JP2001112116A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the controller for a hybrid vehicle which does not impair the durability of a transmission belt. SOLUTION: When an engine 14 which is judged to be in a cool state by a cool state judging means 130 is started, an MG 16 is turned in a state that a ring gear is fixed with a brake B1 by a start control means 136 to start the engine 14 without using a starter motor 86. With the constitution, the slippage of a transmission belt 88 and the significant decline of the service life of the belt 88, which are caused by using the belt 88 in a hardened state, can be avoided surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hybrid vehicle, and more particularly to a technique for switching an internal combustion engine starting method.

[0002]

2. Description of the Related Art An internal combustion engine is connected to a first rotating element among three rotating elements of a sun gear and a ring gear of a planetary gear unit and a carrier which rotatably and revolvably supports a pinion which always meshes with the sun gear and the ring gear. Then, a motor generator is connected to the second rotating element, a transmission is connected to the third rotating element, and the connection state of the three rotating elements is switched, so that motor running, motor and engine running, start running, and regeneration 2. Description of the Related Art Hybrid vehicles that perform traveling and the like are known. For example, JP-A-9-17
That is the vehicle described in Japanese Patent No. 0533.

[0003]

The above-mentioned conventional hybrid vehicle is a two-motor type power transmission mechanism.
During motor running with a one-motor type power transmission mechanism, the internal combustion engine may not be able to be started, especially in a low-speed running state.

On the other hand, it is conceivable that a starter motor is operatively connected to the internal combustion engine via a transmission belt so that the internal combustion engine can be started even during low-speed running using only the motor. However, when the internal combustion engine is started exclusively by the starter motor, for example, when the internal combustion engine is started in a state where the transmission belt is hardened due to a low-temperature leaving state, the transmission belt slips. There is a problem that it is liable to occur and the life may be significantly shortened.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device for a hybrid vehicle which does not impair the durability of a power transmission belt.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an internal combustion engine operatively connected to a starter motor via a transmission belt, a motor generator, and the internal combustion engine. And control of a hybrid vehicle including a first rotating element and a second rotating element to which power of a motor generator is input, respectively, and a planetary gear unit that combines the power of the internal combustion engine and the motor generator and outputs the combined power from a third rotating element. A device,
(A) cold time determination means for determining whether it is cold,
(b) When starting the internal combustion engine determined to be in the cold state by the cold time determination means, starting the internal combustion engine by rotating the motor generator with the third rotating element fixed. And control means.

[0007]

With this configuration, when the internal combustion engine is determined to be in the cold state by the cold state determination means, the motor generator is started with the third rotating element fixed by the start control means. Since the internal combustion engine is started without using the power transmission belt by rotating, the inconvenience of starting the internal combustion engine by the starter motor is eliminated. That is, since the power transmission belt is not used in a hardened state, the risk of slippage of the power transmission belt and the possibility of significantly shortening the life of the power transmission belt is suitably prevented.

[0008]

Preferably, the start control means controls the starter motor to start the internal combustion engine by the starter motor when the internal combustion engine is determined not to be in the cold state by the cold state determination means. To start. With this configuration, when there is a request to start the internal combustion engine in a state where the engine is not cold, the internal combustion engine is started by the starter motor operatively connected to the internal combustion engine via the transmission belt. Therefore, since the internal combustion engine is normally started only by the starter motor during normal times, the control of the motor generator becomes simpler than when the internal combustion engine is started by the motor generator.

Preferably, the start control means interrupts power transmission between the first rotating element and the second rotating element and a driving wheel and fixes the third rotating element in a state where the third rotating element is fixed. The internal combustion engine is started by reversing the motor generator. With this configuration, when the vehicle is stopped, the internal combustion engine in a cold state can be suitably started.

Preferably, the hybrid vehicle further includes a start requesting means for issuing a request for starting the internal combustion engine in response to an operation of an ignition key at least in a cold state. With this configuration, the internal combustion engine is always started and warmed up at the start of operation, so that the internal combustion engine is started only by the start control means for the first time after being left for a long time.

Preferably, the control device further includes a warm-up judging means for judging whether or not the warm-up is performed based on the temperature of the cooling water of the internal combustion engine, and the warm-up judging means performs the warm-up. If it is determined that the internal combustion engine has not been started, the internal combustion engine is started. With this configuration, even if the ignition key is operated, the internal combustion engine is not started when the air is warmed up, so that unnecessary start of the internal combustion engine can be prevented.

Preferably, when the internal combustion engine is started during running in the motor running mode by the starting control means, a direct connection mode in which the three rotating elements of the planetary gear unit are integrally rotated. Causes the vehicle to run. With this configuration, the vehicle can be driven by the power of the internal combustion engine and also by the power of the internal combustion engine and the motor generator.

