JP2001112117A - Regenerative braking system for vehicles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently charge a battery by disconnecting an engine without deteriorating the restartability of the engine, and to prevent an excessive oil pressure required during shifting of a belt-type continuously variable transmission. I do. SOLUTION: During traveling in a direct connection mode in which clutches C1 and C2 are engaged, an accelerator is turned off and the motor generator 1 is turned off.
In the regenerative control of the clutch 6, when the engine water temperature satisfies a predetermined engine disconnection condition such as a predetermined value or more, the clutch C
2 is released to disconnect the engine 14 from the power transmission path. Further, in consideration of the required oil pressure of the belt-type continuously variable transmission 12, an operating point (rotational speed) at the time of regenerative control of the motor generator 16 is obtained according to a map set so that the required oil pressure does not become excessive. The speed of the belt-type continuously variable transmission 12 is controlled so as to be rotationally driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking device for charging a battery and applying a braking force to a vehicle by rotating a generator with kinetic energy of the vehicle.

[0002]

2. Description of the Related Art (a) An engine that generates power by burning fuel, (b) a motor generator, and (c) the engine,
(D) connecting, disconnecting, or connecting a predetermined one of the rotating elements to the electric motor, and a gear type combining and distributing device that combines and distributes power between the electric motor and the output member. A hybrid drive device having a friction engagement clutch or brake is known. JP-A-9-374
The device described in Japanese Patent Publication No. 11 is an example of this, in which the operating state of a clutch or a brake is switched so that the motor generator is rotated by the kinetic energy of the vehicle to charge the battery and apply a braking force to the vehicle. The regenerative braking mode is established. Further, two types of regenerative braking modes are described, namely, a case where the engine is separated and a braking force is applied only by a motor generator, and a case where an engine brake is used together by rotating the engine.

[0003]

However, such a conventional regenerative braking device does not disclose any conditions for disconnecting the engine. For example, when the engine water temperature or the transmission oil temperature is low, the engine is disconnected and stopped. When,
Power performance and emissions could be impaired due to worse engine restartability.

[0004] When a belt-type continuously variable transmission is provided,
The required oil pressure varies depending on the gear ratio. For example, when the required oil pressure is high at a low vehicle speed where the gear ratio is large, a shift is performed at a large gear speed so that the generator is rotationally driven at a predetermined operating point at the low vehicle speed. In such a case, there is a possibility that the shift hydraulic pressure required for shifting becomes excessively large, fuel efficiency is deteriorated due to an increase in pump load, and belt slippage occurs due to insufficient hydraulic pressure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to charge a battery efficiently by disconnecting an engine without deteriorating the restartability of the engine. Another object of the present invention is to prevent a required hydraulic pressure from being excessively increased due to a shift when a belt-type continuously variable transmission is provided.

[0006]

In order to achieve the above object, the first invention has (a) an engine which operates by combustion of fuel as a driving power source, and (b) a kinetic energy of a vehicle. When the generator is rotationally driven, the regenerative braking of the vehicle is performed by applying regenerative braking force to the vehicle and charging the battery by the regenerative control of the generator. It is characterized in that it has an engine disconnecting means for determining whether or not the disconnection condition is satisfied, and disconnecting the engine from the power transmission path when the engine disconnection condition is satisfied.

According to a second aspect of the present invention, in the regenerative braking system for a vehicle according to the first aspect, (a) the generator is connected to wheels via a transmission, and (b) the engine is separated by the engine disconnecting means. Operating point setting means for separately setting an operating point of the generator at the time of the regenerative control, and (c) a shift control for shifting the transmission so that the generator is rotationally driven at the operating point. And control means.

According to a third invention, there is provided the regenerative braking device for a vehicle according to the second invention, wherein (a) the transmission is a hydraulic stepless transmission;
(b) The operating point setting means sets an operating point of the generator in consideration of a required hydraulic pressure of the hydraulic continuously variable transmission.

According to a fourth aspect of the present invention, when the generator is rotationally driven by the kinetic energy of the vehicle via the hydraulic continuously variable transmission, regenerative control of the generator applies regenerative braking force to the vehicle and charges the battery. Operating point setting means for setting an operating point of the generator in consideration of a required hydraulic pressure of the hydraulic stepless transmission during the regenerative control; And a shift control means for shifting the hydraulic continuously variable transmission so that the generator is driven to rotate.

