JP2020084935A - vehicle - Google Patents

Abstract

To secure an opportunity to execute purge processing for supplying, to a suction pipe, evaporated fuel gas generated in a fuel tank.SOLUTION: A vehicle comprises an engine that has a supercharger and can operate intermittently, an evaporated fuel treatment device that purges evaporated fuel gas generated in a fuel tank into a suction pipe of the engine by opening a valve, and a controller that controls the valve so that purging is executed while the engine is running and the supercharger is not operating. The controller does not intermittently stop the engine when a ratio of a purging execution time to an engine operation time is equal to or less than a predetermined ratio.SELECTED DRAWING: Figure 3

Description

The present invention relates to a vehicle including an engine having a supercharger and an evaporated fuel processing device.

Conventionally, as a vehicle of this type, an engine having a supercharger and an evaporated fuel processing device for purging evaporated fuel gas generated in a fuel tank for storing fuel to be supplied to the engine into an intake path of the engine through a purge path. And the like are proposed (for example, refer to Patent Document 1). A canister that adsorbs the evaporated fuel gas is arranged in the purge path, and a control valve is arranged in the purge path between the canister and the intake path. Further, the purge path extending from the control valve to the intake path is bifurcated, and is connected to the intake path upstream and downstream of the supercharger. In this vehicle, the pump is arranged in the purge path between the canister and the control valve, and when performing the purge while the supercharger is operating, by driving the pump to pump the evaporated fuel gas, Evaporative fuel gas is mainly supplied to the intake path on the upstream side of the supercharger.

JP, 2018-17172, A

However, in the above-described vehicle, when the evaporative fuel processing device is not provided with a pump or the pump has a low pumping capacity, if the intake pipe becomes a positive pressure due to the operation of the supercharger, the intake passage will be opened even if the control valve is opened. It becomes difficult to supply (purge) the evaporated fuel gas to the.

A vehicle of the present invention is provided with an engine having a supercharger and an evaporated fuel processing device, and its main purpose is to secure an opportunity to execute a purge process for supplying evaporated fuel gas generated in a fuel tank to an intake pipe. And

The vehicle of the present invention adopts the following means in order to achieve the above-mentioned main object.

The vehicle of the present invention is
An engine that has a supercharger and is capable of intermittent operation,
A purge path connecting a fuel tank for storing fuel supplied to the engine and an intake pipe of the engine, a canister provided in the purge path, and a purge path provided between the intake pipe and the canister in the purge path. And a vaporized fuel processing device for purging the vaporized fuel gas generated in the fuel tank into the intake pipe of the engine by opening the valve,
A controller for controlling the valve such that the purge is performed while the engine is running and the supercharger is not operating;
A vehicle comprising:
The control device does not intermittently stop the engine when the ratio of the execution time of the purge to the operating time of the engine is equal to or less than a predetermined ratio,
That is the summary.

The control device for a vehicle according to the present invention controls the valve so that the purge is executed while the engine is running and the supercharger is not operating. Then, when the ratio of the purge execution time to the engine operation time is equal to or less than the predetermined ratio, the engine is not intermittently stopped. As a result, when the purging execution time is insufficient, the engine operation is not stopped even when the vehicle is stopped, etc., and therefore the purging execution opportunity in the situation where the supercharger is not operating is significantly increased. You can As a result, the purging can be performed at an appropriate frequency, and the evaporated fuel gas can be prevented from excessively accumulating in the canister.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 as one Example of this invention. It is a block diagram which shows the outline of a structure of the engine 22. 6 is a flowchart showing an example of a forced purge control routine executed by the engine ECU 24 of the embodiment.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a schematic diagram showing a schematic configuration of a hybrid vehicle 20 as an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a schematic configuration of an engine 22.

As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter, "HVECU"). 70).

The engine 22 is configured as an internal combustion engine that outputs hydrocarbon-based fuel, such as gasoline or light oil, stored in the fuel tank 150 by driving the fuel pump 152 to output power. As shown in FIG. 2, the engine 22 sucks the air cleaned by the air cleaner 122 into the intake pipe 125 through the throttle valve 124 and the fuel from the fuel tank 150 through the fuel injection valve 126 and is sucked. The air and fuel are mixed, and this mixture is sucked into the combustion chamber through the intake valve 128, explosively burned by electric sparks from the spark plug 130, and the reciprocating motion of the piston 132 pushed down by the energy is crankshaft. 26 into a rotary motion. Exhaust gas from the engine 22 is discharged to the outside air through a purification catalyst (three-way catalyst) (not shown) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

Further, the engine 22 includes a turbo-type supercharger (so-called turbocharger) 140 that supercharges by using the energy of exhaust gas. The supercharger 140 includes a compressor 142 provided in the intake pipe 125, a turbine 144 provided in the exhaust pipe 133, a connecting shaft 146 connecting the compressor 142 and the turbine 144, and an upstream side of the turbine 144 in the exhaust pipe 133. And a waste gate valve 135 provided in the bypass pipe 134 that connects the downstream side and the downstream side. In the supercharger 140, by adjusting the opening degree of the waste gate valve 135, the distribution ratio between the amount of exhaust flowing through the bypass pipe 134 and the amount of exhaust flowing through the turbine 144 is adjusted. As a result, the rotational driving force of the turbine 144 is adjusted, the amount of compressed air by the compressor 142 is adjusted, and the supercharging pressure (intake pressure) of the engine 22 is adjusted.

