JP2000170903A - Control device for power train - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve regenerative braking efficiency of a motor/generator. SOLUTION: A control device for a power train has followings: a motor/ generator which functions as a generator due to power input from an engine or wheels, a torque converter with a lock-up clutch arranged between the motor/ generator and the wheels, and a gear transmission mechanism arranged between the torque converter and the wheels. In such a control device, a regenerative braking condition control means (operated in steps 101 and/or 106) is arranged for controlling at least engagement/disengagement conditions of the lock-up clutch so as to obtain maximum regenerative braking efficiency in the case where the motor/generator is operated as the generator based on the power input from the wheels, among such conditions as rengenerative torque of the motor/generator, engagement/disengagement conditions of the lock-up clutch, and the transmission gear ratio of the gear transmission mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power train which includes an engine and a motor generator as a power source of a vehicle, and is capable of performing regenerative braking by the motor generator using power input from wheels. It concerns the device.

[0002]

2. Description of the Related Art In recent years, an engine and a motor / generator have been mounted for the purpose of saving fuel for driving an engine, reducing noise due to rotation of the engine, and reducing exhaust gas generated by fuel combustion. Hybrid vehicles have been proposed. In this hybrid vehicle, the engine or motor
The vehicle is driven by controlling the generator.

As described above, an example of a control device having an engine and a motor generator is disclosed in Japanese Patent Laid-Open No. 8-168.
No. 104 publication. In the control device described in this publication, a motor generator is provided on the output shaft of the engine, and this motor generator functions as an electric motor and a generator. A transmission is connected to the output shaft of the engine via a torque converter. Note that the torque converter has a direct coupling clutch.

According to the above control device, the torque of the motor / generator is controlled so as to absorb the fluctuation of the engine torque in the low speed rotation range of the engine.
The engagement of the direct coupling clutch in a low vehicle speed range is enabled. As a result, it is described that fuel efficiency is improved and drivability can be prevented from deteriorating.

[0005]

However, the above-mentioned publication only describes a technique in a case where the motor / generator functions as an electric motor, that is, a technique in the case where the motor / generator is used as a power source of a vehicle. That is, there is no description on the control in the case where the regenerative braking torque is generated by the motor / generator, in particular, how to control the direct coupling clutch during the regenerative braking of the motor / generator. Therefore, during regenerative braking by the motor / generator, various problems may occur based on the state of the direct coupling clutch, and there is room for improvement in this respect.

The present invention has been made in view of the above circumstances, and can solve various problems that occur based on the state of a direct coupling clutch when a regenerative braking torque is generated by a motor generator. It is an object of the present invention to provide a power train control device.

[0007]

In order to achieve the above object, the present invention provides a motor generator functioning as a generator by power input from an engine or power input from wheels. A fluid power transmission device disposed between a motor / generator and the wheels, a direct coupling clutch engaged / disengaged to switch a power transmission state between rotating members of the fluid power transmission device, and the fluid And a transmission disposed between the power transmission device and the wheels, and controlling a power train capable of transmitting power input from the wheels to the motor generator to generate regenerative braking torque. In the apparatus, the regenerative braking torque of the motor / generator or the regenerative braking torque of the motor / generator is set so that the regenerative braking efficiency of the motor / generator is in a predetermined state. Is provided with regenerative braking condition control means for controlling at least a condition including an engaged / disengaged state of the direct-coupled clutch among the conditions of the engaged / disengaged state of the direct-coupled clutch or the gear ratio of the transmission. It is a feature.

According to the first aspect of the invention, the regenerative braking torque of the motor / generator, the engaged / disengaged state of the direct coupling clutch, or the transmission of the transmission is controlled so that the regenerative braking efficiency of the motor / generator is in a predetermined state. Among the conditions of the gear ratio, at least the conditions including the engaged / disengaged state of the direct coupling clutch are controlled. Therefore, for example, the regenerative braking efficiency of the motor generator can be improved as much as possible.

According to a second aspect of the present invention, a first rotating member connected to an engine, a second rotating member connected to wheels, and transmission of power between the first rotating member and the second rotating member. A hydraulic power transmission device, a motor generator for generating regenerative braking torque by power input from the wheels, and a power transmission state between the first rotating member and the second rotating member. In a power train control device having a directly-coupled clutch to be engaged / disengaged and a rotating machine for transmitting power to the engine, an engaged / disengaged state of the direct-coupled clutch is reduced during regenerative braking by the motor / generator. A direct-coupled clutch control means for changing the engagement / release state of the direct-coupled clutch so as to reduce a difference between the engine speed and the speed of the second rotating member. That the power of the rotating machine and a rotating machine control means for imparting to the engine is characterized in.

