JP2011064101A - Evaporation fuel adsorbent and canister - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an evaporation fuel adsorbent capable of controlling the dropout of a heat storage material, and a canister provided with the evaporation fuel adsorbent. <P>SOLUTION: A heat storage molding 40 is configured by joining and integrating two or more heat storage material capsules 42, that enclose the phase-changing heat storage materials, within a spherical shell-like microcapsule formed of resin, ceramics, or the like. The heat storage molding 40 is built in an activated carbon body 38 formed into a cylindrical shape. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an evaporated fuel adsorber and a canister.

  In a canister for treating evaporated fuel gas generated in a fuel tank or the like, it is desirable to suppress temperature change of activated carbon (evaporated fuel adsorbent). For example, Patent Document 1 describes activated carbon in which a surface is coated with a heat storage material and is fixed, and activated carbon obtained by kneading the heat storage material into a pellet shape.

  However, in the activated carbon of Patent Document 1, since the heat storage material is exposed on the surface of the activated carbon, the exposed heat storage material may fall off when the activated carbon is rubbed and worn by vibration or the like.

JP 2006-207485 A

  This invention considers the said fact and makes it a subject to obtain the evaporative fuel adsorber which can suppress omission of a thermal storage material, and a canister provided with this evaporative fuel adsorber.

  In the first aspect of the present invention, the activated carbon main body formed of activated carbon that adsorbs and desorbs the evaporated fuel and a plurality of heat storage members that suppress the temperature change of the activated carbon main body are integrated and incorporated in the activated carbon main body. And a heat storage molded body.

  In this evaporated fuel adsorbent, the activated carbon main body is formed of activated carbon, and the evaporated fuel is adsorbed and desorbed. Moreover, the heat storage member which comprises a heat storage molded object suppresses the temperature rise of the activated carbon main body at the time of vaporization fuel adsorption | suction, and the temperature fall of the activated carbon main body at the time of vaporization fuel detachment | desorption.

  The plurality of heat storage members are integrated into a heat storage molded body, and are incorporated in the activated carbon main body. That is, all of the plurality of heat storage members are not exposed on the surface of the activated carbon main body or are integrated in a state where the exposed portions are few. Therefore, even when the activated carbon main body is rubbed, dropping of the heat storage member is suppressed.

  Note that the term “built-in” as used herein means that the inner wall of the activated carbon body is located inside, that is, the heat storage member is not exposed to the surface of the activated carbon body. .

  In invention of Claim 2, in the invention of Claim 1, the said activated carbon main body is formed in the cylinder shape, and the said thermal storage molded object is accommodated inside the said activated carbon main body.

  In this way, the activated carbon main body is formed in a cylindrical shape, and the heat storage molded body is accommodated therein, thereby obtaining an evaporative fuel adsorber having a simple structure and a structure in which the heat storage member is built in the main body of the activated carbon. .

  In invention of Claim 3, in the invention of Claim 2, the said heat storage molded object is arrange | positioned in the position which entered inside from the axial direction edge part of the said activated carbon main body formed in the cylinder shape.

  In this way, by disposing the heat storage molded body at a position that goes inward from the axial end of the activated carbon main body, the heat storage member is not exposed from the axial end of the activated carbon main body, so that the heat storage member is more easily dropped. Suppressed reliably.

  In invention of Claim 4, in the invention of Claim 1, the said heat storage molded object is covered with the said activated carbon main body the whole outer surface.

  Thus, the fall of a heat storage member is suppressed more reliably by covering the whole surface of the outside of a heat storage molded object with an activated carbon main body.

  The invention according to claim 5 includes the evaporated fuel adsorbent according to any one of claims 1 to 4, wherein the introduced evaporated fuel is adsorbed by the activated carbon main body, and the adsorbed evaporated fuel is absorbed. Desorption from the activated carbon body.

  In this canister, the introduced evaporative fuel gas is adsorbed by the evaporative fuel adsorbent, but the temperature rise at the time of adsorption is suppressed by the heat storage member, and a decrease in the adsorption capacity is prevented. Further, at the time of desorption of the adsorbed evaporated fuel, the temperature decrease is suppressed by the heat storage member, and the decrease of the desorption capability is prevented.

  The evaporative fuel adsorber has an activated carbon main body formed of activated carbon, and a plurality of heat storage members are built in the activated carbon main body. Accordingly, even when the activated carbon main body is rubbed, the heat storage member is prevented from falling off, and the effect of suppressing the temperature change of the activated carbon can be maintained.

