JP2017095098A - Vehicular drive apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus capable of correcting an initial voltage determination that is erred particularly in association with polarization in the case of improving drivability by extending the usage range of a motor-generator to a torque assist during a vehicular travel.SOLUTION: A vehicular drive apparatus including means (51) for connecting disconnect-connect means (43) when no torque assist is executed, and executing a torque assist with the disconnect-connect means (43) disconnected when the torque assist is started, further includes: means (51) for executing an engine auto-stop with the disconnect-connect means (43) disconnected when an idling-stop permissible condition is established; means (51) for automatically restarting the engine when an idling-stop release condition is established during the engine auto-stop; and means (51) for inhibiting a torque assist when determining that a voltage is reduced in either of batteries (41, 42) during the engine auto-stop or when determining that a discharge current from either of the batteries (41, 42) is excessive.SELECTED DRAWING: Figure 5

Description

The present invention relates to a vehicle drive device, and more particularly to a torque assist vehicle using two batteries.

Since the starter is used every time the engine is restarted in the vehicle that performs idle stop, the power consumption of the battery increases compared to the vehicle that does not perform idle stop. As a countermeasure, there is one provided with a plurality of batteries of a first battery and a second battery (see Patent Document 1).

JP 2008-082275 A

By the way, the technique of Patent Document 1 considers only idle stop control. There is no description regarding the distribution of the electric load to the two batteries when the use range of the motor generator is expanded to torque assist during vehicle travel.

Therefore, the present invention has an object to provide an apparatus capable of correcting an erroneous initial voltage determination particularly associated with polarization when the range of use of a motor generator is extended to torque assist during vehicle running to improve drivability. To do.

A first battery used as a power source for torque assist during torque assist; a second battery used as a power source for an electric load other than torque assist during torque assist; and connection / disconnection means for connecting / disconnecting the first battery and the second battery; And connecting / disconnecting means when not performing torque assist, and providing torque assist execution means for executing the torque assist after disconnecting the connection / disconnection means when starting the torque assist. In this case,
The vehicle drive device of the present invention further includes an engine automatic stop execution means for executing an automatic engine stop after disconnecting the connecting / disconnecting means when an idle stop permission condition is satisfied, and an idle stop release during the engine automatic stop. Engine automatic restart means for automatically restarting the engine when the condition is satisfied, and when it is determined that there is a voltage drop in any of the batteries during the automatic engine stop, or a discharge current from any of the batteries Torque assist prohibiting means for prohibiting the torque assist when it is determined that the torque assist is excessive.

If the second battery is discharged during the automatic engine stop, the influence of polarization is eliminated.
Therefore, according to the present invention, when the initial voltage of the second battery is determined, if the voltage is determined to be higher due to the polarization and the torque assist is permitted, the voltage drop during the automatic engine stop eliminates the influence of the polarization. It will be. This makes it possible to correct erroneous determination due to polarization at the time of initial voltage determination without newly performing a diagnosis of whether or not polarization has occurred. In addition, according to the present invention, in the case where the torque assist emergency stop means that immediately stops the torque assist due to the voltage drop during the torque assist is provided, the torque shock due to the torque assist emergency stop can be prevented.

1 is a schematic configuration diagram of a vehicle drive device according to a first embodiment of the present invention. It is a control system figure of a gasoline engine. It is a timing chart from engine restart. It is a flowchart for demonstrating torque assist. It is a schematic block diagram of the power supply device used for the torque assist vehicle using two batteries. It is a model figure which shows changes, such as a sub battery voltage and a sub battery electric current, when driving | running | working a vehicle by switching an ignition switch from OFF to ON. It is a flowchart for demonstrating the initial voltage determination of idle stop permission about a subbattery. It is a characteristic view of the first determination threshold value 1 for idle stop. It is a flowchart for demonstrating the initial voltage determination of idle stop permission about a main battery. It is a characteristic view of the initial determination threshold value 2 for idle stop. It is a flowchart for demonstrating the initial voltage determination of torque assistance permission about a subbattery. It is a characteristic view of the initial determination threshold value 1 for torque assist. It is a flowchart for demonstrating the initial voltage determination of torque assistance permission about a main battery. It is a characteristic view of the initial determination threshold value 2 for torque assist. It is a flowchart for demonstrating the setting of an id stop permission flag. FIG. 6 is a model diagram showing changes in a torque assist permission flag, a torque assist execution flag, an assist torque, a torque assist emergency stop flag, and a main battery voltage during torque assist. It is a flowchart for demonstrating the emergency stop of torque assistance. It is a flowchart for demonstrating the voltage determination in idling stop of torque assistance permission. It is a characteristic view of the determination threshold value 1 during idle stop. It is a characteristic view of the determination threshold value 2 during idle stop. It is a model figure which shows the change of an ignition switch, a starter switch, an engine speed, relay 43 temperature, a sub battery voltage, a cold machine determination flag, and an idle stop permission flag.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a drive device for a vehicle 1 according to a first embodiment of the present invention. In FIG. 1, a vehicle 1 includes an engine 2, a motor generator 21, and an air conditioner compressor 31. In other words, the output shaft 3 of the engine 2, the rotation shaft 22 of the motor generator 21, and the rotation shaft 32 of the air conditioner compressor 31 are arranged in parallel, the crank pulley 3 at one end of the output shaft 3, and the pulleys on the rotation shafts 22 and 32. 23 and 33 are attached. A belt 5 is wound around each of the three pulleys 3, 23, 33, and the output shaft 3, the rotating shafts 23, 3,
3, power is transmitted (conducted) by the belt 5.

The engine 2 is also provided with a starter 6 used for starting the engine. A torque converter 8 and a belt type automatic transmission 9 are connected to the other end of the output shaft 3 of the engine 2. The torque converter 8 has a pump impeller and a turbine runner (not shown). The belt-type automatic transmission 9 includes a primary pulley and a secondary pulley (not shown) and a steel belt that is wound around these pulleys. The rotational driving force of the engine 2 is finally transmitted to vehicle driving wheels (not shown) via the torque converter 8 and the automatic transmission 9.

As a power source for the vehicle 1, a main battery 41 and a sub battery 42 are provided. Both are 14
V battery. The two batteries 41 and 42 are connected by two relays 43 arranged in parallel.

The starter 6 and the motor generator 21 are connected between the main battery 41 and the relay 43, and power is supplied from the main battery 41. Motor generator 21
Is composed of an AC machine, and therefore includes an inverter 24 for converting DC from the main battery 41 into AC.

An engine control module 51 is provided to control the engine 2, starter 6 and motor generator 21.

Here, the configuration of the gasoline engine will be outlined with reference to FIG. 2. FIG. 2 is a control system diagram of the gasoline engine. Each intake port (not shown) is provided with a fuel injection valve 7. The fuel injection valve 7 supplies fuel to the engine 2 intermittently.

The intake passage 11 is provided with an electronically controlled throttle valve 12, and the throttle motor 13 controls the opening of the throttle valve 12 (hereinafter referred to as “throttle opening”). The actual throttle opening is detected by the throttle sensor 14 and input to the engine control module 51.

The engine control module 51 has an accelerator opening (from the accelerator sensor 53 (
The amount of depression of the accelerator pedal 52), the crank angle signal from the crank angle sensor 54,
An intake air amount signal from the air flow meter 55 is input. Crank angle sensor 54
From this signal, the rotational speed of the engine 2 is calculated. Engine control module 51
Then, based on these signals, the target intake air amount and the target fuel injection amount are calculated, and a command is issued to the throttle motor 13 and each fuel injection valve 7 so as to obtain the target intake air amount and the target fuel injection amount.

Here, the control of the intake air amount will be outlined (refer to Japanese Patent Laid-Open No. 9-287513).
A target basic intake air amount and a target equivalent ratio tDML are calculated by searching a predetermined map from the accelerator opening APO and the engine speed Ne. A value obtained by dividing the target basic intake air amount by the target equivalent ratio tDML is set as the target intake air amount. Then, the target throttle valve opening is obtained by searching a predetermined map from the target intake air amount and the engine speed. The target throttle valve opening is converted into a command value and output to the throttle motor 13.

Next, control of fuel injection (fuel injection amount and fuel injection timing) will be outlined. The output of the air flow meter 55 is A / D converted and linearized to calculate the intake air amount Qa. From this intake air amount Qa and the engine speed Ne, the basic injection pulse width Tp0 [ms] that provides an air-fuel mixture with a substantially stoichiometric air-fuel ratio (equivalent ratio = 1.0) is expressed as Tp0 = K × Qa / Ne (where K is determined as a constant). next,
Tp = Tp0 × Fload + Tp−1 × (1−Fload)
Where Fload: weighted average coefficient,
Tp-1: Previous Tp,
The cylinder air amount equivalent pulse width Tp [ms] is obtained by the following equation. This is because the air amount flowing into the cylinder (combustion chamber) (that is, the cylinder air amount) has a response delay with respect to the intake air amount in the air flow meter section, and this response delay is approximated by a primary delay. The weighted average coefficient Fload [nameless number] which is a coefficient of the first order lag is obtained by searching a predetermined map from the product Ne · V of the rotational speed Ne and the cylinder volume V and the total flow path area Aa of the intake pipe. Based on the cylinder air amount equivalent pulse width Tp thus determined, the fuel injection pulse width Ti [ms] given to the fuel injection valve 7 is
Ti = Tp × tDML × (α + αm−1) × 2 + Ts
However, tDML: target equivalent ratio [anonymous number],
α: Air-fuel ratio feedback correction coefficient [anonymous number]
αm: Air-fuel ratio learning value [anonymous number]
Ts: Invalid injection pulse width [anonymous number],
It is calculated by the following formula. When the predetermined fuel injection timing comes, the fuel injection valve 7 is opened during this fuel injection pulse width Ti.

The gasoline engine 2 includes a spark plug facing the combustion chamber (cylinder). In the engine control module 51, a spark is generated in the spark plug by cutting off the primary current of the ignition coil at a predetermined time before the compression top dead center, thereby igniting the air-fuel mixture in the combustion chamber.

