JP4552355B2 - Vehicle drive control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle drive control device, and more particularly, to shift control when a power interrupt mechanism is connected and a drive source is switched during traveling.
[0002]
[Prior art]
A hybrid drive for vehicles having a power interrupting mechanism provided between a prime mover such as an internal combustion engine and a transmission, and an electric motor capable of generating a driving force via the transmission separately from the prime mover The device is known. One type of such hybrid drive apparatus, when the driver's output request amount is small, travels with only the electric motor as the drive source in the motor travel mode that shuts off the power interrupting mechanism, while the driver's output request amount is large. In some cases, the motor is driven using the prime mover as a drive source in a prime mover traveling mode to which a power interrupting mechanism is connected. The device described in Japanese Patent Laid-Open No. 9-322305 is an example, and when the driver's output request amount suddenly increases and switches from the motor travel mode to the prime mover travel mode, the output of the electric motor is output until the prime mover starts. By increasing the value temporarily, excellent responsiveness can be obtained.
[0003]
[Problems to be solved by the invention]
However, when the driver's output demand becomes large, the transmission is generally downshifted. Therefore, the input rotational speed of the transmission increases, and the time until the prime mover reaches the synchronous rotational speed, that is, the mode switching time is long. Thus, there is a problem that it takes time until the driving force by the prime mover can be obtained. Moreover, since the rotational speed of the electric motor increases as the input rotational speed of the transmission increases, the motor torque decreases accordingly, and the driving force does not necessarily increase regardless of an increase in the output of the electric motor or a downshift of the transmission. There was another problem that the effect could not be obtained sufficiently and the noise (beating noise) of the electric motor increased with the increase in the rotational speed.
[0004]
The present invention has been made in the background of the above circumstances, and the object of the present invention is to reduce the mode switching time when switching the drive source by connecting the power interrupting mechanism during traveling and reducing the driving force by the prime mover. It is intended to obtain the driving force promptly and to obtain a large driving force according to the required output amount even during the mode switching.
[0005]
[Means for Solving the Problems]
In order to achieve such an object, the first invention provides: (a) a power interrupting mechanism is provided between an internal combustion engine used as a prime mover and a transmission, and the transmission is separated from the internal combustion engine via the transmission; An electric motor that can generate a driving force, and a motor travel mode that travels using the electric motor in a state where the power interrupting mechanism is shut off, and the internal combustion engine is connected to the power interrupting mechanism. in a vehicle having a prime mover driving mode in which the vehicle travels using, switching to (b) with an increase of the amount of output required by a driver during vehicle traveling from the motor drive mode by connecting the power interrupting mechanism the prime mover driving mode said transmission comprising a drive control device when downshifting with, the (c) said mode switching, to correspond to the input rotational speed of said transmission of said internal combustion engine A downshift limit unit that limits a downshift of the transmission until the synchronized rotation speed substantially coincides, (d) the mode switching, the motor increases the output of the electric motor in response to the amount of output required by a driver output And increasing means .
The synchronous rotational speed is the rotational speed of the internal combustion engine when the rotational speeds of the engaging members on the transmission side and the internal combustion engine side of the power interrupt mechanism are the same.
[0007]
【The invention's effect】
In such a vehicle drive control apparatus, when switching from the motor drive mode while the vehicle is traveling to the prime mover drive mode, its transmission downshift to the rotational speed of the internal combustion engine is substantially coincident with the synchronous rotational speed is limited because, without the input rotation speed of the transmission is increased by the downshift, it is possible to quickly synchronize the rotational speed of the internal combustion engine with respect to the input rotational speed, by an internal combustion engine and connect the power interrupting mechanism The mode switching time until the driving force can be obtained is shortened.
[0008]
Also, until substantially coincident rotational speed and an input rotational speed of the internal combustion engine, the downshifting of the transmission is limited, since the increase in the rotational speed of the electric motor is also limited accordingly, the mode switching to the driver If the output of the electric motor is increased in accordance with the increase in the output request amount, the driving force is increased in accordance with the increase in the output, and excellent driving force performance corresponding to the increase in the output request amount can be obtained. An increase in noise (beat sound) of the electric motor accompanying an increase in rotational speed is prevented.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Electric motor capable of generating a driving force via a speed change device may be provided in series between the transmission and the power interrupting mechanism, but provided in parallel with the internal combustion engine through a power transmission mechanism Various embodiments are possible, such as
[0010]
As the electric motor, a motor generator that also functions as a generator is preferably used. As the prime mover, an internal combustion engine that generates power by burning fuel such as a gasoline engine is used.
