JP7581981B2 - Hybrid Vehicles - Google Patents

Description

The present invention relates to a hybrid vehicle equipped with an engine and a motor.

Conventionally, hybrid vehicles of this type have been proposed that include an engine and a motor (see, for example, Patent Document 1). The engine outputs power for driving. The motor inputs and outputs power to the engine output shaft. In this vehicle, when a catalyst warm-up request is made, catalyst warm-up control is executed in which the motor feedback-controls the engine speed while retarding the engine ignition timing. Then, when the motor output exceeds a predetermined upper limit during catalyst warm-up control, the amount of retardation of the ignition timing is reduced. This prevents engine misfires.

JP 2003-214308 A

In the above-mentioned hybrid vehicle, in order to prevent deterioration of engine combustion, it is conceivable to control the engine so that when the engine is idled during catalyst warm-up control, the ignition timing of the engine is a second ignition timing different from the first ignition timing, which is the ignition timing when the engine is idled off and operated under load. When transitioning from idle on to idle off or from idle off to idle on, it is recognized as an important issue to appropriately change the ignition timing to prevent deterioration of engine combustion.

The primary objective of the hybrid vehicle of the present invention is to prevent deterioration of engine combustion.

The hybrid vehicle of the present invention employs the following means to achieve the above-mentioned main objective.

The hybrid vehicle of the present invention is
an engine equipped with a purification device having a purification catalyst;
a motor capable of inputting and outputting power to and from an output shaft of the engine;
a control device which, when a catalyst warm-up request for warming up the purification catalyst is made, controls the engine so that the ignition timing of the engine becomes a first ignition timing for promoting warm-up of the engine while feedback-controlling the engine speed by the motor during idle-off when the engine is operated under load, and controls the engine so that the ignition timing of the engine becomes a second ignition timing different from the first ignition timing and the engine speed becomes an idle speed while controlling the motor with a torque command of a value of 0 during idle-on when the engine is operated under idle;
A hybrid vehicle comprising:
The control device includes:
When the catalyst warm-up request is made,
feedback control an ignition timing of the engine using an integral term calculated using the torque of the motor when the engine is in the idle-off state and a combustion deterioration condition of the engine based on the torque of the motor is established;
feedback control an ignition timing of the engine using an integral term calculated using the engine speed when the engine is in the idle-on state and a combustion deterioration condition of the engine based on the engine speed is satisfied;
When transitioning from the idle-on state to the idle-off state, the integral term at the time of the idle-on state before transitioning to the idle-off state is stored, and when the idle-on state is subsequently reached, the ignition timing of the engine is controlled using the integral term at the time of the idle-on state that has been stored;
When the idle-off state is changed to the idle-on state, the integral term at the time of the idle-off state before the idle-on state is changed is stored, and when the idle-off state is subsequently changed, the ignition timing of the engine is controlled using the integral term at the time of the idle-off state that has been stored.
The gist of the present invention is as follows.

In the hybrid vehicle of the present invention, when a catalyst warm-up request is made, when the engine is in an idle-off state and the engine combustion deterioration condition based on the torque of the motor is satisfied, the engine ignition timing is feedback-controlled using an integral term calculated using the torque of the motor, and when the engine is in an idle-on state and the engine combustion deterioration condition based on the engine speed is satisfied, the engine ignition timing is controlled using an integral term calculated using the engine speed. When the engine is in an idle-on state and the engine combustion deterioration condition based on the engine speed is satisfied, the engine ignition timing is controlled using an integral term calculated using the engine speed. When the engine is in an idle-on state and the engine combustion deterioration condition based on the engine speed is satisfied, the engine ignition timing is controlled using an integral term calculated using the engine speed. When the engine is in an idle-on state and the engine combustion deterioration condition based on the engine speed is satisfied, the engine ignition timing is controlled using an integral term calculated using the engine speed. When the engine is in an idle-off state and the engine combustion deterioration condition based on the engine speed is satisfied, the engine ignition timing is feedback-controlled using an integral term calculated using different parameters at idle-off and idle-on. Therefore, when the engine transitions from idle off to idle on or from idle on to idle off, the integral term changes suddenly, making it impossible to control the ignition timing appropriately, and the engine combustion state may deteriorate. In the present invention, when the engine transitions from idle on to idle off, the integral term at idle on before the transition to idle off is stored, and when the engine transitions to idle on thereafter, the engine ignition timing is controlled using the integral term at idle on that has been stored, and when the engine transitions from idle off to idle on, the integral term at idle off before the transition to idle on is stored, and when the engine transitions to idle off thereafter, the engine ignition timing is controlled using the integral term at idle off that has been stored, thereby suppressing a sudden change in the integral term when the engine transitions from idle on to idle off or from idle on to idle off. As a result, deterioration of engine combustion can be suppressed.

