JP2009215938A - Evaporated fuel treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a closed vessel capable of absorbing volume increase of thermal storage medium with a simple structure. <P>SOLUTION: This evaporated fuel treatment device is provided with a canister filled with adsorbent capable of adsorbing evaporated fuel in a fuel tank, and the thermal storage medium 17 inhibiting temperature change of an inside of the canister with using latent heat of coagulation and dissolution. The heat storage medium 17 is installed in the canister under a condition that the same is stored in the closed vessel 40. A space S capable of absorbing volume increase of the thermal storage medium 17 is provided between an inner wall surface of the closed vessel 40 and a surface of the thermal storage medium 17 in the closed vessel 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a canister filled with an adsorbent capable of adsorbing evaporated fuel in a fuel tank, and a heat storage material that suppresses temperature change in the canister using latent heat when solidifying or melting. The present invention relates to a fuel vapor processing apparatus.

A conventional evaporative fuel processing apparatus related to this is described in Patent Document 1.
In this fuel vapor processing apparatus, a latent heat storage material (a heat storage material that uses latent heat when solidifying or melting) that suppresses temperature changes in the canister is installed in the canister in a state of being housed in an airtight container.

US005861050A

  Since the latent heat storage material generally expands when it absorbs and melts heat, the sealed container needs a mechanism for absorbing the volume increase of the latent heat storage material. However, the mechanism for absorbing the volume increase of the latent heat storage material is not clear in the above evaporative fuel processing apparatus.

  The present invention has been made to solve the above problems, and a technical problem of the present invention is to be able to manufacture a sealed container capable of absorbing the volume increase of the heat storage material with a simple configuration. .

The above-described problems are solved by the inventions of the claims.
The invention according to claim 1 is a canister filled with an adsorbent capable of adsorbing evaporated fuel in a fuel tank, and a heat storage material that suppresses temperature change in the canister by using latent heat when solidifying or melting. The heat storage material is installed in the canister in a state of being housed in a sealed container, and the space in which the volume increase of the heat storage material can be absorbed in the sealed container Is provided between the inner wall surface of the sealed container and the surface of the heat storage material.

  According to this invention, the space which can absorb the volume increase of a thermal storage material is provided in the airtight container between the inner wall surface of the airtight container, and the surface of the said thermal storage material. For this reason, for example, even when the heat storage material melts from a solid state and becomes a liquid, the volume increases, the increase in volume is absorbed by the compressed gas in the space, and the sealed container is impossible. The power is not added.

According to invention of Claim 2, the unevenness | corrugation is formed in the outer wall surface of an airtight container, It is characterized by the above-mentioned.
For this reason, the heat exchange property between the heat storage material and the adsorbent of the canister is improved.
According to invention of Claim 3, the unevenness | corrugation is formed in the inner wall face of an airtight container, It is characterized by the above-mentioned.
For this reason, even if the sealed container is inclined when the heat storage material is in a liquid phase, the internal heat storage material is less likely to concentrate on one end side of the sealed container.
According to the invention of claim 4, the sealed container is formed flat by joining the peripheral part of the lid-like upper panel and the peripheral part of the lower panel formed in a shallow open container shape to each other. The surface of the lower panel is set to be larger than the surface area of the upper panel.
Thus, since the surface area of the lower panel which accumulates when the heat storage material is in a liquid phase state is larger than the surface area of the upper panel, heat exchange can be enhanced.

According to the invention of claim 5, the space of the sealed container is filled with an inert gas.
For this reason, deterioration of the heat storage material can be prevented. Further, the sealed state of the sealed container can be checked by performing an inert gas leak test.
According to a sixth aspect of the present invention, the plurality of sealed containers are attached to the canister in a state where they are stacked at intervals in the vertical direction.
That is, since the lower panel of the upper sealed container is disposed above the upper panel of the sealed container disposed in the lower stage, the adsorbent for the canister is the upper panel of the lower sealed container and the lower panel of the upper sealed container. Sandwiched between them. For this reason, even if the heat exchange effect differs between the upper panel and the lower panel, the adsorbent of the canister can exchange heat with the heat storage material substantially evenly.

