JP2001158254A - Controller for front and rear wheel drive vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a front and rear wheel drive vehicle capable of achieving superior energy efficiency and fuel consumption in traffic tie-up traveling. SOLUTION: The driving of front wheels 66, 68 by an engine 14 or a MG1 is switched to the driving of rear wheels 80, 82 exclusively by a MG2 by a motor switching control means 132, simultaneously with releasing a power transmission path from the engine 14 to front wheels 66, 68 through a planetary gear device 18 and a continuously variable transmission 20 by a power transmission path releasing control means to obtain the non-power transmission state, in the case that the traffic tie-up driving of a vehicle is judged by a traffic tie-up travel judging means 128, whereby the engine 14 or the MG1 is separated from the front wheels 66, 68, and a front and rear wheel drive vehicle is driven by the rear wheels 80, 82 directly driven exclusively by the MG2, which provides superior energy efficiency and fuel consumption in the traffic tie-up traveling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front-wheel drive vehicle provided with a first prime mover for driving one of the front and rear wheels and a second prime mover for driving the other wheel. The present invention relates to a control device for controlling.

[0002]

2. Description of the Related Art There is known a front-rear wheel drive vehicle in which one of a front wheel and a rear wheel is driven by a first prime mover via a transmission, and the other wheel is driven by a second prime mover. For example, a front and rear wheel drive vehicle described in Japanese Patent Application Laid-Open No. 9-298802 is a vehicle in which an electric motor functioning as a second prime mover is operated according to a vehicle state during operation of an engine functioning as a first prime mover. A driving force is added. Such conventional front and rear wheel drive vehicles operate an electric motor that drives the other wheel to supplement the driving force of one wheel driven by the engine, or when a braking request is made or an obstacle is detected. By operating an electric motor, a vehicle speed increase during braking is suppressed or approaching an obstacle is suppressed, so that braking performance and drivability are improved.

[0003]

However, in the above-mentioned conventional front-wheel drive vehicle, it merely supplements the driving force or improves the braking performance and drivability, and the vehicle frequently starts and stops or runs at low speed. No consideration was given to repeated traffic jams. Therefore, it cannot be said that the energy efficiency and the fuel efficiency during the traffic congestion are sufficiently obtained, and the energy efficiency and the fuel efficiency are limited.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control apparatus for a front-rear wheel drive vehicle that can obtain high energy efficiency and fuel efficiency during traffic congestion. .

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of a first invention is to provide a first prime mover capable of driving one of front and rear wheels via a transmission. A control device for a front and rear wheel drive vehicle having a second prime mover capable of driving the other wheel, comprising: (a) congestion traveling determination means for determining congestion traveling of the front and rear wheel drive vehicle; When traffic congestion traveling is determined by the traveling determination means,
Power transmission path release control means for releasing a power transmission path from the first prime mover to one wheel via the transmission to make a non-power transmission state, and (c) traffic congestion traveling by the traffic congestion determination means. If it is determined, a motor switching control means for switching from driving of one wheel by the first motor to driving of the other wheel by the second motor is included.

[0006]

In this way, when traffic congestion is determined by the traffic congestion determining means, the power transmitted from the first prime mover to one of the wheels via the transmission is transmitted by the power transmission path release control means. At the same time that the transmission path is released to be in the non-power transmission state, the driving of the first wheel is switched from the driving of one wheel by the first motor to the driving of the other wheel by the second motor by the motor switching control means. Since the front and rear wheel drive vehicles are driven by the other wheels that are separated from one wheel and exclusively driven by the second prime mover, high energy efficiency and fuel efficiency can be obtained during traffic jam driving.

[0007]

In another preferred embodiment of the present invention, there is provided acceleration operation determining means for determining whether or not the driver has performed an acceleration operation, and the second wheel prime mover drives the other wheel exclusively. If the driver's acceleration operation is determined by the acceleration operation determination means during the operation, the power transmission path release control means switches the power transmission path from the non-power transmission state to the power transmission enabled state, and switches the prime mover. The control means causes one of the wheels to be driven by the first prime mover and the other to be driven by the second prime mover. With this configuration, when the acceleration operation is performed while the vehicle is congested solely by the second prime mover, the front wheels and the rear wheels are driven by the first prime mover and the second prime mover, so that a sufficient driving force can be obtained. can get.

Preferably, the prime mover switching control means sets the first power transmission path to a power transmission state by the power transmission path release control means until a predetermined time elapses. 1 prime mover and 2nd
The front and rear wheels are driven by the prime mover, and after a predetermined time has elapsed, one of the wheels is driven by the first prime mover. Preferably, the second prime mover outputs the assist torque from the other wheel until the predetermined time elapses. With this configuration, when switching to the power transmission enabled state by the engagement of the friction engagement device inserted in the power transmission path, the predetermined time during which the power is not sufficiently transmitted during the engagement transition period of the friction engagement device In a state before the lapse, the other wheel is driven by the second prime mover,
Then, the assist torque is output, so that the uncomfortable feeling at the time of the acceleration operation is eliminated and a good acceleration response is obtained.

[0009] Preferably, a generator driven by the first prime mover is provided, and the second prime mover is an electric motor. In the congested traveling, an output from the generator driven by the first prime mover is provided. The electric power supplied to the electric motor drives the vehicle.
According to this configuration, the electric power output from the generator driven by the first prime mover is supplied to the electric motor during traffic congestion, so that the other wheel is driven to rotate. Therefore, regardless of the capacity of the power storage device, There is an advantage that you can travel in traffic.

