JP3826637B2 - Vehicle regenerative braking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a regenerative braking device that charges a battery by rotating a generator with kinetic energy of a vehicle and applies a braking force to the vehicle.
[0002]
[Prior art]
(a) an engine that generates power by burning fuel, (b) a motor generator, and (c) a gear-type combining / distributing device that combines and distributes power among the engine, the electric motor, and an output member. (D) There is known a hybrid drive device having a friction engagement clutch and a brake for connecting and disconnecting a predetermined one of the rotating elements and connecting to a case. The device described in Japanese Patent Laid-Open No. 9-37411 is one example, and by switching the operating state of the clutch and the brake, the motor generator is rotated by the kinetic energy of the vehicle to charge the battery and control the vehicle. A regenerative braking mode in which power is applied is established. Also, there are two types of regenerative braking modes: a case where the engine is disconnected and a braking force is applied only by the motor generator, and a case where the engine brake is used together by rotating the engine.
[0003]
[Problems to be solved by the invention]
However, the conventional regenerative braking device does not describe any engine disconnection conditions. For example, if the engine is disconnected and stopped when the engine water temperature or the transmission oil temperature is low, the restartability of the engine deteriorates. As a result, power performance and emissions may be impaired.
[0004]
Also, when a belt-type continuously variable transmission is provided, the required hydraulic pressure varies depending on the gear ratio. For example, when the required hydraulic pressure is high at a low vehicle speed with a large gear ratio, the generator is driven to rotate at a predetermined operating point at the low vehicle speed. If shifting is performed at a large shifting speed as described above, the shifting hydraulic pressure required for shifting may become excessive, and fuel consumption may deteriorate due to an increase in pump load, or belt slippage may occur due to insufficient hydraulic pressure. there were.
[0005]
The present invention has been made against the background of the above circumstances, and the object of the present invention is to allow the battery to be efficiently charged by separating the engine without causing deterioration of the restartability of the engine, and the belt type. In the case of having a continuously variable transmission, it is to prevent the necessary hydraulic pressure from becoming excessive with the shift.
[0006]
[Means for Solving the Problems]
  In order to achieve this object, the first invention has (a) an engine that operates by combustion of fuel as a driving power source, and (b) when the generator is driven to rotate by the kinetic energy of the vehicle. In a regenerative braking device for a vehicle that applies regenerative braking force to the vehicle by regenerative control of the generator and charges the battery, (c)While the generator is connected to the wheels via a transmission, (d)An engine disconnecting means for determining whether or not a vehicle condition satisfies a predetermined engine disconnection condition during the regenerative control, and disconnecting the engine from the power transmission path when the engine disconnection condition is satisfiedWhen, (e) Depending on whether or not the engine is disconnected by the engine disconnecting means, operating point setting means for separately setting the operating point of the generator during the regenerative control, and (f) Shift control means for controlling the shift of the transmission so that the generator is rotationally driven at the operating point.It is characterized by that.
[0008]
  First2Invention1In the regenerative braking device for a vehicle according to the invention, (a) the transmission is a hydraulic continuously variable transmission, and (b) the operating point setting means takes into account the required hydraulic pressure of the hydraulic continuously variable transmission. The operation point is set.
[0010]
【The invention's effect】
In the regenerative braking device for a vehicle according to the first aspect of the invention, it is determined whether or not the state of the vehicle satisfies a predetermined engine disconnection condition during regenerative control, and the engine is disconnected from the power transmission path when the engine disconnection condition is satisfied. Therefore, for example, when engine restartability deteriorates, by setting engine disconnection conditions so that engine disconnection is not performed, power performance and emissions decrease due to deterioration of engine restartability It is possible to charge the battery efficiently by disconnecting the engine while avoiding the above, and it is possible to achieve both engine restartability and regeneration efficiency.
[0011]
  Also,The operating point of the generator is set separately depending on whether or not the engine is disconnected by the engine disconnecting means, and the transmission is shift-controlled so that the generator is driven to rotate at that operating point. Charge control can be performed. For example, when the engine is disconnected, the operating point of the generator is set to the high rotation side, so that the generator is rotated on the high rotation side with high efficiency while avoiding an increase in hydraulic pressure during shifting due to the inertia of the engine. Can be charged.