Further, when the engine control module 51 determines that there is an initial start request based on a signal from the starter switch 56, the starter 6 is driven to start the engine 2.

The engine control module 51 performs idle stop control for the purpose of improving fuel consumption. That is, the accelerator pedal 52 is not depressed (APO = 0),
The idle stop permission condition is satisfied when the brake pedal 57 is depressed (the brake switch 58 is ON) and the vehicle 1 is in a stopped state (vehicle speed VSP = 0). At this time, the fuel injection from the fuel injection valve 7 to the intake port is shut off and the engine 2 is stopped. This reduces wasteful fuel consumption.

Thereafter, when the accelerator pedal 52 is depressed in the idle stop state or the brake pedal 57 is returned (the brake switch 58 is OFF), the idle stop permission condition is not satisfied. At this time, the engine 2 is cranked using the motor generator 21 as a starter, the fuel injection from the fuel injection valve 7 and the spark ignition by the spark plug are restarted, and the engine 2 is restarted.

In this way, by using the motor generator 21 exclusively for engine restart from idle stop, the starter 6 is protected by reducing the frequency of use of the starter 6. When the starter 6 and the motor generator 21 are driven, the engine control module 51 cuts off both the two relays 43 so that the main battery 41 and the sub-battery 4
2 is electrically disconnected. This prevents the voltage of the sub-battery 42 from fluctuating with the start operation of the engine 2.

Returning to FIG. 1, the vehicle 1 includes an automatic transmission control unit 61. The automatic transmission control unit 61 controls the gear ratio of the automatic transmission 9 steplessly in accordance with the vehicle running conditions determined from the vehicle speed and the throttle opening. The torque converter 8 having a pump impeller and a turbine runner is provided with a mechanical lockup clutch for fastening and releasing the pump impeller and the turbine runner. The travel range of the vehicle that engages the lock-up clutch is predetermined as a lock-up region (vehicle speed and throttle opening are used as parameters). In the automatic transmission control unit 61, when the vehicle driving condition is in the lockup region, the lockup clutch is engaged to directly connect the engine 2 and the transmission 9, and the vehicle driving condition is not in the lockup region. Sometimes the lock-up clutch is released. When the engine 2 and the transmission 9 are in a directly connected state, the torque converter 8 does not absorb the torque, and the fuel efficiency is improved accordingly.

Vehicle 1 also has vehicle dynamics control (Vehicle Dynamics Contro
l) Unit 62, vehicle-sensitive electric power steering (Electric Power Steerin)
g) A control unit 63, an air conditioner auto amplifier 64, and a combination meter 66 are provided. The vehicle dynamic control unit 62 detects a skid state when the vehicle is likely to cause a side slip or a tail swing, and improves vehicle stability during traveling by brake control and engine output control. The vehicle speed sensitive electric power steering control unit 63 outputs an optimum assist torque signal to the EPS motor from the steering torque from the torque sensor and the vehicle speed.

The automatic transmission control unit 61, the vehicle dynamic control unit 62, the vehicle speed sensitive power steering control unit 63, and the combination meter 66 are electric loads that cannot tolerate a voltage drop. Therefore, these are supplied with power from the sub-battery 42.

Between the engine control module 51 and the three control units 61 to 63, the air conditioner auto amplifier 64, and the combination meter 66, a CAN (Controller
Area Network).

The present inventor has conceived that drivability is improved if the range in which the motor generator 21 is used can be expanded not only for starting the engine but also for torque assist during vehicle travel.

Here, there is a conventional apparatus in which a motor generator is mechanically coupled to an output shaft of an engine via a belt and a pulley, and the engine is started by the motor generator. However, the conventional apparatus considers only the case where the motor generator is used for starting the engine. There is no description of the design / control method of the motor generator when it is expanded to torque assist during vehicle travel.

Therefore, in the first embodiment of the present invention, the range of use of the motor generator 21 used for restart from idle stop is expanded to torque assist during vehicle travel. That is, torque assist using the motor generator 21 is permitted only when the engine rotational speed is in a predetermined rotational speed range after the engine 2 restarts from the idle stop and after the vehicle 1 starts running. Torque assist is prohibited when the engine rotational speed deviates from a predetermined rotational speed range while permitting torque assist.

When permitting torque assist, the engine 2 is torque-assisted.
A predetermined assist torque is generated in the motor generator 21 using the main battery 41 as a power source, and no assist torque is generated when torque assist is prohibited. As a result, good acceleration response (driability) can be obtained after the engine 2 is restarted and the vehicle 1 starts running.

The voltage of the main battery 41 is monitored and input to the engine control module 51. The engine control module 51 calculates the SOC (State Of Charge) of the main battery 41 based on the current of the main battery 41 and manages the charge / discharge balance of the main battery 41 based on this SOC.

The inverter 24 and the engine control module 51 are connected to a LIN (Local Input).
connect Network). Through this LIN, the engine control module 51 instructs the inverter 24 whether to drive the motor generator 21 or to generate electric power by the motor generator 21 or how much current to flow to drive the motor.

The rotation of the engine 2 is accelerated through the crank pulley 4, the pulley 23 and the belt 5 and transmitted to the motor generator 21. In the first embodiment, the speed increasing ratio through the two pulleys 4 and 23 and the belt 5 is 2.6, and when the rotational speed of the engine 2 is 5000 rpm, the rotational speed of the motor generator is 13000 rpm. The speed increasing ratio is not limited to 2.6.

The engine 2 and the motor generator 21 have resonance points of rotational vibration. The resonance point of this rotational vibration exists in the rotational speed range lower than 1000 rpm at the rotational speed of the engine 2. When torque assist is executed in a state where the tension of the belt 5 is low, belt slip occurs due to resonance of rotational vibrations of the engine 2 and the motor generator 21 (in the resonance rotational speed region), and the belt 5
There is a risk of squealing.

On the other hand, if the tension of the belt 5 is increased in order to prevent the belt from slipping due to the resonance, the friction between the crank pulley 4 and the belt 5 increases, resulting in deterioration of fuel consumption. Deterioration of fuel consumption due to increased friction between the crank pulley 4 and the belt 5 must be avoided, and the belt tension cannot be set high.

Therefore, considering the prevention of belt slip due to resonance, the rotational speed of the engine 2 is 1000 rp.
Torque assist is permitted in a rotational speed range higher than m (first threshold) (medium / high rotational speed range where the motor generator rotational speed is higher than 2600 rpm), and the engine rotational speed is 1000 rp.
Torque assist is prohibited in a rotation speed range of m (first threshold value) or less (a low rotation speed range of motor generator rotation speed of 2600 rpm or less).

The torque assist that is performed using the motor generator 21 when the engine speed exceeds the first threshold after the engine 2 is restarted and after the vehicle 1 starts running will be further described with reference to FIG. FIG. 3 is a timing chart showing how the engine speed, vehicle torque, vehicle speed, and accelerator opening change from the start of engine restart.
Here, the “vehicle torque” is a torque used for driving the vehicle, and the engine torque is usually the vehicle torque. On the other hand, when there is torque assist by the motor generator 21, the sum of the assist torque and the engine torque is the vehicle torque. The two flags shown at the bottom of FIG. 3 will be described later.

At t1, the idle stop permission condition is not satisfied, and the motor generator 2
1 is used to crank the engine 2 and restart the fuel injection from the fuel injection valve 7 and the spark ignition by the spark plug. As a result, if the engine 2 starts to burn, the engine speed rapidly increases, but at the timing t2 that crosses the predetermined complete explosion speed, the engine 2
Is determined to have restarted.

On the other hand, the driver (driver) depresses the accelerator pedal 52 a little near t2,
The fuel injection amount (Tp) from the fuel injection valve 7 and the air intake air amount Qa increase. by this,
Since the engine speed increases and the vehicle torque (= engine torque) increases, the vehicle 1
The vehicle started running at the timing of 3, and the vehicle speed increased slowly. Since the accelerator opening is constant even after the vehicle 1 is started, the engine rotation speed and the vehicle torque settle to constant values after the timing t3.

Next, if the driver depresses the accelerator pedal 52 at the timing t5, the engine speed increases as the accelerator opening increases. At time t6 when the engine speed RPM exceeds the first threshold value A, it is determined that the motor generator 21 has deviated from the low speed range, and current is supplied from the main battery 41 to the inverter 24 to drive the motor generator 21 as a motor. As a result, the motor torque is added to the engine torque in the middle / high rotation speed range of the motor generator 21 that is out of the low rotation speed range of the motor generator 21 (
(Torque assist), the acceleration desired by the driver can be obtained immediately. In this case, the torque generated by the motor generator 21 is gradually increased from zero to the maximum torque (see the second stage in FIG. 3).

On the other hand, if an attempt is made to cover the torque assist generated by the motor generator 21 with the torque generated by the engine 2, the fuel supply from the fuel injection valve 7 must be corrected in an increased amount, so that fuel consumption increases and fuel consumption deteriorates. On the other hand, when the vehicle 1 is decelerated, the motor generator 21 collects kinetic energy as electric energy and stores the collected electric energy in the main battery 41. If the engine generator 21 generates assist torque by using the main battery 41 that stores the electric energy as a power source when the engine rotational speed RPM exceeds the first threshold value A, fuel is not consumed. So there is no deterioration in fuel consumption. Further, the motor generator 21 can generate torque with better response than the engine 2. If the response is good, it can be avoided that the driver depresses the accelerator pedal too much.

The torque assist using the motor generator 21 performed by the engine control module 51 will be described in detail with reference to the flowchart of FIG. The flow in FIG. 4 is executed at regular intervals.

In step 1, it is determined whether or not the engine 2 has been started for the first time. The initial start of the engine 2 uses the starter 6. If it is not after the engine 2 is started for the first time, the current process is terminated.