  According to the present invention, an increase in the volume of the heat storage material can be absorbed with a simple configuration, and therefore an unreasonable force is not applied to the sealed container that stores the heat storage material.

(Embodiment 1)
Hereinafter, the evaporated fuel processing apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 5. The evaporative fuel processing apparatus according to the present embodiment is an apparatus mounted on a vehicle such as an automobile. FIG. 1 is an overall configuration diagram of a canister used in the evaporative fuel processing apparatus according to the present embodiment (plan view from below). It is shown. 2 is a cross-sectional view taken along the line II-II in FIG. 3 and 4 are a plan view and a sectional view of the main sealed container, and FIG. 5 is a plan view and a sectional view of the auxiliary sealed container.

<About the Evaporative Fuel Treatment System>
The evaporative fuel processing apparatus is an apparatus for preventing evaporative fuel generated in a fuel tank (not shown) from leaking into the atmosphere, and a canister 20 filled with an adsorbent 12 that adsorbs the evaporative fuel, and the canister 20 and an evaporative fuel passage (not shown) for communicating the fuel tank, a purge passage (not shown) for communicating the canister 20 and the intake passage of the engine, and the like.
In the evaporated fuel processing apparatus, while the engine is stopped, the evaporated fuel in the fuel tank is guided into the canister 20 through the evaporated fuel passage, and the evaporated fuel is adsorbed by the adsorbent 12. Further, during the operation of the engine, the evaporated fuel adsorbed on the adsorbent 12 is purged by the air that flows from the outside into the canister 20 and flows into the intake passage of the engine via the purge passage. In other words, the evaporated fuel adsorbed by the adsorbent 12 of the canister 20 is purged from the adsorbent 12 by being purged with external air, and supplied to the intake passage of the engine. With the above configuration, it is possible to prevent the evaporated fuel generated in the fuel tank from flowing out to the atmosphere.

<About the canister 20>
As shown in FIGS. 1 and 2, the canister 20 includes a container body 21 that is partitioned into a plurality of parts, and a lid 22 that closes an opening (the lower end side in FIG. 1) of the container body 21. ing. As shown in FIG. 2, the inside of the container main body 21 is partitioned by a partition wall 21w into a main chamber 24 having a substantially rectangular cross section and a sub chamber 25 having a substantially circular cross section. The sub chamber 25 is partitioned into a first sub chamber 25a and a second sub chamber 25b by a buffer plate 23 as shown in FIG.
In the container main body 21, a tank port 241, a purge port 242, and an atmospheric port 251 are formed side by side on the bottom wall portion opposite to the lid portion 22. The atmospheric port 251 communicates with the first sub chamber 25a through a perforated plate 25x having a large number of fine openings. The tank port 241 and the purge port 242 communicate with the main chamber 24 through a perforated plate 24x having a large number of fine openings. A partition wall 24k is formed on the bottom wall portion of the container body 21 on the main chamber 24 side so as to protrude into the main chamber 24, and the inner space of the main chamber 24 communicating with the tank port 241 by the partition wall 24k. And the internal space of the main chamber 24 communicating with the purge port 242 are separated.

