JP2003314380A - Evaporation fuel separating equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a separation membrane for condensing evaporation fuel from being exposed to droplet such as the fuel and water for a long period in an evaporation fuel separating equipment. <P>SOLUTION: This evaporation fuel separating equipment is provided with a high concentration separation unit 34 having a first separation membrane 36 for condensing the evaporation fuel gas, and a first chamber 38 and a second chamber 40 partitioned by the first separation membrane 36. The first separation membrane 36 is so disposed that liquid stuck to an arbitrary point reaches a lowermost part 70 by the operation of the gravity. The high concentration separation unit 34 is provided with a liquid sump discharge part 74 in a lower position than the lowermost part 70 so as to store or discharge the liquid reaching the lowermost part 70 without being contacted with the first separation membrane 36. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporative fuel separation apparatus, and more particularly to an evaporative fuel separation apparatus suitable for treating evaporative fuel generated in a fuel tank of an internal combustion engine without releasing it to the atmosphere.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 63-270524.
As disclosed in the publication, there is known a device for condensing evaporated fuel contained in gas using a separation membrane.
With such a device, it is possible to realize, for example, a system for condensing the evaporated fuel generated inside the fuel tank and recovering it as fuel.

[0003]

By the way, on the surface of the separation membrane for condensing the evaporated fuel, due to the difference between the temperature of the gas before or after the concentration and the temperature of the separation membrane or the like,
Condensation of fuel and moisture may occur. In order to keep the characteristics of the separation membrane stable, it is desirable that the droplets of fuel and water generated by dew condensation do not stay on the separation membrane for a long period of time.

In the above-mentioned conventional apparatus, the separation membrane is arranged in an inclined state. When the separation membrane is inclined in this way, the droplets generated by dew condensation flow down to the lowermost position of the separation membrane due to the action of gravity. Therefore, according to the above-mentioned conventional device, it is possible to avoid the situation where the main part of the separation membrane is exposed to the liquid droplets for a long period of time.

However, the above-mentioned conventional device is not provided with a mechanism for treating the droplets that have reached the lowermost position of the separation membrane. For this reason, the liquid droplets that have reached the lowermost position are then retained at that position, and as a result, the lowermost position of the separation membrane may be exposed to the liquid droplets of fuel and water for a long period of time.

The present invention has been made to solve the above problems, and a separation membrane for condensing evaporative fuel can be used for a long period of time as droplets of fuel, water, etc. at any part. An object is to provide an evaporated fuel separation device that is not exposed.

[0007]

The invention according to claim 1 is
An evaporative fuel separation device, comprising: an evaporative fuel separation unit having a separation membrane for condensing an evaporative fuel gas, and a first chamber and a second chamber divided by the separation membrane, wherein the separation membrane is The liquid attached to an arbitrary point on the separation membrane is arranged so as to reach a predetermined lowermost portion by the action of gravity, and the vaporized fuel separation unit removes the liquid reaching the lowermost portion from the above. It is characterized in that a liquid pool discharge part for storing or discharging without contacting the separation membrane is provided at a position lower than the lowermost part.

According to a second aspect of the invention, there is provided the fuel vapor separation apparatus according to the first aspect, wherein the separation membrane has a horizontal plane including two orthogonal tangent lines at all points on the separation membrane. It is characterized in that it is arranged so as not to become.

The invention according to claim 3 is the invention according to claim 1 or 2.
The evaporative fuel separation device according to claim 1, wherein the first chamber and the second chamber are provided such that one chamber is located above the other chamber, and the liquid pool discharge portion is the first chamber and the second chamber. One of the first chamber and the second chamber is characterized by including a first liquid pool discharge part that is electrically connected to a chamber located above.

A fourth aspect of the present invention is the evaporated fuel separation device according to any one of the first to third aspects, wherein:
The chamber and the second chamber are provided such that one chamber is located above the other chamber, and the first chamber and the second chamber are provided.
A process gas passage for discharging the condensed evaporated fuel gas is in communication with a lowermost position of the lower chamber among the chambers.

According to a fifth aspect of the present invention, there is provided the fuel vapor separation apparatus according to the fourth aspect, further comprising a fuel tank for storing liquid fuel to be fed to the internal combustion engine, wherein the fuel vapor separation unit comprises the fuel. It is arranged above the tank, and the processing gas passage communicates with the fuel tank.

According to a sixth aspect of the present invention, there is provided the evaporative fuel separation apparatus according to any one of the first to fifth aspects, wherein the evaporative fuel separation unit comprises a plurality of the evaporative fuel separation units and the first evaporative fuel separation unit is a first stage. The chamber or the second chamber is provided with a communication passage for connecting the first chamber or the second chamber of the evaporative fuel separation unit in the subsequent stage in series, and the two chambers communicated by the communication passage are positioned above and below each other. It is arranged in.