Preferably, the hybrid vehicle is a four-wheel drive vehicle in which the internal combustion engine and a motor generator drive one of a front wheel and a rear wheel, and the other motor generator drives the other wheel. When the internal combustion engine is started by rotating the motor generator by the start control means during running of the vehicle, the other wheel is driven by the other motor generator to drive. With this configuration, during a period in which one wheel cannot be driven by the motor generator to start the internal combustion engine, the vehicle is driven by the other wheel driven by the other motor generator. A temporary change in the driving force of the vehicle accompanying the start of the internal combustion engine is suppressed, and the occurrence of a shock in the vehicle is suppressed.

[0014] Preferably, the third rotating element is 2
The frictional engagement device is connected to the non-rotating member and the input shaft of the transmission via two friction engagement devices, respectively, and the control device exclusively drives the motor generator when the two friction engagement devices are released. A motor running mode determining means for determining whether or not a motor running mode for running the vehicle based on the force, wherein the start control means determines whether the motor running mode is determined to be the motor running mode by the motor running mode determining means. When the engine is started, the starter motor is operated to start the internal combustion engine. With this configuration, when there is a request to start the internal combustion engine in the motor running mode, the start control unit operates the starter motor to start the internal combustion engine. That is, the internal combustion engine is started while traveling in the motor traveling mode, and the vehicle can travel with the power of the internal combustion engine. In this motor traveling mode, while the second rotary element to which the power of the motor generator is input contributes to the driving of the vehicle, two frictions between the third rotary element and the input shaft and the non-rotary member of the transmission are provided. The engagement device is released and the third
Since the rotating element and the first rotating element to which the power of the internal combustion engine is input are in a free rotation state and the internal combustion engine is in an independent state separated from the power transmission system, the internal combustion engine is started using the starter motor. In this case, the output torque of the starter motor does not temporarily increase the driving force of the vehicle, and the problem that a shock occurs in the vehicle is solved.

Preferably, the control device starts the internal combustion engine by using the starter motor during traveling, and the starter motor generates power from the starter motor toward the internal combustion engine. It is operatively connected to the internal combustion engine via a one-way clutch that is engaged when transmitted, but released when power is transmitted from the internal combustion engine toward the starter motor. With this configuration, the drive system for rotating the internal combustion engine by the starter motor for starting the internal combustion engine is provided independently of the drive system of the vehicle by the interposition of the one-way clutch. The inconvenience of starting the internal combustion engine by the starter motor is eliminated. That is, the power from the starter motor to the internal combustion engine is transmitted, but the power from the internal combustion engine to the starter motor is not transmitted, so that the internal combustion engine can be started smoothly and independently during traveling. The output torque of the starter motor temporarily increases the driving force of the vehicle and suppresses the occurrence of a shock in the vehicle, and the starter motor and the transmission belt are not rotated during the operation of the internal combustion engine. Power loss due to rotation is eliminated.

[0016]

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

FIG. 1 is a skeleton view for explaining the structure of a power transmission device for a four-wheel drive vehicle, that is, a front-rear wheel drive vehicle to which the present invention is applied. In this front-rear wheel drive vehicle, the front wheel system is
One having a plurality of drive units of a type driven by a first drive unit having a prime mover, ie, a main drive unit 10, and driving a rear wheel system by a second drive unit having a second prime mover, ie, a sub drive unit 12. It is.

The main drive unit 10 includes an engine 14, which is an internal combustion engine operated by burning a mixture of air and fuel, and a motor generator (hereinafter, MG) that selectively functions as an electric motor and a generator.
16) and a double pinion type planetary gear set 18
And a continuously variable transmission 20 whose gear ratio is continuously changed. The engine 14 functions as a first prime mover, that is, a main prime mover. Engine 14
Is provided with a throttle actuator 21 that drives the throttle valve to change the opening degree θ _TH of the throttle valve that controls the amount of intake air in the intake pipe.

The planetary gear unit 18 is a combined distribution mechanism that mechanically combines or distributes forces, and includes three rotating elements that 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 an input shaft 26 of the continuously variable transmission 20 via a second clutch C2 and connected to a non-rotating member such as a housing 30 via a brake B1. It has. The carrier 28 includes a sun gear 24 and a ring gear 32.
A pair of intermeshing and intermeshing pinions (planetary gears) 34 and 36 rotatably support them. 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. In this embodiment, the sun gear 24 corresponds to a first rotating element, the carrier 28 corresponds to a second rotating element, and the ring gear 32 corresponds to a third rotating element.

The planetary gear set 18 and its carrier 28
Is controlled in the operating state of the engine 14, that is, the rotating 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 16, is gradually increased. 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, if the gear ratio ρ (the number of teeth of the sun gear 24 / the number of teeth of the ring gear 32) of the planetary gear device 18 is, for example, 0.5, which is a general value, the torque of the ring gear 32: the torque of the carrier 28: the sun gear 24 Torque = 1 / ρ: (1-ρ) / ρ:
From the relationship 1, the torque of the engine 14 is amplified to 1 / ρ times, for example, 2 times, and transmitted to the continuously variable transmission 20.
This is called a torque amplification mode.