[0010] Preferably, the power storage device further includes a power storage device for storing power, and a power storage amount determining means for determining whether the power storage amount of the power storage device is equal to or less than a predetermined reference value. When the storage amount determination unit determines that the storage amount of the power storage device is equal to or more than the determination reference value, the power stored in the power storage device is supplied to the motor, and the power storage amount of the power storage device is determined. If it is determined that the value is smaller than the determination reference value, the electric power output from the generator driven by the first prime mover is supplied to the electric motor. In this way, during traffic congestion, the first
When the power output from the generator driven by the prime mover is supplied to the motor, the other wheel is driven to rotate. There is an advantage that the vehicle can travel in congested traffic even when the state of charge is insufficient.

Preferably, when the first prime mover is an engine, and when the power transmission path is switched from a non-power transmission state to a power transmission state by engagement of a friction engagement device inserted therein, For example, since the engine load suppressor for temporarily reducing the throttle valve opening by a predetermined amount is provided by temporarily increasing the electric load of a generator driven by the engine, or in addition to the above, the friction The engine is prevented from blowing up during the transition period of the engagement of the joint device.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a skeleton diagram for explaining the configuration of a power transmission device of a four-wheel drive vehicle, that is, a front-rear wheel drive vehicle to which the present invention is applied. This front and rear wheel drive vehicle is a so-called hybrid vehicle having an internal combustion engine and an electric motor as prime movers, in which a front wheel system is driven by a first drive device having a first prime mover, that is, a main drive device 10, and a rear wheel system is driven. This is a driving device of a type driven by a second driving device having a second prime mover, that is, a sub driving device 12.

The main drive unit 10 includes an engine 14, which is an internal combustion engine that is operated by burning a mixture of air and fuel, and a motor generator MG1 (hereinafter, referred to as a first motor and a generator). , MG1), a double pinion type planetary gear set 18 and a continuously variable transmission 20 whose gear ratio can be continuously changed. The engine 14 and / or
Alternatively, MG1 functions as a first prime mover, that is, a main prime mover. The engine 14 includes a throttle actuator 21 that drives the throttle valve 19 to change the opening degree θ _TH of the throttle valve 19 that controls the amount of intake air in the intake pipe.

The planetary gear set 18 is a composite distribution mechanism for mechanically synthesizing or distributing a force, and includes three rotating elements which are independently rotatable around a common axis, ie, the engine. And a sun gear 24 connected to the input shaft 26 of the continuously variable transmission 20 via a first clutch C1.
And a ring gear 32 connected to the input shaft 26 of the continuously variable transmission 20 via the second clutch C2 and connected to a non-rotating member such as the housing 30 via the brake B1. It has. The carrier 28 rotatably supports a pair of pinions (planetary gears) 34 and 36 that mesh with and mesh with the sun gear 24 and the ring gear 32. Each of the first clutch C1, the second clutch C2, and the brake B1 is engaged by being pressed by a plurality of friction plates superimposed on each other by a hydraulic actuator, and is released by releasing the pressing. It is a type friction engagement device.

The planetary gear set 18 and its carrier 28
Is controlled in the operating state of the engine 14, that is, the rotation state of the sun gear 24, that is, generated on the carrier 28 so that the reaction force, which is the rotational driving torque of the MG 1, gradually increases. As a result, an electric torque converter (ETC) device that enables the vehicle to smoothly start and accelerate by increasing the rotation speed of the ring gear 32 smoothly is configured. At this time, the gear ratio ρ of the planetary gear unit 18 (the number of teeth of the sun gear 24 / the ring gear 3
For example, if the number of teeth of 2 is 0.5, which is a general value, the torque of the ring gear 32: the torque of the carrier 28:
From the relationship of torque of sun gear 24 = 1 / ρ: (1−ρ) / ρ: 1, the torque of engine 14 is 1 / ρ times, for example, 2
Since it is amplified twice and transmitted to the continuously variable transmission 20, it is called a torque amplification mode.

The continuously variable transmission 20 has an input shaft 26.
The output shaft 38 includes a pair of variable pulleys 40 and 42 having variable effective diameters, and an endless annular transmission belt 44 wound around the pair of variable pulleys 40 and 42. These pair of variable pulleys 4
0 and 42 are fixed rotating bodies 46 and 48 fixed to the input shaft 26 and the output shaft 38, respectively, and the input shaft 26 and the output shaft 38 are formed so as to form a V groove between the fixed rotating bodies 46 and 48. Movable body 5 that is movable in the axial direction with respect to and is mounted so as not to rotate relative to the axial center.
0 and 52, and the movable rotators 50 and 52 are given thrust to change the engaging diameters, that is, the effective diameters of the variable pulleys 40 and 42, thereby changing the gear ratio γ (= input shaft rotation speed / output shaft rotation speed). It has a pair of hydraulic cylinders 54 and 56 to be changed.

The torque output from the output shaft 38 of the continuously variable transmission 20 is transmitted to a pair of front wheels 66, 6 via a reduction gear 58, a differential gear device 60, and a pair of axles 62, 64.
8. In this embodiment, a steering device for changing the steering angle of the front wheels 66 and 68 is omitted.

