JP2012116350A - Shift transmission controller of hybrid electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift transmission controller of a hybrid electric vehicle which suppresses an increase of a fuel consumption amount and a noise generation, due to an engine blowing-up control according to the situation where a preshift request of a second gear mechanism and a traveling mode switching request are generated in tandem.SOLUTION: The shift transmission controller stands by until a switching request of the traveling mode to a traveling to use both an engine and a motor is made, when the preshift request to an even-numbered gear mechanism G2 is made during a traveling only by the motor (S2, 4). When the connection request for the traveling mode is made (S6: Yes), an inner clutch C1 is connected, a driving power of the engine is increased, while a driving power of the motor 3 is being decreased to zero (S8, 10), the preshift is executed to the even-numbered gear mechanism G2, while an instantaneous interruption of driving force of the motor 3 is prevented (S12), and at the same time the switching of the traveling mode to use both the engine and the motor, is completed (S14).

Description

  The present invention relates to a shift control device for a hybrid electric vehicle. More specifically, the present invention relates to a dual clutch transmission capable of continuously transmitting power even at the time of shifting by switching to a predicted gear position in advance while transmitting power. The present invention relates to a shift control device for a hybrid electric vehicle including

  As a transmission mounted on a vehicle, a so-called parallel shaft type transmission in which a plurality of shift stages are configured between an input shaft and an output shaft provided in parallel is known. When switching gears in a parallel shaft type transmission, two gears cannot be selected at the same time on the same input shaft. After performing the operation, the gear setting operation for the next gear stage is performed.

However, when such a shift stage is switched, transmission of driving force from a power source such as an engine to the transmission is temporarily interrupted, so even if the driver steps on the accelerator pedal, There is a problem that driving force is not continuously transmitted and driving feeling is deteriorated.
Therefore, in order to solve such a problem, for example, a first gear mechanism that connects an inner clutch and an outer clutch arranged in an inner and outer double to the engine, respectively, and configures a plurality of shift stages in the inner clutch is provided. A so-called dual clutch transmission has been developed that is connected to the outer gear and connected to a second gear mechanism that forms a plurality of shift speeds.

  In this dual clutch type transmission, for example, when one of the gear stages of the first gear mechanism is selected and the driving force of the engine is transmitted via the inner clutch, the outer clutch is disengaged and the second clutch The driving force from the engine is not transmitted to the gear mechanism. At this time, the second gear mechanism switches in advance to the next predicted next gear position (hereinafter, this operation is referred to as pre-shift), and if there is a gear position switching instruction based on the shift map, the outer clutch By connecting the, the driving feeling is improved by continuously transmitting power to the drive wheels.

  This dual clutch transmission is also used in a parallel hybrid electric vehicle that can arbitrarily transmit the driving force of an engine and an electric motor to driving wheels. For example, in the hybrid electric vehicle described in Patent Document 1, an electric motor is disposed on the outer peripheral side of the outer clutch, and the driving force of the electric motor is transmitted to the second gear mechanism.

  In the dual clutch transmission configured as described above, when the electric motor travels alone, both the inner clutch and the outer clutch are disconnected, and one of the second gear mechanisms is selected. The driving force from the engine is not transmitted to either the first gear mechanism or the second gear mechanism, and the driving force of the electric motor is transmitted to the driving wheel side through the gear stage of the second gear mechanism.

JP 2009-035168 A

As described above, the dual clutch transmission provided in the hybrid electric vehicle has a structure in which the electric motor must be disposed on the output side of the outer clutch, and as a result, the driving force of the electric motor is always the second. It is transmitted to the gear mechanism.
In order to switch the second gear mechanism to the next gear position, it is necessary to execute gear-engaging operation and gear-releasing operation using a synchronizer. For these gear-engaging operation and gear-releasing operation, the second gear mechanism is used. It is necessary to interrupt the power transmission. For this reason, in the technique described in Patent Document 1, it is necessary to perform control for once reducing the driving force of the motor to 0 in order to interrupt the power transmission of the second gear mechanism when switching to the next shift stage.

