JP5939090B2 - Evaporative fuel processing equipment - Google Patents

Description

  The present invention relates to a fuel vapor processing apparatus.

  In a vehicle driven by an internal combustion engine, evaporated fuel generated in a fuel tank or the like is adsorbed by an adsorber (hereinafter also referred to as a canister) containing activated carbon or the like, and the fuel from the canister is operated during the operation of the internal combustion engine. An evaporative fuel processing device is provided that is desorbed and consumed by the internal combustion engine. In recent vehicles, there is a high demand for suppressing the diffusion of fuel vapor during refueling, and an improvement in canister performance is required.

  As a conventional evaporative fuel processing device, a canister is disposed on the inner bottom side of the fuel tank and in the vicinity of the fuel inlet to improve the cooling efficiency and adsorption performance of the canister, while the high temperature surplus that has not been used in an internal combustion engine. It is known that a return path for returning the fuel into the fuel tank is passed through the vicinity of the canister so as to improve the detachability of the canister during the purge operation (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 08-042405

  However, in the conventional evaporative fuel processing apparatus as described above, when the fuel temperature in the fuel tank is high, the canister immersed in the fuel liquid is heated by the fuel even when fuel adsorption is necessary, The cooling effect of the canister by refueling has been impaired by the high temperature fuel in the fuel tank. For this reason, it has been difficult to lower the temperature of the canister, which is an adsorber, to improve its fuel adsorption performance, or to sufficiently lower the temperature of the canister to suppress the diffusion of fuel vapor during refueling.

  Therefore, the present invention provides a fuel vapor processing apparatus that can suppress the temperature rise of the adsorber to improve the fuel adsorption performance, or can sufficiently reduce the temperature of the adsorber to suppress the diffusion of fuel vapor during refueling. The purpose is to provide.

  In order to achieve the above object, a fuel vapor processing apparatus according to the present invention is (1) an adsorber that is attached to a fuel tank and adsorbs evaporated fuel generated in the fuel tank, and desorbs fuel from the adsorber. And a purge mechanism for performing a purge operation for sucking a purge gas containing air and fuel desorbed from the adsorber into an intake pipe of the internal combustion engine, wherein the evaporated fuel processing apparatus is sucked into the internal combustion engine. The adsorber is exposed in a cooling passage through which the intake air passes, and an adsorber temperature adjustment mechanism is provided that can cool the adsorber when the intake air flows in the cooling passage. .

  In the evaporative fuel processing apparatus of the present invention, since a part of the adsorber is installed so as to be exposed in the cooling passage through which the intake air of the internal combustion engine passes, the canister is cooled when the intake air flows through the cooling passage. become. Therefore, by passing the intake air through the cooling passage in a timely manner, the temperature rise of the canister can be suppressed to improve the fuel adsorption performance, or the temperature of the canister can be lowered sufficiently during refueling to suppress the diffusion of fuel vapor during refueling. can do.

  Note that when the temperature of the canister is lowered to suppress the diffusion of fuel vapor during refueling, for example, if a warning system warns that the remaining fuel level is low, the travel period until the vehicle stops under that warning condition The canister can be cooled by the adsorber temperature control mechanism. Of course, it is also conceivable to grasp that the probability of refueling is high from some other sensor information.

  In the fuel vapor processing apparatus of the present invention, (2) the adsorber temperature adjustment mechanism causes the intake air to flow through the cooling passage when the temperature of the adsorber is higher than the outside air temperature, and the temperature of the adsorber is the outside air. You may have the flow control part which restrict | limits the flow of the said intake air in the said cooling passage when it is lower than temperature.

  In this case, outside air is introduced into the cooling passage when the temperature of the adsorber is higher than the outside air temperature, and the adsorber is reliably cooled. Of course, when the temperature difference between the adsorber temperature and the outside air temperature reaches a certain temperature, the outside air can be introduced into the cooling passage.

  In the fuel vapor processing apparatus having the configuration of (2), (3) the flow rate control unit is configured to control an upstream flow rate of the intake air in an upstream passage portion upstream of the adsorber in the cooling passage. And a downstream flow rate control valve capable of controlling the flow rate of the intake air in the downstream passage portion of the cooling passage downstream of the adsorber. The opening of the upstream flow control valve is reduced on the condition that the temperature is lower than the outside air temperature, and the downstream flow control valve is opened under the reduced opening state of the upstream flow control valve. The degree may be reduced.

  In this case, when the temperature of the adsorber becomes lower than the outside air temperature, the opening degree of the upstream flow rate control valve becomes small and the introduction of the high temperature outside air is restricted. In the meantime, a negative pressure can be generated in the cooling passage between the upstream and downstream flow control valves. Therefore, even if there is a temperature difference between the fuel in the fuel tank and the adsorber, the adsorber is warmed by the high-temperature fuel in the fuel tank (particularly outside the case) when the fuel is adsorbed, or when the fuel is desorbed. It becomes difficult to be cooled by the fuel in the tank, and the temperature of the adsorber can be kept at an appropriate temperature.

  In the fuel vapor processing apparatus having the configuration of (3), (4) the flow rate control unit is configured such that the upstream side flow rate control valve and the downstream side of the upstream side flow rate control valve are in a reduced opening state. The opening degree of the downstream flow rate control valve may be controlled so that the pressure of the cooling passage between the flow rate control valve and the flow rate control valve is maintained in a preset negative pressure state.

  In this case, the negative pressure generated in the cooling passage between the upstream and downstream flow control valves can be maintained for the required time, and the adsorber is heated or cooled by the fuel in the fuel tank during fuel adsorption. The adsorption performance and desorption performance of the adsorber can be secured stably by effectively suppressing the occurrence of the adsorption.

  In the fuel vapor processing apparatus having the configuration of (4) above, (5) the flow rate control unit is configured so that the upstream side flow rate control valve and the downstream side flow rate control valve are in the closed state of the upstream side flow rate control valve. When the pressure of the cooling passage between the flow control valve reaches a preset threshold pressure, the downstream flow control valve may be closed.

  Thereby, overload of the internal combustion engine can be avoided while protecting the member in which the cooling passage is formed.

  In the fuel vapor processing apparatus according to the present invention, (6) a fuel pump that pumps up and discharges the fuel in the fuel tank and supplies the fuel to the internal combustion engine, and returns the fuel discharged from the fuel pump toward the adsorber. A fuel recirculation mechanism that can be made to be installed in the fuel tank, and a case member that houses the adsorber is installed in the fuel tank, and the case member includes the cooling passage, A fuel storage chamber into which the recirculated fuel from the fuel recirculation mechanism flows is formed, and the adsorber may be exposed in the fuel storage chamber so as to be able to transfer heat.

  With this configuration, when the fuel recirculation mechanism recirculates the fuel discharged from the fuel pump, the adsorber that is pressurized and heated in the fuel pump and whose temperature is raised is accommodated in the fuel accommodation chamber and exposed in the fuel accommodation chamber Is heated by the fuel in the fuel storage chamber. Therefore, the desorption performance of the adsorber can be enhanced during operation of the internal combustion engine in which the fuel pump operates.

