JP3376828B2 - Fuel tank device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank device used in a vehicle, a ship, etc., and more particularly to an improvement in a portion for removing gas when refueling fuel.

[0002]

2. Description of the Related Art Conventionally, as this type, for example, there is one shown in FIG. Reference numeral 1 in the figure is a fuel tank of a vehicle, and a filler tube 3 is connected to a tank body 2.

The tank body 2 is provided with an evaporation side float valve 5 and a vent side float valve 6 on the upper surface 2a.

The evaporative side float valve 5 is connected to the canister 9 through the evaporative side tube 7, and the vent side float valve 6 is connected to the canister 9 through the vent side tube 8.

An evaporative side check valve 10 is provided in the middle of the evaporation side tube 7, and a vent side check valve 11 is provided in the middle of the vent side tube 8.

The vent-side check valve 11 has a diaphragm 11a and a first chamber 11b and a second chamber 11c.
The inflow side tube 8a and the outflow side tube 8b of the vent side tube 8 are exposed to the second chamber 11c, and the inflow side tube 8a and the outflow side tube 8b are opened or closed by opening and closing the diaphragm 11a. It has become. A signal tube 13 is provided between the first chamber 11b and the filler tube 3.

The canister 9 is open to the atmosphere through an opening 14 and is also connected to an engine side (not shown) via a tube 15.

With this structure, when refueling, the filler cap 3a of the filler tube 3 is opened, and the refueling nozzle N is inserted from the refueling port of the tube 3 as shown by the chain double-dashed line in the figure. Refuel. The fuel flows from the filler tube 3 into the tank body 2, and the vapor generated in the tank body 2 at this time is introduced into the canister 9 via the vent side check valve 11. That is, the pressure in the first chamber 11b via the signal tube 13 is the pressure in the filler tube 3, that is, the atmospheric pressure during the opening of the filler cap, while the pressure in the tank body 2 is the vaporized gas pressure and the inflow pressure of the fuel. Is higher than the atmospheric pressure. This opens the diaphragm 11a,
The vapor is guided to the canister 9 via the vent-side tube 8 to adsorb the fuel, and then the air is released to the atmosphere.
In this way, the gas inside the tank main body 2 is degassed, so that the fuel can be smoothly supplied.

Further, since the evaporative-side check valve 10 is set so as not to open unless the pressure is higher than the vent-side check valve 11, the evaporative-side check valve 10 is closed during refueling.

On the other hand, when the pressure in the tank body 2 rises above a certain value while the filler cap 3a is closed, the pressure in the filler tube 3 also becomes the same as the pressure in the tank body 2. Accordingly, the first chamber 11b of the vent side check valve 11 and the inflow side tube 8 of the vent side tube 8 are
Since the pressure is the same as a, the vent side check valve 1
1 maintains the closed state.

When the pressure in the tank body 2 rises to a certain set value when the vent side check valve 11 is closed, the evaporative side check valve 10 opens and the evaporative gas canisters through the evaporative side tube 7. Introduced in 9.

An example of this type is described in US Pat. No. 5,099,880.

[0013]

However, in such a conventional one, the upper end portion of the signal tube 13 connected to the filler tube 3 is caused by the vehicle turning such that the fuel is biased toward the filler tube 3 side. Fuel may enter the signal tube 13 from 13a, and in such a case, the operation of the vent side check valve 11 may be broken.

Therefore, an object of the present invention is to provide a fuel tank device which suppresses the infiltration of fuel into the signal tube.

[0015]

SUMMARY OF THE INVENTION The invention described in claim 1 has been made in view of the above problems, and a fuel tank is provided with a fuel tank, and a filler tube connected to the tank body to supply fuel. In the fuel tank device, wherein the tank main body is connected to the canister via a vent side check valve and guides gas in the tank main body to the canister via the vent side check valve when refueling, The side check valve has a diaphragm disposed in a case and is divided into a first chamber and a second chamber, the first chamber being connected to an upper portion of the filler tube by a signal tube, and the second chamber being an inflow tube. Is connected to the tank body, and is connected to the canister with an outflow side tube. An orifice is provided at the upper end of the filler tube side, and the orifice is a fuel tank device having an inner diameter and a length set so as to prevent fuel from entering the signal tube from the filler tube side. It has a feature.