1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an internal combustion engine control device according to an embodiment of the present invention; FIG. 2 is a diagram showing an outline of the configuration of an engine 22. 4 is a flowchart showing an example of a first ignition timing setting routine executed by an HVECU 70. 4 is a flowchart showing an example of a second ignition timing setting routine executed by an HVECU 70. 4 is a flowchart showing an example of a transition point ignition timing setting routine executed by an HVECU 70. 10 is an explanatory diagram for illustrating an example of time changes in the engine speed Ne and motor torque Tm1 of the engine 22 in an idle state, and the integral term Ion and integral term Ioff stored in a RAM. FIG.

Next, we will explain how to implement the present invention using examples.

Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an internal combustion engine control device as an embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of an engine 22. As shown in Figure 1, the hybrid vehicle 20 of the embodiment includes the engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel, or the like as fuel. As shown in FIG. 2, the engine 22 draws in air purified by the air cleaner 122 into the intake pipe 123, passes it through the throttle valve 124 and the surge tank 125, and injects fuel from the fuel injection valve 126 downstream of the surge tank 125 of the intake pipe 123 to mix the air and fuel. The engine 22 then draws this mixture into the combustion chamber 129 through the intake valve 128, and explosively burns the intake mixture with an electric spark from the spark plug 130. The reciprocating motion of the piston 132, which is pushed down by the energy of this explosive combustion, is converted into the rotational motion of the crankshaft 26. The exhaust gas discharged from the combustion chamber 129 into the exhaust pipe 134 through the exhaust valve 133 is discharged into the outside air through the purification device 136. Each purification device 136 has a purification catalyst (three-way catalyst) 136a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust.

The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it also has a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port.

Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via input ports. Examples of signals input to the engine ECU 24 include the crank angle θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26 of the engine 22, and the cooling water temperature Tw from the water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. In addition, the cam position θca from the cam position sensor 144 that detects the rotational position of the intake camshaft that opens and closes the intake valve 128 and the exhaust camshaft that opens and closes the exhaust valve 133 can also be mentioned. In addition, the throttle opening TH from the throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air volume Qa from the air flow meter 148 attached to the intake pipe 123, the intake air temperature Ta from the temperature sensor 149 attached to the intake pipe 123, and the surge pressure Ps from the pressure sensor 150 attached to the surge tank 125 can also be mentioned. In addition, examples include the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 attached upstream of the purification device 136 in the exhaust pipe 134, and the detected air-fuel ratio AFd from the downstream air-fuel ratio sensor 154 attached downstream of the purification device 136 in the exhaust pipe 134.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. Examples of signals output from the engine ECU 24 include a drive control signal to the throttle motor 124b that adjusts the position of the throttle valve 124, a drive control signal to the fuel injection valve 126, and a control signal to the ignition plug 130.

The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates the volumetric efficiency KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 148 and the rotation speed Ne of the engine 22.

