JP2012171520A - Control device of electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an electric vehicle for appropriately giving an instruction to drive or stop an engine 18 in order to reduce emission caused by driving the engine 18, in a range extender electric vehicle including a rotating machine 12 serving as an in-vehicle main machine, a battery 14, a rotating machine 16 servicing as an in-vehicle auxiliary machine, the engine 18 and a catalyst 46.SOLUTION: When it is determined that the amount of electric power stored in the battery 14 is less than a first prescribed amount, power generation mode processing is performed to drive the engine 18 in order to charge the battery 14. When it is determined that the temperature of the catalyst 46 is lower than a warm-up preparation temperature which is higher than an activation temperature, and the amount of electric power stored in the battery 14 is smaller than a second prescribed amount which is larger than the first prescribed amount, catalyst warm-up mode processing that drives the engine 18 is performed in order to give precedence to the supply of exhaust heat to the catalyst 46. Here, the second prescribed amount is set to be larger as the temperature of the catalyst 46 is lowered.

Description

  The present invention includes only a main machine rotating machine as an in-vehicle main machine and serves as a power supply source for the main machine rotating machine, an auxiliary machine rotating machine for charging the battery, and a power supply source for the auxiliary machine rotating machine. The present invention relates to a control device for an electric vehicle applied to an electric vehicle including an engine and an exhaust purification catalyst provided on an exhaust passage of the engine.

  Conventionally, as a vehicle, a hybrid vehicle including an engine and a rotating machine as an in-vehicle main machine is known as can be seen in Patent Document 1 below. Specifically, in this vehicle, when the vehicle is traveling in the suburbs, processing for setting the control center value of the charge amount for charging / discharging the battery higher than that in the city region is performed. As a result, emission generated as the engine is driven is reduced.

JP 2009-279989 A

  By the way, for the purpose of further reducing the emission and extending the travelable distance of the vehicle, a generator that includes only a rotating machine that is driven by an in-vehicle battery as a power supply source as an in-vehicle main unit and that charges the battery, and this power generation Development of a so-called range extender vehicle (also referred to as a series hybrid vehicle), which is an electric vehicle provided with an engine serving as a power supply source for the machine and an exhaust purification catalyst provided on an exhaust passage of the engine, is in progress.

  Specifically, this vehicle basically travels using a rotating machine as a travel power source without driving an engine. On the other hand, when the amount of electricity stored in the battery is reduced by driving a rotating machine or driving an in-vehicle device (for example, an in-vehicle air conditioner) using the battery as a power supply source, Drive the engine.

  Here, in the said vehicle, it is requested | required to make the frequency which drives an engine for battery charging as low as possible from a viewpoint of reducing an emission. However, if the frequency at which the engine is driven decreases, the catalyst temperature tends to decrease due to a decrease in the frequency with which exhaust heat is supplied to the catalyst, and it may be difficult to maintain a high exhaust purification capability of the catalyst. In this case, when the engine is driven, there is a concern that the amount of emissions released into the atmosphere increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for an electric vehicle that can suppress an increase in emissions in the range extender electric vehicle.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention according to claim 1 is provided with only a main machine rotating machine as an in-vehicle main machine and a battery serving as a power supply source of the main machine rotating machine, an auxiliary machine rotating machine for charging the battery, and the auxiliary machine rotating machine Applied to an electric vehicle including an engine serving as a power supply source and an exhaust purification catalyst provided on an exhaust passage of the engine, and an object set through the temperature of the catalyst and instruction means operated by a user An execution request for a power generation mode process for driving the engine to generate power in the auxiliary rotating machine based on at least one of the information on the ground is predicted, and before the predicted execution request is generated, the auxiliary rotating machine The catalyst warm-up mode for warming up the catalyst by driving the engine in a state where the rotational energy of the output shaft of the engine transmitted to the engine is smaller than that during execution of the power generation mode process. Characterized in that it comprises a control means for executing the process.

  When the power generation mode process for driving the engine and generating power in the auxiliary rotating machine is performed, if the catalyst temperature is low, the exhaust gas purifying ability of the catalyst is reduced, so that it is released into the atmosphere as the engine is driven. There is a concern that emissions will increase.

  In this respect, in the above-described invention, the execution request for the power generation mode process is predicted based on at least one of the information on the catalyst temperature and the vehicle destination. That is, prior to the generation request for the power generation mode process or the request for execution of the power generation mode process, while grasping the exhaust gas purification capacity of the catalyst and the amount of battery charge required for traveling of the vehicle before reaching the destination, As a result, the latest timing at which the catalyst warm-up mode processing can be completed is predicted. Thus, before the predicted execution request is generated, the engine is driven with the rotational energy of the engine output shaft transmitted to the auxiliary machine rotating machine smaller than that during execution of the power generation mode process to warm up the catalyst. The catalyst warm-up mode process to be performed can be executed.

  According to such a configuration, since the amount of fuel for driving the auxiliary rotating machine can be reduced, the amount of fuel required for driving the engine can be reduced. For this reason, it is possible to suppress an increase in emission due to driving of the engine while the catalyst is warming up. After that, it is possible to suppress the occurrence of a situation in which the exhaust gas purification capability becomes low when the power generation mode process is executed. Therefore, according to the said invention, the increase in emission can be suppressed.

  According to a second aspect of the present invention, in the first aspect of the invention, the control means executes the power generation mode process when it is determined that the stored amount of the battery is less than a first specified amount. In the catalyst warm-up mode process, it is determined that the storage amount of the battery is less than a second specified amount that is greater than or equal to the first specified amount and higher than the first specified amount; When it is determined that the temperature of the catalyst is lower than a specified temperature, the process is a process of driving the engine.

