JP2021181756A - Catalyst activity control device for vehicle - Google Patents

Abstract

To securely generate evaporated fuel and securely perform catalyst activity control even in a situation where generation of evaporated fuel in a fuel tank is insufficient.SOLUTION: A catalyst activity control device 10 for a vehicle includes: a fuel tank 34 storing liquid fuel to be supplied to an engine 12; a catalyst 38 provided in an exhaust passage 16 of the engine 12 and purifying exhaust gas; communication passages 152, 154 communicating the fuel tank 34 with an upstream part of the catalyst 38 in the exhaust passage 16; an evaporated fuel storage part 86 provided between the communication passages 152, 154 and storing evaporated fuel generated in the fuel tank 34; an air supply pump 63 supplying the evaporated fuel in the evaporated fuel storage part 86 to an upstream side of the catalyst 38; and a second purge valve 62 for communication/blockage of the communication passage 154. The catalyst activity control device also includes heating means 64 heating the liquid fuel in the fuel tank 34. Evaporated fuel is generated in the fuel tank 34 by using the heating means 64 and the evaporated fuel is stored in the evaporated fuel storage part 86.SELECTED DRAWING: Figure 1

Description

The techniques disclosed herein relate to a vehicle catalytic activity controller. More specifically, the present invention relates to a catalyst activity control device for supplying evaporative fuel generated in a fuel tank to a catalyst for purifying vehicle exhaust gas to activate the catalyst.

A catalyst is provided in the exhaust passage of the engine of a vehicle such as an automobile to purify the exhaust gas of the engine. Conventionally, various measures for activating this catalyst have been proposed. In particular, the catalyst atmosphere may become lean when the hybrid (HV) vehicle is intermittently stopped, when the engine is restarted during idling stop in a normal vehicle, or after the fuel cut is completed during fuel cut running. In this case, nitrogen oxides (NOx) may be discharged when the engine is restarted or after the fuel cut is completed. Various improvement measures for this have been proposed.

For example, there is a countermeasure proposal as in Patent Document 1 below. The proposal is to enable catalytic activity control, which activates the catalyst with a purge gas from the canister, even during a cold start. The control for this is to send the purge gas to the exhaust passage on the upstream side of the catalyst by a pump in the inactive state of the catalyst, and promote the activity by the oxidation reaction of the fuel in the catalyst. In this control, after the catalytic activity, the intake passage is purged by the suction negative pressure, but the catalytic activity is controlled so that a predetermined amount of evaporated fuel used in the catalytic activity control remains in the canister. It is designed to limit the purging from later canisters. Therefore, when the purge gas concentration drops to a predetermined value, the purge is controlled to be stopped.

Japanese Unexamined Patent Publication No. 2003-328737

However, in the case of the above-mentioned catalytic activity control, the storage of the evaporative fuel in the canister stores the evaporative fuel (vaporized fuel) generated in the situation where the liquid fuel in the fuel tank is placed. Therefore, there is no particular problem in the situation where a large amount of evaporative fuel is generated, but there is a concern that the catalytic activity control becomes insufficient in the situation where the generation of evaporative fuel is insufficient.

Therefore, the problem to be solved by the technique disclosed in the present specification is devised in view of the above-mentioned points, and even in a situation where the generation of evaporative fuel in the fuel tank is insufficient. , The evaporative fuel is surely generated, and the catalytic activity is surely controlled.

In order to solve the above problems, the vehicle catalytic activity control device disclosed in the present specification takes the following means.

The first means are an engine, a fuel tank for storing liquid fuel supplied to the engine, a catalyst provided in the exhaust passage of the engine to purify the exhaust gas from the engine, and the fuel tank and the exhaust passage. A communication passage that communicates with the upstream portion of the catalyst in the above, an evaporative fuel storage unit that is provided in the communication passage and stores the evaporative fuel generated in the fuel tank, and the evaporative fuel in the evaporative fuel storage unit are exhausted. A vehicle catalyst having a pump supplied upstream of the catalyst in the passage and an on-off valve provided between the evaporated fuel storage portion on the communication passage and the exhaust passage to communicate / shut off the communication passage. The activity control device is provided with a heating means for heating the liquid fuel in the fuel tank, the heating means generates evaporative fuel in the fuel tank, and stores the evaporative fuel in the evaporative fuel storage unit. It is a vehicle catalytic activity control device.