The continuously variable transmission 20 includes an input shaft 26.
The output shaft 38 includes a pair of variable pulleys 40 and 42 each having a variable effective diameter, and an endless annular transmission belt 44 wound around the pair of variable pulleys 40 and 42. The pair of variable pulleys 40
And 42 are fixed to the input shaft 26 and the output shaft 38 such that fixed rotators 46 and 48 fixed to the input shaft 26 and the output shaft 38, respectively, and V-grooves are formed between the fixed rotators 46 and 48. A movable rotator 50 which is movable in the axial direction and is relatively non-rotatable about the axial center.
And 52, and the transmission ratio γ (= input shaft rotation speed / output shaft rotation speed) is changed by applying thrust to the movable rotating bodies 50 and 52 to change the engaging diameter, ie, the effective diameter of the variable pulleys 40 and 42. And a pair of hydraulic cylinders 54 and 56.

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 auxiliary drive device 12 includes a rear motor generator (hereinafter, referred to as RMG) 70 functioning as a second prime mover, that is, an auxiliary prime mover. The torque output from the RMG 70 is supplied to a reduction gear 72 and a differential gear 74. ,
And a pair of rear wheels 80 via a pair of axles 76, 78,
82.

A V-pulley 85 connected to the crankshaft of the engine 14 via a one-way clutch 84 and a V-pulley 87 fixed to the output shaft of a starter motor 86
A transmission belt 88 is wrapped therebetween, and the starter motor 86 also starts the engine 14. The one-way clutch 84 is engaged when transmitting power in the direction from the starter motor 86 to the engine 14, but is released when power in the direction from the engine 14 to the starter motor 86 is transmitted. is there. The V pulleys 85 and 87 are made of steel (steel plate) or synthetic resin, and the transmission belt 88 wound around them is made of synthetic rubber or steel rubber, reinforced with well-known steel wire, cloth, aramid fiber, or the like. It is made of synthetic resin. The surface of the transmission belt 88 on the pulleys 85 and 87 side, that is, the torque transmission surface is made of synthetic rubber or synthetic resin.

FIG. 2 is a diagram simply showing the configuration of a hydraulic control circuit for switching the planetary gear unit 18 of the main drive unit 10 to various operation modes. P, depending on the driver
A manual valve 92 mechanically connected to a shift lever 90 that is operated to each of the R, N, D, and B range positions uses a shuttle valve 93 and responds to the operation of the shift lever 90 in response to the operation of the shift lever 90. , B, and R ranges, the original pressure output from an oil pump (not shown) is supplied to a first pressure regulating valve 94 for regulating the engagement pressure of the first clutch C1, and the engagement pressure of the clutch C2 in the D range and the B range. The original pressure is supplied to the second pressure regulating valve 95 for regulating the pressure, and the N range, the P range,
Third for adjusting the engagement pressure of the brake B1 in the R range
The source pressure is supplied to the pressure regulating valve 96. The second pressure regulating valve 95 and the third pressure regulating valve 96 control the engagement pressure of the second clutch C2 and the brake B1 according to the output signal from the linear solenoid valve 97 driven by the hybrid control device 104, and the first pressure regulating valve 94 Controls the engagement pressure of the first clutch C1 according to the output signal from the electromagnetic on-off valve 98, which is a three-way valve that is duty-driven by the hybrid control device 104.

FIG. 3 is a diagram illustrating the configuration of a control device provided in the front and rear wheel drive vehicle according to 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 the traction control controls the engine 14 so that the front wheels 66 and 68 during slipping grip the road surface. The throttle actuator 21 is controlled in order to temporarily reduce the output of the throttle actuator.

The transmission control unit 102 determines the actual transmission ratio γ and transmission torque, that is, the engine speed, based on a relationship preset so that the tension of the transmission belt 44 of the continuously variable transmission 20 becomes a necessary and sufficient value. 14 and MG1
6. The pressure regulating valve for regulating the belt tension pressure is controlled based on the output torque of No. 6 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. from a pre-stored relationship, based on the actual vehicle speed V and engine load for example a throttle valve opening theta _TH or accelerator pedal operation amount a _CC determines a target gear ratio gamma _m, actual gear ratio gamma is the target gear ratio controlling the gear ratio of the continuously variable transmission 20 gamma to match the gamma _m.

Further, the engine control device 100 and the shift control device 102 operate, for example, the throttle actuator 21 and the fuel control so that the operating point of the engine 14 moves, for example, along the best fuel consumption operation line shown in FIG. The injection amount is controlled and the speed ratio γ of the continuously variable transmission 20 is changed. In addition, the hybrid control device 10
In response to a command from 4 to change the throttle actuator 21 and the speed ratio γ in order to change the output torque T _E or the rotational speed N _E of the engine 14, the engine 14
Move the operating point of.

