JP2007239641A - Canister - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a canister capable of improving performance and simplifying a configuration simultaneously. <P>SOLUTION: This canister 30 is provided with a flow-in port 32 for evaporation fuel, a canister case 31 forming a flow-out port 33 for evaporation fuel and an atmospheric air port 34 opened for the atmospheric air, a partitioning part 60 forming a suction chamber 35 on a flow-in port 32 side and a flow-out port 33 side and an atmospheric air chamber 36 on an atmospheric air port 34 side by partitioning the inside of the canister case 31 so as to communicate them mutually and having a Peltier element 61 for moving heat from either of the suction chamber 35 and the atmospheric air chamber 36 to the other of them by carrying current, and an adsorbent 70 filled into both of the suction chamber 35 and the atmospheric air chamber 36. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a canister.

2. Description of the Related Art Conventionally, a canister that includes an adsorbent that removably adsorbs evaporated fuel in a canister case in order to suppress the outflow of evaporated fuel generated in a fuel tank to the atmosphere is known.
For example, in the canister disclosed in Patent Document 1, the adsorption chamber on the side of the port through which evaporated fuel flows in and out and the atmospheric chamber on the side of the atmospheric port opened to the atmosphere are formed in the canister case in an interconnected state. Two chambers are filled with adsorbent. The canister is provided with a Peltier element in order to adjust the temperature of the adsorbent in the two chambers and improve the desorption performance of the evaporated fuel.

JP 2003-314384 A

However, in the canister disclosed in Patent Document 1, a Peltier element for adjusting the adsorbent temperature in the adsorption chamber and a Peltier element for adjusting the adsorbent temperature in the atmospheric chamber are provided separately. For this reason, the number of parts constituting the canister increases and the configuration of the canister becomes complicated.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a canister that achieves both improved performance and simplified configuration.

According to the first aspect of the present invention, by partitioning the inside of the canister case, the partition portion that forms the suction chamber on the inflow port and outflow port side and the air chamber on the air port side in an interconnected state is Has a Peltier element that moves heat from one of the adsorption chamber and the atmospheric chamber to the other. As a result, the adsorbent temperature in the adsorption chamber and the adsorbent temperature in the atmospheric chamber can be adjusted by a common Peltier element to form a temperature difference between the two chambers. Fuel adsorption performance and desorption performance can be improved.
According to the second aspect of the present invention, the partition portion has a plurality of Peltier elements stacked in the direction in which the adsorption chamber and the atmospheric chamber are aligned. The effect of improving the adsorption performance and desorption performance can be enhanced.

  According to the third aspect of the present invention, the control means switches at least one of the inflow port and the outflow port by switching the energization polarity to the Peltier element to the first polarity for transferring heat from the atmospheric chamber to the adsorption chamber. The evaporated fuel is easily adsorbed to or desorbed from the adsorbent in the adsorption chamber according to the pressure acting on the canister case. In addition, the control means switches the polarity of energization to the Peltier element to the second polarity for transferring heat from the adsorption chamber to the atmospheric chamber, so that a temperature gradient that becomes lower from the atmospheric chamber side toward the adsorption chamber side. The gas flow toward the outflow port on the adsorption chamber side can be generated.

  According to the fourth aspect of the present invention, in the desorption period in which the evaporated fuel is desorbed from the adsorbent and flows out of the canister case from the outflow port, the control means first sets the energization polarity to the Peltier element to the second. Switch to polarity. As a result, a gas flow toward the outflow port on the adsorption chamber side is generated, so that not only can the evaporated fuel desorbed from the adsorbent be guided to the outflow port on the adsorption chamber side, but also the desorbed fuel. Can be prevented from flowing out into the atmosphere from the atmosphere port side. After this, since the control means switches the energization polarity to the Peltier element to the first polarity, the evaporation that desorbs from the adsorbent in the adsorption chamber by the pressure acting in the canister case from at least one of the inflow port and the outflow port. The amount of fuel can be increased.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.
(First embodiment)
FIG. 2 shows an evaporative fuel processing apparatus to which the canister according to the first embodiment of the present invention is applied. The evaporative fuel processing device 10 processes evaporative fuel generated in the fuel tank 40 and supplies it to an intake pipe 20 of an internal combustion engine (not shown). Here, the intake pipe 20 forms an intake passage 21 for sending intake air to the internal combustion engine, and the throttle valve 22 adjusts the flow rate of intake air flowing through the intake passage 21. The intake passage 21 communicates with the canister 30 through a purge passage 23, and a purge valve 24 is installed in the purge passage 23. An air passage 50 that is open to the atmosphere communicates with the canister 30, and an air release valve 51 is installed in the air passage 50. The fuel tank 40 communicates with the canister 30 through a tank passage 41.