According to a seventh aspect of the present invention, there is provided the fuel vapor separation apparatus according to any one of the first to sixth aspects, wherein the vaporized fuel processing apparatus has a concentration reduced by being processed by the fuel vapor separation unit. A low-concentration gas passage that recirculates to the upstream of the evaporative fuel separation unit; and a pressure regulating valve that is arranged in the low-concentration gas passage and that generates a predetermined set pressure on the evaporative fuel separation unit side; And a return passage liquid pool discharge portion for discharging or storing the liquid that has reached the lowest portion of the gas passage below the pressure regulating valve.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that elements common to each drawing are denoted by the same reference numerals, and redundant description will be omitted.

Embodiment 1. 1 is a diagram for explaining the configuration of an evaporated fuel processing apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the apparatus of this embodiment includes a fuel tank 10. A low-pressure feed pump 12 (hereinafter, simply referred to as “feed pump 12”) is arranged inside the fuel tank 10. A suction pipe 14 for sucking the fuel in the fuel tank 10 communicates with the feed pump 12, and a fuel pipe 16 for feeding the fuel to an internal combustion engine (not shown) communicates with the suction pipe 14.

A canister 20 communicates with the fuel tank 10 through a vapor passage 18. Canister 20
Has activated carbon inside. The evaporated fuel generated inside the fuel tank 10 flows into the canister 20 through the vapor passage 18 and is adsorbed by the activated carbon.

Inside the canister 20, a heater 22 is arranged together with activated carbon. The heater 22 can appropriately heat the activated carbon. Canister 20
Also has an air vent 24. At the air port 24,
An overpressure prevention valve 26 for preventing excessive pressure from being generated inside the canister 20 is provided. The overpressure prevention valve 26 is a one-way valve that allows only the flow of fluid flowing out from the inside of the canister 20, and is open to the atmosphere via an air cleaner (not shown).

A purge passage 28 communicates with the canister 20. The purge passage 28 is provided with a negative pressure adjusting valve 30 and communicates with the suction port of the purge gas circulation pump 32 downstream of the adjusting valve 30. Negative pressure adjustment valve 30
Is a one-way valve that allows only the flow of fluid from the canister 20 toward the purge gas circulation pump 32, and is provided to generate a predetermined negative pressure near the suction port when the purge gas circulation pump 32 is operated. .

At the discharge port of the purge gas circulation pump 32,
The high concentration separation unit 34 is in communication. The high-concentration separation unit 34 includes a first separation membrane 36 and a first chamber 38 and a second chamber 40 that are separated by the first separation membrane 36. More specifically, the discharge port of the purge gas circulation pump 32 described above communicates with the first chamber 38. On the other hand, in the second chamber 40, the processing gas passage 4
2 are in communication. The process gas passage 42 is provided in the fuel tank 1.
The inside of 0 communicates with the suction pipe 14, that is, the suction port of the feed pump 12.

Above the high concentration separation unit 34, a medium concentration separation unit 44 is arranged. The medium-concentration separation unit 44 includes a second separation membrane 46, and a first chamber 48 and a second chamber 50 that are separated by the second separation membrane 46. Separation unit for medium concentration 4
The fourth chamber 48 of No. 4 communicates with the first chamber 38 of the separation unit 34 for high concentration via the communication passage 52.

A canister-introduced gas passage 54 communicates with the first chamber 48 of the intermediate concentration separation unit 44. The canister-entry gas passage 54 communicates with the above-described canister 20, and can recirculate the gas flowing out from the medium-concentration separation unit 44 to the canister 20. Further, the canister inlet gas passage 54 is provided with a pressure regulating valve 56 near the end on the medium concentration separation unit 44 side, and is provided with a negative pressure prevention valve 58 near the end on the canister 20 side.

The pressure regulating valve 56 is a medium concentration separation unit 44.
Is a one-way valve that allows only the flow of fluid from the canister 20 to the canister 20, and on the upstream side thereof, more specifically, in the path from the purge gas circulation pump 32 to the pressure regulating valve 56,
It is provided to generate a predetermined positive pressure. on the other hand,
The negative pressure prevention valve 58 is a one-way valve that communicates with the atmosphere via an air cleaner (not shown) and allows only the inflow of the atmosphere into the canister inlet gas passage 54. Negative pressure prevention valve 58
Are provided in order to prevent an unreasonably large negative pressure from being generated inside the canister inlet gas passage 54 or inside the canister 20.

A circulation gas passage 60 communicates with the second chamber 50 of the intermediate concentration separation unit 44. Circulating gas passage 6
0 communicates with the purge passage 28 downstream of the negative pressure adjusting valve 30. Therefore, according to the circulation gas passage 60, the second chamber 50 of the intermediate concentration separation unit 44 and the suction port of the purge gas circulation pump 32 can be brought into conduction.

As shown in FIG. 1, the apparatus of this embodiment is provided with an evaporation processing control computer 62 for controlling the heater 22 and the purge gas circulation pump 32 described above (hereinafter referred to as ECU: Electronic Control Unit). ). ECU
Specifically, 62 operates the purge gas circulation pump 32 when a predetermined purge condition is satisfied. In the present embodiment, the purging condition is set only when the fuel concentration of the gas discharged from the canister is a predetermined value or more (for example, 15% or more).
The establishment is determined. Therefore, the purge gas circulation pump 32 operates only when the fuel concentration of the gas discharged from the canister is 15% or more.