  Since the present invention has the above-described configuration, an evaporative fuel adsorber that can suppress the dropout of the heat storage material and a canister including the evaporative fuel adsorber are obtained.

(A) is sectional drawing which shows schematic structure of the canister of 1st Embodiment of this invention, (B) is explanatory drawing which picks up and shows the fuel vapor adsorption body inside this canister. BRIEF DESCRIPTION OF THE DRAWINGS The vaporized fuel adsorption body of 1st Embodiment of this invention is shown, (A) is a perspective view, (B) is sectional drawing cut | disconnected by the plane which passes along a central axis. It is sectional drawing which shows the thermal storage material capsule which comprises the evaporative fuel adsorption body of this invention. The evaporated fuel adsorption body of 2nd Embodiment of this invention is shown, (A) is a perspective view, (B) is sectional drawing cut | disconnected by the plane which passes along a central axis. The evaporated fuel adsorption body of 3rd Embodiment of this invention is shown, (A) is a perspective view, (B) is sectional drawing cut | disconnected by the plane which passes along a central axis. (A) is sectional drawing which shows schematic structure of the canister of 4th Embodiment of this invention, (B) is explanatory drawing which picks up and shows the evaporative fuel adsorption body inside this canister. The evaporative fuel adsorption body of 4th Embodiment of this invention is shown, (A) is a perspective view, (B) is sectional drawing cut | disconnected by the plane which passes along the center.

  FIG. 1A shows a canister 12 according to the first embodiment of the present invention. The canister 12 has a canister body 14 formed in a substantially box shape. Inside the canister main body 14, filter films 16, 18 configured in a substantially plate shape with a nonwoven fabric or the like are provided in parallel to the one end wall 14 </ b> A and the other end wall 14 </ b> B.

  A partition wall 20 that reaches the filter film 18 extends from the one end wall 14 </ b> A of the canister body 14. The partition 20 and the filter films 16 and 18 constitute a first adsorption chamber 22 and a second adsorption chamber 24 in the canister body 14. Then, a substantially U-shaped gas flow path including a direction F1 from the first adsorption chamber 22 through the space 28 between the filter film 18 and the other end wall 14B to the second adsorption chamber 24 and the opposite direction F2. Is configured.

  The canister body 14 is provided with an introduction pipe 32 connected to a fuel tank (not shown) at a position corresponding to the first adsorption chamber 22. Similarly, a discharge pipe 34 connected to an engine (not shown) is provided at a position corresponding to the first adsorption chamber 22. Further, an atmosphere communication pipe 36 communicating with the atmosphere is provided at a position corresponding to the second adsorption chamber 24.

  Evaporated fuel gas is generated in the fuel tank at the time of refueling or the like, and this evaporated fuel gas is introduced into the canister 12 through the introduction pipe 32. Then, the evaporated fuel component of the introduced evaporated fuel gas is adsorbed by the evaporated fuel adsorber 30 described later, and the purified air is released into the atmosphere through the atmosphere communication pipe 36. Further, when the vehicle travels, the evaporated fuel component adsorbed on the evaporated fuel adsorbing body 30 is desorbed and sent to the engine from the exhaust pipe 34 together with the air introduced through the atmospheric communication pipe 36. Yes.

  As shown in FIG. 1B, the first adsorption chamber 22 and the second adsorption chamber 24 are filled with a large number of evaporated fuel adsorbers 30. As shown in detail in FIGS. 2A and 2B, each of the evaporated fuel adsorbers 30 is accommodated (built in) in the activated carbon main body 38 formed in a cylindrical shape in this embodiment. And a columnar heat storage molded body 40. That is, the evaporated fuel adsorbing body 30 is composed of two layers of an outer layer activated carbon main body 38 and an inner layer heat storage molded body 40. In the present embodiment, the axial length L2 of the heat storage molded body 40 is substantially the same as the axial length L1 of the activated carbon main body 38, and the axial end face 38E of the activated carbon main body 38 and the heat storage molded body 40 are. The axial end surface 38E is flush with the surface (at least the heat storage molded body 40 does not protrude from the inside of the activated carbon main body 38).

  The activated carbon main body 38 is formed by kneading activated carbon having an action of adsorbing and desorbing evaporated fuel into a desired shape (cylindrical in the present embodiment). Yes. Therefore, the activated carbon main body 38 adsorbs and desorbs the evaporated fuel particularly on the entire surface thereof.

