JP2009262771A - Hybrid vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress emission at the time of starting an internal combustion engine while suppressing reduction of excessive electricity consumption and accumulated electricity amount in a hybrid vehicle. <P>SOLUTION: In a hybrid vehicle 10, an ECU 100 starts charging a battery 600 by energizing the battery 600 when electricity supply from an external power source 20 via a charging plug 700 exists. In this case, a target accumulated electricity amount SOCtag of the battery 600 is set to a controlled maximum value SOCmax in an area where a catalyst temperature Tc is not less than a determination reference value Tcth. In contrast, when the catalyst temperature Tc is lowered to less than the determination reference value Tcth, the controlled maximum value SOCmax is increased and corrected according to a catalyst temperature deviation ΔTc between a target catalyst temperature Tctag and a catalyst temperature Tc. At the time of starting the hybrid vehicle 10, the accumulated electricity raised according to increased correction amount of the target accumulated electricity amount is used for energizing an EHC 400. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a control device for a hybrid vehicle including an electric motor and an internal combustion engine as a power source.

  As a hybrid vehicle, a vehicle having an EHC (Electric Heating Catalyst) in an exhaust path of an internal combustion engine has been proposed (see, for example, Patent Document 1). According to the exhaust gas reduction device for a hybrid vehicle disclosed in Patent Document 1 (hereinafter referred to as “first prior art”), the catalyst is heated in advance while the motor is started and the engine is stopped. It is said that the exhaust gas generated at the start-up can be efficiently purified by allowing the engine to be driven after determining that the catalyst has reached a sufficient activation temperature.

  On the other hand, a vehicle that can be charged from an external power supply (hereinafter referred to as “second prior art”) has also been proposed (see, for example, Patent Document 2).

JP-A-8-338235 JP 2007-245999 A

  The hybrid vehicle can perform so-called EV (Electric Vehicle) traveling only by the power of the electric motor when starting, starting, or traveling at a low speed and a light load. Therefore, as in the first prior art, it is possible to heat the catalyst before starting the internal combustion engine, but since the electric power to be used for heating the catalyst is brought out from the power storage means such as a battery, If the catalyst warm-up is promoted while the internal combustion engine is stopped as in the first prior art, the electric power to be used for EV traveling is reduced by that amount, which may hinder the traveling performance of the hybrid vehicle.

  On the other hand, according to the second prior art, charging can be performed with electric power supplied from the outside in the soak state, so that, for example, power is supplied to the EHC at the time of charging, while suppressing a decrease in the amount of power stored in the battery. It is theoretically possible to complete the catalyst warm-up when the internal combustion engine is started. However, when the EHC is energized during charging as described above, it is unclear when the hybrid vehicle will leave the soak state, resulting in an increase in wasted energization to the EHC and excessive power consumption. This can lead to consumption.

  In other words, the combination of these conventional technologies, apart from whether they are easy to combine, suppresses emissions at the start of the internal combustion engine while suppressing both excessive power consumption and a decrease in the amount of stored electricity. However, at least the technical problem that it is extremely difficult to practice remains unsolved.

  The present invention has been made in view of such problems, and is a hybrid vehicle control device capable of suppressing emissions at the time of starting an internal combustion engine while suppressing both excessive power consumption and a decrease in the amount of stored electricity. It is an issue to provide.

  In order to solve the above-described problems, a control apparatus for a hybrid vehicle according to the present invention includes an internal combustion engine, at least one electric motor that functions as a power source together with the internal combustion engine, functions as a power source for the electric motor, and is supplied from an external power source. By means of energization using the stored electricity that can be charged by external power, a catalyst that is installed in the exhaust path of the internal combustion engine and that can purify the exhaust of the internal combustion engine, and the stored electricity that is stored in the electricity storage means A control apparatus for a hybrid vehicle, comprising: heating means capable of heating a catalyst; and energization means for performing charging and energization, the identifying means for identifying a catalyst temperature as the temperature of the catalyst, and the identification Setting means for setting a target value of the amount of electricity stored in the electricity storage means based on the catalyst temperature that has been set, and the amount of electricity stored during the supply period of the external power Characterized by comprising a control means for controlling said energizing means so as to Shirubechi.

  The “internal combustion engine” in the present invention has, for example, a plurality of cylinders, and at least the power of explosive power generated when various fuels such as gasoline, light oil or alcohol burn in the combustion chambers of the plurality of cylinders. This is a concept that includes a part of an engine that can be output to an axle of a hybrid vehicle via an output shaft such as a crankshaft via a mechanical transmission path such as a piston and a connecting rod. Cycle reciprocating engine.

  Further, the hybrid vehicle according to the present invention includes an electric motor that can take the form of, for example, a motor or a motor generator as a power source different from the internal combustion engine. For example, an inverter, various PCUs (Power Control Units), and the like are provided. Through the various power controls such as current control, voltage control, and power control, power corresponding to the discharge power from the battery or the like can be output to the axle. In this internal combustion engine, for example, a generator that can take the form of a generator or a motor generator, for example, directly or indirectly is connected to an engine output shaft such as a crankshaft. It may be configured to be possible.

  The hybrid vehicle according to the present invention includes power storage means such as a hybrid battery configured to function as a power source for the electric motor. This power storage means is suitably used as a suitable form, for example, when the electric motor according to the present invention functions as power regeneration means, etc., or when the hybrid vehicle includes a generator, for example, depending on the generated power. In particular, the present invention has a configuration in which charging is appropriately performed by energization using external power supplied from an external power source (that is, different from power generated inside the hybrid vehicle).