According to such a construction, when the filler cap is closed, there is a possibility that fuel will infiltrate into the interior from the upper end of the signal tube due to vehicle turning or the like, according to the present invention. By forming an orifice set to the inner diameter and length at the upper end of the signal tube, it is possible to prevent fuel from entering into the signal tube through this orifice and maintain the function of the vent side check valve. .

In the invention described in claim 2, the fuel tank has a tank main body and a filler tube connected to the tank main body for supplying fuel, and the tank main body is provided with a canister via a vent side check valve. In the fuel tank device that is connected to the fuel tank device and guides the gas in the tank body to the canister through the vent side check valve at the time of refueling, the vent side check valve is
A diaphragm is provided in the case to define a first chamber and a second chamber, the first chamber is connected to an upper portion of the filler tube by a signal tube, and the second chamber is connected to a tank body by an inflow tube. At the same time, it is connected to the canister by an outflow side tube, and further, an air reservoir is provided in a portion of the filler tube to which the signal tube end is connected, and when the vehicle turns, the air in the air reservoir is By entering into the signal tube,
The fuel tank device is characterized in that it is set so as to prevent fuel from entering the signal tube.

According to this structure, when the filler cap is closed, conventionally, when the vehicle turns, or when the pressure in the tank body rises when the fuel reaches the upper end of the signal tube and the tank is full. However, there is a risk that fuel may enter the inside from the upper end of the signal tube. According to the present invention, such a situation is prevented by forming the air reservoir. That is, in such a case,
Since the air in the air reservoir instead of the fuel flows into the signal tube from the upper end of the signal tube, it is possible to prevent the fuel from entering.

According to a third aspect of the present invention, in addition to the structure of the second aspect, an upper end portion of the signal tube is
The feature is that an orifice is provided.

According to this construction, in addition to the effect of the second aspect, this orifice can prevent the infiltration of fuel into the upper end of the signal tube.

The invention described in claim 4 is the fuel tank device according to claim 1 or 2, wherein the orifice is formed in a fitting member fitted to the upper end portion of the signal tube. There is.

According to this structure, the orifice can be formed in the fitting member which is a separate member from the signal tube.
The inner diameter and length can be set relatively freely without being affected by the signal tube.

According to a fifth aspect of the present invention, an inclined opening is formed at the upper end of the circulation tube disposed adjacent to the signal tube so that the fitting member having the orifice cannot be fitted. Each claim 1
The fuel tank device described in 4 is featured.

According to this structure, the inclined opening formed at the upper end of the circulation tube disposed adjacent to the signal tube makes the fitting member having the orifice unfittable. Therefore, there is no possibility that the fitting member having the orifice is fitted to the upper end of the signal tube by mistake and assembled.

According to a sixth aspect of the present invention, the fitting member having the orifice and fitted to the upper end portion of the signal tube is in contact with the cylindrical body inserted into the filler tube. As a result, the fuel tank device according to each of claims 1 to 5 is characterized in that an opening holding projection for holding the orifice opening is formed by forming a predetermined gap.

According to this structure, even if the fitting member fitted to the upper end of the signal tube moves, the opening holding projection comes into contact with the cylindrical body, and the cylindrical body and the fitting member are contacted with each other. A predetermined gap is formed between the two, and the orifice opening is held. Therefore, the orifice opening is not blocked.

The invention according to claim 7 is the fuel tank device according to claim 6, wherein the opening holding projections are formed at three positions on the periphery of the orifice opening.

