JPH1075502A - Controller of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain an engine in an drivable state as much as possible in a hybrid vehicle which has the engine and an electric motor as power sources for the running of the vehicle, a low voltage 1st power accumulation device which supplies powers to auxiliary machines for the engine driving, a high voltage 2nd power accumulation device which supplies a power to the electric motor and, further, a voltage conversion controller which permits the 2nd power accumulation device to charge the 1st power accumulation device. SOLUTION: If it is judged that the charge value SOC2 β a 2nd power accumulation device is smaller than a required value f3 which corresponds to a sufficient power to drive an engine in a step SA3, charging of a 1st power accumulation device by the 2nd power accumulation device is prohibited. With this constitution, even if the power of the 1st power accumulation device is consumed by the lighting of headlights, etc., the engine can be driven by supplying a power from the 2nd power accumulation device at the time of the engine start.

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 first power storage device for supplying power to an engine driving accessory and a second power storage device for supplying power to an electric motor. is there.

[0002]

2. Description of the Related Art A hybrid vehicle having an engine that operates by burning fuel and an electric motor that operates by electric energy as a power source when the vehicle runs is described in, for example, Japanese Patent Application Laid-Open No. 7-67208. I have. In such a hybrid vehicle, a low-voltage (for example, 12 V) first power storage device for supplying power to a starter for starting an engine and a high-voltage (for example, 288 V) second power storage device for supplying power to an electric motor are provided. However, if the amount of power stored in the first power storage device decreases,
By charging the first power storage device from the power storage device, the engine can be kept drivable.

[0003]

However, in such a hybrid vehicle, if charging from the second power storage device to the first power storage device is allowed without limitation, for example, the first power storage device may be connected to various types of air conditioners and headlights. When used also as a power source for an in-vehicle device, the power of the first power storage device and further the power of the second power storage device are consumed unlimitedly by turning on a headlight or the like, and there is a possibility that the engine cannot be driven.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hybrid vehicle having an engine and an electric motor as power sources for running the vehicle. As long as the engine can be driven.

[0005]

In order to achieve the above object, the present invention provides (a) an engine operated by fuel combustion and an electric motor operated by electric energy as a power source for driving a vehicle. And (b) a first power storage device that supplies power to the auxiliary equipment for driving the engine, and a second power storage device that supplies power to the electric motor, and (c) a second power storage device that supplies power to the electric motor. In a control device for a hybrid vehicle having a charging unit for charging the first power storage device,
(d) Charging from the second power storage device to the first power storage device is changed according to the amount of power stored in the second power storage device.

[0006]

According to the present invention, from the second power storage device to the first power storage device,
Since charging of the power storage device is changed in accordance with the amount of power stored in the second power storage device, for example, the amount of power stored in the second power storage device is equal to or less than a predetermined value having a sufficient amount of power required to drive the engine. In this case, if the charging is not performed, the engine can be driven by supplying power from the second power storage device when the engine is started, even if the power of the first power storage device is consumed by turning on the headlights or the like. Becomes possible.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a switching type in which a power source is switched by connecting and disconnecting power transmission by, for example, a clutch means, and an output of an engine and an electric motor by a composite distribution mechanism such as a planetary gear device. Such as a mix type that synthesizes and distributes the power, an electric motor or an assist type that uses the engine as an auxiliary, and can be applied to various types of hybrid vehicles including an engine and an electric motor as power sources during vehicle running. .

[0008] In addition to the starters required for starting the engine, igniters, distributors, injectors, and the like include auxiliary equipment for driving the engine.
Various components necessary for maintaining the driving state of the engine such as an EFI computer are also included.

A voltage converter, such as a chopper circuit, is provided between the first power storage device and the second power storage device. According to this voltage converter,
Of course, charging from the first power storage device to the second power storage device is also possible.

In the case where the charging from the second power storage device to the first power storage device is changed in accordance with the power storage amount of the second power storage device, the change is performed by setting the power storage amount of the second power storage device to a predetermined value. Various modes are included such as completely prohibiting charging when the value becomes equal to or less than the value, and gradually reducing the charged amount according to the charged amount of the second power storage device.

The first power storage device is a low-voltage power supply such as 12 V, for example.
The present invention is suitably applied to a case where it is also used as a power source for various in-vehicle devices such as an air conditioner and a headlight.

In addition, when there is a request for starting the engine, such as when the start switch is turned on, it is desirable that the first power storage device be charged by the charging means so that the engine can be started. Instead of charging the first power storage device, the engine may be started by supplying power directly to auxiliary equipment such as a starter. The request to start the engine may be made by a computer or the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a skeleton diagram of a hybrid drive device 10 of a hybrid vehicle including a control device according to one embodiment of the present invention.