  In the evaporated fuel processing apparatus having the configuration of (6), (7) the fuel recirculation mechanism is configured to remove the fuel discharged from the fuel pump before or when the purge operation is performed by the purge mechanism. You may make it recirculate | reflux in the said fuel storage chamber.

  In this case, when the purge operation is executed by the purge mechanism, the desorption performance of the adsorber can be reliably improved.

  The start of refueling can be detected by, for example, a sensor for detecting the remaining amount of fuel when a system that warns of a decrease in the remaining amount of fuel is provided, but an openable fuel lid that covers the cap of the refueling port It can also be detected by detecting that a lid opening operation for opening the fuel is performed or detecting the opening of the fuel lid or the filler cap. Further, it is conceivable to grasp from the other sensor information indicating that the cap of the fuel filler opening has been removed or that the probability of the fuel supply is high.

  According to the present invention, since the fuel in the canister and the fuel tank can be cooled in a timely manner using the intake air of the internal combustion engine, the fuel adsorption performance is improved by suppressing the temperature rise of the canister, and the fuel vapor is diffused during refueling. It is possible to provide an evaporative fuel processing apparatus that can sufficiently reduce the temperature of the canister during refueling in order to suppress it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a main part including an internal combustion engine for driving driving and a fuel system thereof in a vehicle equipped with an evaporative fuel processing apparatus according to a first embodiment of the present invention. It is explanatory drawing of an example of the passage arrangement | positioning form in the evaporative fuel processing apparatus which concerns on 1st Embodiment of this invention, Fig.2 (a) is the principal part top view, FIG.2 (b) is the principal part top sectional drawing. FIG. 2 (c) is a diagram showing a developed image of the cooling passage when viewed in the IIC direction of FIG. 2 (b). FIG. 3A is a configuration diagram of a main part of an adsorber temperature adjustment mechanism showing an evaporative fuel processing apparatus according to a second embodiment of the present invention, and FIG. 3B is a diagram showing a developed image of the cooling passage. It is. It is a schematic block diagram of the principal part containing the internal combustion engine for driving | running | working driving | running | working of the vehicle carrying the evaporative fuel processing apparatus which concerns on 3rd Embodiment of this invention, and its fuel system. It is explanatory drawing of an example of the passage arrangement | positioning form in the evaporative fuel processing apparatus which concerns on 3rd Embodiment of this invention, Fig.5 (a) is the principal part top view, FIG.5 (b) is the deformation | transformation aspect of the principal part. FIG. It is a schematic block diagram of the principal part containing the internal combustion engine for driving | running | working driving | running | working of the vehicle carrying the evaporative fuel processing apparatus which concerns on 4th Embodiment of this invention, and its fuel system. It is explanatory drawing of an example of the passage arrangement | positioning form in the evaporative fuel processing apparatus which concerns on 4th Embodiment of this invention, Fig.7 (a) is sectional drawing of the principal part seen in the downward side in the horizontal cross section above the canister. FIG. 7B is a cross-sectional view of the main part seen from the upper side in a horizontal cross section below the canister, and FIG. 7C is a view showing a developed image of the cooling passage. It is explanatory drawing of the modification of the passage arrangement | positioning form in the evaporative fuel processing apparatus which concerns on 4th Embodiment of this invention, FIG. 8 (a) is the cross section of the principal part seen in the downward side in the horizontal cross section above the canister. FIG. 8B is a cross-sectional view of the main part seen from the upper side in a horizontal cross section below the canister, and FIG. 8C is a view showing a developed image of the cooling passage. FIG. 9A is a plan sectional view on the upper side of the canister showing a modification of the separation wall between the air introduction side chamber and the fuel introduction chamber in the case in the evaporative fuel processing apparatus according to the fourth embodiment of the present invention. FIG. 9B is a schematic diagram showing the arrangement of the cooling passages in one air introduction chamber as viewed in the direction of the arrow IXB in FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a configuration of a main part of a vehicle equipped with an evaporated fuel processing apparatus according to a first embodiment of the present invention, that is, an internal combustion engine for driving and a fuel system system for supplying and purging the fuel. ing. The internal combustion engine of the present embodiment uses a highly volatile fuel, and is mounted on, for example, a four-wheel automobile for driving driving.

  First, the configuration will be described.

  As shown in FIG. 1, the vehicle 1 according to the present embodiment includes an engine 2, a fuel supply mechanism 3 having a fuel tank 31, and a fuel purge system 4 constituting an evaporative fuel processing apparatus. It is configured to include.

  The engine 2 is a spark ignition type multi-cylinder internal combustion engine, for example, a 4-cycle in-line 4-cylinder engine.

  A plurality of cylinders 2a (only one is shown in FIG. 1) of the engine 2 are each provided with a piston 11 to form a combustion chamber 13, and an intake valve 16 and an exhaust valve 17 are mounted. In addition, injectors 21 (fuel injection valves) are respectively attached to the intake port portions of the plurality of cylinders 2 a, and the plurality of injectors 21 are connected to delivery pipes 22.

  The delivery pipe 22 is supplied with a highly volatile fuel (for example, gasoline) pressurized to a fuel pressure (fuel pressure) required for the engine 2 from a fuel pump 32 (described later) in the fuel tank 31. ing.

  An intake pipe 23 is connected to the intake port portion 2b of the engine 2, and the intake pipe 23 is provided with a surge tank 23a having a predetermined volume that suppresses intake pulsation and intake interference.

  An intake passage 23b is formed inside the intake pipe 23, and a throttle valve 24 that is driven by a throttle actuator 24a so that the opening degree can be adjusted is provided on the intake passage 23b. The throttle valve 24 adjusts the amount of intake air taken into the engine 2 by adjusting the opening of the intake passage 23b.

  The fuel supply mechanism 3 includes a fuel tank 31 mounted on a vehicle, a fuel pump 32 installed in the fuel tank 31, a fuel supply pipe 33 connecting the fuel tank 31 and the fuel pump 32, and a fuel pump 32. And a suction pipe 35 with a filter 34 provided on the upstream side.

  The fuel tank 31 is a fuel storage container having a predetermined volume arranged so that fuel can be supplied by refueling on the lower side of the vehicle body of the vehicle 1, and stores fuel consumed by the engine 2. And the fuel pump 32 as a feed pump is arrange | positioned in the predetermined position of the fuel tank 31, and is supported by the support mechanism which is not shown in figure.

  The fuel pump 32 is of a variable discharge capacity (discharge amount and discharge pressure) type that can pump up the fuel in the fuel tank 31 and pressurize it to a predetermined feed fuel pressure or more, and is constituted by a circumferential flow pump, for example. . The fuel pump 32 has an impeller for operating the pump and a built-in motor that drives the impeller, although a detailed internal configuration is not shown.

  The fuel pump 32 changes its discharge capacity per unit time by changing at least one of the rotational speed and rotational torque of the impeller for operating the pump according to the drive voltage and load torque of the built-in motor. It can be changed.

  The fuel supply pipe 33 extends from one end in the fuel tank 31 to the other end in the vicinity of the engine 2 so as to connect the fuel pump 32 and the delivery pipe 22 to each other.

