CANISTER

Abstract

 In a canister which includes a main chamber and a sub chamber divided by a partition plate and has an atmosphere port 14 formed on the upper surface of the sub chamber and communicating with the atmosphere and is used to process fuel vapor evaporated from the fuel tank of a vehicle, a first groove 15 is formed in such portion of the upper surface thereof as exists around the atmosphere port 14, two second grooves 16a and 16b are formed in the upper surface with their one-side ends connected to the first groove 15 and their other ends extended to the side surface of the canister, and a cap 18 having a wall portion 18c for closing one of the second grooves 16a and 16b is attached on the atmosphere port 14.

Description

Technical Field

[0001] The invention relates to a canister for processing fuel vapor evaporated from a vehicle fuel tank.

Background Art

[0002] A canister is an apparatus which, using absorbent such as activated carbon, absorbs fuel vapor (such as gasoline vapor) evaporated from a vehicle fuel tank and stores it therein, and discharges the stored fuel into the intake passage of an engine by purging.

Citation List

Patent Document

[0003] [Patent Document 1] Japanese Utility Model Publication No. 02-34750

Summary of Invention

Technical Problem

[0004] A canister includes a port connected to the fuel tank, a port (such as an intake manifold) connected to the intake passage of an engine, and a port (which is hereinafter called an atmosphere port) communicating with the atmosphere. Normally, fuel does not leak from the atmosphere port. However, when an abnormality occurs in a part such as a valve within the fuel tank, there is a fear that the fuel can leak from the atmosphere port.

[0005] In a canister having its atmosphere port covered with a cap, since, when fuel leaks, the fuel flows along the side surface of the canister, the canister cannot restrict the fuel leakage passage and drop position. Meanwhile, in a canister having its atmosphere port connected to a connecter and a hose to thereby restrict the drop position of the fuel, the increased number of parts leads to the increased manufacturing cost.

[0006] The invention aims at solving the above problems and thus has an object to provide a canister which can restrict the leakage passage of the fuel at low manufacturing cost with reduced number of parts.

Solution to Problem

[0007] According to the invention, there is provided a canister for processing fuel vapor evaporated from a fuel tank of a vehicle, comprising:

first and second chambers divided by a partition plate; and

an atmosphere port arranged on an upper surface of the first chamber or the second chamber and communicating with the atmosphere,

the canister characterized in that:

a first groove is formed in a portion of the upper surface around the atmosphere port,

at least two second grooves are formed in the upper surface, wherein one-side ends thereof are connected to the first groove and the other side ends thereof are extended to a side surface of the canister, and

a cap having a wall portion closing at least one of the second grooves is attached on the atmosphere port.

[0008] The atmosphere port may have a cylindrical shape. The one-side ends of the second grooves may respectively be connected to the first groove at a point. The wall portion of the cap may be directed in a direction to pass through the center of the atmosphere port. The wall portion of the cap may be extended through the first groove to a position for closing the one-side ends of the second grooves.

[0009] The second grooves may be constituted of two grooves, and the two grovoes may be arranged in a straight line.

[0010] The second grooves may also be formed in a portion of the upper surface disposed on the partition plate.

Advantageous Effects of Invention

[0011] According to the invention, since fuel leaked through the atmosphere port firstly flows into the first groove and then flows into the second grooves connected to the first groove, the flow direction of the fuel leaked from the atmosphere port can be restricted. This can enhance the freedom of the layout of vehicle parts arranged around the canister.

[0012] Since the other-side ends of the second grooves extend to the side surface of the canister and at least one of the second grooves is closed by the wall portion of the cap attached on the atmosphere port, the fuel leaked from the atmosphere port is not allowed to stay in the first and second grooves but can be guided quickly in a specific direction, thereby enabling further restriction of the flow direction of the fuel.

[0013] The one-side ends of the second grooves are connected at a point to the annular-shaped first groove formed in the periphery of the cylindrical-shaped atmosphere port, and the wall portion of the cap is directed in a direction to pass through the center of the atmosphere port and extends through the first groove to a position for closing the one-side ends of the second grooves. Thus, the wall portion of the cap passes through the first groove to separate it and closes one end of one of the second grooves, thereby enabling still further restriction of the fuel flow direction.

[0014] Also, since, simply by rotating the cap, one end of an arbitrary one of the second grooves can be closed by the wall portion, an arbitrary groove can be restricted by the same cap. Thus, while using the same canister for multiple vehicles having different layouts, the optimum fuel flow passage can be set for the respective vehicles.

[0015] Since the second grooves are constituted of two grooves and they are arranged to provide a straight line, groove formation in the canister upper surface is simplified, thereby enabling enhancement in the productivity.