In FIG. 1, a hybrid drive unit 10 is for a front-engine / rear-drive (FR) vehicle, and functions as an engine 12 such as an internal combustion engine that operates by burning fuel, and functions as an electric motor and a generator. A motor generator 14, a single-pinion type planetary gear set 16, and an automatic transmission 18 are provided along the front-rear direction of the vehicle, and are driven right and left from an output shaft 19 via a propeller shaft (not shown) and a differential unit. The driving force is transmitted to the driving wheels (rear wheels).

The planetary gear unit 16 is a composite distribution mechanism for mechanically distributing and distributing force. The planetary gear unit 16 constitutes an electric torque converter 24 together with the motor generator 14, and its ring gear 16.
r is connected to the engine 12 via the first clutch CE _1, sun gear 16s is connected to the rotor shaft 14r of the motor generator 14, the carrier 16c automatic transmission 18
Are connected to the input shaft 26. Sun gear 16s
And carrier 16c is adapted to be connected by the second clutch CE _2.

[0016] The output of the engine 12 is transmitted rotation fluctuation and the flywheel 28 and the spring for suppressing the torque variation, the first clutch CE ₁ via a damper device 30 by the elastic member such as rubber. Each of the first clutch CE ₁ and the second clutch CE ₂ is a friction type multi-plate clutch that is engaged and released by a hydraulic actuator.

The automatic transmission 18 is a combination of an auxiliary transmission 20 composed of a front type overdrive planetary gear unit and a main transmission 22 having four forward stages and one reverse stage composed of a simple connection of three planetary gear trains. .

More specifically, the auxiliary transmission 20 is a single pini
ON type planetary gear set 32 and hydraulic actuator
Hydraulic clutch C frictionally engaged₀ , Bray
Key B ₀ And one-way clutch F₀ And is configured with
You. The main transmission 22 has three sets of single pinion type.
Planetary gear units 34, 36, 38, and hydraulic actuator
Hydraulic clutch C frictionally engaged by₁ ,
C_Two , Brake B₁ , B_Two , B_Three , B_Four And a one-way club
Switch F₁ , F_Two It is comprised including. And this
These clutches C₀~ C_Two, Brake B₀~ B_FourPerson in charge
In this case, as shown in FIG.
One shift stage is established. The above automatic transmission
18 and the electric torque converter 24 are substantially symmetrical with respect to the center line.
In FIG. 1, the lower half of the center line is omitted.
ing.

FIG. 2 is a block diagram for explaining a control system of the hybrid drive device 10. The mechanical connection is shown by a thick solid line, and the electrical connection is shown by a thin line.

In FIG. 2, the electric torque converter 24 comprises the motor generator 14, the planetary gear set 16, the first clutch CE ₁ and the second clutch CE ₂ , and the vehicle driving means 44 is a driving wheel or the like. .

The engine 12 is controlled by the hybrid control controller 40 to operate the fuel injection control actuator 4.
6. The operation state of the throttle control actuator 48, the ignition timing control actuator 50, and the intake / exhaust valve control actuator 52 is controlled by being controlled.

The motor generator 14 is connected to a high-voltage second power storage device 56 via a motor generator control device (such as an inverter) 54, and the motor generator control device 54 The electric power is supplied from the second power storage device 56 and the motor is rotated by a predetermined torque, and a regenerative braking (electric braking torque of the motor generator 14 itself) as a generator. The state is switched between a functioning charging state and a no-load state that allows the rotor shaft 14r to freely rotate.

The first clutch CE ₁ and the second clutch CE ₂ are engaged and disengaged by the hybrid controller 40 switching the hydraulic circuit via a clutch control actuator 58 such as an electromagnetic valve. Is switched, and the connection between the engine 12 and the ring gear 16r and the connection between the sun gear 16s and the carrier 16c are respectively connected and disconnected.

The voltage conversion control device 62 is, for example, a chopper circuit, and the hybrid control controller 4
Under the control of 0, the discharge output of the second power storage device 56 is converted to a lower voltage and supplied to the first power storage device 64 side, or the discharge output of the first power storage device 64 is converted to a higher voltage. To the second power storage device 56 side. First power storage device 64
Is provided with an external charging terminal 65 at the same voltage as a power storage device of an engine-driven vehicle that is widely used at present, for example, 12 V. The second power storage device 56 is a high-voltage, for example, 288 V, power storage device for driving the vehicle. Note that the voltage conversion control device 62 corresponds to the charging means.

The accessory control device 66 is connected to the first power storage device 64 and the voltage conversion control device 62 via the changeover switch 55, and the changeover switch 55 controls the hybrid control controller 40. Below, a first connection state in which the accessory control device 66 and the first power storage device 64 are connected, and a second connection state in which the accessory control device 66 and the voltage conversion control device 62 are connected are switched. . In the first connection state, when power is supplied from the first power storage device 64 to the auxiliary devices 67 via the auxiliary device control device 66, the auxiliary devices 67 are drive-controlled. Also, the second
In the connected state, the electric power from the second power storage device 56 converted to a low voltage by the voltage conversion control device 62 is directly supplied to the auxiliary devices 67 via the auxiliary device control device 66,
The driving of the accessories 67 is controlled.