The canister 30 includes a canister case 31, a partition 60, and an adsorbent 70.
As shown in FIGS. 1 and 2, the canister case 31 is formed in a box shape by joining a plurality of members 311 and 312 made of resin or the like. Here, the vertical direction in FIG. 1 substantially coincides with the vertical direction in the actual use state of the canister 30, and hereinafter, the member 311 is referred to as an upper member 311, and the member 312 is referred to as a lower member 312. The top wall 313 of the upper member 311 is formed with an inflow port 32 that communicates with the tank passage 41, an outflow port 33 that communicates with the purge passage 23, and an atmospheric port 34 that communicates with the atmospheric passage 50.

  As shown in FIG. 1, the partition portion 60 is joined to the top wall portion 313 of the upper member 311, so that the inside of the canister case 31 has an intake chamber 35 on the side of the inflow port 32 and the outflow port 33, and an atmospheric port 34. It is divided into an air chamber 36 on the side. Further, the lower end portion of the partition portion 60 is separated from the bottom wall portion 314 of the lower member 312, whereby the intake chamber 35 and the atmospheric chamber 36 communicate with each other through the partition portion 60 and the bottom wall portion 314. is doing. Each of the adsorption chamber 35 and the atmospheric chamber 36 is filled with an adsorbent 70 made of granular activated carbon. Here, in the present embodiment, a pair of perforated plates 71 and 72 are installed in the canister case 31 with a space in the vertical direction, and each chamber is provided between the filters 73 and 74 supported by the perforated plates 71 and 72. The adsorbent 70 in 35 and 36 is sandwiched. In addition, in the present embodiment, the upper plate 71 is joined to the side wall portion 315 of the upper member 311, while the lower plate 72 holds the adsorbent 70 between the partition portion 60 and the spring. 75 is pressed upward. Therefore, in this embodiment, collapse of the adsorbent 70 is prevented. In FIG. 1, a part of the adsorbent 70 in each of the chambers 35 and 36 is not shown.

  The partition part 60 of the present embodiment is characterized in that it consists of a single Peltier element 61 having a plate shape. Specifically, the Peltier element 61 is arranged in such a manner that one surface 63 faces the suction chamber 35 and the other surface 64 faces the air chamber 36. In the following description, the surface 63 is the suction chamber side surface 63 and the surface 64. Is referred to as the atmospheric chamber side surface 64. The Peltier element 61 is electrically connected to an electronic control unit (ECU) 68 through a power supply driver 66, and the ECU 68 switches and controls the energization polarity to the Peltier element 61 by the power supply driver 66. Here, when the ECU 68 switches the energization polarity to the Peltier element 61 to the first polarity, the air chamber side surface 64 of the Peltier element 61 becomes the heat absorption surface, and the adsorption chamber side surface 63 becomes the heat dissipation surface. Therefore, at this time, heat is transferred from the adsorbent 70 in the atmospheric chamber 36 to the adsorbent 70 in the adsorption chamber 35 through the Peltier element 61, so that the adsorbent 70 in the atmospheric chamber 36 is cooled, while the adsorption The adsorbent 70 in the chamber 35 is heated. On the other hand, when the ECU 68 switches the energization polarity to the Peltier element 61 to the second polarity, the adsorption chamber side surface 63 becomes the heat absorption surface, while the air chamber side surface 64 of the Peltier element 61 becomes the heat dissipation surface. Therefore, at this time, heat is transferred from the adsorbent 70 in the adsorbing chamber 35 to the adsorbent 70 in the atmospheric chamber 36, so that the adsorbent 70 in the adsorbing chamber 35 is cooled, while in the atmospheric chamber 36. The adsorbent 70 is heated.

As shown in FIG. 2, the ECU 68 of the present embodiment is electrically connected to the valves 24 and 51 and has a function of controlling the valves 24 and 51. The ECU 68 may not have the function.
As described above, the ECU 68 and the power supply driver 66 jointly constitute “control means” described in the claims.