  The heat storage molded body 40 has a plurality of heat storage material capsules 42. As shown in detail in FIG. 3, the heat storage material capsule 42 is configured by enclosing a phase-change heat storage material 46 inside a spherical shell-shaped microcapsule 44 formed of resin or ceramic. Then, a large number of heat storage material capsules 42 are joined and hardened with a binder to form a microcapsule group 48 in which the heat storage material capsules 42 are integrated as shown in FIGS. 2A and 2B as a whole. The microcapsule group 48 is formed into a shape that can be accommodated inside the activated carbon main body 38, in this embodiment, a columnar shape, and is used as a heat storage molded body 40. The heat storage molded body 40 is in contact with the inner peripheral surface of the activated carbon main body 38 over the entire outer peripheral surface.

  In the present embodiment, as described above, the heat storage molded body 40 is built in the activated carbon main body 38 so that the axial end surface 38E of the activated carbon main body 38 and the axial end surface 38E of the heat storage molded body 40 are flush with each other. ing. Therefore, the axial end surface 38E of the heat storage molded body 40 is exposed from the surface of the activated carbon main body 38, but the other parts (substantially most of the heat storage material capsules 42 constituting the heat storage molded body 40) are the activated carbon main body 38. Not exposed from the surface.

  In addition, as a binder which joins the microcapsule 44, a soft resin can be used, for example. When a soft resin binder is used, a dimensional change between the activated carbon main body 38 and the heat storage molded body 40 can be absorbed by the binder during expansion or contraction due to heat. In this embodiment, in particular, a soft resin having a linear expansion coefficient similar to that of the activated carbon main body 38 is used as the binder, and a deviation or distortion occurs between the activated carbon main body 38 and the heat storage molded body 40 during expansion or contraction. There is no such thing.

  The evaporated fuel adsorber 30 having such a structure is filled in the first adsorption chamber 22 and the second adsorption chamber 24 of the canister main body 14 as shown in FIG. A coil spring 26 is disposed in the space 28 between the filter film 18 and the other end wall 14B, and the filter film 16 is urged in a direction to reduce the volume of the first adsorption chamber 22 and the second adsorption chamber 24. Yes. As a result, the evaporated fuel adsorber 30 is also maintained at a predetermined filling density.

  Next, the operation of this embodiment will be described.

  In the canister 12 of this embodiment, as shown by an arrow F1 in FIG. 1A, the evaporated fuel component of the evaporated fuel gas introduced through the introduction pipe 32 at the time of refueling or the like is adsorbed by the evaporated fuel adsorber 30. The purified air is released to the atmosphere via the atmosphere communication pipe 36. Further, as shown by an arrow F2 in FIG. 1A, when the vehicle travels, the evaporated fuel component adsorbed by the evaporated fuel adsorbent 30 is desorbed and together with the air introduced through the atmospheric communication pipe 36. The exhaust pipe 34 is sent to the engine.

  Here, in general, in the evaporated fuel adsorbent 30 including activated carbon, the temperature of the activated carbon main body 38 is increased when the evaporated fuel gas is adsorbed, and the adsorption capacity is decreased. Ability is reduced. In the present embodiment, the evaporative fuel adsorbing body 30 incorporates the heat storage molded body 40, so that heat is transferred from the activated carbon main body 38 to the heat storage molded body 40 during the adsorption of the evaporated fuel, and the temperature rise of the activated carbon main body 38 is suppressed. The Further, at the time of desorption, heat is transferred from the heat storage molded body 40 to the activated carbon main body 38, and the temperature decrease of the activated carbon main body 38 is suppressed (hereinafter, the temperature increase suppressing effect during adsorption and the temperature decrease suppressing effect during desorption are summarized. Is called warming effect). Thereby, the performance fall accompanying the temperature change of the evaporative fuel adsorption body 30 is prevented.

  In particular, in this embodiment, each of the evaporated fuel adsorbers 30 includes a heat storage molded body 40. Therefore, in both the first adsorption chamber 22 and the second adsorption chamber 24, the heat retention effect by the heat storage molded body 40 acts equally on the activated carbon main body 38, and the adsorption performance and desorption performance of the activated carbon main body 38 are maintained. The

  And in this embodiment, it is set as the structure where the thermal storage molded object 40 contacts the inner peripheral surface of the activated carbon main body 38 over the whole outer peripheral surface. Since a wide contact area between the heat storage molded body 40 and the activated carbon main body 38 can be ensured, heat can be efficiently transferred between the heat storage molded body 40 and the activated carbon main body 38.