The hybrid control device 104 controls a first MG for controlling a drive current supplied from the power storage device 112 including a battery or the like to the MG 16 or a power generation current output from the MG 16 to the power storage device 112. The control device 116 and the driving current supplied from the power storage device 112 to the RMG 70 or the driving current supplied to the RMG 70
MG control device 12 for controlling inverter 118 that controls the generated current output from power storage device 112 to power storage device 112
0, the operation position P _SH of the shift lever 90, the operation amount A _CC of the accelerator pedal 122, the vehicle speed V, and the power storage device 112.
For example, one of a plurality of operation modes shown in FIG. 5 is selected based on the state of charge SOC, and the operation amount A _CC of the accelerator pedal 122 and the operation amount B _F of the brake pedal 124 are selected. , MG16 or RM
A torque regenerative braking mode in which a braking force is generated by a torque required for power generation in G70 or an engine brake mode in which a braking force is generated by a rotational resistance torque of the engine 14 is selected.

When the shift lever 90 is operated to the B range or the D range, for example, when starting with relatively low load or traveling at a constant speed, the motor traveling mode is selected, the first clutch C1 is engaged, and the second clutch is engaged. When both C2 and brake B1 are released, only MG16
Drives the vehicle. 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 an ETC mode or a direct connection mode, which will be described later, and the MG 16 or the RMG 70 is driven while maintaining the running state, and the MG 16 or the RMG 70 is driven.
70 charges power storage device 112.

In addition, a relatively middle load traveling or a high load traveling
In the direct connection mode, the first clutch C1 and the
The two clutches C2 are engaged together and the brake B1 is
When released, the planetary gear set 18 rotates integrally
Allowed, exclusively by the engine 14 or its engine
14 and MG 16 drive the vehicle, or
When the vehicle is driven exclusively by the engine 14, the MG
The storage device 112 is charged by 16. This direct connection
In the mode, the rotation speed of the sun gear 24, that is, the engine rotation speed
N_E(Rpm) and the rotation speed of the carrier 28, ie, MG16
Rotation speed N_MG(Rpm) and the rotation speed of the ring gear 32, that is,
Rotation speed N of input shaft 26 of stepped transmission 20 _INWhat is (rpm)
Since they have the same value, three rotation speeds in a two-dimensional plane
Axis (vertical axis), that is, sun gear rotation speed axis S, ring gear rotation
Number of rotations R, carrier rotation axis C and gear ratio axis (horizontal axis)
In the alignment chart of FIG. 6 drawn from
It will be shown. Note that, in FIG.
The interval between gear rotation axis S and carrier rotation axis C corresponds to 1.
And the distance between the ring gear rotation speed R and the carrier rotation speed axis C.
Corresponds to the gear ratio ρ of the double pinion type planetary gear set 18
are doing.

For example, in starting acceleration traveling, ETC
Mode, that is, the torque amplification mode is selected, and in a state where the second clutch C2 is engaged and the first clutch C1 and the brake B1 are both released, the power generation amount (regeneration amount) of the MG16, that is, the reaction force (MG16 By gradually increasing the driving torque to rotate), the vehicle is smoothly started to zero while the engine 14 is maintained at the predetermined rotation speed. Thus, Engine 1
4 drives the vehicle and MG 16
Assuming that the torque of the engine 14 is 1 / ρ times, for example, ρ = 0.5, the torque is amplified twice and transmitted to the continuously variable transmission 20.
That is, when the rotation speed N _{MG of the MG} 16 is at the point A in FIG. 6 (a negative rotation speed, that is, a power generation state), the input shaft rotation speed N _IN of the continuously variable transmission 20 is zero, and the vehicle stops. However, as shown by the dashed line in FIG. 6, the power generation amount of the _MG 16 is increased and the rotational speed N _MG is changed to the positive side point B, so that the input of the continuously variable transmission 20 is changed. The shaft rotation speed N _IN is increased, and the vehicle is started.

When the shift lever 90 is operated to the N range or the P range, basically, the neutral mode 1 is set.
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 MG 16. When the shift lever 90 is operated to the R range, for example, in 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 driven backward by the MG 16 exclusively. However, for example, in the middle load or high load reverse running, the friction running mode is selected, the first clutch C1 is engaged and 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 MG 16 as the driving force for moving the vehicle backward.

The hybrid control device 104
When the vehicle starts or suddenly accelerates according to the driving force of the front wheels 66, 68, the RMG 70 is operated according to a predetermined driving force distribution ratio to temporarily increase the driving force of the vehicle, and the rear wheels 80, The RMG 70 is used by the RMG 70 in order to increase the starting capability of the vehicle during high-μ road assist control that generates driving force also from 82 and during start-up running on low-friction roads (low-μ roads) such as frozen roads and snow-covered roads. At the same time as driving the wheels 80 and 82, low μ road assist control is performed to reduce the driving force of the front wheels 66 and 68, for example, by lowering the speed ratio γ of the continuously variable transmission 20.

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 value SOC _D , the power storage control device 106
Power storage device 11 using electric energy generated by MG 70
2 is charged or stored, and if the stored amount SOC exceeds a preset upper limit value SOC _U , the MG
16 or charging with electric energy from the RMG 70 is prohibited. In addition, at the time of the power storage, an actual expected power value (= power consumption + charging power) _Pb is stored in power storage device 11.
If the power or electric energy, which is a function of the temperature T _B , exceeds the range between the limit value W _IN and the limit value W _OUT for taking out, the acceptance or removal is prohibited.