  Here, the “external power source” refers to, for example, various types of power sources that are installed at home or have portability (suitable forms include, for example, a household outlet and a dedicated or general-purpose charging plug as appropriate), Alternatively, it refers to various power sources or the like installed as dedicated or general-purpose infrastructure facilities or the like in urban areas or suburban areas (which may be attached to, for example, a gas station or a similar infrastructure facility). That is, the hybrid vehicle according to the present invention is a so-called plug-in hybrid vehicle configured to be able to control the charging state of the power storage means relatively freely based on the driver's intention and the like.

  On the other hand, the exhaust path of the internal combustion engine according to the present invention may take various forms of, for example, a three-way catalyst, an NSR catalyst (NOx storage reduction catalyst) or an oxidation catalyst, or S / C (Start Converter) depending on the installation location. Various catalysts that can take a form such as a catalyst or an underfloor catalyst are provided as at least a part of the exhaust purification means that can take various forms. This catalyst is directly or indirectly generated by heat applied from the heating means when energized using stored power to a heating means that can take the form of, for example, a hot wire, a heater coil, or a ceramic heater. It is the structure heated automatically.

  The structure of the heating means (especially the physical, mechanical, and electrical structure) allows the heating means to heat the catalyst by supplying heat to the catalyst when energized (in other words, it can be warmed up). As long as the catalyst is partly or entirely surrounded by a heat ray or similar means, the catalyst may be warmed up by direct heat transfer, for example, the exhaust upstream side of the catalyst. For example, the catalyst may be indirectly warmed up by radiant heat. Further, the heating means may be configured integrally with the catalyst, or may be disposed close to the upstream side thereof and may be configured as a part of so-called EHC.

  The hybrid vehicle according to the present invention has, for example, a current control circuit, a voltage control circuit, and power control for performing the above-described charging (strictly energizing for charging) and energizing (strictly energizing for heating). There are provided energization means appropriately including various electric circuits such as circuits, switching circuits or rectifier circuits and various elements such as various electric wirings. The configuration of the energization means adopts various modes depending on the physical, mechanical, or electrical connection mode among the external power source, the power storage means, and the heating means. For example, the supply path of the external power is the power storage means side and the heating means. In the case where there are at least two systems with the side, as a preferred embodiment, there may be provided switching means or the like capable of at least substantially selectively switching these. For example, external power is directly supplied to the heating means. When not connected, it may be divided into an electric system that guides external power to the power storage means and an electric system that supplies power from the power storage means to the heating means. Whatever form is adopted, the “energization means” according to the present invention is configured to vary the execution state of charging and energization in a binary, stepwise or continuously manner.

  According to the control apparatus for a hybrid vehicle of the present invention, during its operation, the control can take the form of various processing units such as an ECU (Electronic Control Unit), various controllers or various computer systems such as a microcomputer device. The means controls the energization means so that the storage amount becomes a target value during the external power supply period.

  Here, in view of the situation on the power storage means side, the target power storage amount at the time of charging may be, for example, the maximum power storage amount on the control set as a fixed value in advance, and does not necessarily need to be a variable value.

  On the other hand, from the viewpoint of suppressing excessive consumption of external power, the power stored in the power storage means is used in a period excluding this type of supply period (in short, a period after the start of the hybrid vehicle). When energization is performed, a decrease in the amount of electricity stored in the electricity storage means becomes an unavoidable problem, and even if the amount of electricity stored at the time of completion of charging is constant (that is, the target value is a fixed value) There is a high possibility that the amount of electricity stored in the electricity storage means afterwards will be indefinite.

  Therefore, according to the control apparatus for a hybrid vehicle according to the present invention, during operation, the catalyst temperature is specified by specifying means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. Is done.

  Here, “specific” according to the present invention means that a specific target or a physical quantity correlated with the specific target is detected directly or indirectly through a predetermined detection means, or directly through the detection means. Or selecting a corresponding value from a map or the like stored in advance in a suitable storage means based on a physical quantity correlated with a specific target detected indirectly, or a physical quantity or selected value correlated with this type of specific target It is a broad concept that includes deriving according to a preset algorithm or calculation formula from the above, or simply obtaining the value detected, selected or derived in this way, for example, in the form of an electrical signal, etc. .

  In the scope of such a concept, the specifying means may specify the catalyst temperature in any way, for example, from a detecting means such as a temperature sensor, which is directly installed on the catalyst or is installed on the catalyst. This type of identification may be performed by acquiring the temperature of the corresponding part, and various index values (for example, cooling water temperature, etc.) that can alternatively represent the catalyst temperature with an accuracy that is not practically insufficient are acquired. Thus, this type of identification may be made without detection of the actual catalyst temperature.

  On the other hand, after the specification of the catalyst temperature, for example, by the setting means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, the above-described stored amount of electricity based on the specified catalyst temperature The target value is set.

  The catalyst temperature correlates with the energization amount required when energization of the heating means is performed after the hybrid vehicle is started, for example. In other words, even if the actual energization amount is unknown unless the energization is actually performed, it is clear that, as a qualitative tendency, the level of the catalyst temperature corresponds to the magnitude of the energization amount.

  Therefore, by setting the target value for the amount of electricity stored based on the catalyst temperature, the decrease in the amount of electricity stored in the electricity storage means upon energization of the heating means is somewhat suppressed. That is, according to the hybrid vehicle control apparatus of the present invention, it is possible to suppress emissions at the time of starting the internal combustion engine while suppressing both excessive power consumption and a decrease in the amount of stored electricity.

