JPH07332171A - Canister - Google Patents

Abstract

PURPOSE:To prevent outflow of vapor from an outside air introducing port while the engine is at a standstill for a long period of time besides oil filling. and shorten the time for oil filling and decrease the vapor flow-out amount to the atmosphere from the oil filling hole when the oil filling takes place. CONSTITUTION:A part from a vapor introducing port 27, an oil filling vapor introducing port 28 in communication with the air chamber part 35a of a fuel tank 35 is furnished on the main chamber side 4, 5. Furthermore, an atmospheric releasing port 30 is provided on the main chamber side 4, 5 apart from an outside air introducing port 31 located on the aux. chamber 15 side. Normally closed opening/closing valves 38, 44 are furnished at the oil filling vapor introducing port 28 and atmospheric releasing port 30 and are opened when the oil is to be supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canister for treating evaporated fuel generated from a fuel storage tank such as a fuel tank so as not to release it into the atmosphere.

[0002]

2. Description of the Related Art Conventionally, there is a canister as shown in FIG. 10 for processing evaporated fuel (hereinafter referred to as vapor) generated from a fuel tank of an automobile.

In FIG. 10, 101 is a canister body, and the interior of the casing is defined by a partition wall 104 to form a main chamber 102.
And sub-chamber 103, and these chambers are filled with a main adsorbent 105 and a sub-adsorbent 106 made of activated carbon or the like. Reference numerals 107 and 108 denote filters disposed above and below the main adsorbent 105, and 109 and 110 denote filters disposed above and below the sub-adsorbent 106. 111 is the first diffusion chamber, 11
Reference numeral 2 is a second diffusion chamber, 113 is a third diffusion chamber, 114 is a fourth diffusion chamber, and 115 is a communication hole that connects the second diffusion chamber 112 and the third diffusion chamber 113. Reference numeral 116 is a throttle ventilation hole that connects the third diffusion chamber 113 and the sub chamber 103.

In the canister thus constructed, the vapor generated in the fuel tank 118 is removed from the main adsorbent 10 through the vapor passage 117 while the engine is stopped.
5. The vapor collected in the main adsorbent 105 is sucked into the intake passage 120 through the barge passage 119 due to the negative pressure generated in the intake passage 120 having the throttle valve 121 when the engine is driven. To do.

Further, when the vapor adsorbed and collected by the main adsorbent 105 diffuses while the engine is stopped for a long time, the vapor diffuses into the second diffusion chamber 112 and the communication hole 115.
Through the third diffusion chamber 113, and further squeeze vent holes 116
Through which the vapor is adsorbed and collected by the sub-adsorbent 106, and the air is discharged from the atmosphere introduction port 122 to the atmosphere.

An evaporative fuel treatment system equipped with such a canister is described, for example, in FIG. 1 of JP-A-5-33734.

[0007]

In the above conventional canister, when the ventilation area of the throttle ventilation hole 116 is set to be small, the ventilation resistance from the main chamber 102 to the sub chamber 103 becomes large, and the engine is stopped for a long time. In this case, the vapor can be prevented from being discharged from the atmosphere introducing port 122 to the atmosphere, but on the other hand, the air discharged by the vapor pressure generated by the vapor in the fuel tank 118 at the time of refueling is discharged from the fuel tank to the main chamber 102. Since the air is discharged through the sub chamber 103 through a long flow path to the atmosphere introduction port 122, and the throttle ventilation hole 116 suppresses the ventilation amount, the flow resistance of the air increases. Therefore, the air pressure in the fuel tank 118 becomes high and the refueling time becomes long. Further, the high air pressure and the long refueling time cause a problem that the amount of vapor flowing out from the refueling port to the atmosphere increases.

On the contrary, the throttle ventilation hole 1 to the sub chamber 103
When the ventilation area of 16 is set to be large, the ventilation resistance from the main chamber 102 to the main chamber 103 is reduced, the refueling time is shortened, and the outflow amount of vapor from the refueling port is reduced,
On the other hand, when the engine is stopped for a long time, the main chamber 102
The amount of vapor diffused into the sub chamber 103 increases,
In the worst case, there is a problem that vapor is released from the atmosphere introduction port 122 to the atmosphere. In order to solve this problem, it is necessary to make the sub chamber 103 large, and the canister becomes large.