The sub drive unit 12 includes a rear motor generator MG2 (hereinafter, referred to as MG2) functioning as a sub prime mover, a second prime mover, or a generator. The torque output from the MG 2 is reduced by a reduction gear 72, Gear device 7
4, and a pair of rear wheels 8 via a pair of axles 76, 78.
0, 82.

FIG. 2 is a diagram illustrating the configuration of a control device provided in the front and rear wheel drive vehicle of the present embodiment. Engine control device 100, shift control device 102, hybrid control device 104, power storage control device 106, brake control device 1
Reference numeral 08 denotes a so-called microcomputer having a CPU, a RAM, a ROM, and an input / output interface.
U processes input signals according to a program stored in the ROM in advance while using the temporary storage function of the RAM, and executes various controls. Further, the above-mentioned control devices are communicably connected to each other, and when a required signal is requested from a predetermined control device, the signal is appropriately transmitted from another control device to the predetermined control device. ing.

The engine control device 100 includes the engine 14
Execute engine control. For example, a fuel injection valve (not shown) is controlled for controlling the fuel injection amount, an igniter (not shown) is controlled for controlling the ignition timing, and a throttle corresponding to the actual operation amount Acc of the accelerator pedal 96 is determined from a preset relationship. The throttle actuator 21 is controlled to obtain the valve opening degree θ _TH . The shift control device 102 includes:
For example, from a relationship set in advance so that the tension of the transmission belt 44 of the continuously variable transmission 20 becomes a necessary and sufficient value,
Actual gear ratio γ and transmission torque, ie, engine 14
And a pressure regulating valve that regulates the belt tension pressure based on the output torque of MG1 so that the tension of the power transmission belt 44 is set to an optimum value and the engine 14 operates along the minimum fuel consumption rate curve or the optimum curve. The target gear ratio γ _m is determined based on the actual vehicle speed V and the engine load, for example, the throttle valve opening θ _TH expressed as the throttle opening θ or the operation amount A _CC of the accelerator pedal 96 from the relationship stored in advance. , The actual speed ratio γ is the target speed ratio γ
The gear ratio γ of the continuously variable transmission 20 is controlled so as to match _m .

The hybrid control device 104 controls a first MG for controlling a driving current supplied from the power storage device 112 including a battery or the like to the MG1 or a generated current output from the MG1 to the power storage device 112. MG from control device 116 and power storage device 112
11 that controls drive current supplied to power supply 2 or generated current output from MG 2 to power storage device 112
8, a second MG control device 120 for controlling the
Shift lever 98 operating position P _SH , throttle opening θ
Based on (the throttle valve opening or the operation amount A _cc of the accelerator pedal 96), the vehicle speed V, and the state of charge SOC of the power storage device 112, for example, one of a plurality of operation modes shown in FIG. , The throttle opening θ, and the operation amount _BF of the brake pedal 94, the MG
1 or a regenerative braking mode in which a braking force is generated by a torque required for power generation by the MG 2 or an engine brake mode in which a braking force is generated by a rotational resistance torque of the engine 14.

When the shift lever 98 is operated to the B range or the D range, for example, when starting with a relatively low load or traveling at a low speed, the motor traveling mode is selected, the first clutch C1 is engaged, and the second clutch C2 is engaged. By releasing both brake and brake B1, the vehicle is driven exclusively by MG1. In this motor running mode, when the state of charge SOC of the power storage device 112 becomes insufficient below a lower limit set in advance, or when the engine 14 is started to require more driving force, Is switched to the ETC mode or the direct connection mode, and the MG1 or MG
2 is driven, and the power storage device 112 is charged by the MG1 or MG2.

When the vehicle is running under a relatively medium load or a high load, the direct connection mode is selected, the first clutch C1 and the second clutch C2 are both engaged, and the brake B1 is released, so that the planetary gear unit 18 is driven. The vehicle is driven integrally by the engine 14 or exclusively by the engine 14 and the MG 1, or at the same time when the vehicle is exclusively driven by the engine 14 and the MG 1
Charging of the power storage device 112 is performed. In this direct connection mode, the rotation speed of the sun gear 24, that is, the engine rotation speed N _E
(Rpm), the rotation speed of the carrier member 28, that is, the rotation speed N _MG (rpm) of the MG1, and the rotation speed of the ring gear 32, that is, the rotation speed N _IN (rpm) of the input shaft 26 of the continuously variable transmission 20, are the same value. From the above, in the two-dimensional plane, three rotation speed axes (vertical axis), that is, a sun gear rotation speed axis S, a ring gear rotation speed axis R, a carrier rotation speed axis C, and a transmission ratio axis (horizontal axis)
In the alignment chart of FIG. 4 drawn from the above, for example, the dashed line is shown. In FIG. 4, the distance between the sun gear rotation axis S and the carrier rotation axis C corresponds to 1, and the distance between the ring gear rotation axis R and the carrier rotation axis C is the double pinion type planetary gear device 18. It corresponds to the gear ratio ρ.