Next, the operation of the evaporated fuel processing apparatus 10 will be described.
In the adsorption period in which the evaporated fuel generated in the fuel tank 40 is adsorbed by the adsorbent 70 in the canister case 31, the ECU 68 is raised by the generation of evaporated fuel while the purge valve 24 is closed and the air release valve 51 is opened. Due to the internal pressure of the fuel tank 40, the evaporated fuel flows into the adsorption chamber 35 through the tank passage 41 and the inflow port 32. At this time, if the ECU 68 sets the energization polarity to the Peltier element 61 to the first polarity, the adsorbent temperature in the adsorption chamber 35 rises while the adsorbent temperature in the atmospheric chamber 36 falls. Therefore, of the adsorbents 70 in the chambers 35 and 36, the evaporated fuel is adsorbed in order from the adsorbent 70 in the adsorption chamber 35 that receives the internal pressure of the fuel tank 40 and rises in temperature.

  Further, in the desorption period in which the evaporated fuel adsorbed during the adsorption period is desorbed from the adsorbent 70 in the canister case 31, first, if the electrification polarity to the Peltier element 61 is the second polarity, While the adsorbent temperature increases, the adsorbent temperature in the adsorption chamber 35 decreases. As a result, a temperature gradient is formed at a low temperature from the atmosphere chamber 36 side toward the adsorption chamber 35 side, so that a gas flow from the atmosphere chamber 36 side toward the outflow port 33 on the adsorption chamber 35 side is generated. In this state, when the ECU 68 opens the purge valve 24 together with the air release valve 51, the negative pressure in the intake passage 21 acts into the adsorption chamber 35 through the purge passage 23 and the outflow port 33. At this time, if the ECU 68 sets the energization polarity to the Peltier element 61 to the first polarity, the adsorbent temperature in the adsorption chamber 35 rises while the adsorbent temperature in the atmospheric chamber 36 falls. Therefore, among the adsorbents 70 in the chambers 35 and 36, the evaporated fuel is desorbed in order from the adsorbent 70 in the adsorption chamber 35 that receives the negative pressure of the intake passage 21 and rises in temperature. Further, the desorbed evaporated fuel flows out of the canister case 31 through the outflow port 33 due to the negative pressure of the intake passage 21 and is purged to the intake passage 21 through the purge passage 23.

  According to the first embodiment described above, the adsorbent temperature in each of the chambers 35 and 36 can be adjusted by the common Peltier element 61 by different methods during the adsorption period and the desorption period. Therefore, according to the first embodiment, it is possible to improve the adsorption performance and the desorption performance of the evaporated fuel by an optimum method while simplifying the configuration of the canister 30.

(Second embodiment)
As shown in FIG. 3, the second embodiment of the present invention is a modification of the first embodiment.
In the canister 100 of the second embodiment, the partition 110 is formed by laminating two Peltier elements 111 and 112 having a plate shape. Specifically, the first Peltier element 111 is arranged such that one surface 113 faces the suction chamber 35 and the other surface 114 faces the second Peltier element 112, and the second Peltier element 112 has one surface. 115 is arranged such that 115 faces the first Peltier element 111 and the other surface 116 faces the air chamber 36. With such an arrangement, the first Peltier element 111 and the second Peltier element 112 are stacked in a substantially horizontal direction in which the adsorption chamber 35 and the atmospheric chamber 36 are arranged. In the following description, the surface 113 of the first Peltier element 111 is the suction chamber side surface 113, the surface 114 of the first Peltier element 111 is the stacked surface 114, the surface 115 of the second Peltier element 112 is the stacked surface 115, and the second Peltier element 112. This surface 116 is referred to as an atmospheric chamber side surface 116.

  Both the first and second Peltier elements 111 and 112 are electrically connected to the ECU 68 via the power supply driver 66, and the ECU 68 switches and controls the polarity of energization of the Peltier elements 111 and 112 by the power supply driver 66. To do. Here, when the ECU 68 switches the energization polarity to the Peltier elements 111 and 112 to the first polarity, the atmosphere chamber side surface 116 of the second Peltier element 112 and the laminated surface 114 of the first Peltier element 111 become heat absorption surfaces. The suction chamber side surface 113 of the first Peltier element 111 and the laminated surface 115 of the second Peltier element 112 serve as a heat radiating surface. Therefore, at this time, heat is transferred from the adsorbent 70 in the atmospheric chamber 36 to the adsorbent 70 in the adsorption chamber 35 through the Peltier elements 111 and 112, so that the adsorbent 70 in the atmospheric chamber 36 is cooled. On the other hand, the adsorbent 70 in the adsorption chamber 35 is heated. On the other hand, when the ECU 68 switches the energization polarity to the Peltier elements 111 and 112 to the second polarity, the adsorption chamber side surface 113 of the first Peltier element 111 and the laminated surface 115 of the second Peltier element 112 are the heat absorption surfaces. On the other hand, the atmosphere chamber side surface 116 of the second Peltier element 112 and the laminated surface 114 of the first Peltier element 111 are heat dissipation surfaces. Therefore, at this time, heat is transferred from the adsorbent 70 in the adsorbing chamber 35 to the adsorbent 70 in the atmospheric chamber 36 through the Peltier elements 111 and 112, so that the adsorbent 70 in the adsorbing chamber 35 is cooled. On the other hand, the adsorbent 70 in the atmospheric chamber 36 is heated.