  In the above invention, the power generation mode process is executed when it is determined that the charged amount of the battery is less than the first specified amount in order to avoid a situation where the charged amount of the battery is excessively insufficient. Here, when the engine is not driven under the situation where the main machine rotating machine is driven, the amount of electricity stored in the battery gradually decreases, and the temperature of the catalyst does not increase. For example, the temperature of the catalyst does not increase. In view of the transition of the amount of electricity stored and the temperature of the catalyst, even when the amount of electricity stored in the battery is equal to or higher than the first specified amount, it is close when the temperature of the catalyst is determined to be lower than the specified temperature. In the future, it is considered possible to predict that a request for execution of the power generation mode process will occur when the stored amount of the battery is less than the first specified amount.

  In view of this point, in the above-described invention, it is determined that the storage amount of the battery is equal to or more than the first specified amount and less than the second specified amount, and the temperature of the catalyst is determined to be less than the specified temperature. In this case, it is predicted that an execution request for the power generation mode process will occur in the near future, and the catalyst warm-up mode process is executed prior to the execution of the power generation mode process. According to such an invention, the catalyst warm-up mode process can be executed at an appropriate timing.

  According to a third aspect of the present invention, in the second aspect of the present invention, the specified temperature is a warm-up preparation temperature equal to or higher than an activation temperature of the catalyst.

  In the above invention, before the catalyst temperature is excessively below the activation temperature, exhaust heat is supplied to the catalyst by executing the catalyst warm-up mode process. Therefore, the catalyst temperature is kept high and the exhaust purification ability of the catalyst is kept high. can do. Thereby, an increase in emission can be suitably suppressed when the power generation mode process is executed.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the specified temperature is a warm-up preparation temperature equal to or higher than an activation temperature of the catalyst, and the second specified amount is determined by the temperature of the catalyst. The lower the value, the higher the value.

  The lower the temperature of the catalyst, the longer it takes to raise the temperature of the catalyst to a predetermined temperature by supplying exhaust heat. In view of this point, in the above-described invention, the catalyst warm-up mode process is performed when it is determined that the storage amount is less than the second specified amount in a situation where the temperature of the catalyst is determined to be lower than the warm-up preparation temperature. . Here, the second specified amount is set higher as the catalyst temperature is lower.

  According to such setting, when the catalyst warm-up mode process is completed, it is assumed that the charged amount of the battery does not become less than the first specified amount as soon as possible (the catalyst warm-up is performed before the generation request for the power generation mode process is generated). The catalyst warm-up mode process can be started so that the time for raising the temperature of the catalyst can be appropriately secured. As a result, the exhaust gas purification capacity of the catalyst can be maintained high while avoiding an excessive decrease in the amount of electricity stored in the battery.

  A fifth aspect of the invention is the spark ignition type of the invention according to any one of the first to fourth aspects, wherein the engine includes a spark plug that generates a discharge spark in a combustion chamber of the engine. The catalyst warm-up mode process is characterized in that the ignition timing by the spark plug is delayed from the time of execution of the power generation mode process.

  In the above invention, the exhaust temperature can be appropriately raised by delaying (retarding) the ignition timing, and the temperature of the catalyst can be quickly raised. Thereby, the increase in the emission at the time of execution of the catalyst warm-up mode process and the power generation mode process can be more suitably suppressed.

  The invention according to claim 6 is the invention according to any one of claims 2 to 5, wherein the control means determines that the power generation is performed when the storage amount of the battery is less than a first specified amount. The catalyst warm-up mode process is a mode process, wherein the battery charge amount is less than a second specified amount that is greater than or equal to the first specified amount and higher than the first specified amount. And when the temperature of the catalyst is determined to be lower than the warm-up preparation temperature equal to or higher than the activation temperature of the catalyst, the control means is a process for driving the engine. The execution of the catalyst warm-up mode process is continued until the temperature reaches a warm-up determination temperature higher than the warm-up preparation temperature, and then the process proceeds to the power generation mode process.

  In the above invention, the catalyst warm-up mode process is shifted to the power generation mode process in the above-described manner. For this reason, the temperature of the catalyst can be sufficiently higher than the activation temperature when the power generation mode process is executed, and an increase in emission can be suitably suppressed.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the control means determines that the power generation when the storage amount of the battery is less than a first specified amount. A predetermined threshold value that is to perform mode processing and that is assumed when the vehicle reaches the destination set via the instruction means, and that is stored in the battery less than the first specified amount In such a case, a process for prohibiting the execution of the power generation mode process is performed.

  When the amount of stored battery power required until the vehicle reaches the destination is sufficient, it is desirable not to execute the power generation mode process as much as possible from the viewpoint of suppressing an increase in emissions.

  In this regard, in the above-described invention, when the amount of power stored in the battery that is assumed when the vehicle reaches the destination is equal to or greater than a predetermined threshold value that is less than the first specified amount, a process that prohibits the execution of the power generation mode process is performed. To do. As a result, the vehicle can be driven without driving the engine, and as a result, an increase in emissions can be suitably suppressed.

  According to an eighth aspect of the present invention, in the invention according to any one of the seventh aspect, the information on the destination set through the instructing means is used until the set destination is reached. Based on the required power amount calculating means for calculating the amount of power required for the vehicle, the power amount calculated by the required power amount calculating means, and the charged amount of the battery, the setting is performed without executing the power generation mode process. And determining means for determining whether or not the vehicle is reachable at the destination, and the prohibiting process is determined to be reachable by the determining means as the instructing process. It is a process for prohibiting the execution of the power generation mode process.

  In the above invention, whether or not the vehicle can reach the destination without executing the power generation mode process based on the amount of electric power (required electric energy) required for the vehicle to reach the destination and the amount of power stored in the battery. Determine whether. If it is determined that the power generation mode is reachable, execution of the power generation mode process can be prohibited.

