JP2013189134A - Drive device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device that can satisfy both improvement of fuel consumption and operability by expanding a motor generator to torque assist in travelling a vehicle.SOLUTION: A device includes: a motor generator (21) that is mechanically coupled to an output shaft (3) of an engine through transmission devices (23, 5) and collects the kinetic energy at vehicle deceleration as the electrical energy; a battery (41) that stores the electrical energy collected by this motor generator (21); a control means (51) that makes the motor generator (21) generate prescribed assist torque by using the battery (41) as power supply to perform torque assist of the engine; and a permission and inhibiting means (51) that permits torque assist by the control means (51) when there is an acceleration request after traveling start of the vehicle and prohibits the torque assist by the control means (51) when the acceleration request is lost during the permission of the torque assist.

Description

  The present invention relates to a vehicle drive device.

  There is a type in which a motor generator is mechanically coupled to an output shaft of an engine via a belt, and the engine is started by this motor generator (see Patent Document 1).

JP 2007-292079 A

  By the way, if the range in which the motor generator is used is not limited to engine start, but can be extended to torque assist during vehicle travel, it is desirable from the viewpoint of improving drivability and improving fuel efficiency. Invented by the present inventor.

  However, the technique disclosed in Patent Document 1 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.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that can improve both fuel efficiency and drivability by expanding the motor generator to torque assist during vehicle travel.

  A vehicle drive device according to the present invention is mechanically coupled to an output shaft of an engine via a transmission device and recovers kinetic energy at the time of vehicle deceleration as electric energy, and electric energy recovered by the motor generator is recovered. A battery for storing, and motor generator control means for generating a predetermined assist torque in the motor generator by using the battery as a power source so as to torque assist the engine. Furthermore, the vehicle drive device of the present invention permits torque assist by the control means when there is an acceleration request after the vehicle starts running, and torque assist by the control means when the acceleration request disappears while permitting torque assist. Torque assist permission / prohibition means for prohibiting

  According to the present invention, if there is a driver's intention to accelerate (acceleration request) after the vehicle starts running, torque assist by the motor generator using regenerative energy is permitted, and if the driver's intention to accelerate disappears during torque assist, the torque assist is performed. Is prohibited, so that the acceleration response after the vehicle starts running is improved. Moreover, the motor generator is used to recover the kinetic energy during vehicle deceleration as electric energy, the electric energy collected by the motor generator is stored in a battery, and the motor generator is driven using this battery as a power source, so there is no fuel consumption. Therefore, fuel consumption is improved. In this way, it is possible to achieve both improved fuel efficiency and good acceleration response (drivability).

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 the engine restart of 1st Embodiment. It is a flowchart for demonstrating the torque assist of 1st Embodiment. It is a timing chart from the engine restart of 2nd Embodiment. It is a flowchart for demonstrating the torque assist of 2nd Embodiment. It is a timing chart from the engine restart of 3rd Embodiment. It is a flowchart for demonstrating the torque assist of 3rd Embodiment.

  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. That is, 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. 23 and 33 are attached. A belt 5 is wound around each of the three pulleys 3, 23, 33, and power is transmitted (conducted) between the output shaft 3 and the rotary shafts 23, 33 of the engine 2 by the belt 5. Here, a belt transmission device including a belt and a pulley is shown, but a transmission device using a gear and a chain instead of the belt and the pulley may be used.

  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 14V batteries. The two batteries 41 and 42 are connected by two relays 43 arranged in parallel.

  Since the starter 6 and the motor generator 21 are electric loads that can tolerate a voltage drop, they are connected between the main battery 41 and the relay 43, and power is supplied from the main battery 41. In addition, since the motor generator 21 is comprised from the alternating current machine, the inverter 24 which converts the direct current from the main battery 41 into alternating current is attached.

  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 receives an accelerator opening signal (amount of depression of the accelerator pedal 52) from the accelerator sensor 53, a crank angle signal from the crank angle sensor 54, and an intake air amount signal from the air flow meter 55. ing. From the signal of the crank angle sensor 54, the rotational speed of the engine 2 is calculated. The engine control module 51 calculates the target intake air amount and the target fuel injection amount based on these signals, and instructs the throttle motor 13 and each fuel injection valve 7 to obtain the target intake air amount and the target fuel injection amount. Put out.