  In such an adsorption period of the second embodiment, when the ECU 68 sets the energization polarity to the Peltier element 61 as the first polarity, the heat from the adsorbent 70 in the atmospheric chamber 36 to the adsorbent 70 in the adsorption chamber 35. The amount of movement increases compared to the case of the first embodiment. Therefore, a large temperature difference can be formed between the adsorbents 70 in the chambers 35 and 36, and the adsorption performance of the evaporated fuel can be improved.

  In the desorption period of the second embodiment, when the ECU 68 sets the energization polarity to the Peltier element 61 to the second polarity, the heat from the adsorbent 70 in the adsorption chamber 35 to the adsorbent 70 in the atmospheric chamber 36. The amount of movement increases compared to the case of the first embodiment. Therefore, it is possible to reliably generate a gas flow from the atmosphere chamber 36 side to the outflow port 33 on the adsorption chamber 35 side and to prevent the evaporated fuel from flowing out from the atmosphere port 34. Further, the ECU 68 sets the energization polarity to the Peltier element 61 to the first polarity in a state where the adsorbent 70 in the adsorption chamber 35 is cooled by setting the energization polarity to the Peltier element 61 to the second polarity. Then, the adsorbent temperature in the adsorption chamber 35 is greatly increased. Therefore, according to such a temperature rise, the desorption amount of the evaporated fuel increases from the adsorbent 70 in the adsorption chamber 35, so that the evaporative fuel desorption performance can be improved.

A plurality of embodiments of the present invention have been described so far, but the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. is there.
For example, the partition portion may be formed from three or more Peltier elements stacked in the direction in which the adsorption chamber 35 and the atmospheric chamber 36 are arranged, or substantially horizontal perpendicular to the direction in which the adsorption chamber 35 and the atmospheric chamber 36 are arranged. You may form a partition part from two or more Peltier elements arranged in the direction.

It is sectional drawing which shows the canister by 1st embodiment of this invention. It is a schematic diagram which shows the evaporative fuel processing apparatus to which the canister of FIG. 1 is applied. It is sectional drawing which shows the canister by 2nd embodiment of this invention.

Explanation of symbols

30, 100 canister, 31 canister case, 32 inlet port, 33 outlet port, 34 atmospheric port, 35 adsorption chamber, 36 atmospheric chamber, 60,110 partition, 61 Peltier element, 66 power driver (control means), 68 ECU ( Control means), 70 adsorbent, 111 first Peltier element (Peltier element), 112 second Peltier element (Peltier element)

Claims (4)

A canister case forming an inflow port through which evaporative fuel flows in, an outflow port through which evaporative fuel flows out, and an atmospheric port opened to the atmosphere;
Partitioning the inside of the canister case to form an adsorbing chamber on the inflow port and outflow port side and an air chamber on the air port side in an interconnected state, and the adsorbing chamber is energized by energization. And a partition having a Peltier element for transferring heat from one of the atmospheric chambers to the other,
An adsorbent filled in both the adsorption chamber and the atmospheric chamber;
Canister equipped with.   2. The canister according to claim 1, wherein the partition portion includes a plurality of the Peltier elements stacked in a direction in which the adsorption chamber and the atmospheric chamber are arranged.   The energization polarity to the Peltier element is between a first polarity for transferring heat from the atmospheric chamber to the adsorption chamber and a second polarity for transferring heat from the adsorption chamber to the atmospheric chamber. The canister according to claim 1 or 2, further comprising control means for switching control. In the desorption period in which the evaporated fuel is desorbed from the adsorbent and flows out of the canister case from the outflow port, the control means switches the polarity of the current supplied to the Peltier element to the second polarity. The canister according to claim 3, wherein the canister is switched to the first polarity.

Images