Also, for example, in starting acceleration traveling, ETC
Mode, that is, the torque amplification mode is selected, and the second
Clutch C2 is engaged and the first clutch C1 and the clutch
With the rake B1 both released, the power generation of MG1
Production amount), that is, the reaction force of MG1 (rotate MG1)
Drive torque) is gradually increased,
The vehicle slips while the gin 14 is maintained at the predetermined rotation speed.
Crab is launched zero. Thus, the engine 14
When the vehicle and the MG1 are driven by the
If the torque of 4 is 1 / ρ times, for example, ρ = 0.5, it is doubled
And is transmitted to the continuously variable transmission 20. That is,
Speed N of MG1_MGIs point A in FIG. 4 (negative rotation speed
Power generation state), the input shaft of the continuously variable transmission 20
Revolution N _INIs zero, the vehicle is stopped.
As shown by the dashed line in FIG.
The rotation speed N_MGIs changed to its positive point B
Accordingly, the input shaft speed N of the continuously variable transmission 20_INBut
It is increased and the vehicle is started.

When the shift lever 98 is operated to the N range or the P range, basically, the neutral mode 1
Or 2 is selected, the first clutch C1, the second clutch C2, and the brake B1 are all released, and the power transmission path in the planetary gear set 18 is released. In this state, for example, when the state of charge SOC of the power storage device 112 becomes insufficient below the lower limit set in advance, for example, the charging / engine start mode is set, and the brake B1 is engaged. The engine 14 is started by the MG1. When the shift lever 98 is operated to the R range, for example, in the light load reverse traveling, the motor traveling mode is selected, the first clutch C1 is engaged, and the second clutch C2 and the brake B1 are both released. The vehicle is made to travel backward only by MG1. However, for example, when the vehicle is traveling backward under a medium load or a high load, the friction traveling mode is selected and the first clutch C
1 is engaged, the second clutch C2 is released, and the brake B1 is slip-engaged. Thereby, the output torque of engine 14 is added to the output torque of MG1 as the driving force for moving the vehicle backward.

The hybrid control device 104
Operates the MG2 according to a predetermined driving force distribution ratio in order to temporarily increase the driving force of the vehicle when the vehicle starts or suddenly accelerates according to the driving force of the front wheels 66, 68,
High μ road assist control that also generates driving force from the rear wheels 80 and 82, and low friction coefficient roads (low μ road such as frozen roads and snow-covered roads)
At the time of start running on the road, the rear wheels 80 and 82 are driven by the MG2 and the front wheels 66 and 68 are driven by lowering the speed ratio γ of the continuously variable transmission 20 in order to increase the starting capability of the vehicle. The low μ road assist control for reducing the force is executed.

When the state of charge SOC of the power storage device 112 such as a battery or a capacitor falls below a preset lower limit SOC _O , the power storage control device 106 determines whether MG1 or MG
The power storage device 112 is charged or stored with the electric energy generated by the power generation unit 2. If the storage amount SOC exceeds a preset upper limit value SOC _U , the power storage device 112 is charged with the electric energy from the MG 1 or MG 2. Ban.

The brake control device 108 is, for example, TR
C control, ABS control, VSC control, etc., are performed via a hydraulic brake control circuit in order to increase the stability of the vehicle at the time of starting running, braking, turning at low μ road or the like, or to increase traction. Wheel brakes 66 _WB , 68 _WB , 80 _WB , 8 provided on wheels 66, 68, 80, 82
2 Control _WB . For example, based on a signal from a rotation sensor provided for each wheel, a wheel speed (a vehicle speed converted based on the wheel rotation speed) such as a right front wheel speed V _FR , a left front wheel speed V _FL , a right rear wheel Wheel speed V _RR , left rear wheel speed V _RL , front wheel speed [= (V _FR + V _FL ) / 2],
While calculating the rear wheel speed [= (V _RR + V _RL ) / 2] and the vehicle body speed (the slowest speed among V _FR , V _FL , V _RR and V _RL ), for example, the front wheels which are the main drive wheels When the slip speed ΔV, which is the difference between the vehicle speed and the rear wheel speed of the non-driving wheel, exceeds a preset control start determination reference value ΔV ₁ , a slip is determined for the front wheels, and the slip ratio R _S [= (ΔV
/ V _F ) × 100%] falls within the target slip ratio R _S1 , which is set in advance, and simultaneously decreases the output torque of the MG 1 using the wheel brakes 66 _WB and 68 _WB.
6, 68 drive force is reduced.

FIG. 5 shows the hybrid control device 104.
FIG. 2 is a functional block diagram for explaining a main part of a control function such as the above, and shows switching control of a motor during traffic congestion.

In FIG. 5, traffic congestion determination means 128
Indicates the traffic congestion of the front and rear wheel drive vehicle, for example, 20 km
The determination is made based on the fact that the vehicle is traveling at a predetermined throttle opening θ _X1 or less at a predetermined vehicle speed V _{X1 of} about / h or less and the number of stops and starts N per unit time is equal to or more than a predetermined value N _X1 . When the traffic congestion determination unit 128 determines that traffic congestion is traveling, the power transmission path release control unit 130
By disengaging the clutches C1 and C2, the front wheel power transmission path from the engine 14 to the front wheels 66, 68 which are one of the front and rear wheels via the planetary gear set 18 and the continuously variable transmission 20 is released, and Power transmission state. At the same time, the prime mover switching control unit 132 changes the driving of the front wheels 66 and 68 by the engine 14 to the rear wheels 80 and 8 by the MG2.
2 and the vehicle is driven exclusively by MG2 during traffic congestion.