  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, when the accelerator pedal 52 is not depressed (APO = 0), the brake pedal 57 is depressed (brake switch 58 is ON), and the vehicle 1 is in a stopped state (vehicle speed VSP = 0), idle stop is performed. The permission condition is satisfied. 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 by 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 33 to electrically disconnect the main battery 41 and the sub battery 42. 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.

  The vehicle 1 also includes a vehicle dynamics control unit 62, a vehicle speed sensitive electric power steering control unit 63, an air conditioner auto amplifier 64, and a combination meter 66. 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.

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

  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 traveling of the vehicle, it is desirable from the viewpoint of improving fuel efficiency and the drivability is improved. Came to mind.

  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 when there is an acceleration request after the engine 2 is restarted from the idle stop and after the vehicle 1 starts running, and when there is no acceleration request while the torque assist is permitted, the torque is Assist is prohibited.

  When permitting torque assist, a predetermined assist torque is generated in the motor generator 21 using the main battery 41 as a power source so as to assist the torque of the engine 2, 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 voltage 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 by a LIN (Local Internet 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 torque assist performed using the motor generator 21 when there is an acceleration request 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.

  The idle stop permission condition is not satisfied at the timing t1, and the engine 2 is cranked using the motor generator 21, and the fuel injection from the fuel injection valve 7 and the spark ignition by the spark plug are restarted. As a result, if the engine 2 starts combustion, the engine speed rapidly increases, but it is determined that the engine 2 has been restarted at the timing t2 that crosses the predetermined complete explosion speed.

  On the other hand, since the driver (driver) slightly depresses the accelerator pedal 52 near t2, the fuel injection amount (Tp) from the fuel injection valve 7 and the air intake air amount Qa increase. As a result, the engine rotational speed increases and the vehicle torque (= engine torque) increases, so that the vehicle 1 starts traveling from the timing t3 and the vehicle speed slowly increases. 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 timing t5, the accelerator opening APO increases. At time t6 when the accelerator opening APO reaches the accelerator opening threshold APOOK, it is determined that there is a driver acceleration request, and a 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 (torque assist), and 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. When the need arises, that is, when there is an acceleration request, if the motor generator 21 generates assist torque using the main battery 41 that stores this electric energy as a power source, fuel is not consumed. 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 time intervals (for example, every 10 ms).

  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 to check whether the vehicle 1 is traveling. 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 both 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, torque assist is permitted when the SOC of the main battery 41 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 both the above conditions <1> and <2> are not 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, if either of the above conditions <1> or <2> is satisfied, it is determined that the torque assist permission condition is not satisfied, and the routine proceeds to step 6 where the torque assist permission flag = 0.

  In step 7, the torque assist permission flag is again checked. When the torque assist permission flag = 1, the routine proceeds to step 8 where the accelerator opening APO detected by the accelerator sensor 53 is compared with the accelerator opening threshold APOOK. The accelerator opening threshold APOOK is a value for determining whether or not there is a driver acceleration request, and is determined in advance. When the accelerator opening APO is equal to or greater than the accelerator opening threshold APOOK, it is determined that there is an acceleration request. 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 the motor torque is added to the engine torque with good response at the timing of t6.

  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 increase from the maximum torque to zero.

