JP2006112281A - Internal combustion engine, hybrid vehicle equipped with the same, and method for controlling internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of catalyst at a time of decrease of speed of an internal combustion engine and suppress unexpected increase of speed of the internal combustion engine. <P>SOLUTION: Catalyst deterioration suppressing control is prohibited (S160) when change quantity ΔNe of engine speed Ne exceeds a threshold ΔNref established with determining based on change quantity ΔNe of engine speed Ne whether an operation condition of the engine is under transient condition or not when engine speed is to be reduced while executing catalyst deterioration suppressing control for increasing intake air quantity for suppressing catalyst deterioration due to exposure of the catalyst to high temperature lean atmosphere. Consequently, racing of engine can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an internal combustion engine device, a hybrid vehicle equipped with the internal combustion engine device, and a control method for the internal combustion engine, and more particularly, to an internal combustion engine device having an internal combustion engine to which an exhaust gas purification device having a catalyst for purifying exhaust gas is attached. The present invention relates to a hybrid vehicle and a method for controlling such an internal combustion engine.

Conventionally, as this type of internal combustion engine device, one that raises the intake air amount when the rotational speed of the engine is suddenly reduced has been proposed (see, for example, Patent Document 1). When suddenly decreasing, fuel cut is prohibited and engine combustion is continued by controlling the idle speed control valve so that the minimum amount of intake air that can continue engine combustion is supplied to the engine. In this state, the number of revolutions is reduced to prevent catalyst deterioration due to exposure of the catalyst of the catalytic converter for purifying exhaust gas to a high temperature lean atmosphere.
JP-A-10-252532

  As described above, when the engine combustion is continued when the engine speed is suddenly reduced, the engine speed may not decrease or the engine speed may not be reduced due to variations in the learning value in the engine operating environment and engine operation control. May increase. In particular, when the configuration is applied to a hybrid vehicle that can freely change the operating point of the engine according to the running state, an increase in the engine speed cannot be suppressed and the engine may blow up. , The driver (operator) and the passenger will feel uncomfortable.

  INDUSTRIAL APPLICABILITY An internal combustion engine device, a hybrid vehicle equipped with the internal combustion engine device, and an internal combustion engine control method according to the present invention aim to prevent catalyst deterioration and reduce an unexpected increase in the internal combustion engine speed when the rotational speed of the internal combustion engine is decreased. For the purpose.

  The internal combustion engine device of the present invention, the hybrid vehicle equipped with the same, and the control method of the internal combustion engine employ the following means in order to achieve the above-mentioned object.

The internal combustion engine device of the present invention is
An internal combustion engine device to which an exhaust gas purification device having a catalyst for purifying exhaust gas is attached,
Intake air amount adjusting means for adjusting the intake air amount of the internal combustion engine;
Fuel injection means for performing fuel injection according to the intake air amount of the internal combustion engine;
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
When reducing the rotational speed of the internal combustion engine, the intake air amount adjusting means is configured to supply a deterioration prevention intake air amount for preventing deterioration of the catalyst to the internal combustion engine so that combustion of the internal combustion engine is continued. When the detected rate of change in the rotational speed of the internal combustion engine exceeds the threshold change rate, the catalyst deterioration prevention control is supplied to the internal combustion engine. A control unit at the time of decrease for controlling the intake air amount adjusting means and the fuel injection means so that the intake air amount to be controlled is limited;
It is a summary to provide.

  In this internal combustion engine device according to the present invention, when the rotational speed of the internal combustion engine is reduced, an intake air amount for preventing deterioration is supplied to the internal combustion engine in order to prevent deterioration of the catalyst of the exhaust purification device attached to the internal combustion engine. Then, the catalyst deterioration prevention control is performed to control the intake air amount adjusting means and the fuel injection means so that the combustion of the internal combustion engine is continued, and when the change rate of the rotational speed of the internal combustion engine exceeds the threshold change rate, the catalyst In the deterioration prevention control, the intake air amount adjusting means and the fuel injection means are controlled so that the intake air amount supplied to the internal combustion engine is limited. Thereby, it can suppress that the change rate of the rotation speed of an internal combustion engine blows up exceeding the change rate for threshold values. Of course, it is possible to prevent deterioration of the catalyst of the exhaust purification device.