[0010]

In the regenerative braking system for a vehicle according to the first invention, it is determined whether or not the state of the vehicle satisfies a predetermined engine disconnection condition during regenerative control. Because it is separated from the power transmission path, for example, when the restartability of the engine deteriorates, the engine disconnection condition is set so that the engine is not disconnected, so that the power due to the deterioration of the engine restartability is reduced. The battery can be efficiently charged by disconnecting the engine while avoiding a decrease in performance and emission, and both the restartability of the engine and the regenerative efficiency can be achieved.

In the second invention, the operating point of the generator is set separately depending on whether or not the engine has been disconnected by the engine separating means, and the transmission is controlled so that the generator is rotationally driven at the operating point. In addition, appropriate charging control can be performed according to the presence or absence of the engine. For example, when the engine is disconnected, the operating point of the generator is set to the high rotation side, thereby avoiding an increase in oil pressure during shifting due to the inertia of the engine, etc., and driving the generator to rotate at the high efficiency high rotation side to efficiently use the battery. Can be charged.

In the third aspect, the operating point of the generator is set in consideration of the required hydraulic pressure of the hydraulic continuously variable transmission.
At the time of shifting to rotate the generator at the operating point,
It is possible to prevent the required oil pressure from becoming excessive and the fuel efficiency from being deteriorated due to an increase in the pump load, or the oil pressure from being insufficient.
For example, if the required oil pressure increases as the gear ratio increases,
On the high vehicle speed side where the required hydraulic pressure is small and the transmission ratio is small, the transmission speed can be relatively high, so the operating point can be set arbitrarily according to the generator efficiency, and charging can be performed efficiently. On the other hand, on the low vehicle speed side where the gear ratio where the required oil pressure is large and the gear ratio is large, the operating point is set so that the gear speed is reduced, so that the required oil pressure can be prevented from becoming excessive. The same applies to the fourth invention.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The engine disconnection conditions of the first invention include, for example, that the engine water temperature is equal to or higher than a predetermined value and that the oil temperature of the transmission is equal to or higher than a predetermined value. Although it is predetermined so that the startability is not impaired, the engine disconnection condition can be set using another vehicle state.

As the transmission of the second invention, a hydraulic continuously variable transmission such as a belt type or a toroidal type is suitably used as in the third and fourth inventions. It is also possible to use a gear transmission.

As the generator, a motor generator capable of obtaining both functions of an electric motor and a generator is preferably used, but a motor generator having no function of an electric motor may be used. An electric motor or a motor generator may be provided separately from the generator.

The operating point setting means according to the third and fourth aspects of the present invention comprises:
For example, the operating point is set on the optimum efficiency line of the motor generator, and the efficiency is generally higher on the higher rotation side even on the optimum efficiency line, so the required hydraulic pressure of the hydraulic continuously variable transmission exceeds the allowable range. It is configured to set the operating point as high as possible within the range that does not exist.

On the other hand, the gear ratio γ (=
A belt-type continuously variable transmission in which the input shaft rotation speed / output shaft rotation speed) and the belt tension are controlled requires different hydraulic pressures depending on the gear ratio γ, and the operating point of the generator (the input shaft of the transmission is determined by the rotation speed of the generator). The greater the difference between the target gear ratio γ ^* determined according to the rotational speed) and the current gear ratio γ, and the lower the vehicle speed, the greater the gear speed and the greater the shift hydraulic pressure required for gear shifting. Therefore, on the high vehicle speed side where the original required hydraulic pressure is small and the gear ratio γ is small,
The gear ratio γ can be largely changed at a large gear speed, and the operating point of the generator can be set to a high-efficiency, high-speed rotation to greatly downshift the gear ratio γ to an increasing side, while the required hydraulic pressure is large. On the low vehicle speed side where the gear ratio γ is large, the operating point of the generator is set to a relatively low speed so that the change width of the gear ratio γ, in other words, the gear speed becomes small, and the required oil pressure accompanying the shift (downshift) increases. Is desirably reduced. In other words, the operating point setting means sets a predetermined arithmetic expression such that the operating point (rotational speed) of the generator becomes lower toward the lower vehicle speed side so that the required oil pressure of the continuously variable transmission does not become excessive. According to setting data such as a map, the driving point can be set according to the vehicle speed. The operating point setting means is appropriately determined according to the hydraulic characteristics of the hydraulic continuously variable transmission.