According to this structure, since the opening holding projections are formed at three positions on the peripheral edge of the orifice opening, the fitting member is brought into contact with the tubular body in a well-balanced manner without tilting, and the projections are held in all directions. A substantially uniform predetermined gap is formed.

[0029]

Embodiment 1 of the Invention Embodiments of the present invention will be described below.

1 to 7 show the first embodiment of the present invention.
Is shown.

First, the structure will be described. In FIG. 1, reference numeral 1 is a fuel tank of a vehicle, which is composed of a tank body 2 and a filler tube 3 connected thereto.

The tank body 2 is provided with an evaporation side float valve 5 and a vent side float valve 6 on the upper surface 2a.

The evaporation side float valve 5 is connected to the canister 9 via the evaporation side tube 7, and the vent side float valve 6 is connected to the canister 9 via the vent side tube 8.

An evaporation side check valve 10 is provided in the middle of the evaporation side tube 7, and a vent side check valve 11 is provided in the middle of the vent side tube 8.

In the vent-side check valve 11, a diaphragm 11a is provided in the case 11d along a substantially horizontal direction, and the inside of the case 11d is defined vertically, so that the first chamber 11b is provided above the diaphragm 11a. But again
The second chamber 11c is formed on the lower side, the inflow side tube 8a and the outflow side tube 8b of the vent side tube 8 are exposed to the second chamber 11c, and the inflow side tube 8a and the outflow side tube 8b are opened and closed by opening and closing the diaphragm 11a. It is designed to be connected or disconnected.

More specifically, the inflow side tube 8a is arranged vertically in the second chamber 11c of the case 11d, and the opening at the upper end is opened and closed by the diaphragm 11a. In the opened state, the inflow side tube 8a and the outflow side tube 8b communicate with each other. As shown in FIG. 1, a peripheral portion of the diaphragm 11a is attached to the case 11d, and the diaphragm 11a is biased downward by a coil spring (not shown).

On the other hand, a signal tube 13 is provided between the first chamber 11b and the filler tube upper portion 3b. The upper end 13 a of the signal tube 13 is connected to the upper portion 3 b of the filler tube 3, and the upper end 1 a
A fitting member 17 having an orifice 17a is mounted in 3a as shown in FIG.

The inner diameter φ and the length L of the orifice 17a
Is set so as to prevent fuel from entering the signal tube 13 from the filler tube 3 side.

The upper portion 2b of the tank body 2 and the upper portion 3b of the filler tube 3 are connected by a circulation tube 18. This circulation tube 18 has an upper end portion 18a on the filler tube 3 connection side.
However, as shown in FIG.
It is connected near 3a. Then, as shown in FIG. 4, the upper end portion 18a of the circulation tube is opened above the tip of the refueling nozzle N at the time of refueling, and the cut end is inclined so that the fitting member 1 is formed.
It has a slanted opening 18c that prevents the fitting of 7 into the fitting. In addition, as shown in FIG.
An orifice 18b is provided as shown in FIG. In FIG. 1, for the sake of clarity, the signal tube upper end 13a and the circulation tube upper end 18 are shown.
Although a and a are drawn apart from each other in the vertical direction, in reality,
As shown in FIG. 2 and FIG. 3, the heights are substantially the same and are separated in the lateral direction.

The orifice 18b is designed to limit the circulation amount of the vapor circulated from the tank body 2 into the filler tube 3 through the circulation tube 18, and the vapor circulation amount at the time of refueling. The negative pressure of the fuel inflow is set so as not to be larger than the suction amount of the gas flowing into the tank body 2.

Furthermore, the upper part 3 of this filler tube 3
A cylindrical body 19 is inserted and arranged in b. That is, as shown in FIGS. 3 and 4, the tubular body 19 has a flange portion 19a formed at the upper end thereof so as to be hooked on the end edge of the filler tube upper portion 3b, and at the lower side thereof. The sealing agent 20 is filled over the entire circumference between the filler tube upper portion 3b and the inner circumferential wall. This filling position is near the upper side of the connection position of the upper ends 13a and 18a of the signal tube 13 and the circulation tube 18. Further, the lower portion 19b of the tubular body 19 is gradually thinned.