[0011]
The power interrupting mechanism may be one that simply connects and disconnects power transmission by clutch engagement and disengagement control, in which case the synchronous rotational speed matches the input rotational speed of the transmission, but a plurality of planetary gear units or the like Various modes are possible, such as one in which the coupling state of a gear mechanism having a rotating element is switched by a clutch or brake to connect or disconnect power transmission. As the clutch and the brake, a friction engagement device that is frictionally engaged by hydraulic pressure or the like is desirable.
[0012]
The transmission may be a continuously variable transmission such as a belt type or a toroidal type that can continuously change the gear ratio, or a stepped transmission such as a planetary gear type or a two-shaft meshing type. Any device that can change the transmission gear ratio may be used.
[0013]
The downshift limiting means is configured to substantially prohibit downshifting and maintain the gear ratio substantially constant (a constant gear in the case of a stepped transmission), for example, when traveling in the prime mover traveling mode, etc. Various modes can be adopted such that it is only necessary to reduce the speed of change of the gear ratio compared to a normal downshift other than during mode switching. Further, it is sufficient that the actual downshift, that is, the change in the gear ratio is limited until the rotational speed of the internal combustion engine substantially matches the synchronous rotational speed, and the response is like a transmission controlled by a hydraulic actuator. If there is a delay, the restriction on the downshift control may be released earlier by the response delay. Note that upshifting is not necessarily limited, and it is possible to upshift when switching modes.
[0014]
The present invention comprises (a) a synchronizing means for controlling the output of the internal combustion engine so that the rotational speed of the internal combustion engine exceeds the synchronous rotational speed at the time of mode switching, and (b) the rotational speed of the internal combustion engine is the synchronous rotational speed. And connecting means for connecting the power interrupting mechanism in a state where the power interrupting mechanism is exceeded, in which case the driving force may be reduced when the power interrupting mechanism is connected, causing the driver to feel uncomfortable. Absent. The motor output increasing means is configured to control the output according to the driver's requested output amount within a range not exceeding the allowable maximum output of the electric motor, for example.
[0015]
The prime mover running mode, but may be traveling only internal combustion engine as a drive source, Ru can be used both for the internal combustion engine and an electric motor as a drive source.
[0016]
【Example】
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 vehicle hybrid drive control device 10 according to an embodiment of the present invention. FIG. 2 is a skeleton diagram including a transmission 12, and the hybrid drive control device 10 includes a fuel. The engine 14 generates power by combustion of the motor, the motor generator 16 used as an electric motor and a generator, and a double pinion type planetary gear unit 18, and is used by being mounted horizontally in a vehicle. . 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 engine 14 is an internal combustion engine and corresponds to a prime mover.
[0017]
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 shift position. The shift lever 30 is a shift operation member that is operated by the driver. In this embodiment, the shift lever 30 is selected and operated in five shift positions 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 can be mechanically switched in accordance with the operation of the shift lever 30.
[0018]
The “B” position is a shift position in which a relatively large power source brake is generated due to a downshift of the transmission 12 during forward travel, and the “D” position is a shift position for forward travel. In these shift positions, 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” position is a shift position that cuts off power transmission from the power source, the “R” position is a shift position that travels backward, and the “P” position cuts off power transmission from the power source and is not shown in the drawing. The shift positions mechanically prevent the drive wheels from rotating, and at these shift positions, 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” position, 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.
[0019]
The clutches C1, C2 and the brake B1 are provided with control valves 32, 34, 36, respectively, and their hydraulic pressures P _C1 , P _C2 , P _B1 are controlled. The hydraulic pressure P _C1 of the clutch C1 is regulated by the ON-OFF valve 38, and the clutch C2 and the brake B1 are regulated by the linear solenoid valve 40.