[0012]
  First2In the invention, since the operating point of the generator is set in consideration of the required hydraulic pressure of the hydraulic continuously variable transmission, the required hydraulic pressure becomes excessive and the pump load increases at the time of shifting for rotationally driving the generator at the operating point. It is possible to prevent the fuel consumption from deteriorating and the hydraulic pressure from becoming insufficient. For example, if the required oil pressure increases as the gear ratio increases, the operating speed can be set arbitrarily according to the efficiency of the generator because the gear speed can be relatively high on the high vehicle speed side where the gear ratio is small and the gear ratio is small. The required hydraulic pressure is excessively increased by setting the operating point so that the shift speed is reduced on the low vehicle speed side where the required gear ratio is large and the gear ratio is large. Can be avoidedThe
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The engine disconnection condition of the first aspect of the invention may be that the restartability of the engine is impaired even when the engine is stopped, for example, the engine water temperature is a predetermined value or more, or the transmission oil temperature is a predetermined value or more. However, it is also possible to set the engine disconnection condition using another vehicle state.
[0014]
  StrangeAs a speed machineThe secondAs in the invention, a belt-type or toroidal-type hydraulic continuously variable transmission is preferably used, but a stepped transmission using a planetary gear device or the like can also be used.
[0015]
As the generator, a motor generator capable of obtaining both functions of the electric motor and the generator is preferably used, but a generator without the function of the electric motor may be used. An electric motor or motor generator may be provided separately from the generator.
[0016]
  SecondThe operating point setting means of the invention is configured to set an operating point on, for example, an optimal efficiency line of a motor generator, and the efficiency is generally higher on the high rotation side also on the optimal efficiency line. The operating point is set as high as possible as long as the required oil pressure does not exceed the allowable range.
[0017]
On the other hand, in a belt-type continuously variable transmission in which a transmission gear ratio γ (= input shaft rotation speed / output shaft rotation speed) and belt tension are controlled by a hydraulic cylinder, the required oil pressure differs depending on the transmission gear ratio γ and the generator operating point ( Target speed ratio γ determined according to the rotation speed of the generator and corresponding to the input shaft speed of the transmission))^*The greater the difference between the current gear ratio γ and the smaller the vehicle speed and the smaller the vehicle speed, the greater the shift speed and the greater the shift hydraulic pressure required for the shift. Therefore, on the higher vehicle speed side where the original required hydraulic pressure is small and the gear ratio γ is small, the gear ratio γ can be greatly changed at a large gear speed, and the operating point of the generator is set to a high efficiency and high rotation speed. While γ can be greatly downshifted to the increasing side, the operating point of the generator is compared so that the change width of the transmission ratio γ, in other words, the transmission speed decreases, on the low vehicle speed side where the required hydraulic pressure is large and the transmission ratio γ is large Therefore, it is desirable to reduce the increase in required hydraulic pressure associated with the shift (downshift). In other words, the operating point setting means is configured so that, for example, the operating point (rotational speed) of the generator on the low vehicle speed side becomes low so that the required hydraulic pressure of the continuously variable transmission does not become excessive. The driving point can be set according to the vehicle speed in accordance with setting data such as a map. The operating point setting means is appropriately determined according to the hydraulic characteristics of the hydraulic continuously variable transmission.
[0018]
  The present invention is suitably applied to various hybrid type vehicles such as a series type and a parallel type equipped with an engine and a motor generator that generate power by combustion of fuel as a driving power source. 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 / distributing device such as a planetary gear device, (d) a transmission for shifting the power output from the combining / distributing device and transmitting it to the drive wheel side, and (e) separating the engine from the power transmission path. The present invention can also be applied to a hybrid vehicle having a friction engagement device. In addition,The present inventionIf at least the engine is equipped as a driving power sourcegood.
[0019]
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, and FIG. 2 is a skeleton diagram including a transmission 12. The hybrid drive device 10 generates power by combustion of fuel. The engine 14 includes a motor generator 16 used as an electric motor and a generator, and a double pinion type planetary gear unit 18. The engine 14 is connected to the sun gear 18s of the planetary gear unit 18, the motor generator 16 is connected to the carrier 18c, and the ring gear 18r is connected to the case 20 via the first brake B1. The carrier 18c is connected to the input shaft 22 of the transmission 12 via the first clutch C1, and the ring gear 18r is connected to the input shaft 22 via the second clutch C2. The planetary gear unit 18 is a synthesizing / distributing device, the sun gear 18s is a first rotating element, the carrier 18c is a second rotating element, and the ring gear 18r is a third rotating element. Further, the input shaft 22 of the transmission 12 corresponds to an output member.