The present invention is suitably applied to various hybrid vehicles such as a series type and a parallel type equipped with an engine and a motor generator for generating power by fuel combustion as a power source for traveling. For example, (a) an engine that generates power by burning fuel, (b) a motor generator, and (c) the engine is connected to a first rotating element and the motor generator is connected to a second rotating element. A gear-type combining and distributing device such as a planetary gear device;
(d) a transmission that changes the power output from the combined distribution device and transmits the power to the drive wheels, and (e) a friction engagement device that disconnects the engine from a power transmission path. May also be applied. In addition, the first invention to the third invention
The invention only needs to include at least an engine as a power source for traveling, and the fourth invention may be an electric vehicle without an engine.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a hybrid drive device 10 to which the present invention is applied. FIG. 2 is a skeleton diagram including a transmission 12, and the hybrid drive device 10 generates power by fuel combustion. The engine includes an engine 14, a motor generator 16 used as an electric motor and a generator, and a double pinion type planetary gear device 18. The engine 14 is connected to the sun gear 18s of the planetary gear set 18, and the carrier 1
The motor generator 16 is connected to 8c, and the ring gear 18r is connected to the case 20 via the first brake B1. The carrier 18c is the first
The ring gear 18r is connected to the input shaft 22 via the second clutch C2, and is connected to the input shaft 22 of the transmission 12 via the clutch C1. Planetary gear 1
8 is a combining and distributing device, a sun gear 18s is a first rotating element, a carrier 18c is a second rotating element, and a ring gear 18
r corresponds to a third rotating element. The input shaft 22 of the transmission 12 corresponds to an output member.

Each of the clutches C1, C2 and the first brake B1 is a wet-type, multi-plate type hydraulic frictional engagement device that is frictionally engaged by a hydraulic actuator, and is frictionally engaged by hydraulic oil supplied from a hydraulic control circuit 24. It is adapted to be combined. FIG. 3 is a diagram showing a main part of the hydraulic control circuit 24. The original pressure PC generated by the electric hydraulic pressure generating device 26 including the electric pump is connected to the manual valve 2.
The power is supplied to the clutches C1 and C2 and the brake B1 via the control lever 8 in accordance with the operation range of the shift lever 30 (see FIG. 1). The shift lever 30 is a shift operation member operated by the driver. In this embodiment, the shift lever 30 is selectively operated in five ranges of “B”, “D”, “N”, “R”, and “P”. The manual valve 28 is connected to the shift lever 30 via a cable or a link.
, And can be mechanically switched in accordance with the operation of the shift lever 30.

The "B" range indicates that the transmission 12
The operation range in which a relatively large power source brake is generated due to a downshift or the like, and the "D" range is an operation range in which the vehicle travels forward. Is supplied. The original pressure PC is supplied to the first clutch C1 via the shuttle valve 31. "N"
The range is an operation range that cuts off the transmission of power from the power source, and the “R” range is an operation range that runs backward, and “P”
The range is an operation range in which power transmission from the power source is cut off and the rotation of the drive wheels is mechanically prevented by a parking lock device (not shown). In these operation ranges, the original pressure is supplied from the output port 28b to the first brake B1. A PC is provided. Original pressure PC output from output port 28b
Is also input to the return port 28c. In the "R" range, the original pressure PC is supplied from the shuttle valve 31 to the first clutch C1 from the return port 28c via the output port 28d.

The clutches C1, C2 and the brake B1
Are provided with control valves 32, 34 and 36, respectively, so that the oil pressures P _C1 , P _C2 and P _B1 thereof are controlled. ON for hydraulic pressure P _C1 of clutch C1
The pressure is regulated by the -OFF valve 38, and the hydraulic pressures P _C2 and P _B1 of the clutch C2 and the brake B1 are regulated by the linear solenoid valve 40.

Each running mode shown in FIG. 4 is established according to the operating states of the clutches C1, C2 and the brake B1. That is, in the "B" range or the "D" range, any one of the "ETC mode", the "direct connection mode", and the "motor running mode (forward)" is established. In the "ETC mode", the second clutch C2 is engaged. The first clutch C1 and the first brake B
When the vehicle 1 is open, the engine 14 and the motor generator 16 are operated together to make the vehicle travel forward.
In the “direct connection mode”, the engine 1 is engaged with the clutches C1 and C2 engaged and the first brake B1 released.
4 is operated to move the vehicle forward. In the “motor running mode (forward)”, the motor generator 16 is operated to cause the vehicle to run forward with the first clutch C1 engaged and the second clutch C2 and the first brake B1 released. The “ETC mode” is an electric torque converter mode corresponding to an engine / motor running mode, and the “direct connection mode” corresponds to an engine direct connection mode.