  Note that the present invention has been made paying attention to the fact that the electric power brought out from the power storage means to be supplied to the heating means changes according to the catalyst temperature, and the amount of power stored when the power storage means is charged. This has a remarkable and high effect in considering the catalyst temperature when setting the target value. Therefore, as the setting mode of the target value based on the catalyst temperature, various modes that are not uniquely defined can be adopted. For example, as an extreme example, the target value is binary according to the level of the catalyst temperature. It may be switched to. In this case as well, it is obvious that the target value is clearly advantageous as a fixed value.

  In one aspect of the control apparatus for a hybrid vehicle according to the present invention, the setting means responds to the deviation so that the magnitude of the deviation between the target value of the catalyst temperature and the specified catalyst temperature corresponds to increase or decrease, respectively. To set a target value of the charged amount.

  According to this aspect, the target value of the charged amount (hereinafter, referred to as “target catalyst temperature” as appropriate to distinguish from the target value of the charged amount) and the target value of the charged amount ( Hereinafter, in order to distinguish from the target value of the catalyst temperature, it is appropriately set as “target power storage amount”). Since this deviation has a unique relationship with the electric power taken out from the power storage means when the heating means is energized, the target power storage amount is set according to the deviation, so that excessive consumption of external power is reduced. It is possible to suppress as much as possible and suppress the decrease in the amount of electricity stored in the electricity storage means as much as possible, which is beneficial in practice.

  Note that “according to the deviation” described here does not only indicate that the deviation and the target power storage amount change one-on-one, but the deviation and the target power storage amount are one-to-one, one-to-many, many pairs. It is a concept that encompasses one-to-many and many-to-many correspondence. For example, even if the deviation occurs, if the catalyst temperature is equal to or higher than a preset lower limit value (for example, the catalyst activation temperature or a value in the vicinity thereof), the catalyst temperature is raised to the target catalyst temperature. In view of the fact that the energization amount required to squeeze may be relatively small, the target power storage amount is set to a preset fixed value or the like without setting the target power storage amount according to this type of deviation. Is also a good idea.

  In this aspect, the setting means may set the target value for the charged amount by correcting a preset reference value for the target value for the charged amount in accordance with the deviation.

  Here, the reference value of the target power storage amount may basically be any value, but in view of the characteristics of the hybrid vehicle that is repeatedly charged and discharged appropriately during traveling, at least physical or electrical A value that is less than the theoretical maximum amount of electricity that can be determined (the amount of electricity that is theoretically impossible to store more than that theoretically or due to some restriction (for example, causing failure or malfunction)) It is. The reference value of the target power storage amount is, as a preferred form, at least some practical problem with respect to charge / discharge that can be assumed for a hybrid vehicle experimentally, empirically, theoretically or based on simulations in advance. It may be the maximum amount of electricity stored in the control that is defined in a range that does not cause it to occur. In this case, ideally, after the energization to the heating means is completed, the charged amount returns to the maximum charged amount in the control.

  According to this aspect, the reference value is corrected to increase or decrease in accordance with the magnitude of the deviation, so that after the energization to the heating means is finished (that is, ideally, when the catalyst temperature reaches the target catalyst temperature). It is possible to maintain the amount of electricity stored in the electricity storage means at least approximately constant regardless of the deviation. That is, in simple terms, the charged amount is raised from the reference value in accordance with the deviation, and electric power corresponding to the raised amount is used when the heating means is energized. For this reason, according to this aspect, it is possible to suitably suppress excessive consumption of electric power and a decrease in the amount of electric power stored in the electric storage means.

  In addition, when the reference value is set to the maximum storage amount for control in this way, the target storage amount is restricted to the theoretical maximum value described above by performing correction according to the deviation of the catalyst temperature. There is a possibility. In such a case, of course, the target storage amount may be set with the theoretical maximum value as an upper limit. For example, if it is temporary, the storage amount exceeds this type of theoretical maximum value. If this is feasible, the theoretical maximum value of this kind is exceeded only if, for example, it is clear that the energization of the heating means will be started in the near future, or that can be estimated. It may be set in another area. Thus, with some discipline on the upper limit side, the practical benefits obtained by this aspect are clearly significant.

  In another aspect of the hybrid vehicle control device according to the present invention, the control means controls the energization means so that the energization is performed when a start input for starting the hybrid vehicle is made. .

  According to this aspect, when a start input such as an ignition operation (for example, an appropriate operation to be performed on various operation means such as an ignition key or a push-type start button) is given to start the hybrid vehicle, the heating means Is energized. The start timing of the hybrid vehicle does not necessarily coincide with the start timing of the internal combustion engine. When the heating means is energized in response to this type of start input, the catalyst warm-up is performed at the start timing of the internal combustion engine. Is ideally effective in suppressing emissions at the time of starting the internal combustion engine, since at least some catalyst warm-up can be promoted.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

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

<Configuration of Embodiment>
First, with reference to FIG. 1, the structure of the hybrid vehicle 10 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic block diagram conceptually showing the configuration of the hybrid vehicle 10.

  In FIG. 1, the hybrid vehicle 10 includes a speed reduction mechanism 11 and wheels 12, an ECU 100, an engine 200, a motor generator MG <b> 1 (hereinafter abbreviated as “MG1” as appropriate), and a motor generator MG2 (hereinafter abbreviated as “MG2” as appropriate). ), A power split mechanism 300, an EHC 400, a PCU 500, a battery 600, a charging plug 700, and a relay circuit 800, which is an example of a “hybrid vehicle” according to the present invention.