  The period during which the torque assist is performed (that is, the period during which the maximum current is supplied to the inverter 24) is a fixed 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 accelerator opening APO is less than the accelerator opening threshold APOOK in step 8, it is determined that there is no acceleration request, 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 accelerator opening APO is returned to less than the accelerator opening threshold APOOK, assuming that the driver has achieved the desired acceleration by the acceleration while the vehicle is running, the torque assist execution flag = 0, and the torque assist by the motor generator 21 is performed. It is forbidden. When the driver has an intention to accelerate after the vehicle starts running, torque assist is executed. When the driver does not intend to accelerate during torque assist and the driver returns the accelerator pedal 52, the torque assist is prohibited. Thereby, there is no sense of incongruity and it is possible to achieve both improved fuel efficiency and good acceleration response (driability). 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 that is mechanically coupled to the output shaft 3 of the engine 2 via a transmission device (23, 5) and collects kinetic energy during deceleration of the vehicle as electric energy, and the motor generator 21 A battery 41 for storing the collected electrical energy, a motor generator control means (51) for generating a predetermined assist torque in the motor generator 21 using the battery 41 as a power source so as to assist the torque of the engine 2, and a start of running of the vehicle 1 Torque assist by the control means (51) is permitted when there is a request for acceleration later, and torque assist permission / inhibition means (51) for prohibiting torque assist by the control means (51) when there is no acceleration request while permitting torque assist. ). According to the present embodiment, if there is a driver's intention to accelerate (acceleration request) after the vehicle 1 starts running, torque assist by the motor generator 21 using regenerative energy is permitted, and if the driver's intention to accelerate disappears during torque assist. Since the torque assist is prohibited (see steps 8 to 10 in FIG. 4), the acceleration response after the start of vehicle travel is improved. In addition, the motor generator 21 is used to recover the kinetic energy at the time of vehicle deceleration as electric energy, the electric energy recovered by the motor generator 21 is stored in the battery 41, and the motor generator 21 is driven using the battery 41 as a power source. There is no fuel consumption and therefore fuel efficiency is improved. In this way, it is possible to achieve both improved fuel efficiency and good acceleration response (drivability).

  According to the present embodiment, the predetermined assist torque gradually increases from zero by allowing the torque assist to become a constant value or the maximum torque of the motor generator, and is constant by prohibiting the torque assist while the torque assist is permitted. Alternatively, since it gradually increases from the maximum torque of the motor generator to zero, it is possible to prevent torque shock due to application of assist torque in the low engine speed range where the engine is likely to feel driving shock.

  According to this embodiment, the throttle valve 12 that can adjust the amount of intake air introduced into the engine 2 according to the accelerator opening APO is provided, and when there is an acceleration request after the vehicle 1 starts running, the accelerator opening APO Is greater than or equal to a predetermined threshold value APOOK (see steps 8 and 9 in FIG. 4), and when the acceleration request disappears while permitting torque assist, the accelerator opening APO becomes less than the threshold value APOOK ( 4 (see steps 8 and 10 in FIG. 4), it is possible to permit / inhibit torque assist according to the accelerator opening APO.

  According to the present embodiment, the motor generator 21 mechanically coupled to the output shaft 3 of the engine 2 via the transmission device (23, 5) and recovers kinetic energy at the time of vehicle deceleration as electric energy, and the motor generator A battery 41 for storing electrical energy collected by the motor 21, a motor generator control means (51) for generating a predetermined assist torque in the motor generator 21 using the battery 41 as a power source so as to torque assist the engine 2, and an idle stop permission. An idle stop / restart means (51) for stopping the engine 2 when the condition is satisfied, and restarting the engine 2 using the motor generator 21 when the idle stop permission condition is not satisfied while the engine is stopped. The engine 2 is restarted by the motor generator 21 Torque assist by the control means (51) is permitted when an acceleration request is made after the vehicle 1 starts running, and torque assist by the control means (51) is prohibited when there is no acceleration request while the torque assist is permitted. Since the vehicle is provided with the permission / prohibition means (51), it is possible to achieve both improvement in fuel efficiency and good acceleration response (driving performance), as well as a vehicle that already has the motor generator 21 and the idle stop / restarting means (51). For example, since it can be dealt with only by changing the specifications of the motor generator 21 and simple software changes, it is possible to avoid a significant increase in cost.

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

(Second Embodiment)
FIG. 5 is a timing chart from engine restart of the second embodiment, and FIG. 6 is a flowchart of the second embodiment. The same parts as those in FIGS. 3 and 4 of the first embodiment are described in the same way.

  In the first embodiment, the accelerator opening APO is used as a parameter data for determining whether or not there is an acceleration request after the engine 2 is restarted and after the vehicle 1 starts running. On the other hand, in the second embodiment, a cylinder air amount equivalent pulse width Tp (a value equivalent to the fuel injection amount) is used as a parameter for determining whether or not there is an acceleration request after the engine 2 is restarted and after the vehicle 1 starts running. ).