As a result, an air reservoir 21 is formed between the filler tube upper portion 3b and the tubular body 19 at the connection portion of the signal tube upper end portion 13a, so that the air in the air reservoir 21 can be changed when the vehicle turns. Are set to prevent the fuel from entering the signal tube 13 by entering the signal tube 13.

Assuming that the volume of the signal tube 13 is V2, the body pressure is P1, and the cap valve opening pressure is P2, the volume V1 in the air reservoir 19 is V1 ≧ V2 × (P2 / P1) (1) (1) ( It is set so as to satisfy the expression (1).

Here, the cap valve opening pressure is the valve opening pressure of the degassing mechanism that is provided in a filler cap (not shown) and that acts when the abnormal internal pressure rises.

The lower portion 19b of the tubular body 19 allows
A “guide means” is configured to guide the vapor circulated from the circulation tube 18 into the filler tube 3 downward in the filler tube 3.

On the other hand, the outflow side tube 8b of the vent side tube 8 has an inner diameter of 13 mm, and this outflow side tube 8b
An orifice 22 having an inner diameter of 6 mm is arranged inside. The orifice 22 prevents the vapor at the time of refueling from coming out to the canister 9 side so that the vapor in the tank body 2 is easily circulated to the filler tube 3 side through the circulation tube 18.

The canister 9 is open to the atmosphere through the opening 14 and is connected to the engine side through the tube 15.

Next, the operation will be described.

First, when refueling, the filler cap of the filler tube 3 is opened, and the refueling nozzle N is inserted from the refueling port of this tube 3 as shown in FIG. Fuel flows from the filler tube 3 to the tank body 2
A part of the vapor flowing into the inside of the tank body 2 at this time is introduced into the canister 9 through the vent side check valve 11. That is, the signal tube 13
Through the first chamber 11b through the pressure in the filler tube 3,
That is, while the filler cap is open, it is at atmospheric pressure, but inside the tank main body 2, it is higher than atmospheric pressure due to the inflow pressure of fuel. As a result, the diaphragm 11
a is displaced upward against the urging force of the coil spring to open the inflow side tube 8a and the outflow side tube 8b.
The vapor is guided to the canister 9 via the, and after the fuel is adsorbed, the air is released to the atmosphere. In this way, the gas inside the tank main body 2 is degassed, so that the fuel can be smoothly supplied.

At the time of refueling, the vapor in the tank body 2 flows into the canister 9 side and is circulated in the filler tube 3 through the circulation tube 18 at the same time as described above. The inflow position of the vapor into the filler tube 3 is above the tip of the refueling nozzle N, and this part is a part where a negative pressure is produced when fuel is injected from the refueling nozzle N. Therefore, the vapor from the circulation tube 18 is circulated by re-flowing into the tank body 2 through the filler tube 3 together with the fuel. As a result, when refueling, the amount of outside air drawn from the atmosphere into the filler tube 3 can be reduced, and as a result, the amount of vapor flowing into the canister 9 via the vent side check valve 11 can be reduced. It is possible to reduce the size of the canister 9.

Further, the circulation tube 18
The vapor circulated in the filler tube 3 from the inside of the tubular body 19 is guided to the lower side of the filler tube 3 at the lower portion 19b, so that the circulation performance is improved, and the vapor containing this fuel component is The air will not be released from the tube 3 to the atmosphere, and the inclusion of outside air will be further suppressed.

Furthermore, since the orifice 22 is provided in the outflow side tube 8b, the vapor in the tank body 2 is hard to come out to the canister 9 side at the time of refueling, and is circulated from the circulation tube 18 to the filler tube 3 side. By increasing the amount of vapor, it is possible to further suppress the amount of vapor generated in the tank body 2.