  The speed reduction mechanism 11 is a gear mechanism that includes a differential gear (not shown) that is configured to rotate according to the power output from the engine 200 and the motor generator MG2, and the rotational speed of these power sources is set to a predetermined value. It can be decelerated according to the reduction ratio. The output shaft of the speed reduction mechanism 11 is connected to the axle (not shown) of the hybrid vehicle 10, and the power of these power sources is the driving wheel connected to the axle and the axle with the rotational speed reduced. It is comprised so that it may be transmitted to the wheel 12 as.

  The configuration of the speed reduction mechanism 11 is not limited in any way as long as the power supplied from the engine 200 and the motor generator MG2 can be transmitted to the axle while reducing the rotational speed of the shaft body based on the power. It may have a configuration including a differential gear or the like, or may be configured to be able to obtain a plurality of gear ratios as a so-called reduction mechanism including a plurality of clutches and brakes and a planetary gear mechanism. .

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like and is configured to be able to control the entire operation of the hybrid vehicle 10. 1 is an example of a “hybrid vehicle control device” according to the invention; The ECU 100 is configured to be able to execute battery charging control described later in accordance with a control program stored in the ROM.

  The ECU 100 is an integrated electronic control unit configured to function as an example of each of the “specifying unit”, “setting unit”, and “control unit” according to the present invention. All are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of each of the units according to the present invention are not limited to this. For example, each of these units includes a plurality of ECUs, various processing units, various controllers, a microcomputer device, and the like. It may be configured as various computer systems.

  The engine 200 is a gasoline engine that is an example of an “internal combustion engine” according to the present invention that is configured to function as a main power source of the hybrid vehicle 10. Here, a detailed configuration of the engine 200 will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view conceptually and schematically illustrating a cross-sectional configuration of the engine 200. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, an engine 200 burns an air-fuel mixture through an ignition operation by an ignition device 202 in which a part of a spark plug (not shown) is exposed in a combustion chamber in a cylinder 201, and an explosive force due to such combustion. The reciprocating motion of the piston 203 that occurs in response to the above is converted into the rotational motion of the crankshaft 205 via the connecting rod 204. Further, a crank position sensor 206 that detects a rotational position (that is, a crank angle) of the crankshaft 205 is installed in the vicinity of the crankshaft 205. The engine 200 is an in-line four-cylinder engine in which four cylinders 201 are arranged in series in a direction perpendicular to the paper surface. However, since the configurations of the individual cylinders 201 are equal to each other, in FIG. Only the cylinder 201 will be described.

  The “internal combustion engine” according to the present invention is not limited to a gasoline engine, and may have a form such as a diesel engine using light oil as a fuel or a bi-fuel engine capable of using a mixed fuel of alcohol and gasoline. . Moreover, even if it is a gasoline engine, the cylinder arrangement | sequence is not limited in series.

  In the engine 200, the air sucked from the outside passes through the intake pipe 207 and is mixed with the fuel injected from the injector 212 in the intake port 210 to become the above-mentioned air-fuel mixture. The fuel is stored in a fuel tank (not shown), and is pumped and supplied to the injector 212 via a delivery pipe (not shown) by the action of a feed pump (not shown). The form of the injection means for injecting the fuel does not have to adopt a so-called intake port injection type injector as shown in the figure. For example, the pressure of the fuel pumped by a feed pump or other low-pressure pump is further increased to a high-pressure pump. It may have a form such as a so-called direct injection injector that is configured to be capable of boosting pressure and directly injecting fuel into the high-temperature and high-pressure cylinder 201.

  The communication state between the inside of the cylinder 201 and the intake pipe 207 is controlled by opening and closing the intake valve 211. The air-fuel mixture combusted inside the cylinder 201 becomes exhaust and is led to the exhaust pipe 215 via the exhaust port 214 when the exhaust valve 213 that opens and closes in conjunction with opening and closing of the intake valve 211 is opened. The exhaust pipe 215 is an example of the “exhaust path” according to the present invention.

  On the other hand, on the upstream side of the intake port 210 in the intake pipe 207, a throttle valve 208 for adjusting the intake air amount related to the intake air guided through a cleaner (not shown) is disposed. The throttle valve 208 is configured such that its drive state is controlled by a throttle valve motor 209 electrically connected to the ECU 100. The throttle valve motor 209 is basically driven and controlled by the ECU 100 so that a throttle opening corresponding to an accelerator opening detected by an accelerator position sensor (not shown) is obtained. It is not necessary to intervene (in a range that does not contradict the driver's intention), and it is also possible to automatically adjust the throttle opening. That is, the throttle valve 209 is configured as a kind of electronically controlled throttle valve.

  An EHC 400 is installed in the exhaust pipe 215. Here, the EHC 400 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view conceptually showing a cross-sectional configuration of the EHC 400 along the extending direction of the exhaust pipe 215. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 3, the EHC 400 includes a case 410, a three-way catalyst 420, and a heater 430.

  The case 410 is a housing of the EHC 400 that houses the three-way catalyst 420 and the heater 430 therein. The case 410 is a metallic cylindrical member in which a cross section in a direction orthogonal to the flow of exhaust (that is, a direction perpendicular to the paper surface) forms an annular shape, and is electrically grounded.

  The three-way catalyst 420 is configured to be capable of purifying CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively. Is a catalytic converter as an example.