[0020]
The clutches C1 and C2 and the first brake B1 are wet multi-plate hydraulic friction engagement devices that are frictionally engaged by a hydraulic actuator, and are frictionally engaged by hydraulic oil supplied from the hydraulic control circuit 24. It is like that. 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 generator 26 including the electric pump is transferred to the shift lever 30 (see FIG. 1) via the manual valve 28. Is supplied to each of the clutches C1, C2 and the brake B1 according to the operation range. The shift lever 30 is a shift operation member operated by the driver, and in this embodiment, the shift lever 30 is selected and 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, a link, or the like, and is mechanically switched according to the operation of the shift lever 30.
[0021]
The “B” range is an operation range in which a relatively large power source brake is generated due to a downshift of the transmission 12 during forward travel, and the “D” range is an operation range for forward travel. In these operation ranges, The original pressure PC is supplied from the output port 28a to the clutches C1 and C2. The original pressure PC is supplied to the first clutch C <b> 1 via the shuttle valve 31. The “N” range is an operation range that cuts off power transmission from the power source, the “R” range is an operation range that travels backward, and the “P” range cuts off power transmission from the power source and is not shown in the drawing. Therefore, the operation pressure range mechanically prevents the rotation of the drive wheels. In these operation ranges, the original pressure PC is supplied from the output port 28b to the first brake B1. The original pressure PC output from the output port 28b is also input to the return port 28c. In the “R” range, the original pressure PC is supplied from the return port 28c to the first clutch C1 via the output port 28d. It has come to be.
[0022]
The clutches C1, C2 and the brake B1 are provided with control valves 32, 34, 36, respectively, and their hydraulic pressure P_C1, P_C2, P_B1Is to be controlled. Hydraulic pressure P of clutch C1_C1Is adjusted by the ON-OFF valve 38, and the hydraulic pressure P of the clutch C2 and the brake B1 is adjusted._C2, P_B1The pressure is regulated by the linear solenoid valve 40.
[0023]
Then, according to the operating states of the clutches C1, C2 and the brake B1, the travel modes shown in FIG. 4 are established. That is, in the “B” range or the “D” range, any one of “ETC mode”, “direct connection mode”, and “motor traveling mode (forward)” is established, and in the “ETC mode”, the second clutch C2 is engaged. In a state where the first clutch C1 and the first brake B1 are released while being engaged, both the engine 14 and the motor generator 16 are operated to cause the vehicle to travel forward. In the “direct connection mode”, the engine 14 is operated to drive the vehicle forward while the clutches C1 and C2 are engaged and the first brake B1 is released. In the “motor running mode (forward)”, the motor generator 16 is operated to drive the vehicle forward while the first clutch C1 is engaged and the second clutch C2 and the first brake B1 are released. The “ETC mode” is an electric torque converter mode and corresponds to an engine / motor traveling mode, and the “direct connection mode” corresponds to an engine direct connection mode.
[0024]
FIG. 5 is a collinear diagram showing the operating state of the planetary gear unit 18 in the forward mode, wherein “S” represents the sun gear 18s, “R” represents the ring gear 18r, “C” represents the carrier 18c, and so on. Is determined by the gear ratio ρ (= the number of teeth of the sun gear 18s / the number of teeth of the ring gear 18r). Specifically, when the interval between “S” and “C” is 1, the interval between “R” and “C” is ρ, and in this embodiment, ρ is about 0.6. The torque ratio in the ETC mode (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 the steady state, the torque obtained by adding the motor torque Tm and the engine torque Te becomes the CVT 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.
[0025]
Returning to FIG. 4, in the “N” range or the “P” range, either “neutral” or “charging / engage start mode” is established, and in the “neutral” state, the clutches C1, C2 and the first brake B1 are Both are open. In the “charging / engage start mode”, the clutches C1 and C2 are disengaged and the first brake B1 is engaged, and the motor generator 16 is rotated in the reverse direction to start the engine 14, or the engine 14 passes through the planetary gear unit 18. The motor generator 16 is rotationally driven and the motor generator 16 is regeneratively controlled to generate electric power, and the battery 42 (see FIG. 1) is charged.