The brake control device 108 is, for example, TR
Execute C control, ABS control, VSC control, etc.
Stability of the vehicle during starting, braking, and turning
Hydraulic brakes for increased traction or traction
Key to each wheel 66, 68, 80, 82 via the control circuit.
Kicked wheel brake 66_WB, 68_WB, 80_WB, 8
2_WBControl. For example, in TRC control, each wheel
Based on the signal from the provided rotation sensor, the wheel speed
(Vehicle speed converted based on wheel rotation speed)
If right front wheel speed V_FR, Left front wheel speed V_FL, Right rear wheel
Wheel speed V_RR, Left rear wheel vehicle speed V_RL, Front wheel speed [= (V_FR
+ V_FL) / 2], rear wheel speed [= (V_RR+ V_RL) / 2],
And vehicle speed (V_FR, V_FL, V_RR, V_RLThe most of
(Slow speed) V, for example, while the main drive wheels
Which is the difference between the front wheel speed
Control speed is a preset control start determination reference value ΔV
₁Is exceeded, a slip judgment is made for the front wheels, and
Rate R_S[= (ΔV / V_F) × 100%] is preset
Target slip rate R_S1Throttle act to get inside
Heater 21, wheel brake 66_WB, 68_WBEtc.
To reduce the driving force of the front wheels 66, 68. Also, A
In the BS control, each wheel slips during braking operation.
Wheel so that the rate is within the predetermined target slip range.
Brake 66 _WB, 68_WB, 80_WB, 82_WBFront wheel
66, 68, maintain the braking force of the rear wheels 80, 82,
Increase directional stability. In the VSC control, the turning of the vehicle is performed.
During the round running, the steering angle from a steering angle sensor not shown,
Yaw rate from yaw rate sensor, from 2-axis G sensor
Oversteer tendency of the vehicle based on the front-back, left-right acceleration, etc.
Alternatively, the understeer tendency is determined and the oversteer or
Wheel brakes to reduce understeer
66_WB, 68_WB, 80_WB, 82_WBAny, and the slot
Controls the actuator 21.

FIG. 7 shows the hybrid control device 104.
FIG. 3 is a functional block diagram for explaining a main part of a control function such as the above. In FIG. 7, when the ignition key is turned on, engine water temperature determination
It is determined whether or not the cooling water temperature of No. 4 is equal to or lower than a predetermined value, that is, whether or not the engine 14 is warmed up. The predetermined value is, for example, a temperature of about 0 (° C.) at which the engine can be started. In the present embodiment, the engine coolant temperature determining means 126 corresponds to a warm-up determining means. The start request unit 128 generates a start request for the engine 14 when the engine water temperature determining unit 126 determines that the water temperature is equal to or lower than a predetermined value, that is, when the engine is not warmed up.

Further, when the engine start request is issued by the start requesting means 128, the cold time judging means 130 outputs the environmental temperature detected by the temperature sensor 132, for example, the oil temperature of the continuously variable transmission 20, Atmospheric temperature and engine 14
It is determined whether the surface temperature or the like is extremely low. Here, “extremely low temperature” refers to a temperature of, for example, about −40 to 0 (° C.) at which the synthetic rubber or synthetic resin forming the transmission belt 88 becomes hard. The temperature sensor 132 is disposed, for example, in the vicinity of the engine 14 or the MG 16, in the engine room of the vehicle, or in a lubricating oil passage of the continuously variable transmission 20. The temperature data is provided to the determination means 130.

Further, when the engine start request is issued, the long-term leaving determination means 134 determines whether or not the elapsed time from the ignition-off measured by a timer or the like is longer than a predetermined value. judge. The predetermined value is, for example, such a time that the transmission belt 88 that has been left in a stopped state at the extremely low temperature has a habit in the elliptical shape wound around the pulleys 85 and 87 and cannot rotate smoothly. For example, the length is about 10 minutes. Then, the start control means 136 controls the cold-time determination means 13.
Based on the determination result of 0 and the long-time leaving determination means 134, the MG 16 and the starter motor 86 are driven alternatively, and the engine 14 is started by either of them. That is, at the time of starting the engine 14 which is determined to be in the cold state by the cold state determining means 130, the start control means 136 holds the MG 16 with the ring gear 32 fixed.
, The engine 14 is started. In the figure, the one-way clutch 84 provided between the starter motor 86 and the engine 14 is omitted.

FIG. 8 shows the hybrid control device 104.
It is a flowchart for explaining the main part of the control operation of,
This shows an engine start means selection routine executed immediately after an ignition key (not shown) is turned on. That is, at the start of the routine, the vehicle is in a stopped state with the shift lever 90 in the P range and the engine 1
4, MG16 and RMG 70 are not driven. The clutches C1 and C2 and the brake B1 are all in the released state. When the ignition key is turned on, in step SA1 corresponding to the engine water temperature determining means 126, it is determined whether or not the engine water temperature is equal to or lower than the predetermined value. In a situation in which the engine 14 has been driven until immediately before, such as immediately after running of the vehicle (that is, the vehicle is warming up), this determination is denied, so the routine is immediately terminated. If the warm-up has been completed, the engine 1
When the ignition key is turned on, the engine 14 can be started immediately when the start request for the engine 4 is issued.
There is no need to start.