The auxiliary devices 67 include various components such as a starter necessary for starting the engine 12, an igniter, a distributor, an injector, an EFI computer and the like necessary for maintaining a driving state of the engine 12, and an air conditioner and the like. It is composed of various in-vehicle devices such as headlights. The fuel injection control actuator 46, the throttle control actuator 48, the ignition timing control actuator 50, the intake / exhaust valve control actuator 5
2 and the like are also included in the auxiliary devices 67 and are supplied with power from the first power storage device 64.

In the automatic transmission 18, the shift lever 60 is operated by the driver, and the hydraulic circuit is switched by a switching actuator 68 such as a manual shift valve mechanically connected to the shift lever 60, so that the forward gear ( FWD), neutral (N), and reverse (REV) are switched. The shift lever 60 is
"P (parking)", "R (reverse)", "N (neutral)", "D (drive)", "4",
A total of eight shift ranges of “3”, “2”, and “L” are provided, and the reverse gear is established in the “R” range.
The neutral is established in the “N” range, and the forward gear is established in the “D” range.

Further, it like is supplied from a shift position signal shift position switch 70 that represents the S _H to the hybrid control controller 40, the "D" range, the transmission ratio control actuator 72 is controlled such shifting solenoid valve And the hydraulic circuits are switched, whereby the clutches C ₀ -C ₂ and the brakes B ₀ -B
₄ engagement, is switched is released state is switched shift speed forward fifth speed, for example, according to a shift condition such as a predetermined shift map accelerator displacement theta _AC and the vehicle speed V as parameters.

In the clutch, brake, and one-way clutch columns of FIG. 3, "O" indicates engagement, and "●" indicates that the shift lever 60 is in the engine brake range, for example, "3", "2", and "L" ranges. Engaged when operated to the low speed range of
A blank indicates non-engagement.

The gear ratio of the forward gear is 5 from 1st.
and the speed ratio i _{4 of the} 4th is 1 and the speed ratio i ₅ of the _5th is smaller than the auxiliary transmission 2
Assuming that the gear ratio of the planetary gear device 32 of 0 is ρ (= the number of teeth of the sun gear Z _S / the number of teeth of the ring gear Z _R <1), 1 / (1+
ρ). FIG. 3 shows an example of the gear ratio of each gear.

As shown in the operation table of FIG.
Shifting between the gear stage (2nd) and third shift stage (3rd) will clutch-changing the engagement-released state of the second brake B ₂ and the third brake B ₃ together.
In order to smoothly perform this shift, the circuit shown in FIG. 4 is incorporated in the above-described hydraulic circuit.

In FIG. 4, reference numeral 90 indicates a 1-2 shift valve, and reference numeral 91 indicates a 2-3 shift valve.
Reference numeral 92 indicates a 3-4 shift valve. The communication state of each port of these shift valves 90, 91, 92 at each shift speed is determined by the respective shift valves 90, 9
1 and 92 are shown below. The numbers indicate the respective gears.

The third brake B ₃ is connected to an oil passage 9 at a brake port 94 communicating with the input port 93 at the first and second shift speeds among the ports of the 2-3 shift valve 91.
5 are connected. This oil passage has an orifice 9
6 is interposed, the damper valve 97 is connected between the orifice 96 and the third brake B _3.
The damper valve 97 is configured to perform a buffering action by inhalation of a small amount of hydraulic pressure when the line pressure to the third brake B ₃ is rapidly supplied.

Further numeral 98 is a B-3 control valve has a third engaging pressure of the brake B ₃ to be directly controlled by the B-3 control valve 98. That is, the B-3 control valve 98
Is provided with a spool 99, a plunger 100 and a spring 101 interposed therebetween.
Oil passage 95 to the input port 102 to be opened and closed is connected, and the output port 103 to be brought selectively communicating with the input port 102 is connected to the third brake B ₃ by. Further, the output port 103 is connected to a feedback port 104 formed on the leading end side of the spool 99.

On the other hand, a 2-3 shift valve 9 is provided at a port 105 opening at a position where the spring 101 is disposed.
The port 106 of the one port, which outputs the D range pressure at the third speed or higher, is communicated via the oil passage 107. The control port 108 formed on the end side of the plunger 100 has a linear solenoid valve SL.
U is connected.

Therefore, the B-3 control valve 9
Reference numeral 8 denotes a pressure adjusting level set by the elastic force of the spring 101 and the hydraulic pressure supplied to the port 105, and the elastic force of the spring 101 increases as the signal pressure supplied to the control port 108 increases. ing.

