JP2018188985A - Evaporated fuel treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress too quick purge of high-concentration evaporated fuel from a tank port while allowing the flow of the evaporated fuel from a region on the tank port side of an adsorption chamber to a region on the purge port side.SOLUTION: A canister 10 includes a case 12 forming an adsorption chamber 18, and adsorbent 22 filled in the adsorption chamber 18. In the case 12, a tank port 26 and a purge port 27 are parallelly provided. In the case 12, a paper guide 30 is provided for partitioning the end on the port side of the adsorption chamber 18 into a region 26T and a region 27T. At the side end of the paper guide 30, a cutout 36 is formed to communicate the region 26T and the region 27T. A shortest distance D1 between a center 27C of the purge port 27 and the cutout 36 is longer than a shortest distance D2 between the center 27C of the purge port 27 and a front end 30a of the paper guide 30.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fuel vapor processing apparatus.

  The evaporative fuel processing apparatus includes a canister that adsorbs evaporated fuel (vapor) evaporated from a fuel tank for a vehicle and purges the fuel when the engine is operating (see, for example, Patent Document 1). FIG. 8 is a cross-sectional view showing the main part of the canister. As shown in FIG. 8, a filling chamber (corresponding to “adsorption chamber”) 112 is formed in a casing (corresponding to “case” in the present specification) 102. The filling chamber 112 is filled with activated carbon (corresponding to “adsorbent”) 111. The casing 102 is provided with a charge port (corresponding to “tank port”) 106 and a purge port (corresponding to “purge port”) 105 in parallel. The charge port 106 communicates with the filling chamber 112 via a first screen member (corresponding to a “filter member”) 114. The purge port 105 communicates with the filling chamber 112 via a second screen member (corresponding to a “filter member”) 115. The casing 102 is provided with a partition wall (corresponding to a “vapor guide”) 116 that partitions the port side end of the filling chamber 112 into a charge port side region 106t and a purge port side region 105t. Yes. A groove-shaped notch 134 that allows the flow of evaporated fuel from the charge port side region 106t to the purge port side region 105t is formed at the tip of the partition wall 116.

JP 2006-348847 A

  According to the conventional example (see Patent Document 1), since the notch 134 is formed in the partition wall 116, the shortest distance d1 between the center of the purge port 105 and the notch 134 is equal to the distance between the purge port 105 and the partition wall 116. It is shorter than the shortest distance d2 between the front end 116a. For this reason, at the time of purging the evaporated fuel (hereinafter referred to as “purging”), the high-concentration evaporated fuel from the charge port 106 is likely to pass through the notch 134 and is difficult to bypass the front end 116 a of the partition wall 116. Therefore, high-concentration evaporated fuel from the charge port 106 is likely to be purged in a short circuit to the purge port 105 through the notch 134. This is not preferable because desorption of the evaporated fuel from the activated carbon 111 in both the regions 105t and 106t becomes insufficient and the air-fuel ratio of the engine is disturbed.

  The problem to be solved by the present invention is to allow short-circuit purge of high-concentration evaporated fuel from the tank port while allowing the flow of evaporated fuel from the tank port side region of the adsorption chamber to the purge port side region. An object of the present invention is to provide an evaporative fuel treatment device that can be suppressed.

  The above-described problem can be solved by the evaporated fuel processing apparatus of the present invention.

  A first invention includes a case that forms an adsorption chamber, and an adsorbent that is filled in the adsorption chamber and that adsorbs and desorbs the evaporated fuel. And a purge port for purging the evaporated fuel in the adsorption chamber are provided in parallel, and the end of the adsorption chamber on the port side is purged with an area on the tank port side. An evaporative fuel processing apparatus provided with a wall-like vapor guide that divides into a port-side region, wherein a side end portion of the vapor guide includes a region on the tank port side and a region on the purge port side. And a shortest distance between the center of the purge port and the notch is longer than a shortest distance between the center of the purge port and the tip of the vapor guide. , It is calling the fuel processing system.

  According to the first invention, the flow of the evaporated fuel from the tank port side region of the adsorption chamber to the purge port side region can be permitted by the notch formed in the side end portion of the vapor guide. The shortest distance between the center of the purge port and the notch of the vapor guide is longer than the shortest distance between the center of the purge port and the tip of the vapor guide. For this reason, at the time of purging, the high-concentration evaporated fuel from the tank port is unlikely to pass through the notch and easily bypass the tip of the vapor guide. Therefore, it is possible to suppress short-circuit purging of high-concentration evaporated fuel from the tank port.