When the purge gas circulation pump 32 operates,
The negative pressure generated on the suction port side is guided to the canister 20,
The gas discharged from the canister flows out into the purge passage 28. Also,
The negative pressure generated by the purge gas circulation pump 32 is transmitted through the circulation gas passage 60 to the second chamber 5 of the intermediate concentration separation unit 44.
It is also led to 0. Therefore, the purge gas circulation pump 32
In the steady state, the high concentration separation unit 34 compresses the mixed gas of the canister exit gas supplied from the purge passage 28 and the circulation gas supplied from the circulation gas passage 60.
To the first chamber 38.

When the purge gas circulation pump 32 operates as described above, the discharge pressure of the pump acts on the system from the discharge port of the pump 32 to the pressure regulating valve 56. On the other hand, the internal pressure of the fuel tank is introduced into the second chamber 40 of the separation unit 34 for high concentration via the processing gas passage 42. Further, in the second chamber 50 of the separation unit 44 for medium concentration, as described above, the pump 3
The negative pressure generated by 2 is introduced. Therefore, in this case, on both sides of the first separation membrane 36 of the high concentration separation unit 34 and on both sides of the second separation membrane 46 of the middle concentration separation unit 44,
In both cases, a differential pressure is generated such that the first chamber 38, 48 side has a higher pressure than the second chamber 40, 50 side.

The first separation film 36 and the second separation film 46 are
It is a thin film composed of a polymeric material such as polyimide,
When exposed to gas containing air and fuel, it exhibits a property of separating the two due to the difference between the solubility of air and the solubility of fuel in the membrane. More specifically, the first separation membrane 36 and the second separation membrane 46 have a differential pressure on both sides of the membrane such that the gas containing the evaporated fuel is introduced to one surface and the pressure on that side becomes high. When given, it has the property of passing condensed gas with a higher concentration of evaporated fuel to the low pressure side of the membrane.

Therefore, with the operation of the pump 32, the mixed gas flows into the first chamber 38 of the separation unit 34 for high concentration, and the pressure of the first chamber 38 becomes high on both sides of the first separation membrane 36. When such a differential pressure is generated, the evaporated fuel in the mixed gas is condensed on the second chamber 40 side. As a result, the mixed gas in the first chamber 38 has a lower fuel concentration than that at the time of inflow (hereinafter,
It is referred to as “medium concentration gas”), and a high concentration processing gas is generated in the second chamber 40.

The medium concentration gas flowing out of the first chamber 38 of the high concentration separation unit 34 flows into the first chamber 48 of the medium concentration separation unit 44. The medium concentration separation unit 44 is
When the medium concentration gas flows into the first chamber 48, the second separation membrane 46
Thus, the evaporated fuel in the medium-concentration gas is condensed to generate a circulating gas having a higher concentration than the medium-concentration gas in the second chamber 50. The generated circulating gas is supplied to the suction port of the purge gas circulation pump 32 through the circulating gas passage 60.

The apparatus of the present embodiment is provided so that the concentration of the circulating gas is about 65% in a steady state when the concentration of the canister gas is 15%. in this case,
The concentration of the mixed gas is about 60%. Then, when the mixed gas of about 60% is supplied, the separation unit 34 for high concentration converts the mixed gas to 95% or more of the processing gas and 40% of the mixed gas.
It is designed so that it can be separated into medium concentration gas of about%. Further, when the medium concentration gas of about 40% is supplied, the medium concentration separation unit 44 reduces the medium concentration gas to 6%.
It is designed so that it can be separated into about 5% of circulating gas and less than 5% of gas entering the canister. Therefore, according to the apparatus of this embodiment, 95% or more of the processing gas and less than 5% of the gas entering the canister can be generated in the steady state.

The feed pump 12 supplies 300 kPa of fuel.
It has the ability to overpress to a certain degree. Feed pump 12
The process gas sucked into the gas becomes a liquid fuel when pressurized with such a pressure. At this time, if the processing gas contains a large amount of air, there arises inconveniences such as vapor lock of the feed pump 12 and generation of abnormal noise. On the other hand, if the amount of air contained in the processing gas is small, the problems will not occur because the air dissolves in the fuel as the processing gas is pressurized.

The ratio of air that does not generate vapor lock or abnormal noise is determined according to the capacity of the feed pump 12, that is, the fuel flow rate and fuel pressure generated by the feed pump 12. Generally, in a feed pump mounted on a vehicle, if the air concentration in the processing gas is less than 5%, that is, if the fuel concentration of the processing gas is 95% or more, vapor lock and noise may occur. There is no. Therefore, according to the system of the present embodiment, in combination with the general feed pump 12 mounted on the vehicle, the processing gas is returned to the fuel tank 10 without causing the problem of vapor lock or abnormal noise. be able to.