Moreover, the circulation tube 18
By providing the orifice 18b in this, the amount of vapor circulated from this tube 18 to the side of the filler tube 3 does not become larger than the amount of gas sucked into the tank body 2 due to the negative pressure of the fuel inflow at the time of refueling. Therefore, the circulated vapor will not be released to the atmosphere.

Then, when the fuel is supplied to the full tank of the tank body 2, the float 6a of the vent side float valve 6 rises, the opening 6b is closed, and the inflow side tube 8 is closed.
The fuel is prevented from flowing into a and the lower end of the circulation tube 18 is also immersed in the fuel.
As a result, the fuel is accumulated up to the upper portion 3b of the filler tube 3 with the air layer being secured in the tank body 2.

On the other hand, with the filler cap closed,
When the pressure in the tank body 2 rises above a certain value, the pressure in the filler tube 3 also becomes the same as the pressure in the tank body 2. Thereby, the first check valve 11 of the vent side is
Since the chamber 11b and the inflow side tube 8a of the vent side tube 8 have the same pressure, the vent side check valve 11 maintains the closed state.

Further, conventionally, when the pressure in the tank main body 2 rises when the vehicle is turning or when the fuel reaches the signal tube upper end portion 13a in a full tank, the inside of the signal tube upper end portion 13a is increased. Although there is a risk that fuel may enter, such a situation can be prevented by providing the air reservoir 21 and the orifice 17a at the upper end 13a of the signal tube.

That is, by providing the air reservoir 21, the air in the air reservoir 21 enters the signal tube 13a before the fuel enters the signal tube upper end 13a, and the air reservoir 21 Since the volume is set as described above, even if the pressure in the tank body 2 rises to the cap valve opening pressure P2, the fuel does not enter the signal tube 13.

Further, by providing the orifice 17a having a predetermined inner diameter φ and a predetermined length L at the upper end portion 13a of the signal tube, even if the fuel jumps up due to vehicle turning or the like, the orifice 17a is provided inside the orifice 17a. Even if some fuel enters, it does not pass through the orifice 17a and enter the signal tube 13.
The fuel that has entered the orifice 17a to some extent is then evaporated or is sucked into the filler tube 3 side by the negative pressure during refueling, and is removed from the orifice 17a.

Since the fuel can be prevented from entering the signal tube 13 in this way, the vent side check valve 1
The function 1 can be normally maintained.

On the other hand, while the vehicle is running, the evaporative side check valve 10 is set to open at a pressure higher than the valve opening pressure of the vent side check valve 11 at the time of refueling. When the filler cap is closed, the same internal pressure acts on both sides of the diaphragm 11a, so the closed state is maintained even if the pressure in the tank body 2 rises, and the evaporative-side check valve 10 reaches its set value. After the opening, the evaporation gas is introduced into the canister 9 via the evaporation side tube 7.

Further, according to the first embodiment, since the air reservoir 21 and the guide means can be constructed only by disposing the tubular body 19, the structure can be simplified.

Further, in the first embodiment, as shown in FIG. 4, the circulation tube upper end portion 18a is formed above the tip of the refueling nozzle N at the time of refueling, and the cut end is inclined. Since it has the inclined opening 18c, the upper end portion 18a of this circulation tube
In addition, there is no possibility that the fitting member 17 is erroneously fitted and assembled.

Furthermore, since the fitting member 17 is a member separate from the signal tube 13, the inner diameter φ and the length L of the orifice are not affected by the signal tube 13 (however, it is necessary that the inner diameter φ and the length L of the orifice are within the inner diameter of the signal tube 13). However, it can be set relatively freely.

Therefore, even if the conditions such as the refueling performance are different, it is only necessary to replace the fitting member 17 without replacing the signal tube 13.