[0016] Since the second grooves are formed in such portion of the upper surface of the canister as exists on the partition plate, the reduced thickness of the canister upper surface caused by groove formation can be prevented. Also, since the groove can be formed in the canister upper surface without adding a reinforcing member to the interior thereof, the canister interior structure can be simplified.

[0017] As described above, according to the invention, in a canister for use in vehicles, the leakage passage of fuel can be restricted at low manufacturing cost with reduced number of parts.

Brief Description of Drawings

[0018] 

Fig. 1 is an explanatory view of a canister according to the invention. Fig. 1(a) is a perspective view and Fig. 1(b) is a top view.

Fig. 2 is an explanatory view of a cap to be attached onto the canister of the invention. Fig. 2(a) is a perspective view, Fig. 2(b) is a side view, and Fig. 2(c) is a front view.

Fig. 3 is a perspective view of the canister of the invention, explaining an example for mounting a cap thereon.

Fig. 4 is a perspective view of the canister of the invention, explaining another example for mounting a cap thereon.

Fig. 5 is a top view of the cap of the canister shown in Fig. 3.

Fig. 6 is a top view of the cap of the canister shown in Fig. 4.

Fig. 7 is a perspective view of the canister of the invention, explaining how to mount it onto a vehicle body.

Description of Embodiments

[0019] Description is given below of an embodiment of a canister of the invention with reference to Figs. 1 to 7.

(Embodiment 1)

[0020] Fig. 1 is an explanatory view of a canister according to this embodiment, while Fig. 1(a) is a perspective view and Fig. 1 (b) is a top view. Fig. 2 is an explanatory view of a cap to be attached onto the canister of this embodiment, while Fig. 2(a) is a perspective view, Fig. 2(b) is a side view, and Fig. 2(c) is a front view. Figs. 3 and 4 are perspective views of the canister and cap of this embodiment, respectively explaining examples for mounting the cap onto the canister. Fig. 5 is a top view of the cap of the canister shown in Fig. 3. Fig. 6 is a top view of the cap of the canister shown in Fig. 4. Fig. 7 is a perspective view of the canister of this embodiment, explaining how to mount it onto a vehicle body.

[0021] The canister 10 of this embodiment, using absorbent such as activated carbon, absorbs fuel vapor (such as gasoline vapor) evaporated from a vehicle fuel tank (not shown), stores it therein and discharges the stored fuel into the intake passage (such as an intake manifold (not shown)) of an engine by purging.

[0022] The upper surfaces 11 a and 11b of a housing 11 of the canister 10 have a substantially circular shape, the side surface (outer peripheral surface) of the housing 11 has a cylindrical shape and, as a whole, it has a cylindrical shape. The cylindrical shape of the side surface 11c enhances the wall surface rigidity of the side surface 11c. Also, the canister 10 is formed as an integral body except for its bottom surface (not shown). After the absorbent is supplied into the canister 10, the bottom surface is welded to the lower portion of the side surface 11c to thereby form the canister 10. In the lower portion of the side surface 11 c, there is formed a flange-shaped welded portion 11 e.

[0023] Although not shown, the interior of the canister 10 is divided by a partition plate to a main chamber (first room) and a sub chamber (second room). In the main and sub chambers, there is charged absorbent such as activated carbon. The partition plate, when viewed from the upper surfaces 11 a and 11 b, is arranged in a straight line such that the main chamber is larger in area than the sub chamber. That is, the partition plate is arranged to divide the cylindrical canister 10 vertically so that the volume of the main chamber is larger than that of the sub chamber. Here, the partition plate does not extend to the bottom surface of the canister 10 but the main and sub chambers communicate with each other in the lower portion of the canister 10.

[0024] In the upper surface 11 a where the main chamber of the canister 10 exists, there are formed a tank port 12 communicating with the main chamber and connected to the fuel tank, and a purge port 13 communicating with the main chamber and connected to the intake passage of the engine. The purge port 13 is disposed in the center (for example, area center) of the upper surface 11a. The purge port 13 is disposed at a position most distant from the side surface 11c of the canister 10 and partition plate.

[0025] In the upper surface 11 b where the sub chamber of the canister 10 exists, there is formed an atmosphere port 14 allowing the sub chamber and the atmosphere to communicate with each other. The atmosphere port 14 is situated on a diameter line (not shown) bisecting the sub-chamber-side upper surface 11 b.

[0026] In such portion of the upper surface 11 b as exists around the atmosphere port 14, along the outer periphery of the atmosphere port 14, there is formed a first groove 15 constituting the leakage passage of fuel. Further, there is formed a second groove 16 constituting the fuel leakage passage such that it is connected to the first groove 15.

[0027] The atmosphere port 14 has a cylindrical shape, while the first groove has an annular shape. The second groove 16 includes two second grooves 16a and 16b. The one-side ends of the second grooves 16a and 16b are respectively connected to the first groove 15 at a connecting point. The other ends of the second grooves 16a and 16b are respectively extended to the side surface 11c of the canister 10, whereby fuel leaked out from the atmosphere port 14 is not allowed to stay in the first and second grooves 15 and 16 but can be guided quickly.