According to the second aspect of the present invention, the difference between the engine speed and the speed of the second rotary member is reduced in changing the engaged / disengaged state of the direct coupling clutch during regenerative braking by the motor / generator. Thus, the power of the rotating machine is controlled. Therefore, when the direct coupling clutch is switched from the disengaged state to the engaged state in parallel with the regenerative braking by the motor / generator, the difference between the engine speed and the speed of the second rotating member is suppressed as much as possible. The direct clutch engages.

[0011]

Next, the present invention will be described more specifically with reference to the drawings. FIG. 2 is a block diagram showing a system configuration of a hybrid vehicle to which the present invention is applied. As the engine 1, which is the first power source of the vehicle, an internal combustion engine such as a gasoline engine, a diesel engine, or an LPG engine is used. Engine 1 of this embodiment
Has a known structure including a fuel injection device, an intake / exhaust device, an ignition device, and the like.

An electronic throttle valve 1B is provided in an intake pipe of the engine 1 so that the opening of the electronic throttle valve 1B is electrically controlled. In a power transmission path (in other words, a torque transmission path) of the engine 1, a torque converter 2, a motor generator 3, and a gear transmission mechanism 4 are arranged in series. In this embodiment, the motor generator 3 is arranged between the engine 1 and the torque converter 2, and the torque converter 2 is arranged between the motor generator 3 and the gear transmission mechanism 4.

The motor generator 3 has a function as a second power source of the vehicle. For example, an AC synchronous type is applied to the motor generator 3. motor·
The generator 3 includes a rotor (not shown) having a permanent magnet, and a stator (not shown) around which a coil (not shown) is wound. When a three-phase alternating current flows through the three-phase winding of the coil, a rotating magnetic field is generated, and torque is generated by controlling the rotating magnetic field according to the rotation position and the rotation speed of the rotor. The generated torque is almost proportional to the magnitude of the current, and the rotation speed is controlled by the frequency of the alternating current.

On the other hand, a battery 81 is connected to the motor / generator 3 via an inverter 80, and the motor / generator 3, the inverter 80 and the battery 8 are connected.
1 is provided. The inverter 80 converts the DC current of the battery 81 into a three-phase AC current and supplies the three-phase AC current to the motor generator 3, while converting the three-phase AC current generated by the motor generator 3 into a DC current and outputs the DC current to the battery 81. A three-phase bridge circuit (not shown) is provided. The three-phase bridge circuit includes, for example, six power transistors (not shown).
Are electrically connected to each other. By switching on / off of these power transistors, the direction of the current between motor generator 3 and battery 81 is switched. In this way, the mutual conversion between the three-phase AC current and the DC current, the adjustment of the frequency of the three-phase AC current applied to the motor generator 3, and the conversion of the three-phase AC current applied to the motor generator 3 are performed. Adjustment of the magnitude and adjustment of the regenerative braking torque of the motor generator 3 are performed.

The motor generator 3 having the above configuration has a function of mutually converting between mechanical energy and electric energy, that is, a function as a motor and a function as a generator. When the motor / generator 3 functions as an electric motor, the DC voltage from the battery 81 is converted into an AC voltage and supplied to the motor / generator 3. When the motor generator 3 functions as a generator, the induction voltage generated by the rotation of the rotor is converted into a DC voltage by the inverter 80 and the battery 81 is charged.

The controller 82 controls the battery 8
It has a function of detecting or controlling a current value supplied from 1 to the motor generator 3 or a current value generated by the motor generator 3. The controller 82 has a function of controlling the number of revolutions of the motor generator 3 and a state of charge (SOC: stateof
charge) is detected and controlled.

FIG. 3 is a skeleton diagram showing a configuration of a power train formed between the engine 1 and the wheels 32A, specifically, a configuration of the torque converter 2 and the gear transmission mechanism 4. An automatic transmission fluid (hereinafter abbreviated as ATF or oil) as a working fluid is sealed in a casing 35 of the automatic transmission having the torque converter 2 and the gear transmission mechanism 4. An oil pump 83 is provided inside the casing 35. The power of the engine 1 is transmitted to the oil pump 83 via the pump impeller 7 so that the oil pump 83 is driven.

[0018] The torque converter 2 is a type of fluid power transmission device and has a torque amplifying function. The torque converter 2 transmits the power of the driving-side rotating member to the driven-side rotating member via oil. The torque converter 2 has a front cover 8 integrated with a pump impeller 7, a hub 10 integrally mounted with a turbine runner 9, and a lock-up clutch 11. The lock-up clutch 11 is configured to be able to be engaged (on) and released (off). When the lock-up clutch 11 is released, the torque between the pump impeller 7 and the turbine runner 9 is reduced by oil. Communication takes place. When the lock-up clutch 11 is engaged, the front cover 8 and the hub 10 are mechanically connected.