Further, reference numeral 109 in FIG.
The 2-3 timing valve 109 includes a spool 110 and a first plunger 111 having a small-diameter land and two large-diameter lands, a spring 112 and a spool 110 disposed therebetween.
And a second plunger 113 disposed on the opposite side of the first plunger 111 with respect to the first plunger 111.

An oil passage 115 is connected to a port 114 at an intermediate portion of the 2-3 timing valve 109. The oil passage 115 is connected to a port of the 2-3 shift valve 91 at a speed higher than the third speed. It is connected to a port 116 that communicates with the brake port 94.

Further, the oil passage 115 branches in the middle and is connected via an orifice to a port 117 opened between the small land and the large land. Port 1 selectively connected to port 114 of the intermediate portion
Reference numeral 18 denotes a solenoid relay valve 12 via an oil passage 119.
Connected to 0.

[0040] Then, the linear solenoid valve SLU is connected to the port that is open to an end portion of the first plunger 111 and the second brake B ₂ is an orifice to a port that opens to the end of the second plunger 113 Connected through.

[0041] The oil passage 107 is for the purpose of supplying and discharging the hydraulic pressure to the second brake B _2, a small diameter orifice 121 and a check ball with the orifice 122 is interposed in the midway. Also, this oil passage 107
An oil passage 123 branched from the large-diameter orifice 124 having a check ball to open when the pressure discharged from the second brake B ₂ is interposed, the oil passage 123 is connected to the orifice control valve 125 to be described below ing.

The orifice control valve 125 is a valve for controlling the speed of exhausting the pressure from the second brake B _2. The orifice control valve 125 has a port 127 formed at an intermediate portion so as to be opened and closed by a spool 126. _Two
The oil passage 123 is connected to a port 128 formed below the port 127 in the figure.

Port 1 to which the second brake B ₂ is connected
The port 129 formed on the upper side of FIG. 27 is a port selectively connected to the drain port. The port 129 is connected to the port 131 of the B-3 control valve 98 via an oil passage 130. It is connected. Incidentally, this port 131 is a port that is not selectively communicating the output port 103 which is connected to the third brake B _3.

A control port 132 formed at an end of the port of the orifice control valve 125 opposite to the spring for pressing the spool 126 is connected to a port 134 of the 3-4 shift valve 92 via an oil passage 133. ing. This port 134 outputs the signal pressure of the third solenoid valve SL3 at a speed lower than the third speed,
Further, it is a port for outputting a signal pressure of the fourth solenoid valve SL4 at a speed higher than the fourth speed. These solenoid valves SL3 and SL4 are components of the gear ratio control actuator 72.

The orifice control valve 125 has an oil passage 135 branched from the oil passage 115.
Are connected, and the oil passage 135 is selectively communicated with the drain port.

In the 2-3 shift valve 91, a port 136 for outputting the D-range pressure at a speed lower than the second speed is opened at a portion of the 2-3 timing valve 109 where a spring 112 is disposed. Port 13
7 through an oil passage 138. Also, 3-4
A port 139 of the shift valve 92 which is communicated with the oil passage 107 at a speed lower than the third speed is connected to an oil passage 140.
Is connected to the solenoid relay valve 120 via the.

In FIG. 4, reference numeral 141 denotes the second
Indicates an accumulator for the brake B _2, accumulator control pressure linear solenoid valve SLN is pressure regulated in accordance with the hydraulic pressure output is supplied to the back pressure chamber. The accumulator control pressure is configured to increase as the output pressure of the linear solenoid valve SLN decreases. Thus, transient oil pressure of the second brake B ₂ engagement and release, the signal pressure of the linear solenoid valve SLN is adapted to remain at lower higher pressures.

[0048] Further, reference numeral 142 denotes a C-0 exhaust valve, further numerals 143 denotes an accumulator for the clutch C _0. C-0 exhaust valve 1
42 is to operate to engage the clutch C ₀ in order to engine brake only at the second gear of the second speed range.

Therefore, according to the hydraulic circuit described above,
If communicating port 131 to the drain of the B-3 control valve 98, the third engaging pressure of the brake B ₃ B-
The pressure can be directly adjusted by the three control valve 98, and the pressure adjustment level can be changed by the linear solenoid valve SLU.

The orifice control valve 12
5 is in the position shown in the left half of the figure, the second brake B ₂ is able to relieve pressure through this orifice control valve 125,
It is possible to control the drain rate from the brake B _2.

Further, when shifting from the second gear to the third gear, the third brake B ₃ is gradually released and the second gear is released.
But not so-called clutch-to-clutch shifting gently engage the brake B ₂ is carried out, in advance estimating the input torque to the input shaft 26 prior to the shifting, the linear solenoid valve on the basis of the input torque estimation value the third shift shock by controlling the disengagement transition pressure of the brake B ₃ driven by SLU can be suitably reduced.