  In such an internal combustion engine apparatus of the present invention, the decrease time control means performs control using the first rate of change as the threshold rate of change when the change of the operating state of the internal combustion engine is within a predetermined allowable change range. In addition, when the change in the operating state of the internal combustion engine is outside the allowable change range, the control unit may be a means for controlling using a second change rate larger than the first change rate. By so doing, it is possible to limit the amount of intake air supplied to the internal combustion engine in the catalyst deterioration prevention control according to changes in the operating state of the internal combustion engine. Note that a value of 0 can be used for the first rate of change. The internal combustion engine apparatus of the present invention having such an aspect includes intake air amount detection means for detecting the intake air amount of the internal combustion engine, and the decrease time control means is the intake air amount detected by the intake air amount detection means. When the change rate of the intake air amount is within a predetermined range, control is performed so that the change in the operating state of the internal combustion engine is within the allowable change range, and the change rate of the intake air amount detected by the intake air amount detection means is outside the predetermined range. Sometimes, it may be a means for controlling that the change in the operating state of the internal combustion engine is outside the allowable change range. By so doing, it is possible to limit the amount of intake air supplied to the internal combustion engine in the catalyst deterioration prevention control according to the rate of change of the intake air amount.

  In the internal combustion engine device of the present invention, the deterioration preventing intake air amount is an air amount obtained by raising the intake air amount with respect to a normal intake air amount, and the restriction of the intake air amount is the intake air amount. It can also be said that the increase in the amount of air is stopped.

  Furthermore, in the internal combustion engine device of the present invention, the catalyst deterioration prevention control may be control performed with an intake air amount at which an output torque from the internal combustion engine has a value of 0 as an upper limit. In this way, it is possible to suppress an excessive intake air amount from being supplied to the internal combustion engine.

The hybrid vehicle of the present invention
The internal combustion engine apparatus of the present invention according to any one of the above aspects having an internal combustion engine that can be operated regardless of the power required for the vehicle, that is, basically an exhaust purification apparatus having a catalyst for purifying exhaust gas is attached. An internal combustion engine device having an internal combustion engine, the intake air amount adjusting means for adjusting the intake air amount of the internal combustion engine, the fuel injection means for performing fuel injection according to the intake air amount of the internal combustion engine, and the internal combustion engine A rotational speed detection means for detecting the rotational speed of the engine, and an intake air amount for preventing deterioration for preventing the catalyst from being deteriorated when the rotational speed of the internal combustion engine is reduced, to the internal combustion engine; When the catalyst deterioration prevention control is performed to control the intake air amount adjusting means and the fuel injection means so that the combustion of the engine continues, and the detected change rate of the internal combustion engine speed exceeds the threshold change rate. An internal combustion engine system and a reduction time control means for controlling said fuel injection means and said intake air quantity adjusting means so that the intake air amount supplied to the internal combustion engine in the catalyst deterioration preventing control is limited to,
An electric motor capable of outputting driving power;
It is a summary to provide.

  Since the hybrid vehicle of the present invention includes the internal combustion engine device of the present invention according to any one of the above-described aspects, the effect exhibited by the internal combustion engine device of the present invention, for example, the rate of change in the rotational speed of the internal combustion engine is the threshold rate of change. The effect similar to the effect which can suppress that it blows over, the effect which can prevent deterioration of the catalyst of an exhaust gas purification apparatus, etc. can be show | played.

  In such a hybrid vehicle of the present invention, a part of the power of the internal combustion engine is connected to the output shaft of the internal combustion engine and a drive shaft connected to the axle, and input / output of electric power and power is used as the drive shaft. It can also be provided with output power power input / output means.