A stator 13 is provided on the inner peripheral side of the pump impeller 7 and the turbine runner 9.
The stator 13 is for amplifying the torque transmitted from the pump impeller 7 to the turbine runner 9. Further, an input shaft 14 is connected to the hub 10. Therefore, when torque is output from the crankshaft 12 of the engine 1, this torque is transmitted to the input shaft 14 via the ATF or the lock-up clutch 11. Conversely, the torque transmitted from the wheel 32A to the input shaft 14 is transmitted to the ATF or the lock-up clutch 11
Can also be transmitted to the engine 1 via the.

The gear transmission mechanism 4 includes an auxiliary transmission section 15 and a main transmission section 16. The auxiliary transmission unit 15
An overdrive planetary gear mechanism 17 is provided, and an input shaft 14 is connected to a carrier 18 of the planetary gear mechanism 17. A multi-plate clutch C0 and a one-way clutch F0 are provided between the carrier 18 and the sun gear 19 constituting the planetary gear mechanism 17. The one-way clutch F0 is engaged when the sun gear 19 rotates forward relative to the carrier 18, that is, when the sun gear 19 rotates in the rotation direction of the input shaft 14. The ring gear 20, which is an output element of the sub transmission unit 15, is
Is connected to the intermediate shaft 21 which is an input element of. Also,
Multi-plate brake B0 for selectively stopping rotation of sun gear 19
Is provided.

Therefore, the entire sub-transmission portion 15 rotates integrally with the planetary gear mechanism 17 with the multi-plate clutch C0 or the one-way clutch F0 engaged. For this reason, the intermediate shaft 21 rotates at the same speed as the input shaft 14 and is in the low speed stage. Further, the brake B0 is engaged to
Is stopped, the ring gear 20 is rotated by the input shaft 14.
The rotation speed is increased with respect to the normal rotation, and a high speed stage is established.

On the other hand, the main transmission section 16 is provided with three sets of planetary gear mechanisms 22, 23 and 24, and the rotating elements constituting the three sets of planetary gear mechanisms 22, 23 and 24 are connected as follows. Have been. That is, the sun gear 25 of the first planetary gear mechanism 22 and the sun gear 26 of the second planetary gear mechanism 23 are integrally connected to each other. Also, the ring gear 27 of the first planetary gear mechanism 22, the carrier 29 of the second planetary gear mechanism 23, and the carrier 31 of the third planetary gear mechanism 24
And are connected. Further, the output shaft 3 is attached to the carrier 31.
2 are connected. The output shaft 32 is connected to the wheels 32A via a torque transmission device (not shown). Furthermore, the ring gear 3 of the second planetary gear mechanism 23
3 is connected to the sun gear 34 of the third planetary gear mechanism 24.

In the gear train of the main transmission section 16, one reverse gear and four forward gears can be set. A friction engagement device for setting such a shift speed, that is, a clutch and a brake, is provided as follows. First, the clutch will be described. The ring gear 33 and the sun gear 34, the intermediate shaft 21
Between the first clutch C1 and the first clutch C1. Further, a second clutch C2 is provided between the sun gear 25 and the sun gear 26 connected to each other and the intermediate shaft 21.

Next, the brake will be described. The first brake B1 is a band brake, and is arranged so as to stop the rotation of the sun gear 25 of the first planetary gear mechanism 22 and the sun gear 26 of the second planetary gear mechanism 23. I have. Between the sun gears 25 and 26 and the casing 35, a first one-way clutch F1 and a second brake B2, which is a multi-disc brake, are arranged in series. The first one-way clutch F1 is engaged when the sun gears 25 and 26 rotate in the reverse direction, that is, when they rotate in the direction opposite to the rotation direction of the input shaft 14.

A carrier 37 of the first planetary gear mechanism 22;
A third brake B3, which is a multiple disc brake, is provided between the casing and the casing 35. And the third planetary gear mechanism 2
Reference numeral 4 denotes a ring gear 38. As a brake for stopping the rotation of the ring gear 38, a fourth brake B4, which is a multi-plate brake, and a second one-way clutch F2 are provided. Fourth brake B4 and second one-way clutch F2
Are arranged in parallel with each other between the casing 35 and the ring gear 38. The second one-way clutch F
2 is configured to engage when the ring gear 38 is about to rotate in the reverse direction. Further, an input rotation speed sensor (in other words, a turbine rotation speed sensor) 4A for detecting an input rotation speed of the gear transmission mechanism 4, and an output shaft 3 of the gear transmission mechanism 4
An output rotation speed sensor (in other words, a vehicle speed sensor) 4B for detecting the rotation speed of the second motor 2 is provided.