It is determined whether or not the engine 2 has been restarted when the engine 2 has been started for the first time. The restart of the engine 2 is an engine start from an idle stop. Since the engine start from the idle stop is performed by the motor generator 21, it may be determined that the engine start from the idle stop is performed when the motor generator 21 is operated while the vehicle is stopped. If the engine is not started from the idle stop, the current process is terminated.

If the engine has been started from the idle stop, the process proceeds to step 3 where the vehicle 1
See if you are driving. When the vehicle speed is zero or less than a value close to zero, it is determined that the vehicle is stopped (not running) and the current process is terminated.

When the vehicle speed is not zero or exceeds a value close to zero, it is determined that the vehicle is traveling and the routine proceeds to step 4 to check whether the torque assist permission condition is satisfied. That is, it is determined that the torque assist permission condition is satisfied when all of the following conditions <1> and <2> are not satisfied. In other words, when any of the following conditions <1> and <2> is satisfied, it is determined that the torque assist permission condition is not satisfied, and torque assist is prohibited.
<1> When the lockup clutch is released
<2> When the SOC of the main battery 41 is less than the torque assist permission value,
Torque assist is prohibited in the above <1> because even if the assist torque is applied to the engine 2 when the lockup clutch is released, a part of the assist torque is absorbed by the torque converter 8, This is because the efficiency of torque transmission is poor. On the other hand, if the assist torque is applied to the engine 2 when the lockup clutch is engaged and the engine 2 and the transmission 9 are in the direct connection state, the assist torque is increased by the amount of the vehicle torque. The efficiency will not deteriorate.

Torque assist is prohibited when <2> above, in other words, S of the main battery 41
Torque assist is permitted when OC is equal to or greater than the torque assist permission value.

Thus, in this embodiment, the conditions for permitting torque assist are limited from the viewpoint of mainly preventing interference with the vehicle behavior control device.

When neither <1> nor <2> is satisfied, it is determined that the torque assist permission condition is satisfied, and the routine proceeds to step 5 where the torque assist permission flag = 1 is set. As shown in FIG. 3, the torque assist permission flag is switched from zero to 1 at the timing of t4.

On the other hand, when either <1> or <2> is satisfied, it is determined that the torque assist permission condition is not satisfied, and the process proceeds to step 6 to set the torque assist permission flag = 0.

In step 7, the torque assist permission flag is again checked. Torque assist permission flag =
When it is 1, the routine proceeds to step 8 where the engine speed RPM [rpm] and the first threshold A [r
pm]. The first threshold A is a value that determines the upper limit of the low rotation speed range of the motor generator 21 and is determined in advance. When engine rotation speed RPM exceeds the first threshold value, it is determined that motor generator 21 is out of the low rotation speed region. At this time, in order to execute the torque assist, the process proceeds from step 8 to step 9 to set the torque assist execution flag = 1.

With this torque assist execution flag = 1, the engine control module 51 sends current to the inverter 24 to drive the motor generator 21 as a motor. As shown in FIG. 3, the torque assist execution flag is switched from zero to 1 at the timing of t6, and t6
The motor torque is added to the engine torque with good response.

Here, when the motor generator 21 is driven as a motor, it is conceivable that the maximum current flows through the inverter 24 so that the motor generator 21 generates the maximum torque. However, if the motor generator 21 generates the maximum torque stepwise in the low rotation speed range of the engine 2 where it is easy to feel a driving shock, a driving shock occurs.
Therefore, the value of the current flowing through the inverter 24 is controlled so that the torque generated by the motor generator 21 gradually increases from zero to the maximum torque. Also, when releasing the motor torque, the value of the current flowing through the inverter 24 is controlled so as to gradually decrease from the maximum torque to zero.

A period during which torque assist is performed (that is, a period in which current is passed through the inverter 24) is set to a certain time. Since the power consumption of the main battery 41 is accelerated as long as the period for performing the torque assist is lengthened, this time is determined by adaptation so that the power consumption of the main battery 41 is not greatly affected.

On the other hand, when the engine rotational speed RPM is equal to or lower than the first threshold value A in step 8, it is determined that the motor generator 21 is in the low rotational speed range, and the routine proceeds to step 10 where the torque assist execution flag = 0 is set. With this torque assist execution flag = 0, the engine control module 51 cuts off the current supply to the inverter 24 and puts the motor generator 21 in a non-driven state. That is, if the engine speed RPM is less than or equal to the first threshold A by returning the accelerator pedal 52 on the assumption that the driver has obtained the desired acceleration by acceleration while the vehicle is running, the torque assist execution flag = 0 and the motor generator Torque assist by 21 is prohibited. Torque assist is executed when the motor generator 21 is out of the low rotational speed range after the vehicle starts running, and torque assist is prohibited when the motor generator 21 returns to the low rotational speed range during torque assist. As a result, the squealing of the belt 5 in the low rotational speed range of the motor generator 21 is prevented, the strength of the rotary shafts 3, 22, 32 of the pulleys 4, 23, 33 is ensured, and the fuel efficiency is improved and the acceleration response is good. (Drivability) can be compatible. Even if the torque assist permission condition is not satisfied in step 7, the process proceeds to step 10 to set the torque assist execution flag = 0.

The present embodiment is a case where the motor generator 21 generates up to the maximum torque, but is not limited to this. For example, a constant torque less than the maximum torque may be generated.

  Here, the effect of this embodiment is demonstrated.

In the present embodiment, a motor generator 21 mechanically coupled to the output shaft 3 of the engine 2 via a belt and a pulley 5 and a motor that generates a predetermined assist torque so that the engine 2 is torque-assisted. Generator control means (51);
Torque assist by the control means (51) is permitted when the engine rotational speed exceeds a first threshold value that defines the upper limit of the low rotational speed range after the vehicle 1 starts to travel, and the engine rotational speed is Torque assist permission / prohibition means (51) for prohibiting torque assist by the control means (51) when it is equal to or less than the first threshold. According to the present embodiment, after the vehicle 1 starts traveling, the motor generator 21 respects the driver's intention to accelerate (acceleration request) in the middle / high rotational speed range of the motor generator 21 and permits torque assist by the motor generator 21. Since the torque assist is prohibited when the motor generator 21 is in the low rotational speed range (see steps 8 to 10 in FIG. 4), the accelerator pedal 52 is operated in the middle / high rotational speed range of the motor generator 21 after the vehicle starts running. Acceleration responsiveness improves when stepping on and accelerating. Further, since torque assist is prohibited in the low rotation speed range of the motor generator 21, the squealing of the belt 5 in the low rotation speed range of the motor generator 21 is prevented, and the rotation shafts 3, 22, 32 of the pulleys 4, 23, 33 are prevented. The strength of can be secured. As described above, the squealing of the belt 5 in the low rotation speed range of the motor generator 21 is prevented, and the strength of the rotary shafts 3, 22, 32 of the pulleys 4, 23, 33 is secured, and the motor generator after the vehicle travel is started. Acceleration response can be improved at 21 mid and high rotation speed ranges.

According to the present embodiment, the battery 41 is provided, and the kinetic energy at the time of deceleration of the vehicle is collected as electric energy by the motor generator 21 and stored in the collected electric energy battery 41 of the motor generator 21, and the motor generator 21 has a predetermined energy. When the assist torque is generated, the battery 41 is used as a power source, so there is no fuel consumption,
Therefore, fuel consumption is improved.

According to the present embodiment, the motor generator 21 mechanically coupled to the output shaft 3 of the engine 2 via the belt 5 and the pulley 23 and the motor generator 21 with a predetermined assist torque so as to assist the engine 2 with torque. Motor generator control means (5
1) and an idle stop that causes the engine 2 to be stopped when the idle stop permission condition is satisfied, and the motor generator 21 is used to restart the engine 2 when the idle stop permission condition is not satisfied while the engine is stopped. When the engine speed exceeds a first threshold value that defines the upper limit of the low speed range of the motor generator 21 after restarting the engine 2 by the motor generator 21 and after the vehicle 1 starts to travel. Control means (
51) torque assist permission / inhibition means (51) for permitting torque assist by the control means (51) when torque assist is permitted, and when the engine rotational speed becomes equal to or lower than the first threshold value during torque assist permission. Therefore, the squealing of the belt 5 in the low rotational speed range of the motor generator 21 is prevented, and the rotating shafts 3, 22, 32 of the pulleys 4, 23, 33 are prevented.
In addition to improving the acceleration response (drivability) in the middle / high rotation speed range of the motor generator 21 after the vehicle starts running, the motor generator 21 and the idle stop
If the vehicle already has the restarting means (51), it can be dealt with only by changing the specifications of the motor generator 21 and changing the simple software, so that it is possible to avoid a significant increase in cost.

According to this embodiment, the vehicle behavior control device (62, 63) for controlling the behavior of the vehicle is provided,
Since torque assist is not allowed when these devices (62, 63) are operating,
It is possible to avoid deterioration of controllability by the vehicle behavior control device (62, 63).

According to this embodiment, the torque converter 8 that is interposed between the output shaft 3 of the engine 2 and the belt-type automatic transmission 9 and has a pump impeller and a turbine runner, and connects and disconnects the pump impeller and the turbine runner. A mechanical lock-up clutch and a lock-up clutch control means (61) for connecting the lock-up clutch when a certain vehicle running condition is established, and the lock-up clutch control means (61) engages the lock-up clutch. Since torque assist is not permitted when not, it is possible to avoid a reduction in torque transmission efficiency. This is the end of the description of torque assist.

Now, in the vehicle 1 of this embodiment, since the motor generator 21 is used every time the engine 2 is restarted from the idle stop state, the power consumption of the battery increases as compared with a vehicle that does not perform the idle stop. As a countermeasure against this, as shown in FIG. 5, a plurality of batteries including a main battery 41 (first battery) and a sub battery 42 (second battery) are provided. Here, FIG. 5 is a schematic configuration diagram of a power supply device used in an assist torque vehicle using two batteries 41 and 42, and the same parts as those in FIG.