  The invention according to claim 9 is the in-vehicle navigation device according to claim 8, wherein the instruction means has a function of grasping a current position of the vehicle and a function of setting a destination of the vehicle by a user. The required power amount calculation means calculates the amount of power required by the vehicle based on a travel route from the current position grasped by the navigation device to the set destination.

  In the above-described invention, the calculation accuracy of the required power can be improved by using the travel route from the current position of the vehicle to the destination for calculating the required power.

  According to a tenth aspect of the present invention, in the invention according to the ninth aspect, the navigation device stores information relating to a charging location of the battery, and the setting is performed based on the stored information relating to the charging location. Release means for canceling prohibition of execution of the power generation mode process when it is determined that the charging place is not at the destination or when it is determined whether the charging place is at the set destination Is further provided.

  In the above invention, the prohibition of execution of the power generation mode process is canceled when there is no battery charging place at the destination or when it is unknown whether there is a battery charging place. For this reason, it is possible to avoid a situation in which the amount of power stored in the battery is excessively insufficient by restricting the charging of the battery by the prohibition process.

  The invention according to claim 11 is the invention according to any one of claims 1 to 10, wherein the vehicle is provided with a recovery means for recovering exhaust heat exhausted from the engine, and heating the vehicle interior. When it is determined that there is a request, the apparatus further includes a heating unit that drives the engine and performs heating using the exhaust heat recovered by the recovery unit.

  In the said invention, a vehicle interior can be heated appropriately using exhaust heat.

The system block diagram concerning one Embodiment. The flowchart which shows the procedure of the catalyst warm-up mode process and electric power generation mode process concerning one Embodiment. The time chart which shows an example of the catalyst warming-up mode process and electric power generation mode process concerning one Embodiment. The time chart which shows an example of the catalyst warming-up mode process and electric power generation mode process concerning one Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment embodying a control device according to the invention will be described with reference to the drawings.

  FIG. 1 shows a system configuration diagram according to the present embodiment.

  The illustrated vehicle 10 is a range extender electric vehicle that includes only a rotating machine 12 (hereinafter, main motor generator MG1) as an in-vehicle main machine. In addition, the vehicle 10 includes a battery 14 serving as a power supply source for the main motor generator MG1, a rotating machine 16 (hereinafter referred to as an auxiliary motor generator MG2) as an in-vehicle auxiliary machine, an engine 18, and an air conditioner (air conditioner). 20).

  The battery 14 is connected to the main motor generator MG1 and the auxiliary motor generator MG2 via an inverter (not shown), and stores stored energy for driving these motor generators. Further, the battery 14 is charged by power generation by the auxiliary motor generator MG2 or by an external charging facility (for example, a quick charger or a household power source) via a plug PG provided in the battery 14 or the like. The battery 14 supplies power to a low voltage battery (not shown) (for example, a 12V auxiliary battery) via a DC-DC converter (not shown).

  Main motor generator MG1 is driven by the supply of energy stored in battery 14. The drive energy generated by main motor generator MG1 is transmitted to drive wheels 24 via reduction mechanism 22 and the like. Main motor generator MG1 has a function of generating regenerative power when vehicle 10 is decelerated to charge battery 14.

  The cylinder head of the engine 18 is provided with an electromagnetically driven fuel injection valve 28 (in-cylinder injection valve) that directly injects fuel supplied from a vehicle fuel tank (not shown) into the combustion chamber 26. The cylinder head is provided with a spark plug 30, and a center electrode and a ground electrode provided at the tip of the spark plug 30 protrude into the combustion chamber 26.

  The fuel injection valve 28 is not limited to the in-cylinder injection valve, but may be, for example, a port injection valve that injects and supplies fuel to the intake passage 32 of the engine 18.

  In the present embodiment, the engine 18 is assumed to be a single cylinder. This simplifies the structure of the engine 18 to reduce costs, reduces the weight of the engine 18 to increase the mileage of the vehicle, reduces the displacement and reduces the noise generated by the engine 18, etc. It is intended.

  The intake passage 32 is provided with an intake pressure sensor 34 for detecting the pressure of intake air flowing through the passage. Further, the downstream side of the intake passage 32 is connected to the combustion chamber 26 of the engine 18. The intake port and the exhaust port of the engine 18 are opened and closed by the intake valve 36 and the exhaust valve 38, respectively.

  In such a configuration, an air-fuel mixture of the intake air introduced into the combustion chamber 26 from the intake passage 32 by opening the intake valve 36 and the fuel injected and supplied by the fuel injection valve 28 is ignited by the discharge spark of the spark plug 30. It is used for combustion. The energy generated by the combustion is taken out as rotational energy of the crankshaft 42 through the piston 40. The air-fuel mixture used for combustion is discharged into the exhaust passage 44 as exhaust gas by opening the exhaust valve 38.

  In the present embodiment, from the viewpoint of reducing the number of in-vehicle devices and reducing the cost, a crank angle sensor (for example, an electromagnetic pickup sensor) that directly detects the rotational angle position of the crankshaft 42 is provided near the crankshaft 42. : MPU sensor, magnetoresistive element type sensor: MRE sensor) are not provided.

  The exhaust passage 44 is provided with, in order from the upstream side, an exhaust purification catalyst (hereinafter referred to as catalyst 46) for purifying harmful components in the exhaust, and an evaporation section 48a of a heat recovery device 48 for recovering exhaust heat. ing.

  Specifically, the catalyst 46 can maintain a high exhaust purification capability when its temperature is equal to or higher than the activation temperature. Examples of the catalyst 46 include a three-way catalyst that purifies NOx, HC, and CO in the exhaust gas. The catalyst 46 is provided with a catalyst temperature sensor 50 for detecting the catalyst temperature.