According to the first means, the heating means for heating the liquid fuel in the fuel tank can generate the evaporative fuel in the fuel tank and always sufficiently store the evaporative fuel in the evaporative fuel storage unit. As a result, the evaporated fuel is reliably supplied from the fuel storage portion to the upstream portion of the catalyst in the exhaust passage, and the catalyst can be reliably activated. Therefore, it is possible to activate the catalyst at the time of restarting the engine at the time of intermittent stop of the vehicle or idling stop, or at the time of returning after the fuel cut running, and it is possible to surely prevent or suppress the emission of so-called emissions. can.

The second means is the catalyst activity control device for the vehicle of the first means described above, and the heating means is configured to heat the fuel tank by utilizing the heat of the exhaust passage of the engine. It is a catalytic activity control device of.

According to the second means, the heating means utilizes the heat of the exhaust passage of the engine. According to this, since no electrical means is required, there is a so-called energy saving effect.

The third means is the vehicle catalyst activity control device of the second means described above, and the position where the heat of the exhaust passage of the engine in the heating means is used is the catalyst installation position of the vehicle. It is an activity control device.

According to the third means, the position where the heat of the exhaust passage of the engine as the heating means is used is the position where the catalyst is installed. Since the position of the catalyst is the position where the heat is highest in the exhaust passage, the heat of the exhaust passage can be effectively utilized to heat the fuel tank.

The fourth means is a vehicle catalytic activity control device for any of the above-mentioned first means to the third means, and further, the evaporated fuel storage section is provided with evaporation in the vaporized fuel storage section. It is a vehicle catalytic activity control device provided with a concentration sensor for detecting the fuel concentration and driving the heating means when the evaporative fuel concentration is less than a predetermined value.

According to the fourth means, the evaporated fuel storage unit is provided with a concentration sensor for detecting the evaporation fuel concentration in the evaporation fuel storage unit, and when the evaporation fuel concentration in the evaporation fuel storage unit is less than a predetermined value, Controls to drive the heating means. As a result, the heating means is not unnecessarily driven, and the fuel tank is not unnecessarily heated.

The fifth means is a catalyst activity control device for the vehicle of any of the above-mentioned first means to the fourth means, and the evaporated fuel storage unit supplies the evaporated fuel to the intake passage of the engine. It is a catalyst activity control device for vehicles, which is also used as a canister provided for fuel control.

According to the fifth means, the evaporative fuel storage unit is also used as a canister. This makes it possible to simplify the catalytic activity control device.

The sixth means is a catalyst activity control device for the vehicle of any of the above-mentioned first means to the fourth means, and the evaporated fuel storage unit supplies the evaporated fuel to the intake passage of the engine. It is a catalyst activity control device for vehicles, which is set separately from the canister provided for this purpose.

According to the sixth means, the canister is installed only for the evaporative fuel processing apparatus that processes the evaporative fuel generated in the conventional fuel tank. Therefore, the blowing performance of the canister when the vehicle is stopped is not adversely affected.

According to the vehicle catalytic activity control device disclosed in the present specification, even in a situation where the evaporative fuel is insufficiently generated in the fuel tank, the evaporative fuel is surely generated and the catalytic activity is surely controlled. be able to.

It is an engine system block diagram which shows 1st Embodiment of the catalyst activity control device of a vehicle. It is a flowchart which shows the control flow of the heating pipe route in the catalyst activity control of 1st Embodiment. It is a flowchart which shows the control flow of the catalytic activity path in the catalytic activity control of 1st Embodiment. It is an engine system block diagram which shows the 2nd Embodiment of the catalyst activity control device of a vehicle.

Hereinafter, embodiments of the vehicle catalytic activity control device, which is the technique disclosed in the present specification, will be described with reference to the drawings. In addition, the explanation of the direction display such as left-right, up-down, etc. in the description of this specification indicates the direction in the illustrated state, and unless otherwise specified, indicates the direction of the state in which the catalyst activity control device is mounted on a vehicle or the like. It's not a thing.