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

Motor MG1 is configured, for example, as a synchronous generator motor, and as described above, its rotor is connected to the sun gear of planetary gear 30. Motor MG2 is configured, for example, as a synchronous generator motor, and its rotor is connected to drive shaft 36. Inverters 41, 42 are used to drive motors MG1, MG2 and are connected to battery 50 via power line 54. Motors MG1, MG2 are rotated by motor electronic control unit (hereinafter referred to as "motor ECU") 40 controlling the switching of multiple switching elements (not shown) of inverters 41, 42.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. Examples of signals input to the motor ECU 40 include the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, the phase currents Iu1 and Iv1 of the motor MG1 from the current sensors 41a and 41b that detect the phase currents flowing in the phases of the motor MG1, and the phase currents Iu2 and Iv2 of the motor MG2 from the current sensors that detect the phase currents flowing in the phases of the motor MG2. The motor ECU 40 outputs switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electrical angles θe1, θe2 and rotation speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position sensors 43, 44.

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

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor 51a attached between the terminals of the battery 50, the battery current Ib of the battery 50 from a current sensor 51b attached to the output terminal of the battery 50, and the temperature Tb of the battery 50 from a temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the power storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The power storage ratio SOC is the ratio of the capacity of the power that can be discharged from the battery 50 to the total capacity of the battery 50.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81. Other examples include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

The hybrid vehicle 20 of the embodiment thus configured runs in an electric driving mode (EV driving mode) in which the vehicle runs without the engine 22 operating, or in a hybrid driving mode (HV driving mode) in which the vehicle runs with the engine 22 operating.

In the EV driving mode, the HVECU 70 first sets the required torque Td* required for driving (required of the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V. Next, the HVECU 70 sets the torque command Tm1* of the motor MG1 to a value of 0, sets the torque command Tm2* of the motor MG2 so that the required torque Td* is output to the drive shaft 36, and transmits the set torque commands Tm1* and Tm2* of the motors MG1 and MG2 to the motor ECU 40. The motor ECU 40 performs switching control of the multiple switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

In the HV driving mode, the HVECU 70 first sets the required torque Td* in the same manner as in the EV driving mode. Next, the required torque Td* is multiplied by the rotation speed Nd of the drive shaft 36 to calculate the required power Pd* required for driving, and the required power Pe* required for the engine 22 is calculated by subtracting the charge/discharge required power Pb* of the battery 50 (a positive value when discharging from the battery 50) from the required power Pd*. Here, as the rotation speed Nd of the drive shaft 36, for example, the rotation speed Nm2 of the motor MG2 or a rotation speed obtained by multiplying the vehicle speed V by a conversion coefficient is used. Then, the target rotation speed Ne* and target torque Te* of the engine 22 are set so that the required power Pe* is output from the engine 22 and the required torque Td* is output to the drive shaft 36. Furthermore, a torque command Tm1* for the motor MG1 is set so that the rotation speed Ne of the engine 22 is feedback-controlled by the motor MG1 so that the rotation speed Ne of the engine 22 becomes the target rotation speed Ne*, and a torque command Tm2* for the motor MG2 is set so that the required torque Td* is output to the drive shaft 36. The target rotation speed Ne* and target torque Te* of the engine 22 are then sent to the engine ECU 24, and the torque commands Tm1* and Tm2* of the motors MG1 and MG2 are sent to the motor ECU 40. The engine ECU 24 performs intake air amount control, fuel injection control, ignition control, etc. for the engine 22 so that the engine 22 is operated based on the target rotation speed Ne* and target torque Te*. The control of the motors MG1 and MG2 (inverters 41 and 42) by the motor ECU 40 has been described above.

Next, we will explain the operation of the hybrid vehicle 20 of this embodiment, particularly the operation when warming up the purification catalyst 136a of the engine 22.

In the hybrid vehicle 20 of the embodiment, when the temperature of the purification catalyst 136a of the engine 22 is below a predetermined temperature (e.g., 350°C, 400°C, 450°C, etc.) during HV driving, and a catalyst warm-up request is made to warm up the purification catalyst 136a, the following control is executed.