In the gear transmission mechanism 4 configured as described above, frictional engagement devices such as clutches and brakes are engaged and released as shown in the operation chart of FIG. The first reverse speed can be set. In FIG. 4, the mark ○ indicates that the friction engagement device is engaged, the mark ◎ indicates that the friction engagement device is engaged during engine braking, and the mark △ indicates that the friction engagement device is engaged. It can be either release, in other words, that the engagement of the friction engagement device has nothing to do with the transmission of torque, and a blank indicates that the friction engagement device is released.

In this embodiment, the shift lever 4
It is possible to select the position of the automatic transmission by manual operation of C. For example, P (parking)
Position, R (reverse) position, N (neutral) position, D (drive) position, 4 position, 3 position, 2 position, and L (low) position can be selected. Here, the P position and the N position are non-traveling positions, and the R position, D position, 4 positions, 3 positions, 2 positions, and L position are traveling positions.

In the D position, any of the first to fifth speeds can be set. In the four position, any of the first to fourth speeds can be set. In the position, any of the first to third speeds can be set, in the two position, either the first speed or the second speed can be set, and in the L (low) position, the first or third speed can be set. The first gear is set.

The hydraulic control device 39 shown in FIG.
Is a control of a gear position set by the gear transmission mechanism 4,
Control of engagement / disengagement of the lock-up clutch 11, control of line pressure of a hydraulic circuit connected to the friction engagement device,
It has a function of controlling the engagement pressure of the friction engagement device. In this embodiment, the lock-up clutch 11 is engaged in a fully engaged state in which the friction members do not rotate relative to each other in the power transmission state, and a slip state in which the friction members rotate relative to each other in the power transmission state. Is included.

The hydraulic control device 39 is electrically controlled, and is a first control for executing a shift of the gear transmission mechanism 4.
Or a third shift solenoid valve S1,.
A fourth solenoid valve S4 for controlling the engine braking state. Further, the hydraulic control device 39
Are a linear solenoid valve SLT for controlling the line pressure of the hydraulic circuit, a linear solenoid valve SLN for controlling the back pressure of the accumulator during a shift transition of the gear transmission mechanism 4, a lock-up clutch 11 and a predetermined frictional clutch. A linear solenoid valve SLU for controlling the hydraulic pressure acting on the combined device.

A motor generator 85 is provided on the other power transmission path of the engine 1 via a drive unit 84. The driving device 84 includes a planetary gear mechanism 84A.
, A one-way clutch 85B, a brake 84C for selectively fixing a rotating element of the planetary gear mechanism 84A, and a clutch 84D for connecting / disconnecting a power transmission path between the driving device 84 and the crankshaft 12. It has a known structure. Motor generator 85 is configured similarly to motor generator 3. Further, the battery 8 is connected to the motor generator 85 via an inverter 86.
7 is connected. Further, a controller 88 for controlling the inverter 86 and the battery 87 is provided.

The configurations and functions of the controller 88, the battery 87, and the inverter 86 are the same as those of the controller 82, the battery 81, and the inverter 8
0 has the same configuration and function. The motor generator 85 also has a function as a generator and a function as an electric motor. Therefore, the motor
By causing the generator 85 to function as an electric motor, the power of the motor generator 85 is transmitted to the engine 1 or a part of the power of the engine 1 is transmitted to the motor generator 85 so that the motor generator 85 functions as a generator. , It is possible to charge the battery 87 with the electric energy. When power is transmitted between the motor / generator 3 and the engine 1,
The clutch 84D of the driving device 84 is engaged.

The controller 88 has a function of detecting or controlling a current value supplied from the battery 87 to the motor generator 85 or a current value generated by the motor generator 85. Also,
The controller 88 has a function of controlling the number of revolutions of the motor generator 85 and a state of charge (SO
C: a function of detecting and controlling a state of charge).

FIG. 5 is a block diagram showing a control circuit of the hybrid vehicle. The electronic control unit (ECU) 58 includes a central processing unit (CPU) and a storage device (RAM, R
OM) and a microcomputer mainly composed of an input / output interface.

The electronic control unit 58 includes a signal from an engine speed sensor 59, a signal from an engine water temperature sensor 60,
A controller 8 for separately detecting a signal of an ignition switch 61 for detecting an operation position of an ignition key 90 operated by a driver, a state of charge of batteries 81 and 87, and a current value of motor generators 3 and 85.
2, 88, an air conditioner switch 62, a vehicle speed sensor 4B, an oil temperature sensor 6 for detecting the temperature of the ATF.
3, a signal from a shift position sensor 64 for detecting the operation position of the shift lever 4C, and the like.