The internal combustion engine control method of the present invention includes:
A control method for an internal combustion engine equipped with an exhaust purification device having a catalyst for purifying exhaust,
When the rotational speed of the internal combustion engine is reduced, the deterioration prevention intake control for preventing deterioration of the catalyst is supplied to the internal combustion engine and the catalyst deterioration prevention control for continuing combustion of the internal combustion engine is executed. The gist is to control the intake air amount supplied to the internal combustion engine in the catalyst deterioration prevention control when the change rate of the rotational speed of the internal combustion engine exceeds a threshold change rate.

  In the control method for an internal combustion engine according to the present invention, when the rotational speed of the internal combustion engine is reduced, the intake air amount for preventing deterioration is used to prevent the deterioration of the catalyst of the exhaust purification device attached to the internal combustion engine. The amount of intake air supplied to the internal combustion engine in the catalyst deterioration prevention control when the rate of change in the engine speed exceeds the threshold rate change rate is executed. Therefore, it is possible to suppress the rate of change of the rotational speed of the internal combustion engine from exceeding the threshold rate of change and to prevent deterioration of the catalyst of the exhaust emission control device.

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

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an internal combustion engine device according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire power output apparatus.

  The engine 22 is configured as an internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and the air purified by an air cleaner 122 is passed through a throttle valve 124 as shown in FIG. Inhalation and gasoline are injected from the fuel injection valve 126 to mix the sucked air and gasoline. The mixture is sucked into the fuel chamber through the intake valve 128 and is explosively burned by an electric spark from the spark plug 130. Thus, the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is discharged to the outside air through a purifier 134 having a catalyst (three-way catalyst) 134b that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Is done.

The catalyst 134b of the purification device 134 is composed of an oxidation catalyst such as platinum (Pt) or palladium (Pd), a reduction catalyst such as rhodium (Rh), and a promoter such as ceria (CeO ₂ ). Then, CO and HC contained in the exhaust gas are purified by water (H ₂ O) and carbon dioxide (CO ₂ ) by the action of the oxidation catalyst, and NOx contained in the exhaust gas is nitrogen (N ₂ ) and oxygen by the action of the reduction catalyst. Purified to (O ₂ ). Such a catalyst 134b has a good balance between NOx adsorption / decomposition reaction by the reduction catalyst and oxidation reaction of HC and CO by the oxidation component generated at that time when the air-fuel ratio of the air-fuel mixture is in the so-called window region near the stoichiometric air-fuel ratio. It shows a high purification rate for all of HC, CO and NOx, and when exposed to a lean atmosphere at a high temperature (for example, 800 ° C. or higher), the oxidation catalyst and the reduction catalyst grow grains and the surface area decreases. It deteriorates and its purification function decreases.

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as an engine ECU) 24. The engine ECU 24 is configured as a microprocessor centered on the CPU 24a, and includes a ROM 24b that stores a processing program, a RAM 24c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 24a. . Signals from various sensors that detect the state of the engine 22 are input to the engine ECU 24 via an input port (not shown). For example, the engine ECU 24 has a crank position from a crank position sensor 140 that detects the rotational position of the crankshaft 26, a coolant temperature from a water temperature sensor 142 that detects the temperature of coolant in the engine 22, and a knock attached to the crankcase. A cam position for detecting a knock signal from the sensor 152, an intake air temperature from an intake air temperature sensor 123 provided at a subsequent stage of the air cleaner 122, an intake valve 128 for intake and exhaust to the combustion chamber, and a rotational position of a camshaft for opening and closing the exhaust valve A cam position from the sensor 144, a throttle position from the throttle valve position sensor 146 that detects the position of the throttle valve 124, an intake air amount from the vacuum sensor 148 that detects an intake air amount as a load of the engine 22, Air, such as oxygen signal from an oxygen sensor 135b attached to the downstream side of the catalytic converter 134 is input via the input port from an air-fuel ratio sensor 135a attached to the upstream side of the apparatus 134. Further, various control signals for driving the engine 22 are output from the engine ECU 24 via an output port (not shown). For example, the engine ECU 24 sends a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, a control signal to the ignition coil 138 integrated with the igniter, and the intake valve 128. A control signal to the variable valve timing mechanism 150 whose opening / closing timing can be changed is output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. .