In the main chamber 24 of the container main body 21, a plurality of (for example, three) main sealed containers 40 containing a heat storage material 17 to be described later are provided as shown in FIG. 2 with the lid 22 open. It can be installed with a space in the vertical direction. The adsorbent 12 is filled in the space between the main sealed containers 40 and the space between the main sealed container 40 and the inner wall surface of the main chamber 24.
The adsorbent 12 is made of activated carbon or the like that adsorbs the evaporated fuel and is capable of releasing the adsorbed evaporated fuel by air purging. Here, the opening of the porous plate 24x is set to a size sufficiently smaller than the adsorbent 12, and is configured so that the adsorbent 12 can be held in the main chamber 24.
As shown in FIG. 1, the opening of the main chamber 24 of the container main body 21 is closed by the inner lid plate 27 after the completion of the attachment of the main sealed container 40 and the filling of the adsorbent 12. The inner lid plate 27 is a breathable lid plate composed of the first filter 27 f and the porous plate 27 x and functions to hold the adsorbent 12 in the main chamber 24. The inner lid plate 27 is configured to be slidable along the inner wall surface of the main chamber 24 in a state where the opening of the main chamber 24 is closed. One end of a coil spring 27s biased in the direction of pressing the inner lid plate 27 is attached to the center of the back surface of the inner lid plate 27. For this reason, when the opening of the container body 21 is closed by the lid 22, the other end of the coil spring 27 s is pressed by the inner wall surface of the lid 22. Thereby, the inner lid plate 27 receives a force in a direction to be pushed into the main chamber 24 by the coil spring 27s. As a result, an unnecessary space is not formed between the particles of the adsorbent 12, and the ventilation resistance can be made substantially constant.

As described above, the sub chamber 25 of the container body 21 is divided into the first sub chamber 25a and the second sub chamber 25b by the buffer plate 23. As shown in FIG. A second filter 23f is mounted on the second sub chamber 25b side.
In the second sub chamber 25b of the container main body 21, a plurality of (for example, two) auxiliary sealed containers 50 containing the heat storage material 17 are provided as shown in FIG. It can be installed with a space in the vertical direction. Then, the adsorbent 12 is filled into the space between the auxiliary sealed containers 50 and between the auxiliary sealed container 50 and the inner wall surface of the second sub chamber 25b.
Further, the opening of the second sub chamber 25b is closed by the inner lid plate 29 as shown in FIG. 1 after the auxiliary sealed container 50 is completely attached and the adsorbent 12 is filled. The inner lid plate 29 is a breathable lid plate composed of the third filter 29f and the porous plate 29x, and functions to hold the adsorbent 12 in the second sub chamber 25b.
The inner lid plate 29 is configured to be slidable along the inner wall surface of the second sub chamber 25b in a state where the opening of the second sub chamber 25b is closed. One end of a coil spring 29s biased in the direction of pressing the inner lid plate 29 is attached to the center of the back surface of the inner lid plate 29. For this reason, when the opening of the container main body 21 is closed by the lid portion 22, the inner lid plate 29 receives a force in a direction to be pushed into the second sub chamber 25b by the coil spring 29s.
Here, the space 26 formed by the inner lid plate 29 that closes the second sub chamber 25b and the inner lid plate 27 that closes the main chamber 24 and the lid portion 22 is the main chamber 24 and the second sub chamber 25b. It functions as a diffusion space 26 that communicates with each other.

<Regarding the heat storage material 17, the main sealed container 40, and the auxiliary sealed container 50>
The heat storage material 17 is a member that suppresses a temperature change in the canister 20 by using latent heat at the time of solidification or melting. In the present embodiment, for example, hexadecane (C ₁₆ H ₃₄ ) having a melting point of 18 ° C. is used. For this reason, when the temperature in the canister 20 rises and exceeds 18 ° C., the heat in the canister 20 is taken away when the heat storage material 17 melts, thereby suppressing the temperature rise in the canister 20. Conversely, when the temperature in the canister 20 decreases to 18 ° C. or less, heat is released when the heat storage material 17 solidifies, and the temperature decrease in the canister 20 can be suppressed.
The main sealed container 40 is a container for storing the heat storage material 17, and as shown in FIGS. 3A, 3B and 4, the flange portion 42e of the upper panel 42 formed in a lid shape and a shallow open container. It is comprised by joining the flange part 44e of the lower panel 44 formed in the shape. As shown in FIG. 3A, the upper panel 42 is formed in a rectangular shape by, for example, a stainless steel plate, and a peripheral portion thereof becomes a flange portion 42e having a constant width. In the upper panel 42, grooves 42m and ridges 42p having a square cross section and extending in the longitudinal direction of the upper panel 42 are alternately formed with a constant width within a range surrounded by the flange 42e. Here, since the upper panel 42 is configured by press-molding a stainless steel plate, the portion that becomes the protruding portion 42p on the front surface side of the upper panel 42 becomes a groove portion on the back surface side, and the groove portion 42m on the front surface side. The part which becomes becomes a protrusion part on the back side.