FIG. 5 is an alignment chart showing the operating state of the planetary gear device 18 in the forward mode, where "S" indicates a sun gear 18s, "R" indicates a ring gear 18r, and "C" indicates a carrier 18c. , Their spacing is the gear ratio ρ
(= Number of teeth of sun gear 18s / number of teeth of ring gear 18r)
Is determined by Specifically, assuming that the interval between “S” and “C” is 1, the interval between “R” and “C” becomes ρ, and in this embodiment, ρ is about 0.6. Further, the torque ratio in the ETC mode of (a) is engine torque Te: CVT input shaft torque Tin: motor torque Tm = ρ: 1: 1−ρ, and the motor torque Tm can be smaller than the engine torque Te. In a steady state, the torque obtained by adding the motor torque Tm and the engine torque Te is CV
It becomes T input shaft torque Tin. CVT means a continuously variable transmission. In this embodiment, a belt-type continuously variable transmission is provided as the transmission 12.

Returning to FIG. 4, "N" range or "P"
In the range, either “neutral” or “charge / eng start mode” is established, and “neutral”
Then, all of the clutches C1, C2 and the first brake B1 are released. In the “charging / Eng start mode”, the clutches C1 and C2 are released, the first brake B1 is engaged, the motor generator 16 is rotated in the reverse direction to start the engine 14, and the planetary gear device 1
The motor 42 is rotated and driven via the motor 8, the regenerative control of the motor generator 16 is performed to generate electric power, and the battery 42 (see FIG. 1) is charged.

In the "R" range, a "motor running mode (reverse)" or a "friction running mode" is established. In the "motor running mode (reverse)", the first clutch C1 is engaged and the second clutch is engaged. With C2 and the first brake B1 released, the motor generator 16 is operated in the reverse rotation direction to cause the vehicle to travel backward.
In the "friction running mode", the first clutch C1 is engaged and the second clutch C2 is released.
By operating the motor generator 16 in the reverse rotation direction to cause the vehicle to travel backward, the engine 14 is operated and the first brake B1 is slip-engaged in a state where the ring gear 18r is rotated in the forward direction. Is to apply a reverse assist force to the input shaft 22.

The transmission 12 is a belt-type continuously variable transmission.
From the output shaft 44 via a counter gear 46, the differential 4
Power is transmitted to the ring gear 50 of the differential gear 8 and the differential gear 4
8, the power is distributed to the left and right drive wheels 52.

The hybrid drive device 10 of the present embodiment is
It is controlled by the HVECU 60 shown in FIG. HVECU 60 includes a CPU, a RAM, and a ROM.
And the like while using the temporary storage function of the RAM.
By executing signal processing according to a program stored in the OM in advance, the electronic throttle ECU 62, the engine ECU 64, the M / GECU 66, the T / MECU 68,
It controls the ON-OFF valve 38, the linear solenoid valve 40 of the hydraulic control circuit 24, the starter 70 of the engine 14, and the like. The electronic throttle ECU 62 controls opening and closing of an electronic throttle valve 72 of the engine 14.
The CU 64 controls the engine output based on the fuel injection amount of the engine 14, the variable valve timing mechanism, the ignition timing, and the like, and the M / GECU 66 controls the power running torque, the regenerative braking torque, and the like of the motor generator 16 via the inverter 74. The T / MECU 68 determines the transmission ratio γ of the transmission 12 (= input shaft rotation speed Nin / output shaft rotation speed Nou).
t) and belt tension are controlled. The hydraulic pressure control circuit 24 includes a circuit for controlling the transmission ratio γ and the belt tension of the transmission 12, and the required hydraulic pressure is generated by the electric hydraulic pressure generator 26. The starter 70 is an electric motor that cranks the engine 14 by meshing a pinion provided on a motor shaft with a ring gear provided on a flywheel or the like of the engine 14.