[0028] The second grooves 16a and 16b are extended in the same direction to provide a straight line, thereby forming a single second groove 16. The second groove 16 is constituted of the two second grooves 16a and 16b and they are arranged to provide a straight line, thereby enabling easy formation of the second grooves 16a and 16b in the upper surface of the canister 10 and thus enabling enhancement in the productivity of the canister 10.

[0029] The second groove 16 is formed in the upper surface of the canister 10 providing the upper side of the partition plate. Thus, the reduced thickness of the upper surface caused by formation of the second groove 16 can be prevented. Therefore, the second groove 16 can be formed in the upper surface of the canister 10 without adding a reinforcing member to the inside thereof, thereby enabling simplification of the internal structure of the canister 10. Also, when the canister 10 is formed of resin, the fluidity of the resin can be enhanced, thereby enabling enhancement in the productivity of the canister 10.

[0030] The first and second grooves 15 and 16 can be formed as an integral body together with the upper surfaces 11 a, 11 b constituting the housing 11 of the canister 10, partition plate and the like.

[0031] The upper surface 11 b includes, around the first groove 15, multiple pawls 17. The pawls 17 are used to mount a cap 18 shown in Fig. 2 onto the atmosphere port 14. The cap 18 covers the atmosphere port 14 from above and around to prevent entry of foreign substances from outside.

[0032] The cap 18 includes a cap main body 18a for covering the atmosphere port 14 from above and around, an extension portion 18b extended from the cap main body 18a for covering a portion of the second groove 16 from above, and a wall portion 18c vertically extended from the extension portion 18b for closing the end of one of the second grooves 16a and 16b. The wall portion 18c, as shown in Fig. 5, is arranged, when viewed from above, to extend in a direction Lc passing through the center of the atmosphere port 14. The wall portion 18c extends through the first groove 15 to a position for closing one end of the second groove 16a.

[0033] As shown in Figs. 3 and 5, while attaching the cap 18 onto the atmosphere port 14, when the wall portion 18c passes through the first groove 15 and is inserted into one end (in Fig. 3, this side end; in Fig. 5, right side end) of the second groove 16a, the second groove 16a is closed. In its top view, when the wall portion 18c is inserted obliquely to the longitudinal direction of the second groove 16a, the wall portion 18c closes one end of the second groove 16a and separates the first groove 15, thereby enabling more positive closing of the second groove 16a and thus enabling further restriction of the fuel flow direction.

[0034] In the above structure, when an abnormality occurs in a part such as a valve within the fuel tank and the fuel leaks from the atmosphere port 14, firstly, the leaking fuel flows into the first groove 15 and, after then, is guided by the second groove 16b toward the side surface 11c which exists on the deep side in Fig. 3 and on the left side in Fig. 5 (see the dotted line Fb shown in Figs. 3 and 5). Thus, the fuel leakage passage can be restricted at a low manufacturing cost with a reduced number of parts. This can enhance the freedom of the layout of vehicle parts arranged around the canister 10. Also, the fuel leaking from the atmosphere port 14 is not allowed to stay in the first and second grooves 15 and 16 but can be guided quickly in a specific direction.

[0035] In Figs. 3 and 5, the second groove 16a is closed. However, reversely, when it is desired to close the second groove 16b (the deep side in Fig. 3 and the left side in Fig. 5), similarly, the insertion position of the wall portion 18c of the cap 18 may be changed to close one end of the second groove 16b.

[0036] As shown in Figs. 4 and 6, while mounting the cap 18 onto the atmosphere port 14, when the wall portion 18c passes through the first groove 15 and is inserted into one end (in Fig. 4, deep side end; in Fig. 6, left side end) of the second groove 16b, the second groove 16b is closed. In this case as well, in its top view, when the wall portion 18c is inserted obliquely to the longitudinal direction of the second groove 16b, the wall portion 18c closes one end of the second groove 16b and separates the first groove 15, thereby enabling more positive closing of the second groove 16b and thus enabling further restriction of the fuel flow direction.

[0037] In this structure, when an abnormality occurs in a part such as a valve within the fuel tank and the fuel leaks from the atmosphere port 14, firstly, the leaking fuel flows into the first groove 15 and, after then, is guided by the second groove 16a toward the side surface 11c which exists on this side in Fig. 3 and on the right side in Fig. 5 (see the dotted line Fa in Figs. 4 and 6). Thus, the fuel leakage passage can be restricted at a low manufacturing cost with reduced number of parts. This can enhance the freedom of the layout of vehicle parts arranged around the canister 10. Also, the fuel leaking from the atmosphere port 14 is not allowed to stay in the first and second grooves 15 and 16 but can be guided quickly in a specific direction.