[0020]
Then, according to the operating states of the clutches C1, C2 and the brake B1, the travel modes shown in FIG. 4 are established. In other words, in the “B” position or the “D” position, any one of “ETC travel mode”, “direct connection travel mode”, and “motor travel mode (forward)” is established, and in the “ETC travel mode”, the second The engine 14 and the motor generator 16 are operated together with the clutch C2 engaged and the first clutch C1 and the first brake B1 opened, in other words, the sun gear 18s, the carrier 18c, and the ring gear 18r are relatively rotatable. Then, torque is applied to the sun gear 18s and the carrier 18c, and the ring gear 18r is rotated to move the vehicle forward. In the “directly connected running mode”, the vehicle is driven forward by operating the engine 14 with the clutches C1 and C2 engaged and the first brake B1 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. In the “motor running mode (forward)”, the motor generator 16 is regeneratively controlled when the accelerator is OFF, etc., so that the battery 42 (see FIG. 1) is charged by generating electricity with the kinetic energy of the vehicle and the braking force is applied to the vehicle. Can be generated.
[0021]
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 travel 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 a 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.
[0022]
Returning to FIG. 4, in the “N” position or the “P” position, either “neutral” or “charging / engage start mode” is established, and in “neutral”, 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.
[0023]
In the “R” position, “motor travel mode (reverse)” or “friction travel mode” is established, and in “motor travel mode (reverse)”, the first clutch C1 is engaged and the second clutch C2 and the second clutch With the one brake B1 released, the motor generator 16 is rotationally driven in the reverse direction to reversely rotate the carrier 18c and further the input shaft 22, thereby causing the vehicle to travel backward. In the “friction running mode”, the engine 14 is operated with the first clutch C1 engaged and the second clutch C2 opened, the sun gear 18s is rotated in the forward direction, and the ring gear is rotated along with the rotation of the sun gear 18s. In a state in which 18r is rotated in the forward direction, the reverse rotation is applied to the carrier 18c by slipping engagement of the first brake B1 and limiting the rotation of the ring gear 18r, and the vehicle travels backward. At the same time, the motor generator 16 may be driven to rotate in the reverse direction (power running control).
[0024]
The transmission 12 is a belt-type continuously variable transmission (CVT). Power is transmitted from the output shaft 44 to the ring gear 50 of the differential device 48 via the counter gear 46, and the differential device 48 transmits left and right drive wheels ( Power is distributed to the front wheels 52. The transmission 12 includes a pair of variable pulleys 12a and 12b and a transmission belt wound around them, and the V-groove width is changed by the hydraulic cylinder of the variable pulley 12a on the primary side (input side). The transmission gear ratio γ (= input rotation speed Nin / output rotation speed Nout) is continuously changed, and the belt clamping pressure (tension) is adjusted by the hydraulic cylinder of the variable pulley 12b on the secondary side (output side). It has become. The hydraulic control circuit 24 includes a circuit for controlling the speed ratio γ and belt tension of the transmission 12, and hydraulic oil is supplied from a common electric hydraulic pressure generator 26.
[0025]
The hybrid drive control apparatus 10 of the present embodiment is configured such that the travel mode is switched 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. A power running torque, a regenerative braking torque, and the like of the motor generator 16 are controlled via 74, and a T / MECU 68 controls a speed ratio γ of the transmission 12, a belt tension, and the like. The hydraulic control circuit 24 includes a circuit for controlling the speed ratio γ and belt tension of the transmission 12. 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.
[0026]
The HVECU 60 is supplied with a signal representing the operation amount θac of the accelerator pedal 78 as an accelerator operation member from the accelerator operation amount sensor 76 and a signal representing the operation position (shift position) of the shift lever 30 from the shift position sensor 80. Is supplied. The engine rotation speed sensor 82, the motor rotation speed sensor 84, the input rotation speed sensor 86, and the output rotation speed sensor 88 are respectively referred to as an engine rotation speed (rotation speed) Ne, a motor rotation speed (rotation speed) Nm, and an input rotation speed ( Signals representing the rotational speed (Nin) of the input shaft 22 and the output rotational speed (rotational speed of the output shaft 44) Nout are supplied. In addition, various signals representing the operation state such as the storage amount SOC of the battery 42 are supplied. The output rotation speed Nout corresponds to the vehicle speed V.
