JP2008045472A - Evaporated fuel treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaporated fuel treatment device provided with a sufficient separating performance in separation of water, dust and the like from air introduced from a vehicle outside, and securing sufficient purge air quantity for an intake system. <P>SOLUTION: A separator includes a cylinder chamber 61 having an blocked upper part and a blocked bottom part, a flow in port 64 through which air flows in, and a flow out port 65. The flow out port 65 is provided at a position above a side part of the cylinder chamber 61 and higher than the flow in port 64, and makes air flow out to a canister. A cylindrical body provided roughly concentrically with the cylinder chamber 61 and a plurality of fins toward a side part inner wall of the cylinder chamber 61 from a side part of the cylindrical body are provided in the cylinder chamber 61. The plurality of fans are formed in a spiral shape as a whole. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an evaporative fuel processing technique particularly in a vehicle including an internal combustion engine.

Conventionally, in an evaporative fuel processing apparatus in a vehicle equipped with an internal combustion engine, at the time of purging, the evaporative fuel generated in the fuel tank is guided to the canister and temporarily adsorbed, and the evaporative fuel adsorbed by the canister is introduced into the fresh air Combustion processing is performed by causing the air to be introduced into the intake system of the internal combustion engine through the purge control valve together with air introduced from the mouth.
In such an evaporative fuel processing apparatus, a separator that separates water, dust, and the like is provided near the fresh air inlet so that water, dust, and the like together with air do not enter from the fresh air inlet. For example, Patent Document 1 discloses a separator provided with a dust filter or the like at the bottom of a cylindrical container.

No. 7-693, Fig. 1

  By the way, although the separator of the conventional evaporative fuel processing apparatus disclosed by patent document 1 is excellent in isolation | separation performance using the filter system, the pressure loss of the air before and behind a separator is high, and is sufficient with respect to an intake system. In some cases, a sufficient amount of purge air could not be secured.

  In view of the above, the object of the present invention is to provide a sufficient amount of purge air for the intake system while providing sufficient separation performance when separating water, dust, and the like from air introduced from the outside of the vehicle. Another object of the present invention is to provide an evaporative fuel processing apparatus.

In order to achieve the above object, the present invention is an evaporative fuel processing apparatus for a vehicle equipped with an internal combustion engine, comprising a canister, a first passage, a second passage, a third passage, and a separator.
The canister adsorbs the evaporated fuel generated in the fuel tank. The first passage connects the fuel tank and the canister. The second passage connects the canister and the intake passage of the internal combustion engine. The third passage connects the outside of the vehicle and the canister. The separator is provided in the third passage and separates moisture and / or dust contained in the air introduced from the outside of the vehicle.
The separator has a cylinder chamber, a first inlet, a first outlet, a cylindrical body, and a plurality of fins. The cylinder chamber is closed at the top and bottom. Air flows into the first inlet, and the first outlet is disposed on the side of the cylinder chamber and at a higher position than the first inlet, and flows out into the canister. The cylindrical body is provided substantially concentrically with the cylinder chamber from the upper part of the cylinder chamber to at least the first outlet in the central axis direction of the cylinder chamber. The plurality of fins are provided from the side of the cylindrical body toward the inner wall of the side of the cylinder chamber, and are formed in a spiral shape as a whole.

  In this fuel vapor processing apparatus, air is introduced into the third passage from the outside of the vehicle. Before the air is sent to the canister, moisture and / or dust is separated by the separator. In the separator, the air outside the vehicle introduced from the first inlet passes through the donut-shaped region formed by the side of the cylindrical body and the inner wall of the side of the cylinder chamber from the first inlet. However, since the plurality of fins are provided spirally with respect to the cylindrical body, the air flow rises spirally inside the cylinder chamber. Become. Therefore, since the residence time of air in the cylinder chamber can be made as long as possible, high separation performance is ensured.

