuel flows into the second pressure chamber of the pressure responsive valve, the liquid fuel returns from the pressure inlet to the fuel supply pipe through the pressure outlet of the fuel supply pipe. Fuel does not collect.

Further, according to the fuel vapor processing apparatus of the second aspect of the present invention, when the liquid fuel flows out from the pressure outlet of the fuel supply pipe, the liquid fuel shuts off the liquid fuel in the middle of the pressure passage. The liquid fuel is not accumulated in the second pressure chamber of the pressure responsive valve because it is shut off by the above and does not flow into the second pressure chamber of the pressure responsive valve.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an evaporated fuel processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a main part configuration of an evaporated fuel processing apparatus according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of main parts of an evaporated fuel processing apparatus according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an evaporated fuel processing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a main configuration of an evaporated fuel processing device according to a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a main configuration of an evaporated fuel processing apparatus according to a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a main configuration of an evaporated fuel processing apparatus according to a seventh embodiment of the present invention.

FIG. 8 is a diagram showing a main configuration of an evaporated fuel processing device according to an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a main configuration of an evaporated fuel processing apparatus according to a ninth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a conventional evaporated fuel processing device.

[Explanation of symbols]

20 fuel tank 21 Fuel pipe (fuel supply pipe) 21a One end of fuel pipe (inlet) 22 Pressure outlet 23 Diaphragm valve (pressure response valve) 26 First pressure chamber 27 Second pressure chamber 30 canisters 31 Inlet of first pressure chamber 32 Outlet of first pressure chamber 35a Start-up part (liquid fuel cutoff means) 43 chamber (liquid fuel cutoff means) 44 Float valve (liquid fuel cutoff means)

Front page continuation (72) Inventor Masaaki Horiuchi 1-4-1 Chuo, Wako-shi, Saitama Inside of Honda R & D Co., Ltd. (56) Reference JP-A-7-224728 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02M 25/08 F02M 37/00 301

Claims (4)

(57) [Claims] 1. A fuel tank having a fuel supply pipe, a canister for adsorbing evaporated fuel generated in the fuel tank, an evaporated fuel passage communicating between the canister and the fuel tank, and an intermediate portion of the evaporated fuel passage. A first pressure chamber having an inlet communicating with the fuel tank and an outlet communicating with the canister, and a pressure inlet communicating with a pressure outlet provided near the inlet of the fuel supply pipe. Two pressure chambers , the first pressure chamber and the second pressure chamber are isolated from each other, and
An outlet that normally communicates with the canister by urging means
In adult Ru evaporative fuel processing system and a pressure responsive valve provided with the biased diaphragm so as to close, the pressure responsive valve is provided on the high position from the pressure outlet, wherein the pressure inlet second An evaporative fuel processing device, which is provided at the lowest part of a pressure chamber. 2. A fuel tank having a fuel supply pipe, a canister for adsorbing the evaporated fuel generated in the fuel tank, an evaporated fuel passage connecting the canister and the fuel tank, and an intermediate portion of the evaporated fuel passage. A first pressure chamber having an inlet communicating with the fuel tank and an outlet communicating with the canister, and a pressure inlet communicating with a pressure outlet provided near the inlet of the fuel supply pipe. Two pressure chambers , the first pressure chamber and the second pressure chamber are isolated from each other, and
An outlet that normally communicates with the canister by urging means
In adult Ru evaporative fuel processing system and a pressure responsive valve provided with the biased diaphragm to close and to the way the second pressure chamber of the pressure passage communicating the inlet the pressure and the pressure outlet And a liquid fuel cutoff means for cutting off the inflow of the liquid fuel. 3. The evaporative fuel treatment apparatus according to claim 2, wherein the liquid fuel cutoff means is a chamber provided at a position higher than the pressure outlet. 4. The evaporative fuel treatment apparatus according to claim 2, wherein the liquid fuel cutoff means is a float valve.