The hybrid control controller 40 includes:
The microcomputer includes a microcomputer having a CPU, a RAM, a ROM, and the like. As shown in FIG. 2, a shift position switch 70, an accelerator operation amount sensor 74, a brake switch 76, a brake depression force sensor 78, a start switch 82, an engine rotation From the number sensor 84,
Shift position S _H of the shift lever 60, an accelerator operation amount theta _AC, ON the brake, OFF, brake pedal force, ON the start switch 82, in addition to OFF, the signal indicative of engine rotational speed N _E is supplied, the engine torque T _E , Motor torque T _M , motor rotation speed N _M , input shaft rotation speed N _{I of the} automatic transmission 18, output shaft rotation speed (corresponding to the vehicle speed V) N _O , the charged amount SOC ₁ of the first power storage device 64, the second Information about the amount of charge SOC _{2 and the} like of the power storage device 56 is supplied from various detection means and the like. Engine torque T _E
Is obtained from the throttle valve opening, the fuel injection amount, and the like, the motor torque T _M is obtained from the motor current and the like, and the charged amounts SOC ₁ and SOC ₂ are obtained from the motor current and the charging efficiency during charging.

The hybrid control controller 40 includes:
For example, Japanese Patent Application No. 7-29414 filed earlier by the present applicant.
As described in No. 8, one of the eight operation modes shown in FIG. 6 is selected according to the flowchart shown in FIG. 5, and the engine 12 and the electric torque converter 24 are operated in the selected mode.

In FIG. 5, in step S1, it is determined whether or not a braking force is required, for example, whether or not the brake is ON.
The operation range of the shift lever 60 is an engine brake range such as L or 2 (a range in which shift control is performed only at a low speed shift stage and engine brake and regenerative braking are applied).
The determination is made based on whether the accelerator operation amount θ _AC is 0 or simply whether the accelerator operation amount θ _AC is 0 or not.

If this determination is affirmative, step S
Execute Step 2. In step S2, it is determined whether or not the state of charge SOC ₂ of the second power storage device 56 is equal to or greater than a predetermined maximum state of charge B. If SOC ₂ ≧ B, mode 8 is selected in step S3 and SOC ₂ < If B, mode 6 is selected in step S4. The maximum power storage amount B is determined by the second power storage device 56.
Is the maximum amount of power that is allowed to be charged with electric energy, and a value of, for example, about 80% is set based on the charging / discharging efficiency of the second power storage device 56 and the like.

Mode 8 selected in step S3
Is a first clutch CE _1, as shown in FIG. 6 engaged (ON), the second clutch CE ₂ engaged (ON), the motor generator 14 and the no-load state, the engine 12
Is stopped, that is, the throttle valve is closed, and the fuel injection amount is set to 0, whereby the braking force due to the rubbing rotation of the engine 12, that is, the engine brake is applied to the vehicle, and the brake operation by the driver is reduced. Driving operation becomes easy. In addition, since the motor generator 14 is in a no-load state and is freely rotated,
It is avoided that the electricity storage amount SOC ₂ of the second power storage device 56 impairs the performance of the charge-discharge efficiency and the like becomes excessive.

[0057] Mode 6 is selected in step S4, disengaging the first clutch CE ₁ As is apparent from FIG. 6 (OF
F), the second clutch CE ₂ is engaged (ON), the engine 12 is stopped, and the motor generator 14 is charged, and the motor generator 14 is rotationally driven by the kinetic energy of the vehicle. Second power storage device 56
And a regenerative braking force such as an engine brake is applied to the vehicle. Thereby, the brake operation by the driver is reduced, and the driving operation is facilitated.

Further, since the first clutch CE ₁ is released and the engine 12 is shut off, there is no energy loss due to rubbing of the engine 12 and the SOC 12
₂ <to be executed when the B, never storage amount SOC ₂ of the second power storage device 56 becomes excessive compromise the performance such as charge and discharge efficiency.

On the other hand, if the judgment in step S1 is negative, that is, if there is no request for the braking force, step S5
Is performed, and it is determined whether or not the start of the engine is requested, for example, based on whether the vehicle is stopped during traveling using the engine 12 as a power source such as mode 3, that is, whether or not the vehicle speed V = 0.

If this judgment is affirmed, step S6 is executed. In step S6, it is determined whether or not the accelerator is ON, that is, whether or not the accelerator operation amount θ _AC is larger than a predetermined value of substantially zero. If the accelerator is ON, mode 5 is selected in step S7 and the accelerator is ON. If not, mode 7 is selected in step S8.

Mode 5 selected in step S7
Is a first clutch CE ₁ As is apparent from FIG. 6 engaged (ON), and second releasing clutch CE ₂ (OFF),
With the engine 12 in the operating state, the motor generator 14
The vehicle is started by controlling the regenerative braking torque of the vehicle.