In the apparatus of this embodiment, the gas entering the canister is reused as a gas for purging the evaporated fuel adsorbed on the canister 20. The vaporized fuel adsorbed in the canister 20 is purged by passing a gas having a sufficiently low concentration inside the canister 20. In the device of the present embodiment, as described above, the fuel concentration of the gas entering the canister is suppressed to 5% or less. Further, the apparatus of the present embodiment is configured so that the heater 22
Therefore, the canister 20 is heated. The evaporated fuel adsorbed on the canister 20 is
When the temperature of 0 rises, it becomes a state of easy desorption. Therefore, according to the apparatus of the present embodiment, the evaporated fuel can be efficiently purged by the gas entering the canister.

Next, with reference to FIG. 2, the characteristic portion of the fuel vapor processing apparatus of this embodiment will be described. 2 is shown in FIG.
It is the figure which expanded and represented the circumference | surroundings of the separation unit 34 for high concentrations shown in FIG. As shown in FIG. 2, the first chamber 38 and the second chamber 40 of the separation unit 34 for high concentration are positioned above the second chamber 40 by the first separation membrane 36 that is obliquely arranged. Is divided into

When the first separation membrane 36 is inclined as described above, the lowermost position 70 is formed at the end portion (the lower left end portion in FIG. 2) of the first separation membrane 36. The high concentration separation unit 34 includes a spacer 72 for forming a predetermined space between the lowermost position 70 of the first separation membrane 36 and the wall surface of the unit 34. The spacer 72 is
It is provided so as to extend further below the lowermost position 70.

On the surface of the first separation membrane 36 on the first chamber 38 side,
Droplets may adhere due to condensation of evaporated fuel or water. According to the above-described configuration, the droplets attached to the first separation film 36 flow down to the lowermost position 70 of the first separation film 36 due to the action of gravity regardless of the attachment position. Then, the droplet passes through the lowermost position 70 and reaches the region of the spacer 72.

The high-concentration separation unit 34 is provided with a liquid pool discharge portion 74 for discharging the droplets thus reaching the spacer 72 from the first chamber 38. The liquid pool discharge part 74 has an opening at a position lower than the lowermost position 70, a liquid pool 76 for storing the liquid flowing out from the opening part, and a gravity provided downstream of the liquid pool 76. A valve 78 is provided. The gravity valve 78 is a valve mechanism that opens when the weight of the liquid in the liquid reservoir 76 reaches a predetermined weight, and is in communication with the fuel tank 10 (see FIG. 1).

According to the above-mentioned structure, the droplets of fuel, water, etc. attached to the surface of the first separation membrane 36 on the first chamber 38 side due to dew condensation or the like are located at the lowermost position of the membrane 36 by the action of gravity. 7
It is led to 0, and then to the liquid pool 76 again quickly. Therefore, according to the apparatus of this embodiment, it is possible to effectively prevent the surface of the first separation membrane 36 on the first chamber 38 side including the vicinity of the lowermost position 70 from coming into contact with the liquid droplets for a long period of time. can do.

By the way, in the above-mentioned configuration, the first
The spacer 72 is used in order to prevent the liquid reaching the vicinity of the lowermost position 70 of the separation membrane 36 from staying in the lowermost position 70 for a long period of time, but the present invention is not limited to this. Absent. That is, the liquid that has flown to the lowermost position 70 does not stay and quickly accumulates in the liquid pool 76.
The spacer 72 may be omitted if the structure is such that it flows toward.

As shown in FIG. 2, the second chamber 40 of the separation unit 34 for high concentration has a bottom surface 82 formed in a tapered shape so that the central portion thereof is at the lowermost position 80.
The processing gas passage 42 is connected to the lowermost position 80 of the bottom surface 82 thereof.

In the second chamber 40 of the separation unit 34 for high concentration, the evaporated fuel in the processing gas may be naturally liquefied.
According to the above structure, the liquid fuel generated by natural liquefaction is collected at the lowermost position 80 of the bottom surface 82 by the action of gravity, and flows out to the processing gas passage 42 from there. In the present embodiment, the fuel tank 10 is arranged below the high concentration separation unit 34 (see FIG. 1). For this reason,
The liquid fuel flowing out to the processing gas passage 42 efficiently flows into the fuel tank 10 due to the action of gravity.

On the surface of the first separation membrane 36 on the second chamber 40 side,
As in the case of the surface on the first chamber 38 side, droplets may adhere due to the condensation of evaporated fuel and moisture. In this embodiment,
Since the first separation membrane 38 is arranged in an inclined state,
The droplets attached to the surface on the second chamber 40 side drop on the bottom surface 82 by the action of gravity or flow down to the lowermost position 70 of the first separation membrane 36. Then, those droplets flow out from the lowermost position 80, and are collected in the fuel tank 10 through the processing gas passage 42, similarly to the fuel that is naturally liquefied in the second chamber 40.