[0065]

EXAMPLE Here, the inner diameter φ and the length L1 of the orifice 17a in the upper end portion 13a of the signal tube are determined as follows.

That is, as shown in FIG. 5, when the orifice 17a is inserted into and removed from the gasoline 20 times, the relationship between the inner diameter φ of the orifice 17a and the penetration length L2 of gasoline into the orifice 17a is measured. The data is shown in Figure 6.
The graph is as shown in. It can be seen from the characteristic curve A of the actual measurement value of this measurement data that the penetration length L2 is 1 mm when the inner diameter φ of the orifice 17a is, for example, 1 mm. The inner diameter φ and the length L1 of the orifice 17a are determined based on this data. However, if the safety factor is set to double so that gasoline does not enter the signal tube 13, as shown in the characteristic curve B, , Orifice 1
When the inner diameter φ of the 7a is 1 mm, the length L1 of the orifice 17a should be set to 2 mm. As a result of confirming with an actual filler tube 3, when the inner diameter φ of the orifice 17a is 1.5 mm and the length L1 is 4 mm, the infiltration amount of gasoline into the filler tube 3 is 0 cc, the inner diameter φ is 2.0 mm, It was confirmed that when the length L of the orifice 17a was 4 mm, the amount of gasoline infiltrated into the signal tube 13 was 2 cc. Therefore, it was proved that the above measurement data is effective as data when determining the inner diameter φ and the length L1 of the orifice 17a.

Further, the circulation tube 1
The inner diameters φ of the orifice 18b of No. 8 and the orifice 22 of the vent side tube 8 are determined as follows.

In other words, if the relationship between the amount of air entrained and the amount of vapor produced when 1 liter of gasoline is supplied,
The characteristic curve C shown in FIG. 7 is obtained. Further, if the relationship between the internal pressure of the tank body 2 and the air entrainment amount is shown, characteristic curves D, E, F, G shown in FIG. 7 are obtained. This is because the inner diameter φ of the orifice 18b of the circulation tube 18 is
The solid line characteristic curve D is 2.5 mm, the broken line characteristic curve E is 2.7 mm, the one-dot chain line characteristic curve F is 3.0 mm, the two-dot chain line characteristic curve G is 3.5 mm, and the outflow tube The inner diameter of the orifice 22 of 8b is from 6 mm to a large size.

As is clear from the characteristic curve C, it is understood that the vapor generation amount is reduced by decreasing the air entrainment amount. Therefore, from the characteristic curves D, E, F and G, it is possible to know what inner diameter φ the orifices 18b and 22 are set to make the air entrainment amount zero. However, when the inner diameter φ is set so that the air entrainment amount becomes zero, the filler tube 3 is inserted through the circulation tube 18.
There is a risk that the amount of vapor circulated inside will become too large and this vapor will be diffused from the filler tube 3 to the atmosphere. Therefore, it is desirable to set the inner diameters of the orifices 18b and 22 based on the characteristic curves D, E, F, and G so that the air entrainment amount is slightly larger than zero. Further, if the pressure in the tank main body 2 is made too high, it becomes difficult for fuel to flow into the tank main body 2, so the inside of the tank main body 2 may be set within the range of 5 mmHg to 25 mmHg.

[0070]

Second Embodiment FIGS. 8 and 9 show a second embodiment of the present invention. In addition, the same or equivalent portions as those in the first embodiment will be described with the same reference numerals.

In the fuel tank device according to the second embodiment, the fitting member 117 having the orifice 17a and fitted to the upper end portion of the signal tube 13 is provided.

In this fitting member 117, as shown in FIG. 9, the flat-faced concave portion 19c formed on the side surface of the tubular body 19 is brought into contact with the tubular body-facing surface 119 of the front side flange portion 118 to form a tubular shape. Between the body 19 and the fitting member 117, opening holding protrusions 120, 120 that form a predetermined gap are formed.