When the catalyst warm-up request is made and the engine 22 is operated under load, such as when the required power Pe* is equal to or greater than 0, the target rotation speed Ne* and target torque Te* of the engine 22 and the torque commands Tm1* and Tm2* of the motors MG1 and MG2 are set in the same manner as the control during HV driving described above. Then, the target ignition timing Tf* is set by a first ignition timing setting routine described later. The target rotation speed Ne*, target torque Te*, and target ignition timing Tf* of the engine 22 are transmitted to the engine ECU 24. The torque commands Tm1* and Tm2* of the motors MG1 and MG2 are transmitted to the motor ECU 40. The engine ECU 24 performs intake air volume control, fuel injection control, ignition control, etc. of the engine 22 so that the engine 22 is operated based on the received target rotation speed Ne*, target torque Te*, and target ignition timing Tf*. The motor ECU 40 controls the inverters 41 and 42 as described above. That is, when the engine 22 is operated under load, the motor MG1 feedback controls the engine 22 rotation speed Ne.

Figure 3 is a flowchart showing an example of a first ignition timing setting routine executed by the HVECU 70. The first ignition timing setting routine is repeatedly executed by a CPU (not shown) of the HVECU 70 when the engine 22 is operated under load if a catalyst warm-up request is made.

When the first ignition timing setting routine is executed, the CPU of the HVECU 70 executes a process to input the phase currents Iu1 and Iv1 of the motor MG1 (step S100). The phase currents Iu1 and Iv1 are detected by the current sensors 41a and 41b and are input via communication with the motor ECU 40.

Next, the motor torque Tm1 is set as the torque output from the motor MG1 based on the input phase currents Iu1 and Iv1 (step S110). In this setting, the relationship between the phase currents Iu1 and Iv1 and the output torque output from the motor MG1 is previously determined as a first relationship, and when the phase currents Iu1 and Iv1 are given, the output torque derived from the phase currents Iu1 and Iv1 and the first relationship is set as the motor torque Tm1.

When the motor torque Tm1 is set, the motor torque Tm1 set when this routine was executed last time (last Tm1) is subtracted from the motor torque Tm1 and the torque change amount ΔTm1 is set (step S120), and it is determined whether the torque change amount ΔTm1 is equal to or less than the threshold value dtm1ref (step S130). The threshold value dtm1ref is a threshold value for determining whether the torque output from the motor MG1 has significantly decreased, and is set as a negative value. When the combustion state of the engine 22 deteriorates, the torque output from the engine 22 decreases significantly, and therefore the output torque of the motor MG1, which feedback controls the rotation speed Ne of the engine 22, also decreases significantly. Therefore, when the output torque of the motor MG1 decreases significantly, it is considered that the combustion state of the engine 22 has deteriorated. Therefore, step S130 is a process for determining whether a combustion deterioration condition, which is a condition for the deterioration of the combustion state of the engine 22, is satisfied.

When the torque change amount ΔTm1 is greater than the threshold value dtm1ref in step S130, it is determined that the combustion deterioration condition is not satisfied, and the engine 22 target ignition timing Tf* is set to the most retarded angle Tl (step S140), the target ignition timing Tf* is transmitted to the engine ECU 24 (step S160), and the first ignition timing setting routine is terminated. The most retarded angle Tl in step S140 is the latest timing (timing) within a range that is predetermined as the range of ignition timing that can be set for the engine 22. The engine ECU 24, which has received the target ignition timing Tf*, controls the spark plug 130 to ignite at the target ignition timing Tf* (most retarded angle Tl) (so that the ignition timing becomes the target ignition timing Tf*). In this way, by setting the ignition timing to the most retarded angle Tl, the purification catalyst 136a can be warmed up.