As shown in FIGS. 3B and 4, the lower panel 44 is formed in a rectangular shallow box shape, for example, by a stainless steel plate, and a peripheral portion thereof becomes a flange portion 44 e having a constant width. Then, in the bottom plate portion of the lower panel 44, grooves 44m and ridges 44p having a square cross section and extending in the longitudinal direction of the lower panel 44 are alternately formed with a constant width. Since the lower panel 44 is configured by press-molding a stainless steel plate in the same manner as the upper panel 42, the ridge portion is formed on the lower surface side of the lower panel 44 (see FIG. 4, the outer surface side of the main hermetic container 40). The part which becomes 44p becomes a groove part on the upper surface side (the inner surface side of the main sealed container 40), and the part which becomes the groove part 44m on the lower surface side becomes a ridge part on the upper surface side.
The width dimension and length dimension of the lower panel 44 are set to the same value as the width dimension and length dimension of the upper panel 42, and the width dimension of the groove 44m and the protrusion 44p of the lower panel 44 is the upper dimension. It is set to a value equal to the width dimension of the groove 42m and the protrusion 42p of the panel 42.
That is, the flange portion 42e of the upper panel 42 and the flange portion 44e of the lower panel 44 correspond to the peripheral portion of the present invention, and the groove portion 42m and the protrusion portion 42p of the upper panel 42, and the groove portion 44m and the protrusion portion of the lower panel 44. The portion 44p corresponds to the unevenness of the present invention.

As shown in FIG. 3B, the flange portion 44e of the lower panel 44 and the flange portion 42e of the upper panel 42 are joined by laser welding or the like in a state where the heat storage material 17 is stored in the main hermetic container 40. The space S is filled with helium gas.
As shown in FIG. 2, the main airtight container 40 is a set in which flange portions 42 e and 44 e formed on both sides in the width direction of the main airtight container 40 are formed on both sides in the inner wall surface width direction of the main chamber 24 of the canister 20. Is fitted into the rail-shaped groove 245. Thereby, the main hermetic container 40 is attached in the main chamber 24 in a substantially horizontal state. Here, three sets of rail-shaped groove portions 245 are formed on the inner wall surface of the main chamber 24, and the upper, middle, and lower rail-shaped groove portions 245 are formed at equal intervals in the height direction.

The auxiliary sealed container 50 is a container that stores the heat storage material 17 in the same manner as the main sealed container 40. The auxiliary sealed container 50 has the same configuration as the main sealed container 40 and is smaller than the main sealed container 40 as shown in FIG. Is formed. For this reason, about the same component as the main airtight container 40, the same code | symbol is attached | subjected and description is abbreviate | omitted.
As shown in FIG. 2, the auxiliary sealed container 50 has an inner wall surface of the buffer plate 23 in which flange portions 42 e and 44 e formed on both sides in the width direction of the auxiliary sealed container 50 are located in the second sub chamber 25 b of the canister 20. It fits into a set of rail-shaped groove portions 255 formed on both sides in the width direction. Thereby, the auxiliary sealed container 50 is attached in a substantially horizontal state in the second sub chamber 25b. Here, two sets of rail-shaped groove portions 255 are formed on the inner wall surface of the buffer plate 23 in the second sub chamber 25b, and the upper and lower rail-shaped groove portions 245 are formed at predetermined intervals in the height direction. Yes.