  The heater 430 is a resistor whose cross section in a direction orthogonal to the flow of exhaust gas described above forms a spiral, and is an example of the “heating means” according to the present invention. The heater 430 does not have at least electrical insulation characteristics, and is preferably made of a metallic material that can flow a current corresponding to an applied voltage when energized as described later. One end of the heater 430 is connected to the case 410 and is grounded in terms of potential. On the other hand, the other end (not shown) of the heater 430 is electrically connected to a PCU 500 described later, and is configured to be energized as described above. At this time, the material constituting the heater 430 is not limited by the physical property value defining the conductivity such as the electrical resistance value or the conductivity, for example, as long as the material can generate heat by energization. For example, a metal material having (that is, a conductive characteristic defined by a relatively low electric resistance value) or a relatively low conductive characteristic (that is, a conductive characteristic defined by a relatively high electric resistance value), A material generally called a resistor may be used.

  Returning to FIG. 2, the EHC 400 is provided with a temperature sensor 216 configured to be able to detect the catalyst bed temperature Tc as the temperature of the three-way catalyst 420. The temperature sensor 216 is electrically connected to the ECU 100, and the detected catalyst bed temperature Tc is referred to by the ECU 100 at a constant or indefinite period.

  The exhaust pipe 215 is provided with an air-fuel ratio sensor 217 configured to be able to detect the exhaust air-fuel ratio of the engine 200. Further, a water temperature sensor 218 for detecting a cooling water temperature related to cooling water (LLC) circulated and supplied to cool the engine 200 is disposed in a water jacket installed in a cylinder block that accommodates the cylinder 201. ing. The catalyst bed temperature Tc described above may alternatively be detected by the cooling water temperature detected by the water temperature sensor 218. In this case, a map or the like that defines the correlation between the coolant temperature and the catalyst bed temperature Tc may be stored in the ROM of the ECU 100.

  Returning to FIG. 1, the motor generator MG1 is configured to function as a generator for charging the battery 600 or supplying power to the motor generator MG2, and further as an electric motor for assisting the power of the engine 200. Yes.

  The motor generator MG2 is a motor generator that is an example of the “motor” according to the present invention, and is configured to function as a motor that assists the power of the engine 200 or as a generator that charges the battery 500. .

  The motor generator MG1 and the motor generator MG2 are configured as, for example, a synchronous motor generator, and include a rotor having a plurality of permanent magnets on the outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. Prepare. However, other types of motor generators may be used.

  The power split mechanism 300 is a planetary gear mechanism configured to be able to distribute the power of the engine 200 to the MG 1 and the axle. In addition, since the structure of the power split mechanism 300 can take various well-known aspects, a detailed description thereof is omitted here, but in brief, the power split mechanism 300 includes a sun gear provided at the center, A ring gear concentrically provided on the outer periphery of the sun gear, a plurality of pinion gears disposed between the sun gear and the ring gear and revolving while rotating on the outer periphery of the sun gear, and coupled to an end of the crankshaft 205, And a planetary carrier that supports the rotation shaft of each pinion gear.

  This sun gear is coupled to a rotor (not shown) of MG1 via a sun gear shaft, and the ring gear is coupled to a rotor (not shown) of MG2 via a ring gear shaft. The ring gear shaft is connected to the axle, and the power generated by the MG 2 is transmitted to the axle via the ring gear shaft, and the driving force from the wheel 12 similarly transmitted via the axle is the ring gear shaft. Is input to MG2. Under such a configuration, the power generated by the engine 200 is transmitted to the sun gear and the ring gear by the planetary carrier and the pinion gear, and the power of the engine 200 is divided into two systems.

  PCU 500 converts DC power extracted from battery 600 into AC power and supplies it to motor generator MG1 and motor generator MG2, and also converts AC power generated by motor generator MG1 and motor generator MG2 into DC power. It includes an inverter (not shown) configured to be able to supply to the battery 600, input / output of power between the battery 600 and each motor generator, or input / output of power between the motor generators (ie, In this case, the power control unit is configured to be able to control the power transmission / reception between the motor generators without using the battery 600. The PCU 500 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  On the other hand, the PCU 500 is also electrically connected to the EHC 400, and is configured to be able to supply the DC drive voltage Vd to the EHC 400. The heater 430 of the EHC 400 generates a drive current Id corresponding to the DC drive voltage Vd, and the heater 430 generates heat by the drive current Id. That is, the PCU 500 is an example of the “energizing unit” according to the present invention. Supplementally, the PCU 500 includes a booster circuit such as a DC-DC converter, and the drive voltage Vd supplied to the heater 430 can be variably controlled at least in binary.

  In the present embodiment, the PCU 500 is an example of the “energizing unit” in the present invention, but the mode of the energizing unit is as long as energization to the EHC 400 (in this embodiment, energization to the heater 430) is possible. This is not intended to be limited in any way. For example, in the hybrid vehicle 10, as an example of the “energization unit” according to the present invention, the primary voltage supplied from the battery 600 or other power storage unit or the like can be boosted to a high voltage of, for example, several hundred volts. A secondary voltage supply device may be provided. Alternatively, the EHC 400 may be directly connected to the battery 600 without using the PCU 500 or indirectly through a switching circuit, a relay circuit, or the like.

  The battery 600 is a rechargeable storage battery configured to be able to function as a power supply source related to the power for powering the motor generator MG1 and the motor generator MG2, and is an example of the “storage means” according to the present invention. is there. Here, the battery 600 is configured to be appropriately chargeable by an external power source 20 installed outside the hybrid vehicle 10 (that is, an example of the “external power source” according to the present invention). That is, the battery 600 is configured to be charged not only by the electric power generated by the power generation action of each motor generator but also by the power supply from the external power source 20.