However, when the engine water temperature is equal to or lower than the predetermined value, the engine 14 needs to be warmed up in preparation for a start request, so that the determination in step SA1 is affirmed, and the routine proceeds to step SA2. Start request means 128
In step SA2 corresponding to the above, a request to start the engine 14 is generated in response to the operation of turning on the ignition key.

Subsequently, in step SA3 corresponding to the cold time determining means 130 and the long time leaving determining means 134, it is determined whether or not the temperature in the engine room or the like is extremely low, and the ignition key is determined. It is determined whether or not a long time has passed since the turning-off operation of. If the temperature is extremely low and the elapsed time is equal to or more than the above-described predetermined value, this determination is affirmed, and therefore, Step SA4
Proceed to. That is, under such conditions, the transmission belt 8
Since the starter 86 attempts to start the engine 14 due to the stiffness of the transmission belt 8, the transmission belt 88 is likely to slide and be damaged.

In step SA4 corresponding to the start control means 136, the engine start by the MG 16 is selected, and the brake B1 is engaged to fix the ring gear 32 and the MG 16 as shown in the lower part of FIG. Is reversed. As a result, the sun gear 24 of the planetary gear set 18 is rotated in the opposite direction (forward direction) to the carrier 28, so that the output shaft of the engine 14 connected to the sun gear 24 is rotated in the forward direction and the engine 14 is rotated. Is started. That is, when the vehicle is stopped, the cold engine 14 is easily started. Therefore, since the engine is not started by the starter motor 86 in a situation where the transmission belt 88 is slippery, damage due to the slip and a reduction in life are prevented. At this time, the starter motor 86 and the engine 1
One-way clutch 84 (OW
C) is not engaged.

However, if it is determined in step SA3 that the temperature is not extremely low or that the time elapsed since the ignition key was turned off is sufficiently short, the transmission belt 88 is unlikely to slip. Engine Start Step by Starter Motor 86 (Step S
Go to A5). In step SA5 corresponding to the start control means 136, the starter motor 86 is activated as shown in the upper part of FIG. 9, whereby the rotation is transmitted to the engine 14 via the one-way clutch 84,
The engine 14 is started. As described above, when starting the engine by turning on the ignition key, the start by the MG 16 and the start by the starter motor 86 are selectively used. However, the start of the engine by the MG 16 is performed only when the start by the starter motor 86 as described above is not preferable. , The control of the MG 16 is not so complicated. At this time, the clutch C
1, C2 and brake B1 are released,
Since the power transmission path between the sun gear 24 and the carrier 28 and the front wheels 66 and 68 is cut off, only the output shaft of the engine 14 is rotated by the starter motor 86, and the rotation is performed by the planetary gear device. There is no power loss due to transmission to other members via 18.

By the way, except when the ignition is turned on, that is, when the vehicle is running or when the vehicle is stopped in the ignition-on state, the vehicle is warmed up as required, so that the engine shown in FIG. The starting means selection routine does not apply. That is, since the engine 14 is constantly warmed up, the starter motor 86
You don't need to limit startup. FIG. 10 shows the hybrid control device 104 when the vehicle is running or the like.
FIG. 3 is a functional block diagram for explaining the control function of FIG. FIG.
In, the motor running mode determination means 138 determines whether or not the vehicle is in the motor running mode. Also,
The start request determining means 140 determines whether or not a request to start the stopped engine 14 has been made during the execution of the motor travel mode. The presence or absence of the start request is determined based on, for example, a sudden increase in the accelerator opening and the presence or absence of a charge request from the power storage control device 106 when the vehicle is in the D range. Then, the start control means 136 starts the starter motor 86 to start the engine 14 based on the judgments of the motor running mode judgment means 138 and the start request judgment means 140. Note that the engine 14 and the like are omitted in the figure.

FIG. 11 shows the hybrid control device 10.
4 is a flowchart illustrating a main part of the control operation of No. 4, and illustrates an engine start control routine that is executed intermittently when the shift lever 90 is in the D range or the R range, for example. In FIG. 11, in step SB1 corresponding to the motor running mode determining means 138, it is determined whether or not the motor running mode is set. If the engine 14 is being driven instead of the motor running mode, this determination is denied, and this routine is immediately terminated. On the other hand, during the execution of the motor running mode, the determination is affirmative, and the process proceeds to step SB2.

In step SB2 corresponding to the above-mentioned start request judgment means 140, it is judged whether or not an engine start request has been issued. If there is no start request, this determination is denied, and the engine start control routine is terminated. However, when there is a sudden depression of the accelerator pedal 122, that is, when there is a request for acceleration, or when the state of charge SOC of the power storage device 112 becomes insufficient, for example,
The start request determination is affirmed, and the routine proceeds to step SB3.