  The difference from the first embodiment will be mainly described. As shown in FIG. 5, the acceleration of the driver at the timing of t6 ′ when the cylinder air amount equivalent pulse width Tp reaches the threshold TpOK of the cylinder air amount equivalent pulse width. Judge that there is a request. At this time, current from the main battery 41 is supplied to the inverter 24 to cause the motor generator 21 to generate motor torque. As a result, the motor torque is added to the engine torque (torque assist), and the acceleration desired by the driver is obtained.

  As shown in FIG. 6, in step 11, the cylinder air amount equivalent pulse width Tp [ms] is compared with the cylinder air amount equivalent pulse width threshold TpOK [ms]. Here, the cylinder air amount equivalent pulse width Tp is calculated based on the intake air amount Qa and the engine rotational speed Ne as described above in the fuel injection control. The cylinder air amount equivalent pulse width threshold TpOK is a value for determining whether or not there is an acceleration request, and is determined in advance. When the cylinder air amount equivalent pulse width Tp is equal to or greater than the threshold value TpOK, it is determined that there is an acceleration request, and the process proceeds to step 9 to execute torque assist, and the torque assist execution flag = 1 is set.

  On the other hand, when the cylinder air amount equivalent pulse width Tp is less than the threshold value TpOK in step 11, it is determined that there is no acceleration request, and the process proceeds to step 10 to set the torque assist execution flag = 0.

  Thus, according to the second embodiment, the fuel injection amount calculating means (51) for calculating the fuel injection amount (cylinder air amount equivalent pulse width Tp) according to the operating condition of the engine 2, and the calculated fuel injection amount. And the fuel injection valve 7 that intermittently supplies the fuel to the engine, and when there is an acceleration request after the vehicle 1 starts running, the fuel injection amount (Tp) is equal to or greater than a predetermined threshold TpOK (FIG. 6). Steps 11 and 9 of FIG. 6) When the acceleration request is canceled while the torque assist is permitted, the fuel injection amount (Tp) is less than the threshold value TpOK (see Steps 11 and 10 in FIG. 6). Torque assist can be permitted or prohibited according to the fuel injection amount (Tp).

(Third embodiment)
FIG. 7 is a timing chart from the engine restart of the third embodiment, and FIG. 8 is a flowchart of the third embodiment. The same parts as those in FIGS. 3 and 4 of the first embodiment are described in the same way.

  In the third embodiment, the intake air amount Qa is used as a parameter data for determining whether or not there is an acceleration request after the engine 2 is restarted and after the vehicle 1 starts running.

  The difference from the first embodiment will be mainly described. As shown in FIG. 7, it is determined that there is a driver acceleration request at timing t6 ″ when the intake air amount Qa reaches the intake air amount threshold value QaOK. To do. At this time, current from the main battery 41 is supplied to the inverter 24 to cause the motor generator 21 to generate motor torque. As a result, the motor torque is added to the engine torque (torque assist), and the acceleration desired by the driver is obtained.

  As shown in FIG. 8, in step 21, the intake air amount Qa is compared with the intake air amount threshold value QaOK. Here, the intake air amount Qa is calculated from the output of the air flow meter 55 as described above in the control of fuel injection. The intake air amount threshold value QaOK is a value for determining whether or not there is an acceleration request, and is determined in advance. When the intake air amount Qa is equal to or greater than the threshold value QaOK, it is determined that there is an acceleration request, and the process proceeds to step 9 to execute torque assist and sets the torque assist execution flag = 1.

  On the other hand, when the intake air amount Qa is less than the intake air amount threshold value TpOK in step 21, it is determined that there is no acceleration request, and the process proceeds to step 10 to set the torque assist execution flag = 0.

  Thus, according to the third embodiment, the fuel injection amount calculating means (51) for calculating the fuel injection amount (cylinder air amount equivalent pulse width Tp) according to the intake air amount Qa, and the calculated fuel injection amount ( And a fuel injection valve 7 that intermittently supplies (Tp) to the engine, and when there is an acceleration request after the vehicle 1 starts running, when the intake air amount Qa is equal to or greater than a predetermined threshold value QaOK (FIG. 8). Steps 21 and 9 in FIG. 8), when the acceleration request is canceled while the torque assist is permitted, the intake air amount Qa is less than the threshold value QaOK (see Steps 21 and 10 in FIG. 8). It is possible to permit / prohibit torque assist according to the amount Qa.