  According to the fuel vapor processing apparatus of the present invention, sufficient separation performance is provided when water, dust and the like are separated from air introduced from the outside of the vehicle. At the same time, since the filter system is not used as the separator, the pressure loss before and after the separator is small, and a sufficient purge air amount can be secured for the intake system.

  Hereinafter, preferred embodiments of the fuel vapor processing apparatus of the present invention will be described.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a fuel vapor processing apparatus according to an embodiment of the present invention. The evaporative fuel processing apparatus 1 is mounted on a vehicle equipped with an internal combustion engine. As shown in the figure, the evaporative fuel processing apparatus 1 includes a canister 3, an evaporative fuel passage 10 (first passage), a purge passage 11 (second passage), and air passages 12 and 13 (third passage). The separator 6, the purge control valve 30, the on-off valve 31, and the pressure sensor 40 are configured. The evaporated fuel passage 10 connects the canister 3 and the fuel tank 2. The purge passage 11 connects the canister 3 and the intake pipe 5 on the downstream side of the throttle valve 51.

  One end of the air passage 13 is opened to the atmosphere outside the vehicle, and the other end is connected to the opening 64 a via an inflow port 64 (described later) of the separator 6. One end of the air passage 12 is connected to the opening 65 a via an outflow port 65 (described later) of the separator 6, and the other end is connected to the vent 3 a of the canister 3. With this configuration, the canister 3 can communicate with the atmosphere outside the vehicle via the separator 6 and the air passages 12 and 13.

  The on-off valve 31 is an on-off valve that is a normally closed electromagnetic valve and is also referred to as a drain cut valve. The on-off valve 31 is provided on the air passage 12 in this embodiment. The on-off valve 31 is operated by the leak diagnosis control signal L_CTL of the control unit 4 to communicate or block the air passage 12. That is, the on-off valve 31 is opened when the leak diagnosis control signal L_CTL indicates “leak diagnosis stop”, and thereby the air passage 12 communicates. The on / off valve 31 is closed when the leak diagnosis control signal L_CTL indicates “execution of leak diagnosis”, and thereby the air passage 12 is blocked.

  The canister 3 contains an adsorbent 35 such as activated carbon. The evaporated fuel generated in the fuel tank 2 is guided by the evaporated fuel passage 10 and temporarily adsorbed. Further, as described above, the vent 3a of the canister 3 communicates with or blocks the atmosphere outside the vehicle in accordance with the operation of the on-off valve 31.

  The purge control valve 30 is an on-off valve constituted by a normally closed electromagnetic valve, and is provided in the purge passage 11. The purge control valve 30 is operated by the purge control signal P_CTL of the control unit 4. That is, the purge control valve 30 is open when the purge control signal P_CTL indicates “purge execution”, and remains closed when the purge control signal P_CTL indicates “purge stop”.

The control unit (C / U) 4 incorporating the microcomputer includes a pressure sensor 40 for detecting the pressure P in the apparatus (more specifically, the fuel tank 2 to the purge control valve 30), and other not shown. A detection signal from a sensor (for example, a fuel temperature sensor) is input. The detection signal from the pressure sensor 40 is used for leak diagnosis in the apparatus.
The control unit 4 performs various controls on the engine, determines whether to execute or stop the purge process according to the operating condition of the engine, controls the purge control valve 30 and the on-off valve 31 by the purge control signal P_CTL, and sends it to the canister 3. The adsorbed evaporated fuel is processed.

  Next, the structure of the separator 6 will be described with reference to FIGS. FIG. 2 shows (a) a top view and (b) a side view of the separator 6. FIG. 3 shows a cross-sectional view in FIG. 2B, that is, (a) a cross-sectional view taken along line AA and (b) a cross-sectional view taken along line BB. In FIG. 2, the upper, bottom, and side portions constituting the cylinder chamber 61 are assumed to be transparent so that the internal structure of the separator 6 becomes clear.