The HVECU 60 supplies a signal indicating the operation amount θac of an accelerator pedal 78 as an accelerator operation member from the accelerator operation amount sensor 76 and the signal O when the accelerator is off.
An idle contact signal of N is supplied, and a signal indicating the operation range (shift position) of the shift lever 30 is supplied from the shift position sensor 80. From the brake ECU 90, a brake ON / OFF signal indicating whether or not the brake pedal is depressed,
A brake oil pressure or a pedal depression force that indicates a braking force is supplied. Further, from the engine rotation speed sensor 82, the motor rotation speed sensor 84, the input shaft rotation speed sensor 86, and the output shaft rotation speed sensor 88, respectively, the engine rotation speed (rotation speed) Ne, the motor rotation speed (rotation speed) Nm, the input shaft Rotation speed (rotation speed of input shaft 22) Nin, output shaft rotation speed (rotation speed of output shaft 44) N
out is supplied. The output shaft rotation speed Nout corresponds to the vehicle speed V. In addition, various signals indicating the operating state, such as the state of charge SOC of the battery 42, are supplied. The state of charge SOC may be simply a battery voltage, or may be obtained by successively integrating the amount of charge and discharge.

The HVECU 60 basically has the functions shown in FIG. 6, and is adapted to execute the running mode shown in FIG. The ETC mode control means 100 in FIG. 6 implements the “ETC mode”, the direct connection mode control means 102 implements the “direct connection mode”, and the motor forward means 104 implements the “motor traveling mode (forward)”. The charging control means 106 implements a “charging / Eng start mode”, the motor reversing means 108 implements a “motor traveling mode (reverse)”, and the engine assist reversing means 110 performs “friction traveling”. The mode is implemented, and the ETC mode control means 100 and the direct connection mode control means 102 constitute an engine forward means 112. The mode determination means 114 determines the travel mode based on the accelerator operation amount θac, the vehicle speed V (output shaft rotation speed Nout), the stored power SOC, the shift position of the shift lever 30, and the like, and operates in the determined travel mode. The above-mentioned means are switched so that the operation is performed.

In the "direct connection mode" by the direct connection mode control means 102, the accelerator operation is released (accelerator OFF) while the shift lever 30 is operated to the "B" range and the vehicle is running at a predetermined vehicle speed or higher. When the brake pedal is depressed (ON) or the like, regenerative control of the motor generator 16 that is rotationally driven by the kinetic energy of the vehicle applies regenerative braking force to the vehicle and charges the battery 42. ing. That is, in this embodiment, the direct connection mode control means 10
2, a regenerative braking device is configured. In addition,
When the shift lever 30 is in the “D” range, the same regenerative control is performed as necessary.

FIG. 7 is a flowchart for explaining the operation of the regenerative control executed by the direct connection mode control means 102 when the idle contact signal is turned on or the brake pedal is turned on. It is repeatedly executed in time. During the regeneration control, the fuel injection to the engine 14 is stopped.

In step S1 of FIG. 7, it is determined whether or not traveling by only the motor generator 16 is possible, in other words, whether or not the engine disconnection condition that the engine 14 can be separated and stopped in rotation is satisfied. The engine disconnection conditions include, for example, that the cooling water temperature of the engine 14 is equal to or higher than a predetermined value, and that the oil temperature of the transmission 12 is equal to or higher than a predetermined value. It is predetermined so as not to occur.
The cooling water temperature of the engine 14 and the oil temperature of the transmission 12 are detected by temperature sensors, respectively.
/ MECU 68 to the HVECU 60.

If the engine disconnection condition is satisfied, the second clutch C2 is released by the linear solenoid valve 40 in step S3, whereby the engine 1 is disconnected.
4 is disconnected from the power transmission path. As a result, the rotation of the engine 14 is stopped by its own rotational resistance such as a pumping action and friction. In step S4, the operating point (target rotational speed Nm ^* ) of the motor generator 16 is determined according to the regeneration request torque Trq, and the belt-type continuously variable transmission 12 is driven so that the motor generator 16 is driven to rotate at the operating point. Gear shift control. Also in step S2, in which the regenerative control is performed while the engine 14 is being driven without being disconnected, the operating point (the target rotational speed Nm ^* ) of the motor generator 16 is similarly determined in accordance with the required regenerative torque Trq. Motor generator 16 at operating point
The transmission of the belt-type continuously variable transmission 12 is controlled so that the transmission is rotationally driven.