[0027]
Further, in this embodiment, as shown in FIG. 6, in addition to the hybrid drive control device 10, a rear motor generator 90 is provided as a second drive source, and the battery 42 is electrically connected via an inverter 92. It is connected and power running control and regenerative control are performed. The motor generator 90 is mechanically connected to the left and right rear wheels 96 via a differential device 94 and drives the rear wheels 96 to rotate by power running control, and applies regenerative braking force to the rear wheels 96 by regenerative control. Let The rear motor generator 90 is also controlled by the HVECU 60. For example, the rear wheel 96 is driven to rotate in addition to the front wheels 52 under predetermined conditions such as when the vehicle starts or when traveling on a low μ road. ing.
[0028]
Here, the T / MECU 68 includes a CPU, a RAM, a ROM and the like, similar to the HVECU 60, and executes signal processing in accordance with a program stored in the ROM in advance using the temporary storage function of the RAM. By reading various information such as the input rotational speed Nin, the output rotational speed Nout, and the accelerator operation amount θac, performing signal processing relating to the shift control and clamping pressure control of the transmission 12, and outputting a command signal to the HVECU 60, According to the command signal, the hydraulic pressure control circuit 24 is controlled, or the hydraulic pressure control circuit 24 is directly controlled by the T / MECU 68, thereby performing the shift control and the clamping pressure control of the transmission 12. That is, the control device for the transmission 12 is configured with the T / MECU 68 as a main component.
[0029]
In the shift control, for example, as shown in FIG. 7, the target input rotation speed NINT is calculated from a predetermined map using the accelerator operation amount θac and the vehicle speed V (corresponding to the output rotation speed Nout) as parameters, and the actual input rotation speed is calculated. The hydraulic pressure of the hydraulic cylinder of the input side variable pulley 12a is feedback-controlled so that Nin matches the target input rotational speed NINT. In FIG. 7, γmax is the maximum gear ratio, and γmin is the minimum gear ratio. The clamping pressure control of the transmission 12 controls the hydraulic pressure of the hydraulic cylinder of the output side variable pulley 12b so that the transmission belt wound around the pair of variable pulleys 12a and 12b does not slip. As shown in FIG. 8, the required hydraulic pressure (corresponding to the belt clamping pressure) is calculated from a predetermined map using the accelerator operation amount θac and the transmission gear ratio γ corresponding to the transmission torque as parameters, and the output side variable pulley according to the required hydraulic pressure The hydraulic control of the hydraulic cylinder 12b is performed.
[0030]
On the other hand, FIG. 9 shows that the vehicle travels using the engine 14 as a drive source from the “motor travel mode (forward travel)” in the engine stop state during forward travel when the shift lever 30 is operated to the “D” position or the “B” position. It is a flowchart explaining the operation | movement at the time of switching to a "direct connection driving mode", and is mainly performed by the signal processing by HVECU60, engine ECU64, and M / GECU66. FIG. 10 is a flowchart for explaining the shift control of the transmission 12 at the time of the mode switching, and is executed mainly by signal processing by the T / MECU 68. FIG. 11 shows the change in the operating state of each part at the mode switching. It is a time chart explaining.
[0031]
In step R1 of FIG. 9, it is determined whether or not the mode switching determination from the “motor travel mode (forward)” to the “direct connection travel mode” has been performed. This mode switching determination is made based on the accelerator operation amount θac, the vehicle speed V, the storage amount SOC of the battery 42, and the like. For example, in inertial traveling with the accelerator OFF where the accelerator pedal 78 is not depressed, the “motor traveling mode (forward)” is selected. When the accelerator pedal 78 is depressed while the vehicle is traveling at a predetermined vehicle speed or more, and the driver's output request amount obtained from the accelerator operation amount θac and the vehicle speed V exceeds a predetermined value, the “directly connected traveling mode” is entered. A decision to switch is made. Time t _{1 in} FIG. 11 is the time when the mode switching determination is made, and is when the mode switching determination is made by depressing the accelerator pedal 78 from the accelerator OFF to the fully open state . "Directly linked traveling mode" corresponds to the prime mover traveling mode.
[0032]
When the mode switching determination is made, step R2 is executed, and the output of the motor generator 16 is controlled according to the accelerator operation amount θac within a range not exceeding the allowable maximum output. The rear side motor generator 90 may also be subjected to power running control. Step R2 functions as a motor output increasing means, and the output of the motor generator 16 (and 90) is increased in accordance with the accelerator operation amount θac so that the driving force by the engine 14 is obtained by mode switching. A predetermined driving force performance is obtained. Further, the motor torque may be increased by the driver's required driving force using the accelerator operation amount θac and the vehicle speed V as parameters.