As shown in FIG. 5, the first electrical load 44 has electrical components such as a headlamp 71 and a wiper 72, and these are powered by the main battery 41. On the other hand, the sub-battery 42
The second electric load 45 having the power source can be divided into an electrical component 81 that easily flickers due to the influence of the supply voltage and a controller 91 that is vulnerable to an instantaneous voltage drop. The electric parts 81 include an electric power steering (EPS) 82, a vehicle dynamic control (VDC).
) 83, a navigation system (NAVI) 84, a combination meter 66, and the like. The controllers 91 include an automatic transmission control unit 61, a vehicle dynamic control unit 62, a vehicle speed sensitive power steering control unit 63, an air conditioner auto amplifier 64, and an air conditioner inverter 92.

Next, FIG. 6 shows how the sub-battery voltage Vsb, the sub-battery current Isb, etc. change when the vehicle 1 is operated by switching the ignition switch 71 (see FIG. 5) from OFF to ON at the timing t0. It is the model figure which showed whether.

FIG. 6 shows changes in the sub battery voltage and the sub battery current, and does not show changes in the main battery voltage and the main battery current. Each change in the main battery voltage and the main battery current is different from each change in the sub battery voltage and the sub battery current, particularly during the initial start. This is because the first start is performed using the main battery 41 after the relay 43 is disconnected at the first start. In the remaining portions except for the initial start, the main battery voltage and the main battery current change in the same manner as the sub battery voltage and the sub battery current.

FIG. 6 shows an example in which two engine automatic stops (hereinafter referred to as “idle stop”) and one torque assist are performed. That is, the driver uses the starter 6 to start the engine for the first time during the period from t2 to t3. Relay 4 from timing t4
The first idle stop (abbreviated as “IS” in the figure) is started after disconnecting 3 and the first idle stop is released because the idle stop release condition is satisfied at the timing t6. Torque assist (abbreviated as “TA” in the figure) is started after the relay 43 is disconnected at the timing of t7, and the torque assist is terminated at the timing of t8 when a certain time has elapsed from t7. The relay 43 is disconnected at the timing t9 and the second idle stop is started. Since the idle stop cancellation condition is satisfied at the timing t11, the second idle stop is canceled.

In the present embodiment, voltage determination as to whether or not to perform torque assist is performed immediately after the ignition switch 71 is turned on, and also during idle stop as follows. On the other hand, whether or not to permit idling stop is determined only immediately after the ignition switch 71 is turned on. Hereinafter, it demonstrates in this order.

[1] Torque Assist Permit Initial Voltage Determination for Sub-battery Is torque assist permitted at timing t1 when a predetermined time X [ms] has elapsed from timing t0 when ignition switch 71 is switched from OFF to ON in FIG. The first voltage judgment is made. Here, it is assumed that the initial voltage determination for permitting torque assist is OK. Therefore, even if the first idle stop at t4 to t6 is not performed, t
If the remaining torque assist permission conditions other than the battery voltage are satisfied at the timing of 7, torque assist is performed.

The initial voltage determination for permitting torque assist is performed by comparing the sub-battery voltage Vsb at t1 with the initial determination threshold value 1 for torque assist. Here, considering the sub-battery voltage at t0 (referred to as “initial battery voltage”) as a reference, the sub-battery voltage Vsb at t1 is a difference voltage from the initial battery voltage at a certain time X (t0 to t1). Represents. In other words, t
The sub-battery voltage Vsb at 1 represents a voltage drop rate (about a voltage drop). Therefore, the lower the sub-battery voltage Vsb at t1, the greater the voltage drop rate.

The determination value for determining whether or not the voltage drop rate is large is the torque determination initial determination threshold value 1. Therefore, when the sub-battery voltage Vsb at t1 is less than the torque assist initial determination threshold value 1, the sub-battery voltage drop rate is large (hereinafter, the sub-battery voltage drop rate is large. It is said that there is. t1
When the sub-battery voltage Vsb is equal to or higher than the torque assist initial determination threshold value 1, it is determined that the sub-battery voltage drop rate is not large, that is, the sub-battery 42 has no voltage drop.

The end of the fixed time X is a timing at which the battery voltage Vsb, which decreases from t0, settles to some extent. Specifically, it is determined by conformity.

The torque assist initial determination threshold value 1 is calculated from the sub battery current Isb at t1. The reason why the initial threshold value 1 for torque assist is made dependent on the sub battery current at t1 is that the voltage drop rate of the sub battery 42 differs depending on the sub battery current Isb at t1. The sub battery current Isb is detected by a current sensor 48 (see FIG. 5).

As shown in the uppermost part of FIG. 6, the torque assist initial determination threshold 1 (abbreviated as “TA initial determination threshold 1” in the figure) is an idle stop initial determination threshold (hereinafter “IS initial determination threshold in the figure). 1 ”and abbreviated as 1).

[2] Torque Assist Permit Initial Voltage Determination for Main Battery The main battery 41 is determined by comparing the main battery voltage Vmn at the determination timing during the initial start and the torque assist initial determination threshold 2. That is, when the main battery voltage Vmn at the determination timing during the initial start is less than the initial threshold value 2 for torque assist, it is determined that the main battery 41 has a voltage drop. When the main battery voltage Vmn at the determination timing during the initial start is equal to or greater than the torque determination initial determination threshold value 2, it is determined that there is no voltage drop in the main battery 41. The determination timing during the initial start is determined in advance.

The torque assist initial determination threshold value 2 is calculated from the main battery current Imn at the determination timing during the initial start. The reason why the initial threshold value for torque assist 2 is made dependent on the main battery current Imn at the determination timing during the initial start is that the voltage drop rate of the main battery 41 is different depending on the main battery current Imn at the determination timing during the initial start. It is to do. The main battery current Imn is detected by a current sensor 47 (see FIG. 5).
Also for the main battery 42, the initial threshold value for torque assist 2 is set higher than the initial threshold value for idle stop 2 described later.

[3] Torque Assist Permitted Voltage Determination During Idle Stop For the initial voltage determination of the torque assist permission, the sub battery 42 and the main battery 41
Since the judgment timings differed between [1] and [2] as described above. On the other hand, the voltage determination during idling stop for permitting torque assist is not described separately because the sub battery 42 and the main battery 41 have the same determination timing.

In FIG. 6, a predetermined time Y [m] from the timing t4 when the first idle stop is started.
At time t5 when s] elapses, a voltage determination is made as to whether or not torque assist is permitted.
Here, it is assumed that the voltage determination during idling stop for permitting torque assist is OK.
For this reason, torque assist is performed if the remaining torque assist permission conditions other than the battery voltage are satisfied at the timing of t7 after the completion of the first idle stop. Similarly, a predetermined time Y [ms] elapses from the timing t9 when the second idle stop is started.
At 10 timing, the torque assist permission voltage determination during idling stop is performed.

The torque assist permission voltage determination during idling stop is performed by comparing the sub-battery voltage Vsb and the idling stop determination threshold 1 at timings t5 and t10. here,
Sub-battery voltage at t5 and t10 (referred to as “idle stop start battery voltage”)
Is the reference, the sub-battery voltage Vsb at t5 and t10 is a constant time Y (t0 to t
The difference voltage from the idle stop start battery voltage in 1) is represented. In other words, t
5, the sub-battery voltage Vsb at t10 represents a voltage drop rate (voltage drop degree). Therefore, the lower the sub-battery voltage Vsb at t5 and t10, the greater the voltage drop rate.

A determination value for determining whether or not the voltage drop rate is large is the determination threshold value 1 during idling stop. For this reason, when the sub battery voltage Vsb at t5 and t10 is less than the determination threshold value 1 during idling stop, it is determined that the voltage drop rate of the sub battery 42 is large, that is, the sub battery 42 has a voltage drop. When the sub-battery voltage Vsb at t5 and t10 is equal to or higher than the constant threshold value 1 during idle stop, it is determined that the voltage drop rate of the sub-battery 42 is not large, that is, there is no voltage drop in the sub-battery 42.

Similarly, the main battery 41 is also compared by comparing the main battery voltage Vmn at t5 and t10 with the determination threshold value 2 during idling stop. That is, when the main battery voltage Vmn at t5 and t10 is less than the determination threshold value 2 during idle stop, it is determined that the main battery 41 has a large voltage drop rate, that is, the main battery 41 has a voltage drop. When the main battery voltage Vmn at t5 and t10 is equal to or higher than the determination threshold value 2 during idling stop, the voltage drop rate of the main battery 41 is not large, that is, the main battery 41
It is determined that there is no voltage drop.

The determination threshold value 1 during idle stop is calculated from the sub battery current Isb at t5 and t10. Similarly, the determination threshold value 2 during idle stop is calculated from the main battery current Imn at t5 and t10. The threshold values 1 and 2 for each idle stop are set to each battery current Is.
b and Imn depend on the battery currents Isb and Imn.
This is because the voltage drop ratios 1 and 42 are different.

As shown in FIG. 6, the determination threshold value 1 during idling stop is higher than the initial determination threshold value 1 for torque assist. Similarly, for the main battery 42, the determination threshold value 2 during idling stop is set higher than the initial determination threshold value 2 for torque assist.

The end of the predetermined time Y is a timing at which each battery voltage that drops from t4 and t9 settles to some extent. Specifically, it is determined by conformity.

[4] Initial voltage determination for idling stop permission for sub-battery In FIG. 6, is idling stop permitted at timing t1 when a predetermined time X [ms] elapses from timing t0 when ignition switch 71 is switched from OFF to ON? The first voltage judgment is made. Here, it is assumed that the initial voltage determination for the idle stop permission is OK. For this reason, if the remaining idle stop permission conditions other than the battery voltage are satisfied at the timing of t4, the first idle stop is performed. Similarly, if the remaining idle stop permission condition other than the battery voltage is satisfied at the timing of t9, the second idle stop is performed.