As described above, according to the high-concentration separation unit 34 of the present embodiment, the surface of the first separation membrane 36 on the second chamber 40 side including the vicinity of the lowermost position 70 has fuel, water, etc. It is possible to effectively prevent long-term contact with the liquid droplets. That is, according to the high-concentration separation unit 34 of the present embodiment, when a droplet adheres to any surface of the first separation film 36 due to dew condensation or the like, the droplet remains in the first state for a long period of time. It is possible to effectively prevent staying in contact with the first separation membrane 36. Therefore, according to the device of the present embodiment, it is possible to effectively prevent the characteristics of the first separation film 36 from changing due to the influence of those droplets.

By the way, in the above-mentioned configuration, the first
The structure in which the spacer 72 is provided near the lowermost position 70 of the separation membrane 36 and the structure in which the bottom surface 82 of the second chamber 40 is tapered (the structure in which the bottom surface 82 is inclined) are used in combination. Do not always have to be used in combination. That is, when the spacer 72 is present, the bottom surface 8
Even if 2 is not inclined, the droplets staying on the bottom surface 82 do not come into contact with the first separation membrane 36. Therefore, when the spacer 72 is present, the inclination of the bottom surface 82 may be omitted. On the contrary, when the bottom surface 82 is inclined, the droplets generated in the second chamber 40 do not stay at the position in contact with the first separation membrane 36 for a long time even if the spacer 72 does not exist. . Therefore, considering only the circumstances on the side of the second chamber 40,
If the bottom surface 82 is inclined, the spacer 72
May be omitted.

In the apparatus of this embodiment, the first chamber 48 and the second chamber 50 of the separation unit for medium concentration 44 have the second chamber 50 with the first chamber 48 being the diagonally arranged second separation membrane 46. It is divided so that it is located below.

When the second separation film 46 is inclined as described above, the lowermost position 84 thereof is at the end portion of the second separation film 46 (see FIG. 2).
In the lower left part). The medium-concentration separation unit 44 includes a spacer 86 for forming a predetermined space between the lowermost position 84 of the second separation membrane 46 and the wall surface of the unit 44. The spacer 86 is provided so as to extend further below the lowermost position 84.

On the surface of the second separation membrane 46 on the second chamber 50 side,
Droplets may adhere due to condensation of evaporated fuel or water. According to the configuration described above, the droplets attached to the second separation film 46 flow down to the lowermost position 84 of the second separation film 46 due to the action of gravity regardless of the attachment position. Then, the droplet passes through the lowermost position 84 and reaches the region of the spacer 86.

The circulation gas passage 60 communicates with the second chamber 50 at a position lower than the lowermost position 84 so that the liquid droplets thus reaching the spacer 86 are promptly discharged from the second chamber 50. ing. Therefore, droplets of fuel, water, and the like attached to the surface of the second separation membrane 46 on the side of the second chamber 50 due to dew condensation are guided to the lowermost position 84 of the membrane 46 by the action of gravity, and then further. It is quickly guided to the inside of the circulating gas passage 60. Therefore, according to the apparatus of the present embodiment, the second separation membrane 46 including the vicinity of the lowermost position 84 is included.
It is possible to effectively prevent the surface on the side of the second chamber 50 from contacting the liquid droplets for a long period of time.

By the way, in the above configuration, the second
The spacer 86 is used in order to prevent the liquid reaching the lowermost position 84 of the separation membrane 46 from staying in the lowermost position 84 for a long period of time, but the present invention is not limited to this. Absent. That is, the spacer 86 may be omitted when the structure is such that the liquid flowing to the lowermost position 84 quickly flows out to the circulating gas passage 60 without staying.

As shown in FIG. 2, the first chamber 48 of the medium-concentration separation unit 44 is provided with a bottom surface 90 formed in a tapered shape so that the central portion thereof is at the lowermost position 88.
The communication passage 52 has a lowermost position 88 on the bottom surface 90.
It is connected to the.

In the first chamber 50 of the separation unit for medium concentration 44, the evaporated fuel in the gas may spontaneously liquefy. Also, droplets of evaporated fuel or water may adhere to the surface of the second separation membrane 46 on the first chamber 48 side due to dew condensation. According to the above-mentioned structure, the naturally liquefied fuel and the liquid droplets generated by the condensation are dropped on the bottom surface 90 by the action of gravity, or the bottom surface 90 is transmitted along the lowermost position 84 of the second separation membrane 46.
Runs down. Then, these liquids flow out from the lowermost position 88 of the bottom surface 90, flow into the first chamber 38 of the high concentration separation unit 34 via the communication passage 52.

In the present embodiment, the first chamber 3 of the high-concentration separation unit 34 connected in series via the communication passage 52.
8 and the first chamber 48 of the separation unit for medium concentration 44 are arranged so that the former 38 is located below the latter 48. Therefore, the liquid fuel that has flowed out into the communication passage 52 efficiently flows into the first chamber 38 of the high-concentration separation unit 34 due to the action of gravity.

As described above, according to the medium-concentration separation unit 44 of the present embodiment, the surface of the second separation membrane 46 including the vicinity of the lowermost position 84 and the droplets of fuel, water, or the like remain for a long time. It is possible to effectively prevent contact across. Therefore, according to the device of the present embodiment, it is possible to effectively prevent the characteristics of the second separation film 46 from changing due to the influence of the droplets.