Therefore, an object of the present invention is to provide a canister capable of solving the above problems.

[0010]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems by providing a main chamber (4, 5) and an auxiliary chamber (15) containing an adsorbent (11, 23) therein. Main room (4
A vapor introducing port (27) communicating with the air chamber portion of the fuel storage tank and a purge port (29) are provided on the 5) side, and the sub chamber (1
An air introduction port (31) is provided on the 5) side, and the main chamber (4,
5) and the auxiliary chamber (15) are communicated with each other through the vent holes (26), the main chamber (4, 5) side is communicated with the air chamber part of the fuel storage tank separately from the vapor introducing port (27). An air release port (30) is provided separately from the refueling vapor introduction port (28) and the air introduction port (31), and the refueling vapor introduction port (28) and the air release port (30) are normally opened and closed. Closed open / close valve (38, 38a,
44, 44a) and both of the on-off valves are opened during refueling.

[0011]

[Function] The open / close valves (38, 38a, 44, 44a) are closed except when fuel is being supplied to the fuel storage tank such as the fuel tank (35), and the vapor is removed from the main chamber (4,5) in the canister (1). Since it circulates in the sub chamber (15) and also in the throttle ventilation hole (26), the ventilation resistance of the air containing vapor increases.
Therefore, when the vapor adsorbed by the main adsorbent (11) in the main chamber (4,5) is left for a long time without being purged, the vapor adsorbed by the main adsorbent (11) diffuses. If done, the vapor's sub-chamber (15)
Outflow is suppressed. This means that the outflow of vapor from the air introduction port (31) can be suppressed, and this suppression makes the sub-chamber (15) of a small capacity so that the sub-adsorbent (1
5) can be made small.

When refueling, the on-off valves (38, 38a,
44, 44a) is opened, air containing vapor flows through the main chambers (4,5), and the throttle ventilation holes (26) and the sub chambers (1).
5) It flows out from the atmosphere opening port (30) without flowing through the inside. Therefore, the ventilation resistance becomes smaller than that described above, the air pressure generated in the fuel storage tank such as the fuel tank (35) is quickly discharged from the atmosphere opening port (30), and the air pressure in the fuel storage tank is increased. Is suppressed. At this time, the vapor is mainly adsorbed by the main adsorbent (11) in the main chambers (4,5), and only air is discharged from the atmosphere opening port (30). At this time, the air pressure in the fuel storage tank is reduced, and the refueling time is shortened. Further, since the air pressure is reduced and the refueling time is shortened, the amount of vapor discharged from the refueling port to the atmosphere is reduced.

[0013]

EXAMPLE An example shown in FIGS. 1 to 6 in which the present invention is used as a canister for adsorbing evaporated fuel generated from a fuel tank of an automobile will be described below.

First, referring to FIGS. 2 and 3, the structure of the canister will be described in detail. Reference numeral 1 denotes a canister body, and a casing 2 constituting the canister body has a rectangular tubular shape in plan view as shown in FIGS. 2 and 3. A main chamber (main canister) is formed in the casing 2, and the main chamber is composed of a first main chamber 4 and a second main chamber 5 which are partitioned by a partition plate 3 in the central portion. The partition plate 3 is formed to have a length that does not reach the bottom of the first main chamber 4 and the second main chamber 5, and the two main chambers 4 and 5 are communicated with each other by a communication hole 6 at the bottom.

Holding plates 7 and 8 made of perforated plates are installed on the top and bottom of the first main chamber 4 and the second main chamber 5, and filters 9 and 10 are arranged on the inner surface side of the plates 7 and 8. ing. A main adsorbent 11 made of activated carbon or the like is filled between the filters 9 and 10.