  An SOC sensor 610 is attached to the battery 600. The SOC sensor 610 is a storage amount SOC of the battery 600 (an index value that defines the storage state of the battery. Here, the value corresponding to the fully discharged state is 0 (%), and the value corresponding to the fully charged state is 100 ( %) Is a sensor that can detect a standardized value. The SOC sensor 610 is electrically connected to the ECU 100, and the detected SOC is referred to by the ECU 100 at a constant or indefinite period as an example of the “amount of stored electricity” according to the present invention. .

  The charging plug 700 is a metal plug that is electrically connected to the input terminal of the relay circuit 800 and that can be electrically connected to the external power supply 20. The external power source 20 may be a household 100 V power source, for example, or may be installed as an infrastructure facility in an appropriate infrastructure facility (for example, a gas station or a service station) in an urban area or a suburb. The physical, mechanical, mechanical, electrical or chemical aspects are not limited in any way.

  The relay circuit 800 is a switching circuit that can selectively and selectively switch an electrical connection state between an input terminal on the charging plug 700 side and an output terminal on the battery 600 side (in FIG. 1, connection). Not shown). The relay circuit 800 is electrically connected to the ECU 100, and the connection state is controlled by the ECU 100. In the state where the input terminal and the output terminal are electrically connected (hereinafter referred to as “ON state” as appropriate), the battery 600 is electrically connected to the charging plug 700, and the charging plug 700 is externally connected. When the power supply 20 is connected, the battery 600 is automatically energized halfway and charging is started, and the input terminal and the output terminal are not connected (hereinafter referred to as appropriate). In the “off state”), the battery 600 is released from the charging plug 700, and the power supply to the battery 600 is stopped regardless of whether the charging plug 700 is connected to the external power source 20 or not. Yes.

<Operation of Embodiment>
Next, with reference to FIG. 4, the details of the battery charging control executed by the ECU 100 will be described as the operation of the present embodiment. FIG. 4 is a flowchart of battery charging control.

  In FIG. 4, the ECU 100 determines whether or not the hybrid vehicle 10 is in the soak state (step S101). Here, the “soak state” according to the present embodiment refers to a state in which all of the motor generator MG2, the motor generator MG1, and the engine 200 are stopped. The ECU 100 is a control unit that controls the operation of the engine 200 and each motor generator. The ECU 100 can easily determine whether or not the hybrid vehicle 10 is in the soak state. For example, the ECU 100 performs the determination based on whether or not the rotational speeds of the engine 200 and each motor generator are zero. Alternatively, the determination may be performed based on the operating state of the ignition switch that prompts the engine 200 to start and the power supply state of the PCU 500.

  When the hybrid vehicle 10 is not in the soak state (step S101: NO), the ECU 100 ends the battery charging control. On the other hand, when it is determined that the hybrid vehicle 10 is in the soak state (step S101: YES), the ECU 100 determines whether the charging plug 700 is connected to the external power source 20 (step S102). Whether or not the charging plug 700 is connected to the external power source 20 can be determined based on the terminal voltage of the charging plug 700. For example, if the external power supply 20 is a household 100V power supply, the terminal voltage is 100V. If a general expression that does not depend on the type of the external power supply 20 is used, the terminal voltage of the input terminal is approximately 0 V when the charging plug 700 is not connected to the external power supply 20. If it is equal to or greater than the set threshold value, it may be determined that the charging plug 700 is connected to the external power source 20. If charging plug 700 is not connected to external power supply 20 (step S102: NO), the process returns to step S101, and the process is controlled to be substantially in a standby state.

  On the other hand, when charging plug 700 is connected to external power supply 20 (step S102: YES), ECU 100 determines whether catalyst temperature Tc is equal to or higher than determination reference value Tcth (step S103). Here, the judgment reference value Tcth is set to a temperature near the catalyst activation temperature of the three-way catalyst 420, and is set to 400 ° C. in the present embodiment.

  When catalyst temperature Tc is equal to or higher than determination reference value Tcth (step S103: YES), ECU 100 sets target storage amount SOCtag, which is a target value of storage amount SOC of battery 600, to a preset maximum value SOCmax on control. (Step S104). Here, the maximum value SOCmax in control is a value less than the physical upper limit value of the charged amount of the battery 600 (that is, the charged limit, and here, the SOC is assumed to be 100 (%)). In addition, in the course of charging / discharging, which is repeated as appropriate during the traveling period of the hybrid vehicle 10, based on experimental, empirical, theoretical or simulation in advance, both the SOCs of electric storage exceed the physical upper limit value. However, it does not decrease to the lower limit value of the charged amount (for example, SOC = 0 (%), that is, a value corresponding to a complete discharge state, or a value at which the auxiliary machinery can be driven at a minimum). Is set as high as possible. The SOCmax is a value of about 70 (%) to 90 (%), for example. When the target charged amount SOCtag is set to the control maximum value SOCmax, the process proceeds to step S107.

  When the catalyst temperature Tc is less than the determination reference value Tcth in the determination process according to step S103 (step 103S: NO), the ECU 100 calculates the catalyst temperature deviation ΔTc according to the following equation (1) (step S105).

ΔTc = Tcttag−Tc (1)
Here, Tcttag is a target catalyst temperature that is a target value of the catalyst temperature Tc when the EHC 400 is energized, and is set to a value in the vicinity of 600 ° C. in this embodiment. When catalyst temperature deviation ΔTc is calculated, ECU 100 calculates target charged amount SOCtag in accordance with the following equation (2) (step S106).