The electronic control unit 58 includes a signal of a parking brake switch 65 for detecting a driver's intention to stop, a signal of a foot brake switch 66 for detecting a depressed state of a brake pedal 91, and a signal of an exhaust pipe (not shown). A signal from a catalyst temperature sensor 67 provided on the way, an accelerator opening sensor 68 indicating an amount of depression of an accelerator pedal 1A
, A signal from a throttle opening sensor 69 indicating the opening of the electronic throttle valve 1B of the engine 1, a signal from the turbine speed sensor 4A, resolvers 70 and 71 for detecting the rotation speed and rotation angle of the motor generators 3 and 85. Is input.

The hybrid vehicle includes a brake device 91A including a brake pedal 91, a brake master cylinder (not shown), a wheel cylinder (not shown), and the like. A braking force is generated.

From the electronic control unit 58, the engine 1
For controlling the ignition device 72 of the engine 1, a signal for controlling the fuel injection device 73 of the engine 1, a signal for controlling the motor generators 3 and 85 via the controllers 82 and 88, a signal for controlling the drive device 84, a hydraulic control device Signals for controlling the operation of the electronic throttle valve 1B, a control signal for an actuator 75 for controlling the opening of the electronic throttle valve 1B, and the like are output.

In the hybrid vehicle having the above-described hardware configuration, the state of the vehicle is determined based on a signal input to the electronic control unit 58, and the engine 1, the motor generator 3, and the motor
Generator 85 is controlled. Then, at least one of the power of the engine 1 and the power of the motor generator 3 can be transmitted to the wheels 32A to cause the vehicle to travel.

When the vehicle is decelerating (in other words, when coasting), the power (ie, kinetic energy) input from the wheels 32A is input to the engine 1 via the gear transmission mechanism 4 and the torque converter 2. Then, an engine braking force is generated. Further, by inputting this power to the motor / generator 3, the motor / generator 3 can function as a generator, and the motor / generator 3 can generate a regenerative braking force. In this case, electric energy generated by motor generator 3 is charged in battery 81.

Here, the correspondence between the configuration of the hybrid vehicle having the above hardware configuration and the configuration of the present invention will be described. That is, the lock-up clutch 11 corresponds to the direct coupling clutch of the present invention, the torque converter 2 corresponds to the hydraulic power transmission device of the present invention, the gear transmission mechanism 4 corresponds to the transmission of the present invention, and the motor generator 3 , 85
However, it also has the function as the rotating machine of the present invention. The front cover 8 and the pump impeller 7 correspond to the first rotating member of the present invention, and the hub 10 and the input shaft 14
Corresponds to the second rotating member of the present invention.

Next, the details of control of the gear transmission mechanism 4, the hydraulic control device 39, and the lock-up clutch 11 by the electronic control device 58 will be described. The electronic control unit 58 stores a shift diagram (shift map) for controlling the gear ratio of the gear transmission mechanism 4. In this shift diagram, shift points for shifting (upshifting or downshifting) from a predetermined shift speed to another shift speed are set using the running state of the vehicle, for example, the accelerator opening and the vehicle speed as parameters. I have.

A shift determination is made based on the shift diagram. If the shift determination is made, a control signal is output from the electronic control unit 58 and the control signal is input to the hydraulic control unit 39. . As a result, a predetermined solenoid valve is operated, a predetermined friction engagement device is engaged / disengaged, and a shift is performed. Then, the timing of engagement / disengagement of the friction engagement device for executing the shift and the hydraulic pressure acting on the friction engagement device are controlled based on the engine torque.

The lock-up clutch 11 is controlled based on a shift position, an accelerator opening, a vehicle speed, and a gear ratio (gear position) of the gear transmission mechanism 4. For this reason, a lock-up clutch control map in which each area of the complete engagement, slip, and release of the lock-up clutch 11 is set using the accelerator opening and the vehicle speed as parameters,
It is stored in the electronic control unit 58.

By the way, in this embodiment, in addition to the above conditions, when the regenerative braking of the motor / generator 3 is performed,
The motor and motor are controlled so that the regenerative braking efficiency is in the specified state.
It is possible to control the regenerative braking torque of the generator 3, the engaged / slip / disengaged state of the lock-up clutch 11, and the gear position of the gear transmission mechanism 4.

Hereinafter, the control contents during regenerative braking of the motor generator 3 will be described with reference to the flowchart of FIG. First, signals from various sensors and switches are input to the electronic control unit 58, and these signals are processed (step 100). Then, motor generator 3
It is determined whether or not the condition for performing the regenerative braking is established (step 101). The conditions used in step 101 include the state of accelerator pedal 1A and the state of charge SOC of battery 81. Here, if the accelerator pedal 1A is depressed, a negative determination is made in step 101 and the routine returns.