  The heat recovery device 48 includes a circulation passage 48b as a fluid passage through which a working fluid (for example, ammonia and water) circulates by driving a pump (not shown). The evaporating part 48a as a heat absorbing part and the condensing part 48c as a heat radiating part are provided in the middle of the circulation passage 48b. Specifically, the working fluid flowing through the circulation passage 48b absorbs heat from the exhaust through heat exchange with the exhaust while passing through the evaporator 48a, and then radiates heat to the cooling water of the engine 18 in the condensing unit 48c. Thereby, the temperature of the cooling water can be raised, and the heat of the cooling water can be used for heating the passenger compartment by the heater core 52 described later.

  The air conditioner 20 includes an air passage 54 for supplying warm air or the like into the passenger compartment, a blower 56 (for example, a fan or a blower) that generates an air flow in the passage, and a heater core for heating the air flowing through the air passage 54. 52. Specifically, the heater core 52 is a member that heats air using the cooling water of the engine 18 as a heat source. The blower 56 is connected to the auxiliary battery and is driven using the battery as a power supply source.

  In such a configuration, the air blown by the blower 56 passes through the heater core 52 and is subjected to heat exchange so as to reach a desired temperature. Then, the heat-exchanged air is supplied to the vehicle interior from an unillustrated air outlet formed in the air passage 54, thereby heating the vehicle interior.

  The auxiliary motor generator MG2 has a function of generating electric power by being driven by the rotational energy of the crankshaft 42 and charging the battery 14, or applying initial rotation (motoring) to the crankshaft 42.

  Specifically, first, the charging function will be described. An electromagnetically driven clutch 58 is provided that places power between the crankshaft 42 and the auxiliary motor generator MG2 in a transmission state (ON state) or a cutoff state (OFF state). Under the condition that the clutch 58 is in the ON state, the battery 14 is charged by the power generation energy of the auxiliary motor generator MG2. Next, the motoring function will be described. Auxiliary motor generator MG2 is driven by the supply of stored energy from battery 14 to perform motoring under the situation where clutch 58 is turned on.

  The vehicle 10 is provided with a navigation device 60. The navigation device 60 has a function of grasping the current position of the vehicle 10 by a GPS signal or the like. The display unit 60a displays map information and the like, a user interface 60b operated by the user, map information, and charging of the battery 14 The storage unit 60c (memory) is configured to store information on the location and the location where the fuel is supplied to the in-vehicle fuel tank. Note that the information stored in the storage unit 60c is appropriately updated by communication with the outside.

  The electronic control unit (hereinafter referred to as ECU 62) is mainly composed of a microcomputer composed of a well-known CPU, ROM, RAM, and the like, each of which operates as a main motor generator MG1, an auxiliary motor generator MG2, an engine 18, an air conditioner 20, and the like. It is comprised as. The ECU 62 includes an air conditioning switch 64 that is operated by the user to indicate air conditioning by the air conditioner 20, a battery sensor 66 that detects the voltage and input / output current of the battery 14, the intake pressure sensor 34, and the catalyst temperature sensor 50. Etc. are input.

  Further, the ECU 62 and the navigation device 60 exchange information. Specifically, input information of the user through the user interface 60b, current position information of the vehicle 10, and the like are input to the ECU 62. On the other hand, information related to the result of processing performed by the ECU 62 is input to the navigation device 60.

  The ECU 62 executes various control programs stored in the ROM in response to the input, thereby driving the main motor generator MG1, the fuel injection control process by the fuel injection valve 28, and the air conditioner device 20. Air conditioning control processing is performed.

  The fuel injection control process will be described. First, based on the intake air amount calculated from the intake air pressure detected by the intake air pressure sensor 34 and the rotational speed of the crankshaft 42 (engine rotational speed), the fuel injection valve 28 Set the fuel injection amount command value. More specifically, the command value is set to increase as the intake air amount increases. Then, the fuel injection valve 28 is energized based on the set command value. As a result, fuel corresponding to the command value is injected from the fuel injection valve 28.

  Note that each of the motor generator, the engine 18, the air conditioner device 20, and the like is actually operated by each of different electronic control devices, but these electronic control devices are denoted as ECU 62 here.

  In particular, the ECU 62 performs power generation mode processing, catalyst warm-up mode processing, and heating mode processing.

  In the power generation mode process, the first specified amount S1 in which the amount of electricity stored in the battery 14 (the amount of electric power stored in the battery 14, hereinafter referred to as SOC) calculated from the output value of the battery sensor 66 is higher than the lower limit value S0 of the SOC. In the case where it is determined that the value is less than the value, the auxiliary motor generator MG2 is driven to charge the battery 14. Specifically, when engine 18 is driven and clutch 58 is turned on, the rotational energy of crankshaft 42 is transmitted to auxiliary motor generator MG2, which is driven. Thereby, battery 14 is charged by power generation of auxiliary motor generator MG2. The lower limit value S0 is the minimum SOC value that can maintain the reliability of the battery 14.

  In the catalyst warm-up mode process, when it is determined that the catalyst temperature calculated from the output value of the catalyst temperature sensor 50 is lower than the warm-up preparation temperature T2 higher than the activation temperature, prior to the execution of the power generation mode process, A state in which the rotational energy of the crankshaft 42 transmitted to the auxiliary motor generator MG2 is made smaller than that during execution of the power generation mode process (in other words, by reducing the driving torque of the auxiliary motor generator MG2, the auxiliary motor generator This is a process of driving the engine 18 in a state where the generated power of the MG2 is lower than when the power generation mode process is executed. This process is a process for promoting warm-up of the catalyst 46 and suppressing an increase in emissions when the power generation mode process is executed.

  Further, in the present embodiment, as the catalyst warm-up mode process, a process of delaying (retarding) the ignition timing by the spark plug 30 from the time of executing the power generation mode process is also performed.