[0033]
In step R3, the engine 14 is cranked and started by the starter 70, and the target rotational speed is higher by a predetermined rotational speed (for example, about 200 rpm) than the input rotational speed Nin (same as the motor rotational speed Nm), which is a synchronous rotational speed. As the rotation speed, output control of the engine 14 is performed. In this mode switching, when the second clutch C2 that is engaged and controlled in order to establish the “direct running mode” functions as a power interrupting mechanism, the rotational speeds of the engaging elements of the second clutch C2 coincide. In this case, the engine rotational speed Ne coincides with the input rotational speed Nin. In step R3, the engine rotational speed Ne is quickly increased to the synchronous rotational speed. The electronic throttle valve 72 and the like are feedback-controlled using a slightly higher rotational speed as a target rotational speed.
Step R3 functions as a synchronization means.
[0034]
In Step R4, the linear solenoid valve 40 is controlled to perform the first fill (rapid filling) of the hydraulic oil from the control valve 34 to the second clutch C2, and the second clutch C2 is brought into a predetermined low pressure standby state. By controlling the hydraulic pressure P _C2 , the second clutch C2 is held in a state immediately before engagement against the return spring. In FIG. 11, the portion A in the column of the hydraulic pressure P _C2 is a first fill portion, and the portion B is a low pressure standby portion.
[0035]
In step R5, it is determined whether or not the engine rotational speed Ne exceeds the input rotational speed Nin, and the hydraulic pressure P _C2 of the second clutch C2 is maintained in the low pressure standby state while Ne ≦ Nin. When Ne> Nin, step R6 is executed, and the linear solenoid valve 40 is controlled to supply hydraulic oil to the second clutch C2 from the control valve 34, whereby the hydraulic pressure P _C2 becomes the hydraulic characteristics of the accumulator, etc. And the engagement torque of the second clutch C2 is gradually increased. This step R6 functions as a connecting means. When the engagement control of the second clutch C2 is performed after the engine rotational speed Ne exceeds the input rotational speed Nin in this way, the driving force is applied when the second clutch C2 is connected. Does not cause the driver to feel uncomfortable. FIG time t ₂ of 11, the determination in step R5 engine rotational speed Ne is higher than the input rotation speed Nin is the time became to YES (the positive). The determination may be made using the motor rotation speed Nm instead of the input rotation speed Nin.
[0036]
In step R7, it is determined whether or not the engine rotational speed Ne substantially matches the input rotational speed Nin by the engagement control of the second clutch C2. If the two substantially match, the linear solenoid valve 40 controls the control valve 34 in step R8. Is fully opened, the hydraulic pressure P _C2 is raised to the line hydraulic pressure P _L and the second clutch C2 is completely engaged. As a result, the “direct running mode” is set, and in the subsequent step R9, the output of the engine 14 is controlled in accordance with the accelerator operation amount θac, and the operation of the motor generator 16 (and 90) is stopped. It will be possible to run with driving force. The time t _{3 in} FIG. 11 is the time when the engine rotational speed Ne substantially coincides with the input rotational speed Nin and the determination in step R7 becomes YES (positive).
[0037]
Further, in step Q1 of FIG. 10, it is determined whether or not the mode switching determination from the “motor traveling mode (forward)” to the “directly connected traveling mode” has been made in the same manner as in step R1. If so, it is determined in step Q2 whether the downshift relaxation condition is satisfied. The downshift mitigation condition is an execution condition for executing the main control for limiting the normal downshift performed according to the map shown in FIG. 7, and specifically, the accelerator operation amount θac is equal to or greater than a predetermined value and the accelerator operation amount θac. When the change speed of the vehicle is greater than or equal to a predetermined value, for example, when the accelerator pedal 78 is depressed from the accelerator OFF state to the fully open position, a sudden downshift that rapidly increases the gear ratio γ is performed in normal shift control. It is. Then, when both of the above steps Q1 and Q2 are satisfied, step Q3 and subsequent steps are executed.