The acceleration operation determining means 134 determines whether or not the high additional running state is selected, that is, whether or not the driver has performed an acceleration operation, for example, by determining the throttle opening θ from the value θ _{tx in the} previous control cycle. It is determined based on whether or not it has increased. When the acceleration operation is determined by the acceleration operation determination means 134, the power transmission path release control means 130 can transmit power from the non-power transmission state to the power transmission path by engaging the clutches C1 and C2. The engine 14 and the MG 2 to control the front wheels 6.
6, 68 and the rear wheels 80, 82 are driven together. At this time, the prime mover switching control means 132 sets the clutches C1 and C1 after the power transmission path release control means 130 starts to switch the power transmission path to the power transmittable state.
Until a predetermined time t _{1, which} is set in advance about the engagement operation time of _{No. 2,} has elapsed, in order to quickly generate the kicking torque at the start of the four-wheel drive, the MG2 uses the high torque corresponding to the accelerator opening by MG2. By driving the rear wheels 80 and 82, the acceleration response is improved. In particular, in reverse, brake B1 during acceleration operation
Since the sliding engagement is performed, the feeling of backlash is prevented.

The power storage amount determination means 136 is provided for the power storage device 112.
Of charge (remaining charge) SOC of the battery
Value SOC_OIt is determined whether or not: This storage capacity judgment
Determination means 136 determines the state of charge SOC of power storage device 112.
Disconnection reference value SOC_OIf it is determined that
The electric power stored in the power storage device 112 during the traffic jam driving
Is supplied to the MG2, but the storage amount SO of the power storage device 112 is
C is the reference value SOC _OIf it is determined to be less
Is output from the MG 1 driven by the engine 14
Power is supplied to MG2.

The engine blow-up suppressing means 138 is switched from the non-power transmitting state to the power transmitting state by the engagement of the clutch C1 or C2, which is a hydraulic friction engagement device inserted in the front wheel power transmission path. In this case, for example, MG1 (generator) driven by engine 14
By temporarily increasing the electric load of the clutch C1 or in addition thereto, the throttle valve opening θ _TH is temporarily reduced by a predetermined amount to suppress the engine 14 from blowing up during the transition period of the engagement of the clutch C1 or C2. I do.

FIG. 6 shows the hybrid controller 104.
4 is a flowchart for explaining a main part of a control function such as a prime mover, that is, a motor switching control routine during traffic congestion. In step (hereinafter, step is omitted) SA1, it is determined whether or not the vehicle is traveling at a low speed equal to or less than a traffic congestion speed determination reference value V _X1 set in advance to, for example, 20 km / h or less. If the determination in SA1 is affirmative, in SA2,
It is determined whether the vehicle is traveling at a low opening degree where the throttle opening degree θ is equal to or less than a preset throttle opening degree determination reference value θ _X1 . If the determination in SA2 is affirmative, it is determined in SA3 whether the number N of times of starting and stopping per unit time is greater than a predetermined reference value _NX1 . Since SA1, SA2, and SA3 are used to determine the traffic congestion of the vehicle, they correspond to the traffic congestion determination means 128.

If any one of the determinations at SA1, SA2, and SA3 is negative, the normal traveling control mode is executed. However, if the determinations of SA1, SA2, and SA3 are both affirmative, the vehicle is in a traffic congestion state. Therefore, in SA4 corresponding to the storage amount determination unit 136, the remaining charge SOC of the power storage device 112 is determined in advance. It is determined whether or not it is smaller than the set reference value SOC _O. If the determination in SA4 is affirmative, in SA5 corresponding to the power transmission path release control means 130,
When the clutches C1 and C2 are released and the brake B1 is engaged, the front wheels 66, 68 are transmitted from the engine 14 via the planetary gear set 18 and the continuously variable transmission 20.
Up to the front wheel power transmission path is released, and the power transmission path is set to a non-power transmission state. At the same time, the motor switching control means 132
In SA6, the rear wheels 80 and 82 are driven by supplying electric energy output from the MG1 rotated and driven by the engine 14 to the MG2, and the vehicle is exclusively driven by the rear wheels 80 and 82.

Next, in SA7 corresponding to the acceleration operation determination means 134, it is determined whether or not the driver has performed an acceleration operation using the accelerator pedal 96, for example, by determining a predetermined reference value θ _X2 for the throttle opening θ. The determination is made based on whether the value has been exceeded or whether the value has become larger than the previous value. If the determination in SA7 is negative, the above-described SA4 and subsequent steps are repeatedly executed. If the determination is affirmative, the control corresponds to the power transmission path release control means 130, the prime mover switching control means 132, and the engine blow-up suppression means 138. In SA8, when the vehicle is moving forward, the clutch C1 and / or C2 is engaged to put the front wheel power transmission path in a power transmittable state, and at the same time, the ETC mode or the direct connection mode is selected according to the accelerator opening θ. Is done. In the case of reverse travel, the clutch C1 is engaged and the brake B1 is smoothly engaged, whereby the front wheel power transmission path is established and the power can be transmitted. Is selected. Thus, at least the front wheels 66 and 68 are driven by the engine 14. At the same time as or before the clutch C1 and / or C2 is engaged and the front wheel power transmission path is in a power transmittable state,
For example, the charge amount for power storage device 112 is maximized, and the electrical load of MG1 is temporarily increased,
Alternatively, in addition to this, the throttle actuator 21 temporarily reduces the throttle valve opening degree θ _TH by a predetermined amount, so that the engine 14 is suppressed from blowing up during the transition period of the engagement of the clutch C1 and / or C2.