  As shown in FIG. 2, the separator 6 has a cylindrical shape as a whole. The separator 6 has, in appearance, a cylinder chamber 61 having a separation function for separating moisture and / or dust contained in the introduced air, and an inflow port 64 and an outflow port 65 provided in the cylinder chamber 61. The inflow port 64 is connected to the air passage 13 and the outflow port 65 is connected to the air passage 12 (see FIG. 1).

  As shown in FIG. 3A, the inflow port 64 is provided so that its central axis is substantially parallel to and close to the tangent to the side portion 61 a of the cylinder chamber 61. An opening 64 a (first inflow port) is formed at the joining position of the inflow port 64 and the cylinder chamber 61. Thereby, the air introduced from the opening 64 a flows along the side portion 61 a of the cylinder chamber 61.

  As shown in FIG. 3B, the outflow port 65 is provided such that its central axis is substantially parallel to and close to the tangent to the side portion 61 a of the cylinder chamber 61. An opening 65 a (second outlet) is formed at the joining position of the outflow port 65 and the cylinder chamber 61. Thereby, the air flowing along the side portion 61a of the cylinder chamber 61 is efficiently derived.

As shown in FIG. 2B, the outflow port 65 is provided at a higher position than the inflow port 64 in order to generate an air flow in the cylinder chamber 61 from below to above.
In the separator 6 shown in FIG. 2, the inflow port 64 and the outflow port 65 are substantially parallel in the top view, but the central axis of each port is substantially parallel to the tangent of the side portion 61 a of the cylinder chamber 61. As long as they are provided close to each other, they do not have to be parallel.

  In the cylinder chamber 61, the columnar body 62 extends downward from the upper portion 61 b of the cylinder chamber 61 to at least the position of the inflow port 64. The cylindrical body 62 is substantially concentric with the cylinder chamber 61. The lower end of the cylindrical body 62 is closed, and the air in the cylinder chamber 61 does not enter the cylindrical body 62.

A fin group 63 (a plurality of fins) formed in a spiral shape as a whole is provided from the side of the cylindrical body 62 toward the inner wall of the side 61a of the cylinder chamber. Each fin of the fin group 63 is attached so as to be substantially parallel to the horizontal plane. Each fin has substantially the same angle formed in a direction in which adjacent fins are directed with respect to the central axis of the cylindrical body 62. In the present embodiment, as shown in FIG. 2, the fin group 63 is composed of nine fins, and the angle formed in the direction in which adjacent fins are directed is constant at 45 degrees. In the plan view of FIG. 2A, two fins are overlapped, and eight fins are visually recognized.
Further, as shown in FIG. 2B, each fin of the fin group 63 is attached to the cylindrical body 62 so that the fin group 63 as a whole is spiral.

  The bottom 61c of the cylinder chamber 61 is provided with a drain hole 66 for discharging moisture separated from the introduced air to the outside.

  Next, the operation of the evaporated fuel processing apparatus 1 will be described with particular attention to the operation of the separator 6.

  When the control unit 4 decides to execute the purge process according to the engine operating conditions, it sends a purge control signal P_CTL indicating “purge execution” to the purge control valve 30. As a result, the purge control valve 30 is opened.

  When the purge control valve 30 is in the open state, the negative suction pressure in the intake pipe 5 acts on the canister 3, so that the air outside the vehicle is ventilated after moisture and / or dust is removed (separated) by the separator 6. It is introduced into the canister 3 through the mouth 3a. The evaporated fuel adsorbed in the canister 3 is desorbed by the introduced air, and the purge gas containing the desorbed evaporated fuel is sucked into the intake pipe 5 through the purge passage 11, and then the combustion of the engine Combustion processing (purge processing) is performed indoors.