However, since the vehicle is driven using only the driving force of the electric motor when the electric motor is traveling alone, the operation of the electric motor is resumed upon completion of gearing to the next gear stage when shifting the second gear mechanism. There is a problem that momentary interruption of the driving force occurs until the driving force is transmitted, and the driving force transmitted to the driving wheels temporarily disappears, causing the driver to feel uncomfortable.
Therefore, in view of such a problem, the inner clutch is connected during the shift of the second gear mechanism, and the driving force of the engine is transferred to the driving wheel side via the first gear mechanism instead of the interrupted driving force of the motor. It is possible to consider so-called torque compensation control in which momentary interruption of the driving force is prevented by transmitting to the motor.
Note that the instantaneous interruption of the driving force due to the speed change of the second gear mechanism occurs not only in the electric motor independent traveling but also in the engine / electric motor combined traveling. Therefore, the torque compensation control is also effective in such a case.

For example, when the electric motor alone cannot be continued due to a decrease in the remaining capacity (SOC) of the battery or the like, the running mode is switched from the electric motor alone to the electric motor / engine combined running. In such a case as well, an operation is performed in which the inner clutch is connected and the driving force of the engine is transmitted to the drive wheels via the first gear mechanism.
The inner clutch is connected at the time of switching the driving mode caused by the shift of the second gear mechanism (hereinafter referred to as a pre-shift) at the time of the above-described electric motor independent traveling or engine / electric motor combined traveling (hereinafter referred to as pre-shifting) and SOC reduction. Both require control to synchronize the rotation of the clutch input / output by blowing up the engine.

For example, FIG. 5 is a schematic diagram showing an operation sequence when there is a pre-shift request for the second gear mechanism G2 during traveling of the electric motor alone, followed by a request for switching the traveling mode due to a decrease in SOC, etc., in order from the top to the bottom. The operation is being performed, and the path during power transmission is indicated by a bold line, and the gears selected by the gear mechanisms G1 and G2 are circled. Further, in this example, the first gear mechanism G1 is configured by odd-numbered gears (1, 3, 5th gear), and the second gear mechanism G2 is configured by even-numbered gears (2, 4, 6th gear). Yes.
When the motor is traveling alone, the inner clutch C1 and the outer clutch C2 are both disconnected. For example, the second gear mechanism G2 selects the second speed, and the driving force of the motor 3 is transmitted to the drive wheel 14 via the second speed. The vehicle is traveling (the top row in the figure). When there is a pre-shift request from the second speed to the fourth speed, the inner clutch C1 is connected while the engine 1 is blown up and the rotation of the clutch input / output is synchronized (second stage in the figure).

Then, the driving force of the electric motor 3 is gradually reduced from the driver's required torque to 0, and the driving force of the engine 1 is increased from 0 to the required torque, so that the driving force of the engine 1 is increased, for example, by the first gear mechanism G1. Torque compensation control is performed by transmitting to the drive wheel 14 side via the third speed.
In this state, the second gear mechanism G2 performs the preshift from the second speed to the fourth speed, and after the preshift is completed, the driving force of the engine 1 is reduced to 0 again and the driving force of the electric motor 3 is increased to the required torque. Thus, the inner clutch C1 is disengaged and the electric motor alone travels through the fourth speed (third stage in the figure).

After that, when there is a request for switching the driving mode from single motor driving to engine / motor combined driving due to a decrease in SOC or the like, the inner clutch C1 is connected while the engine 1 is blown up again to synchronize the rotation, and the engine 1 driving force begins to be transmitted to the drive wheel 14 side via the first gear mechanism G1. The driving force of the electric motor 3 and the driving force of the engine 1 are adjusted to a predetermined ratio, for example, 50%, respectively, and the engine / electric motor combined running is started (the lowermost stage in the figure).
Therefore, in this case, the blow-up control of the engine 1 is executed twice during the pre-shift of the second gear mechanism G2 and when the traveling mode is switched.