When the torque change amount ΔTm1 is equal to or less than the threshold value dtm1ref in step S130, it is determined that the combustion deterioration condition is satisfied, and the target ignition timing Tf* is set using the torque command Tm1* set as the target ignition timing Tf* when this routine was executed last time, the motor torque Tm1 set in step S110, and the following equation (1) (step S150). In equation (1), the second term is a proportional term in the feedback control of the ignition timing of the engine 22 to bring the motor torque Tm1 closer to the torque command Tm1*. "Kp1" is the gain of the proportional term. The third term is an integral term in the feedback control of the ignition timing of the engine 22. "Ki1" is the gain of the integral term.

Tf* = previous Tf* + Kp1 (Tm1*-Tm1) + Ki1 ∫ (Tm1*-Tm1) dt... (1)

Next, the second term of the formula (1) is stored in a RAM (not shown) as a proportional term Poff, and the third term is stored in a RAM (not shown) as an integral term Ioff (step S160), and the target ignition timing Tf* is sent to the engine ECU 24 (step S170), and the first ignition timing setting routine is terminated. In step S160, when the proportional term Poff and the integral term Ioff are already stored in the RAM, the proportional term Poff and the integral term Ioff of step S160 are overwritten on the stored proportional term Poff and the integral term Ioff. Therefore, the proportional term Poff and the integral term Ioff last set before transitioning from idle off to idle on are stored in the RAM. The engine ECU 24, which has received the target ignition timing Tf* in step S170, controls the ignition plug 130 so that it ignites at the target ignition timing Tf* (so that the ignition timing becomes the target ignition timing Tf*). This control can prevent deterioration of combustion in the engine 22.

When a catalyst warm-up request is made and the engine 22 is idled with the required power Pe* at a value of 0, the torque command Tm1* of the motor MG1 is set to a value of 0. Then, the torque command Tm2* of the motor MG2 is set so that the required torque Td* is output to the drive shaft 36. The torque commands Tm1* and Tm2* of the motors MG1 and MG2 are sent to the motor ECU 40. The motor ECU 40 controls the inverters 41 and 42 as described above. Then, the target ignition timing Tf* of the engine 22 is set by a second ignition timing setting routine described later. Then, the ignition plug 130 is controlled so that ignition occurs at the target ignition timing Tf* (so that the ignition timing becomes the target ignition timing Tf*), and the intake air amount control and fuel injection control of the engine 22, except for the ignition control of the engine 22, are performed so that the engine 22 idles (operates independently) at a predetermined idle speed Nidl.

Figure 4 is a flowchart showing an example of a second ignition timing setting routine executed by the HVECU 70. The second ignition timing setting routine is repeatedly executed by a CPU (not shown) of the HVECU 70 when the engine 22 is idling if a catalyst warm-up request is made.

When the second ignition timing setting routine is executed, the CPU of the HVECU 70 executes a process to input the rotation speed Ne of the engine 22 (step S200). The rotation speed Ne is calculated by the engine ECU 24 and input via communication.

Next, the rotation speed change amount ΔNe is set to a value obtained by subtracting the rotation speed Ne input the previous time this routine was executed from the input rotation speed Ne (step S210), and it is determined whether the rotation speed change amount ΔNe is equal to or less than a threshold value dNeref (step S220). The threshold value dNeref is a threshold value for determining whether the rotation speed Ne of the engine 22 has decreased significantly, and is set as a negative value. If the combustion state of the engine 22 deteriorates while the engine 22 is idling, the rotation speed Ne of the engine 22 decreases. Therefore, step S220 is a process for determining whether a combustion deterioration condition, which is a condition for the deterioration of the combustion state of the engine 22, is established.

When the rotation speed change amount ΔNe is greater than the threshold value dNeref in step S220, it is determined that the combustion deterioration condition is not satisfied, and the engine 22 target ignition timing Tf* is set to a predetermined timing Ta that is more advanced than the most retarded angle Tl (earlier than the most retarded angle Tl) (step S230), the target ignition timing Tf* is transmitted to the engine ECU 24 (step S250), and the second ignition timing setting routine is terminated. The predetermined timing Ta is an ignition timing that is predetermined as the ignition timing when the engine 22 is operating at idle. The engine ECU 24, which has received the target ignition timing Tf*, controls the ignition plug 130 so that it ignites at the target ignition timing Tf* (predetermined timing Ta) (so that the ignition timing becomes the target ignition timing Tf*). In this way, by setting the ignition timing to the predetermined timing Ta, the purification catalyst 136a can be warmed up while the engine 22 is operating at idle.