SOCtag = SOCmax + f (ΔTc) (2)
Here, f (ΔTc) is a storage amount correction value and is a function of the catalyst temperature deviation ΔTc. The charged amount correction value f is a value in which the magnitude of the catalyst temperature deviation ΔTc corresponds linearly to the magnitude. More specifically, the charged amount correction value f is previously set experimentally, empirically, theoretically, or based on simulation, and the catalyst temperature deviation ΔTc and the deviation is zero (that is, the catalyst is corrected). The relationship between the energization amount to the EHC 400 required to raise the temperature Tc to the target catalyst temperature Tctag) is defined by quantification, and if the catalyst temperature deviation ΔTc is determined, it is uniquely corrected by one storage amount. The value f is derived. It should be noted that the manner of setting the storage amount correction amount f shown here is merely an example, and the above-described relationship does not necessarily have to be linear.

  In addition, supplementally, the target storage amount SOCtag calculated according to the following equation (2) is bound to the theoretical maximum value described above. That is, as a result of the numerical calculation based on the above equation (2), the calculated target charged amount SOCtag is set with the theoretical maximum value as the maximum value. If it is allowed to exceed this type of rated value temporarily, the target storage amount SOCtag may be set in a region that is limited to the theoretical maximum value or more. When step S106 ends, the process proceeds to step S107.

  In the above equation (2), the maximum control value SOCmax is corrected in accordance with the catalyst temperature deviation ΔTc. That is, the control maximum value SOCmax is an example of the “reference value of the target amount of power storage” according to the present invention.

  In step S107, the relay circuit 800 is controlled to be on by the control of the ECU 100 (step S107). When relay circuit 800 is controlled to be in an ON state, energization to battery 600 using external power supplied from external power supply 20 is started, and charging of battery 600 is started.

  When charging of battery 600 is started, ECU 100 determines whether or not storage amount SOC is equal to or greater than target storage amount SOCtag (step S108). When the stored electricity amount SOC is less than the target stored electricity amount SOCtag (step S108: NO), the process returns to step S101, and a series of processes is repeated. On the other hand, when the storage amount SOC is equal to or greater than the target storage amount SOCtag (step S108: YES), the ECU 100 assumes that the charging of the battery 600 has been completed, and controls the relay circuit 800 to be in an off state (step S109). Returning to step S101, a series of processing is repeated. That is, in the battery charging control, basically, as long as the hybrid vehicle 10 is in the soak state and the charging plug 700 is connected to the external power source 20, the battery 600 is maintained until the charged amount SOC reaches the target charged amount SOCtag. The energization of is continued.

  Here, when the hybrid vehicle 10 has escaped from the soak state (that is, the start is requested by an ignition operation or the like), the battery charging control is terminated as described above, while the ECU 100 detects the catalyst temperature Tc. In response to this, energization to the EHC 400 is started as appropriate.

  More specifically, ECU 100 controls PCU 500 to supply DC drive voltage Vd described above to heater 430. As a result, a driving current Id corresponding to the DC driving voltage Vd is generated in the heater 430 of the EHC 400, and the heater 430 generates heat by the driving current Id. In response to the heat donation due to the heat generation, warming up of the three-way catalyst 420 is promoted, and the catalyst temperature Tc rises to the target catalyst temperature Tctag. Energization of the heater 430 through the PCU 500 is continued until the catalyst temperature Tc reaches the target catalyst temperature Tcttag.

  Here, the effect of this embodiment will be described visually with reference to FIG. FIG. 5 is a timing chart schematically showing the states of the battery 600 and the EHC 400 in the process of executing the battery charging control.

  In FIG. 5, the upper stage shows the time characteristic of the external power W that is the power supplied from the external power source 20, the middle stage shows the time characteristic of the target storage amount SOCtag of the battery 600, and the lower stage shows the time characteristic of the catalyst temperature Tc, Each is represented.

  It is assumed that the SOC of battery 600 is lower limit value SOCmin (SOCmin <SOCmax) for control before illustrated time T0. Here, when external power supply 20 and charging plug 700 are connected at time T0, charging of battery 600 is started in accordance with the battery charging control described above. At this point, the external power W becomes the illustrated value W0 required for charging the battery 600.

  At time T0, catalyst temperature Tc is equal to or higher than determination reference value Tcth, and target charge amount SOCtag is fixed at a maximum value SOCmax in control. On the other hand, in the soak state, the cooling of the three-way catalyst 420 proceeds with time, and at time T1, the catalyst temperature Tc reaches the determination reference value Tcth (see the white circle m1 in the drawing). Since the catalyst temperature Tc is still decreasing at this time, the target charge amount SOCtag corresponds to the storage amount correction amount f described earlier than the control maximum value SOCmax at the first determination timing after time T1. Get bigger.

  On the other hand, at the time T1, the storage amount SOC is still less than the maximum control value SOCmax (see the white circle m2 in the figure), and as described above, the target storage amount SOCtag is corrected almost simultaneously with the time T1, thereby storing the storage amount. At the time T2 when the SOC reaches the maximum control value SOCmax (see the white circle m3 in the figure), the target charged amount SOCtag is already larger than the maximum control value SOCmax. Therefore, energization of battery 600 is continued without changing the control state of relay circuit 800.