  The suction pipe 35 forms a suction passage (not shown) on the upstream side of the fuel tank 31, and a fuel filter 34 is disposed in the most upstream portion of the suction passage. The fuel filter 34 is a known filter that filters the fuel sucked into the fuel pump 32.

  For convenience of explanation, in the following explanation, a pressure regulator 36 that controls the feed fuel pressure to the branch pipe 33b branched from the fuel supply pipe 33 in the fuel tank 31 (a relief valve that opens at a set pressure or a pressure reducing valve) It is assumed that the fuel pump 32 of the fuel supply mechanism 3 changes only the discharge amount. Here, the branch pipe 33 b and the pressure regulator 36 can recirculate excess fuel into the fuel tank 31 in accordance with the discharge pressure of the fuel from the fuel pump 32.

  On the other hand, the fuel tank 31 is provided with a fuel supply pipe 37 so as to extend from the fuel tank 31 to the side or the rear side of the vehicle. An oil supply port 37a is provided at the tip of the oil supply pipe 37 in the protruding direction, and the oil supply port 37a is closed by a cap 37b. Further, the fuel filler opening 37 a is disposed in a fuel inlet box 38 provided in the body (not shown in detail) of the vehicle 1. The fuel inlet box 38 is opened when refueling, and is closed by the fuel lid 39 when not refueling.

  The fuel supply pipe 37 is closed at least by its own weight (by an urging force from a spring (not shown)), thereby preventing the backflow / outflow of fuel from the inside of the fuel tank 31 to the upstream portion in the fuel supply pipe 37. A backflow prevention valve 37v is provided. The reverse flow prevention valve 37v is configured to allow the inside of the fuel tank 31 and the upstream portion in the oil supply pipe 37 to communicate with each other when the valve opening operation is performed with fuel flowing down during refueling.

  When fuel is supplied, a fuel lid opening request lever (not shown) in the passenger compartment is operated, and the fuel lid 39 is opened in response to the lever operation. The fuel can be injected into the fuel tank 31 from the fuel filler port 37a by removing the cap 37b detachably attached to the fuel filler port 37a.

  The fuel purge system 4 is interposed between the fuel tank 31 and the intake pipe 23. Specifically, the fuel purge system 4 is connected to the fuel tank 31 and the surge tank 23a by piping.

  The fuel purge system 4 includes a canister 41 (adsorber) capable of adsorbing and holding evaporated fuel (also referred to as fuel vapor) generated in a fuel tank 31, and an intake pipe by desorbing fuel from the canister 41. 23 and a purge control mechanism 45 for controlling the operation of the purge mechanism 42.

  Further, the fuel purge system 4 is configured such that the evaporated fuel generated in the fuel tank 31 can be discharged into the intake passage 23b and combusted during intake of the engine 2.

  The canister 41 has a built-in adsorbent 41b such as activated carbon in a confidential canister case 41a, and is installed in the fuel tank 31 so as to be slightly separated from the inner bottom surface 31b. The inside of the canister 41 (adsorbent storage space) communicates with the upper space in the fuel tank 31 through the evaporation pipe 61 and the gas-liquid separation valve 62. Therefore, the canister 41 can adsorb the evaporated fuel by the adsorbent 41 b when the fuel evaporates in the fuel tank 31 and the evaporated fuel accumulates in the upper space in the fuel tank 31. Further, when the fuel level in the fuel tank 31 rises or the liquid level fluctuates, the gas-liquid separation valve 62 having a check valve function rises to close the tip of the evaporation pipe 61.

  The purge mechanism 42 includes a purge passage pipe 43 that allows the inside of the canister 41 to communicate with the internal portion of the surge tank 23 a in the intake passage 23 b of the intake pipe 23, and the inside of the canister 41, for example, the inside of the fuel inlet box 38. And an atmospheric passage pipe 44 that is opened to the atmospheric pressure space.

  When a negative pressure is generated inside the surge tank 23 a during operation of the engine 2, the purge mechanism 42 introduces a negative pressure to one end side inside the canister 41 through the purge passage pipe 43, while the other end inside the canister 41. The air can be introduced to the side through the air passage pipe 44. Therefore, the purge mechanism 42 can desorb (release) the fuel adsorbed by the adsorbent 41b of the canister 41 and held in the canister 41 from the canister 41 and suck the fuel into the surge tank 23a.

  The purge control mechanism 45 detects the temperature of a purge negative pressure switching solenoid valve (hereinafter referred to as “purge VSV”) 46, an electronic control unit (hereinafter referred to as “ECU”) 47 that controls this purge VSV 46, and the canister 41. A canister temperature sensor 48, a sender gauge 49 for measuring the remaining amount of fuel in the fuel tank 31 (may be a sensor for detecting a shortage of the remaining amount, a remaining amount calculation program, etc.), and an outside air temperature sensor 66. ing.

  The purge VSV 46 is provided in the middle of the purge passage pipe 43. The purge VSV 46 can variably control the amount of fuel desorbed from the canister 41 by changing the opening degree in the middle of the purge passage pipe 43. Specifically, the purge VSV 46 can change the opening degree by duty-controlling the excitation current, and the canister 41 can be changed by the intake negative pressure in the intake pipe 23 at a purge rate corresponding to the duty ratio. The fuel desorbed from the fuel can be sucked into the surge tank 23a as purge gas together with air.

  The ECU 47 can control the purge rate by controlling the opening degree (for example, duty ratio) of the purge VSV 46 based on various sensor information.

  As described above, the fuel purge system 4 includes the fuel supply mechanism 3 from the fuel tank 31 to the engine 2, in particular, the canister 41 that adsorbs the evaporated fuel generated in the fuel tank 31, and the canister 41 through the air through the canister 41. The purge mechanism 42 that executes a purge operation for releasing the gas and the purge gas containing the fuel and air into the intake pipe 23 and the purge gas VSV 46 controls the intake amount of the purge gas into the intake pipe 23 to control the engine 2. And a purge control mechanism 45 that suppresses fluctuations in the air-fuel ratio.

  The fuel purge system 4 can adsorb the fuel vapor evaporated in the fuel tank 31 to the canister 41 even when the engine 2 is stopped. Further, the fuel purge system 4 opens the purge VSV 46 when the opening degree of the throttle valve 24 becomes smaller than a preset opening degree under a predetermined operation state of the engine 2, for example. Yes.

  On the other hand, the canister 41 is housed in a case member 50 disposed inside the fuel tank 31, and is supported at a predetermined position in the fuel tank 31 together with the fuel pump 32 via the case member 50.

  The case member 50 includes a cooling passage 51 through which intake air drawn into the engine 2 is passed, a fuel storage chamber 52 that stores a part of the fuel stored in the fuel tank 31, a purge passage pipe 43, and an atmospheric passage. Pipe insertion paths 53 and 54 through which the pipe 44 passes are respectively formed.

  The canister case 41a of the canister 41 is a material having heat transfer characteristics (specifically, heat conductivity, heat transfer rate with air, and heat transfer rate with fuel) that is higher than the material of the case member 50. The outer peripheral wall 41c is exposed to the inside of the cooling passage 51 and the fuel storage chamber 52 so that heat can be transferred.