Conversely, if the accelerator pedal 1A is not depressed and the state of charge SOC of the battery 81 is equal to or less than the predetermined value, an affirmative determination is made in step 101 and the routine proceeds to step 102. In step 102, the gear position of the gear transmission mechanism 4 is determined based on the shift diagram for regenerative braking.

FIG. 6 shows an example of a shift diagram.
In this shift diagram, shift points for shifting from a predetermined shift speed to another shift speed are set using the running state of the vehicle, for example, the accelerator opening and the vehicle speed as parameters. In this shift diagram, a shift line for upshifting from a predetermined shift speed to a predetermined shift speed is indicated by a solid line, and a shift line for downshifting from a predetermined shift speed to a predetermined shift speed is indicated by a chain line. Indicated by In other words, the numbers shown in this shift diagram mean the respective shift speeds, and the arrows described corresponding to the numbers indicate that the upshift or downshift from the numeric shift speed to the numeric shift speed is performed. Means.

In step 102, it is determined whether or not the lock-up clutch 11 is in a region where the lock-up clutch 11 is completely engaged or in a region where slip control is performed (step 10).
3). In making the determination in step 103, a part of the shift diagram shown in FIG. 6 is applied as a lock-up clutch control map. In this embodiment, when the fourth speed or the fifth speed is set, control for completely engaging or slipping the lock-up clutch 11 is performed, and in the first to third speeds, the lock-up clutch 11 is controlled.
Is released.

More specifically, in the region 4S set between the upshift line from the third speed to the fourth speed and the upshift line from the fourth speed to the fifth speed, the lock-up clutch 11 Is slip-controlled. Further, in a region 4L set between the upshift line from the third speed to the fourth speed and the upshift line from the fourth speed to the fifth speed,
The lock-up clutch 11 is completely engaged. further,
In a region 5S which is a part of the region where the fifth speed is set, the lockup clutch 11 is slip-controlled.
Furthermore, in a region 5L that is a part of the region where the fifth speed is set, lock-up clutch 11 is completely engaged. The lock-up clutch control map applied at the time of regenerative braking is more effective than the lock-up clutch control map applied at times other than the time of regenerative braking. It is the content to be done.

If a negative determination is made in step 103,
Returning to step 102, the gear is forcibly changed from the current gear to a gear in which the lock-up clutch 11 is completely engaged or slip controlled. On the other hand, if a positive determination is made in step 103, the regenerative braking torque of the motor generator 3 is determined (step 104). For example, when the brake pedal 91 is depressed to generate a braking request during regenerative braking of the motor / generator 3, the braking force to be borne by the braking device 91A and the battery 81
Generator 3 based on the state of charge SOC
Determines the regenerative braking torque to be borne.

In step 105, the lock-up clutch 11 is completely engaged or slip-controlled based on the regenerative braking lock-up clutch control map. Here, when the slip control of the lock-up clutch 11 is performed, the slip amount (or the slip rate) of the lock-up clutch 11 is temporarily determined (step 1).
05). Then, steps 102 to 105
It is determined whether or not the regenerative braking efficiency η of the motor generator 3 achieved by the above control is maximized (step 106). The method of calculating the regenerative braking dynamic efficiency η is based on the time of complete engagement control of the lock-up clutch 11, the time of slip of the lock-up clutch 11,
Since they are different from each other when they are released, they will be described sequentially.

(A) When the lock-up clutch 11 is fully engaged When the motor / generator 3 is regeneratively braked, the input shaft 14
Are input to the engine 1. Here, if the torque ΔT required for rotation of the engine 1 is ΔT ≒ 0,
The regenerative braking efficiency η of the motor / generator 3 is obtained by the following equation (1). η = ηg × ηM (× ηBATT) (1) In the above equation (1), ηg is the gear efficiency of the gear transmission mechanism 4. ΗM is the motor efficiency (power generation efficiency) of the motor generator 3. That is, the conversion efficiency when kinetic energy is converted into electric energy. The motor efficiency ηM is determined based on the rotational speed NM of the motor generator 3 and the regenerative braking torque TM.

FIG. 7 shows an example of the motor efficiency distribution using the rotation speed NM of the motor generator 3 and the regenerative torque (negative torque) TM as parameters. Further, η BATT is a charging efficiency when the battery 81 is charged with the electric energy generated by the motor generator 3. In equation (1), (× ηBATT) means that it is possible to arbitrarily select whether or not to take into account the battery charging efficiency ηBATT when calculating the regenerative braking efficiency η.

(B) At the time of slip control of the lock-up clutch 11 The regenerative braking efficiency η of the motor generator 3 is obtained by the following equation (2).

(Equation 1) In the above equation (2), t is the torque ratio of the torque converter 2, Tl is the shared torque of the lock-up clutch 11, TLOAD is the running load of the vehicle, and ig is the gear ratio of the gear transmission mechanism 4 (gear). No) is the number of revolutions of the output shaft 32 of the gear transmission mechanism 4, and ΔN is the slip amount (slip ratio) of the lock-up clutch 11.