[0026]
In the “R” range, “motor travel mode (reverse)” or “friction travel mode” is established. In “motor travel mode (reverse)”, the first clutch C1 is engaged and the second clutch C2 and the second clutch C2 are engaged. In a state where one brake B1 is released, the motor generator 16 is operated in the reverse rotation direction to cause the vehicle to travel backward. In the “friction running mode”, with the first clutch C1 engaged and the second clutch C2 opened, the motor generator 16 is operated in the reverse rotation direction to drive the vehicle backward, while the engine 14 is operated. When the ring gear 18r is rotated in the forward direction, the first brake B1 is slip-engaged to apply an assist force in the reverse direction to the carrier 18c and further to the input shaft 22.
[0027]
The transmission 12 is a belt type continuously variable transmission, and power is transmitted from the output shaft 44 to the ring gear 50 of the differential device 48 via the counter gear 46, and power is transmitted to the left and right drive wheels 52 by the differential device 48. Distributed.
[0028]
The hybrid drive device 10 of the present embodiment is controlled by the HVECU 60 shown in FIG. The HVECU 60 includes a CPU, a RAM, a ROM, and the like, and performs signal processing in accordance with a program stored in advance in the ROM while using a temporary storage function of the RAM, whereby an electronic throttle ECU 62, an engine ECU 64, an M / GECU 66, The T / MECU 68, the ON / OFF valve 38 of the hydraulic control circuit 24, the linear solenoid valve 40, the starter 70 of the engine 14 and the like are controlled. The electronic throttle ECU 62 controls the opening and closing of the electronic throttle valve 72 of the engine 14, the engine ECU 64 controls the engine output by the fuel injection amount of the engine 14, the variable valve timing mechanism, the ignition timing, etc. The M / GECU 66 is an inverter. The T / MECU 68 controls the power running torque, regenerative braking torque, etc. of the motor generator 16 via 74, and the T / MECU 68 has a transmission gear ratio γ (= input shaft rotational speed Nin / output shaft rotational speed Nout), belt tension, etc. Is to control. The hydraulic control circuit 24 includes a circuit for controlling the transmission gear ratio γ and the belt tension of the transmission 12, and a necessary hydraulic pressure is generated by the electric hydraulic pressure generator 26. The starter 70 is an electric motor, and the pinion provided on the motor shaft meshes with a ring gear provided on a flywheel or the like of the engine 14 to crank the engine 14.
[0029]
The HVECU 60 is supplied with a signal representing an operation amount θac of an accelerator pedal 78 as an accelerator operation member from the accelerator operation amount sensor 76 and an idle contact signal that is turned ON when the accelerator is OFF, and from the shift position sensor 80 to the shift lever 30. A signal representing the operation range (shift position) is supplied. The brake ECU 90 is supplied with a brake ON / OFF signal indicating whether or not the brake pedal is depressed, a brake hydraulic pressure or a pedal depression force representing a brake force, and the like. 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, the engine rotation speed (rotation speed) Ne, the motor rotation speed (rotation speed) Nm, and the input shaft, respectively. Signals representing the rotation speed (rotation speed of the input shaft 22) Nin and the output shaft rotation speed (rotation speed of the output shaft 44) Nout are supplied. The output shaft rotational speed Nout corresponds to the vehicle speed V. In addition, various signals representing the operation state such as the storage amount SOC of the battery 42 are supplied. The storage amount SOC may be simply a battery voltage, or may be obtained by sequentially integrating the charge / discharge amount.
[0030]
The HVECU 60 basically has the functions shown in FIG. 6 and implements the travel 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 advance means 104 implements the “motor travel mode (advance)”. The charge control means 106 implements a “charging / engage start mode”, the motor reverse means 108 implements a “motor travel mode (reverse)”, and the engine assist reverse means 110 performs “friction travel”. The ETC mode control means 100 and the direct connection mode control means 102 constitute an engine advance 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 storage amount SOC, the shift position of the shift lever 30, and the like, and the driving is performed in the determined travel mode. The above means are switched so that
[0031]
In the “direct connection mode” by the direct connection mode control means 102, the accelerator operation is released (accelerator OFF) or the brake pedal is operated while the shift lever 30 is operated to the “B” range and traveling at a predetermined vehicle speed or higher. When a stepping operation (ON operation) is performed, the motor generator 16 that is rotationally driven by the kinetic energy of the vehicle is regeneratively controlled so that a regenerative braking force is applied to the vehicle and the battery 42 is charged. That is, in this embodiment, the regenerative braking device is configured with the direct connection mode control means 102 as the center. Even when the shift lever 30 is in the “D” range, the same regeneration control is performed as necessary.