  Specifically, the case member 50 includes an outer cylindrical wall portion 50a that houses the canister 41, and an inner cylindrical wall portion 50b that is coaxially disposed inside the outer cylindrical wall portion 50a with a predetermined separation distance therebetween. And at least a pair of separation walls 50c extending in the radial direction and the axial direction of the two cylindrical wall portions 50a and 50b between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b.

  And in the divided cylindrical shape (FIGS. 2A and 2B) divided into a plurality of parts by at least a pair of separation walls 50c between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b of the case member 50. A cooling passage 51 and a fuel storage chamber 52 are formed in the inner chamber portions 55a and 55b each having a semi-cylindrical cross section. Here, the one inner chamber portion 55 a on the atmosphere side is cut off from the internal space of the fuel tank 31, and can communicate only with the atmospheric pressure space outside the fuel tank 31 and the intake passage 23 b of the engine 2. The other inner chamber portion 55 b can communicate with the internal space of the fuel tank 31.

  Specifically, the cooling passage 51 formed in the inner chamber portion 55a is formed by a plurality of passage walls 50e and 50f between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b as shown in FIG. The shape of the passage meanders so as to be folded back multiple times. Further, as shown in FIG. 2 (b), the fuel storage chamber 52 formed in the inner chamber portion 55b is formed inside the fuel tank 31 by a plurality of communication ports 55h formed at equal angular intervals in the outer cylinder wall portion 50a. The fuel stored in is free to enter and exit.

  Further, the downstream portion 37 d of the fuel supply pipe 37 is connected to a semi-cylindrical portion of the outer cylindrical wall portion 50 a that covers the inner chamber portion 55 a of the case member 50, and fuel oil is supplied into the fuel tank 31 through the fuel supply pipe 37. When injected, the fuel flows into the fuel storage chamber 52. Accordingly, even when the fuel temperature in the fuel tank 31 is relatively high, the temperature of the fuel flowing into the fuel storage chamber 52 becomes a low temperature close to the fuel supply fuel temperature, and the outer periphery of the canister case 41a is placed in the fuel storage chamber 52. The canister 41 that exposes a part of the wall portion 41 c is effectively cooled by the low-temperature fuel in the fuel storage chamber 52.

  The fuel storage chamber 52 of the case member 50 communicates with the inside of the fuel tank 31 through a plurality of communication ports 55h on the lower side thereof, and also on the upper side thereof through the upper end opening 55j of the case member 50. 31 communicates with the inside.

  As shown in FIG. 1, the pair of separation walls 50c are integrally connected to the upper and lower sides of the canister 41 so as to hermetically partition the inner chamber portions 55a and 55b, as shown in FIG. 50b may be eliminated. In this case, an inner chamber portion 55a is formed by the outer cylindrical wall portion 50a, the semi-cylindrical inner cylindrical wall portion 50b, and the pair of separation walls 50c.

  In addition, as shown in FIG. 2A, the outer cylindrical wall portion 50 a and the inner cylindrical wall portion 50 b can be formed in a cylindrical shape having substantially the same length, and disk-like spaces can be formed above and below the canister 41. The connection positions of the purge passage pipe 43 and the atmospheric passage pipe 44 to the canister 41 are arbitrary.

  Of the outer peripheral wall portion 41c of the canister case 41a, the cooling wall surface portion 41c1 (see FIG. 2B) exposed in the cooling passage 51 has a heat transfer coefficient between the cooling air and the inner wall of the cooling passage 51 of the case member 50. It is set to be larger than that of the surface portion 51a (equivalent or larger heat transfer coefficient). Further, the cooling wall surface portion 41c2 exposed in the fuel storage chamber 52 in the outer peripheral wall portion 41c of the canister case 41a has a heat transfer coefficient with the fuel higher than that of the inner wall surface portion 52a of the fuel storage chamber 52 of the case member 50. Is set to be large.

  Then, when the canister 41 has a temperature higher than the outside air temperature due to heat generated when the fuel is adsorbed (heat generated when the activated carbon is adsorbed), the intake air drawn into the engine 2 passes through the cooling passage 51 of the case member 50. As a result, the canister 41 in which a part of the outer peripheral wall portion 41c (cooling wall surface portion 41c1) of the canister case 41a is exposed in the cooling passage 51 is cooled by the intake air.

  Further, when the temperature inside the canister 41 becomes higher than the temperature of the fuel in the fuel tank 31 due to heat generation during fuel adsorption, a part of the outer peripheral wall portion 41c of the canister case 41a (cooling wall surface) is placed in the fuel storage chamber 52. The canister 41 exposing the portion 41 c 2) is effectively cooled by the fuel in the fuel tank 31.

  Furthermore, when the temperature of the fuel in the fuel tank 31 and the canister 41 are both higher than the outside air temperature, when the intake air taken into the engine 2 passes through the cooling passage 51 of the case member 50, the canister 41 is cooled. In addition to the fuel in the fuel tank 31, the fuel in the fuel storage chamber 52 that directly contacts the canister 41 is cooled together with the canister 41.

  Therefore, when the internal temperature of the canister 41 or the temperature of the fuel in the fuel tank 31 is higher than the outside air temperature, the canister 41 is moved by passing cooling air through the cooling passage 51 of the case member 50 or increasing its passing flow rate. It can be cooled accurately.

  The flow rate of the cooling air passing through the cooling passage 51 of the case member 50 can be variably controlled according to the opening degree of the cooling control valve 56 disposed in the middle of the cooling passage 51. The ECU 47 is configured to perform opening / closing control or opening degree control (hereinafter simply referred to as “opening / closing control”).

  The cooling control valve 56 and the ECU 47 constitute an adsorber temperature adjusting mechanism 58 together with upstream and downstream cooling pipes 57a and 57b connected to the case member 50 so as to allow the cooling air to pass through the cooling passage 51. .

  The adsorber temperature adjustment mechanism 58 allows the intake air to flow through the cooling passage 51 when the temperature of the canister 41 is higher than the outside air temperature detected by the outside air temperature sensor 66, while the temperature of the canister 41 is lower than the outside air temperature. Sometimes, a cooling control valve 56 and an ECU 47 are provided as a flow rate control unit that restricts the flow of intake air in the cooling passage 51.

  In addition, the ECU 47 warns that the remaining amount of fuel is insufficient when it is predicted that the remaining amount of fuel will be insufficient within a certain travel distance from detection information such as a sender gauge 49 that measures the remaining amount of fuel in the fuel tank 31, for example. It also has a warning system function.

  The ECU 47 determines whether or not the temperature of the canister 41 is higher than the outside air temperature detected by the outside air temperature sensor 66 when a warning occurrence state (a state where a fuel warning or the like is lit) is generated. Determine whether. When it is determined that the temperature of the canister 41 is higher than the outside air temperature detected by the outside air temperature sensor 66, the cooling control valve 56 is opened during the traveling period until the vehicle stops under the warning state, and the cooling passage The canister 41 is cooled by the cooling air passing through 51.