  In the catalyst warm-up mode process, the requirement for reducing the rotational energy of the crankshaft 42 transmitted to the auxiliary motor generator MG2 is to suppress an increase in emissions during catalyst warm-up. That is, since the rotational energy of the crankshaft 42 to be supplied to the auxiliary motor generator MG2 is reduced, the amount of fuel injection from the fuel injection valve 28 required for driving the engine 18 during catalyst warm-up can be reduced. That is, the fuel injection amount from the fuel injection valve 28 when the catalyst warm-up mode process is executed can be reduced more than the fuel injection amount when the power generation mode process is executed. For this reason, an increase in emission during catalyst warm-up is suppressed.

  Further, the requirement to retard the ignition timing is to increase the exhaust gas temperature to promote the increase in the catalyst temperature and further suppress the increase in emission. Here, the increase in the catalyst temperature is promoted by the retard of the ignition timing because the energy taken to rotate the crankshaft 42 is reduced and the exhaust valve 38 is opened after the fuel combustion is started. This is because the time until the valve is shortened and the heat energy taken by the cylinder block of the engine 18 among the heat energy generated by the combustion is reduced.

  According to such a catalyst warm-up mode process, it is possible to shorten the period from the start of the warm-up of the catalyst 46 until the catalyst temperature becomes equal to or higher than the activation temperature, and to reduce the fuel injection amount during the catalyst warm-up. It is possible to suppress the increase in emission.

  Further, the heating mode process is a process of operating the air conditioner device 20 to drive the engine 18 and heat it using the exhaust heat recovered by the heat recovery device 48. Here, as the heating mode process, for example, a process similar to the catalyst warm-up mode process may be performed to increase the exhaust gas temperature.

  In addition, when the engine 18 is driven in each of the power generation mode process, the catalyst warm-up mode process, and the heating mode process, combustion is performed so that the engine rotation speed becomes a steady state while controlling the engine rotation speed to the target rotation speed. Control (fuel injection control by the fuel injection valve 28 and ignition control by the spark plug 30) is performed. Here, performing combustion control so that the engine rotational speed is in a steady state means performing combustion control so that the engine rotational speed is constant, or that the absolute value of the fluctuation amount of the engine rotational speed is a predetermined value or less. It means that combustion control is performed so that More specifically, the combustion control is performed so that the engine rotational speed and the target rotational speed coincide with each other, or the absolute value of the fluctuation amount that is the difference between the engine rotational speed and the target rotational speed is equal to or less than a predetermined value. That means.

  Incidentally, the reason why the engine 18 can be driven with the engine rotation speed set to the steady state is that the engine 18 is not used as an in-vehicle main unit, and therefore there are few restrictions on the setting of the driving state of the engine 18.

  The engine rotation speed may be calculated based on the time between timings when it is determined that the intake pressure detected by the intake pressure sensor 34 is equal to or lower than the specified pressure. More specifically, it may be calculated by dividing one combustion cycle (720 ° C. A) by the time between the timings. This calculation method is based on the fact that the timing at which the intake pressure becomes equal to or lower than the specified pressure appears once in one combustion cycle.

  Next, the procedure of the engine drive control process including the power generation mode process and the catalyst warm-up mode process according to the present embodiment will be described with reference to FIG. This process is repeatedly executed by the ECU 62, for example, at a predetermined cycle.

  In this series of processing, first, in step S10, it is determined whether or not a destination has already been set in the navigation device 60 via the user interface 60b.

  If it is determined in step S10 that the destination has already been set, the process proceeds to step S12, and it is determined whether there is a charging facility for the battery 14 at the set destination. Whether or not there is a charging facility for the battery 14 may be determined based on information regarding the charging location of the battery 14 stored in the storage unit 60c of the navigation device 60.

  If it is determined in step S12 that there is a charging facility for the battery 14, the process proceeds to step S14, where the vehicle is reached before reaching the destination based on the travel route from the current position to the destination that is grasped by the navigation device 60. Is calculated (required power amount PW). Here, required power amount PW includes the amount of power consumed by driving main motor generator MG1 and the amount of power consumed by driving an on-vehicle electric load such as air conditioner device 20. The required power amount PW may be calculated in consideration of the road gradient and traffic jam information in the travel route.

  In a succeeding step S16, it is determined whether or not the required power amount PW is smaller than a value obtained by subtracting the lower limit value S0 from the SOC of the battery 14. This process is a process for determining whether or not it is predicted that an execution request for the power generation mode process will occur before the vehicle reaches the destination. That is, it is a process for determining whether or not the vehicle can reach the destination without executing the power generation mode process.

  On the other hand, when it is determined that the destination is not set in the navigation device 60 (when a negative determination is made in step S10), or there is no charging facility for the battery 14 or there is a charging facility at the set destination When it is determined that it is unknown (when a negative determination is made in step S12), the process proceeds to step S18. In addition, even when it is determined that the vehicle cannot reach the destination without executing the power generation mode process (when a negative determination is made in step S16), the power generation mode process is permitted to be executed (the execution of the power generation mode process is prohibited). In step S18, the process proceeds to step S18. In this step S18, it is determined whether or not the SOC of the battery 14 is less than the first specified amount S1. This process is for determining whether or not there is a request for executing the power generation mode process.

  When an affirmative determination is made in step S18, the process proceeds to step S20 to execute power generation mode processing.

  On the other hand, if a negative determination is made in step S18, the process proceeds to step S22 to determine whether or not the catalyst temperature Tct is lower than the warm-up preparation temperature T2.

  When it is determined in step S22 that the catalyst temperature Tct is lower than the warm-up preparation temperature T2, the process proceeds to step S24, and the second specified amount S2 higher than the first specified amount S1 is set to be lower than the catalyst temperature Tct. Set as high as possible. Here, the lower the catalyst temperature Tct, the higher the second specified amount S2 is set. Step S34, which will be described later, is provided so as to ensure time for raising the catalyst temperature Tct to the warm-up determination temperature T3, which will be described later. This is for starting the catalyst warm-up mode process in FIG.