[0032]
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, and is repeated at a predetermined cycle time. Executed. Note that during this regenerative control, fuel injection to the engine 14 is stopped.
[0033]
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 an engine disconnecting condition that allows the engine 14 to be disconnected and stopped can be satisfied. The engine disconnection conditions include, for example, that the coolant 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 respectively detected by temperature sensors and supplied to the HVECU 60 via the engine ECU 64 and the T / MECU 68.
[0034]
If the engine disconnection condition is satisfied, the engine 14 is disconnected from the power transmission path by releasing the second clutch C2 by the linear solenoid valve 40 in step S3. As a result, the engine 14 stops rotating due to its own rotational resistance such as pump action and friction. In step S4, the operating point (target rotational speed Nm) of the motor generator 16 is determined according to the regeneration required torque Trq.^*) And the shift control of the belt type continuously variable transmission 12 is performed so that the motor generator 16 is rotationally driven at the operating point. Even in step S2 where regenerative control is performed while the engine 14 is rotated as it is without disconnecting the engine 14, the operating point of the motor generator 16 (target rotational speed Nm) according to the regenerative request torque Trq.^*) And the shift control of the belt type continuously variable transmission 12 is performed so that the motor generator 16 is rotationally driven at the operating point.
[0035]
FIG. 8 is a flowchart for specifically explaining the control contents of steps S2 and S4. In step R1, the regenerative request torque Trq is calculated according to the vehicle speed V. The driver's regeneration request torque Trq is generally larger as the vehicle speed V is higher, and is obtained from a predetermined data map, for example, as shown in FIG. FIG. 9 shows the torque when viewed from the output shaft 44 side of the belt type continuously variable transmission 12 when the accelerator is OFF and the brake is OFF. From this, the input shaft 22 side (motor generator) is considered in consideration of the gear ratio γ. 16 side) to 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.
[0036]
In step R2, the operating point of the motor generator 16, that is, the target rotational speed Nm is calculated from the regenerative request torque Trq.^*Is calculated. The calculation of the operating point is performed using a predetermined data map as shown in FIG. 10, for example. When the engine 14 indicated by the solid line is disconnected (step S4), the engine 14 indicated by the alternate long and short dash line is rotated. In the case of (step S2), it is set separately. Since the inertia torque of the engine 14 is eliminated when the engine 14 is disconnected, the speed change required when the input shaft rotational speed Nin is increased by downshifting so that the speed ratio γ of the belt type continuously variable transmission 12 is increased. The hydraulic pressure becomes lower and the operating point can be set higher.
[0037]
When setting the operating point, basically, it is determined to operate on the optimal efficiency line L1 based on the efficiency map of the motor generator 16 shown in FIG. 11, and the high efficiency side is also set on the optimal efficiency line L1. Since the efficiency is higher, it is desirable to set the operating point as high as possible within the range where the required hydraulic pressure of the belt type continuously variable transmission 12 does not exceed the allowable range.
[0038]
On the other hand, the belt-type continuously variable transmission 12 of this embodiment is a bandone type in which the transmission ratio γ and the belt tension are controlled by a hydraulic cylinder, and the belt tension is controlled by the hydraulic pressure of the driven hydraulic cylinder. As shown in FIG. 12, the required hydraulic pressure increases as the gear ratio γ increases, and the required hydraulic pressure increases as the vehicle speed decreases. Further, the target speed ratio γ determined according to the operating point of the motor generator 16, that is, the input shaft rotational speed Nin.^*The greater the difference between the current gear ratio γ and the current gear ratio, the greater the gear shift speed and the greater the hydraulic pressure required for gear shift. Accordingly, 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 greatly 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 greatly 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, the operating point of the motor generator 16 is set so that the change width of the gear ratio γ, that is, the gear shifting speed becomes small. It is necessary to set to a relatively low rotation and to reduce the increase in the required hydraulic pressure accompanying the shift.