(First Embodiment)
First, the first embodiment will be described. The first embodiment is shown in FIG. FIG. 1 shows the overall configuration of an engine system including a vehicle catalytic activity control device 10. In the first embodiment shown in FIG. 1, the catalytically active path 90 characterized by the present embodiment and the evaporative fuel treatment path 40 for treating the evaporative fuel of the fuel tank 34 conventionally provided are separate systems. It is a system configuration that is arranged.

(Engine 12)
As shown in FIG. 1, an intake passage 14 and an exhaust passage 16 are arranged in the engine 12. An intake valve 20 is provided at the inlet of the cylinder 18 of the engine 12 in the intake passage 14, and the air-fuel mixture of fuel and air is taken into the cylinder 18 from the intake passage 14 by opening and closing the intake valve 20. An exhaust valve 22 is provided in the exhaust passage 16 at the outlet of the cylinder 18 of the engine 12, and the exhaust gas is discharged from the combustion chamber 24 of the cylinder 18 to the exhaust passage 16 by opening and closing the valve. A spark plug 26 is provided in the combustion chamber 24 of the cylinder 18, and the ignition of the spark plug 26 causes the air-fuel mixture to burn and generate power for the engine 12.

(Intake passage 14)
The intake passage 14 is provided with an air cleaner 28, a throttle valve 30, and a fuel injection valve (injector) 32. The air cleaner 28 is arranged at the inlet of the intake passage 14 and includes an air filter element to clean the air sucked into the engine 12.

The throttle valve 30 is a valve that controls the amount of air taken into the engine 12, and is usually controlled by operating an accelerator pedal (not shown). The fuel injection valve 32 injects fuel from the fuel tank 34 into the intake passage 14, forms an air-fuel mixture with the air sucked from the air cleaner 28, and introduces the fuel into the cylinder 18 of the engine 12 from the intake valve 20. A fuel pump 36 is provided in the fuel tank 34, and the liquid fuel stored in the fuel tank 34 is pumped up and supplied to the fuel injection valve 32 from the fuel supply path 35.

(Exhaust passage 16 and catalyst 38)
The exhaust passage 16 is a passage for discharging the exhaust gas from the engine 12 to the atmosphere, and a catalyst 38 for purifying the exhaust gas is arranged in the exhaust passage 16. The catalyst 38 of the present embodiment is a three-way catalyst that oxidizes carbon monoxide CO and hydrocarbon HC, which are three harmful components in the exhaust gas, and reduces nitrogen oxide NOx to cause harmless carbon dioxide CO _2. , Steam H ₂ O, and nitrogen N ₂ .

The air-fuel mixture introduced into the combustion chamber 24 of the engine 12 is ignited and combusted by the spark plug 26. The combustion gas is discharged from the exhaust valve 22 to the exhaust passage 16 as exhaust gas. At the time of this discharge, the catalyst 38 purifies the exhaust gas. A silencer (not shown) is usually arranged downstream of the catalyst 38, and then released into the atmosphere.

(Evaporated fuel processing path 40 and canister 42)
In addition to the fuel supply path 35 to the fuel injection valve 32 described above, an evaporative fuel processing path 40 for processing the evaporative fuel generated in the fuel tank 34 is set between the fuel tank 34 and the intake passage 14. There is. The evaporative fuel processing path 40 includes a canister 42. The canister 42 is configured by filling a closed container with an adsorbent 44 such as activated carbon. The canister 42 is provided with a tank port 46, a purge port 48, and an atmospheric port 50.

The tank port 46 is connected to the fuel tank 34 by the first evaporative fuel introduction pipe 52, and the evaporative fuel (vaporized fuel) of the fuel tank 34 is introduced into the canister 42. Then, it is adsorbed and collected on the adsorbent 44. The purge port 48 is connected to the intake passage 14 by the first purge pipe 54, and the evaporated fuel collected in the adsorbent 44 of the canister 42 is desorbed and supplied to the intake passage 14 under predetermined conditions.

A first purge valve 60 is provided in the first purge pipe 54, and is controlled based on a control command from an ECU (electronic control unit) 84, which will be described later, to supply evaporative fuel from the canister 42 to the intake passage 14. The supply position to the intake passage 14 by the first purge pipe 54 is set to a position between the throttle valve 30 and the fuel injection valve 32.