FIG. 6 is a schematic diagram showing an operation sequence when there is a request for switching the running mode due to a decrease in SOC or the like, and then there is a pre-shift request for the second gear mechanism G2.
When there is a drive mode switching request to the engine / motor combined drive in the single motor drive (second stage in the figure) via the second speed, the inner clutch C1 is connected while the engine 1 is blown up and synchronized in rotation. Then, the driving force of the engine 1 starts to be transmitted to the driving wheel 14 side via the first gear mechanism G1. In parallel with this, the driving force of the electric motor 3 and the driving force of the engine 1 are adjusted to a predetermined ratio, for example, 50%, respectively, and the combined use of the engine and the electric motor is started (second stage in the figure).

Thereafter, when there is a pre-shift request from the second speed to the fourth speed, torque compensation control is executed to prevent instantaneous interruption of the driving force of the electric motor 3. At this time, since the inner clutch C1 is already connected, the driving force of the electric motor 3 is gradually reduced from the required torque to 0, and the driving force of the engine 1 is increased from 0 to the required torque (the three stages in the figure). Eye). In this case, the engine 1 does not blow up, but the driving power of the engine 1 is increased, so that the fuel consumption increases.
In this state, the second gear mechanism G2 performs a preshift from the second speed to the fourth speed, and after completion of the preshift, the driving force of the electric motor 3 and the driving force of the engine 1 are adjusted to, for example, 50% (see FIG. The bottom row in the middle).

Therefore, in this case, the engine 1 blow-up control is executed when the traveling mode is switched, and the engine drive force increase control is executed when the second gear mechanism is pre-shifted, although the engine 1 blow-up control is unnecessary. .
Since both the engine blow-up control and the engine driving force increase control consume excess fuel, it is a cause of deterioration in fuel consumption to execute such control in succession. Further, there is a problem that the noise caused by the continuous blow-up of the engine 1 causes discomfort to the occupant and can be annoying in residential areas.

  The present invention has been made to solve such a problem, and the object of the present invention is to make a request for pre-shift of the second gear mechanism and a request for switching the running mode due to a decrease in SOC, etc. while the motor is traveling alone. It is an object of the present invention to provide a shift control device for a hybrid electric vehicle that can suppress an increase in fuel consumption and noise generation due to engine blow-up control and engine drive force increase control according to this when they occur before and after. .

  In order to achieve the above object, a first aspect of the present invention provides a shift control for a hybrid electric vehicle in which an engine and an electric motor are connected via a clutch, and the driving force of the engine and the electric motor is transmitted to drive wheels via a transmission. In the apparatus, a transmission is connected to the engine via a first clutch, and a first transmission mechanism that shifts the driving force of the engine transmitted via the first clutch to a plurality of shift speeds and outputs it to the drive wheels. The motor is connected to the engine via the second clutch, and an electric motor is disposed on the output side of the second clutch, and the engine driving force transmitted through the second clutch and the driving force of the motor are changed to a plurality of speeds. And a second speed change mechanism that shifts the speed to the driving wheel and outputs it to the drive wheel. With the first clutch and the second clutch disengaged, the driver's request torque When there is a request to pre-shift the gear position of the second speed change mechanism to another gear speed while traveling with only the driving force of the electric motor according to the condition, the system waits until there is a request to connect the first clutch, When there is a connection request, the first clutch is connected, the driving force of the motor is reduced to 0, the driving force of the engine is increased to the required torque, and a first control means is provided for performing a preshift with respect to the second speed change mechanism. It is a thing.