Further, the engine 22 also includes an evaporated fuel processing device 160 for purging the evaporated fuel generated in the fuel tank 150 to the intake pipe 125 side. The evaporated fuel processing device 160 includes a canister 164 that is filled with an adsorbent such as activated carbon that adsorbs evaporated fuel from the fuel tank 150, a communication passage 162 that connects the fuel tank 150 and the canister 164, a canister 164 and intake air. A purge passage 166 connecting the pipe 125 and a purge control valve 168 arranged in the purge passage 166 are provided. An air introduction pipe (not shown) is connected to the canister 164. The evaporated fuel processing device 160 adjusts the flow rate of gas containing evaporated fuel (hereinafter referred to as purge gas) by adjusting the opening degree of the purge control valve 168 and supplies (purges) the gas to the intake pipe 125 side. The engine 22 can thus suck the mixture of air, purge gas, and fuel from the fuel injection valve 126 into the combustion chamber.

The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. .. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 from an input port. The signals input to the engine ECU 24 include the crank angle θcr from the crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22, the intake air amount Qa from the air flow meter 171 attached to the intake pipe 125, The throttle opening TH from the throttle valve position sensor 172 that detects the position of the throttle valve 124, and the intake pressure Pin from the pressure sensor 173 that detects the pressure in the intake pipe 125 are included. In addition, the air-fuel ratio A/F from the air-fuel ratio sensor 174 attached to the exhaust pipe 133, the purge control valve opening PV from the opening sensor 175 that detects the opening of the purge control valve 168, and the like can be given.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through the output port. The signals output from the engine ECU 24 include a drive control signal to the throttle motor 123 for adjusting the position of the throttle valve 124, a drive control signal to the fuel injection valve 126, and a drive control to an ignition coil integrated with the igniter. Signals are included. Further, a drive control signal to the fuel pump 152 that supplies the fuel in the fuel tank 150 to the fuel injection valve 126, a control signal to an actuator that adjusts the opening degree of the waste gate valve 135 of the supercharger 140, and a purge control valve 168. A control signal to an actuator for adjusting the opening is also included.

The engine ECU 24 is connected to the HVECU 70 via a communication port, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data regarding the operating state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 calculates the rotation speed of the crankshaft 26, that is, the rotation speed Ne based on the crank angle θcr from the crank position sensor 23.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of the planetary gear 30 is connected to the rotor of the motor MG1. To the ring gear of the planetary gear 30, a drive shaft 36 connected to drive wheels 39a and 39b via an axle 38 and a differential gear 37 is connected. The crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

The motor MG1 is configured as, for example, a synchronous generator-motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and its rotor is connected to the drive shaft 36 via a reduction gear (not shown). The inverters 41 and 42 are connected to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by an electronic control unit for motor (hereinafter referred to as “motor ECU”) 40.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input/output port, and a communication port. .. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via an input port. The signal input to the motor ECU 40 flows to, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect rotational positions of rotors of the motors MG1 and MG2, and phases of the motors MG1 and MG2. A phase current from a current sensor that detects a current may be used. From the motor ECU 40, switching control signals to switching elements (not shown) of the inverters 41 and 42 are output via output ports. The motor ECU 40 is connected to the HVECU 70 via a communication port, drives and controls the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data regarding the driving states of the motors MG1 and MG2 to the HVECU 70 as necessary. Motor ECU 40 calculates rotation speeds Nm1 and Nm2 of motors MG1 and MG2 based on rotation positions θm1 and θm2 of rotors of motors MG1 and MG2 from rotation position detection sensors 43 and 44.