[0038] As described above, by turning the cap 18 simply, since one end of arbitrary one of the second grooves 16a and 16b can be closed by the wall portion 18c, an arbitrary groove can be regulated by the same cap 18. Thus, while using the same canister 10 for multiple vehicles having different layouts, the optimum fuel flow passage can be set for the respective vehicles.

[0039] Here, in the above embodiment, the two second grooves 16a and 16b are illustrated. However, the number of second grooves may also be increased. In such case as well, by arranging the second grooves such that one end of arbitrary one of the second grooves can be closed using the wall portion 18c of the cap 18, the fuel leakage passage can be regulated.

[0040] And, the cap 18 may also be structured such that, the cap main body 18a includes in its lower portion a labyrinth structure portion between this portion and the upper surface 11 b. This labyrinth structure includes an uneven portion cooperating with such portion of the upper surface 11 b as exists around the first groove 15 to provide a maze. This structure can prevent the fuel from flowing out from the first groove 15 and can guide the fuel toward the second groove 16 to thereby regulate the fuel leakage passage. Here, the cap 18 has such passage section area as does not worsen pressure loss with respect to the atmosphere port 14 while the cap 18 is absent therein.

[0041] Also, on the side surface 11c existing on the sub chamber side of the canister 10, as shown in Fig. 7 as well, there is provided a reverse-trapezoid-shaped fixing member 31. This fixing member 31 may preferably be disposed on the central portion of the sub-chamber-side side surface 11c, in other words, at a position most distant from the partition plate dividing the main and sub chambers. And, on the body (vehicle body) of the vehicle, there is mounted a reverse-trapezoid-shaped hold member 32. When the fixing member 31 is held by the hold member 32, the canister 10 is fixed to the body.

[0042] In the canister 10, in order to remove fuel vapor adhering to the interior thereof, using the pressure (negative pressure) of the intake manifold of the engine, the purge solenoid valve is opened at a specific cycle to negative-pressure suck the canister 10 from the purge port 13, whereby the fuel vapor adhering to the inside is guided into the intake manifold and the fuel is burnt within the cylinder of the engine for processing the fuel (canister purging).

[0043] In the canister purging, with the opening cycle of the purge solenoid valve, purge pulsation occurs. This purge pulsation can be transmitted to the canister 10 and further to the body with the canister 10 fixed thereto, whereby it can enter the vehicle room as pulsation sounds.

[0044] Conventionally, generally, by modifying the canister mounting method (for example, by disposing the canister in a portion where body sensitivity is low, or by fixing it to a mass member, or by elastically supporting it to reduce the transmission coefficient thereof), or using a pulsation reducing part (a chamber, a purge hose of proper material, or extension of the length of a purge hose), the pulsation sounds are reduced, resulting in a very high cost.

[0045] Thus, while paying attention to the fact that the canister 10 is constituted of main and sub chambers, the inventors, in order to reduce the influence of the pulsation sounds at a low manufacturing cost, as described above, dispose the fixing member 31 of the canister 10, which exists near to the body, on the sub-chamber-side side surface 11c. Especially, when the fixing member 31 is disposed at the position of the side surface 11 c most distant from the partition plate, the influence of the pulsation sounds is smallest. With such arrangement, the structure is simple, the manufacture is easy and the influence of the pulsation sounds can be reduced at a low manufacturing cost.

Industrial Applicability

[0046] The invention is suitable for a canister for use in a vehicle.

Reference Signs

[0047] 

10:

canister

11:

housing

14:

atmosphere port

15:

first groove

16:

second groove

18:

cap

18c:

wall portion

31:

fixing member

Claims

1. A canister for processing fuel vapor evaporated from a fuel tank of a vehicle, comprising:

first and second chambers divided by a partition plate; and

an atmosphere port arranged on an upper surface of the first chamber or the second chamber and communicating with the atmosphere,

the canister characterized in that:

a first groove is formed in a portion of the upper surface around the atmosphere port,

at least two second grooves are formed in the upper surface, wherein one-side ends thereof are connected to the first groove and the other side ends thereof are extended to a side surface of the canister, and

a cap having a wall portion closing at least one of the second grooves is attached on the atmosphere port.

2. The canister according to Claim 1, wherein
the atmosphere port has a cylindrical shape,
the one-side ends of the second grooves are respectively connected to the first groove at a point,
the wall portion of the cap is directed in a direction to pass through a center of the atmosphere port, and
the wall portion of the cap is extended through the first groove to a position closing the one-side ends of the second grooves.

3. The canister according to Claim 2, wherein
the second grooves constituted of two grooves, and the two grooves are arranged in a straight line.

4. The canister according to Claim 3, wherein
the second grooves are formed in a portion of the upper surface disposed on the partition plate.

Drawing