  According to a second aspect of the present invention, in the shift control device for a hybrid electric vehicle in which the engine and the electric motor are connected via a clutch, and the driving force of the engine and the electric motor is transmitted to the drive wheels via the transmission, the transmission includes: A first speed change mechanism that is connected to the engine via the first clutch and that changes the driving force of the engine transmitted via the first clutch to a plurality of shift speeds and outputs it to the drive wheels; and via the second clutch The motor is connected to the engine, and an electric motor is disposed on the output side of the second clutch, and the driving force of the engine transmitted through the second clutch and the driving force of the electric motor are shifted to a plurality of shift stages to drive wheels. A second transmission mechanism that outputs to the motor, and with the first clutch and the second clutch disengaged, the driving force of the electric motor according to the torque required by the driver is determined by a predetermined gear position of the second transmission mechanism. When the first clutch connection request is made during traveling, the rotation speed of the motor is set in advance even if there is no request to pre-shift the gear position of the second speed change mechanism to the predetermined gear speed. The first clutch is connected on condition that the judgment value is 1 or more, the driving force of the motor is reduced to 0, the driving force of the engine is increased to the required torque, and the shift stage of the second transmission mechanism is preshifted. A second control means is provided.

  According to a third aspect of the present invention, in the first aspect, the first control means is a second determination value set in advance with the upshift line to the predetermined gear position after the preshift as an upper limit during the standby after the preshift request. When the rotation speed of the electric motor is reached, it is considered that the first clutch is requested to be connected.

As described above, according to the shift control device for a hybrid electric vehicle according to the first aspect of the present invention, when the second shift mechanism is requested to pre-shift to a predetermined shift stage while traveling only with the driving force of the electric motor. , Wait until there is a request for connection of the first clutch, that is, there is a request for switching the driving mode to engine independent traveling or engine / motor combined traveling by transmitting the driving force of the engine from the first clutch to the first transmission mechanism. When there is a request to connect the first clutch, the first clutch is connected, the driving force of the motor is reduced to 0 and the engine driving force is increased to prevent premature interruption of the driving force of the motor while pre-shifting the second speed change mechanism. Was made to run.
Therefore, the pre-shift of the second speed change mechanism and the switching of the driving mode can be executed simultaneously by connecting the first clutch once, and the engine blow-up control for synchronizing the rotation when the first clutch is connected is executed only once. Therefore, increase in fuel consumption and noise generation by the engine blow-up control can be suppressed.

According to the shift control device for a hybrid electric vehicle of the second aspect of the present invention, the first clutch connection request, that is, the engine driving force is transmitted from the first clutch to the first transmission mechanism while the vehicle is running only with the driving force of the electric motor. Even when there is a request for switching the driving mode to engine independent traveling or engine / motor combined traveling, there is no pre-shift request to the predetermined gear position for the second transmission mechanism, and the rotational speed of the motor The first clutch is connected on the condition that is equal to or greater than the first determination value, and the driving force of the motor is reduced to 0 and the engine driving force is increased to prevent the motor driving force from being momentarily interrupted. The pre-shift for the two speed change mechanism is executed.
Therefore, the pre-shift of the second speed change mechanism and the switching of the driving mode can be executed simultaneously by connecting the first clutch once, and the engine blow-up control for synchronizing the rotation when the first clutch is connected is executed only once. Therefore, increase in fuel consumption and noise generation by the engine blow-up control can be suppressed. In addition, since the pre-shift is performed by connecting the first clutch when the rotation speed of the motor is equal to or higher than the first determination value, it is possible to prevent a situation in which the rotation speed of the motor suddenly drops after the shift up and the driver feels uncomfortable. can do.

  According to the shift control device for a hybrid electric vehicle of the invention of claim 3, in addition to claim 1, during the standby after the pre-shift request, the rotation speed of the motor is set to the upper limit of the upshift line to the predetermined gear stage. When the determination value of 2 is reached, it is assumed that the first clutch is requested to be connected. Therefore, it is possible to reliably prevent a malfunction when the switching of the driving mode due to the execution of the preshift and the subsequent connection of the first clutch is excessively delayed.