When the rotation speed change amount ΔNe is equal to or less than the threshold value dNeref in step S220, it is determined that the combustion deterioration condition is satisfied, and the target ignition timing Tf* is set using the target ignition timing Tf* and the idle rotation speed Nidl from the previous execution of this routine, the rotation speed Ne of the engine 22 input in step S200, and the following equation (2) (step S240). In equation (2) in step S240, the second term is a proportional term in the feedback control of the ignition timing for bringing the rotation speed Ne of the engine 22 closer to the idle rotation speed Nidl. "Kp2" is the gain of the proportional term. The third term is an integral term in the feedback control of the ignition timing for bringing the rotation speed Ne of the engine 22 closer to the idle rotation speed Nidl. "Ki2" is the gain of the integral term.

Tf* = previous Tf* + Kp2 (Nidl-Ne) + Ki2 ∫ (Nidl-Ne) dt ... (2)

Next, the second term of the formula (2) is stored as a proportional term Pon in a RAM (not shown), the third term is stored as an integral term Ion in a RAM (not shown) (step S250), the target ignition timing Tf* is sent to the engine ECU 24 (step S260), and the second ignition timing setting routine is terminated. In step S250, if the proportional term Pon and the integral term Ion have already been stored, the new proportional term Pon and integral term Ion are overwritten on the proportional term Pon and integral term Ion already stored. Therefore, the last set proportional term Pon and integral term Ion are stored in the RAM. The engine ECU 24, which has received the target ignition timing Tf* in step S260, controls the ignition plug 130 so that it ignites at the target ignition timing Tf* (so that the ignition timing becomes the target ignition timing Tf*). With this control, the engine 22 can be idled while suppressing deterioration of the combustion of the engine 22.

Next, the operation when control is transferred between idle on and idle off when a catalyst warm-up request is made will be described. FIG. 5 is a flowchart showing an example of a transition ignition timing setting routine executed by the HVECU 70. The transition ignition timing setting routine is executed by the CPU of the HVECU 70 when a catalyst warm-up request is made and the control is transitioned from idle off to idle on, or from idle on to idle off.

When the transition ignition timing setting routine is executed, the CPU of the HVECU 70 executes a process to determine whether or not the transition is from idle on to idle off (step S300). When the transition is not from idle on to idle off, i.e., when the transition is from idle off to idle on, the proportional term Poff and integral term Ion stored in a RAM (not shown) are input (step S310). The proportional term Poff is the value last stored at idle off, that is, the proportional term Poff at idle off immediately before the idle on state. The integral term Ion is the integral term Ion last stored in the RMA at the previous idle on state.

When the proportional term Poff and integral term Ion are input in this manner, the target ignition timing Tf* is set using the input proportional term Poff and integral term Ion, the target ignition timing Tf* (previous Tf*) set immediately before executing this routine, and the following equation (3) (step S320), the target ignition timing Tf* is transmitted to the engine ECU 24 (step S350), and the transition ignition timing setting routine is terminated. The engine ECU 24, which has received the target ignition timing Tf* in step S350, controls the ignition plug 130 so that it ignites at the target ignition timing Tf* (so that the ignition timing becomes the target ignition timing Tf*). Therefore, when the idle-off state changes to the idle-on state, the ignition timing of the engine 22 is controlled using the integral term Ion stored at the end of the previous idle-on state.

Tf* = previous Tf* + Poff + Ion ... (3)

When transitioning from idle on to idle off in step S300, the proportional term Pon and integral term Ioff stored in a RAM (not shown) are input (step S330). The proportional term Pon is the value last stored at idle on, i.e., the proportional term Pon at idle on immediately before the idle off state. The integral term Ioff is the integral term Ioff last stored at the previous idle off state.