  As described above, the catalyst temperature Tc continues to decrease, and at time T2, is lower than the catalyst temperature at time T1 (see white circle m4 in the drawing). Here, at time T3, it is assumed that the decrease in the catalyst temperature Tc has ended and the catalyst temperature Tc has converged to Tc0 (Tc0 <Tcth) (see the white circle m5 in the drawing). Assuming that the target storage amount SOCtag determined by the catalyst temperature deviation ΔTc (in this case, Tatag−Tc0) corresponding to this catalyst temperature Tc0 is SOCmax1 (SOCmax1> SOCmax), the storage amount SOC at time T3 is less than SOCmax1. Therefore (see the white circle m6 in the figure), the energization of the battery 600 is ended at the time T4 (see the white circle m7 in the figure) when the storage amount SOC has reached SOCmax1.

  That is, according to the battery charge control according to the present embodiment, for the energization of the EHC 400 during the period from when the charged amount SOC reaches SOCmax at time T2 to when the charged amount SOC reaches SOCmax1 at time T4. The amount of electricity stored is raised, and the amount of electricity stored becomes larger than the original value by the indicated amount of increase ΔW.

  Here, it is assumed that energization of the EHC 400 is started to warm up the catalyst at the start timing of the hybrid vehicle 10 (not shown). At this time, the speed related to the decrease in the stored amount SOC of the battery 600 over time is slow enough that the decrease amount can be ignored at least within a routinely assumed soak time. The stored amount SOC of the battery 600 is SOCmax1. Is maintained.

  Here, in particular, the target charged amount SOCmax is increased by an amount necessary for the catalyst temperature Tc to reach the target catalyst temperature Tcttag from the current value. Electric power consumption corresponding to the amount corresponding to the increase in height ΔW is made, and the three-way catalyst 420 is warmed up. As a result, ideally, when the catalyst temperature Tc reaches the target catalyst temperature Tcttag, the storage amount SOC of the battery 600 returns to the control maximum value SOCmax. That is, when the EHC 400 is energized when the hybrid vehicle 10 is started, the charged amount SOC of the battery 600 is from the control target value SOCmax that is originally set so as to allow the hybrid vehicle 10 to travel appropriately. There is no decrease. Further, even if the value falls below the control target value SOCmax for some reason, the amount of reduction is clearly suppressed as compared with the case where the concept of the present invention is not applied. Therefore, it is extremely unlikely that the driving performance (for example, the EV traveling distance) of the hybrid vehicle 10 is lowered by taking out the electric power from the battery 600 in order to warm up the catalyst at the time of starting. The benefits associated with reducing emissions of the hybrid vehicle 10 due to some significant advancement in catalyst warm-up previously are enjoyed very effectively.

  Further, supplementally, when energization to the EHC 400 is performed simultaneously during the energization of the battery 600 (when the external power supply destination can be selectively switched between the battery 600 and the EHC 400, While the supply destination may be switched to the EHC side during the external power supply period), the catalyst warm-up can be suitably performed, but the rate of time-wise decrease in the catalyst temperature Tc after the end of catalyst heating is Considering that the amount of stored electricity is significantly higher than that of the SOC, it is difficult to avoid excessive power consumption. Such excessive power consumption should be avoided as much as possible in view of the fact that power resources are limited and should be respected, and in view of the significance of the existence of the hybrid vehicle 10. (I.e., when there is a reason that it can be determined that the engine 200 is required to be started in the near future) and before the engine is started, the catalyst is warmed up to suppress excessive power consumption and The practical advantage according to the present embodiment is great in that the emission can be suppressed while avoiding a significant decrease in the amount of power stored in the battery 600.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of a hybrid vehicle involving such a change. The apparatus is also included in the technical scope of the present invention.

1 is a schematic block diagram conceptually showing a configuration of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view conceptually and schematically illustrating a cross-sectional configuration of an engine provided in the hybrid vehicle of FIG. 1. FIG. 3 is a schematic cross-sectional view conceptually showing a cross-sectional configuration of EHC along the extension direction of the exhaust pipe in the engine of FIG. 2. It is a flowchart of the battery charge control performed by ECU. 5 is a timing chart for explaining states of a battery and an EHC in the execution process of the control of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Hybrid vehicle, 100 ... ECU, 200 ... Engine, 201 ... Cylinder, 203 ... Piston, 205 ... Crankshaft, 300 ... Power split mechanism, 400 ... EHC, 420 ... Three-way catalyst, 430 ... Heater, 500 ... PCU, 600 ... battery, 700 ... charge plug, 800 ... relay circuit.

Claims (4)

An internal combustion engine;
At least one electric motor functioning as a power source with the internal combustion engine;
A power storage means that functions as a power source for the electric motor and can be charged by external power supplied from an external power source;
A catalyst installed in an exhaust path of the internal combustion engine and capable of purifying exhaust of the internal combustion engine;
Heating means capable of heating the catalyst by energization using stored electric power stored in the power storage means;
A control device for a hybrid vehicle, comprising: energization means for performing the charging and energization,
A specifying means for specifying a catalyst temperature as a temperature of the catalyst;
Setting means for setting a target value of the amount of electricity stored in the electricity storage means based on the identified catalyst temperature;
A control device for a hybrid vehicle, comprising: control means for controlling the energization means so that the amount of stored electricity becomes the set target value during the supply period of the external power. The setting means sets the target value of the charged amount according to the deviation so that the magnitude of the deviation between the target value of the catalyst temperature and the specified catalyst temperature corresponds to an increase or decrease, respectively. The hybrid vehicle control device according to claim 1. The hybrid vehicle according to claim 2, wherein the setting unit sets the target value of the charged amount by correcting a reference value of the target value of the charged amount that is set in advance according to the deviation. Control device. The said control means controls the said electricity supply means so that the said electricity supply may be performed when the start input which should start the said hybrid vehicle is made. The control apparatus of the hybrid vehicle as described in 2.

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