[0038]
In step Q3, the flag step is set to “0”, and the current input rotational speed Nin (time t _{1 in} FIG. 11) is set to the reference rotational speed Nin0. In step Q4, the engine rotational speed Ne is the synchronous rotational speed. It is determined whether or not a rotational speed (Nin + α ₁ ) obtained by adding a predetermined value α ₁ to a certain input rotational speed Nin is exceeded.
The predetermined value α ₁ is a value of, for example, about 30 to 50 rpm, and step Q4 is a step of determining whether or not the engine speed Ne substantially exceeds the input speed Nin. If Ne ≦ Nin + α ₁ , Nin + α ₁ is set as the target input rotational speed NINT ^* in step Q5, and the target input rotational speed NINT ^* is used in place of the target input rotational speed NINT to change the speed of the transmission 12. In addition to performing control, the flag step is set to “1” in step Q6, and the determination in step Q4 is repeated.
Since the predetermined value α ₁ is a very small value of about 30 to 50 rpm, the downshift is substantially prohibited until Ne> Nin + α ₁ and the determination in step Q4 becomes YES, and the current gear ratio γ is substantially reduced. Will be maintained. The broken line shown in the rotational speed column of FIG. 11 is the target input rotational speed NINT ^* , which is approximately higher than the input rotational speed Nin by a predetermined value α ₁ until time t ₂ when the engine rotational speed Ne exceeds the input rotational speed Nin. Maintained at a constant value. Steps Q4 and Q5 function as downshift limiting means. Strictly speaking, the input rotational speed Nin slightly increases due to the output increase control of the motor generator 16, and the target input rotational speed NINT ^* also slightly increases accordingly.
[0039]
If Ne> Nin + α ₁ and the determination in step Q4 is YES, step Q7 is executed to determine whether or not the flag step is “1”. FIG time t ₂ of the 11 determination in step Q4 is substantially coincident with the time became to YES. When step = 0, that is, when the engine 14 is in an operating state even in the “motor running mode”, step Q10 is immediately executed. When step = 1, steps Q8 and Q9 are executed. At step Q8, the reference rotational speed obtained by adding a predetermined value alpha ₂ in the rotational speed Nin0 (Nin0 + α ₂₎ is set to the target input rotational speed NINT ^*, instead of the target input rotational speed NINT ^* the target input rotational speed NINT Is used to control the shift of the transmission 12. The predetermined value α ₂ is used to moderately downshift while preventing the driving force from being reduced due to a sudden downshift. The accelerator at the start of this control (when the determination in step Q2 is YES) Using the manipulated variable θac and its change speed as a parameter, a larger value is set when the value is larger, and the input rotational speed Nin increases according to this downshift. In step Q9, a rotational speed difference (NINT ^* −Nin) obtained by subtracting the actual input rotational speed Nin from the target input rotational speed NINT ^* is determined from a predetermined value α ₃ (for example, about several tens to 100 rpm). It is determined whether or not the engine speed has become smaller. When the input rotational speed Nin increases due to a downshift and NINT ^* −Nin <α ₃ , step Q10 is executed.
The time t _{4 in} FIG. 11 is the time when NINT ^* −Nin <α ₃ is satisfied and the determination in step Q9 is YES.
[0040]
In step Q10, the rotational speed obtained by adding the predetermined value alpha ₂ and sweep amount .DELTA.N the standard rotational speed nIN0 the (Nin0 + α ₂ + ΔN) is set to the target input rotational speed NINT ^*, the target input the target input rotational speed NINT ^* Shift control of the transmission 12 is performed in place of the rotational speed NINT. The sweep amount ΔN is added by a fixed amount every cycle, and the target input rotation speed NINT ^* is linearly increased at a predetermined rate of change. For this rate of change, for example, the accelerator operation amount θac, the original target input rotational speed NINT, and the like are set as parameters so as to moderately shift down while preventing the driving force from being reduced due to a sudden downshift. As the downshift is performed, the input rotational speed Nin increases substantially linearly. In step Q11, a rotational speed difference (NINT-NINT ^* ) obtained by subtracting the target input rotational speed NINT ^* from the original target input rotational speed NINT obtained from FIG. 7 using the accelerator operation amount θac and the vehicle speed V as parameters. It is determined whether or not the value is smaller than a predetermined value ε (for example, about several tens to 100 rpm), and step Q10 is repeated until NINT−NINT ^* <ε. Then, when NINT−NINT ^* <ε, this control is terminated, and the normal shift control based on the target input rotational speed NINT obtained from FIG. 7 is returned. The time t _{5 in} FIG. 11 is the time when NINT−NINT ^* <ε and the determination in step Q11 is YES.