The opening holding projections 120, 120 have a pair of semi-circular arc shapes which are concentrically formed around the opening of the orifice 17a.

Next, the operation of the second embodiment will be described.

In the fuel tank device according to the second embodiment, the fitting member 117 fitted to the upper end portion 13a of the signal tube 13 is arranged in the direction shown in FIG. Even if the opening holding protrusions 120 and 120 are moved as indicated by the dashed line,
Abutting on the planar recess 19c of the cylindrical body planar recess 1
A predetermined gap 1 is formed between 9c and the fitting member 117, and the opening of the orifice 17a is held. Therefore, the opening of the orifice 17a does not come into close contact with the flat concave portion 19c and is not blocked.

Moreover, in the second embodiment, since the flat recess 19c can be formed on the side surface of the cylindrical body 19, the space efficiency is good and the capacity of the air reservoir 21 is set to be large. You can

The other structure and operation are substantially the same as those in the first embodiment, and the description thereof will be omitted.

FIG. 10 shows a fitting member 217 used in the fuel tank device according to the third embodiment of the present invention.

As shown in FIG. 10, in this fitting member 217, the flat face recessed portion 19c formed on the side surface of the tubular body 19 is brought into contact with the tubular body facing surface 219 of the front flange portion 218, and Between the body 19 and the fitting member 217, three opening holding protrusions 220 ... Forming a predetermined gap are formed.

The opening holding projections 220 ... Are formed in a substantially concentric shape with the opening of the orifice 17a as the center.

Next, the operation of the third embodiment will be described.

In the fuel tank device according to the third embodiment, in addition to the effects of the first and second embodiments, the opening holding projections 220 ... Are further formed at three locations around the orifice opening. , The fitting member 217
However, when it moves in the extraction direction and comes into contact with the planar concave portion 19C, all the opening holding projections 220 ...
A predetermined uniform gap 1 is formed in all directions.

The other structure and operation are substantially the same as those of the first and second embodiments, and the description thereof will be omitted.

[0084]

As described above, according to the invention described in claim 1, when the filler cap is closed, conventionally, the fuel intrudes into the inside from the upper end of the signal tube due to vehicle turning or the like. However, according to the present invention, an orifice having a predetermined inner diameter and a predetermined length is formed at the upper end of the signal tube to prevent fuel from entering the signal tube through the orifice. Therefore, the function of the check valve on the vent side can be maintained.

According to the second aspect of the present invention, by providing the air reservoir at the portion where the upper end of the signal tube is connected, when the vehicle is turning or the fuel reaches the upper end of the signal tube, the tank is full. It is possible to prevent fuel from entering from the upper end of the signal tube to the inside when the pressure in the tank body rises in this state.

According to the invention described in claim 3, in addition to the effect of claim 2, by providing an orifice at the upper end of the signal tube, in addition to the effect of claim 2, the signal It is possible to prevent fuel from entering the upper end of the tube.

According to the invention described in claim 4, since the orifice can be formed in the fitting member which is a separate member from the signal tube, the inner diameter and the length thereof can be set relatively freely without being influenced by the signal tube. it can.

According to the invention described in claim 5, the inclined opening formed at the upper end of the circulation tube disposed adjacent to the signal tube cannot fit the fitting member having the orifice. And For this reason,
There is no possibility that the fitting member having the orifice is fitted to the upper end of the signal tube by mistake and assembled.

According to the invention described in claim 6, even when the fitting member fitted to the upper end portion of the signal tube moves, the opening holding projection comes into contact with the cylindrical body, A predetermined gap is formed between the fitting member and the fitting member, and the orifice opening is held. Therefore, the orifice opening is not blocked.

According to the invention described in claim 7, since the opening holding projections are formed at three positions on the peripheral edge of the orifice opening, the fitting member does not tilt and contacts the cylindrical body in good balance. In contact with each other, a practically useful effect of forming a substantially uniform predetermined gap in all directions is exhibited.