The upper plate 7 in the first main chamber 4 section
A first diffusion chamber 12 is formed on the upper side of the second main chamber 5 and a third diffusion chamber 13 is formed on the upper side of the upper plate 7 in the second main chamber 5 part. It is partitioned into a non-communication state.

Below the lower plate 8 in the first main chamber 4 and the second main chamber 5, the second lower surface of the both main chambers 4 and 5 extends over the entire lower surface.
A diffusion chamber 14 is formed. Reference numeral 15 denotes a sub-chamber (sub-canister), which is located at the center of the second main chamber 5 and is formed by providing a cylindrical partition plate 16 and is partitioned from the second main chamber 5. Reference numeral 17 denotes a vapor flow passage, which is formed by partitioning a part of the sub chamber 15 with a partition plate 18.

Holding plates 19 and 20 made of perforated plates are installed on the upper and lower parts of the sub chamber 15, and the plate 1
Filters 21 and 22 are arranged on the inner surface sides of 9 and 20. A sub-adsorbent 23 made of activated carbon or the like is filled between the filters 19 and 20.

A fourth diffusion chamber 24 is formed below the lower plate 20 in the sub chamber 15, and an upper plate 19 is formed.
A fifth diffusion chamber 25 is formed on the upper side of the. The upper portion of the vapor flow passage 17 communicates with the third diffusion chamber 13 through the throttle ventilation hole 26. The opening area of the throttle vent hole 26 is such that the vapor adsorbed on the main adsorbent 11 is not released from the air introduction port 31 and left in the auxiliary adsorbent 23 when the engine is left for a long time except when the engine is stopped. The opening area is set so that it can be adsorbed and collected by. The lower part of the vapor flow passage 17 communicates with the fourth diffusion chamber 24.

Numeral 27 is a vapor introducing port communicating with the first diffusion chamber 12, 28 is an oil supply vapor introducing port communicating with the first diffusion chamber 12, and 29 is a purge port communicating with the first diffusion chamber 12.

Reference numeral 30 is an atmosphere opening port communicating with the third diffusion chamber 13 on the second main chamber 5 side, and 31 is an atmosphere introducing port communicating with the fifth diffusion chamber 25 on the sub chamber 15 side. The second diffusion chamber 14 has a bottom plate 32 at the lower end opening of the casing 2.
And the fourth diffusion chamber 24 is formed by welding the bottom plate 3
A cover 33 is provided on the inner surface of the second member 2 so as to be separated from the second diffusion chamber 14.

Next, a first embodiment of an evaporated fuel processing apparatus using the above canister will be described with reference to FIG. The vapor introduction port 27 communicates with the air chamber portion 35a of the fuel tank 35 mounted on the vehicle through the first vapor passage 34. A pressure valve 36 is provided in the first vapor passage 34. The pressure valve 36 includes a check valve 36a that opens when the pressure inside the fuel tank 35 becomes a positive pressure equal to or higher than a predetermined pressure.
A check valve 36b that opens when the inside of the fuel tank 35 becomes a negative pressure below a predetermined pressure, and introduces the vapor into the canister 1 when the vapor inside the fuel tank 35 becomes above a predetermined pressure. In addition, the fuel tank 35 is prevented from being damaged due to abnormal positive pressure or negative pressure.

The refueling vapor introducing port 28 passes through the second vapor passage 37 and the air chamber portion 35 of the fuel tank 35.
It is connected to a. The second vapor passage 37 is provided with a normally closed opening / closing valve 38 which is an electromagnetic valve.

The purge port 29 has a purge passage 39.
Through a negative pressure port 41 opening to an intake passage 40 to the engine. 42 indicates a throttle valve. The atmosphere opening port 30 is open to the atmosphere through a passage 43, and the passage 43 is provided with a normally closed opening / closing valve 44 which is an electromagnetic valve.

The atmosphere introducing port 31 is open to the atmosphere as it is. Double-sided on-off valve 38,4 consisting of the solenoid valve
The coil No. 4 is connected to the switch 46 by the wiring 45, and when the switch 46 is turned on, the current of the vehicle-mounted battery 47 is passed through the coil to open both the on-off valves.