At SA9, the front wheel power transmission path is
After the operation to switch to the power transmission enabled state is started
Elapsed time, i.e., clutch C1 and / or C2
Elapsed time t since engagement was commanded_ELBut the above clutch
A predetermined value corresponding to the engagement operation time of C1 and / or C2
Judgment reference time t₁It is determined whether it is smaller than. This
At first, the judgment of SA9 is affirmed, so
In SA10 corresponding to the exchange control means 132,
A8 of at least the front wheels 66, 68 by the engine 14
In addition to the driving, the driving of the rear wheels 80 and 82 by the MG2 is performed.
Large driving force corresponding to the amount of acceleration operation can be obtained.
The assist torque is output from the rear wheels 80 and 82
Thus, a four-wheel drive state is set. As a result, the engagement transition period
Discomfort that the driving force is not sufficiently transmitted into the vehicle, that is, acceleration
Good sloppy feeling when 4-wheel drive is started by operation
And an acceleration response can be obtained.
After SA10 is executed, SA9 and below are repeatedly executed.
However, if the determination in SA9 is denied,
In the normal traveling control mode, the elapsed time t _ELBut
Judgment reference time t₁Is exceeded, the engine 14
The front wheels 66 and 68 are driven.

If the determination at SA4 is negative, that is, if the power storage device 112 is not in the insufficient charge state, the clutches C1 and C2 are released at SA12 corresponding to the power transmission path release control means 130, and the SA5
The front wheel power transmission path is released in the same manner as described above. afterwards,
In SA13 corresponding to the prime mover switching control means 132, the power storage device 1 is stopped in a state where the engine 14 is stopped.
The electric energy stored in the vehicle 12 is supplied to the MG2, and the MG2 drives the rear wheels 80 and 82 to perform traffic congestion. Next, in SA14 corresponding to the congestion traveling determination means 128, it is determined whether or not the number N of start-stops per unit time is larger than a predetermined reference value N _X2 . However, N _X2 is set to a value corresponding to the SOC at the time of supply from the power storage device 112, because the lower the number N of start-stops, the sooner the storage amount SOC is expected to decrease to the specified value SOC _O. is there. If the determination in SA14 is affirmative, the use of power storage device 112 is restricted, so that by executing SA6 and below, MG1 is actuated by engine 14 and M1
MG2 based on the electric energy generated from G1
By driving the rear wheels 80 and 82, traffic congestion traveling is performed.

However, if the determination at SA14 is negative, SA1 corresponding to the acceleration operation determination means 134 is determined.
In 5, it is determined whether or not an acceleration operation has been performed in the same manner as in SA7. Initially, the determination at SA15 is denied, so that SA13 and subsequent steps are repeatedly executed. However, if the determination in SA15 is affirmative, S15 is performed as described above.
A8 and below are executed.

As described above, according to the present embodiment, when the congestion traveling determination means 128 (SA1, SA2, SA3) determines that the vehicle is traveling in congestion, the power transmission path release control means 130 (SA5, SA12). ) By engine 1
4 through the planetary gear unit 18 and the continuously variable transmission 20 to release the power transmission path from the front wheels 66 and 68 to the non-power transmission state.
(SA6, SA13) depending on the engine 14 or MG
1 to drive the rear wheels 80, 82 exclusively by the MG2, the engine 14 or the MG1 is separated from the front wheels 66, 68 and the rear wheel 8 exclusively driven directly by the MG2.
Since the front and rear wheel drive vehicles are driven by 0 and 82, high energy efficiency and fuel efficiency can be obtained during traffic jam driving. Since the front wheel power transmission path includes the planetary gear unit 18 and the continuously variable transmission 20 having mechanical power loss that lowers the transmission efficiency, the MG2 directly drives the rear wheels 80 and 82. However, the loss is small and the fuel efficiency is improved. At extremely low speeds, the MG2 can output a large output torque (drive torque).
When the MG2 is driven with a small output of 1, further lower fuel consumption is obtained.

According to the present embodiment, the acceleration operation determining means 1 determines whether or not the driver has performed an acceleration operation.
34 (SA7, SA15), and when the acceleration operation of the driver is determined by the acceleration operation determination means 134, the power transmission path release control means 130 (SA8) sets the front wheel power transmission path to non-power. together is switched from the transmission state to the power transmitting state, the prime mover switching control means 132 (SA8, SA10), in addition to the driving of the front wheels 66, 68 by at least the engine 14, by the MG2 to determine the reference time t ₁ has elapsed Rear wheel 80,
The assist drive of 82 is performed, and the four-wheel drive state is set.
That is, rear wheels 80 and 82 driven exclusively by MG2
When an acceleration operation is performed in a traffic congestion state, the front wheels 66 and 68 are driven by at least the ETC mode or the direct connection mode in which the engine 14 is operated, and the rear wheels 80 and 82 are assisted by the MG2. Therefore, a sufficient driving force can be obtained.