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. The charging / discharging operation mode for driving and controlling the motor MG1 and the motor MG2 so that the motor MG2 is output to the ring gear shaft 32a. The power corresponding to the required power is output from the motor MG2 to the ring gear shaft 32a while the operation of the engine 22 is stopped or the engine 22 is idling. There is a motor operation mode for controlling the operation. Since the torque conversion operation mode is not accompanied by charging / discharging of the battery 50 in the charge / discharge operation mode, the hybrid vehicle 20 of the embodiment travels in the charge / discharge operation mode and the motor operation mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly when the engine is switched from traveling in the charge / discharge operation mode to traveling in the motor operation mode, or when the accelerator pedal 83 that has been depressed in the charge / discharge operation mode is turned off. The control of the engine 22 when the rotational speed Ne of 22 is rapidly reduced will be described. At this time, catalyst deterioration suppression control is performed in which fuel cut is prohibited and combustion of the engine 22 is continued so that the catalyst 134b of the purification device 134 is not exposed to a high-temperature lean atmosphere. In this catalyst deterioration suppression control, a raised air amount set in advance as a minimum intake air amount for continuing combustion in the engine 22 is added to the intake air amount, and the engine 22 is not misfired from the combustion state of the engine 22. Thus, the opening degree (throttle opening degree) TH of the throttle valve 124 is controlled so that the torque output from the engine 22 becomes a value of 0 or less.

  The engine ECU 24 repeatedly executes the catalyst deterioration suppression control prohibition determination process while executing such catalyst deterioration suppression control. FIG. 3 is a flowchart illustrating an example of a catalyst deterioration suppression control prohibition determination routine. When this routine is executed, the engine ECU 24 first executes a process of inputting data necessary for the determination process such as the rotational speed Ne of the engine 22 and the intake air amount KL from the vacuum sensor 148 (step S100). Here, the rotation speed Ne of the engine 22 is calculated by using the crank position detected by the crank position sensor 140 in a rotation speed detection routine (not shown), and the value written in the RAM 24c is input.

  When the data is input in this way, the rotational speed change amount ΔNe is calculated by subtracting the rotational speed Ne of the engine 22 input this time from the rotational speed Ne of the engine 22 input this time when the routine was executed last time and The air change amount ΔKL is calculated by subtracting the intake air amount KL input this time from the intake air amount KL input at the time of execution (step S110). Here, since the rotation speed change amount ΔNe is the rotation speed change amount per activation interval time of this routine, the average change rate of the rotation speed per activation interval time is obtained by dividing by the activation interval time. Now, since the startup interval time of this routine is constant, the rotational speed change amount ΔNe can also be considered as the rate of change of the rotational speed Ne. Similarly, the air change amount ΔKL can also be considered as the change rate of the intake air amount KL.

  Subsequently, it is determined whether or not the air change amount ΔKL is within a transient determination range set by the threshold value ΔKL1 and the threshold value ΔKL2 (step S120). Here, the threshold value ΔKL1 and the threshold value ΔKL2 are used to determine whether or not the operating state of the engine 22 is in a transient state. The threshold value ΔKL1 is set as a negative value, and the threshold value ΔKL2 is set as a positive value. . When the air change amount ΔKL is within the transient determination range including the value 0, it is determined that the operation state of the engine 22 is not in the transient state, and when the air change amount ΔKL is outside the transient determination range, the operation state of the engine 22 is Judged to be in a transient state. Whether or not the operating state of the engine 22 is in a transient state can be determined based on the air change amount ΔKL. The engine 22 has a small change in the operating state when the change in the intake air amount KL is small, and the intake air amount KL. This is based on the fact that the change in the driving state is large when the change in is large. When the air change amount ΔKL is within the transient determination range, it is determined that the operating state of the engine 22 is not a transient state, and the set value ΔN1 (value 0 in the embodiment) is set to the threshold value ΔNref (step S130). When the amount ΔKL is outside the transient determination range, it is determined that the operating state of the engine 22 is in a transient state, and the set value ΔN2 set as a value slightly larger than the set value ΔN1 is set as the threshold value ΔNref (step S140). Changing the value set for the threshold value ΔNref according to the operating state of the engine 22 will be described later.