More specifically, assuming that the gear ratio of the planetary gear set 16 is ρ _E , engine torque T _E : output torque of the planetary gear set 16: motor torque T _M = 1: (1+
ρ _E ): ρ _E. For example, if the gear ratio ρ _E is set to about 0.5 which is a general value, the motor generator 14 shares half of the engine torque T _E , so that the engine torque T A torque about 1.5 times _E is output from the carrier 16c.

That is, a high torque start of (1 + ρ _E ) / ρ _E times the torque of motor generator 14 can be performed. Further, if the motor current is cut off to place the motor generator 14 in a no-load state, the rotor shaft 14r
Is only rotated in the reverse direction, the output from the carrier 16c becomes 0, and the vehicle stops.

That is, the planetary gear device 16 in this case functions as a starting clutch and a torque amplifying device. By gradually increasing the motor torque (regenerative braking torque) T _M from 0 to increase the reaction force, in (1 + ρ _E) times the output torque of the engine torque T _E it is possible to smoothly start the vehicle.

In this embodiment, a motor generator having a torque capacity approximately ρ _E times the maximum torque of the engine 12, that is, a motor generator 14 as small and small as possible while ensuring the required torque is used. ,
The device is compact and inexpensive.

In this embodiment, the output of the engine 12 is increased by increasing the throttle valve opening and the fuel injection amount in response to the increase in the motor torque T _M. thereby preventing engine stall or the like due to the reduction of the engine rotational speed N _E with.

[0067] Mode 7 is selected in step S8, engage the first clutch CE ₁ As is apparent from FIG. 6 (O
N), and second releasing clutch CE ₂ and (OFF), the engine 12 as a driving state, in which the electrically neutral motor-generator 14 as a no-load condition, the rotor shaft 14r is opposite direction of the motor-generator 14 The rotation of the input shaft 2 of the automatic transmission 18
The output for 6 becomes zero. Accordingly, it is not necessary to stop the engine 12 one by one when the vehicle is stopped while running using the engine 12 as a power source, such as in mode 3, and the engine can be started in mode 5 substantially.

On the other hand, if the determination in step S5 is negative, that is, if there is no request to start the engine, step S9 is executed to determine whether or not the required output Pd is equal to or less than a preset first determination value P1. I do. The required output Pd is an output necessary for traveling of the vehicle including the traveling resistance, and is based on the accelerator operation amount θ _AC , its change speed, the vehicle speed V (output shaft rotation speed N _O ), the gear position of the automatic transmission 18, and the like. , Calculated by a predetermined data map, an arithmetic expression, or the like.

The first determination value P1 is a boundary value between a medium load region where the vehicle runs only using the engine 12 as a power source and a low load region where the vehicle runs only using the motor generator 14 as a power source. In consideration of the energy efficiency, the exhaust gas amount, the fuel consumption amount, and the like are determined by experiments and the like so as to be as small as possible.

When the determination in step S9 is affirmative, that is, when the required output Pd is equal to or less than the first determination value P1,
Storage amount SOC ₂ it is determined whether the preset minimum storage amount A or more in step S10, selects the mode 1 in step S11 if the SOC ₂ ≧ A. On the other hand, SOC ₂ <
If A, mode 3 is selected in step S12.

The minimum amount of charge A is the minimum amount of charge allowed to extract electric energy from the second power storage device 56 when the vehicle runs using the motor generator 14 as a power source, and the charge / discharge efficiency of the second power storage device 56 For example, a value of about 70% is set based on the above.

[0072] The mode 1, the 7 released as apparent the first clutch CE ₁ from to (OFF), the second clutch CE ₂ engaged (ON), to stop the engine 12,
The motor generator 14 is driven to rotate at the required output Pd, and the vehicle runs using only the motor generator 14 as a power source.

Also in this case, since the first clutch CE ₁ is released and the engine 12 is shut off, the friction loss is small as in the case of the mode 6, and the efficiency of the automatic transmission 18 is controlled by appropriately shifting the speed. Good motor drive control is possible.

In the mode 1, the required output Pd is in a low load region where the required output Pd is equal to or less than the first determination value P1 and the second power storage device 56
Is executed when the storage amount SOC ₂ is equal to or more than the minimum storage amount A, the fuel efficiency and the exhaust gas can be reduced as compared with the case where the vehicle runs with the engine 12 as a power source, and the second power storage device 56 storage amount SOC ₂ of never drops below the minimum storage amount a compromise the performance such as charge and discharge efficiency.

The mode 3 selected in step S12 is
As is clear from FIG. 6, the first clutch CE ₁ and the second clutch CE ₁
The clutch CE ₂ is engaged (ON) together, the engine 12 is driven, the motor generator 14 is charged by regenerative braking, and is generated by the motor generator 14 while the vehicle is running at the output of the engine 12. The second energy storage device 56 is charged with electric energy. The engine 12 is operated at an output higher than the required output Pd, and the current control of the motor generator 14 is performed so that the motor generator 14 consumes a marginal power greater than the required output Pd.