[0041]
As described above, in this embodiment, the engine rotational speed Ne is synchronously rotated when switching from the “motor travel mode (forward)” in the engine stop state to the “direct travel mode” in which the engine 14 is driven as a drive source during vehicle travel. The target input rotational speed NINT ^* = Nin + α ₁ is set in step Q5 until the rotational speed (Nin + α ₁ ) slightly higher than the speed is exceeded, and the shift control of the transmission 12 is performed using the target input rotational speed NINT ^*. The gear ratio γ and the input rotational speed Nin are maintained substantially constant, the engine rotational speed Ne quickly reaches the synchronous rotational speed, the second clutch C2 is engaged, and the engine 14 is operated in the “direct running mode”. As a driving source, the mode switching time (time t _{1 to} t ₄ in FIG. 11) until the vehicle can travel with a large driving force is shortened.
[0042]
In this embodiment, the output of the motor generator 16 is controlled in accordance with the accelerator operation amount θac until the second clutch C2 is engaged, but the speed ratio γ is increased until the engine rotational speed Ne exceeds the rotational speed (Nin + α ₁ ). Since the input rotational speed Nin is maintained substantially constant, the motor rotational speed Nm that coincides with the input rotational speed Nin is also maintained substantially constant, and a torque decrease accompanying an increase in the motor rotational speed Nm is prevented. Even during the mode switching transition, the output control of the motor generator 16 can provide excellent driving force performance according to the driver's required output, and the noise (beat noise) of the motor generator 16 as the motor rotational speed Nm increases. Is prevented from increasing.
[0043]
As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention implements in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a hybrid drive control apparatus according to an embodiment of the present invention.
FIG. 2 is a skeleton diagram showing a power transmission system of the hybrid drive control 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 control device of FIG. 1 and the operating states of clutches and brakes. FIG.
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 travel mode, the direct travel mode, and the motor travel mode (forward) in FIG. 4;
FIG. 6 is a schematic view showing an entire drive device including a rear motor generator for driving rear wheels.
7 is a diagram for explaining an example of a map for calculating a target input rotation speed NINT in the shift control of the transmission performed by the T / MECU in FIG. 1. FIG.
FIG. 8 is a diagram for explaining an example of a map for calculating a required oil pressure in the transmission clamping pressure control performed by the T / MECU in FIG. 1;
FIG. 9 is a flowchart illustrating an operation when switching from “motor travel mode (forward)” to “direct travel mode” in the hybrid drive control device of FIG. 1;
FIG. 10 is a flowchart for explaining shift control of the transmission at the time of mode switching in FIG. 9;
11 is an example of a time chart for explaining changes in the operating state of each part at the time of mode switching in FIG. 9;
[Explanation of symbols]
10: Hybrid drive control device (vehicle drive control device) 12: Transmission 14: Engine (internal combustion engine, prime mover) 16: Motor generator (electric motor) 68: T / MECU C2: Second clutch (power intermittent mechanism) Nin : Input rotation speed (synchronous rotation speed) Ne: Engine rotation speed (motor engine rotation speed)
Step R2: Motor output increasing means Steps Q4, Q5: Downshift limiting means

Claims (1)

A power intermittent mechanism is provided between an internal combustion engine used as a prime mover and a transmission, and an electric motor capable of generating a driving force via the transmission is provided separately from the internal combustion engine, In a vehicle having a motor travel mode that travels using the electric motor while the power interrupting mechanism is shut off, and a prime mover travel mode that travels using the internal combustion engine by connecting the power interrupting mechanism ,
A drive control device when downshifting the transmission with with increasing the amount of output required by the driver during vehicle travel from the motor drive mode by connecting the power interrupting mechanism switches to the prime mover driving mode ,
Downshift limiting means for limiting a downshift of the transmission until the rotational speed of the internal combustion engine substantially coincides with a synchronous rotational speed corresponding to the input rotational speed of the transmission at the time of the mode switching ;
Motor output increasing means for increasing the output of the electric motor according to the driver's output request amount at the time of the mode switching;
The vehicle drive control apparatus characterized by having a.

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