  Then, the engine speed change amount ΔNe is compared with the threshold value ΔNref (step S150). When the engine speed change amount ΔNe is equal to or smaller than the threshold value ΔNref, the catalyst deterioration suppression control prohibition determination routine is ended, and the engine speed change amount ΔNe becomes the threshold value ΔNref. Is exceeded (step S160), the catalyst deterioration suppression control prohibition determination routine is terminated. When the catalyst deterioration suppression control is prohibited, the increase in the intake air amount is stopped, so that the rotational speed Ne of the engine 22 rapidly decreases. In the embodiment, the threshold value ΔNref is input with a setting value ΔN1 having a value of 0 or a setting value ΔN2 that is slightly larger than this. Therefore, when the rotational speed change amount ΔNe exceeds the threshold value ΔNref, the rotational speed Ne of the engine 22 increases. It becomes a state. Therefore, in the embodiment, when the rotation speed Ne of the engine 22 increases while the engine 22 continues to burn by performing the catalyst deterioration suppression control, the catalyst deterioration suppression control is performed. It prohibits and suppresses the increase in the rotational speed Ne of the engine 22 and rapidly decreases the rotational speed Ne of the engine 22. In the catalyst deterioration suppression control of the embodiment, as described above, the increased air amount for continuing combustion in the engine 22 is added to the intake air amount, and the engine 22 is output from the engine 22 so as not to misfire from the combustion state of the engine 22. Since the throttle opening TH is controlled so that the torque to be applied becomes 0 or less, normally, the rotational speed Ne of the engine 22 does not increase. However, there are cases where the rotational speed Ne of the engine 22 increases due to variations in the learning values used for engine 22 operation control such as fuel injection control and ignition control, and variations in engine friction. In the embodiment, by prohibiting the catalyst deterioration suppression control when such an increase in the rotational speed Ne of the engine 22 occurs, the increase in the rotational speed Ne of the engine 22 that has been increasing is suppressed and the rotational speed Ne is rapidly decreased. To make it happen. The determination of the increase in the rotational speed Ne of the engine 22 is more erroneous when the operation state of the engine 22 is unstable than when the operation state of the engine 22 is stable. In the embodiment, in order to reduce such erroneous determinations, when the operating state of the engine 22 is not in a transient state, the set value ΔN1 set to the value 0 is set to the threshold value ΔNref to determine the increase in the rotational speed Ne, and the engine When the operation state 22 is in a transient state, a setting value ΔN2 slightly larger than the setting value ΔN1 is set as the threshold value ΔNref, and an increase in the rotational speed Ne is determined. Thereby, it is possible to more appropriately determine the increase in the rotational speed Ne of the engine 22. Stopping the increase in the intake air amount is performed by rate processing or the like because the intake air amount KL changes suddenly.

  FIG. 4 shows the amount of air raised when the rotation speed Ne is increased and the catalyst deterioration suppression control is prohibited when the rotation speed Ne of the engine 22 is decreased while the catalyst deterioration suppression control is executed, and the rotation speed Ne of the engine 22. It is explanatory drawing which shows typically an example of the time change of rotational speed variation | change_quantity (DELTA) Ne, intake air amount KL, and air variation | change_quantity (DELTA) KL. As shown in the figure, the accelerator pedal 83 that was depressed at time T1 is turned off, and control for reducing the rotational speed Ne of the engine 22 is started with the execution of the catalyst deterioration suppression control. Normally, the rotational speed Ne of the engine 22 is quickly reduced, but there may be a case where the rotational speed Ne of the engine 22 is not rapidly reduced due to variations in learning values and variations in engine friction. Then, at time T2 when the rotational speed Ne of the engine 22 is slightly increased, the rotational speed change amount ΔNe exceeds the threshold value ΔNref set to the value 0, and the catalyst deterioration suppression control is prohibited. As a result, the increase in the intake air amount KL is stopped, and the rotational speed Ne of the engine 22 rapidly decreases.