(C) When the lock-up clutch 11 is released The regenerative braking efficiency η of the motor generator 3 can be obtained by the following equation (3) if the torque ΔT required for rotation of the engine 1 is ΔT ≒ 0. .

(Equation 2) In the above equation (3), ηtc is the efficiency of the torque converter 2 and is obtained by ηtc = (turbine rotation speed × torque) / (rotation speed of pump impeller 7 × torque).

If an affirmative decision is made in step 106, the routine is returned. If a negative decision is made in step 106, steps 102 to 10 are executed.
5, the speed ratio ig of the gear transmission mechanism 4, the slip ratio ΔN of the torque converter 2, and the regenerative torque TM of the motor generator 3 are controlled so that the regenerative braking efficiency η is maximized.

As described above, the lock-up clutch 11 is controlled by the control of steps 102 to 106.
When any one of the states (A) to (C) is set, it is possible to control various conditions so that the regenerative braking efficiency η in that state is maximized. Further, when any of the states (A) to (C) of the lock-up clutch 11 is set by the control of steps 102 to 106, the regenerative braking efficiency η in all the states is maximized. In the state,
It is also possible to set various conditions. Furthermore,
In the above control example, the relationship between the various conditions and the regenerative braking efficiency η is obtained by the arithmetic processing. However, data obtained by mapping the relationship between the various conditions and the regenerative braking efficiency η is stored in the electronic control device 58 in advance. It is also possible to keep.

Here, the correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Step 102
Step 106 corresponds to the regenerative braking condition control means of the present invention.

As described above, according to the control example shown in FIG. 1, the gear ratio ig of the gear transmission mechanism 4 and the engagement ratio of the torque converter 2 are adjusted so that the regenerative braking efficiency η of the motor generator 3 is maximized. Slip state and motor generator 3
, And the charging efficiency η BATT for the battery 81 is controlled. Specifically, conditions including at least the engagement / slip state of torque converter 2 are controlled. Therefore, the engine output used for charging the battery 81 is suppressed as much as possible, and the fuel efficiency is improved. When the vehicle is driven by the power of the engine 1,
By releasing the lock-up clutch 11, fluctuations in engine torque can be absorbed or reduced by the torque converter 2. In other words, fuel efficiency is improved,
It is possible to achieve both the function of suppressing vibration and noise.

FIG. 8 is a flowchart showing another control example of the hybrid vehicle. First, the electronic control unit 58
Process the input signal (step 200). Next, it is determined whether the regenerative braking condition of the motor generator 3 is satisfied (step 201). The criterion of this step 201 is the same as that of step 101 described above.

If a negative determination is made in step 201, the routine returns. If an affirmative determination is made in step 201, the detected vehicle speed and accelerator opening are shifted from the release area of the lock-up clutch 11 to the area where the lock-up clutch 11 is completely engaged or the area where the slip control is performed. It is determined whether or not the switching is performed (step 202). The determination in step 202 is made based on the lock-up clutch control map shown in FIG.
If a negative determination is made in step 202, the process returns.

On the other hand, if an affirmative determination is made in step 202, the clutch 84D of the driving device 84 is engaged, and the power of the motor generator 85 is transmitted to the engine 1 so that the engine speed approaches the turbine speed. Control is performed (step 203). Then, it is determined whether or not the engine speed has reached the target value (step 204). If a negative determination is made in step 204, the process returns to step 205. Here, the target value is a value determined to be unlikely to cause a shock due to a sudden increase in the engine braking force even if the lock-up clutch 11 is slip-controlled or completely engaged. This target value is stored in the electronic control unit 58 in advance.

If an affirmative decision is made in step 204,
Control for completely engaging or slipping the disengaged lock-up clutch 11 is performed (step 20).
5) Return. Here, the correspondence between the functional means shown in FIG. 8 and the configuration of the present invention will be described. Steps 201 to 205 correspond to the rotating machine control means of the present invention.

FIG. 9 is a time chart showing the state of the system corresponding to the control example of FIG. In a state where the lock-up clutch 11 is off (disengaged),
The rotation speed of the output shaft 32 is controlled to a predetermined value, and the engine rotation speed is controlled to a predetermined value. Then, at time t1, a control signal for increasing the engine speed is output, and the engine speed is gradually increased by the power of motor generator 3. Next, at time t2, it is determined that the engine speed has reached the target value.