  The ECU 47 determines, based on some sensor information, whether or not fuel supply to the fuel tank 31 is executed under the remaining amount warning state, or whether or not the probability of the fuel supply execution is high, and to the fuel tank 31. The canister 41 may be cooled in order to suppress the diffusion of the fuel vapor when it is determined that the refueling is performed (the probability of refueling is high). It is also conceivable that when the engine 2 is stopped, the air suction mechanism is operated by another power source so that the canister 41 is cooled by the cooling air passing through the cooling passage 51.

  Next, the operation will be described.

  In the fuel vapor processing apparatus of the present embodiment configured as described above, a part of the outer peripheral wall 41c of the canister case 41a of the canister 41 is exposed in the cooling passage 51 through which the intake air sucked into the engine 2 is passed. Therefore, when the temperature of the canister 41 is higher than the outside air temperature, the intake air flows through the cooling passage 51 at an appropriate time. On the other hand, the canister 41 is heated to a temperature higher than the temperature around it due to the adsorption of the evaporated fuel, and the fuel in the fuel tank 31 provided with the fuel pump 32 and the pressure regulator 36 is also relatively hot during the operation of the engine 2. Become. Therefore, the fuel in the canister 41 and the fuel tank 31 is cooled by the simple adsorber temperature adjustment mechanism 58 using the intake air of the engine 2 to suppress the temperature rise of the canister 41 and improve the fuel adsorption performance than before, or at the time of refueling The temperature of the canister can be lowered sufficiently during refueling in order to suppress the diffusion of fuel vapor. In addition, since the intake negative pressure of the engine 2 is used, there is no need to separately provide other equipment such as a compressor or a negative pressure source for air cooling.

  In the present embodiment, the ECU 47 of the adsorber temperature adjustment mechanism 58 causes the intake air to flow through the cooling passage 51 when the temperature of the canister 41 is higher than the outside air temperature due to heat generated by the adsorbent 41b due to fuel adsorption. On the other hand, when the temperature of the canister 41 is lower than the outside air temperature, the flow of the intake air in the cooling passage 51 is restricted in cooperation with the cooling control valve 56. Therefore, when outside air is introduced into the cooling passage 51, the canister 41 can be reliably cooled.

  Furthermore, in this embodiment, when a warning occurrence state that warns of a decrease in the remaining amount of fuel in the fuel tank 31 occurs, it is determined whether or not the temperature of the canister 41 is higher than the outside air temperature, and the temperature of the canister 41 is the outside air temperature. When it is determined that the temperature is higher, the cooling control valve 56 is opened during the traveling period until the vehicle stops under the warning state, and the canister 41 is cooled by the cooling air passing through the cooling passage 51. Therefore, the temperature of the canister 41 can be sufficiently lowered at the start of refueling or immediately after the start of refueling to effectively suppress the diffusion of fuel vapor during refueling.

  In addition, at the time of refueling, fuel fuel is preferentially injected into the fuel tank 31 through the fuel supply pipe 37, so that even if the fuel temperature in the fuel tank 31 is relatively high, it flows into the fuel storage chamber 52. The temperature of the fuel to be used becomes a low temperature close to the fuel supply fuel temperature. As a result, the canister 41 that exposes a part of the outer peripheral wall portion 41c of the canister case 41a in the fuel storage chamber 52, particularly the adsorbent 41b in the canister 41, is directly effected by the low-temperature fuel in the fuel storage chamber 52. Therefore, the fuel adsorption performance of the canister 41 can be enhanced.

  In addition, when the temperature of the canister 41 rises due to fuel adsorption and the temperature of the fuel in the fuel storage chamber 52 that directly contacts the canister 41 among the fuel in the fuel tank 31 also rises, the intake air is supplied to the cooling passage 51. By flowing, not only the canister 41 but also the fuel in the fuel storage chamber 52 can be effectively cooled, and heat can be directly transferred from the fuel outside the case member 50 in the fuel tank 31 to the canister 41. Absent. As a result, even if the temperature of the fuel inside the fuel tank 31 and outside the case member 50 is high, the canister 41 is effectively suppressed from being warmed by the high-temperature fuel, and the temperature rise is effectively suppressed. be able to.

  As described above, in the evaporated fuel processing apparatus of the present embodiment, the fuel in the canister 41 and the fuel tank 31 is supplied using the intake air of the engine 2 without refueling or using other equipment such as a compressor. Since the cooling can be performed in a timely and effective manner, the temperature of the canister 41 can be lowered sufficiently to reduce the temperature of the canister 41 in order to improve the fuel adsorption performance by reducing the temperature of the canister 41 or to suppress the diffusion of fuel vapor during refueling. You can make it.

(Second Embodiment)
FIG. 3 shows a main configuration of the adsorber temperature adjustment mechanism in the evaporated fuel processing apparatus according to the second embodiment of the present invention. In addition, although the structure of the adsorber temperature adjustment mechanism is different from the above-mentioned 1st Embodiment, the other structure of the evaporative fuel processing apparatus of this embodiment is the same as that of 1st Embodiment. Therefore, about the structure similar to 1st Embodiment, the code | symbol similar to FIG. 1 and FIG. 2 is attached | subjected in FIG. 3, and the difference mainly from 1st Embodiment is demonstrated hereafter.

  In the evaporative fuel processing apparatus of this embodiment, the divided cylindrical inner chamber portion 55a divided into a plurality of parts by at least a pair of separation walls 50c between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b of the case member 50, A cooling passage 51 and a fuel storage chamber 52 similar to those in the first embodiment are formed in 55b.

  The adsorber temperature adjustment mechanism 58 includes an upstream flow rate control valve 56A capable of controlling the flow rate of intake air in the upstream passage portion 51u upstream of the canister 41 in the cooling passage 51, and the canister 41 in the cooling passage 51. A downstream flow rate control valve 56B capable of controlling the flow rate of intake air in the downstream side passage portion 51d, and upstream and downstream cooling pipes 57a and 57b are provided. Further, the adsorber temperature adjustment mechanism 58 is a pressure sensor that detects the air pressure in the closeable passage section 51p (see FIG. 3B) between the upstream flow control valve 56A and the downstream flow control valve 56B. 67, and the upstream flow control valve 56A and the downstream flow control valve 56B are controlled based on the operating state of the engine 2, the detection information of the canister temperature sensor 48, the sender gauge 49, the outside air temperature sensor 66, and the pressure sensor 67, and the like. ECU47 which performs.

  In this embodiment, a cooling control valve 56C on the most downstream side corresponding to the cooling control valve 56 in the evaporated fuel processing apparatus of the first embodiment is additionally provided on the downstream side of the flow control valve 56B on the downstream side. Yes. However, one cooling control valve may be used as the downstream flow control valve 56B and the most downstream cooling control valve 56C.

  The ECU 47 of the adsorber temperature adjustment mechanism 58 allows the intake air to flow through the cooling passage 51 when the temperature of the canister 41 is higher than the outside air temperature detected by the outside air temperature sensor 66, while the temperature of the canister 41 is lower than the outside air temperature. When the temperature is low, the flow control valve 56A on the upstream side, the flow control valve 56B on the downstream side, and the cooling control valve 56C on the most downstream side are controlled so as to limit the flow of the intake air in the cooling passage 51.