Then, in step SB3 corresponding to the start control means 136, the starter motor 86 is started to start the engine 14, and the present routine ends. That is, the engine 14 is started by the starter motor 86 in principle except when the ignition key is turned on. At this time, the starter motor 86 is connected to the one-way clutch 84 as shown in FIG.
Is not connected to the output shaft of the engine 14 via the motor 14 so that the power from the engine 14 to the starter motor 86 is not transmitted. Therefore, even during traveling, the engine 14 can be started smoothly independently. In addition, in the motor running mode, as described above, since the clutch C2 and the brake B1 are in the released state, the sun gear 2
4 is free to rotate without transmitting power to the input shaft 26 of the continuously variable transmission 20, so that the output torque of the starter motor 86 temporarily increases the driving force of the vehicle, which may cause a shock to the vehicle. Absent. After the engine 14 is started in this way, the mode is switched to, for example, the direct connection mode, and the vehicle is driven by the driving force of the engine 14 and the driving force of the MG 16.

As described above, according to the present embodiment, when the engine 14 is determined to be in the cold state by the cold state determining means 130 (step SA3), the start control means 136 (step SA4) starts. Since the engine 14 is started without using the starter motor 86 by rotating the MG 16 with the ring gear 32 fixed by the brake B1, the transmission belt caused by being used in a state where the transmission belt 88 is hardened is used. The sliding of the transmission belt 88 and the possibility of significantly shortening the life of the transmission belt 88 are suitably prevented.

In this embodiment, when the engine is started in a state where the engine is not cold, the start control means 136 (step SA5) transmits the power transmission belt 88 to the engine 14.
By a starter motor 86 operatively connected via For this reason, the starter motor 86
The engine 14 is started by the
6 compared to the case where the engine 14 is started in
Control of G16 is simplified.

In the present embodiment, when the vehicle is cold, only the brake B1 is engaged, that is, the clutches C1 and C2 are released and the sun gear 24 is released.
MG1 with power transmission between carrier 28 and front wheels 66, 68 cut off and ring gear 32 fixed.
By reversing 6, the engine 14 is started. Therefore, when the vehicle is stopped, the cold engine 14 is suitably started.

In this embodiment, the engine start request is issued by the start request means 128 (step SA2) in response to the operation of the ignition key (ON operation) in the cold state. Is started and warmed up.
The starting of the engine 14 in 36 (step SA4 or step SA5) is performed exclusively in the first time after being left for a long time.

In this embodiment, the engine 14
Engine water temperature judging means 126 (step SA) for judging whether or not the warming-up is performed based on the cooling water temperature
1) is provided, and the engine 14 is started when the engine water temperature determining means 126 determines that the water temperature is equal to or lower than a predetermined value, that is, that the engine is not warmed up. For this reason, even if the ignition key is operated, the engine 14 cannot be started in the case of warm air, so that unnecessary starting can be prevented.

In the present embodiment, while the motor drive mode determining means 138 (step SB1) determines that the vehicle is in the motor drive mode, the start request determining means 140 (step SB2) requests the engine 14 to start. If it is determined that there is a
36 (step SB3), the starter motor 86 is operated and the engine 14 is started.
While the carrier 28 to which the power of the vehicle 16 is input is made to contribute to driving the vehicle, the ring gear 32 and the continuously variable transmission 20 are used.
The two frictional engagement devices clutch C2 and brake B1 between the input shaft 26 and the housing 30 are released, and the ring gear 32 and the sun gear 24 to which the power of the engine 14 is input are freely rotated, and the engine 14 Since the power transmission system is separated from the power transmission system, when the engine is started using the starter motor 86, the output torque of the starter motor 86 does not temporarily increase the driving force of the vehicle. The problem that a shock occurs is eliminated.

In this embodiment, the engine 14
The drive system for rotating the engine 14 by the starter motor 86 for starting the vehicle is provided independently of the drive system of the vehicle by the interposition of the one-way clutch 84. Therefore, when the engine 14 is started by the starter motor 86, the power from the starter motor 86 to the engine 14 is transmitted,
On the contrary, since the power from the engine 14 to the starter motor 86 is not transmitted, the engine 1
4 can be started smoothly in an independent state, so that the output torque of the starter motor 86 temporarily suppresses the increase in the driving force of the vehicle and the occurrence of a shock in the vehicle, and the operation of the engine 14 In some cases, the starter motor 86 and the transmission belt 88 are not driven to rotate, so that power loss due to their rotation is eliminated.

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 vehicle of the above-described embodiment, front wheels 66 and 68 are driven by main drive unit 10 having engine 14 and MG 16, and rear wheels 80 and 82 are driven by sub-drive unit 12 having RMG 70. It was a form, but rear wheel 8
0, 82 may be driven by the main drive device 10 and the front wheels 66, 68 may be driven by the sub drive device 12.

The vehicle of the above-described embodiment has the engine 1
The output energy of the engine 14 is converted into electric energy by the MG 16 and the RMG 70 that drives the rear wheels 80 and 82 is operated by the electric energy. However, the output energy of the engine 14 is converted into hydraulic energy by the hydraulic pump, and The vehicle in which the hydraulic motor driving the wheels 80 and 82 is operated by the hydraulic energy may be used.