  That is, the lower the catalyst temperature Tct, the longer the time required to raise the catalyst temperature Tct to the warm-up determination temperature T3 by supplying exhaust heat. For this reason, it is assumed that the SOC of the battery does not become less than the first specified amount S1 when the catalyst temperature Tct is raised to the warm-up determination temperature T3 by setting the second specified amount S2 in the above aspect. Can be predicted as late as possible. As a result, the catalyst warm-up mode process can be started at an appropriate timing thereafter.

  In a succeeding step S26, it is determined whether or not the SOC of the battery 14 is less than the second specified amount S2.

  If an affirmative determination is made in step S16 or a negative determination is made in steps S22 and S26, the process proceeds to step S28 to determine whether there is a heating request. Here, whether there is no heating request may be determined based on, for example, whether the user has not instructed heating based on the output value of the air conditioning switch 64.

  If an affirmative determination is made in step S28, it is determined that there is no need to drive the engine 18, and a process of stopping the engine 18 is executed in step S30. Specifically, processing for stopping fuel injection from the fuel injection valve 28 and ignition by the spark plug 30 is executed.

  On the other hand, if an affirmative determination is made in step S26 or a negative determination is made in step S28, the process proceeds to step S32, where catalyst warm-up mode processing or heating mode processing is executed.

  Specifically, in a situation where the SOC of the battery 14 is determined to be less than the second specified amount S2, if the catalyst temperature Tct is determined to be less than the warm-up determination temperature T3, the catalyst temperature Tct is determined to be the warm-up determination temperature. The catalyst warm-up mode process is executed until T3 is reached. On the other hand, when it is determined that there is a heating request, a heating mode process is executed.

  In addition, when the process of step S20, S30, S32 is completed, this series of processes is once complete | finished.

  Incidentally, after the catalyst warm-up mode process is continued until the catalyst temperature Tct reaches the warm-up determination temperature T3, a process for shifting to the power generation mode process is performed. That is, the power generation mode process is executed in a state where the catalyst temperature Tct is sufficiently higher than the activation temperature T1.

  FIG. 3 shows an example of the catalyst warm-up mode process and the power generation mode process according to this embodiment. Specifically, FIG. 3 (a) shows the transition of the engine speed NE, FIG. 3 (b) shows the transition of the catalyst temperature Tct, FIG. 3 (c) shows the transition of the SOC of the battery 14, FIG. 3D shows the transition of the ignition timing. In FIG. 3D, “advance angle” indicates that the power generation mode process is executed, and “retard angle” indicates that the catalyst warm-up mode process is executed.

  In the example shown in the figure, at time t1, the power generation mode process is stopped, and EV driving for driving the vehicle 10 by the main motor generator MG1 is started with the engine 18 stopped. Thereafter, the catalyst temperature Tct gradually decreases, and the catalyst warm-up mode process is started when the catalyst temperature Tct decreases to the warm-up preparation temperature T2 at time t2. Thus, the catalyst warm-up mode process is continued until time t3 when the catalyst temperature Tct reaches the warm-up determination temperature T3. Thereafter, the process proceeds from the catalyst warm-up mode process to the power generation mode process. Thereby, compared with the case where the control logic in which the catalyst warm-up mode process is not executed prior to the execution of the power generation mode process (also indicated by a dotted line in the figure), the exhaust gas purification capacity of the catalyst 46 at the start of the power generation mode process is obtained. Can be made sufficiently high.

  Next, FIG. 4 shows an example of the catalyst warm-up mode process and the power generation mode process based on the required power amount PW according to the present embodiment. Specifically, FIG. 4A to FIG. 4C correspond to the previous FIG. 3A to FIG. 3C. In FIG. 4B, the transition of the required power amount PW is also shown.

  The illustrated example shows a case where the catalyst temperature Tct is excessively low, such as when the engine 18 is stopped for a certain period of time. Under such circumstances, a process for calculating the required power amount PW each time is started by setting a destination in the navigation device 60 at time t1. Then, at time t2 when the value obtained by subtracting the lower limit value S0 from the SOC of the battery 14 becomes equal to or less than the required power amount PW, the catalyst warm-up mode process is started prior to the execution of the power generation mode process (in FIG. 2 above). S16: NO → S18: NO → S22: YES → S24 → S26: YES → S32). Thereafter, at time t3 when it is determined by the catalyst warm-up mode process that the catalyst temperature Tct has reached the warm-up determination temperature T3, the process proceeds to the power generation mode process.

  As described above, in this embodiment, the catalyst warm-up mode process, the power generation mode process, and the engine stop process are appropriately selected and executed according to the catalyst temperature Tct and the required power amount PW, thereby avoiding deterioration of exhaust characteristics. Therefore, it is possible to appropriately instruct to drive or stop the engine 18.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When it is determined that the catalyst temperature Tct is lower than the warm-up preparation temperature T2 and it is determined that the SOC of the battery 14 is lower than the second specified amount S2, the catalyst warm-up mode process is executed. Here, the second specified amount S2 is set higher as the catalyst temperature Tct is lower. For this reason, time for raising the catalyst temperature Tct by the catalyst warm-up mode process can be secured. Thereby, the exhaust purification capacity of the catalyst can be maintained high while avoiding occurrence of a situation where the SOC of the battery 14 is excessively insufficient. Therefore, an increase in emission can be suitably suppressed.

  (2) As the catalyst warm-up mode process, a process for making the rotational energy of the crankshaft 42 transmitted to the auxiliary motor generator MG2 smaller than that at the time of the power generation mode process, and the ignition timing by the spark plug 30 in the power generation mode process A process of retarding the execution time was performed. Thereby, the increase in the emission during catalyst warm-up can be suppressed more suitably.