The initial voltage determination for permitting idle stop is the same as the initial voltage determination for permitting torque assist. That is, the comparison is made by comparing the sub-battery voltage Vsb at the timing t1 and the initial determination threshold value 1 for idle stop. When the sub battery voltage Vsb at t1 is less than the idling stop initial determination threshold value 1, it is determined that the voltage drop rate of the sub battery 42 is large, that is, the sub battery 42 has a voltage drop. When the sub battery voltage Vsb at t1 is equal to or higher than the initial determination threshold value 1 for idle stop, it is determined that the voltage decrease rate of the sub battery 42 is not large, that is, the sub battery 42 has no voltage decrease.

The above-mentioned idle stop initial determination threshold 1 is calculated from the sub-battery current Isb at t1.

[5] Initial Voltage Determination for Allowing Idle Stop for Main Battery The main battery 41 is determined by comparing the main battery voltage Vmn at the determination timing during the initial start and the initial determination threshold value 2 for idle stop. When the main battery voltage Vmn at the determination timing during the initial start is less than the initial determination threshold value 2 for idle stop, it is determined that the main battery 41 has a large voltage decrease rate, that is, the main battery 41 has a voltage decrease. When the main battery voltage Vmn at the determination timing during the initial start is equal to or greater than the initial determination threshold value 2 for idle stop, it is determined that the voltage decrease rate of the main battery 41 is not large, that is, the main battery 41 has no voltage decrease. In the case of [5], the determination timing during the initial start may be the same as the determination timing of [2] above.

The idling stop initial determination threshold 2 is calculated from the main battery current Imn at the determination timing during the initial start.

The above-mentioned [4] and [5] idle stop permission initial voltage determination, [1] and [2] torque assist permission initial voltage determination, and [3] torque assist permission idle stop voltage determination are performed. Further description will be given based on the following flowchart.

The flow of FIG. 7 is for performing the initial voltage determination of the idle stop permission for the sub battery 42. This flow is executed only once at a timing when a certain time X [ms] has elapsed from the switching timing of the ignition switch 71 from OFF to ON.

In FIG. 7, in step 1, it is determined whether or not it is a cold start. This is the water temperature sensor 7
2 (see FIG. 5) is compared with the actual cooling water temperature and the cold machine determination threshold value (see FIG. 21). If the actual cooling water temperature is less than the cold machine determination threshold value, What is necessary is just to judge that it is not in a cold state when is more than a cold machine determination threshold value. Whether or not it is at the start time may be determined based on the starter switch 56 (see FIG. 5).

When it is cold start, the process proceeds to step 2 to check whether or not the initial voltage is OK. This is because the sub-battery voltage Vsb [at a timing (t1 in FIG. 6) when a certain time X [ms] has elapsed from the switching timing of the ignition switch 71 from OFF to ON.
V] is compared with the initial determination threshold value 1 [V] for idle stop. When the sub-battery voltage Vsb after the elapse of X from the ignition switch ON is equal to or higher than the initial determination threshold value 1 for idle stop, it is determined that the initial voltage is OK, and the process proceeds to step 3 to set the idle stop initial OK determination flag = 1. . The idle stop first time OK determination flag = 1 means that there is no voltage drop in the sub battery 42.

On the other hand, when the sub battery voltage Vsb after the elapse of X from the ignition switch ON is less than the initial determination threshold value 1 for idling stop, it is determined that the initial voltage is NG, and Step 4
And the idling stop first time OK determination flag = 0. The idling stop first time OK determination flag = 0 means that there is a voltage drop in the sub battery 42.

The initial determination threshold value 1 for idling stop is the sub-battery current Isb [at the timing (t1 in FIG. 6) when a certain time X [ms] has elapsed from the ignition switch ON.
A] is obtained by searching a table having the contents shown in FIG.

In FIG. 7, when it is not at the time of cold start in step 1, the process proceeds to step 5, and it is determined whether or not the idling stop first time OK determination flag = 1 for the sub battery at the start of the previous operation (the sub battery 42 did not have a voltage drop). View. When the idling stop first time OK determination flag = 1 for the sub-battery at the start of the previous operation (the sub-battery 42 has no voltage drop), the process proceeds to step 2 and subsequent steps.

On the other hand, at the time of the previous operation start in step 5, the sub-battery idle stop first time O
When the K determination flag = 0 (the sub battery 42 has a voltage drop), step 6
Then, the idle stop permission flag is set to 0 (idle stop is prohibited).

The flow of FIG. 9 is for performing the initial voltage determination of the idle stop permission for the main battery 41. This flow is executed only once at the determination timing during the initial startup. Since the content of the process itself is the same as that for the sub-battery 42 shown in FIG. 7 except that the determination timing is different, the difference will be mainly described.

In step 11, it is determined whether or not it is a cold start. When it is cold start time, the routine proceeds to step 12 where it is checked whether or not the initial voltage is OK. This is because the main battery voltage Vmn [V] at the determination timing during the initial start and the initial determination threshold for idle stop 2 [V
] And comparison. When the main battery voltage Vmn at the determination timing during the initial start is equal to or greater than the initial determination threshold value 2 for idle stop, it is determined that the initial voltage is OK, and the process proceeds to step 13 to set the idle stop initial OK determination flag = 1. . The idle stop first time OK determination flag = 1 means that there is no voltage drop in the main battery 41.

On the other hand, when the main battery voltage Vmn at the determination timing during initial start is less than the initial determination threshold value 2 for idle stop, it is determined that the initial voltage is NG, and the routine proceeds to step 14 where the idle stop initial OK determination flag = 0. And The idling stop first time OK determination flag = 0 means that the main battery 41 has a voltage drop.

The above-mentioned initial determination threshold value 2 for idle stop is obtained by searching a table having the contents shown in FIG. 10 from the main battery current Imn [A] at the determination timing during the initial start.

In FIG. 9, when it is not at the time of cold machine start at step 11, it progresses to step 15, and it was idle stop first time OK determination flag = 1 about the main battery at the time of the previous driving | operation start (
Whether the main battery 41 has no voltage drop). At the start of the previous operation, the initial stop OK determination flag = 1 for the main battery (main battery 41
Step 12 and the subsequent steps are also performed.

On the other hand, when the idling stop first time OK determination flag = 0 for the main battery at the start of the previous operation in step 15 (the main battery 41 has a voltage drop), the process proceeds to step 16 and the idling stop permission flag = 0 (idle). Prohibit stop)
.

Next, the flow of FIG. 11 is for performing initial voltage determination of torque assist permission for the sub-battery 42. This flow is executed only once at a timing when a certain time X [ms] has elapsed from the switching timing of the ignition switch 71 from OFF to ON. The contents of the processing are the same as in the case shown in FIG.

In FIG. 11, in step 21, it is determined whether or not it is a cold start. When it is cold start time, the routine proceeds to step 22 to check whether or not the initial voltage determination is OK. This is because the sub-battery voltage Vsb [V] at a timing (t1 in FIG. 6) when a certain time X [ms] has elapsed from the switching timing of the ignition switch from OFF to ON and the torque assist initial determination threshold 1 [V]. ] And comparison. When the sub-battery voltage Vsb after the elapse of X from the ignition switch ON is equal to or greater than the torque assist initial determination threshold value 1, it is determined that the initial voltage is OK, and the process proceeds to step 23 where the torque assist initial OK determination flag = 1.
And The torque assist first time OK determination flag = 1 means that there is no voltage drop in the sub battery 42.

On the other hand, when the sub battery voltage Vsb after the elapse of X from the ignition switch ON is less than the torque assist initial determination threshold value 1, it is determined that the initial voltage is NG, and step 24 is performed.
The torque assist first time OK determination flag = 0 is set. The torque assist first time OK determination flag = 0 means that there is a voltage drop in the sub battery 42.

The initial threshold value 1 for torque assist is the sub battery current Isb [A at a timing (t1 in FIG. 6) when a certain time X [ms] has elapsed since the ignition switch was turned on.
] By searching a table having the contents shown in FIG.

In FIG. 11, when it is not cold start at step 21, the process proceeds to step 25, and it is determined whether or not the torque assist initial OK determination flag = 1 for the sub battery at the start of the previous operation (the sub battery 42 did not have a voltage drop). View. When the torque assist first time OK determination flag = 1 for the sub-battery at the start of the previous operation (the sub-battery 42 has no voltage drop), the process proceeds to step 22 and thereafter.

On the other hand, in step 25, the torque assist first time O for the sub battery at the start of the previous operation.
If the K determination flag = 0 (the sub battery 42 has a voltage drop), step 2
Proceed to step 6 and set the torque assist permission flag = 0 (torque assist is prohibited).

The flow of FIG. 13 is for performing the initial voltage determination of the torque assist permission for the main battery 41. This flow is executed only once at the determination timing during the initial startup. Since the content of the processing itself is the same as that shown in FIG. 11, the different parts will be mainly described.

In FIG. 13, in step 31, it is determined whether or not it is a cold start. When it is cold start time, the routine proceeds to step 32, where it is determined whether or not the initial voltage determination is OK. This is performed by comparing the main battery voltage Vmn [V] at the determination timing during the initial start and the torque assist initial determination threshold 2 [V]. That is, the initial voltage is OK when the main battery voltage Vmn at the determination timing during the initial start is equal to or greater than the initial threshold value 2 for torque assist.
The process proceeds to step 33 and sets the torque assist initial OK determination flag = 1.
The torque assist first time OK determination flag = 1 means that there is no voltage drop in the main battery 41.

On the other hand, when the main battery voltage Vmn at the determination timing during the initial start is less than the torque assist initial determination threshold 2, it is determined that the initial voltage is NG, and the routine proceeds to step 34 where the torque assist initial OK determination flag = 0. And Torque assist first time OK determination flag = 0
Means that the main battery 41 has a voltage drop.

The torque assist initial determination threshold value 2 is obtained by searching a table having the contents shown in FIG. 14 from the main battery current Imn [A] at the determination timing during the initial start.