FIG. 8 is a flowchart specifically illustrating the control contents of steps S2 and S4.
Then, the regenerative request torque Trq is calculated according to the vehicle speed V.
The driver's required regenerative torque Trq generally increases as the vehicle speed V increases, and is obtained from a predetermined data map, for example, as shown in FIG. FIG. 9 shows the case where the accelerator is off and the brake is off.
From the output shaft 44 side, from which the gear ratio γ
In consideration of the input shaft 22 side (motor generator 16 side)
And perform regenerative control. At this time, by converting the efficiency using the efficiency map of the belt-type continuously variable transmission 12,
The deceleration can be controlled with higher accuracy.

In step R2, the required regeneration torque T
An operating point of the motor generator 16, that is, a target rotation speed Nm ^* is calculated from rq. The calculation of the operating point is performed using, for example, a predetermined data map as shown in FIG. 10, and when the engine 14 indicated by a solid line is disconnected (step S4), the engine 14 indicated by an alternate long and short dash line is rotated. (Step S2). If the engine 14 is disconnected,
, The shift hydraulic pressure required for downshifting the belt-type continuously variable transmission 12 to increase the gear ratio γ and increasing the input shaft rotation speed Nin decreases, and the operating point increases accordingly. It can be set to a value.

In setting the operating point, it is basically determined to operate on the optimum efficiency line L1 based on the efficiency map of the motor generator 16 shown in FIG. Since the efficiency is higher on the higher rotation side, it is desirable to set the operating point on the higher rotation side as much as possible within a range where the required oil pressure of the belt-type continuously variable transmission 12 does not exceed the allowable range.

On the other hand, the belt type continuously variable transmission 12 of this embodiment
Is a bandone type in which the gear ratio and the belt tension are controlled by the hydraulic cylinder, and the belt tension is controlled by the hydraulic pressure of the driven hydraulic cylinder. The required hydraulic pressure is the gear ratio as shown in FIG. The larger the value of γ, the larger the required hydraulic pressure becomes. Further, the larger the difference between the target speed ratio γ ^* , which is determined according to the operating point of the motor generator 16, that is, the input shaft rotation speed Nin, and the current speed ratio γ, the higher the speed speed and the higher the required oil pressure for the speed change. . Therefore, on the high vehicle speed side where the original required hydraulic pressure is small and the gear ratio γ is small, the gear ratio γ can be largely changed at a large gear speed, and the operating point of the motor generator 16 is set to high efficiency and high rotation. While the gear ratio γ can be largely changed to the increasing side, on the low vehicle speed side where the required hydraulic pressure is large and the gear ratio γ is large,
It is necessary to set the operating point of the motor generator 16 to a relatively low rotation so that the change width of the gear ratio γ, that is, the shift speed becomes small, and to reduce the increase in the required oil pressure accompanying the shift.

The map shown in FIG. 10 is set such that the required oil pressure of the belt-type continuously variable transmission 16 is not excessively increased from such a viewpoint. Sixteen operating points are set so that the rotation speed is low. The map of FIG. 10 is the same regardless of whether the brake pedal is depressed or not, the same operating point (target rotational speed Nm ^* ) is maintained, and only the regenerative torque of the motor generator 16 changes according to the increase or decrease of the braking force. Can be increased or decreased.

Returning to FIG. 8, in step R3, the motor
When the generator 16 is at the operating point (the target rotation speed Nm^*) Rotate
The target shift of the belt-type continuously variable transmission 12 is
Ratio γ ^*Is calculated. Specifically, the target rotation speed Nm^*To
By dividing by the actual output shaft rotation speed Nout
Desired. Then, in step R4, the belt-type stepless
The speed ratio γ of the transmission 12 is equal to the target speed ratio γ^*Change to become
A speed change command is output to the T / MECU 68, and
Therefore, the shift control is performed.

The solid line in FIG. 13 indicates the shift speed of the belt-type continuously variable transmission 12 when the operating point of the motor generator 16 is obtained according to the flowchart of FIG. , And the rotation speed Nin
7 is an example of a time chart showing changes in (= motor rotation speed Nm) and Nout. The dashed line in FIG. 13 is a conventional example.
The shift speed is increasing with a decrease in the vehicle speed V (a decrease in the output shaft rotation speed Nout), and the gear ratio γ, which originally requires a large hydraulic pressure, is a low vehicle speed. The pump load may be out of tolerance or belt slippage may occur.