On the other hand, if the determination in step S9 is negative, that is, if the required output Pd is larger than the first determination value P1, in step S13, the required output Pd
Is greater than the first determination value P1 and less than the second determination value P2, that is, whether P1 <Pd <P2.

The second judgment value P2 is a boundary value between a middle load region where the vehicle runs only using the engine 12 as a power source and a high load region where the vehicle runs using both the engine 12 and the motor generator 14 as the power sources. In consideration of energy efficiency including time, exhaust gas amount, fuel consumption amount and the like are determined in advance by experiments and the like so as to minimize the amount of exhaust gas and fuel consumption.

[0078] Then, P1 <determines whether SOC ₂ ≧ A in step S14 if Pd <P2, SOC ₂ ≧ A
In the case of, mode 2 is selected in step S15 and the SOC
_{If 2} <A, mode 3 is selected in step S12.

If Pd ≧ P2, step S16
In determining whether SOC ₂ ≧ A, in the case of SOC ₂ ≧ A selects the mode 4 in the step S17, when the SOC ₂ <A selects the mode 2 in step S15.

In the mode 2, the first clutch CE ₁ and the second clutch CE ₂ are both engaged (ON), the engine 12 is operated at the required output Pd, and the motor generator 14 is operated, as is apparent from FIG. Under no load condition, the vehicle is run using only the engine 12 as a power source.

In the mode 4, the first clutch CE ₁ and the second clutch CE ₂ are both engaged (ON), the engine 12 is operated, and the motor generator 14 is driven to rotate. The vehicle is caused to travel at a high output using both of the generators 14 as power sources.

Mode 4 is executed in a high load region where the required output Pd is equal to or greater than the second determination value P2.
And the motor generator 14 are used together, so that the energy efficiency is not significantly impaired as compared with the case where the vehicle runs using only one of the engine 12 and the motor generator 14 as a power source, and the fuel consumption and exhaust gas can be reduced. . Further, since the process is executed when the storage amount SOC ₂ is equal to or more than the minimum storage amount A, the storage amount S of the second power storage device 56
OC ₂ does not drop below the minimum charge amount A to impair the performance such as charging and discharging efficiency.

To summarize the operating conditions of modes 1 to 4, if the state of charge SOC ₂ ≧ A, in the low load region of Pd ≦ P1, mode 1 is selected in step S11 and only motor generator 14 is used as the power source. Drive and P1 <
In the medium load region where Pd <P2, the mode 2 is set in step S15.
Is selected and the vehicle runs using only the engine 12 as a power source.
In the high load region of 2 ≦ Pd, mode 4 is selected in step S17, and the vehicle travels using both the engine 12 and the motor generator 14 as power sources.

When SOC ₂ <A, the second power storage device 56 is charged by executing the mode 3 of step S12 in the middle and low load region where the required output Pd is smaller than the second determination value P2. In the high load region where the required output Pd is equal to or greater than the second determination value P2, mode 2 is selected in step S15, and the engine 12 performs high output traveling without charging.

The mode 2 of step S15 is such that P1 <Pd
<P2 in the middle load region and SOC ₂ ≧ A, or in the high load region of Pd ≧ P2 and SOC ₂ <A, but in the middle load region, the engine 12 is generally more driven than the motor generator 14. Since the energy efficiency is superior, the fuel consumption and the exhaust gas can be reduced as compared with the case where the vehicle runs using the motor generator 14 as a power source.

In the high load range, the vehicle travels in mode 4 in which the motor generator 14 and the engine 12 are used together.
However, when the state of charge SOC ₂ of the second power storage device 56 is smaller than the minimum power storage amount A, the operation in the mode 2 using only the engine 12 as a power source is performed. The storage amount SOC ₂ is the minimum storage amount A
Thus, it is possible to prevent the performance from being impaired, such as charge and discharge efficiency.

Next, a characteristic portion of the present embodiment to which the present invention is applied, that is, a control operation for maintaining the engine 12 as drivable as possible will be described with reference to a flowchart of FIG.

In FIG. 7, in step SA1, various input signals are sequentially processed by the hybrid control controller 40. Next, in step SA2, it is determined whether or not the state of charge SOC1 of _first power storage device 64 is equal to or greater than a predetermined value α. The predetermined value α is set to an amount of electric power sufficient to drive the engine 12. If this determination is denied, in the next step SA3, the second power storage device 56
It is determined whether or not the state of charge SOC ₂ is equal to or smaller than a predetermined value β. The predetermined value β is also set to an amount of electric power sufficient to drive engine 12.