In FIG. 13, when it is not at the time of cold start in step 31, the process proceeds to step 35, and the torque assist initial OK determination flag = 1 for the main battery at the start of the previous operation (
Whether the main battery 41 has no voltage drop). When the torque assist first time OK determination flag = 1 for the main battery at the start of the previous operation (the main battery 41 has no voltage drop), the process proceeds to step 32 and subsequent steps.

On the other hand, when the torque assist first time OK determination flag = 0 for the main battery at the start of the previous operation in step 35 (the main battery 41 has a voltage drop), the process proceeds to step 36 and the torque assist permission flag = 0 (torque) Assist is prohibited).

Each of the characteristics shown in FIGS. 8, 10, 12, and 14 only shows a tendency with respect to the current, and actually, the characteristics are determined by adaptation.

The flow in FIG. 15 is for setting the id stop permission flag, and is executed at regular intervals.

If all of the following conditions are satisfied in steps 41 to 46, the process proceeds to step 47, and the idle stop permission flag = 1 is set. If any one of the following conditions is not satisfied in steps 41 to 46, step Proceed to 48 to set the idle stop permission flag = 0.

<1> Step 41: The accelerator opening APO detected by the accelerator sensor 53 (see FIG. 5) is zero (the accelerator pedal is not depressed),
<2> Step 42: The vehicle speed VSP detected by the vehicle speed sensor 75 (see FIG. 5) is substantially zero (the vehicle is stopped),
<3> Step 43: The idle stop initial OK determination flag = 1 for the sub battery 42 (the sub battery 42 has no voltage drop),
<4> Step 44: Idle stop initial OK determination flag for main battery =
1 (the main battery 41 has no voltage drop),
<5> Step 45: The SOC (SOCsb) of the sub battery 42 is equal to or higher than the idle stop permission determination SOC of the sub battery 42;
<6> Step 46: The SOC (SOCmn) of the main battery 41 is equal to or greater than the 41 idle stop permission determination SOC of the main battery,
Here, the SOC (State Of Charge) of the sub-battery 42 is the current sensor 48 (FIG. 5).
Is calculated by the engine control module 51 on the basis of the current value detected in step (1). The SOC (State Of Charge) of the main battery 41 is a current sensor 47 (FIG. 5).
Is calculated by the engine control module 51 on the basis of the current value detected in step (1). The idle stop permission determination SOC of the sub battery 42 and the idle stop permission determination SOC of the main battery 41 are determined in advance.

Next, the torque assist emergency stop will be described with reference to the timing chart of FIG. FIG. 16 is a model diagram showing how the torque assist permission flag, the torque assist execution flag, the assist torque, the torque assist emergency stop flag, and the main battery voltage change during torque assist.

In FIG. 16, when the torque assist permission flag is switched from zero to 1 at t21 and the torque assist execution flag is switched from zero to 1 at the timing of t22, the assist torque gradually increases from t22, and reaches a constant value (100 %) Settle down. On the other hand, when the torque assist permission flag is returned from 1 to zero at the timing of t25, the assist torque gradually decreases from t25 and returns to zero (0%) at the timing of t27. The torque assist execution flag returns to zero at t27.

Thus, torque assist is performed according to the command of the torque assist execution flag.
This is a case where the main battery voltage changes as shown by a short broken line at the bottom of FIG. 16 (normal time). That is, at the normal time, the voltage of the main battery 41 that is the power source of the motor generator 21 is lower than the timing t22 by the driving of the motor generator 21, but does not decrease to the guaranteed voltage limit.

Here, when the main battery voltage applied to each device such as the headlamp 71 and the wiper 72 is lowered, the limit at which the operation of each device is guaranteed at a certain voltage is reached. In other words, when the main battery voltage is lowered beyond this limit, the operation of each device is not guaranteed. This limit voltage is the “guaranteed voltage limit” above.
It is.

When the main battery 41 deteriorates, the main battery voltage decreases with torque assist. For example, as shown by the solid line at the bottom of FIG. 16, the main battery 41 decreases beyond the guaranteed voltage limit in the period from t24 to t26. Sometimes. If the torque assist is performed until the voltage exceeds the guaranteed voltage limit due to a decrease in the main battery voltage accompanying the torque assist, the operation of each device such as the headlamp 71 and the wiper 72 is performed during the period from t24 to t26. It cannot be guaranteed.

This is dealt with by emergency stop of torque assist. That is, as indicated by the broken line in the third row of FIG. 16, the main battery voltage during torque assist is less than the guaranteed voltage limit.
By returning the assist torque stepwise to zero (0%) at the timing of 24, the emergency stop of the torque assist is performed. As a result of the emergency stop of the torque assist, the main battery voltage rises away from the guaranteed voltage limit from the timing t24 as shown by the long broken line at the bottom of FIG. As a result, even if the main battery 41 is deteriorated, the operation of each device is guaranteed.

The flow in FIG. 17 is for emergency stop of torque assist, and is executed at regular intervals.

In step 51, the torque assist execution flag is viewed. The torque assist execution flag is set, for example, according to the flow of FIG. When the torque assist execution flag = 1, it is determined that torque assist is being performed, and the routine proceeds to step 52 where the main battery voltage Vmn [V] during torque assist is compared with the guaranteed voltage limit [V]. The guaranteed voltage limit can be known from a device constituting the first electric load 44 using the main battery 41 as a power source, and is set in advance. When the main battery voltage Vmn during torque assist is equal to or higher than the guaranteed voltage limit, it is determined that the operation of each device constituting the first electric load 44 is guaranteed, and the current process is terminated.

On the other hand, when the main battery voltage Vmn during the torque assist becomes less than the guaranteed voltage limit, it is determined that the operation of each device constituting the first electric load 44 cannot be guaranteed. At this time, the routine proceeds to step 53, where the torque assist permission flag = 0, and at step 54, the torque assist emergency stop flag = 1. In the flow (not shown), the torque assist emergency stop flag = 1 is received and the current supply to the motor generator 21 is cut off.

FIG. 16 shows that the torque assist emergency stop flag is switched from zero to 1 at the timing t24 when the main battery voltage becomes lower than the guaranteed voltage limit during torque assist (see the long broken line in the fourth stage in FIG. 16). ). In response to this, the assist torque is stepwise returned to zero (0%) at the timing of t24 in order to cut off the current supply to the motor generator 21 (see the third long dashed line in FIG. 16). As a result, the motor generator 21 does not consume the power of the main battery 41, so that the main battery voltage recovers away from the guaranteed voltage limit from the timing t24 (see the long broken line at the bottom of FIG. 16).

The flow in FIG. 18 is for determining the voltage during idling stop for permitting torque assist. This flow is executed only once when a certain time Y [ms] has elapsed from the idle stop start timing.

In FIG. 18, in step 61, a predetermined time Y [
ms] has elapsed (t5, t10 in FIG. 6), the sub battery voltage Vsb.
[V] and the idling stop determination threshold value 1 [V] are compared. As described above, the sub-battery voltage Vsb after the lapse of Y from the start of the idle stop represents a voltage drop rate (about a voltage drop), and the lower the sub-battery voltage Vsb after the lapse of Y from the start of the idle stop, the greater the voltage drop rate. It becomes. Accordingly, when the sub battery voltage Vsb after the elapse of Y from the start of idle stop is less than the idle stop determination threshold value 1, it is determined that the voltage drop rate of the sub battery 42 is large, that is, the idle stop voltage is NG. 62, 63
Proceed to

In step 62, the idle stop permission flag = 0 (idle stop release), and in step 63, the torque assist permission flag = 0 (torque assist prohibited). Even if the torque assist permission flag = 0 and the torque assist initial OK determination flag = 1 in the initial voltage determination of torque assist permission, the current idle stop is canceled and the subsequent torque assist is prohibited.

The reason why the current idle stop is canceled and the subsequent torque assist is prohibited when the sub-battery voltage Vsb after the elapse of Y from the start of the idle stop is less than the determination threshold value 1 during idle stop is as follows. That is, the present inventor has newly found that polarization occurs in the sub-battery 42 when the engine is temporarily stopped before the warm-up of the engine is completed, and immediately after that, when the engine is started again to operate the engine again. Here, the “polarization” of the sub-battery 42 refers to a phenomenon in which the electrode potential of the sub-battery 42 shifts to a higher side from the static potential.
Due to the effect of this polarization generated in the sub-battery 42, it may be erroneously determined that the initial voltage for permitting torque assist is OK when determining the initial voltage for permitting torque assist. For example, if there is no polarization in the sub-battery 42, the sub-battery voltage is determined to be lower than the initial threshold value 1 for torque assist when determining the initial voltage for permitting torque assist, and the initial voltage for permitting torque assist is determined to be NG. And In this case, if the sub-battery voltage Vsb is detected to be apparently higher than the actual value due to the influence of polarization, it is erroneously determined that the initial voltage for permitting torque assist is OK because it is higher than the initial threshold value 1 for torque assist. It will end up.

The influence of the polarization generated in the sub-battery 42 will be described with further reference to FIG. FIG. 21 shows an ignition switch 71, a starter switch 56, an engine speed NE.
It is a model figure which shows each change of the relay 43, a cooling water temperature, a sub battery voltage, a cold machine determination flag, and an idle stop permission flag.

In FIG. 21, the cold start is performed at the timing t31, the engine is immediately stopped at the timing t33, and the cold start is performed at the timing t34 immediately thereafter. At this time, t
At the timing of 35, the initial voltage determination for permitting the idle stop and the initial voltage determination for permitting the torque assist are performed for the sub-battery 42. At this time, if there is no polarization in the sub-battery 42, the sub-battery voltage is less than the initial determination threshold value 1 for idle stop, and the idle stop permission flag = 0 as shown by the solid line in the eighth row of FIG. To do.
However, when polarization occurs in the sub-battery 42, the sub-battery voltage may become the idling stop initial determination threshold 1 or more due to the influence of polarization. As a result, the idle stop permission flag = 1 as shown by the broken line in the eighth row of FIG. 21 (
Falsely determined to be an idling stop). In this case, the initial voltage determination for torque assist permission is performed at the same timing as the initial voltage determination for idle stop permission. Therefore, even in the initial voltage determination for permitting torque assist for the sub-battery 42, the sub-battery 42
The torque assist permission flag is set to 1 due to the influence of the polarization generated in (1).