The atmospheric port 50 of the canister 42 is an introduction port for taking in fresh air to the canister 42 when supplying evaporative fuel from the purge port 48 to the intake passage 14.

(Evaporated fuel reservoir 86 of the catalytically active path 90)
Next, the catalytic activity path 90 of the catalytic activity control device 10 characterized by the present embodiment will be described. The catalyst active path 90 is a path for supplying the evaporated fuel (vaporized fuel) generated in the fuel tank 34 to the upstream position of the catalyst 38 in the exhaust passage 16. As shown in FIG. 1, the catalytically active path 90 includes an evaporative fuel storage unit 86. The evaporative fuel storage unit 86 has the same configuration as the canister 42 in the evaporative fuel treatment path 40 described above, and the evaporative fuel storage unit 86 is configured by filling a closed container with an adsorbent 144 such as activated carbon. It has a tank port 146, a purge port 148, and an atmospheric port 150.

The tank port 146 of the evaporative fuel storage unit 86 is connected to the fuel tank 34 by a second evaporative fuel introduction pipe 152, and the evaporative fuel (vaporized fuel) of the fuel tank 34 is introduced into the evaporative fuel storage unit 86. Then, it is adsorbed and collected on the adsorbent 144. The purge port 148 is connected to the exhaust passage 16 by the second purge pipe 154, and the evaporated fuel collected in the adsorbent 44 of the evaporated fuel storage unit 86 is desorbed and supplied to the exhaust passage 16 under predetermined conditions. do. Therefore, the second evaporative fuel introduction pipe 152 and the second purge pipe 154 in the present embodiment correspond to the "communication passage connecting the fuel tank and the upstream portion of the catalyst in the exhaust passage" in the above-mentioned means of the present technology. do.

The second purge pipe 154 is provided with a second purge valve 62 and an air supply pump 63, and is controlled based on a control command from an ECU (electronic control unit) 84, which will be described later, from the evaporative fuel storage unit 86 to the exhaust passage 16. Supply evaporative fuel to. The second purge valve 62 is an on-off valve that communicates and shuts off the second purge pipe 154. The air supply pump 63 is a pump that takes in and supplies air in order to supply the evaporated fuel of the evaporated fuel storage unit 86 toward the exhaust passage 16 in the communicating state of the second purge valve 62. The supply position to the exhaust passage 16 by the second purge pipe 154 is an upstream position where the catalyst 38 is arranged.

The atmosphere port 150 of the evaporative fuel storage unit 86 is an introduction port for taking in fresh air to the evaporative fuel storage unit 86 when supplying evaporative fuel from the purge port 148 to the exhaust passage 16.

(Heating means 64)
Next, the heating means 64 of the catalytic activity control device 10 characterized by this embodiment will be described. As shown in FIG. 1, the heating means 64 of the present embodiment is provided in the fuel tank 34. The heating means 64 of the present embodiment is a method of heating the fuel tank 34 by indirectly utilizing the heat of the exhaust gas of the exhaust passage 16.

In the heating means 64 of the present embodiment, a heating unit 66 is arranged so as to cover the periphery of the fuel tank 34, and the fuel tank 34 is heated by the heating unit 66. In the present embodiment, the range of the bottom surface portion and the lower half portion of the side surface portion of the fuel tank 34 is surrounded as the heating portion 66. This surrounding range is appropriately set according to the position where the fuel tank 34 is installed and peripheral devices. Further, the heating unit 66 in FIG. 1 is schematically shown and is shown as a configuration that surrounds the lower portion range of the fuel tank 34, but it may be a configuration that can heat the fuel tank 34.

In the present embodiment, the position of the heat source unit 92 supplied to the heating unit 66 is the position of the catalyst 38 in the exhaust passage 16. In the present embodiment, a heat source portion 92 is formed on the outer peripheral portion of the catalyst 38 so as to surround the catalyst 38, and a heat source is formed in the heat source portion 92 by the radiant heat of the catalyst 38. The configuration of the heat source unit 92 is formed as a configuration that surrounds the entire catalyst 38 or a configuration that surrounds a part of the catalyst. The position of the heat source portion 92 is set to the position of the catalyst 38 because the exhaust gas heat is the highest in the exhaust passage 16. Therefore, heat can be obtained most efficiently.