1 Vehicle 2 Engine 5 Belt (part of transmission device)
7 Fuel injection valve 12 Throttle valve 21 Motor generator 23 Pulley (part of transmission device)
41 Main battery (battery)
51 Engine control module (motor generator control means, torque assist permission / prohibition means, idle stop / restart means, fuel injection amount calculation means)
61 Control unit for automatic transmission (lock-up clutch control means)
62 Vehicle Dynamic Control Unit (Vehicle Behavior Control Device)
63 Vehicle Speed Sensitive Power Steering Control Unit (Vehicle Behavior Control Device)

Claims (8)

A motor generator mechanically coupled to the output shaft of the engine via a transmission device and recovering kinetic energy during vehicle deceleration as electric energy;
A battery for storing the electrical energy recovered by the motor generator;
Motor generator control means for generating a predetermined assist torque in the motor generator using the battery as a power source so as to torque assist the engine;
Torque assist permission / inhibition means for permitting torque assist by the control means when there is an acceleration request after the start of running of the vehicle, and prohibiting torque assist by the control means when the acceleration request disappears while permitting torque assist; A vehicle drive device comprising:   The predetermined assist torque gradually increases from zero when the torque assist is permitted to become a constant value or the maximum torque of the motor generator, and is constant or the maximum torque of the motor generator when the torque assist is prohibited while the torque assist is permitted. The vehicle drive device according to claim 1, wherein the vehicle drive device gradually increases from zero to zero. With a throttle valve that can adjust the amount of intake air introduced into the engine according to the accelerator opening,
When there is an acceleration request after the vehicle starts running, when the accelerator opening is equal to or greater than a predetermined threshold value, or when the acceleration request is lost while permitting torque assist, the accelerator opening is The vehicle drive device according to claim 1, wherein the vehicle drive device is a time when it becomes less than the threshold value. Fuel injection amount calculating means for calculating the fuel injection amount in accordance with engine operating conditions;
A fuel injection valve that intermittently supplies the calculated fuel injection amount to the engine,
When there is an acceleration request after the vehicle starts running, when the fuel injection amount becomes equal to or greater than a predetermined threshold, or when the acceleration request disappears while the torque assist is permitted, the fuel injection amount is The vehicle drive device according to claim 1, wherein the vehicle drive device is a time when it becomes less than the threshold value. Fuel injection amount calculating means for calculating the fuel injection amount according to the intake air amount;
A fuel injection valve that intermittently supplies the calculated fuel injection amount to the engine,
When there is an acceleration request after the vehicle starts running, when the intake air amount is equal to or greater than a predetermined threshold, or when the acceleration request disappears while the torque assist is permitted, the intake air amount is The vehicle drive device according to claim 1, wherein the vehicle drive device is a time when it becomes less than the threshold value. A motor generator mechanically coupled to the output shaft of the engine via a transmission device and recovering kinetic energy during vehicle deceleration as electric energy;
A battery for storing the electrical energy recovered by the motor generator;
Motor generator control means for generating a predetermined assist torque in the motor generator using the battery as a power source so as to torque assist the engine;
An idle stop / restart means for stopping the engine when the idle stop permission condition is satisfied, and for restarting the engine using the motor generator when the idle stop permission condition is not satisfied while the engine is stopped;
Torque assist by the control means is permitted when there is an acceleration request after the engine is restarted by the motor generator and after the vehicle starts running, and torque assist by the control means when the acceleration request disappears while permitting torque assist. Torque assist permission / prohibition means for prohibiting the motor drive device. A vehicle behavior control device for controlling the behavior of the vehicle,
The vehicle drive device according to claim 6, wherein the torque assist is not permitted when these devices are operating. A torque converter interposed between an engine output shaft and a belt-type automatic transmission, and having a pump impeller and a turbine runner;
A mechanical lock-up clutch that connects and disconnects the pump impeller and the turbine runner;
Lockup clutch control means for connecting the lockup clutch when a certain vehicle running condition is established, and
7. The vehicle drive device according to claim 6, wherein the torque assist is not permitted when the lock-up clutch control means is not connected to the lock-up clutch.

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