There are two methods for prohibiting the subsequent torque assist: a method of prohibiting only the torque assist immediately after, and a method of prohibiting all torque assist until the engine is subsequently stopped. Here, the reference timing for determining “after” is the timing after the elapse of Y from the start of the idle stop. “Immediate torque assist” refers to torque assist from t7 to t8 when subsequent torque assist is prohibited at timing t5 in FIG. 6, for example.

On the other hand, if many devices constituting the second electric load 45 that uses the sub-battery 42 as a power source are operating immediately before the start of the idle stop, the sub-battery 42 moves to the device constituting the second electric load 45 from the idle stop start timing. Start discharging. As described above, when the sub battery 42 is discharged from the start of the idle stop, when the predetermined time Y has elapsed from the start of the discharge, the rapid decrease in voltage due to the polarization of the sub battery 42 is eliminated. Has confirmed. ΔVsb1 represents the voltage drop after the lapse of Y from the start of the idle stop when the sub-battery 42 is not polarized, and ΔVsb1 represents the voltage drop after the lapse of the Y from the start of the idle stop when the sub-battery 42 is polarized. Let ΔVsb2. At this time, ΔvVsb2 when polarization is generated in the sub-battery 42 is larger than ΔVsb1 when polarization is not generated, but becomes the same voltage after the polarization is lost.
That is, if the time until the two sub-battery voltages match when the polarization has occurred due to the voltage drop from the start of discharge and when the polarization has not occurred is determined as Y, the polarization of the sub-battery 42 after Y has elapsed. The effect of is eliminated.

Therefore, at the timing when the sudden voltage drop due to the polarization of the sub-battery 42 is eliminated (
That is, after the elapse of Y from the start of idling stop, the sub-battery voltage Vsb and the idling stop determination threshold value 1 are compared again to make voltage determination without the influence of polarization. At this time, if the sub-battery voltage after the elapse of Y from the start of idle stop is less than the determination threshold value 1 during idle stop, it is determined that the voltage drop rate of the sub battery 42 is large, that is, the sub battery 42 has a voltage drop. As described above, even if an erroneous determination due to the influence of polarization occurs during the initial voltage determination of torque assist permission and the idle stop is permitted, the voltage determination of the idle stop permission is performed again during the idle stop. The idle stop is canceled. Further, since only the subsequent idle stop is canceled, torque assist that imposes a greater burden on the battery than the idle stop is also prohibited.

The above-described determination threshold value 1 during idling stop is searched from the sub-battery current Isb at the timing (t5, t10 in FIG. 6) when the predetermined time Y [ms] has elapsed from the idling stop start timing. By seeking. As shown in FIG. 19, the determination threshold value 1 during idling stop is a value that decreases as the sub-battery current increases after the elapse of Y from the start of idling stop. This is in accordance with the battery characteristics in which the sub battery voltage decreases as the sub battery current after the elapse of Y from the start of idle stop increases.

In FIG. 18, when the sub-battery voltage Vsb after the elapse of Y from the start of the idle stop is equal to or greater than the determination threshold value 1 during the idle stop in step 61, the process proceeds to step 64. In step 64, the main battery voltage Vmn [V] after the elapse of Y from the start of idle stop is compared with the determination threshold value 2 [V] during idle stop. When the main battery voltage Vmn after the elapse of Y from the start of the idle stop is less than the determination threshold value 2 during idle stop, it is determined that the main battery 41 has a large voltage drop rate, that is, the main battery 41 has a voltage drop. At this time, the routine proceeds to steps 62 and 63 to release the idle stop and prohibit the subsequent torque assist.

The reason for prohibiting the subsequent torque assist when the main battery voltage Vmn after the elapse of Y from the start of the idle stop is less than the determination threshold value 2 during idle stop is not the same as that of the sub battery 42 as described below.

After the first engine start, the main battery 4 is discharged by starting discharge from the start of idle stop.
The voltage of 1 drops. The voltage drop of the main battery 41 increases as the driver increases the load of the first electric load 44 using the main battery 41 as a power source, that is, as the power consumption of the main battery 41 by the device constituting the first electric load 44 increases. . If the torque assist is performed without considering the operation of each device constituting the first electric load 44, the operation of each device constituting the first electric load 44 cannot be guaranteed. Therefore,
The power consumption of the main battery 41 by the first electric load 44 is within a certain range (within a predetermined value).
If it falls within the range, a voltage at which torque assist can be performed at the same time (no need to perform an emergency stop of torque assist) is set as the determination threshold value 2 during idle stop. In other words,
If torque assist is permitted even when the main battery voltage Vmn is less than the determination threshold value 2 during idling stop, the operation of each device constituting the first electric load 44 cannot be guaranteed, and emergency stop of torque assist is stopped. Will be done.

Therefore, when the main battery voltage Vmn after the lapse of Y from the start of the idle stop is less than the determination threshold value 2 during the idle stop, by prohibiting the subsequent torque assist,
Avoid emergency stop of torque assist. In the emergency stop of the torque assist, the assist torque is returned stepwise from a constant value (100%) to zero (0%) (see the long broken line in the third stage in FIG. 16), so that a torque shock may occur. On the other hand, the torque assist permission voltage is determined again during the idle stop, and the subsequent torque assist is prohibited when the main battery 41 has a voltage drop, thereby avoiding the torque shock accompanying the emergency stop of the torque assist. Can do it.

The above-described determination threshold value 2 during idling stop is a table containing FIG. 20 from the main battery current Imn [A] at the timing (t5, t10 in FIG. 6) when the predetermined time Y [ms] has elapsed from the idling stop start timing. Find by searching. As shown in FIG. 20, the determination threshold value 2 during idling stop is a value that decreases as the main battery current increases after the elapse of Y from the start of idling stop. This is Y from the start of idle stop
This is in accordance with the battery characteristics in which the main battery voltage decreases as the main battery current after the lapse increases.

As described above, the operation of each device constituting the first electric load 44 is ensured for the main battery 41, and the emergency stop of the torque assist is performed so that the emergency stop of the torque assist is not performed. This avoids the torque shock that accompanies this.

Next, the reason for releasing the idle stop when the main battery voltage Vmn after the elapse of Y from the start of the idle stop is less than the determination threshold value 2 during idle stop is as follows. That is, when the sub battery voltage Vsb after the elapse of Y from the start of the idle stop is less than the determination threshold value 1 during idle stop, the idle stop is released, so that the main battery 41 is also handled in the same row as the sub battery 42. .

Unlike the sub-battery 42, the main battery 41 has no meaning to make the voltage determination again in a state where the influence of polarization is eliminated during the idle stop. For the main battery 41, it is not necessary to consider the influence of polarization. Regarding this, basically, the main battery 41 can also be polarized. However, for the main battery 41, the initial voltage determination for the idling stop permission and the initial voltage determination for the torque assist permission are performed at the determination timing during the initial start. During the initial startup, a large current flows from the main battery 41 toward the starter 6. That is, during the initial startup, a larger discharge than the main battery 41 is performed, and even if the main battery 41 is polarized by this discharge, the polarization is eliminated.

  The effect of this embodiment in the case of such a configuration will be described.

According to the present embodiment, the main battery 41 (first battery) used as a torque assist power source during torque assist, the sub battery 42 (second battery) used as a power source for electric loads other than torque assist during torque assist, A relay 43 (connecting / disconnecting means) for connecting / disconnecting the battery 41 and the sub-battery 42, and a relay 43 that is connected when torque assist is not performed, and a torque that performs torque assist after disconnecting the relay 43 when starting torque assist In a vehicle drive device including an assist execution means (51), an engine automatic stop for executing an idle stop (automatic engine stop) after disconnecting the relay 43 (connection / disconnection means) when an idle stop permission condition is satisfied. Execution means (51) and idle stop during idle stop When the engine release condition is satisfied, the engine automatic restarting means (51) that releases the idle stop (the engine is automatically restarted), and it is determined that there is a voltage drop in any of the batteries 41 and 42 during the idle stop. And torque assist prohibiting means (51) for prohibiting torque assist when it is performed. If the sub-battery 42 is discharged during idle stop, the influence of polarization is eliminated. For this reason, according to the present embodiment, when the initial voltage of the sub-battery 42 is determined, if the voltage is determined to be higher due to the polarization and the torque assist is permitted, the voltage drop during the idle stop eliminates the influence of the polarization. It will be. This makes it possible to correct erroneous determination due to polarization at the time of initial voltage determination without newly performing a diagnosis of whether or not polarization has occurred. In addition, according to the present embodiment, in the case where the torque assist emergency stop unit that immediately stops the torque assist due to the voltage drop during the torque assist is provided, the torque shock due to the torque assist emergency stop can be prevented.

When the sub-battery 42 starts discharging from the start of the idle stop, the influence of the polarization is eliminated at the timing when the predetermined time Y elapses from the start timing of the idle stop (after the predetermined time elapses). According to the present embodiment, the sub-battery voltage Vsb (second battery voltage) at the timing when the predetermined time Y elapses from the start timing of the idle stop (automatic engine stop) (after the predetermined time elapses) and the idling stop determination The threshold value 1 (determination threshold value) is compared, and when the sub battery voltage Vsb is less than the determination threshold value 1 during idling stop, it is determined that there is a voltage drop and torque assist is prohibited (see steps 61 and 63 in FIG. 18).
It is possible to perform voltage determination without the influence of polarization during idle stop. If the main battery voltage Vmn at the timing when the predetermined time Y has elapsed from the start timing of the idle stop is less than the determination threshold value 2 during idle stop, the torque assist is performed so that the first electric load 44 (first The operation of an electric load using a battery as a power source cannot be guaranteed. On the other hand, according to the present embodiment, the main battery voltage Vmn (the voltage of the first battery) and the idle stop at the timing when the predetermined time Y has elapsed from the start timing of the idle stop (automatic engine stop). The medium determination threshold value 2 (determination threshold value) is compared, and when the main battery voltage Vmn is less than the determination threshold value 2 during idle stop, it is determined that there is a voltage drop and torque assist is prohibited (steps 61 and 64 in FIG. 18). 6
3), the operation of the first electric load 44 (electric load using the first battery as a power source) can be guaranteed.