The switch 46 is installed so as to be turned on / off in association with the attachment / detachment of the filler cap 48 in the filler tube 35b of the fuel tank 35, and is turned on when the filler cap 48 is removed from the filler tube 35 during refueling. When it is fitted, it is turned off.

Next, the operation of the first embodiment will be described. When the engine is stopped except when fuel is being supplied to the fuel tank 35, the filler cap 48 is fitted in the filler tube 35b, so the switch 4
6 is turned off, the coils of both on-off valves (electromagnetic valves) 38 and 44 are not energized, both on-off valves 38 and 44 are closed, and the refueling vapor introduction port 28 and the atmosphere opening port 30 are closed. Therefore, when the air pressure in the fuel tank 35 rises above a predetermined level, the check valve 36a of the pressure valve 36 is opened by the air pressure. Due to this opening operation, the pressure difference between the pressure of the air containing the vapor and the atmospheric pressure of the atmosphere introduction port 31 of the canister 1 causes the fuel tank 3
The vapor in 5 is introduced into the first diffusion chamber 12 from the vapor introduction port 27 in the canister 1 through the first vapor passage 34 together with air.

The air containing the introduced vapor is
As shown by the arrow in FIG. 4, the main adsorbent 11 in the first main chamber 4
Layer, the second diffusion chamber 14, the layer of the main adsorbent 11 in the second main chamber 5, the third diffusion chamber 13, the throttle ventilation hole 26, the vapor flow passage 1
7, the fourth diffusion chamber 24, the layer of the sub-adsorbent 23 in the sub-chamber 15, the vapor component thereof is adsorbed and collected by each adsorbent 11, 23, the air is discharged from the atmosphere introduction port 31 to the atmosphere. It As described above, by passing through the long path and passing through the throttle vent hole 26, the flow resistance of the vapor is increased, the efficiency of vapor adsorption to the main adsorbent 11 in the main chamber 4 is increased, and the air is introduced into the atmosphere. The amount of vapor discharged from the port 31 is reduced.

Next, when the engine is driven with the filler cap 48 fitted, the negative pressure in the intake passage 40 changes from the negative pressure port 41 to the purge passage 39 and the purge port 2.
9 to act in the first diffusion chamber 12. In this case, since the on-off valves 38 and 44 are closed, the atmosphere is introduced from the atmosphere introducing port 31 on the side of the sub chamber 15, and the atmosphere is opposite to that shown in FIG. 4 as indicated by the arrow in FIG. It circulates through the passage and is sucked into the intake passage 40 through the purge passage 39. As a result, the vapor adsorbed by the main adsorbent 11 and the sub-adsorbent 23 is sucked and discharged into the intake passage 40 together with the atmosphere.

Next, at the time of refueling, when the filler cap 48 of the fuel tank 35 is removed, the switch 46 is turned on, the coils of both on-off valves (solenoid valves) 38, 44 are energized from the battery 47, and the on-off valve 38 is opened. , 44 are opened to bring the refueling vapor introducing port 28 and the atmosphere opening port 30 into a flow state.

Therefore, when the air pressure in the fuel tank 35 rises due to refueling, the air containing vapor flows into the first diffusion chamber 12 through the refueling vapor introducing port 28 due to the differential pressure from the atmospheric pressure of the atmosphere opening port 30. Then, as shown by the arrow in FIG. 6, it flows from the first main chamber 4 into the second main chamber 5 through the second diffusion chamber 14 and the communication passage 6, and flows into the atmosphere opening port 30 through the third diffusion chamber 13, The vapor component is collected and adsorbed by the main adsorbent 11, and the air flows out from the atmosphere opening port 30 to the atmosphere.

At the time of this circulation, as compared with the flow other than that at the time of refueling shown in FIG. 4, since the circulation path is short because it does not circulate in the sub chamber 15 and the circulation does not flow through the throttle ventilation hole 26, Distribution resistance is reduced. As a result, the air pressure generated in the fuel tank 35 at the time of refueling can be quickly discharged, the pressure increase in the fuel tank 35 is suppressed, and the refueling time is shortened. Further, by suppressing the pressure increase in the fuel tank and shortening the refueling time as described above, the amount of vapor flowing from the filler tube 35b to the atmosphere at the time of refueling can also be reduced.