[0039]
The map shown in FIG. 10 is set so that the required hydraulic pressure of the belt-type continuously variable transmission 16 is not excessive from this point of view, and the motor generator 16 is operated at the lower vehicle speed side where the regenerative request torque Trq is smaller. The point is set to be low rotation. The map in FIG. 10 is the same regardless of whether or not the brake pedal is depressed, and the same operating point (target rotational speed Nm^*) Is maintained, and only the regenerative torque of the motor generator 16 is increased or decreased according to the increase or decrease of the braking force.
[0040]
Returning to FIG. 8, in step R3, the motor generator 16 operates at the operating point (target rotational speed Nm).^*) So that the belt-type continuously variable transmission 12 is rotated.^*Is calculated. Specifically, the target rotational speed Nm^*Is divided by the actual output shaft rotational speed Nout. In step R4, the speed ratio γ of the belt type continuously variable transmission 12 is changed to the target speed ratio γ.^*A gear shift command for shifting the gear is output to the T / MECU 68, and gear shift control is performed accordingly.
[0041]
The solid line in FIG. 13 indicates the shift speed and rotation of the belt-type continuously variable transmission 12 when the operating point of the motor generator 16 is obtained according to the flowchart in FIG. 8 and the shift control of the belt-type continuously variable transmission 12 is performed. It is an example of a time chart showing changes in speed Nin (= motor rotation speed Nm) and Nout. The one-dot chain line in FIG. 13 is a conventional example, and the speed change speed increases as the vehicle speed V decreases (the output shaft rotational speed Nout decreases). Therefore, a larger hydraulic pressure is required, and the pump load may exceed the allowable range or the belt may slip.
[0042]
Returning to FIG. 7, in step S <b> 5, the allowable maximum generated hydraulic pressure of the electric hydraulic pressure generator 26 that generates the hydraulic pressure required for the belt-type continuously variable transmission 12 and the actual shift speed of the belt-type continuously variable transmission 12 are determined. calculate. For example, as shown in FIG. 14, the allowable maximum hydraulic pressure is calculated from the torque characteristics of the oil pump motor, the volume efficiency of the oil pump and the friction (function of the oil temperature), and specifically, individual unit performance (actual machine data). ) And control with a map. In step S6, the regenerative torque limit value of the motor generator 16 that can perform the regenerative control while avoiding the belt slip of the belt type continuously variable transmission 12 based on the maximum allowable 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 Trq> Trg, the regenerative control of the motor generator 16 is executed in step S8 with the regenerative torque limit value Trg, and Trq ≦ Trg. In this case, in step S9, regeneration control of the motor generator 16 is executed with the regeneration required torque Trq. Accordingly, the regeneration control of the motor generator 16 is performed while reliably preventing the belt of the belt type continuously variable transmission 12 from slipping.
[0043]
Here, in the present 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, and the second clutch C2 is satisfied when the engine disconnection condition is satisfied. Since the engine 14 is disconnected from the power transmission path, the battery 14 is efficiently charged by disconnecting the engine 14 while avoiding a decrease in power performance and emission due to deterioration in restartability of the engine 14. It is possible to achieve both the restartability of the engine 14 and the regeneration efficiency.
[0044]
Further, the operating point at the time of regenerative control of the motor generator 16 is obtained separately depending on whether or not the engine 14 is disconnected using two types of maps set in advance as shown in FIG. Since the belt-type continuously variable transmission 12 is controlled so that the generator 16 is rotationally driven, appropriate charging control can be performed depending on 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 rotationally driven on the high rotation side with high efficiency while avoiding an increase in hydraulic pressure during shifting due to the inertia of the engine 14. The battery 42 can be charged efficiently.
[0045]
Further, the map for obtaining the operating point in FIG. 10 is set so that the required hydraulic pressure of the belt type continuously variable transmission 12 is taken into consideration and the required hydraulic pressure is not excessive. Therefore, the motor generator 16 is rotated at the operating point. At the time of gear shifting for driving, it is possible to prevent the necessary oil pressure from becoming excessive and fuel consumption from deteriorating due to an increase in pump load, or belt slippage due to insufficient oil pressure. Further, on the high vehicle speed side where the required hydraulic pressure is small and the gear ratio γ is small, that is, on the side where the regenerative request torque Trq is large, the operating point of the motor generator 16 is set to the high rotation side, and the belt is driven to rotate at the high rotation. Since the variable continuously variable transmission 12 is shift-controlled, the battery 42 can be charged efficiently.