<Operation of Evaporative Fuel Treatment Device>
First, the operation of the evaporated fuel processing device when the engine is stopped will be described.
The evaporated fuel generated in the fuel tank is guided into the main chamber 24 from the tank port 241 of the canister 20 through the evaporated fuel passage and is adsorbed by the adsorbent 12 in the main chamber 24 as shown by the white arrow in FIG. Is done. Then, the evaporated fuel that could not be adsorbed by the adsorbent 12 in the main chamber 24 is guided to the second sub chamber 25 b through the diffusion space 26. When evaporated fuel is adsorbed on the adsorbent 12, the temperature of the adsorbent 12 rises and the adsorption efficiency gradually decreases. However, since the heat storage material 17 is accommodated in the canister 20 via the main sealed container 40 and the auxiliary sealed container 50, when the temperature in the canister 20 rises and exceeds 18 ° C., the heat storage material 17 When melting, the heat in the canister 20 can be removed, and the temperature rise in the canister 20 can be suppressed. For this reason, a decrease in the adsorption efficiency of the evaporated fuel of the adsorbent 12 can be suppressed.
Here, when the heat storage material 17 melts, the volume of the heat storage material 17 increases. However, since the space S is provided inside the main sealed container 40 and the auxiliary sealed container 50, the volume of the heat storage material 17 increases. The portion is absorbed by the compressed portion of the helium gas in the space S, and an excessive force is not applied to the main sealed container 40 and the auxiliary sealed container 50.

During operation of the engine, negative pressure in the intake passage is applied to the main chamber 24, the diffusion space 26, the second sub chamber 25b, and the first sub chamber 25a of the canister 20 through the purge passage through the purge port 242. As a result, as shown by the thick arrows in FIG. 1, air flows from the atmospheric port 251 into the first sub chamber 25a of the canister 20, and the air passes through the second sub chamber 25b, the diffusion space 26, and the main chamber 24, It flows to the intake passage through the purge port 242 and the purge passage. Thereby, the evaporated fuel adsorbed on the adsorbent 12 of the canister 20 is purged, and the purged evaporated fuel is guided into the intake passage together with air.
When the evaporated fuel adsorbed on the adsorbent 12 is purged and the evaporated fuel is desorbed from the adsorbent 12, the temperature of the adsorbent 12 is lowered and the evaporative fuel desorption efficiency is gradually decreased. However, when the temperature in the canister 20 decreases to 18 ° C. or less, heat is released when the heat storage material 17 is solidified, and the temperature decrease in the canister 20 is suppressed. For this reason, it is possible to suppress a decrease in the evaporative fuel removal efficiency of the adsorbent 12.

<Advantages of evaporative fuel treatment equipment>
According to the fuel vapor processing apparatus according to the present embodiment, the space S that can absorb the increased volume of the heat storage material 17 is formed in the sealed containers 40 and 50 between the inner wall surface of the sealed containers 40 and 50 and the surface of the heat storage material 17. It is provided in between. For this reason, for example, even when the heat storage material 17 is melted from a solid state to become a liquid and the volume increases, the volume increase is absorbed by the compressed gas in the space S, and the sealed container 40, Unreasonable power is not added to 50.
Moreover, since the groove part 44m and the protrusion part 44p are formed in the outer wall surface of the airtight containers 40 and 50, the heat exchange property between the heat storage material 17 and the adsorbent 12 of the canister 20 improves.
Moreover, since the groove part 44m and the protrusion part 44p are formed also in the inner wall surface of the airtight containers 40 and 50, even if the airtight container 40 and 50 incline when the thermal storage material 17 is a liquid phase state, It becomes difficult for the heat storage material 17 to concentrate on one end side of the sealed containers 40 and 50.