  According to the hybrid vehicle 20 of the embodiment described above, the catalyst deterioration suppression control is prohibited when the rotation speed Ne of the engine 22 increases while attempting to decrease the rotation speed Ne of the engine 22 while executing the catalyst deterioration suppression control. Therefore, it is possible to suppress the engine 22 from blowing up. In addition, since the threshold value ΔNref for determining the increase in the rotational speed Ne of the engine 22 is changed depending on whether or not the operating state of the engine 22 is in a transient state, the increase in the rotational speed Ne of the engine 22 is more appropriately determined. Can do. Further, since whether or not the operating state of the engine 22 is in a transient state is determined based on the amount of change in the intake air amount KL, it is possible to more appropriately determine whether or not the operating state of the engine 22 is in a transient state. . Of course, since the catalyst deterioration suppression control is performed, the deterioration of the catalyst 134b of the purifier 134 can be suppressed.

  Here, in the embodiment, the throttle valve 124, the throttle motor 136, and the throttle valve position sensor 146 correspond to intake air amount adjustment means, the fuel injection valve 126 corresponds to fuel injection means, and the crank position from the crank position sensor 140. The CPU 24a of the engine ECU 24 that calculates the rotational speed Ne of the engine 22 based on the above corresponds to the rotational speed detection means, and executes the catalyst deterioration suppression control and also executes the catalyst deterioration suppression control prohibition determination routine of FIG. Corresponds to the control means when decreasing.

  In the hybrid vehicle 20 of the embodiment, it is determined whether or not the operating state of the engine 22 is in a transient state based on the change amount of the intake air amount KL (air change amount ΔKL), but the parameter other than the air change amount ΔKL is set. Based on this, it may be determined whether or not the operating state of the engine 22 is in a transient state.

  In the hybrid vehicle 20 of the embodiment, the threshold value ΔNref for determining the increase in the rotational speed Ne of the engine 22 is changed depending on whether or not the operating state of the engine 22 is in a transitional state, but regardless of the operating state of the engine 22. Instead, the increase in the rotational speed Ne of the engine 22 may be determined based on a certain threshold value ΔNref. In this case, the threshold value ΔNref is not limited to the value 0, and may be a value slightly larger than the value 0 or a value slightly smaller than the value 0.

  In the hybrid vehicle 20 of the embodiment, the catalyst deterioration suppression control is prohibited when the rotation speed Ne of the engine 22 is increased while the rotation speed Ne of the engine 22 is being decreased while performing the catalyst deterioration suppression control. Instead of prohibiting the catalyst deterioration suppression control, the amount of raised air in the catalyst deterioration suppression control may be limited. For example, when the rotational speed Ne of the engine 22 increases, the catalyst deterioration suppression control may be executed with the amount of air obtained by multiplying the amount of increased air by a correction coefficient smaller than 1 as the amount of increased air.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 5) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided. Further, any configuration of the vehicle may be used as long as the vehicle can drive the engine 22 regardless of the power required for the vehicle.

  In the embodiment, the hybrid vehicle 20 on which the internal combustion engine device of the present invention is mounted has been described. However, the internal combustion engine device of the present invention is not limited to the one mounted on the hybrid vehicle 20, and vehicles other than cars and ships , It is good also as what is mounted in moving bodies, such as an aircraft, and does not matter as what is built in the equipment which does not move.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in an internal combustion engine device manufacturing industry, an automobile manufacturing industry, and the like.