  According to a second invention, in the first invention, the case has a three-body structure including an intermediate member, one end member, and the other end member, and the one end member includes the tank port and the purge port. This is an evaporative fuel processing apparatus in which a vapor guide is integrally formed.

  According to the second invention, since the vapor guide is integrally formed with the tank port and the purge port on the one end member of the three-body structure case, the vapor guide is formed as a separate part and is welded to the case, bonded, etc. Compared with the case of attachment, the number of parts and assembly man-hours can be reduced.

  According to the evaporative fuel processing apparatus of the present invention, short-circuit purging of high-concentration evaporative fuel from the tank port is allowed while allowing the evaporative fuel to flow from the tank port side region of the adsorption chamber to the purge port side region. Can be suppressed.

1 is a cross-sectional view schematically showing a canister according to Embodiment 1. FIG. It is the II-II sectional view taken on the line of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. It is sectional drawing which shows typically the peripheral part of the vapor guide of a canister. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4. It is sectional drawing which shows typically the canister concerning Embodiment 2. FIG. It is sectional drawing which shows the principal part of the canister concerning a prior art example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1] In this embodiment, a canister as an evaporative fuel processing apparatus installed in a vehicle such as an automobile equipped with an engine as an internal combustion engine is illustrated. After explaining the outline of the canister, the main part will be explained. 1 is a cross-sectional view schematically showing the canister, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. For convenience of explanation, the upper, lower, left and right sides of the canister are determined with reference to FIG. The direction of mounting the canister with respect to the vehicle is set as appropriate.

  As shown in FIG. 1, the canister 10 includes a long rectangular box-shaped case 12. The case 12 is made of resin, and includes a bottomed square cylindrical case main body 13 and a lid member 14 that closes an opening end of the case main body 13. That is, the case 12 has a two-body structure including a case main body 13 and a lid member 14. The case main body 13 has a cylindrical tube portion 13a and an end wall portion 13b that closes one end surface (left end surface in FIG. 1) of the tube portion 13a. The other end surface (opening end surface) of the cylindrical portion 13a of the case body 13 and the outer peripheral portion of the lid member 14 are joined by joining means such as thermal welding and adhesion.

  The inside of the case body 13 is partitioned into two upper and lower chambers by a partition wall 16. The upper chamber is referred to as a first adsorption chamber 18, and the lower chamber is referred to as a second adsorption chamber 20. Each of the adsorption chambers 18 and 20 is filled with a granular adsorbent 22 that adsorbs and desorbs the evaporated fuel. The granular adsorbent 22 is made of crushed activated carbon (crushed coal), granulated coal obtained by granulating granular or powdered activated carbon together with a binder, and the like. Both the suction chambers 18 and 20 are connected to each other by a connection path 24 formed between the case main body 13 and the lid member 14. Thus, a U-shaped flow structure passage that connects the first adsorption chamber 18 and the second adsorption chamber 20 via the connection path 24 is formed.

  A tank port 26 and a purge port 27 that communicate with the first adsorption chamber 18 and an atmospheric port 28 that communicates with the second adsorption chamber 20 are formed on the end wall portion 13 b of the case body 13. The tank port 26 is a port for introducing the evaporated fuel from the fuel tank (specifically, the gas layer in the tank) to the first adsorption chamber 18. The purge port 27 is a port for purging the evaporated fuel in the first adsorption chamber 18 to the engine (specifically, the intake passage). The atmospheric port 28 is open to the atmosphere. The tank port 26, the purge port 27, and the atmospheric port 28 are provided in parallel in the vertical direction. Each port 26, 27, 28 is formed in a cylindrical shape (see FIG. 3).

  The case 12 is provided with a flat wall-shaped vapor guide 30 that vertically partitions the end of the first adsorption chamber 18 on the port side (end wall portion 13b side) (see FIGS. 2 and 3). The vapor guide 30 partitions the end of the first adsorption chamber 18 on the port side (end wall portion 13b side) into a tank port side region 26T and a purge port side region 27T (see FIG. 3).

  A sheet having air permeability between the tank port 26 and the tank port side region 26T, between the purge port 27 and the purge port side region 27T, and between the atmospheric port 28 and the second adsorption chamber 20. The filter members 32 are arranged so as to partition each other. Each filter member 32 is made of urethane foam, nonwoven fabric, or the like, and holds the adsorbent 22 in each of the adsorption chambers 18 and 20. Moreover, each filter member 32 is arrange | positioned on the same plane.