Here, the flow of air in the separator 6 will be described with reference to FIG. FIG. 4 is a top view and a side view of the separator 6 as in FIG. 2, but the air flow is indicated by arrows.
In FIG. 4, the air outside the vehicle is introduced into the cylinder chamber 61 from the air passage 13 through the inflow port 64 and the opening 64a. Since the outflow port 65 is provided above the inflow port 64, the introduced air moves down the donut-shaped space formed by the inner wall of the side portion 61 a of the cylinder chamber 61 and the side portion of the cylindrical body 62. It will go upwards. At that time, since the fin group 63 formed in a spiral shape as a whole is provided on the side portion of the cylindrical body 62, the introduced air does not go to the outflow port 65 immediately, but along the fin group 63. To rise. That is, the air flow in the cylinder chamber 61 has a spiral shape as shown in FIG.

As described above, according to the evaporated fuel processing apparatus 1 according to the present embodiment, the air flow in the cylinder chamber 61 is spiral in the separator 6, so the residence time of air in the cylinder chamber 61 is made as long as possible. In addition, during the stay period, heavy moisture and dust fall onto the bottom 61c of the cylinder chamber 61, so that high separation performance is ensured.
Further, since the separator 6 in the fuel vapor processing apparatus 1 is not a filter system, the pressure loss before and after the separator 6 is small, and a sufficient purge air amount can be secured.

<Modification>
Next, a separator 7 that is a modification of the separator 6 will be described with reference to FIG. FIG. 5 is a view showing a modification of the separator in the present embodiment. The separator 7 shown in FIG. 5 differs from the separator 6 only in the configuration of the fin group.
The fin group 63 described above is formed in a spiral shape as a whole, but the fin group 73 in the separator 7 is formed in a propeller shape. That is, each fin is attached to the cylindrical body 62 at an angle upward with respect to the horizontal plane, and a plurality of propellers (three layers in FIG. 5) are laminated by four fins.
In this modification, the fin group 73 has a propeller shape, that is, each fin is angled upward with respect to the horizontal plane, so that the air flow introduced from the inflow port 64 is swirled in the cylinder chamber 61. It becomes a shape. Therefore, the separator 7 assures high separation performance like the separator 6.

<Second Embodiment>
Hereinafter, embodiments of the present invention will be described. The evaporated fuel processing apparatus of this embodiment differs from the evaporated fuel processing apparatus of the first embodiment only in the separator.

  Hereinafter, the separator 8 of this fuel vapor processing apparatus will be described with reference to the drawings. FIG. 6 shows (a) a top view and (b) a side view of a separator in the evaporated fuel processing apparatus according to the present embodiment. FIG. 7 is a cross-sectional view taken along line CC in FIG. In the following description, the same parts as those of the separator 6 of the first embodiment are denoted by the same reference numerals, and redundant description is not performed.

This separator 8 is different from the separator 6 in that a pipe portion 82 having the functions of the inflow port 64 and the cylindrical body 62 in the separator 6 described above is provided. The pipe portion 82 has a hollow shape with both ends open, and is connected to the air passage 13 (see FIG. 1) on the opening 82a side outside the cylinder chamber 61. The pipe portion 82 extends horizontally from the open end 82a to the central axis of the cylinder chamber 61, bends downward at the bending portion 82b, and is joined to the cylinder chamber 61 at the upper portion 61b. The pipe part 82 extends from the joining position to the other opening end 82c (first inlet) concentrically with the cylinder chamber 61.
A portion of the pipe portion 82 inside the cylinder chamber 61 is a hollow cylindrical body. Similar to the cylindrical body 62 of the separator 6 described above, the fin group 63 is provided for the hollow cylindrical body.

Next, the flow of air in the separator 8 will be described with reference to FIG. FIG. 8 is a top view and a side view of the separator 8 as in FIG. 6, but the air flow is indicated by arrows.
In FIG. 8, the air outside the vehicle is introduced into the cylinder chamber 61 from the open end 82 c via the pipe portion 82. Since the air introduced into the cylinder chamber 61 is directed downward from above, it moves upward after colliding with the bottom 61c of the cylinder chamber 61.