The partition plate 3 is provided in the main chamber 4 so that the vapor flowing into the main chamber is not immediately discharged from the atmosphere opening port 30, that is, the partition plate 3 allows the main chamber of the vapor to be discharged. 4, the flow path in the main adsorbent 11 is lengthened so that the amount of vapor adsorbed to the main adsorbent 11 is increased.

7 to 9 show a second embodiment of the present invention, in which the solenoid valves of the first embodiment are used as the opening / closing valves 38, 4
Instead of 4, an on-off valve with a pressure valve is used.
An on-off valve 38a, which replaces the on-off valve 38, has a structure shown in FIG. The on-off valve 38a is divided into a first chamber 52 and a second chamber 53 by a diaphragm 51 in the case 50, and the first chamber 52 is provided with the above-mentioned fuel by a port 54 and a vapor passage 37a as shown in FIG. It communicates with the tank 35. A valve portion 51a is integrally formed on the central upper surface of the diaphragm 51, and the valve portion 51a is connected to the port 5a.
5, the diaphragm 55 opens downward to open the port 55 and moves upward to close the port 55. Reference numeral 56 denotes a spring, which constantly urges the valve portion 51a of the diaphragm 51 in the closing direction. The urging force is such that the pressure in the first chamber 52 is higher than the pressure in the second chamber 53 and the differential pressure thereof is When the pressure reaches approximately 30 mmAq, the valve portion 51a is set to open due to the pressure difference. As shown in FIG. 7, the port 55 communicates with the refueling vapor introducing port 28 of the canister 1 by a vapor passage 37b. As shown in FIG. 7, the second chamber 53 communicates with the inside of the filler tube 35b near the filler cap 48 in the fuel tank 35 through the port 57 and the communication passage 58.

An on-off valve 44a which replaces the on-off valve 44 is shown in FIG.
It has the structure shown in. The opening / closing valve 44a includes a diaphragm 51, a first chamber 52, a second chamber 52
It has a chamber 53, a port 54, a spring 56 and a port 57. Further, there is a third chamber 61 in which a port 59 and a port 60 are opened, the valve portion 51a provided on the diaphragm 51 faces the port 60, the downward movement of the diaphragm 51 opens the port 60, and the upward movement causes the port 60 to open. It is designed to block 60. Then, as shown in FIG. 7, the port 54 communicates with the vapor passage 37b, the port 57 communicates with the communication passage 58, the port 59 communicates with the atmosphere opening port 30 in the canister 1, and the port 6
0 is open to the atmosphere.

The other structure is similar to that of the first embodiment. Next, the operation of the second embodiment will be described. Since the pressure in the air chamber portion 35a of the fuel tank 35 and the pressure in the filler tube 35b are substantially equal to each other except when the filler cap 48 is fitted and the fuel is being filled, the double opening / closing valve 38
The pressure in the first chamber 52 in a and 44a and the pressure in the second chamber 53 communicating with the filler tube 35b are substantially equal. Therefore, the valve portion 51a closes the ports 55 and 60 by the urging force of the spring 56. As a result, when the engine is stopped for a long time except during refueling, the flow is as shown in FIG. 4 as in the first embodiment.

Next, at the time of refueling with the filler cap removed, the air pressure in the air chamber portion 35a of the fuel tank 35 rapidly rises due to refueling. This air pressure slightly flows out to the atmosphere through the gap of the opening on the atmosphere side of the filler tube 35b, but since the amount of pressure increase due to refueling is larger than this outflow, a large positive pressure is generated in the first chamber 52 of the on-off valve 38a. To work.