Further, the sealed containers 40 and 50 are formed flat and attached to the canister 20 almost horizontally, and the surface area of the lower panel 44 is set larger than the surface area of the upper panel 42. As described above, since the surface area of the lower panel 44 accumulated when the heat storage material 17 is in the liquid phase state is larger than the surface area of the upper panel 42, the heat exchange property can be increased.
Further, since the space S of the sealed containers 40 and 50 is filled with an inert gas such as helium gas, the heat storage material 17 can be prevented from being deteriorated. Moreover, the sealed state of the airtight containers 40 and 50 can be inspected by inspecting the leakage of the inert gas.
Further, since the adsorbent 12 of the canister 20 is sandwiched between the upper panel 42 of the lower sealed containers 40, 50 and the lower panel 44 of the upper sealed containers 40, 50, the upper panel 42 and the lower panel 44 generate heat. Even if the exchange effects are different, the adsorbent 12 can exchange heat with the heat storage material 17 almost equally.

<Example of change>
The present invention is not limited to the above-described embodiment, and modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, an example in which hexadecane having a melting point of 18 ° C. is used as the heat storage material 17, but the material of the heat storage material can be changed according to the control temperature in the canister 20. For example, heptadecane (C ₁₇ H ₃₆ ) having a melting point of 22 ° C. can be used.
Moreover, although the example which comprises the unevenness | corrugation of the airtight containers 40 and 50 by the groove part 44m of the square cross section and the protrusion part 44p was shown, it is also possible to form the said unevenness | corrugation in a protrusion and a hollow shape. It is also possible to provide fins or the like on the surfaces of the sealed containers 40 and 50.
Moreover, although the example which forms the airtight containers 40 and 50 in a flat box shape was shown, the shape of the airtight containers 40 and 50 can be changed suitably.
Moreover, although the example which uses helium gas as an inert gas with which it fills in the airtight containers 40 and 50 was shown, argon gas, nitrogen, etc. can also be used instead of helium gas.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram (downward plan view) of the canister used with the evaporative fuel processing apparatus which concerns on Embodiment 1 of this invention. It is the II-II arrow sectional drawing of FIG. It is the top view (A figure) seen from the upper direction of the main airtight container, and sectional drawing (B figure). It is the top view seen from the lower part of the main airtight container. It is the top view (A figure) seen from the upper direction of an auxiliary | assistant airtight container, sectional drawing (B figure), and the top view (C figure) seen from the downward direction.

Explanation of symbols

12 ... Adsorbent 17 ... Thermal storage material 20 ... Canister 40 ... Main airtight container 42 ... Upper panel 42m ... Groove (unevenness)
42p ..Ridge (unevenness)
42e ・ ・ Flange part (peripheral part)
44 ... Lower panel 44e..Flange (periphery)
50 ... auxiliary sealed container S ... space

Claims (6)

An evaporative fuel processing apparatus comprising: a canister filled with an adsorbent capable of adsorbing evaporated fuel in a fuel tank; and a heat storage material that suppresses temperature change in the canister by using latent heat when solidifying or melting. Because
The heat storage material is installed in the canister in a state of being stored in a sealed container,
An evaporative fuel processing apparatus, wherein a space capable of absorbing the increased volume of the heat storage material is provided in the sealed container between the inner wall surface of the sealed container and the surface of the heat storage material. It is an evaporative fuel processing apparatus of Claim 1, Comprising:
The evaporative fuel processing apparatus is characterized in that irregularities are formed on an outer wall surface of the sealed container. An evaporative fuel processing apparatus according to claim 1 or 2,
The evaporative fuel processing apparatus is characterized in that irregularities are formed on an inner wall surface of the sealed container. It is an evaporative fuel processing apparatus in any one of Claims 1-3, Comprising:
The airtight container is formed flat by joining the peripheral edge of the lid-shaped upper panel and the peripheral edge of the lower panel formed in a shallow open container shape, and is substantially horizontal to the canister. The evaporative fuel processing apparatus is characterized in that the surface area of the lower panel is set larger than the surface area of the upper panel. An evaporative fuel processing apparatus according to any one of claims 1 to 4,
An evaporative fuel processing apparatus, wherein the space of the sealed container is filled with an inert gas. An evaporative fuel processing apparatus according to any one of claims 4 and 5,
An evaporative fuel processing apparatus, wherein a plurality of the sealed containers are attached in the canister in a state where they are stacked in the vertical direction at intervals.

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