By the way, in the above configuration, the second
A configuration in which the spacer 86 is provided near the lowermost position 84 of the separation membrane 46 and a configuration in which the bottom surface 90 of the first chamber 48 is tapered (configuration in which the bottom surface 90 is inclined) are used in combination. Do not always have to be used in combination. That is, when the spacer 86 is present, the bottom surface 9
Even if 0 is not inclined, the droplets staying on the bottom surface 90 do not come into contact with the second separation film 46. Therefore, when the spacer 86 is present, the inclination of the bottom surface 90 may be omitted. On the other hand, when the bottom surface 90 is inclined, the droplets generated in the first chamber 48 do not stay at the position in contact with the second separation membrane 46 for a long period of time even if the spacer 86 does not exist. . Therefore, considering only the circumstances on the side of the first chamber 48,
If the bottom surface 90 has a slope, the spacer 86
May be omitted.

In the apparatus of this embodiment, dew condensation of fuel or water may occur even in the flow passage below the pressure regulating valve 56 of the canister inlet gas passage 54. The apparatus of the present embodiment includes a liquid pool discharge section 94 for collecting those liquids. The liquid pool discharge part 94 is provided in the canister-inlet gas passage 5
The fluid reservoir 96 is provided at the lowest position in the flow path below the pressure regulating valve 56 of No. 4 and opened. In the present embodiment, since the lowest position in the flow passage below the pressure regulating valve 56 is the housing portion of the pressure regulating valve 56, the liquid pool 96 is provided in the housing portion of the pressure regulating valve 56 as shown in FIG. It is open.

The liquid pool discharge section 94 is further provided with a liquid pool 9
A gravity valve 98 is provided downstream of 6. The gravity valve 98 is a valve mechanism that opens when the weight of the liquid in the liquid pool 96 reaches a predetermined weight and communicates with the fuel tank 10 (see FIG. 1).

According to the above-mentioned structure, the liquid droplets generated in the flow path below the pressure regulating valve 56 due to the dew condensation are guided to the liquid pool 96 by the action of gravity, and then the gravity valve 98 opens to open the fuel. It is collected in the tank 10. For this reason,
According to the apparatus of the present embodiment, it is possible to efficiently collect the droplets generated in the canister entrance gas passage.

As described above, according to the apparatus of this embodiment, the first separation membrane 36 or the second separation membrane 46 is provided inside the high concentration separation unit 34 or the medium concentration separation unit 44.
However, it is possible to effectively prevent the liquid from being exposed to the liquid for a long period of time. Further, the liquid droplets of the fuel generated inside them or inside the canister inlet gas passage 54 can be directly and efficiently collected in the fuel tank 10. Therefore, according to the apparatus of the present embodiment, it is possible to realize efficient fuel recovery while achieving excellent durability.

In the first embodiment described above, the separation unit for high concentration 34, the separation unit for medium concentration 44,
And the liquid pool discharge parts 74 and 94 are the same as the above-mentioned claim 1.
It corresponds to the “evaporated fuel separation device” described, and each of the first separation membrane 36 and the second separation membrane 46 corresponds to the “separation membrane” described in claim 1, and the liquid pool discharge part 74.
Each of the circulation gas passage 60 and the circulation gas passage 60 corresponds to the "liquid pool discharge portion".

Further, in the above-described first embodiment,
The first chamber 38 of the high-concentration separation unit 34 and the second chamber 50 of the medium-concentration separation unit 44 are included in the “upper chamber” described in claim 3 of the liquid pool discharge part 74 and the circulating gas passage 60. Each of the “first” described in claim 3
Of the liquid pool.

Further, in the above described first embodiment,
The second chamber 40 of the high-concentration separation unit 34 and the first chamber 48 of the medium-concentration separation unit 44 are included in the “chamber located below” in claim 4, and the processing gas passage 42 and the communication passage 52 are respectively provided. This corresponds to the "process gas passage" in claim 4.

Further, in the above described first embodiment,
The first chamber 38 of the high-concentration separation unit 34 and the first chamber 48 of the medium-concentration separation unit 44 correspond to "two chambers connected by a communication passage" in claim 6.

Further, in the above-described first embodiment,
The canister inlet gas passage 54 corresponds to the "low-concentration gas passage" in claim 7, and the liquid pool discharge portion 9
Reference numeral 4 corresponds to the "reflux passage liquid pool discharge portion".

Embodiment 2. Next, a second embodiment of the present invention will be described with reference to FIG. The apparatus according to the present embodiment has the same configuration as the apparatus according to the first embodiment, except that the separation unit for high concentration 34 and the separation unit for medium concentration 44 have different structures from the case of the first embodiment. ing.

FIG. 3 is a view for explaining the structure of the high concentration separation unit 100 used in this embodiment. More specifically, FIG. 3A is a plan view showing a cross section of the separation unit 100 for high concentration. Further, FIG. 3 (B) shows the separation unit 100 for high concentration as shown in FIG. 3 (A).
FIG. 7 is a cross-sectional view obtained by cutting along the line BB shown in FIG.