  Further, the ECU 47 as the flow rate control unit only restricts the flow of the intake air in the cooling passage 51 by opening and closing at least the upstream flow rate control valve 56A and the downstream flow rate control valve 56B at different timings. Instead, at the time of the restriction, the air pressure in the closeable passage section 51p between at least the upstream flow control valve 56A and the downstream flow control valve 56B in the cooling passage 51 is variably controlled.

  That is, the ECU 47 first switches the upstream flow control valve 56A to a reduced opening state, for example, a closed state. Then, in the reduced opening state, the closeable passage section 51p between the upstream flow control valve 56A and the downstream flow control valve 56B is set in a negative pressure state (air pressure lower than atmospheric pressure) set in advance. Based on the detection information of the pressure sensor 67, the opening degree of the downstream flow control valve 56 </ b> B is controlled so as to be held. Further, the ECU 47 stops the flow of air in the cooling passage 51 by fully closing the upstream flow control valve 56A and the downstream flow control valve 56B while maintaining the negative pressure state of the closeable passage section 51p. In addition, the negative pressure state of the closeable passage section 51p is maintained.

  More specifically, the ECU 47 sets the detected pressure of the pressure sensor 67 from the atmospheric pressure in a closed state of the upstream flow control valve 56A (from the viewpoint of the strength and sealing performance of the case member 50). When the pressure decreases to a preferable negative pressure value), the downstream flow control valve 56B is closed. The ECU 47 may control the upstream flow control valve 56A and the downstream flow control valve 56B based on the temperature of the canister 41, the outside air temperature, and the fuel temperature in the fuel tank 31. For example, when the temperature of the canister 41 is slightly higher than the outside air temperature but lower than the fuel temperature, the upstream flow control valve 56A is switched to a reduced opening state, or the upstream flow control valve 56A and the downstream flow control valve 56A are switched. The flow control valve 56B may be fully closed.

  In this embodiment as well, the intake air of the engine 2 can be used to cool the fuel in the canister 41 and the fuel tank 31 at the time of refueling or the like, so that the temperature of the canister 41 is lowered to absorb the fuel. The temperature of the canister 41 can be sufficiently lowered at the time of refueling in order to improve performance or suppress the diffusion of fuel vapor at the time of refueling.

  In addition, in the present embodiment, when the temperature of the canister 41 becomes lower than the outside air temperature or the like, first, the opening degree of the upstream flow control valve 56A becomes small and the introduction of the high temperature outside air is restricted. The negative pressure can be generated in the cooling passage 51 between the upstream and downstream flow control valves 56A and 56B until the opening degree of the flow control valve 56B decreases.

  Furthermore, the negative pressure and the air flow rate generated in the cooling passage 51 between the upstream and downstream flow control valves 56A and 56B by the opening control of the upstream and downstream flow control valves 56A and 56B are optimal values. The state can be maintained for a required time while being controlled.

  Therefore, even if there is a temperature difference between the fuel in the fuel tank 31 and the canister 41, the canister 41 is warmed by the fuel in the tank outside the case member 50 when the fuel is adsorbed, or outside the case member 50 when the fuel is desorbed. It becomes difficult to be cooled by the fuel in the tank. As a result, the temperature of the canister 41 can be maintained at an appropriate temperature, and the adsorption performance and desorption performance of the canister 41 can be secured stably.

  In addition, in this embodiment, when the pressure in the closeable passage section 51p of the cooling passage 51 reaches a preset threshold pressure under the closed state of the upstream flow control valve 56A, the downstream flow control valve Since the valve 56B is closed, it is possible to prevent the engine 2 from being overloaded while protecting the case member 50 in which the cooling passage 51 is formed.

(Third embodiment)
FIG. 4 and FIG. 5 show a schematic configuration of a main part including an internal combustion engine for driving and its fuel system of a vehicle equipped with an evaporative fuel processing apparatus according to a third embodiment of the present invention.

  The evaporative fuel processing apparatus of this embodiment is different from the second embodiment in the arrangement of the cooling passage in the adsorber temperature adjustment mechanism, but the other configurations are substantially the same as those in the second embodiment. Therefore, about the structure similar to 2nd Embodiment, the code | symbol similar to FIGS. 1-3 is attached | subjected in FIG.4 and FIG.5, and the point which is mainly different from 2nd Embodiment below is demonstrated.

  In the evaporative fuel processing apparatus of this embodiment, as in the second embodiment, an upstream flow rate control valve capable of controlling the flow rate of intake air in the upstream passage portion 51u upstream of the canister 41 in the cooling passage 51. 56A is mounted on the upstream side cooling pipe 57a, and the downstream side flow control valve 56B capable of controlling the flow rate of the intake air in the downstream side passage part 51d downstream of the canister 41 in the cooling path 51 is provided on the downstream side cooling pipe. 57b.

  However, in the present embodiment, as shown in FIG. 5, the upstream side cooling pipe 57a is connected to the atmospheric passage pipe 44 at its upstream end side, and the downstream side cooling pipe 57b is connected to the purge passage pipe 43 at its downstream end side. It is connected to the.

  That is, the atmospheric passage pipe 44 is a single pipe that is opened to the atmospheric pressure space on the upstream side, but the canister side atmospheric pipe portion 44b connected to the canister 41 and the upstream side cooling pipe 57a on the downstream side. It is branched to. On the other hand, the purge passage pipe 43 is a single pipe opened into the surge tank 23a on the downstream side, but the canister side purge pipe portion 43b connected to the canister 41 and the downstream side cooling pipe 57b on the upstream side. And branching.

  As a result, the required cooling passage 51 communicating with the intake passage 23b from the atmospheric pressure space through the inner chamber portion 55a is formed while shortening the piping length of the upstream side cooling pipe 57a and the downstream side cooling pipe 57b. ing.

  Also in this embodiment, the ECU 47 of the adsorber temperature adjustment mechanism 58 allows the intake air to flow through the cooling passage 51 when the temperature of the canister 41 is higher than the outside air temperature detected by the outside air temperature sensor 66, while the canister 41. When the temperature is lower than the outside air temperature, the upstream flow control valve 56A, the downstream flow control valve 56B, and the most downstream cooling control valve 56C are controlled so as to limit the flow of the intake air in the cooling passage 51. .

  Further, the ECU 47 controls opening and closing of the upstream flow control valve 56A and the downstream flow control valve 56B based on detection information from the canister temperature sensor 48, the sender gauge 49, the outside air temperature sensor 66, the pressure sensor 67, and the like. Thus, the air pressure in the closeable passage section 51p of the cooling passage 51 is variably controlled or kept in a negative pressure state.

  In this embodiment as well, as in the first and second embodiments, the fuel in the canister 41 and the fuel tank 31 can be cooled in a timely manner using the intake air of the engine 2, so that the temperature of the canister 41 is lowered. Thus, the temperature of the canister 41 can be sufficiently lowered during refueling in order to improve the fuel adsorption performance or suppress the diffusion of fuel vapor during refueling.

  Moreover, in the present embodiment, the cooling length for cooling the canister 41 without reducing the length of the upstream cooling pipe 57a and the downstream cooling pipe 57b and without increasing the number of pipes outside the fuel tank 31 is provided. The passage 51 can be formed, and the evaporated fuel processing apparatus can be obtained at low cost with improved performance of the canister 41.