(Heating piping path 68)
The heating unit 66 that heats the fuel tank 34 and the heat source unit 92 formed at the position of the catalyst 38 in the exhaust passage 16 are connected by a heating pipe path 68, and the heat of the heat source unit 92 is transferred to the heating unit 66. It is supposed to be supplied. A heating pump 69 is installed in the heating pipe path 68, and operates according to a control command from the ECU (electronic control unit) 84. In the present embodiment, the heating pump 69 is operated when the generation of evaporative fuel by the liquid fuel in the fuel tank 34 is insufficient. As a result, the fuel tank 34 is heated, and the generation of evaporative fuel in the fuel tank 34 is promoted.

The heating means 64 of the first embodiment described above is performed by utilizing the heat of the exhaust passage 16 of the engine 12, and is not a means of using electric heat, so that there is a so-called energy saving effect.

(ECU (Electronic Control Unit) 84)
Each device of the present embodiment described above, that is, each control of the catalyst activity control device 10, the fuel supply path 35, the evaporated fuel processing path 40, and the like is performed by the ECU (electronic control device) 84. The catalytic activity control device 10 is performed by controlling the catalytic activity path 90 and the heating piping path 68. Therefore, various input signals are taken into the ECU 84.

(Input to ECU 84)
An airflow sensor 70 and a throttle sensor 72 are installed in the intake passage 14. The air flow sensor 70 detects the amount of intake air in the intake passage 14. The throttle sensor 72 detects the opening degree of the throttle valve 30. An A / F sensor 74 is installed in the exhaust passage 16. The A / F sensor detects the ratio of air to fuel in the exhaust gas.

The cooling water temperature sensor 78 and the crank angle sensor 80 of the engine 12 are installed in the engine 12. The cooling water temperature sensor 78 detects the cooling water temperature of the engine 12. The crank angle sensor 80 detects the crank angle of the crankshaft of the engine 12.

A fuel remaining amount sensor 76 is installed in the fuel tank 34. The fuel remaining amount sensor 76 detects the remaining amount of fuel in the fuel tank 34 and gives an alarm.

A concentration sensor 82 is installed in the evaporative fuel storage unit 86. The concentration sensor 82 detects the concentration of the evaporated fuel (purge gas) in the evaporated fuel storage unit 86.

(Output from ECU 84)
The ECU (electronic control unit) 84 receives the signals from the above sensors, performs control for operating the following devices, and outputs an output signal for that purpose. Each device receives this output signal and operates. The device operated based on the output signal from the ECU 84 will be described below.

The fuel injection valve 32 of the intake passage 14 operates the injection timing, injection amount, and the like. The ignition timing of the spark plug 26 of the engine 12 is operated. The first purge valve 60 of the first purge pipe 54 is operated to open and close the first purge valve 60. Similarly, the second purge valve 62 of the second purge pipe 154 is operated to open and close the second purge valve 62. Further, the air supply pump 63 provided in the second purge pipe 154 also operates in the same manner as the second purge valve 62.

(Aim of control)
By the way, as mentioned in the background technology, in recent automobiles and other vehicles, in order to reduce fuel consumption, engine intermittent stop control is used for hybrid (HV) vehicles, idling stop control or fuel cut is used for ordinary automobiles and other vehicles. It may be driven. At the time of restarting the engine or at the end of fuel cut in this control, the atmosphere of the catalyst installed in the exhaust passage 16 may become lean, and NOx may be discharged at the time of restarting. This is due to insufficient control of catalytic activity. Therefore, in the present embodiment, sufficient evaporative fuel (vaporized fuel) is sent to the catalyst 38 to ensure reliable control of catalytic activity. ..

Therefore, in the present embodiment, the liquid fuel in the fuel tank 34 is evaporated and vaporized by using the exhaust heat of the exhaust gas of the exhaust passage 16 to heat the fuel tank 34, and the vaporized fuel is evaporated fuel. It is stored in the storage unit 86, and in the above-mentioned state, the vaporized fuel stored in the evaporated fuel storage unit 86 is sent to the catalyst 38 to control the amount of oxygen in the catalyst 38 and suppress NOx exhaust. ..