Further, according to the present embodiment, the motor switching control means 132 (SA8, SA10) is started by the power transmission path release control means 130 (SA8) to switch the front wheel power transmission path to the power transmission enabled state. until the elapsed time t _EL the elapses after a predetermined time t _1, when the front wheels 66, 68 is driven by the engine 14 at the same time MG2
, The rear wheels 80 and 82 are driven, and after the predetermined time t ₁ has elapsed, the front wheels 66 and 68 are driven exclusively by the MG1. Until the predetermined time t ₁ has elapsed, the MG
2, the assist torque is output. For this reason, when switching to a state in which power can be transmitted by engagement of the frictional engagement device inserted into the front wheel power transmission path, that is, the clutch C1 or C2, power is not sufficiently transmitted during the engagement transition period of the frictional engagement device. In this state, the assist torque is output from the rear wheels 80 and 82 by the MG2, so that a feeling of discomfort during the acceleration operation is eliminated and a good acceleration response is obtained.

Further, according to the present embodiment, during traffic congestion, electric power output from MG1 (generator) driven by engine 14 is supplied to MG2 and rear wheels 8
Since the vehicle is driven forward or backward by driving 0 and 82, there is an advantage that the vehicle can travel in congestion regardless of the capacity state of the power storage device 112 during congestion traveling.

Further, according to the present embodiment, during a traffic jam, if the state of charge SOC of power storage device 112 is sufficient, the power stored in power storage device 112 is supplied to MG2 and Power storage amount SO of power storage device 112
If C is insufficient, the electric power output from MG1 driven by engine 14 is supplied to MG2 to rotate rear wheels 80 and 82, and congestion is caused by the amount of power stored in the power storage device. There is an advantage that the vehicle can travel in congested traffic even when the state of charge SOC of the power storage device 112 becomes insufficient when traveling.

Further, according to the present embodiment, when the front wheel power transmission path is released by the power transmission path release control means 130 while the vehicle is being driven by the engine 14, for example, the amount of charge to the power storage device 112 By temporarily increasing the electric load of the MG 1 to the maximum, or additionally to the throttle actuator 2.
Since the engine blow-up suppressing means 138 for temporarily reducing the throttle valve opening θ _TH by a predetermined amount by 1 is provided, the blow-up of the engine 14 when the front wheel power transmission path is released is suitably suppressed. .

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 7 is a skeleton view for explaining the structure of the power transmission device of the four-wheel drive vehicle. The MG 1 is directly connected to the sun gear 24 to which torque is input from the engine 14. A clutch C3 is provided between the carrier 28 of the planetary gear unit 18 and the engine 14 instead of the clutches C1 and C2 provided between the input shaft 26 of the planetary gear unit 18 and the ring gear 32 and the carrier 28 of the planetary gear unit 18, respectively. Is different. In the present embodiment, when the clutch C3 and the brake B1 are both released, the power transmission path from the engine 14 to the front wheels 66 and 68 is released to be in a non-power transmission state. When one of them is engaged, power transmission is enabled. When the clutch C3 is engaged and the brake B1 is released, the elements constituting the planetary gear set 18 are integrally rotated, and the vehicle is in a forward state. When the brake B1 is engaged and the clutch C3 is released, the carrier 28 is rotated in the reverse direction with respect to the sun gear 24, so that the vehicle is brought into a reverse state. Therefore, the planetary gear device 18 of the present embodiment functions as a forward / reverse switching device.

FIG. 8 is a flowchart for explaining a main part of the control function of the hybrid control device 104 and the like, that is, a motor drive switching control routine at the time of traffic congestion in a vehicle provided with the above-described power transmission device. In the flowchart of FIG. 8, the clutch C3 and the brake B1 are released because the front wheel power transmission path is set to the non-power transmission state (SB5, SB1 corresponding to the power transmission path release control means 130).
2) One of the clutch C3 and the brake B1 is engaged because the front wheel power transmission path is in a state where power can be transmitted (S corresponding to the power transmission path release control means 130).
B8) is different from the embodiment of FIG. 6, but the other is the same. That is, the operation of SB1 to SB15 in FIG.
These correspond to SA1 to SA15 in FIG. 6, respectively.

In this embodiment, the same effects as those of the above embodiment can be obtained. For example, traffic congestion determination means 128
(SB1, SB2, SB3), if it is determined that the vehicle is running in congestion, the power transmission path release control means 130 (S
B5, SB12) release the power transmission path from the engine 14 to the front wheels 66, 68 via the planetary gear set 18 and the continuously variable transmission 20 to be in the non-power transmission state, and at the same time, the motor switching control means 132 (SB6, SB1
3) According to the engine 14 or the front wheel 6 by the MG1
Since the driving of the rear wheels 80 and 82 is exclusively switched by the MG2 from the driving of the engine 6 or 68,
G1 is cut off from front wheels 66 and 68 and M
Since the front and rear wheel drive vehicles are driven by the rear wheels 80 and 82 directly driven by G2, high energy efficiency and fuel efficiency can be obtained during traffic congestion.

Although the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the front and rear wheel drive vehicle of the above-described embodiment, the front wheels 66 and 68 are driven by the main drive unit 10 having the engine 14 and the MG1, and the rear wheels 80 and 82 are driven by the MG2.
The main drive unit 10 drives the rear wheels 80 and 82, and the front wheels 66 and 6
8 may be driven by the auxiliary drive device 12.