Thereafter, at time t3, a signal for turning on (fully engaging) the lock-up clutch 11 is output. Then, the engagement pressure of the lock-up clutch 11 is gradually increased, and the engine braking force is increased.
And the engine speed gradually increases. When the lock-up clutch 11 is completely engaged at time t4, the engine speed and the speed of the output shaft 32 are controlled to be substantially constant thereafter.

As described above, according to the control example of FIG. 8, when the lock-up clutch 11 in the disengaged state is switched to the fully engaged or slipped state during the regenerative braking of the motor generator 3, the engine speed and the input shaft are changed. 14 so as to reduce the difference from the rotation speed of the motor generator 8.
5 is controlled. Therefore, the motor generator 3
When the disengaged lock-up clutch 11 is switched to the fully engaged or slipped state during the regenerative braking, the sudden increase in the engine braking force is suppressed, and the occurrence of a shock can be avoided. The power of the motor / generator 3 can be used to perform control to reduce the difference between the engine speed and the input shaft 14 speed.

[0068]

According to the first aspect of the present invention, the regenerative braking torque of the motor / generator, the engaged / disengaged state of the direct-coupled clutch, or the speed change so that the regenerative braking efficiency of the motor / generator is in a predetermined state. Among the conditions of the gear ratio of the machine, conditions including at least the engaged / disengaged state of the direct coupling clutch are controlled. Therefore, for example, the regenerative braking efficiency of the motor generator can be improved as much as possible. Therefore, the power of the engine provided to make the motor / generator function as a generator is suppressed as much as possible, and the fuel efficiency can be improved.

According to the second aspect of the present invention, the difference between the engine speed and the speed of the second rotating member is reduced in engaging the disengaged direct-coupled clutch during regenerative braking of the motor generator. The rotating machine is controlled. Therefore, a sudden increase in the engine braking force is suppressed, and the occurrence of a shock can be avoided.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a power train control device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a hybrid vehicle to which the present invention is applied.

FIG. 3 is a skeleton diagram showing a configuration of a gear transmission mechanism and a torque converter shown in FIG. 2;

FIG. 4 is a table showing an operation state of a friction engagement device for setting each shift speed in the gear transmission mechanism shown in FIG. 3;

FIG. 5 is a block diagram showing a control system of a hybrid vehicle to which the present invention is applied.

FIG. 6 is a map applied to shift control of a gear transmission mechanism and control of a lock-up clutch during regenerative braking of a motor generator in an embodiment of the present invention.

FIG. 7 is a diagram showing motor efficiency determined by the number of revolutions of the motor generator and the regenerative braking torque in the embodiment of the present invention.

FIG. 8 is a flowchart showing another control example of the present invention.

FIG. 9 is a time chart corresponding to the control example of FIG. 8;

[Explanation of symbols]

1 ... engine, 2 ... torque converter, 3,85 ...
Motor / generator, 4 gear transmission mechanism, 7 pump impeller, 8 front cover, 10 hub
11: lock-up clutch, 14: input shaft, 5
8. Electronic control unit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Tabata 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3J053 CA03 CB14 DA06 DA12 DA26 DA30 FA03 5H115 PA12 PG04 PI16 PI22 PI29 PO17 PU10 PU22 PU24 PU25 PV09 PV23 QE10 QI04 QI09 QN03 RB08 RE02 SE04 SE06 SE08 TB01 TE02 TE03 TE07 TE08 TI01 TO12 TO21 TO23

Claims (2)

[Claims] A motor generator functioning as a generator by power input from an engine or power input from wheels; a fluid power transmission device disposed between the motor generator and the wheels; A direct-coupled clutch engaged / disengaged to switch the power transmission state between rotating members of the hydraulic power transmission device, and a transmission disposed between the hydraulic power transmission device and the wheels; In a power train control device capable of transmitting power input from the wheels to the motor generator to generate regenerative braking torque, such that the regenerative braking efficiency of the motor generator is in a predetermined state. Each condition of the regenerative braking torque of the motor / generator, the engaged / disengaged state of the direct coupling clutch, or the speed ratio of the transmission. Of the control device of the power train, characterized in that it comprises a regenerative braking condition control means for controlling the conditions including engagement and disengagement states of at least the direct-coupled clutch. 2. A first rotating member connected to the engine,
A second rotating member connected to a wheel, a fluid power transmission device for transmitting power between the first rotating member and the second rotating member, and a regenerative braking torque by power input from the wheel. A motor-generator, a direct-coupled clutch engaged / disengaged to change a power transmission state between the first rotating member and the second rotating member, and a rotating machine transmitting power to the engine A power train control device having: a regenerative braking by the motor / generator; a direct coupling clutch control means for changing an engagement / disengagement state of the direct coupling clutch; and Rotating machine control means for applying the power of the rotating machine to the engine so as to reduce the difference between the engine speed and the speed of the second rotating member. Control device for a power train, characterized in that.