  Arranged in the openings on the other end side (lid member 14 side) of the first adsorption chamber 18 and the second adsorption chamber 20 so that the porous plate 34 formed by laminating a sheet-like filter having air permeability is closed. Has been. The perforated plate 34 holds the adsorbent 22 in each of the adsorption chambers 18 and 20.

  The operation of the canister 10 will be described. At the time of adsorption of the evaporated fuel (hereinafter referred to as “at the time of adsorption”), the evaporated fuel from the fuel tank is introduced into the first adsorption chamber 18 from the tank port 26. The evaporated fuel is adsorbed by the adsorbent 22 when passing through the first adsorption chamber 18 and the second adsorption chamber 20. Finally, air that does not contain evaporative fuel or air that contains almost no fuel is released from the atmosphere port 28 to the atmosphere.

  Further, when purging, the intake negative pressure of the engine is introduced into the first adsorption chamber 18 from the purge port 27, so that air in the atmosphere flows in a direction opposite to the flow of evaporated fuel at the time of adsorption. Therefore, when the air passes through the second adsorption chamber 20 and the first adsorption chamber 18, the evaporated fuel is desorbed from the adsorbent 22 and is purged from the purge port 27 to the engine.

  Next, the main part of the canister 10 will be described. 4 is a cross-sectional view schematically showing the periphery of the vapor guide of the canister, FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4, and FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. As shown in FIG. 5, the notch part 36 is formed in the line symmetrical form at the both-ends part (upper and lower both ends in FIG. 5) of the vapor guide 30 (refer FIG. 6). The two notches 36 are formed from the both ends of the vapor guide 30 and the both side walls 13a of the first suction chamber 18 of the case 12 from the front end side (right end side in FIG. 5) of the both end portions of the vapor guide 30. It is formed in a long rectangular groove shape extending toward the end (left end in FIG. 5). The front ends (left end in FIG. 5) of both cutout portions 36 are arranged at a position spaced apart from the filter member 32 by a predetermined distance. Both notches 36 penetrate the vapor guide 30 in the plate thickness direction, and both notches 36 communicate the region 26T on the tank port side of the first adsorption chamber 18 with the region 27T on the purge port side. (See FIGS. 4 and 6).

  As shown in FIG. 5, the shortest distance D1 between the center 27C of the purge port 27 and the notch 36 of the vapor guide 30 is the shortest distance between the center 27C of the purge port 27 and the tip 30a of the vapor guide 30. Longer than D2. That is, the outer dimensions of the vapor guide 30 and the dimensions of the notch 36 are set so as to satisfy the relationship D1> D2. In addition, each figure is shown typically and does not correspond in dimension.

  According to the canister 10 described above, the flow of the evaporated fuel from the tank port side region 26T of the first adsorption chamber 18 to the purge port side region 27T can be permitted by the both notches 36 of the vapor guide 30. For this reason, at the time of adsorption, it is possible to increase the amount of evaporated fuel adsorbed by the adsorbent 22 in the purge port side region 27T while reducing the amount of adsorbed fuel 22 adsorbed by the adsorbent 22 in the region 26T on the tank port side. .

  Further, the shortest distance D1 between the center 27C of the purge port 27 and the notch 36 of the vapor guide 30 is longer than the shortest distance D2 between the center 27C of the purge port 27 and the tip 30a of the vapor guide 30. For this reason, at the time of purging, the high-concentration evaporated fuel from the tank port 26 does not easily pass through the notch 36 and easily bypasses the tip 30a of the vapor guide 30. Therefore, a short-circuit purge of the high concentration evaporated fuel from the tank port 26 can be suppressed. As a result, the concentration of the high-concentration evaporated fuel from the tank port 26 is annealed in both regions 26T and 27T, thereby promoting the desorption of the adsorbent 22 in the vicinity of the tank port 26, while evaporating fuel purged to the engine. Therefore, the air-fuel ratio of the engine can be stabilized.

  Unlike the conventional example, the filter member 32 in the region 26T on the tank port side of the first adsorption chamber 18 is not offset to the opposite side to the port side. For this reason, a decrease in the capacity of the adsorbent 22 in the tank port side region 26T can be avoided, and a decrease in the adsorption performance of the canister 10 due to a decrease in the capacity of the adsorbent 22 can be suppressed.