In the above-described embodiment, the congestion traveling determination means 128 determines that the number of stops and starts N per unit time is a predetermined value N _X1 during low load traveling at a prescribed throttle opening θ _X1 or less at a prescribed vehicle speed V _X1 or less. The congestion traveling of the vehicle is determined based on the above. For example, a position signal indicating the position of the vehicle output from a car navigation (vehicle traveling position detection display device) using a radio wave from an artificial satellite or a change thereof. The traffic jam may be determined based on Alternatively, the determination may be made in advance or locally based on traffic congestion information in the city.

In the above-described embodiment, the SA shown in FIG.
In 6, the power storage device 112 may be charged by using a part of the power output from the MG1, and may travel on the rear wheels 80 and 82 driven by the MG2 with another part of the power. .

Further, in the above-described embodiment, the SA shown in FIG.
In 14, it was determined whether the number N of stop times per unit time exceeded a predetermined criterion value N _X2 , but the total number N of stop times N _T after the determination in SA4 was denied is determined. Alternatively, it may be determined that a predetermined determination value indicating when charging of power storage device 112 is required is exceeded.

Further, in the above-described embodiment, SA15 in FIG.
If the determination is negative, SA13 and below are executed, but SA3 and SA4 and below may be executed.

Although the embodiment of the present invention has been described in detail with reference to the drawings, this is merely an embodiment,
The present invention can be implemented in various modified and improved aspects based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of a power transmission device of a four-wheel drive vehicle including a control device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a control device provided in the four-wheel drive vehicle of FIG.

FIG. 3 is a chart showing a control mode selected by the hybrid control device of FIG. 2;

FIG. 4 is an alignment chart illustrating an operation of the planetary gear device in the ETC mode controlled by the hybrid control device of FIG. 2;

FIG. 5 is a functional block diagram illustrating a main part of a control function of the hybrid control device and the like in FIG. 2;

FIG. 6 is a flowchart illustrating a main part of a control operation of the hybrid control device and the like in FIG. 2;

FIG. 7 is a skeleton diagram illustrating a configuration of a power transmission device for a four-wheel drive vehicle according to another embodiment of the present invention.

FIG. 8 is a flowchart illustrating a main part of a control operation of the embodiment of FIG. 7;

[Explanation of symbols]

 MG1: motor generator (first prime mover) MG2: rear motor generator (second prime mover) 14: engine (first prime mover) 20: continuously variable transmission 66, 68: front wheels 80, 82: rear wheels (wheels) 112: power storage Device 128: congestion traveling determination means 130: power transmission path release control means 132: prime mover switching control means 134: acceleration operation determination means 136: charged amount determination means

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) QE10 QE15 QE16 QI04 QI09 QN03 QN12 RB08 RB15 RE01 RE05 SE04 SE05 SE08 SE09 SJ12 SJ13 TB01 TE03 TI01 TO21 TO23

Claims (5)

[Claims] 1. A control apparatus for a front-wheel drive vehicle, comprising: a first prime mover capable of driving one of the front and rear wheels via a transmission; and a second prime mover capable of driving the other wheel. A congestion traveling determination unit that determines congestion traveling of the front and rear wheel drive vehicle; and when the congestion traveling determination unit determines that congestion traveling, the vehicle reaches one wheel from the first prime mover via the transmission. A power transmission path release control means for releasing a power transmission path to make a non-power transmission state; and, when traffic jam traveling is determined by the traffic jam traveling determination means, the driving of one of the wheels by the first prime mover causes the A drive motor switching control means for switching to driving of the other wheel by the two prime movers. 2. An acceleration operation determining means for determining whether or not an acceleration operation has been performed by a driver, wherein the power transmission path release control means performs an acceleration operation by the driver by the acceleration operation determination means. If it is determined that the power transmission path has been switched from the non-power transmission state to the power transmission enabled state, the prime mover switching control means determines that the driver has performed an acceleration operation by the acceleration operation determination means. 2. The control device for a front-rear wheel drive vehicle according to claim 1, wherein when the determination is made, both the front wheels and the rear wheels are driven by the first motor and the second motor. 3. The first motor and the first motor are connected to each other until a predetermined time elapses after the power transmission path is switched to the power transmission enabled state by the power transmission path release control means. 3. The control device for a front-wheel drive vehicle according to claim 2, wherein the front and rear wheels are driven by two prime movers, and after the predetermined time has elapsed, one of the wheels is driven by the first prime mover. 4. A generator driven by the first prime mover is provided, and the second prime mover is an electric motor. In the congested traveling, electric power output from the generator driven by the first prime mover is provided. The control device for a front-rear wheel drive vehicle according to claim 1, wherein the vehicle is driven by being supplied to the electric motor. 5. An electric storage device in which electric power is stored, and an electric storage amount determining means for judging whether or not an electric storage amount of the electric storage device is equal to or less than a predetermined reference value. When it is determined that the power storage amount of the power storage device is equal to or greater than the determination reference value, the power stored in the power storage device is supplied to the electric motor, and the power storage amount of the power storage device is greater than the determination reference value. The control device for a front-rear wheel drive vehicle according to claim 4, wherein when it is determined that the power is small, electric power output from a generator driven by the first prime mover is supplied to the electric motor.