In the vehicle of the embodiment, the front wheels 66, 68
And the rear wheels 80, 82 can both function as drive wheels 4
Although the case where the present invention is applied to a wheel drive vehicle has been described, main drive device 1 having engine 14 and MG 16
The invention can likewise be applied to a two-wheel drive vehicle with only zeros.

Further, in the embodiment, the engine 14 is exclusively used by the starter motor 86 while the vehicle is running.
, The change in the driving force accompanying the start and the shock of the vehicle have been suppressed, but the engine 14 may be started by the MG 16 even while the vehicle is running. In such a case, for example, the clutches C1, C
2 is released and the brake B1 is engaged.
If the driving force is compensated for, the change in the driving force and the shock of the vehicle can be prevented. Alternatively, while the vehicle is running, the clutches C1 and C2 are engaged and the brake B1 is released to transmit the rotation of the front wheels 66 and 68 to the engine 14 to start the engine by so-called pushing. You may.

In the embodiment, the starter motor 86 is connected to the engine 14 via the one-way clutch 84, but instead of providing the one-way clutch 84,
When the engine 14 is started, a gear provided on the output shaft of the starter motor 86 may be temporarily engaged with a gear provided on the output shaft thereof.

In the embodiment, the start of the engine by the starter motor 86 is prohibited when the engine is cold or left for a long time. However, the start by the starter motor 86 may be prohibited when the engine is cold or left for a long time. . That is, in step SA3 of the flowchart shown in FIG. 8, it is determined whether or not "start after cryogenic temperature or after leaving for a long time", and it is determined that the temperature is cryogenic. If it is determined (yes) that the elapsed time is sufficiently long, the process proceeds to step SA4 to perform MG16.
To start the engine 14 and proceed to step SA5 to start the engine 14 with the starter motor 86 only when both are denied.

Further, in the embodiment, the control routine shown in FIG. 8 is executed in response to the operation of the ignition key. However, the control routine can be executed periodically with the ignition key turned on. .

In the embodiment, the continuously variable transmission 20 is provided between the engine 14 and the MG 16 and the front wheels 66 and 68.
Is provided, but a stepped transmission may be provided instead.

Although the embodiments of the present invention have 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 main part of a hydraulic control circuit that controls the planetary gear device of FIG. 1;

FIG. 3 is a diagram illustrating a control device provided in the four-wheel drive vehicle of FIG.

FIG. 4 is a best fuel consumption operation line illustrating a control operation of the engine control device and the shift control device.

FIG. 5 is a chart showing a control mode selected by the hybrid control device of FIG. 3;

FIG. 6 is an alignment chart for explaining the rotation speed of each element of the planetary gear device.

FIG. 7 is a functional block diagram illustrating a main part of a control function of the hybrid control device and the like in FIG. 3;

8 is an example of an engine start routine performed by the hybrid control device shown in FIG.

FIG. 9 shows a friction engagement element and M in the control routine of FIG. 8;
It is a chart which shows the operation state of G etc.

10 is a functional block diagram illustrating an engine start control function during traveling by the hybrid control device of FIG. 3;

FIG. 11 is an example of an engine start control routine during traveling by the hybrid control device of FIG. 3;

[Explanation of symbols]

 14: Engine (internal combustion engine) 16: Motor generator 18: Planetary gear device 24: Sun gear (first rotating element) 28: Carrier (second rotating element) 32: Ring gear (third rotating element) 86: Starter motor 88: Transmission Belt 130: Cold-time determination means 136: Start control means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // F16H 59:78 B60K 9/00 E (72) Inventor Hidehiro Ohba 1st Toyota Town, Toyota City, Aichi Prefecture Toyota F-term (Reference) in Automobile Co., Ltd. LA01 5H115 PA15 PG04 PI16 PI29 PU01 PU22 PU25 QE01 QE15 QE16 QH02 QI04 QI09 QN03 QN06 RB08 RB15 RE01 RE05 RE13 SE04 SE05 SE08 SJ12 SJ13 TB01 TE08 TI01 TO05 TO21 TO23

Claims (2)

[Claims] An internal combustion engine operatively connected to a starter motor via a transmission belt; a motor generator;
The first rotating element and the second rotating element to which the powers of the internal combustion engine and the motor generator are respectively input and the powers of the internal combustion engine and the motor generator are combined to form a third rotary element.
A control device for a hybrid vehicle, comprising: a planetary gear device that outputs from a rotating element; a cold-time determining means for determining whether or not the vehicle is in a cold state; And starting control means for starting the internal combustion engine by rotating the motor generator with the third rotating element fixed when starting the internal combustion engine determined to be present. Control device. 2. The start control unit according to claim 1, wherein the start control unit starts the internal combustion engine by the starter motor when the internal combustion engine is determined not to be in the cold state by the cold state determination unit. Control device for hybrid vehicle.