  (3) After the catalyst warm-up mode process is started, the catalyst warm-up mode process is continued until the catalyst temperature Tct reaches the warm-up determination temperature T3. After that, the process shifted to power generation mode processing. As a result, when the battery 14 is charged, the catalyst temperature Tct can be sufficiently higher than the activation temperature T1, and an increase in emission can be more suitably suppressed.

  (4) The required power amount PW was calculated each time based on the travel route from the current position of the vehicle 10 to the destination. Then, when it is determined that the required power amount PW is smaller than the value obtained by subtracting the lower limit value S0 from the SOC of the battery 14, processing for prohibiting execution of the power generation mode processing (processing for stopping the engine 18) is performed. Thereby, the vehicle 10 can be traveled without driving the engine 18 as much as possible, and the emission can be reduced together with the fuel consumption.

  (5) When it is determined that there is no charging place for the battery 14 at the destination, or when it is determined that there is no charging place for the battery 14 at the destination, the prohibition of execution of the power generation mode processing is canceled . Thereby, before the SOC of the battery 14 becomes excessively short, the battery 14 can be charged by the power generation mode process.

  (6) When it is determined that there is a heating request, a heating mode process is performed. Thereby, according to a user's request | requirement, a vehicle interior can be heated appropriately.

(Other embodiments)
The above embodiment may be modified as follows.

  In the above embodiment, the required power amount PW is smaller than the value obtained by subtracting the lower limit value S0 from the SOC of the battery 14 as to whether or not the vehicle 10 can reach the destination without executing the power generation mode process. However, the present invention is not limited to this. For example, instead of the lower limit value S0, determination may be made using a value that is higher than the lower limit value S0 and equal to or less than the first specified amount S1.

  The calculation method of the required power amount PW is not limited to the one exemplified in the above embodiment. For example, the calculation may be based on the distance between the current position and the destination, not limited to the travel route.

  The instruction means operated by the user to indicate information related to the destination is not limited to the navigation device 60. For example, it may be a portable device (for example, a mobile phone) that can be carried by the user. Even in this case, the required power amount PW is calculated based on the input information via the portable device by providing the ECU 62 with the current position and destination of the vehicle acquired via the portable device. be able to.

  -Information regarding the destination of a vehicle is not restricted to what was illustrated to the said embodiment. For example, it may be the planned travel distance of the vehicle. In this case, for example, the required power amount PW may be calculated based on the set scheduled travel distance, the assumed power amount (for example, a fixed value) required for the vehicle per unit travel distance, and the power consumption amount of the in-vehicle device. In this case, the navigation device 60 may not be provided, and a simple configuration instruction unit that can input only the planned travel distance may be employed.

  -The calculation method of the engine rotation speed is not limited to that exemplified in the above embodiment. For example, the crank angle sensor may be provided, and the engine speed may be calculated based on the output value of the sensor.

  -In above-mentioned embodiment, although catalyst temperature Tct was detected by the catalyst temperature sensor 50, it is not restricted to this. For example, the catalyst temperature Tct may be estimated by a process that estimates the catalyst temperature Tct, which is a well-known technique. Specifically, the process of estimating the catalyst temperature Tct includes, for example, an exhaust temperature sensor that detects the exhaust temperature upstream of the catalyst 46 in the exhaust passage 44, and a water temperature sensor that detects the temperature of the engine cooling water. Alternatively, a process for estimating the catalyst temperature Tct based on the detected value of the water temperature sensor can be considered. More specifically, first, an initial value of the catalyst temperature is calculated based on the engine coolant temperature when the engine is not driven and is in thermal equilibrium with the outside air. Then, in a situation where the engine is driven thereafter, the catalyst temperature may be estimated by calculating the temperature rise of the catalyst from the initial value based on the degree of increase in the engine coolant temperature.

  In the above embodiment, the control logic is adopted in which the catalyst warm-up mode process is continued until it is determined that the catalyst temperature Tct has increased to the warm-up determination temperature T3, and then the power generation mode process is shifted. Absent. For example, after it is determined that the catalyst temperature Tct has increased to the warm-up determination temperature T3 and the catalyst warm-up mode process is completed, the condition that the catalyst temperature Tct decreases to the activation temperature T1, and the SOC of the battery 14 is the first When the condition that the logical sum of the condition that it is less than the prescribed amount S1 is true is satisfied, a control logic that executes the power generation mode process may be employed. Even in this case, it is possible to prevent the SOC of the battery 14 from becoming excessively short while maintaining the exhaust purification capacity of the catalyst 46 as high as possible.

  In the above embodiment, the warm-up preparation temperature T2 is set to a temperature higher than the activation temperature of the catalyst 46, but is not limited thereto. For example, the warm-up preparation temperature T2 may be set to the same temperature as the activation temperature. Further, for example, the warm-up preparation temperature T2 may be set to a temperature lower than the activation temperature. Even in this case, since the exhaust gas purification capability of the catalyst 46 can be increased at the start of execution of the power generation mode process, an increase in emissions can be suppressed.

  -In the said embodiment, you may employ | adopt the control logic which transfers to step S26 after a negative judgment is made at step S16. In this case, the second specified amount S2 may be set as a fixed value slightly larger than the first specified amount S1. Thereby, the catalyst warm-up mode process can be executed before the generation request for the power generation mode process is generated.

  The catalyst warm-up mode process is not limited to that exemplified in the above embodiment. For example, the process may be such that the engine 18 is driven with the clutch 58 in the OFF state (the engine 18 is in a no-load state). As a result, fuel for driving auxiliary motor generator MG2 becomes unnecessary, so that an increase in emissions can be suppressed more suitably.