According to the present embodiment, the sub-battery 42 (second time) at the timing when the predetermined time X has elapsed from the switching timing of the ignition switch 71 from OFF to ON (after the predetermined time has elapsed).
When it is determined that there is a voltage drop in the battery), torque assist is prohibited and the sub-battery 42
Since it includes torque assist initial voltage permission / prohibition means for permitting torque assist when it is determined that there is no voltage drop in the (second battery) (see the flow in FIGS. 11 and 13), whether torque assist is prohibited or permitted. The initial voltage determination can be performed early.

According to the present embodiment, torque assist emergency stop means that immediately stops torque assist when a voltage drop exceeding the guaranteed voltage limit occurs in the main battery 41 (first battery) during torque assist (see the flow of FIG. 17). Therefore, the operation of the device constituting the first electric load 44 using the main battery 41 as a power source can be guaranteed.

If the sub-battery 42 is discharged during idle stop, the influence of polarization is eliminated. For this reason, in the case where the voltage is determined to be higher by the polarization and the idling stop is permitted when the initial voltage of the sub-battery 42 is determined, the voltage drop during the idling stop eliminates the influence of the polarization. According to the present embodiment, when it is determined that there is a voltage drop in the sub battery 42 (second battery) during idle stop (during automatic engine stop)
Since the idling stop (automatic engine stop) is released (see steps 61 and 62 in FIG. 18), it is possible to determine whether or not the sub-battery 42 at the time of initial voltage determination without performing a diagnosis of whether or not the sub-battery 42 is polarized. Misjudgment due to polarization can be eliminated

According to the present embodiment, any one of the batteries 41 at the timing when the predetermined time X has elapsed from the switching timing of the ignition switch 71 from OFF to ON (after the predetermined time has elapsed).
, 42 prohibits idle stop (automatic engine stop) when it is determined that there is a voltage drop, and permits engine idle stop (automatic engine stop) when it is determined that there is no voltage drop in any of the batteries 41, 42. Since the stop initial voltage prohibition / permission means is provided (refer to the flowcharts of FIGS. 7 and 9), it is possible to make an early determination on whether to prohibit or permit idle stop.

Each of the characteristics shown in FIG. 19 and FIG. 20 only shows a tendency with respect to current, and in actuality, each characteristic is determined by adaptation.

In the embodiment, the torque assist is prohibited when it is determined that there is a voltage drop in any battery during the idle stop. However, it is determined that the discharge current from any battery is excessive during the idle stop. When doing so, torque assist may be prohibited. For example, in FIG. 6, when the sub battery voltage Vsb at t5 and t10 is less than the torque assist initial determination threshold value 1, the sub battery discharge current exceeds the torque assist initial determination current threshold value 1 (not shown). . Therefore, in FIG. 6, t5, t1
When the sub battery discharge current at 0 exceeds the torque assist initial determination current threshold value 1, it is determined that the sub battery discharge current is excessive. On the other hand, when the sub-battery discharge current at t5 and t10 is equal to or smaller than the torque assist initial determination current threshold value 1, it is determined that the sub-battery discharge current is not excessive. Similarly, when the main battery discharge current at t5 and t10 exceeds the torque assist initial determination current threshold value 2, it is determined that the main battery discharge current is excessive. On the other hand, when the main battery discharge current at t5 and t10 is equal to or smaller than the torque assist initial determination current threshold value 2, it is determined that the main battery discharge current is not excessive. Here, it is conceivable that the torque assist initial determination current thresholds 1 and 2 are constant values. This constant value is determined in advance by adaptation.

For reference, changes in the sub-battery discharge current are shown at the bottom of FIG. In the lowermost part of FIG. 21, the vertical axis represents the current value increasing from the discharge on the basis of the state where charging / discharging is not performed. Therefore, an increase in the current value indicates that the sub-battery discharge current is large. When the discharge current threshold is taken as shown at the bottom of FIG. 21, when the sub battery discharge current exceeds the discharge current threshold, if the sub battery discharge current is excessive, the sub battery discharge current is equal to or lower than the discharge current threshold. It is determined that the sub battery discharge current is not excessive.

In the flow of FIG. 18 of the first embodiment, the description has been given of the case where the determination threshold values 1 and 2 during idle stop are determined depending on the sub battery voltage Vsb after Y has elapsed since the start of idle stop. 2 may be a constant value for simplicity.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 21 Motor generator 41 Main battery (1st battery)
42 Sub battery (second battery)
43 Relay (connection / disconnection means)
51 Engine control module (torque assist execution means, engine automatic stop execution means, engine automatic restart means, torque assist prohibition means)

The present invention aim is, motor generator use range by expanding the torque assist while the vehicle is traveling may drivability to Rutotomoni, that you provide a device capable of rectify first voltage determination incorrect due to polarization And

An apparatus according to an aspect of the present invention includes a motor mechanically coupled to an output shaft of an engine, a torque converter disposed between the engine and the transmission, having a lock-up clutch, and torque assisting the engine. And a motor control means for generating a predetermined assist torque in the motor, allowing torque assist when the lockup clutch is engaged, and providing torque assist when the lockup clutch is released. Ban. In this embodiment, a first battery used as a power source for the motor at the time of torque assist , a second battery used as a power source for an electric load other than the motor at the time of torque assist , and connection / disconnection means for connecting / disconnecting the first battery and the second battery; a torque assist execution means for executing the torque assist on cutting the disengaging means when torque assist, when a predetermined idle stop permission condition is satisfied, the self Dotoma stop of the engine on cutting the disengaging means and automatic engine stop execution means for executing, when a predetermined idle stop releasing condition during automatic stop of the engine is satisfied, the automatic engine restart means for automatically restarting the engine, during the automatic stop of the engine first and voltage drop exceeding a predetermined range to either the second battery is determined that either or the first and second battery noise If either of the discharge current is determined to exceeds the determination threshold, preferably further comprises a torque assist prohibiting means for prohibiting the torque assist after the restart of the engine, a.

According to the present invention, torque assist is allowed when the lock-up clutch is engaged, while torque assist is prohibited when the lock-up clutch is disengaged, thereby reducing torque transmission efficiency. Can be avoided. Further, according to the present invention, when the initial voltage of the second battery is determined, the voltage is determined to be higher by polarization , and torque assist is permitted, so that the second battery is discharged during automatic engine stop. Thus, the influence of polarization is eliminated. Therefore, the voltage drop during the automatic stop of the engine becomes the influence of the polarization is eliminated. This makes it possible to correct erroneous determination due to polarization at the time of initial voltage determination without newly performing a diagnosis of whether or not polarization has occurred.

Claims (9)

A first battery used as a torque assist power source during torque assist;
A second battery used as a power source for electric loads other than torque assist at the time of torque assist;
Connection / disconnection means for connecting / disconnecting the first battery and the second battery;
In a vehicle drive device comprising: the connecting / disconnecting means when not performing the torque assist; and the torque assist executing means for executing the torque assist after disconnecting the connecting / disconnecting means when starting the torque assist. ,
An engine automatic stop execution means for executing an automatic engine stop after disconnecting the connecting / disconnecting means when an idle stop permission condition is satisfied;
An engine automatic restarting means for automatically restarting the engine when an idle stop cancellation condition is satisfied during the engine automatic stop;
Torque assist prohibiting means for prohibiting the torque assist when it is determined that there is a voltage drop in any of the batteries during the automatic engine stop or when it is determined that the discharge current of any of the batteries is excessive. A drive device for a vehicle. The voltage of the second battery after a lapse of a predetermined time from the start timing of the engine automatic stop is compared with a determination threshold, and when the voltage of the second battery is less than the determination threshold, it is determined that there is a voltage drop and the torque assist The vehicle drive device according to claim 1, wherein The voltage of the first battery after a lapse of a predetermined time from the start timing of the automatic engine stop is compared with a determination threshold, and when the voltage of the first battery is less than the determination threshold, it is determined that there is a voltage drop and the torque assist The vehicle drive device according to claim 1, wherein When it is determined that there is a voltage drop in the second battery after a lapse of a predetermined time from the switching timing of the ignition switch from OFF to ON, the torque assist is prohibited, and when it is determined that there is no voltage drop in the second battery The vehicle drive device according to any one of claims 1 to 3, further comprising torque assist initial voltage permission / prohibition means for permitting torque assist. 5. A torque assist emergency stop means for immediately stopping the torque assist when a voltage drop exceeding a guaranteed voltage limit occurs in the first battery during the torque assist. The drive device of the vehicle as described in one. The engine automatic stop is canceled when it is determined that there is a voltage drop in the second battery during the automatic engine stop or when it is determined that the discharge current from the second battery is excessive. The vehicle drive device according to any one of claims 1 to 5. When it is determined that there is a voltage drop in any of the batteries after a lapse of a predetermined time from the switching timing of the ignition switch from OFF to ON, the automatic engine stop is prohibited and it is determined that there is no voltage drop in any of the batteries. 7. An engine automatic stop initial voltage prohibition / permission means for permitting the engine automatic stop when the engine is stopped is provided.
The vehicle drive device according to any one of the above. 2. The vehicle drive device according to claim 1, wherein the prohibition of torque assist is prohibition of torque assist immediately after an idle stop is released. The vehicle drive device according to claim 1, wherein the prohibition of torque assist is prohibition of all torque assist until the engine is stopped.

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