  Further, in the evaporated fuel adsorbing body 30 of the present embodiment, the heat storage molded body 40 is built in the activated carbon main body 38, and the inner layer side heat storage molded body 40 is substantially protected by the outer layer side activated carbon main body 38. ing. Inside the first adsorption chamber 22 and the second adsorption chamber 24, the vaporized fuel adsorbers 30 may come into contact with each other and wear. Therefore, for example, the heat storage material capsule 42 constituting the heat storage molded body 40 is adsorbed by the vaporized fuel. If many are exposed on the surface of the body 30, the exposed heat storage material capsules 42 may fall off the evaporated fuel adsorbent 30 due to wear. However, in this embodiment, since the heat storage molded body 40 (heat storage material capsule 42) is accommodated in the activated carbon main body 38, dropping of the heat storage material capsule 42 is suppressed. Is also suppressed. Thereby, the adsorption performance and desorption performance of the evaporated fuel adsorbent 30 are also stabilized.

  In addition, a large number of heat storage material capsules 42 encapsulating the heat storage material 46 are joined and hardened with a binder to form an integrated heat storage molded body 40, and the heat storage molded body 40 is accommodated inside the activated carbon main body 38. is doing. Accordingly, the structure in which the plurality of heat storage material capsules 42 are dispersed (not integrated) in the activated carbon main body 38 can more effectively suppress the dropout of the heat storage material capsules 42.

  In addition, although the manufacturing method of the fuel vapor adsorbent 30 of 1st Embodiment is not specifically limited, For example, activated carbon is the state which hold | maintained the heat storage molded object 40 of the elongate (long cylindrical rod shape) inside (center). The evaporative fuel adsorbent 30 is obtained by extruding the kneaded activated carbon main body 38 into a long shape and cutting it into a predetermined length (collecting the heat storage molded body 40 and the activated carbon main body 38 together).

  4A and 4B show an evaporated fuel adsorbent 60 according to a second embodiment of the present invention. In each of the following embodiments, only the structure of the evaporated fuel adsorber is different from that of the first embodiment, and the same constituent elements as those of the first embodiment are denoted by the same reference numerals and appropriately described. Is omitted. In the second and subsequent embodiments, the overall configuration of the canister is substantially the same as that of the first embodiment.

  In the evaporated fuel adsorbing body 60 of the second embodiment, the cylindrical activated carbon main body 38 includes a columnar heat storage member 62, but the axial length L <b> 2 of the thermal storage member 62 is the axial direction of the activated carbon main body 38. The axial end face 62E of the heat storage member 62 is positioned axially inward from the axial end face 38E of the activated carbon main body 38. In other words, the cavity 64 is formed inside the activated carbon main body 38 at both axial ends of the heat storage molded body 40.

  As described above, the evaporated fuel adsorber 60 of the second embodiment has a structure in which the heat storage molded body 40 enters the inner side in the axial direction with respect to the activated carbon main body 38, so that it is compared with the evaporated fuel adsorber 30 of the first embodiment. Thus, the possibility of wear of the axial end surface 62E of the heat storage member 62 is further reduced. That is, the dropout of the heat storage member 62 (heat storage material capsule 42) can be further suppressed than in the first embodiment.

  The evaporative fuel adsorber 60 of the second embodiment can be manufactured in substantially the same manufacturing direction as the evaporative fuel adsorber 30 of the first embodiment, but the heat storage member 62 has a length L2 as a finished product in advance. After cutting the heat storage member 62 in a predetermined direction with a one-point interval, the activated carbon main body 38 is pushed out into a long shape, and then the activated carbon main body 38 is cut at an intermediate portion of the heat storage member 62. do it. However, in the evaporative fuel adsorbing body 60 of the second embodiment, it may be difficult to specify the position at which the elongated activated carbon main body is cut (it is necessary to prevent deviation from the intermediate portion of the heat storage member 62). In this respect, the evaporative fuel adsorber 30 of the first embodiment is easier to manufacture.

  FIGS. 5A and 5B show an evaporated fuel adsorbent 70 according to a third embodiment of the present invention. In the evaporated fuel adsorbing body 70 according to the third embodiment, the axial length L2 of the heat storage member 62 is shorter than the axial length L1 of the activated carbon main body 38 in the same manner as in the second embodiment. In the second embodiment, the portion that has become the hollow portion 64 is also in the shape of the activated carbon main body 72 in which the activated carbon is disposed.

  Therefore, in the third embodiment, the surface (surrounding) of the heat storage member 62 is completely covered with the activated carbon main body 72. For this reason, the dropout of the heat storage member 62 (heat storage material capsule 42) can be further suppressed than in the second embodiment.