(Control flow)
2 and 3 show a basic control flowchart for controlling the above contents. FIG. 2 shows a control flowchart of the heating pipe path 68, and FIG. 3 shows a control flowchart of the catalytic activity path 90.

(Control flow of heating piping path 68)
First. This will be described based on the control flowchart of the heating pipe path 68 shown in FIG. Start in step S101, and confirm the IG-ON determination (ignition ON determination) in step S102. That is, it is confirmed whether or not the engine 12 is in the operating state. Then, when the engine 12 is in the non-operating state and is "No", this control is terminated (step S107). When the engine 12 is in the operating state and "Yes", the process proceeds to the next step S103.

In step S103, the concentration sensor 82 is used to measure the amount of vapor (evaporated fuel amount) in the evaporated fuel storage unit 86. Then, in step S104, the measured vapor amount and the target vapor amount are compared. When the amount of vapor in the evaporated fuel storage unit 86 is the same as or less than the target amount of vapor, that is, when it is "Yes", the process proceeds to the next step S105.

In step S105, the heating pump 69 of the heating pipe path 68 is driven to supply the heat acquired by the heat source unit 92 at the position of the catalyst 38 in the exhaust passage 16 to the heating unit 66. Then, the fuel tank 34 is heated by the heat supplied to the heating unit 66 to vaporize the liquid fuel in the fuel tank 34 and supply it to the evaporated fuel storage unit 86 as an evaporative fuel for storage. As a result, sufficient evaporative vaporized fuel is stored in the evaporative fuel storage unit 86.

In step S104, when the amount of vapor in the vaporized fuel storage portion 86 is larger than the target amount of vapor, that is, “No”, the process proceeds to step S106, and the heating pump 69 of the heating piping path 68 is stopped. As a result, the heating means 64 is not unnecessarily driven, and the fuel tank 34 is prevented from being unnecessarily heated. In that state, the process shifts to the control of the control flowchart of the catalytic activity path 90 shown in FIG.

(Control flow of catalytic activity path 90)
Next, the control flowchart of the catalytically active path 90 shown in FIG. 3 will be described. A second purge valve 62 and an air supply pump 63 are set in the catalytic activity path 90, and both 62 and 63 are controlled. The control of the catalytic activity path 90 shown in FIG. 3 is performed as a continuation from the stopped state of the heating pump 69 in step S106 shown in FIG.

In the stopped state of the heating pump 69 in S106 of FIG. 2, the process proceeds to step S108. First, in step S108, it is determined whether or not the fuel cut time by the fuel injection valve 32 is equal to or longer than a certain level.

When the determination in step S108 is "No", that is, when the fuel cut time has not elapsed for a certain period or more, the process proceeds to step S109, and it is determined whether or not the engine has returned from the idling stop.

Then, when the determination in step S109 is "No", that is, when the engine is not in the state after returning from the idling stop, the process proceeds to step S110, and it is determined whether or not the engine is intermittently started.

When the determination in step S110 is "No", the process proceeds to S112, the second purge valve 62 of the catalytically active path 90 is closed, and the air supply pump 63 is not driven. Therefore, the evaporative fuel stored in the evaporative fuel storage unit 86 is not supplied to the exhaust passage 16. That is, when all of steps S108, S109, and S110 are in the "No" state, the control of the exhaust gas is not a problem, and therefore, the supply of the evaporated fuel to the catalyst 38 of the exhaust passage 16 is not particularly required. Is.

Next, if any of the above steps S108, S109, and S110 is "Yes", the process proceeds to step S111. That is, when the fuel cut time is equal to or longer than a certain level, the engine is in the state after returning from the idling stop, or the engine is in the state after intermittent starting, the process proceeds to step S111.

In step S111, the second purge valve 62 of the catalytically active path 90 is opened, and the air supply pump 63 is driven. As a result, the evaporated fuel stored in the evaporated fuel storage unit 86 is supplied upstream of the catalyst 38 in the exhaust passage 16 by the second purge valve 62 and the air supply pump 63, and the catalyst 38 is activated.

The supply to the catalyst 38 in the exhaust passage 16 by the second purge valve 62 and the air supply pump 63 in step S111 is performed for a certain period of time. After a lapse of a certain period of time, the process proceeds to step S112, and in step S112, the second purge valve 62 is closed and the air supply pump is stopped to stop the supply. After that, the process proceeds to step S113, and the control is terminated.