If the determination in step SA3 is negative, in step SA4, under the control of the hybrid control controller 40, the discharge output of the second power storage device 56 is converted to a lower voltage by the voltage conversion control device 62. Then, the first power storage device 64 is charged by being supplied to the first power storage device 64 side.

On the other hand, if the determination in step SA3 is affirmative, it is determined in step SA5 whether or not there is an engine start request, for example, whether or not the start switch 84 has been turned on, in other words, whether the driver intends to move the vehicle. It is determined by whether or not it has. As the start switch 84, an ignition switch or the like is suitably used. Note that an engine start request may be made at the discretion of the hybrid control controller 40.

If the determination in step SA5 is affirmative, in step SA7 the first power storage device 64 is charged in the same manner as in step SA4, and the engine 12 is rotated by the starter to start the engine 12. Perform control. By switching the changeover switch 55 to the second connection state without charging the first power storage device 64, the auxiliary devices 67 are converted to the low voltage by the voltage conversion control device 62 from the second power storage device 56. (A starter or the like) can be directly driven to start the engine 12. On the other hand, if this determination is denied, step SA
In 6, the charge from the second power storage device 56 to the first power storage device 64 is stopped by the hybrid control controller 40.

Next, at step SA8, it is determined whether or not the engine 12 has started based on a signal from the engine speed sensor 84. If this decision is denied,
Step SA7 is repeated to continue charging of first power storage device 64 until engine 12 is started. If this determination is affirmed, in step SA9, mode 3 or mode 5 in FIG. 6 is executed. Then, second power storage device 56 is charged with electric power generated by regenerative braking of motor generator 14. Note that charging of the first power storage device 64 is also continued to maintain the operation of the engine 12.

As described above, according to the present embodiment, when the state of charge SOC ₂ of the second power storage device 56 is equal to or less than the predetermined value β,
Since charging from the second power storage device 56 to the first power storage device 64 is prohibited except when there is a request to start the engine 12, even if the power of the first power storage device 64 is consumed by turning on a headlight or the like, When the engine 12 is started, the second power storage device 5
6, the first power storage device 64 is charged, and the changeover switch 55 is switched to the first connection state to switch the first power storage device 6.
4 drives the auxiliary devices 67 (starter), or switches the switch 55 without charging the first power storage device 64.
Is switched to the second connection state, and the auxiliary equipment 67 (starter) can be directly driven by the electric power from the second power storage device 56 converted to a low voltage by the voltage conversion device 62, thereby starting the engine 12. Becomes

The hybrid control controller 4
0 in a series of signal processing by step SA in FIG.
The portions that execute 3, SA4, SA5, and SA6 constitute charging means together with the voltage conversion control device 62. In addition, step SA3 of them functions as a storage amount determination unit of the second power storage device 56, step SA5 functions as an engine start request determination unit, and step SA6 functions as a charging stop unit.

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

For example, in the above-described embodiment,
Although the automatic transmission 18 having five speeds and five forward speeds has been used, as shown in FIG. 8, the automatic transmission 80 including only the main transmission 22 without the sub-transmission 20 is used. It is also possible to adopt the above, and to perform the shift control at four forward speeds and one reverse speed as shown in FIG.

The present invention can be applied in various other modes without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of a hybrid drive device of a hybrid vehicle including a control device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a control system of the hybrid drive device of FIG.

FIG. 3 is a diagram illustrating the operation of an engagement element that establishes each shift speed of the automatic transmission of FIG. 1;

FIG. 4 is a diagram showing a part of a hydraulic circuit of the automatic transmission of FIG. 1;

FIG. 5 is a flowchart illustrating a basic operation of the hybrid drive device of FIG. 1;

FIG. 6 shows each mode 1 to 8 in the flowchart of FIG.
It is a figure explaining the operation state of.

FIG. 7 is a flowchart illustrating a main part of a control operation that is a feature of the present invention.

FIG. 8 is a skeleton view illustrating a configuration of a hybrid drive device including an automatic transmission different from the embodiment of FIG. 1;

9 is a diagram illustrating the operation of an engagement element that establishes each shift speed of the automatic transmission in FIG.

[Explanation of symbols]

 12: Engine 14: Motor generator (electric motor) 56: Second power storage device 64: First power storage device 62: Voltage conversion control device (charging means) Steps SA3 to SA6: Charging means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yushi Hata 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Tsuyoshi Mika 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (1)

[Claims] 1. An engine, which operates by burning fuel, and an electric motor, which operates by electric energy, are provided as power sources for driving a vehicle, and a first power source for supplying electric power to accessories for driving the engine is provided. A control device for a hybrid vehicle, comprising: a power storage device; and a second power storage device for supplying power to the electric motor, wherein the control device for a hybrid vehicle includes charging means for charging the first power storage device from the second power storage device. A controller for changing the charging of the first power storage device from the second power storage device in accordance with the amount of power stored in the second power storage device.