  The method for manufacturing the evaporated fuel adsorbent 70 according to the third embodiment is not particularly limited. For example, the evaporated fuel adsorbent 60 according to the second embodiment is once manufactured, and activated carbon is further added to the cavity 64. It may be filled. Alternatively, the columnar heat storage member 62 (length L2) may be formed first, and activated carbon may be coated around it to form the columnar evaporated fuel adsorbent 70 as a whole.

  FIG. 6A shows a canister 92 provided with an evaporated fuel adsorbent 80 according to a fourth embodiment of the present invention. FIGS. 6B and 7 show an evaporated fuel adsorbent 80 according to the fourth embodiment. In the evaporated fuel adsorbing body 80 of the fourth embodiment, the overall shape is substantially spherical, and the heat storage member 84 is joined so that a large number of heat storage material capsules 42 are generally spherical. That is, in the evaporated fuel adsorbent 80 of the fourth embodiment, the activated carbon main body 82 having a substantially constant thickness is coated around the substantially spherical heat storage member 84. 6A, the evaporative fuel adsorber 80 is filled in the first adsorption chamber 22 and the second adsorption chamber 24 of the canister main body 14, whereby the canister 92 of the fourth embodiment is configured. ing.

  Therefore, also in the evaporated fuel adsorbent 80 of the fourth embodiment, the surface (periphery) of the heat storage member 84 is completely covered with the activated carbon main body 82 as in the evaporated fuel adsorbent 70 of the third embodiment. For this reason, the dropout of the heat storage member 84 (heat storage material capsule 42) can be further suppressed than in the second embodiment.

  The manufacturing method of the evaporated fuel adsorbent 80 according to the fourth embodiment is not particularly limited. For example, the heat storage material capsule 42 is first joined with a binder or the like to form a substantially spherical heat storage member 84, and the periphery of the heat storage member 84. The activated carbon main body 82 may be configured by coating activated carbon with a substantially constant thickness (while rotating the heat storage member 84 as necessary).

  In each of the above embodiments, the heat storage member of the present invention is configured by a substantially spherical heat storage material capsule 42. However, the shape of the heat storage material capsule 42 is not limited to a spherical shape, and other shapes may be used. Good. However, if the shape is substantially spherical, the pressure resistance against the change in the internal pressure of the heat storage material capsule 42 due to the temperature change of the heat storage material 46 can be ensured higher than other shapes.

  In addition, the shape of the heat storage member (microcapsule group 48) is also exemplified as a cylindrical shape and a substantially spherical shape in the above, but is not limited thereto. If the heat storage member has a columnar shape as in the first to third embodiments, the activated carbon main body 38 can be widely and uniformly contacted, so that the adsorption performance and desorption performance of the activated carbon main body 38 can be improved. . Moreover, even if the heat storage member has a substantially spherical shape as in the fourth embodiment, the activated carbon main body 38 can be brought into uniform contact with the activated carbon main body 38, so that the adsorption performance and desorption performance of the activated carbon main body 38 can be improved.

12 canister 14 canister body 16 filter film 18 filter film 22 first adsorption chamber 24 second adsorption chamber 30 evaporated fuel adsorber 38 activated carbon main body 40 heat storage molded body 42 heat storage material capsule (heat storage member)
44 Microcapsule 46 Heat storage material 48 Microcapsule group 60 Evaporated fuel adsorber 62 Heat storage member 64 Cavity 70 Evaporated fuel adsorber 72 Activated carbon main body 80 Evaporated fuel adsorbent 82 Activated carbon main body 84 Thermal storage member

Claims (5)

An activated carbon body formed of activated carbon that performs adsorption and desorption of evaporated fuel;
A plurality of heat storage members that suppress the temperature change of the activated carbon main body are integrated, and a heat storage molded body built in the activated carbon main body,
An evaporative fuel adsorber having The activated carbon body is formed in a cylindrical shape,
The evaporated fuel adsorbent according to claim 1, wherein the heat storage molded body is accommodated inside the activated carbon main body.   The evaporated fuel adsorbent according to claim 2, wherein the heat storage molded body is disposed at a position entering the inside from an axial end of the activated carbon main body formed in a cylindrical shape.   The evaporated fuel adsorbent according to claim 1, wherein the heat storage molded body is entirely covered with the activated carbon main body. The fuel vapor adsorbent according to any one of claims 1 to 4, comprising:
A canister that adsorbs the introduced evaporated fuel by the activated carbon main body and desorbs the adsorbed evaporated fuel from the activated carbon main body.

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