In FIG. 3, the separation unit 10 for high concentration is used.
Liquid pool discharge part 74 and process gas passage 42 connected to 0
There is no difference in the configuration from the first embodiment. Therefore, regarding them, the first embodiment
The same reference numerals as in the above case are given and the description thereof is omitted. The medium concentration separation unit used in this embodiment has substantially the same configuration as the high concentration separation unit 100 shown in FIG. Therefore, in the following description, only the high concentration separation unit 100 will be described, and the middle concentration separation unit will be omitted.

As shown in FIG. 3A, the high concentration separation unit 100 used in this embodiment has a first separation membrane 102 wound in a spiral shape. The first separation membrane 102 is folded back near the center of the high-concentration separation unit 100 to have a bag shape that separates the internal space from the external space. 3A and 3B, the pear-skinned region is the first bag-shaped region.
It is the internal space of the separation membrane 102. In addition, the regions outlined in these figures are the outer space of the bag-shaped first separation membrane 102. Hereinafter, the satin-finished internal space will be referred to as the "first chamber 104", while the outlined external space will be referred to as the "second chamber 106".

As shown in FIG. 3B, the first chamber 104
Communicates with the discharge port of the purge gas circulation pump 32 at the bottom thereof, and the communication passage 52 at the top thereof.
Is in communication with. The second chamber 106 communicates with the processing gas passage 42 at the bottom thereof. According to this structure, the high-pressure mixed gas is introduced into the first chamber 104,
A differential pressure can be generated on both sides of the separation membrane 102.
Then, the high-concentration processing gas is caused to flow from the second chamber 106 to the processing gas passage 42, and the communication passage 5 is discharged from the first chamber 104.
The medium-concentration gas can be made to flow out to No. 2. That is, according to the high-concentration separation unit 100 of this embodiment, it is possible to realize the same function as in the first embodiment.

In this embodiment, the first separation membrane 102
Is spirally wound, it is possible to store the first separation membrane 102 having a sufficient area inside while suppressing the volume of the high concentration separation unit 100 to be sufficiently small. Therefore, according to the device of the present embodiment, it is possible to achieve the same ability as that of the device of the first embodiment with a smaller physique.

In this embodiment, the first separation membrane 102
Is configured such that the axis of the spirally wound film is oriented in the vertical direction. In other words, the first separation membrane 102
Is configured such that, at all points on the surface, two tangent lines that are orthogonal to each other are hypothesized, and when a plane including these two tangent lines is hypothesized, the virtual plane becomes a vertical plane. There is.

The constitution of the first separation membrane 102 is not limited to the above constitution, and it is sufficient that the axis of the spirally wound membrane is not oriented in the horizontal direction. That is, the virtual plane described above may be inclined with respect to the horizontal plane at all points on the first separation membrane 102. When the first separation membrane 102 has the structure of the present embodiment, or when the requirements of the modified example described above are satisfied, the liquid attached to the first separation membrane 102 is affected by gravity regardless of the attachment position. , Reaches the end of the first separation membrane 102 (the end on the lower side).

In the present embodiment, the lower end of the first separation membrane 102, that is, the lowermost position 108 of the first separation membrane 102 is, as shown in FIG. 3B, the high concentration separation unit 100. Is located at a predetermined distance from the bottom surface of the.
Then, between the bottom surface of the separation unit 100 for high concentration and the lowermost position 108, the first chamber 1
04 to separate the second chamber 106 from each other, the spacer 11
0 is placed.

According to the above configuration, the first separation film 102
Liquids such as fuel and water attached to the surface of the water flow down to the lowermost position 108 by the action of gravity, and then
It reaches the bottom of the high concentration separation unit 100 through the spacer 110. Therefore, according to the separation unit 100 for high concentration, it is possible to effectively prevent the first separation membrane 102 from being exposed to the liquid generated by dew condensation or the like for a long period of time.

As shown in FIG. 3B, a liquid pool discharge portion 74 is opened on the bottom surface of the separation unit 100 for high concentration so as to be electrically connected to the first chamber 104, and the second chamber 1
The processing gas passage 42 is opened so as to be electrically connected to 06. Therefore, both the liquid reaching the bottom surface inside the first chamber 104 and the liquid reaching the bottom surface inside the second chamber 106 are the same as in the first embodiment.
Recovered to 0. Therefore, the separation unit 100 for high concentration
According to this, the liquid generated due to dew condensation or the like can be efficiently collected in the fuel tank 10.

As described above, the high-concentration separation unit 100 used in this embodiment realizes the same function as that of the high-concentration separation unit 34 in the first embodiment while realizing a reduction in size. You can Also,
The medium-concentration separation unit used in the present embodiment can also realize the same function as the medium-concentration separation unit 44 in the first embodiment while realizing a reduction in size. Therefore, according to the device of the present embodiment, the same effect as that of the device of the first embodiment can be realized with a smaller physique.