  The subsequent air flow is the same as that of the separator 6 in the first embodiment. That is, after that, air goes upward in the donut-like space formed by the inner wall of the side portion 61a of the cylinder chamber 61 and the side portion of the hollow cylindrical portion of the tube portion 82. At that time, since the fin group 63 formed in a spiral shape as a whole is provided on the side portion of the cylindrical body 62, the introduced air does not immediately go to the outflow port 65 but along the fin group 63. To rise. That is, the air flow in the cylinder chamber 61 has a spiral shape as shown in FIG.

As described above, in the fuel vapor processing apparatus according to the present embodiment, the air flow in the cylinder chamber 61 is spiral in the separator 8, so the residence time of air in the cylinder chamber 61 can be made as long as possible. Similar to the fuel vapor processing apparatus 1 of the first embodiment, a high separation performance is ensured by dropping heavy moisture and dust onto the bottom 61c of the cylinder chamber 61 during the stay period.
Further, in this fuel vapor processing apparatus, the pipe portion 82 is a hollow cylindrical body inside the cylinder chamber 61, and air is introduced into the cylinder chamber 61 through the lower open end 82 c of the hollow cylindrical body. Therefore, the separation performance is further improved by the gravity effect of the air flow in the hollow cylindrical body.

  The embodiment of the present invention has been described in detail above, but the specific configuration and system are not limited to the present embodiment, and design modifications and other systems can be made without departing from the scope of the present invention. This includes adaptations.

It is a schematic block diagram of the evaporative fuel processing apparatus which concerns on embodiment. It is the upper side figure and side view of the separator in 1st Embodiment. It is sectional drawing of the separator in 1st Embodiment. It is a figure for demonstrating operation | movement of the separator in 1st Embodiment. It is a figure which shows the flow of the air of the separator in 1st Embodiment. It is the upper side figure and side view of the separator in 2nd Embodiment. It is sectional drawing of the separator in 2nd Embodiment. It is a figure which shows the flow of the air of the separator in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Evaporative fuel processing apparatus 2 ... Fuel tank 3 ... Canister 4 ... Control unit 5 ... Intake pipe 6 ... Separator 61 ... Cylinder chamber 62 ... Cylindrical body 63 ... Fin group (multiple fins)
64 ... Inflow port (first inlet)
65 ... Outflow port (first outlet)
66 ... Drain hole 10 ... Evaporated fuel passage (first passage)
11 ... Purge passage (second passage)

Claims (4)

An evaporative fuel processing apparatus for a vehicle equipped with an internal combustion engine,
A canister that adsorbs the evaporated fuel generated in the fuel tank;
A first passage connecting the fuel tank and the canister;
A second passage connecting the canister and an intake passage of the internal combustion engine;
A third passage connecting the outside of the vehicle and the canister;
A separator provided in the third passage for separating moisture and / or dust contained in air introduced from the outside of the vehicle,
The separator is
A cylinder chamber closed at the top and bottom;
A first inlet for inflowing air;
A first outlet that is on a side of the cylinder chamber and disposed at a higher position than the first inlet, and flows out air to the canister;
A cylindrical body provided substantially concentrically with the cylinder chamber from the top of the cylinder chamber to at least the first outlet in the central axis direction of the cylinder chamber;
An evaporative fuel processing apparatus, comprising: a plurality of fins that are provided from the side of the cylindrical body toward the inner wall of the side of the cylinder chamber and are formed in a spiral shape as a whole. The evaporated fuel processing apparatus according to claim 1, wherein the fin is substantially parallel to a horizontal plane. The evaporated fuel processing apparatus according to claim 1, wherein the fin is angled upward with respect to a horizontal plane. The evaporative fuel processing apparatus according to claim 1, wherein the cylindrical body is a hollow cylindrical body, and the first inflow port is formed by an opening end on a lower side of the hollow cylindrical body. .

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