Note that each determination of steps S108, S109, and S110 is a control flow in which the step of the function is omitted when the engine 12 does not have the function.

In the above steps S108, S109, and S110, any of the states where the fuel cut time is equal to or longer than a certain level, the state after returning from the idling stop, or the state after the intermittent start of the engine is the catalyst. It is a condition that requires activation. As described above, in the present embodiment, the catalyst 38 can be enriched and NOx can be reduced by sending the evaporative fuel (vaporized fuel) to the upstream position of the catalyst 38 in the exhaust passage 16. In addition, the increase in fuel after fuel cutting can be reduced, and fuel consumption can also be suppressed.

Further, in the first embodiment described above, the catalyst activity control device 10 characterized by the technique of the present disclosure and the evaporative fuel processing path 40 for processing the evaporative fuel of the fuel tank 34 conventionally provided are separate systems. It is said to be arranged. As a result, the evaporative fuel processing path 40 can be configured to function as before, and does not adversely affect the blow-by performance of the canister 42 when the vehicle is stopped.

(Second Embodiment)
Next, the second embodiment will be described. The second embodiment is shown in FIG. The second embodiment is configured by using the canister 42 and the evaporative fuel storage unit 86 of the first embodiment in combination. That is, the canister 42 is provided with the function of the evaporated fuel storage unit 86 in the first embodiment. Therefore, the components corresponding to the first embodiment are designated by the same reference numerals. The component parts common to the canister 42 and the evaporated fuel storage unit 86 are indicated by the reference numerals of the canister 42.

In the second embodiment shown in FIG. 4, the purge port 48 of the canister 42 is connected to the first purge pipe 54 of the evaporative fuel processing path 40 and the second purge pipe 154 of the catalytically active path 90 via the common purge pipe 58. It is branched and piped. The subsequent piping configuration is the same as that of the first embodiment. The concentration sensor 82 provided in the evaporated fuel storage unit 86 in the first embodiment is provided in the canister 42 in the second embodiment.

As described above, the second embodiment is a configuration in which the canister 42 has the function of the evaporative fuel storage unit 86, and the other configurations are the same. Therefore, detailed description of the other configurations will be omitted. Further, the basic control of the second embodiment is also omitted because it is the same as that of the first embodiment described above. According to the second embodiment, since the canister 42 has the function of the evaporative fuel storage unit 86, the configuration can be simplified.

(Third Embodiment)
Next, the third embodiment will be described. Although the illustration of the third embodiment is omitted, it is a modified embodiment of the first embodiment shown in FIG. As for the configuration of the third embodiment, in the configuration of the first embodiment shown in FIG. 1, first, the coupling of the first evaporative fuel introduction pipe 52 and the second evaporative fuel introduction pipe 152 to the fuel tank 34 is collectively combined into one. As the evaporative fuel introduction pipe, this one evaporative fuel introduction pipe is connected to the fuel tank 34. A three-way valve is arranged at a branch point between the one evaporative fuel introduction pipe coupled to the fuel tank 34 and the first evaporative fuel introduction pipe 52 and the second evaporative fuel introduction pipe 152.

In the third embodiment, according to the above configuration, when the fuel tank 34 is heated, the connection between the fuel tank 34 and the canister 42 is cut off by the three-way valve, and the evaporated fuel flows only to the evaporated fuel storage unit 86 to the canister 42. Is to prevent it from flowing.

(Fourth Embodiment)
Next, the fourth embodiment will be described. Although the illustration of the fourth embodiment is omitted, the fourth embodiment is also a modified embodiment of the first embodiment shown in FIG. The configuration of the fourth embodiment is a configuration in which control valves are arranged in each of the first fuel introduction pipe 52 and the second fuel introduction pipe 152 in the configuration of the first embodiment shown in FIG.

In the fourth embodiment, according to the above configuration, the control valves arranged in each of the first fuel introduction pipe 52 and the second fuel introduction pipe 152 are controlled, and when the fuel tank 34 is heated, the fuel tank 34 and the canister 42 are controlled. The communication state with the fuel tank 34 is cut off, and the fuel tank 34 and the evaporated fuel storage unit 86 are brought into a communication state. As a result, the evaporative fuel in the fuel tank 34 is controlled so as to flow only to the evaporative fuel storage unit 86 and not to the canister 42.