(Fourth embodiment)
6 and 7 show the configuration of the main part of the adsorber temperature adjustment mechanism in the evaporated fuel processing apparatus according to the fourth embodiment of the present invention. The evaporative fuel processing apparatus of this embodiment is different from the first embodiment in the configuration of the fuel supply mechanism and the cooling passage configuration of the adsorber temperature adjustment mechanism, but the other configurations are the same as those in the first embodiment. Is. Therefore, about the structure similar to 1st Embodiment, the code | symbol similar to FIG. 1 and FIG. 2 is attached | subjected in FIG. 6, and the difference mainly from 1st Embodiment is demonstrated hereafter.

  In the fuel vapor processing apparatus of the present embodiment, a reduction valve 76 (an electromagnetic relief valve that can be forcibly opened by a valve opening drive signal) is provided in the fuel tank 31 in the middle of a branch pipe 33b that branches from the fuel supply pipe 33. May be provided). The branch pipe 33b and the reducing valve 76 together with the ECU 47 selectively select a part of the fuel discharged from the fuel pump 32 (at least a part of the discharge amount within the unit time, the same applies hereinafter) in the fuel tank 31. A fuel recirculation mechanism 77 for recirculation is configured. Specifically, when the ECU 47 opens the purge VSV 46 of the purge control mechanism 45 and executes the purge operation by the purge mechanism 42, the ECU 47 first period from a predetermined time before starting the purge operation to the start of the purge operation. A part of the fuel discharged from the fuel pump 32 is supplied to the fuel tank during at least one of the period (before the purge operation is performed) and the second period during which the purge operation is performed (when the purge operation is performed). The reduction valve 76 is opened so as to be recirculated into the valve 31.

  Further, the fuel pump 32 of the fuel supply mechanism 3 is configured to change the fuel supply amount and the fuel supply pressure to the engine 2 side in cooperation with the reduction valve 76 of the fuel recirculation mechanism 77. However, the discharge capacity of the fuel pump 32 and the opening (valve opening duty) of the reducing valve 76 are controlled based on the required values of the fuel supply amount and the fuel supply pressure according to the operating state of the engine 2. .

  Here, the fuel pump 32 and the fuel recirculation mechanism 77 are each installed in the fuel tank 31, and the case member 50 that houses the canister 41 is also installed in the fuel tank 31.

  In the case member 50, in addition to the cooling passage 51 described above, the fuel recirculation mechanism 77 accommodates fuel when the fuel recirculation mechanism 77 recirculates part of the fuel discharged from the fuel pump 32 into the fuel tank 31. A chamber 52 is formed, and a part of the outer peripheral wall 41c of the canister 41 is exposed in the fuel storage chamber 52 so as to be able to transfer heat.

  In FIG. 6, the downstream portion 37d of the oil supply pipe 37 is not connected to the semi-cylindrical portion of the outer cylindrical wall portion 50a that covers the inner chamber portion 55a of the case member 50, but is the same as in the first embodiment. Needless to say, when fuel oil is injected into the fuel tank 31 through the fuel supply pipe 37, the fuel can flow into the fuel storage chamber 52.

  As shown in FIGS. 7 (a) to 7 (c), a pair of separations for dividing the space between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b of the case member 50 into divided cylindrical inner chamber portions 55a and 55b. The wall 50c is integrated at the top and bottom of the canister 41, and forms a single plate surrounding the canister 41 along a vertical plane. Further, on the inner chamber portion 55b side, the inner cylindrical wall portion 50b is only a portion that forms the outer peripheral wall portion 41c of the canister case 41a of the canister 41, and the fuel storage chamber 52 extends above and below the canister 41 while separating wall 50c. The concave surface is in contact with the entire surface of the canister 41 on one side.

  On the other hand, on the inner chamber portion 55a side, the inner cylindrical wall portion 50b extends upward from the upper surface of the canister 41. As shown in FIG. 7A, the semicylindrical inner cylindrical wall portion is located above the canister 41. A semicircular disk-like upper space 50j surrounded by 50b and the separation wall 50c and communicating with the atmospheric pressure space through the atmospheric passage pipe 44 is formed. Further, as shown in FIG. 7 (b), below the canister 41, a semicircular lower part surrounded by the inner cylindrical wall part 50b and the separation wall 50c and communicating with the inside of the surge tank 23a through the purge passage pipe 43 is provided. A space 50k is formed. The atmospheric inlet 41e of the canister 41 is opened in the upper space 50j, and the purge gas outlet 41g of the canister 41 is opened in the lower space 50k.

  Further, as shown in FIG. 7C, the cooling passage 51 formed in the inner chamber portion 55a is moved a plurality of times by a plurality of passage walls 50e and 50f between the outer cylindrical wall portion 50a and the inner cylindrical wall portion 50b. The shape of the passage meanders so as to be folded. Further, as shown in FIG. 7B, for example, the fuel storage chamber 52 formed in the inner chamber portion 55b is connected to the fuel tank 31 by a plurality of communication ports 55h formed at equiangular intervals in the outer cylinder wall portion 50a. The fuel stored inside is free to enter and exit.

  Also in the present embodiment, the fuel in the canister 41 and the fuel tank 31 can be cooled in a timely manner using the intake air of the engine 2 as in the first and second embodiments. The temperature of the canister 41 can be sufficiently lowered at the time of refueling in order to improve the fuel adsorption performance or suppress the diffusion of fuel vapor at the time of refueling.

  Moreover, in the present embodiment, when the fuel recirculation mechanism 77 recirculates a part of the fuel discharged from the fuel pump 32 into the fuel tank 31, especially when the purge operation is executed by the purge mechanism 42, Since the fuel whose temperature has been raised is stored in the fuel storage chamber 52, the canister 41 exposed in the fuel storage chamber 52 is warmed by the fuel in the fuel storage chamber 52. Therefore, the temperature of the canister 41 can be raised by the fuel in the fuel storage chamber 52 during the operation of the engine 2 in which the fuel pump 32 operates, particularly when the purge operation is executed, and the desorption performance of the canister 41 can be improved.

  In this embodiment, the piping for forming the cooling passage 51 and the piping for forming the purge passage are provided independently. However, the air from the air passage piping 44 is introduced into the cooling passage 51. On the other hand, a portion corresponding to the branch passage formed by the upstream and downstream cooling pipes 57a and 57b and the inner chamber so that the intake air passes from the cooling passage through the purge passage pipe 43 into the surge tank 23a. The cooling passage 51 in the portion 55 a may be formed as a passage in the case member 50.

  That is, as shown in FIG. 8A as a modified example of such a passage arrangement configuration, a notch that communicates the inside and outside of the inner cylinder wall 50b above the canister 41 is formed on the upper end side of the inner cylinder wall 50b. The portion 56n may be formed, and the air inlet 41e of the canister 41 may be opened in the upper space 50j. Further, as shown in FIG. 8 (b), a notch portion 56q is formed on the lower end side of the inner cylinder wall portion 50b to communicate the inside and outside of the inner cylinder wall portion 50b below the canister 41, and the purge gas of the canister 41 The outlet 41g may be opened in the lower space 50k.