When the proportional term Pon and integral term Ioff are input in this way, the target ignition timing Tf* is set using the input proportional term Pon and integral term Ioff, the target ignition timing Tf* (previous Tf*) set immediately before executing this routine, and the following equation (4) (step S340), the target ignition timing Tf* is transmitted to the engine ECU 24 (step S350), and the transition ignition timing setting routine is terminated. The engine ECU 24, which has received the target ignition timing Tf* in step S350, controls the ignition plug 130 so that it ignites at the target ignition timing Tf* (so that the ignition timing becomes the target ignition timing Tf*). Therefore, when the idle-on state changes to the idle-off state, the ignition timing of the engine 22 is controlled using the integral term Ioff stored at the end of the previous idle-off state.

Tf* = previous Tf* + Pon + Ioff ... (4)

Figure 6 is an explanatory diagram for explaining an example of the time change in the idle state, the engine 22 rotation speed Ne, the motor torque Tm1, and the integral term Ion and integral term Ioff stored in the RAM. In the figure, the area surrounded by the dashed square is the period during which the combustion deterioration condition is met. The area surrounded by the dashed circle includes the integral terms Ion and Ioff stored in the RAM at the end of the idle on and idle off periods.

As shown in the figure, when there is a transition from idle off to idle on (time t2), the target ignition timing Tf* is set using the integral term Ion at the previous idle on time (the integral term immediately before time t1) rather than the integral term Ioff at the time of idle off immediately before the idle on state. When there is a transition from idle on to off (time t3), the target ignition timing Tf* is set using the integral term Ioff at the previous idle off time (the integral term immediately before time t2) rather than the integral term Ion at the time of idle on immediately before the idle off state. The reason for setting the target ignition timing Tf* in this manner is as follows.

In the first ignition timing setting routine of FIG. 3 and the second ignition timing setting routine of FIG. 4, when the combustion deterioration condition of the engine 22 is satisfied, the ignition timing of the engine 22 is feedback-controlled using an integral term calculated using different parameters when the engine is in the idle-off state and when the engine is in the idle-on state. Therefore, when the engine is in the idle-off state, or when the engine is in the idle-off state, the integral term of the feedback control changes suddenly, making it impossible to control the ignition timing appropriately, and the combustion state of the engine 22 may deteriorate. In the embodiment, when the engine is in the idle-off state, the integral term Ion at the time of the idle-on state before the idle-off state is stored, and when the engine is in the idle-on state after that, the integral term Ion at the time of the idle-on state stored is used to control the ignition timing of the engine 22. When the engine is in the idle-off state after that, the integral term Ioff at the time of the idle-off state stored is stored, and when the engine is in the idle-off state after that, the integral term Ioff at the time of the idle-off ... This makes it possible to suppress a sudden change in the integral term when transitioning from idle on to idle off or from idle on to idle off, and to suppress deterioration of combustion in the engine 22 when transitioning from idle on to idle off or from idle off to idle on.

According to the hybrid vehicle 20 of the embodiment described above, when a catalyst warm-up request is made, when the engine 22 is in the idle-off state and the engine 22 combustion deterioration condition based on the motor torque Tm is satisfied, the ignition timing of the engine 22 is feedback-controlled using the integral term Ioff calculated using the motor torque Tm, and when the engine 22 is in the idle-on state and the engine 22 combustion deterioration condition based on the engine 22 rotation speed Ne is satisfied, the ignition timing of the engine 22 is feedback-controlled using the integral term Ion calculated using the engine 22 rotation speed, and when the engine 22 transitions from idle-on to idle-off, the integral term Ion at the time of idle-on before the transition to idle-off is stored, and when the engine 22 subsequently becomes idle-on, the ignition timing of the engine 22 is controlled using the integral term Ion at the time of idle-on that has been stored, and when the engine 22 transitions from idle-off to idle-on, the integral term Ioff at the time of idle-off before the transition to idle-on is stored, and when the engine 22 subsequently becomes idle-off, the ignition timing of the engine 22 is controlled using the integral term Ioff at the time of idle-off that has been stored, thereby suppressing deterioration of the engine 22 combustion.