[Brief description of drawings]

FIG. 1 is a schematic view of a fuel tank device showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a signal tube and a circulation tube are connected to the filler tube showing the embodiment.

FIG. 3 is a cross-sectional view of a filler tube of a signal tube connection portion showing the same embodiment.

FIG. 4 is a cross-sectional view of a filler tube in a circulation tube connection portion showing the same embodiment.

FIG. 5 is an explanatory diagram showing a state in which a relationship between an inner diameter of an orifice and a penetration length of gasoline into the orifice is measured, showing the embodiment.

FIG. 6 is a graph showing a relationship between an inner diameter of an orifice and a penetration length of gasoline into the orifice, showing the embodiment.

FIG. 7 is a graph showing a relationship between an air entrainment amount, a vapor generation amount, and a tank main body internal pressure, showing the embodiment.

FIG. 8 is a cross-sectional view of a filler tube of a signal tube connecting portion showing the second embodiment.

FIG. 9 is a perspective view of a fitting member showing the same embodiment.

FIG. 10 is a perspective view of a fitting member according to the second embodiment.

FIG. 11 is a schematic diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

1 Fuel tank 2 tank body 3 filler tubes 8 Vent side tube 8a Inlet tube 8b Outflow tube 9 canister 11 Vent side check valve 11a diaphragm 11b Room 1 11c Room 2 11d case 13 Signal tube 13a upper end 17a Orifice 21 Air trap

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-323204 (JP, A) JP-A-8-326610 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02M 37/00 301 B60K 15/04 F02M 25/08

Claims (7)

(57) [Claims] 1. A fuel tank has a tank main body and a filler tube connected to the tank main body for supplying fuel, the tank main body is connected to a canister via a vent side check valve, and at the time of refueling fuel, In the fuel tank device for guiding the gas in the tank main body to the canister through the vent side check valve, the vent side check valve has a diaphragm arranged in a case and is defined in a first chamber and a second chamber. , The first chamber is connected to the filler tube upper part by a signal tube, the second chamber is connected to the tank body by an inflow side tube, and is connected to the canister by an outflow side tube, further, An orifice is provided at the upper end portion on the filler tube side, and the orifice is the filler channel. From over Bed side to prevent entry of fuel into the signal in the tube, the fuel tank system, characterized in that the inner diameter and length are set. 2. A fuel tank has a tank main body and a filler tube connected to the tank main body to supply fuel, the tank main body is connected to a canister via a vent side check valve, and at the time of fuel supply, In the fuel tank device for guiding the gas in the tank main body to the canister through the vent side check valve, the vent side check valve has a diaphragm arranged in a case and is defined in a first chamber and a second chamber. , The first chamber is connected to the upper part of the filler tube by a signal tube, the second chamber is connected to the tank body by an inflow side tube, and is connected to the canister by an outflow side tube, and further, , An air reservoir is provided at a portion to which the end portion of the signal tube is connected, and the empty space is provided when the vehicle turns. By air in reservoir enters the said signal tube, fuel tank and wherein the set so as to prevent the ingress of fuel into the signal tube. 3. The fuel tank device according to claim 2, wherein an orifice is provided at an upper end portion of the signal tube. 4. The fuel tank device according to claim 1, wherein the orifice is formed in a fitting member fitted to an upper end portion of the signal tube. 5. An inclined opening is formed at an upper end portion of a circulation tube disposed adjacent to the signal tube so that a fitting member having the orifice cannot be fitted thereto. The fuel tank device according to claim 1. 6. The fitting member, which has the orifice and is fitted to the upper end portion of the signal tube, is brought into contact with a cylindrical body inserted into the filler tube,
An opening holding projection for holding the orifice opening by forming a predetermined gap is formed.
5. The fuel tank device according to item 5. 7. The fuel tank device according to claim 6, wherein the opening holding projections are formed at three locations on the periphery of the orifice opening.