  Further, as shown in FIG. 9A, the separation wall 50c that divides the inside of the case member 50 into the divided cylindrical inner chamber portions 55a and 55b is formed into a pair of quadrant cylinders. It may be divided (becomes a plurality of pairs of separation walls 50c between the outer cylinder wall 50a and the inner cylinder wall 50b). That is, the number of separation walls 50c is arbitrary.

  Further, the plurality of passage walls 50e, 50f having the cooling passage 51 folded in the inner chamber portion 55a are not limited to those extending in the vertical direction, and are shown in any direction deviating from the vertical direction, for example, as shown in FIG. Thus, the shape may extend in the horizontal direction.

  In each of the above-described embodiments, when a warning generation state that warns of a decrease in the remaining amount of fuel occurs, the vehicle stops under the warning state when it is determined that the temperature of the canister 41 is higher than the outside air temperature. The cooling control valve 56 is opened during the traveling period until the canister 41 is cooled by the cooling air passing through the cooling passage 51. The actual start of refueling is performed, for example, for detecting the remaining amount. This is detected by a sensor such as Sender Gauge 49, and it is judged from the history information such as the remaining value at the time of refueling whether or not there is a high probability of refueling although no warning is generated. When such a possibility arises, it is conceivable that the cooling control valve 56 is opened during the traveling period from the time point until the vehicle stops.

  Further, it is detected that a lid opening operation for opening the openable fuel lid 39 covering the cap 37b of the fuel filler port 37a is performed, or the opening of the fuel lid 39 or the fuel filler cap 37b is detected. In other words, after detecting that it is just before the start of refueling, other air pressure sources other than the engine 2 and other devices such as a compressor are used in combination to introduce cooling air into the cooling passage 51 (refueling). (Including the case of using in combination with the previous air cooling). Of course, it is conceivable to grasp from some other sensor information indicating that the probability of refueling is high.

  As described above, the evaporative fuel processing apparatus according to the present invention can cool the fuel in the canister and the fuel tank in a timely manner using the intake air of the internal combustion engine, and suppresses the temperature rise of the canister so that the fuel adsorption performance The temperature of the canister can be sufficiently lowered during refueling in order to increase fuel consumption and suppress the diffusion of fuel vapor during refueling. Therefore, the present invention is useful for an evaporated fuel processing apparatus, particularly an evaporated fuel processing apparatus in which the temperature of an adsorber connected to a fuel tank is adjusted to improve the performance of the adsorber.

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine (internal combustion engine), 3 ... Fuel supply mechanism, 4 ... Fuel purge system, 21 ... Injector, 22 ... Delivery pipe, 23a ... Surge tank, 23b ... Intake passage, 31 ... Fuel tank, 32 ... Fuel pump 36 ... Pressure regulator (relief valve, pressure reducing valve), 37 ... Oil supply pipe, 39 ... Fuel lid, 41 ... Canister (adsorber), 41a ... Canister case, 41b ... Adsorbent, 41c ... Outer wall, 41c1 , 41c2 ... Cooling wall surface portion, 41e ... Air introduction port, 41g ... Purge gas outlet, 42 ... Purge mechanism, 43b ... Canister side purge piping, 44 ... Air passage piping, 44b ... Canister side air piping, 45 ... Purge control mechanism 46 ... VSV for purge (flow rate control unit), 47 ... ECU (flow rate control unit), 48 ... Canister temperature sensor , 49 ... Sender gauge (remaining amount detection part), 50 ... Case member, 50a ... Outer cylinder wall part, 50b ... Inner cylinder wall part, 50c ... Separation wall (a pair of separation walls), 50e, 50f ... Passage wall, 51 ... cooling passage, 51p ... closeable passage section, 52 ... fuel storage chamber, 55a, 55b ... inner chamber portion, 55h ... communication port, 56,56C ... cooling control valve (flow rate control unit), 56A ... upstream flow rate control Valve (flow rate control unit), 56B ... downstream flow rate control valve (flow rate control unit), 57a ... upstream cooling pipe, 57b ... downstream cooling pipe, 58 ... adsorber temperature adjustment mechanism, 66 ... outside air temperature sensor , 67 ... Pressure sensor, 76 ... Reduction valve, 77 ... Fuel recirculation mechanism

Claims (7)

An adsorber attached to the fuel tank and adsorbing the evaporated fuel generated in the fuel tank;
An evaporative fuel processing apparatus comprising: a purge mechanism for performing a purge operation for sucking air for desorbing fuel from the adsorber and a purge gas containing fuel desorbed from the adsorber into an intake pipe of an internal combustion engine; There,
An adsorber temperature adjustment mechanism is provided that exposes the adsorber in a cooling passage through which intake air sucked into the internal combustion engine passes, and can cool the adsorber when the intake air flows in the cooling passage. An evaporative fuel processing apparatus characterized by the above.   The adsorber temperature adjustment mechanism causes the intake air to flow through the cooling passage when the temperature of the adsorber is higher than the outside air temperature, and the suction in the cooling passage when the temperature of the adsorber is lower than the outside air temperature. The evaporative fuel processing apparatus according to claim 1, further comprising a flow rate control unit that restricts an air flow.   The flow rate control unit includes an upstream flow rate control valve capable of controlling a flow rate of the intake air in an upstream side passage portion upstream of the adsorber in the cooling passage, and a downstream side of the adsorber in the cooling passage. A downstream flow rate control valve capable of controlling the flow rate of the intake air at a downstream passage portion on the side, and the upstream side condition is that the temperature of the adsorber is lower than the outside air temperature. The evaporated fuel according to claim 2, wherein the opening degree of the flow rate control valve is reduced, and the opening degree of the downstream side flow rate control valve is reduced under a reduced opening degree state of the upstream side flow rate control valve. Processing equipment.   The flow rate control unit is preset with a pressure of the cooling passage between the upstream flow rate control valve and the downstream flow rate control valve under the reduced opening state of the upstream flow rate control valve. The evaporated fuel processing apparatus according to claim 3, wherein the degree of opening of the downstream flow rate control valve is controlled so as to maintain the negative pressure state.   In the flow control unit, the pressure of the cooling passage between the upstream flow control valve and the downstream flow control valve is preset in the closed state of the upstream flow control valve. The evaporated fuel processing apparatus according to claim 4, wherein when the threshold pressure is reached, the downstream flow rate control valve is closed. A fuel pump that pumps up and discharges fuel in the fuel tank and supplies the fuel to the internal combustion engine, and a fuel recirculation mechanism that can recirculate the fuel discharged from the fuel pump toward the adsorber. And installed inside
A case member for housing the adsorber is installed in the fuel tank;
The case member is formed with the cooling passage and a fuel storage chamber into which the recirculated fuel from the fuel recirculation mechanism flows,
The evaporative fuel processing apparatus according to any one of claims 1 to 5, wherein the adsorber is exposed in the fuel storage chamber so that heat can be transferred.   The fuel recirculation mechanism recirculates the fuel discharged from the fuel pump into the fuel storage chamber before or when the purge operation is performed by the purge mechanism. Evaporative fuel processing equipment.

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