(Other embodiments)
The technique disclosed in the present specification is not limited to the above-described embodiment, and various modifications can be made.

For example, the heating means 64 of the fuel tank 34 is a method of utilizing the heat of the exhaust passage 16 in the above embodiment, but may be a means of electrically heating.

Further, in the method of utilizing the heat of the exhaust passage 16 in the heating means 64, the position of the heat source portion 92 is the position of the catalyst 38 of the exhaust passage 16, but it may be the position of another exhaust passage 16.

Further, the air supply pump 63 provided in the second purge pipe 154 of the catalytic activity path 90 can also be set as an air pump at the position of the atmospheric port 150 of the evaporated fuel storage unit 86 in the first embodiment. Similarly, in the second embodiment, it can be set as an air pump at the position of the atmospheric port 50 of the canister 42.

10 Catalyst activation controller 12 Engine 14 Intake passage 16 Exhaust passage 18 Cylinder 20 Intake valve 22 Exhaust valve 24 Combustion chamber 26 Ignition plug 28 Air cleaner 30 Throttle valve 32 Fuel injection valve 34 Fuel tank 35 Fuel supply path 36 Fuel pump 38 Catalyst 40 Evaporation Fuel processing route 42 Canister 44 Adsorbent 46 Tank port 48 Purge port 50 Atmospheric port 52 1st evaporative fuel introduction pipe 54 1st purge pipe 58 Common purge pipe 60 1st purge valve 62 2nd purge valve 63 Air supply pump 64 Heating means 66 Heating Part 68 Heating piping route 69 Heating pump 70 Airflow sensor 72 Throttle sensor 74 A / F sensor 76 Fuel level sensor 78 Cooling water temperature sensor 80 Crank angle sensor 82 Concentration sensor 84 ECU (electronic control device)
86 Evaporated fuel storage 90 Catalyst active path 92 Heat source 144 Adsorbent 146 Tank port 148 Purge port 150 Atmospheric port 152 Second evaporated fuel introduction pipe 154 Second purge pipe

Claims (6)

With the engine
A fuel tank that stores the liquid fuel supplied to the engine, and
A catalyst provided in the exhaust passage of the engine to purify the exhaust gas from the engine,
A communication passage connecting the fuel tank and the upstream portion of the catalyst in the exhaust passage,
An evaporative fuel storage unit provided in the communication passage and storing the evaporative fuel generated in the fuel tank,
A pump that supplies the evaporated fuel in the evaporated fuel reservoir upstream of the catalyst in the exhaust passage,
An on-off valve provided between the evaporative fuel storage section and the exhaust passage on the communication passage to communicate / shut off the communication passage.
Is a vehicle catalytic activity control device,
A heating means for heating the liquid fuel in the fuel tank is provided.
A vehicle catalytic activity control device that generates evaporative fuel in the fuel tank by the heating means and stores the evaporative fuel in the evaporative fuel storage unit. The vehicle catalytic activity control device according to claim 1.
The heating means is a catalyst activity control device for a vehicle, which is configured to heat the fuel tank by utilizing the heat of the exhaust passage of the engine. The vehicle catalytic activity control device according to claim 2.
The position where the heat of the exhaust passage of the engine in the heating means is used is the position where the catalyst is installed, which is the catalyst activity control device for the vehicle. The vehicle catalytic activity control device according to any one of claims 1 to 3.
Further, the evaporative fuel storage unit is provided with a concentration sensor for detecting the evaporative fuel concentration in the evaporative fuel storage unit, and drives the heating means when the evaporative fuel concentration is less than a predetermined value. .. The vehicle catalytic activity control device according to any one of claims 1 to 4.
The evaporative fuel storage unit is a vehicle catalytic activity control device that is also used as a canister provided for supplying evaporative fuel to the intake passage of the engine. The vehicle catalytic activity control device according to any one of claims 1 to 4.
The evaporative fuel storage unit is a vehicle catalytic activity control device set separately from a canister provided for supplying evaporative fuel to the intake passage of the engine.

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