The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the inverters 41 and 42 via a power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via an input port. As the signal input to the battery ECU 52, for example, the battery voltage VB from the voltage sensor 51a installed between the terminals of the battery 50, the battery current IB from the current sensor 51b attached to the output terminal of the battery 50, the battery The battery temperature TB from the temperature sensor 51c attached to the battery 50 may be used. The battery ECU 52 is connected to the HVECU 70 via a communication port, and outputs data regarding the state of the battery 50 to the HVECU 70 as necessary. The battery ECU 52 calculates the charge ratio SOC based on the integrated value of the battery current IB from the current sensor 51b. The storage ratio SOC is the battery 5
It is the ratio of the capacity of the electric power that can be discharged from the battery 50 to the total capacity of 0. The battery ECU 52 also calculates input/output limits Win and Wout that are the maximum allowable electric power that can be charged/discharged from the battery 50 based on the charge ratio SOC and the battery temperature TB.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input/output port, and a communication port. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81. Further, an accelerator opening Acc from an accelerator pedal position sensor 84 for detecting the amount of depression of the accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 for detecting the amount of depression of the brake pedal 85, and a vehicle speed sensor 88. The vehicle speed V can also be mentioned. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

The hybrid vehicle 20 of the embodiment thus configured travels in any of a plurality of travel modes including a hybrid travel (HV travel) mode and an electric travel (EV travel) mode. Here, the HV traveling mode is a mode in which the engine 22 is driven while traveling with the power from the engine 22 and the power from the motors MG1 and MG2. The EV travel mode is a mode in which the vehicle travels by the power from the motor MG2 without operating the engine 22.

Further, in the hybrid vehicle 20 of the embodiment, it is monitored whether or not the purge execution condition for purging the evaporated fuel adsorbed by the canister 164 is satisfied, and when the purge execution condition is satisfied, the evaporated fuel is purged from the canister 164. A purge process is executed to open the purge control valve 168 so that the intake pipe 125 is supplied with the intake air through the passage 166. Here, the purge execution condition includes a condition based on the cooling water temperature of the engine 22 and the state of the canister 164, the engine 22 being in operation, and the supercharger 140 not operating. This is because, when the supercharger 140 is operating, the intake pipe 125 has a positive pressure, and therefore the evaporated fuel is not supplied to the intake pipe 125 side even if the purge control valve 168 is opened.

Next, the operation of the hybrid vehicle 20 of the embodiment thus configured will be described. In particular, the operation of the purging process will be described. FIG. 3 is a flowchart showing an example of the forced purge control routine executed by the engine ECU 24 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every several msec) after the vehicle is started.

When the forced purge control routine is executed, the CPU of the HVECU 70 first determines whether or not the forced purge control execution flag Fp is 0 (step S100). The forced purge control execution flag Fp is a flag that indicates whether or not forced purge control, which will be described later, is being executed. The value 1 indicates that it is being executed, and the value 0 indicates that it is not being executed.

If it is determined that the forced purge control execution flag Fp is 0, then it is determined whether the engine 22 is in operation (step S110). If it is determined that the engine 22 is not operating, the process proceeds to step S160. On the other hand, when it is determined that the engine 22 is in operation, the engine operation counter Ce is incremented by 1 (step S120), and whether or not the supercharger 140 is in a non-operating state (unsupercharged state) (step S120). (S130), it is determined whether the purge control valve 168 is open (step S140). Here, in the determination of step S130, since the intake pipe 125 has a positive pressure when the supercharger 140 operates, the intake pressure Pin (the positive pressure is a positive value) detected by the pressure sensor 173 is greater than 0. Can be performed by determining whether or not The determination in step S140 can be performed by determining whether the purge control valve opening PV detected by the purge control valve opening sensor 175 is larger than the value 0. When it is determined that the supercharger 140 is in the non-operating state (non-supercharging state) and the purge control valve 168 is open, it is determined that the purge is being performed, and the purge execution counter Cp is set to 1 Only is incremented (step S150) and the process proceeds to step S160.

Next, it is determined whether or not the determination execution condition for determining the necessity of the forced purge control is satisfied (step S160). The determination execution condition is satisfied, for example, when the ignition switch 80 is turned on and the system is started and the engine 22 is started along with the start of the system, or when the warm-up operation of the engine 22 is completed. It can be done. If it is determined that the determination execution condition is not satisfied, the forced purge control routine ends. On the other hand, when it is determined that the determination execution condition is satisfied, the value of the purge execution counter Cp is divided by the engine operation counter Ce to calculate the purge execution ratio α that is the ratio of the purge execution time to the operation time of the engine 22. Then (step S170), it is determined whether the purge execution ratio α is equal to or less than the threshold value αref (step S180). The threshold value αref is a threshold value for determining whether the execution of the purge is insufficient and an excessive amount of evaporated fuel may remain in the canister 164.

If it is determined that the purge execution ratio α is not less than or equal to the threshold value αref and is greater than the threshold value αref, it is determined that the purge execution is not insufficient, and the forced purge control routine ends. On the other hand, when it is determined that the purge execution ratio α is less than or equal to the threshold value αref, it is determined that the execution of the purge is insufficient, and the intermittent operation of the engine 22 is prohibited (the idling stop is prohibited) (step S190) and forced. The value 1 is set to the purge control execution flag Fp (step S200), and the forced purge control routine is ended.