Returning to FIG. 7, in step S5, the maximum allowable hydraulic pressure of the electric hydraulic pressure generator 26 for generating the hydraulic pressure required for the belt-type continuously variable transmission 12 and the actual value of the belt-type continuously variable transmission 12 are determined. Calculate the shift speed. The allowable maximum generated oil pressure is calculated from the torque characteristics of the oil pump motor, the volume efficiency of the oil pump, and the friction (a function of the oil temperature) as shown in FIG. 14, for example. ) And control with a map. In step S6, the regenerative torque limit value of the motor generator 16 that can perform regenerative control while avoiding belt slippage of the belt-type continuously variable transmission 12 based on the allowable maximum generated hydraulic pressure and the actual shift speed. (Maximum value) Trg is calculated. In step S7, the regenerative request torque Trq is compared with the regenerative torque limit value Trg.
If rq> Trg, in step S8, the regenerative torque limit value T
The regenerative control of the motor generator 16 is executed by rg, and Trq
If .ltoreq.Trg, the regenerative control of the motor generator 16 is executed with the required regenerative torque Trq in step S9. As a result, the regenerative control of the motor generator 16 is performed while reliably preventing the belt of the belt-type continuously variable transmission 12 from slipping.

In this embodiment, it is determined whether or not a predetermined engine disconnection condition is satisfied so that the restartability of the engine 14 is not impaired. The two clutches C2 are released to disconnect the engine 14 from the power transmission path.
, The battery 42 can be charged efficiently, and both the restartability of the engine 14 and the regeneration efficiency can be achieved.

The operating points during the regenerative control of the motor generator 16 are separately obtained according to whether or not the engine 14 has been disconnected using two types of preset maps as shown in FIG. Belt-type continuously variable transmission 1 so that the motor generator 16 is rotationally driven at a point.
Since the speed of the second gear is controlled, appropriate charging control can be performed according to the presence or absence of the engine 14. That is, when the engine is disconnected, the operating point of the motor generator 16 is set to the high rotation side, and the motor generator 16 is prevented from increasing due to the inertia of the engine 14 during shifting.
Can be rotated on the high-efficiency, high-rotation side to charge the battery 42 efficiently.

The map for obtaining the operating points in FIG. 10 is set in consideration of the required oil pressure of the belt-type continuously variable transmission 12 so that the required oil pressure is not excessive.
At the time of gear shifting for rotating and driving the motor generator 16 at the operating point, it is possible to prevent the required oil pressure from becoming excessive and the pump load from increasing, thereby deteriorating fuel economy and causing the oil pressure to be insufficient to cause belt slippage. Also, the gear ratio γ where the required hydraulic pressure is small and the speed ratio γ is small, that is, the regenerative required torque T
On the side where rq is large, the operating point of the motor generator 16 is set to the high rotation side, and the speed of the belt-type continuously variable transmission 12 is controlled so as to rotate at the high rotation. It can be performed.

Further, the map for obtaining the operating point in FIG.
Since the same operating point (target rotation speed Nm ^* ) is maintained regardless of whether or not the brake pedal is depressed, the regenerative torque of the motor generator 16 is merely increased or decreased in accordance with the increase or decrease in the braking force. A change in the target rotation speed Nm ^* due to a change in the depression of the pedal, and a shift in the belt-type continuously variable transmission 12 are prevented, and the braking force is stabilized.

In a series of signal processing performed by the direct connection mode control means 102, steps S1 and S1 shown in FIG.
3 constitutes an engine disconnecting means together with the second clutch C2 and the linear solenoid valve 40. Of the execution contents of steps S2 and S4, the execution portion of steps R1 and R2 in FIG. The part that functions as setting means and executes steps R3 and R4 constitutes a transmission control means together with the T / MECU 68.

Although the embodiment of the present invention has been described in detail with reference to the drawings, this is merely an embodiment of the present invention, and the present invention is not limited to various modifications and alterations based on the knowledge of those skilled in the art.
It can be implemented in an improved manner.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a hybrid drive device to which the present invention is applied.

FIG. 2 is a skeleton view showing a power transmission system of the hybrid drive device of FIG. 1;

FIG. 3 is a circuit diagram showing a part of the hydraulic control circuit of FIG. 1;

FIG. 4 is a diagram for explaining a relationship between some traveling modes established in the hybrid drive device of FIG. 1 and operating states of a clutch and a brake.