[Embodiment 2] Since this embodiment is a modification of the case 12 of the canister 10 of Embodiment 1, the changed portion will be described, and the same parts as those in Embodiment 1 are denoted by the same reference numerals. The description is omitted. FIG. 7 is a cross-sectional view schematically showing the canister. As shown in FIG. 7, the case main body (indicated by reference numeral 41) in the case (indicated by reference numeral 40) of the present embodiment includes a cylindrical member 42 and an end member 43. Thus, the case 40 has a three-body structure including a cylindrical member 42, an end member 43, and a lid member (reference numeral 44).

  The cylinder member 42 is formed in a square cylinder shape. The end member 43 is a member that closes one opening end portion (opening end portion opposite to the lid member 44 side) of the cylindrical member 42. The end member 43 has an end wall portion 43a and a rectangular tubular peripheral wall portion 43b extending from the outer peripheral portion of the end wall portion 43a to the cylindrical member 42 side (right side in FIG. 7). A vapor guide 30 is formed integrally with the tank port 26, the purge port 27, and the atmospheric port 28 on the end wall portion 43a. In addition, the partition 16 (refer FIG. 1) may be formed in the end wall part 43a or the cylindrical member 42, and may be divided and formed in the end wall part 43a and the cylindrical member 42.

  Opposing end portions of one end portion (left end portion in FIG. 7) of the cylindrical member 42 and the peripheral wall portion 43b of the end member 43 are joined by joining means such as heat welding and adhesion. Moreover, the other end part of the cylinder member 42 and the outer peripheral part of the cover member 44 are joined by joining means such as heat welding and adhesion. The cylindrical member 42 corresponds to an “intermediate member” in this specification. Further, the end member 43 corresponds to the “one end member” in this specification. The lid member 44 corresponds to the “other end member” in this specification.

  According to this embodiment, the vapor guide 30 is integrally formed with the tank port 26 and the purge port 27 on the end member 43 of the case 40 having a three-body structure. For this reason, compared with the case where the vapor guide 30 is comprised by another component and it attaches to the case main body 41 of the case 40 by welding, adhesion | attachment, etc., a number of parts and an assembly man-hour can be reduced. Further, by dividing the case main body 41 into the cylindrical member 42 and the end member 43 and molding the mold, it is possible to reduce the size of the mold for molding the members 42 and 43.

[Other Embodiments] The present invention is not limited to the above-described embodiments, and can be modified without departing from the present invention. For example, the vapor guide 30 may have a wall shape that partitions the first adsorption chamber 18 into a tank port side region 26T and a purge port side region 27T. For example, the vapor guide 30 has a curved wall shape surrounding the axis of the tank port 26. But you can. Further, the shape, the number, and the like of the notch portions 36 of the vapor guide 30 may be changed as appropriate. Further, the number of the first adsorption chambers 18 of the canister 10 may be increased or decreased as appropriate.

10 Canister (evaporative fuel treatment device)
12 Case 14 Lid member 18 First adsorbing chamber 22 Adsorbent 26 Tank port 26T Tank port side area 27 Purge port 27C Center 27T Purge port side area 30 Vapor guide 30a Tip 36 Notch 40 Case 42 Cylindrical member (intermediate member) )
43 End member (one end member)
44 Lid member (other end member)
D1 Shortest distance D2 Shortest distance

Claims (2)

A case forming an adsorption chamber;
An adsorbent filled in the adsorption chamber to adsorb and desorb evaporated fuel;
With
In the case, a tank port for introducing evaporated fuel into the adsorption chamber and a purge port for purging the evaporated fuel in the adsorption chamber are provided in parallel.
The evaporative fuel processing apparatus, wherein the case is provided with a wall-like vapor guide that partitions the port side end of the adsorption chamber into a tank port side region and a purge port side region,
At the side end of the vapor guide, a notch is formed to communicate the tank port side region and the purge port side region,
The evaporative fuel processing apparatus, wherein the shortest distance between the center of the purge port and the notch is longer than the shortest distance between the center of the purge port and the tip of the vapor guide. It is an evaporative fuel processing apparatus of Claim 1, Comprising:
The case has a three-body structure including an intermediate member, one end member, and the other end member.
The evaporated fuel processing apparatus, wherein the vapor guide is integrally formed with the one end member together with the tank port and the purge port.

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