[0046]
Further, the map for obtaining the driving point in FIG. 10 is the same regardless of whether or not the brake pedal is depressed, and the same driving point (target rotational speed Nm).^*) Is maintained, and the regenerative torque of the motor generator 16 is only increased or decreased in accordance with the increase or decrease of the brake force.^*Change, and further, shifting of the belt-type continuously variable transmission 12 is prevented, and the braking force is stabilized.
[0047]
Of the series of signal processing performed by the direct connection mode control means 102, the part that executes steps S1 and S3 in FIG. 7 constitutes an engine disconnecting means together with the second clutch C2 and the linear solenoid valve 40, and step S2 Of the execution contents of S4 and S4, the part for executing steps R1 and R2 in FIG. 8 functions as operating point setting means, and the part for executing steps R3 and R4 constitutes shift control means together with T / MECU 68. .
[0048]
As mentioned above, although the Example of this invention was described in detail based on drawing, this is only one Embodiment of this invention, and this invention is the aspect which added the various change and improvement based on the knowledge of those skilled in the art. Can be implemented.
[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 diagram 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;
4 is a diagram for explaining the relationship between several travel modes established in the hybrid drive device of FIG. 1 and the operating states of clutches and brakes. FIG.
5 is a collinear diagram showing the relationship between the rotational speeds of the rotating elements of the planetary gear device in the ETC mode, the direct connection mode, and the motor travel mode (forward movement) of FIG. 4;
6 is a block diagram showing some functions provided in the HVECU of FIG. 1. FIG.
FIG. 7 is a flowchart illustrating an operation when a motor generator is regeneratively controlled in a direct connection mode.
FIG. 8 is a flowchart illustrating specific contents of steps S2 and S4 in FIG.
FIG. 9 is a diagram illustrating an example of a data map used when obtaining regeneration request torque Trq in step R1 of FIG.
10 is a diagram for explaining an example of a data map used when obtaining an operating point of a motor generator in step R2 of FIG.
FIG. 11 is a diagram for explaining an example of an optimum efficiency line of a motor generator.
FIG. 12 is a diagram for explaining an example of a correlation between a gear ratio of a belt-type continuously variable transmission and a required hydraulic pressure.
FIG. 13 is an example of a time chart showing a change in operating state of each part when regenerative control is performed according to the flowchart of FIG. 7;
FIG. 14 is a diagram for explaining how to obtain the allowable maximum generated hydraulic pressure in step S5 of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10: Hybrid drive device 12: Belt type continuously variable transmission 14: Engine 16: Motor generator (generator) 40: Linear solenoid valve (engine disconnecting means) 42: Battery 60: HVECU 68: T / MECU (shift control means) 102 : Direct connection mode control means (regenerative braking device) C2: Second clutch (engine disconnection means)
Steps S1 and S3: Engine disconnecting means
Steps R1, R2: Operating point setting means
Steps R3 and R4: Shift control means

Claims (2)

It has an engine that operates by combustion of fuel as a driving power source, and when the generator is driven to rotate by the kinetic energy of the vehicle, the regenerative braking force is applied to the vehicle by regenerative control of the generator and the battery is charged. In a regenerative braking device for a vehicle,
While the generator is connected to the wheels via a transmission,
Engine separation means for determining whether or not the state of the vehicle satisfies a predetermined engine disconnection condition during the regenerative control, and when the engine disconnection condition is satisfied, disconnects the engine from the power transmission path ;
An operating point setting means for separately setting an operating point of the generator at the time of the regenerative control depending on whether or not the engine is disconnected by the engine disconnecting means;
Shift control means for controlling the shift of the transmission so that the generator is rotationally driven at the operating point;
Regenerative braking apparatus for a vehicle, characterized in that it comprises a. The transmission is a hydraulic continuously variable transmission,
The operating point setting means is configured to set the operating point of the generator in consideration of the required hydraulic pressure of the hydraulic continuously variable transmission.
The regenerative braking device for a vehicle according to claim 1 .

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