In the hybrid vehicle 20 of the embodiment, the target ignition timing Tf* is set using a proportional term and an integral term in step S150 of the first ignition timing setting routine in FIG. 3 and step S240 of the second ignition timing setting routine in FIG. 4. However, the target ignition timing Tf* may be set using only the integral term without using the proportional term.

In the embodiment, the present invention is applied to a hybrid vehicle 20 equipped with an engine 22, a planetary gear 30, and motors MG1 and MG2. However, the present invention may also be applied to a so-called one-motor hybrid vehicle equipped with an engine and one motor. Furthermore, the present invention may also be applied to hybrid vehicles other than automobiles, such as trains and construction vehicles.

The following describes the relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem. In the embodiment, the engine 22 corresponds to the "engine", the motor MG1 corresponds to the "motor", and the engine ECU 24, motor ECU 40, and HVECU 70 correspond to the "control device".

The correspondence between the main elements of the Examples and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the Examples are examples for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Means for Solving the Problem column.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the invention.

The present invention can be used in the hybrid vehicle manufacturing industry, etc.

20 Hybrid vehicle, 22 Engine, 24 Engine ECU, 26 Crankshaft, 28 Damper, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheels, 40 Motor ECU, 41, 42 Inverter, 41a, 41b, 51b Current sensor, 43, 44 Rotational position sensor, 50 Battery, 51a Voltage sensor, 51c Temperature sensor, 52 Battery ECU, 54 Power line, 70 HV ECU, 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 pipe, 124 Throttle valve, 124a Throttle valve position sensor, 124b Throttle motor, 125 surge tank, 126 fuel injection valve, 128 intake valve, 129 combustion chamber, 130 spark plug, 132 piston, 133 exhaust valve, 134 exhaust pipe, 136 purification device, 136a purification catalyst, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, 148 air flow meter, 149 temperature sensor, 150 pressure sensor, 152 upstream air-fuel ratio sensor, 154 downstream air-fuel ratio sensor, MG1, MG2 motor.

Claims (1)

an engine equipped with a purification device having a purification catalyst;
a motor capable of inputting and outputting power to and from an output shaft of the engine;
a control device which, when a catalyst warm-up request for warming up the purification catalyst is made, controls the engine so that the ignition timing of the engine becomes a first ignition timing for promoting warm-up of the engine while feedback-controlling the engine speed by the motor during idle-off when the engine is operated under load, and controls the engine so that the ignition timing of the engine becomes a second ignition timing different from the first ignition timing and the engine speed becomes an idle speed while controlling the motor with a torque command of a value of 0 during idle-on when the engine is operated under idle;
A hybrid vehicle comprising:
The control device includes:
When the catalyst warm-up request is made,
feedback control an ignition timing of the engine using an integral term calculated using the torque of the motor when the engine is in the idle-off state and a combustion deterioration condition of the engine based on the torque of the motor is established;
feedback control an ignition timing of the engine using the integral term calculated using the engine speed when the engine is in the idle-on state and the combustion deterioration condition based on the engine speed is satisfied;
When transitioning from the idle-on state to the idle-off state, the integral term at the time of the idle-on state before transitioning to the idle-off state is stored, and when the idle-on state is subsequently reached, the ignition timing of the engine is controlled using the integral term at the time of the idle-on state that has been stored;
When the idle-off state is changed to the idle-on state, the integral term at the time of the idle-off state before the idle-on state is changed is stored, and when the idle-off state is subsequently changed, the ignition timing of the engine is controlled using the integral term at the time of the idle-off state that has been stored.
Hybrid car.

Images