1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an internal combustion engine device according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 5 is a flowchart showing an example of a catalyst deterioration suppression control prohibition determination routine executed by an engine ECU 24. It is explanatory drawing which shows typically an example of time changes, such as the amount of raising air, and the rotation speed Ne of the engine 22, when the rotation speed Ne increases and catalyst deterioration suppression control is prohibited. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35, reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronics Control unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b, 64a, 64b drive wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 122 air cleaner, 123 intake air temperature sensor, 124 throttle valve, 126 fuel Injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purifier, 134b Catalyst, 135a Air-fuel ratio sensor, 135b Oxygen sensor, 136 Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 Water temperature sensor, 144 Cam position Sensor, 146 throttle valve position sensor, 148 vacuum sensor, 150 variable valve timing mechanism, 152 knock sensor 230 rotor motor, 232 inner rotor, 234 outer rotor, MG1, MG2 motor.

Claims (9)

An internal combustion engine device having an internal combustion engine to which an exhaust gas purification device having a catalyst for purifying exhaust gas is attached,
Intake air amount adjusting means for adjusting the intake air amount of the internal combustion engine;
Fuel injection means for performing fuel injection according to the intake air amount of the internal combustion engine;
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
When reducing the rotational speed of the internal combustion engine, the intake air amount adjusting means is configured to supply a deterioration prevention intake air amount for preventing deterioration of the catalyst to the internal combustion engine so that combustion of the internal combustion engine is continued. When the detected rate of change in the rotational speed of the internal combustion engine exceeds the threshold change rate, the catalyst deterioration prevention control is supplied to the internal combustion engine. A control unit at the time of decrease for controlling the intake air amount adjusting means and the fuel injection means so that the intake air amount to be controlled is limited;
An internal combustion engine device comprising:   The decrease time control means controls when the change in the operating state of the internal combustion engine is within a predetermined allowable change range, using the first change rate as the threshold change rate, and controls the operating state of the internal combustion engine. 2. The internal combustion engine device according to claim 1, wherein the control unit uses a second rate of change larger than the first rate of change when the change is outside the allowable change range.   The internal combustion engine device according to claim 2, wherein the first rate of change is a value of zero. An internal combustion engine device according to claim 2 or 3,
An intake air amount detecting means for detecting an intake air amount of the internal combustion engine;
The decrease time control means controls that the change in the operating state of the internal combustion engine is within the allowable change range when the change rate of the intake air quantity detected by the intake air quantity detection means is within a predetermined range, An internal combustion engine device that controls that the change in the operating state of the internal combustion engine is outside the allowable change range when the change rate of the intake air amount detected by the intake air amount detection means is outside the predetermined range. An internal combustion engine device according to any one of claims 1 to 4,
The deterioration preventing intake air amount is an air amount obtained by raising the intake air amount with respect to the normal intake air amount,
The restriction of the intake air amount is to stop raising the intake air amount.   The internal combustion engine apparatus according to any one of claims 1 to 5, wherein the catalyst deterioration prevention control is control performed with an intake air amount at which an output torque from the internal combustion engine has a value of 0 as an upper limit. The internal combustion engine device according to any one of claims 1 to 6, further comprising an internal combustion engine that can be operated regardless of power required for the vehicle;
An electric motor capable of outputting driving power;
A hybrid car with   Power power input / output means connected to the output shaft of the internal combustion engine and a drive shaft connected to the axle, and capable of outputting a part of the power of the internal combustion engine to the drive shaft with input / output of power and power The hybrid vehicle according to claim 7. A control method for an internal combustion engine equipped with an exhaust purification device having a catalyst for purifying exhaust,
When the rotational speed of the internal combustion engine is reduced, the deterioration prevention intake control for preventing deterioration of the catalyst is supplied to the internal combustion engine and the catalyst deterioration prevention control for continuing combustion of the internal combustion engine is executed. A control method for an internal combustion engine, wherein when the rate of change of the rotational speed of the internal combustion engine exceeds a threshold rate of change, the amount of intake air supplied to the internal combustion engine is controlled in the catalyst deterioration prevention control.

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