  -The combustion control method of the engine 18 is not limited to the one exemplified in the above embodiment. For example, a process of variably setting the target rotation speed by selecting one of a plurality of different rotation speeds may be executed. Specifically, for example, the target rotation speed may be set higher as the SOC of the battery 14 is lower in the power generation mode process or the catalyst temperature is lower in the catalyst warm-up mode process.

  In the above embodiment, the exhaust heat recovered by the heat recovery device 48 is supplied to the heater core 52 via the engine cooling water, but the present invention is not limited to this. For example, a configuration may be employed in which exhaust heat recovered by the heat recovery device 48 is directly supplied to the heater core 52 without using engine cooling water.

  The engine 18 is not limited to a single cylinder but may be a multiple cylinder, for example. Further, the engine 18 is not limited to a spark ignition type internal combustion engine such as a gasoline engine, but may be a compression ignition type internal combustion engine, for example. Here, as the compression ignition type internal combustion engine, for example, a mixture of fuel (gasoline) and intake air (premixed gas) is pre-ignited by compression in the combustion chamber 26 (premixed compression self-ignition, Homogeneous Charge Compression). Ignition) Combustible HCCI combustion is possible.

  DESCRIPTION OF SYMBOLS 12 ... Main motor generator, 14 ... Battery, 16 ... Auxiliary motor generator, 18 ... Engine, 32 ... Intake passage, 44 ... Exhaust passage, 46 ... Catalyst, 48 ... Heat recovery device, 60 ... Navigation device, 62 ... ECU ( An embodiment of an electric vehicle control apparatus).

Claims (11)

A battery having only a main machine rotating machine as an in-vehicle main machine and serving as a power supply source for the main machine rotating machine, an auxiliary machine rotating machine for charging the battery, and an engine serving as a power supply source for the auxiliary machine rotating machine, Applied to an electric vehicle including an exhaust purification catalyst provided on an exhaust passage of the engine;
Request for execution of power generation mode processing for driving the engine and generating electric power in the auxiliary rotating machine based on at least one of the temperature of the catalyst and the information about the destination set by the instruction means operated by the user The engine output shaft rotation energy transmitted to the accessory rotating machine is made smaller than that during execution of the power generation mode process before the predicted execution request is generated. An electric vehicle control device comprising: control means for executing a catalyst warm-up mode process for warming up the catalyst by driving. The control means performs the power generation mode process when it is determined that the stored amount of the battery is less than a first specified amount,
In the catalyst warm-up mode process, it is determined that the storage amount of the battery is equal to or more than the first specified amount and less than a second specified amount that is higher than the first specified amount, and 2. The control device for an electric vehicle according to claim 1, wherein the control is performed to drive the engine when it is determined that the temperature of the catalyst is lower than a specified temperature.   The control apparatus for an electric vehicle according to claim 2, wherein the specified temperature is a warm-up preparation temperature equal to or higher than an activation temperature of the catalyst. The specified temperature is a warm-up preparation temperature equal to or higher than the activation temperature of the catalyst,
4. The control apparatus for an electric vehicle according to claim 2, wherein the second specified amount is set higher as the temperature of the catalyst is lower. The engine is a spark ignition type equipped with a spark plug that generates a discharge spark in a combustion chamber of the engine,
5. The control of an electric vehicle according to claim 1, wherein the catalyst warm-up mode process delays an ignition timing by the spark plug from a time when the power generation mode process is executed. 6. apparatus. The control means executes the power generation mode process when it is determined that the stored amount of the battery is less than a first specified amount,
In the catalyst warm-up mode process, it is determined that the storage amount of the battery is equal to or more than the first specified amount and less than a second specified amount that is higher than the first specified amount, and When the temperature of the catalyst is determined to be lower than the warm-up preparation temperature equal to or higher than the activation temperature of the catalyst, a process of driving the engine,
The control means continues the execution of the catalyst warm-up mode process until the temperature of the catalyst reaches a warm-up determination temperature higher than the warm-up preparation temperature, and then shifts to the power generation mode process. The control device for an electric vehicle according to any one of claims 2 to 5.   The control means executes the power generation mode process when it is determined that the charged amount of the battery is less than a first specified amount, and the destination is set to the destination set via the instruction means. The process for prohibiting the execution of the power generation mode process is executed when a storage amount of the battery assumed when the vehicle arrives is equal to or greater than a predetermined threshold value less than the first specified amount. Item 7. The control device for an electric vehicle according to any one of Items 1 to 6. A required power amount calculating means for calculating an amount of power required for the vehicle to reach the set destination based on information on the destination set via the instruction means;
Based on the amount of power calculated by the required power amount calculation means and the amount of power stored in the battery, it is determined whether the vehicle can reach the set destination without executing the power generation mode process. And a judging means for
8. The control apparatus for an electric vehicle according to claim 7, wherein the prohibiting process is a process of prohibiting the execution of the power generation mode process when it is determined that the determination unit is reachable. The instructing means is an in-vehicle navigation device having a function of grasping a current position of the vehicle and a function of setting a destination of the vehicle by a user,
The said request | requirement electric energy calculation means calculates the electric energy which the said vehicle requires based on the driving | running route from the present position grasped | ascertained by the said navigation apparatus to the said set destination. Control device for electric vehicle. The navigation device stores information about the battery charging location,
Based on the information on the stored charging location, when it is determined that the charging destination does not exist at the set destination, or it is determined whether the charging location is present at the set destination. The control device for an electric vehicle according to claim 9, further comprising release means for canceling prohibition of execution of the power generation mode process. The vehicle is provided with a recovery means for recovering exhaust heat exhausted from the engine,
The heating apparatus according to any one of claims 1 to 10, further comprising heating means for driving the engine and heating the exhaust air collected by the collecting means when it is determined that there is a request for heating the passenger compartment. The control device for an electric vehicle according to claim 1.

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