[0076]

Since the present invention is constructed as described above, it has the following effects. Claim 1
Alternatively, according to the invention described in 2, the liquid attached on the separation membrane can reach the lowermost portion. Further, since the liquid pool discharge part is provided at a position lower than the lowermost part,
It is possible to reliably prevent the liquid reaching the lowermost portion from coming into contact with the separation membrane for a long period of time.

According to the third aspect of the invention, the liquid generated in the upper chamber of the first chamber and the second chamber is
It can be properly guided to the first liquid pool discharge part. Therefore, according to the present invention, it is possible to reliably prevent the separation membrane from coming into contact with the liquid for a long period of time in the chamber located above.

According to the fourth aspect of the invention, the condensed evaporated fuel gas is generated in the lower chamber of the first chamber and the second chamber. Further, in the present invention, the processing gas passage communicates with the lowermost position in the lower chamber. Therefore, according to the present invention, the liquid generated in the chamber located below can be discharged from the process gas passage together with the condensed evaporated fuel gas.

According to the invention described in claim 5, since the evaporated fuel separation unit is arranged above the fuel tank,
The liquid generated in the evaporated fuel separation unit and the condensed evaporated fuel gas can be efficiently guided to the fuel tank by the action of gravity.

According to the sixth aspect of the invention, since the plurality of chambers connected in series via the communication passage are located above and below each other, the liquid generated in one chamber is efficiently transferred by the action of gravity. Can be guided to the other chamber.

According to the seventh aspect of the present invention, the low-concentration gas passage can recirculate the concentration of the evaporated fuel processing device upstream of the evaporated fuel separation unit. Then, the liquid generated in the flow passage of the low-concentration gas passage below the pressure regulating valve can be guided to the pipe flow passage liquid pool discharge part.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the configuration of an evaporated fuel processing device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a main part of the device according to the first embodiment.

FIG. 3 is a diagram for explaining the configuration of a high-concentration separation unit used in the device according to the second embodiment.

[Explanation of symbols]

10 Fuel tank 12 Low pressure feed pump 20 canisters 22 heater 28 Purge passage 30 Negative pressure adjustment valve 32 Purge gas circulation pump 34; 100 Separation unit for high concentration 36; 102 First separation membrane 38,48; 104 Room 1 40, 50; 106 second room 42 Process gas passage 44 Separation unit for medium concentration 46 Second separation membrane 52 communication passage 54 Canister gas passage 60 Circulating gas passage 62 ECU (Electronic Control Unit) 70, 84; 108 lowest position 72,86; 110 spacer 74,94 Liquid pool discharge part 76,96 liquid pool 78,98 Gravity valve

Claims (7)

[Claims] 1. An evaporative fuel separation unit having a separation membrane for condensing evaporated fuel gas, and a first chamber and a second chamber divided by the separation membrane, wherein the separation membrane is on the separation membrane. The liquid attached to an arbitrary point of is arranged so as to reach a predetermined lowermost portion by the action of gravity, and the vaporized fuel separation unit causes the liquid reaching the lowermost portion to the separation membrane. An evaporative fuel separation device, comprising a liquid pool discharge part for storing or discharging without contacting the liquid pool at a position lower than the lowermost part. 2. The separation membrane is arranged such that, at all points on the separation membrane, a plane including two orthogonal tangent lines is not a horizontal plane.
The evaporative fuel separation device described. 3. The first chamber and the second chamber are provided such that one chamber is located above the other chamber, and the liquid pool discharge portion is provided in the first chamber and the first chamber. The evaporative fuel separation device according to claim 1 or 2, further comprising a first liquid pool discharge part that is electrically connected to the upper chamber of the two chambers. 4. The first chamber and the second chamber are provided such that one chamber is located above the other chamber, and one of the first chamber and the second chamber is located below the other chamber. The evaporative fuel separation apparatus according to any one of claims 1 to 3, wherein a process gas passage for discharging the condensed evaporative fuel gas is in communication with a lowermost position of the located chamber. 5. A fuel tank for storing liquid fuel to be fed to an internal combustion engine is provided, the vaporized fuel separation unit is disposed above the fuel tank, and the process gas passage communicates with the fuel tank. The evaporative fuel separation device according to claim 4, wherein: 6. A plurality of the vaporized fuel separation units are provided, and a first chamber or a second chamber of the vaporized fuel separation unit in the preceding stage,
A communication passage that serially communicates with the first chamber or the second chamber of the evaporative fuel separation unit in the subsequent stage is provided, and the two chambers communicated by the communication passage are arranged so as to be located above and below each other. The evaporative fuel separation device according to any one of claims 1 to 5. 7. A low-concentration gas passage that circulates an evaporated fuel processing device, the concentration of which has been reduced by the treatment in the evaporated fuel separation unit, to the upstream of the evaporated fuel separation unit, and a low-concentration gas passage. A pressure regulating valve for generating a predetermined set pressure on the side of the evaporative fuel separation unit, and a liquid which reaches or reaches a portion of the low-concentration gas passage that is located at the lowest position in the flow passage below the pressure regulating valve. 7. The evaporated fuel separation device according to any one of claims 1 to 6, further comprising a return passage liquid pool discharge portion for performing the operation.