Here, in the present embodiment, the engine 22 has the supercharger 140, and when the supercharger 140 is in the operating state (supercharging state), the pressure in the intake pipe 125 is a positive pressure. In this state, even if the purge control valve 168 is opened, the evaporated fuel in the canister 164 is not supplied to the intake pipe 125, so the purging is executed only when the supercharger 140 is in the inactive state. On the other hand, the purging is promoted because the pressure in the intake pipe 125 increases as a negative pressure when the operating state of the engine 22 is in the idling operating state. However, in the hybrid vehicle 20 of the present embodiment, the engine 22 is intermittently stopped. As a result, the idling operation is rarely performed, and purging is likely to be insufficient. Therefore, in this embodiment, the intermittent stop of the engine 22 is prohibited when the purge execution ratio α is equal to or less than the threshold value αref. As a result, the operating state of the engine 22 can be forcibly set to an operating state in which purging is likely to be promoted (for example, an idling operating state), so that the opportunity of purging can be significantly increased and the lack of purging can be eliminated. it can.

When the value 1 is set in the forced purge control execution flag Fp, the purge is completed because the forced purge control execution flag Fp is determined to be the value 1 in step S100 when the forced purge control routine is executed next time. It is determined whether or not (step S210). The determination in step S210 can be made based on, for example, the integrated value of the purge amount calculated based on the operating state of the engine 22 (intake pressure Pin) and the opening degree of the purge control valve 168. If it is determined that the purge is not completed, the forced purge control routine is once terminated, and if it is determined that the purge is completed, the intermittent stop of the engine 22 is permitted (step S220), and the forced purge control execution flag Fp is set to 0. Is set (step S230). Then, both the engine operation counter Ce and the purge execution counter Cp are reset to the value 0 (step S240), and the forced purge control routine ends.

In the hybrid vehicle 20 of the present embodiment described above, the purge control valve 168 is controlled so that the purge is executed while the engine 22 is operating and the supercharger 140 is not operating. When the ratio of the purge execution time to the operation time of the engine 22 (purge execution ratio α) is less than or equal to the threshold value αref, the intermittent stop of the engine 22 is prohibited. As a result, when the purging execution time is insufficient, the engine operation is not stopped even when the vehicle is stopped, for example, and therefore the purging execution opportunity is greatly increased in the situation where the supercharger 140 is not operating. be able to. As a result, the purge can be executed at an appropriate frequency, and the evaporated fuel gas can be prevented from staying excessively in the canister 164.

In the embodiment, the present invention is applied to the hybrid vehicle 20 that travels using the power from the engine 22 and the power from the motor MG2. However, only the power from the engine is used without a traveling motor. It may be applied to a vehicle that travels in such a way. That is, the vehicle may be any vehicle that includes an engine with a supercharger that has an idling stop function.

Correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the supercharger 140 corresponds to a “supercharger”, the engine 22 corresponds to an “engine”, the fuel tank 150 corresponds to a “fuel tank”, and the communication passage 162 and the purge passage 166 “purge”. The canister 164 corresponds to a “canister”, the purge control valve 168 corresponds to a “valve”, and the engine ECU 24 corresponds to a “control device”.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the vehicle manufacturing industry.

20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38 axle, 39a, 39b drive wheel, 40 motor Electronic control unit (motor ECU), 41, 42 inverter, 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 54 power line, 70 hybrid electronic control unit, 81 shift lever, 82 shift position sensor, 83 accelerator Pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 122 air cleaner, 123 throttle motor, 124 throttle valve, 125 intake pipe, 126 fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 133 exhaust pipe, 134 bypass pipe, 135 waste gate valve, 140 supercharger, 142 compressor, 144 turbine, 146 connecting shaft, 150 fuel tank, 152 fuel pump, 160 evaporative fuel processing device, 162 communication passage, 164 Canister, 166 purge passage, 168 purge control valve, 171 air flow meter, 172 throttle valve position sensor, 173 pressure sensor, 174 air-fuel ratio sensor, 175 purge control valve opening sensor, MG1, MG2 motor.

Claims (1)

An engine that has a supercharger and is capable of intermittent operation,
A purge path connecting a fuel tank for storing fuel supplied to the engine and an intake pipe of the engine, a canister provided in the purge path, and a purge path provided between the intake pipe and the canister in the purge path. And a vaporized fuel processing device for purging the vaporized fuel gas generated in the fuel tank into the intake pipe of the engine by opening the valve,
A controller for controlling the valve such that the purge is performed while the engine is running and the supercharger is not operating;
A vehicle comprising:
The control device does not intermittently stop the engine when the ratio of the execution time of the purge to the operating time of the engine is equal to or less than a predetermined ratio,
vehicle.

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