FIG. 5 is a collinear chart showing a relationship between rotation speeds of respective rotating elements of the planetary gear device in the ETC mode, the direct connection mode, and the motor traveling mode (forward) in FIG.

FIG. 6 is a block diagram showing some functions of the HVECU of FIG. 1;

FIG. 7 is a flowchart illustrating an operation when the regenerative control of the motor generator is performed in the direct connection mode.

FIG. 8 is a flowchart illustrating specific contents of steps S2 and S4 in FIG. 7;

FIG. 9 is a diagram illustrating an example of a data map used for obtaining a regeneration request torque Trq in step R1 of FIG. 8;

FIG. 10 is a diagram illustrating an example of a data map used for obtaining an operating point of a motor generator in step R2 of FIG.

FIG. 11 is a diagram illustrating an example of an optimum efficiency line of a motor generator.

FIG. 12 is a diagram illustrating an example of a correlation between a gear ratio of a belt-type continuously variable transmission and a required oil pressure.

FIG. 13 is an example of a time chart showing a change in the operation state of each unit when the regenerative control is performed according to the flowchart of FIG. 7;

FIG. 14 is a diagram illustrating a method of obtaining an allowable maximum generated hydraulic pressure in step S5 of FIG. 7;

[Explanation of symbols]

10: Hybrid drive unit 12: Belt-type continuously variable transmission 14: Engine 16: Motor generator (generator) 40: Linear solenoid valve (engine disconnecting means) 42: Battery 60: HVE
CU 68: T / MECU (transmission control means) 10
2: Direct connection mode control means (regenerative braking device) C2: Second clutch (engine disconnection means) Steps S1, S3: Engine disconnection means Step R1, R2: Operating point setting means Step R3, R4: Shift control means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 9/00 F16H 9/00 E 61/02 61/02 // B60K 6/02 B60K 9/00 E ( 72) Inventor Kazumi Hoshiya 1 Toyota Town, Toyota City, Aichi Prefecture F-term in Toyota Motor Corporation (reference) 3D041 AA28 AB01 AC07 AC20 AD00 AD02 AD14 AD18 AD30 AD37 AD41 AD51 AE00 AE14 AE31 3G093 AA06 AA07 AA16 BA00 CB07 DA01 DA05 DA06 DB00 DB01 DB05 DB09 DB10 DB11 DB15 EB02 EB03 EB09 EC04 FA10 FA11 5H115 PA12 PG04 PI16 PU01 PU25 PU29 QE10 QE13 QI04 QN03 QN06 RB08 RE01 RE05 SE04 SE05 SE08 SJ12 TB01 TE02 TE08 TI01 TO21 TO23 TO30

Claims (4)

[Claims] An engine that operates by burning fuel as a power source for traveling, and when a generator is rotationally driven by kinetic energy of the vehicle, regenerative control of the generator applies a regenerative braking force to the vehicle. A regenerative braking device for a vehicle, which recharges a battery together with the battery, determines whether a state of the vehicle satisfies a predetermined engine disconnection condition during the regenerative control, and, if the engine disconnection condition is satisfied, powers the engine. A regenerative braking device for a vehicle, comprising: engine disconnecting means for separating from a transmission path. 2. The generator is connected to wheels via a transmission, and separately sets an operating point of the generator during the regenerative control depending on whether the engine is disconnected by the engine disconnecting means. The regenerative braking device for a vehicle according to claim 1, further comprising: an operating point setting unit; and a shift control unit that controls a shift of the transmission so that the generator is rotationally driven at the operating point. 3. The transmission is a hydraulic continuously variable transmission, and the operating point setting means sets an operating point of the generator in consideration of a required hydraulic pressure of the hydraulic continuously variable transmission. The regenerative braking device for a vehicle according to claim 2, wherein: 4. A regenerative vehicle for recharging a battery while applying regenerative braking force to the vehicle by regenerative control of the generator when the generator is rotationally driven through a hydraulic continuously variable transmission by kinetic energy of the vehicle. Operating point setting means for setting an operating point of the generator in consideration of a required hydraulic pressure of the hydraulic continuously variable transmission during the regenerative control, wherein the generator is rotationally driven at the operating point; A regenerative braking device for a vehicle, comprising: a shift control unit that controls a shift of the hydraulic continuously variable transmission.