On the other hand, the pressure near the opening on the atmosphere side in the filler tube 35b becomes close to the atmospheric pressure due to the removal of the filler cap 48, and this pressure passes through the communication passage 58 to the second opening of the on-off valve 38a. It acts in the chamber 53. Therefore, the high positive pressure in the first chamber 52 and the second
Due to the pressure difference between the chamber 53 and the pressure close to the atmospheric pressure, the diaphragm 51 moves downward against the urging force of the spring 56,
The valve portion 51a is opened and the port 55 is opened.

When the port 55 of the on-off valve 38a is opened, the pressure in the first chamber 52 acts on the inside of the first chamber 52 of the other on-off valve 44a through the vapor passage 37b. Therefore, similar to the on-off valve 38a, the valve portion 51 of the on-off valve 44a.
a is also opened, and the atmosphere opening port 30 is opened to the atmosphere through the port 59, the third chamber 61 and the port 60. As a result, similarly to the first embodiment, the pressure increase in the fuel tank 35 during refueling can be suppressed, the refueling time can be shortened, and the amount of vapor flowing from the filler tube to the atmosphere can be reduced.

The second embodiment is characterized in that it does not require the power source as in the first embodiment and can be manufactured at a low cost with a simple structure. Although the on-off valves 38, 44, 38a, 44a in both of the above embodiments are provided separately from the canister 1, the on-off valves may be provided integrally with each port portion of the canister 1.

In the above embodiment, the present invention is shown as an example of a canister for processing evaporated fuel generated from a fuel tank of an automobile, but the canister of the present invention is generated from a fuel storage tank other than the fuel tank of the automobile. It may be used as a canister for processing the evaporated fuel that is used.

[0042]

As described above, according to the present invention,
When the engine is stopped and left for a long time except when refueling, the ventilation resistance in the canister can be increased to reduce the amount of vapor flowing out from the atmosphere introduction port.
At the time of refueling, the ventilation resistance in the canister is reduced to suppress the increase in air pressure generated in the fuel storage tank, and the refueling time can be shortened and the amount of vapor flowing out of the refueling port into the atmosphere is reduced. be able to.

Further, the capacity of the sub chamber having the atmosphere introducing port can be reduced to reduce the size of the canister.

[Brief description of drawings]

FIG. 1 is a diagram showing an evaporated fuel processing apparatus provided with a canister showing a first embodiment of the present invention.

FIG. 2 is a plan view showing a canister body of the present invention.

3 is a sectional view taken along line AA of FIG.

FIG. 4 is a diagram showing a flow of vapor other than during refueling.

FIG. 5 is a diagram showing the flow of air during purging.

FIG. 6 is a diagram showing the flow of air during refueling.

FIG. 7 is a view showing an evaporated fuel processing apparatus including a canister showing a second embodiment of the present invention.

8 is a vertical cross-sectional view of the on-off valve 38a of FIG.

9 is a vertical cross-sectional view of the on-off valve 44a of FIG.

FIG. 10 is a view showing a conventional canister and a vaporized fuel processing apparatus thereof.

[Explanation of symbols]

1 ... Canister 4,5 ... Main chamber 11,23 ... Adsorbent
15 ... Sub-chamber 26 ... Throttling ventilation hole 27 ... Vapor introduction port 28 ... Lubrication vapor introduction port 29 ... Purge port 30 ... Atmosphere release port 31 ... Atmosphere introduction port 3
8, 38a, 44, 44a ... Open / close valve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02M 37/00 H

Claims (1)

[Claims] 1. A main chamber and a sub chamber containing an adsorbent are provided,
In the main chamber side, a vapor introducing port communicating with the air chamber part of the fuel storage tank and a purge port are provided, an air introducing port is provided on the sub chamber side, and the main chamber and the sub chamber are communicated through a vent hole, In addition to the vapor introduction port, an oil supply vapor introduction port that communicates with the air chamber of the fuel storage tank and an atmosphere release port that is separate from the atmosphere introduction port are provided on the main chamber side, and the oil supply vapor introduction port and the atmosphere are opened. A canister, comprising a normally closed on-off valve for opening and closing a port, wherein both of the on-off valves are opened during refueling.