1 is an overall configuration diagram illustrating a shift control device for a hybrid electric vehicle according to an embodiment. It is a flowchart which shows the pre-shift / travel mode control routine which ECU of 1st Embodiment performs. It is a schematic diagram which shows the operation | movement order based on the pre-shift and driving mode control routine of 1st and 2nd embodiment. It is a flowchart which shows the pre-shift / travel mode control routine which ECU of 2nd Embodiment performs. It is a schematic diagram which shows the operation | movement order by the prior art corresponding to 1st Embodiment. It is a schematic diagram which shows the operation | movement order by the prior art corresponding to 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of a shift control apparatus for a hybrid electric vehicle embodying the present invention will be described.
FIG. 1 is an overall configuration diagram showing a shift control apparatus for a hybrid electric vehicle according to the present embodiment. A vehicle is equipped with a diesel engine (hereinafter referred to as an engine) 1 as a driving power source. The engine 1 is configured as a so-called common rail type engine that supplies high-pressure fuel accumulated in a common rail by a pressurizing pump to the fuel injection valve of each cylinder and injects the fuel into the cylinder as the fuel injection valve opens.

An output shaft 1a of the engine 1 protrudes rearward of the vehicle (rightward in the figure) and is connected to an input shaft 2a of an automatic transmission (hereinafter simply referred to as a transmission) 2. The transmission 2 has six forward speeds (first speed to sixth speed) and one reverse speed. After the power of the engine 1 is input to the transmission 2 via the input shaft 2a, the transmission 2 according to the gear speed. The speed is changed and transmitted from the output shaft 2 b to the left and right drive wheels 14 via the differential 12 and the drive shaft 13.
Needless to say, the gear position of the transmission 2 is not limited to the above and can be arbitrarily changed.

The transmission 2 is configured as a so-called dual clutch transmission, and includes an electric motor 3 as a driving power source. The details of the dual clutch transmission are described in, for example, Japanese Patent Application Laid-Open No. 2009-035168, and therefore only a brief description is given in the present embodiment. For this reason, FIG. 1 shows the transmission 2 in a schematic representation different from the actual mechanism, and the configuration and operating state of the transmission 2 will also be conceptually described in the following description.
As is well known, a dual clutch type transmission is provided with an odd-numbered gear stage and an even-numbered gear stage as mutually independent power transmission systems, and when one of them is transmitting power, the other is predicted next. By switching to the gear in advance, the system completes the switch to the next gear without interrupting power transmission.

That is, as shown in FIG. 1, the input shaft 2a of the transmission 2 is connected to the odd-numbered gear mechanism G1 (first shift speed) including the odd-numbered shift speeds (1, 3, and 5 speed stages) via the clutch C1 (first clutch). Is connected to the input shaft 2a, and an even gear mechanism G2 (second speed change mechanism) comprising even speed steps (2, 4, 6th speed) via a clutch C2 (second clutch) and an electric motor 3 is connected to the input shaft 2a. ) Is connected. The output sides of these gear mechanisms G1 and G2 are connected to the common output shaft 2b.
In FIG. 1, the reverse gear is omitted for convenience of explanation.

Although not shown, the electric motor 3 is composed of a rotor and a stator that are disposed in two layers, and a rotating shaft that rotatably supports the rotor is connected to the output side of the clutch C2. A battery 5 for traveling is electrically connected to the electric motor 3 via an inverter 4, and power running control and regenerative control of the electric motor 3 are performed by the inverter 4 as will be described later. That is, in the power running control, the DC power stored in the battery 5 is converted into AC power by the inverter 4 and supplied to the electric motor 3, and the electric motor 3 operates as a motor to input the driving force to the even gear mechanism G2.
In the regenerative control during vehicle deceleration, the electric motor 3 operates as a generator by reverse driving from the drive wheel side to generate a regenerative braking force, and the generated AC power is converted into DC power by the inverter 4 to be supplied to the battery 5. Is charged.

Here, in order to improve the space efficiency in the transmission 2, both the clutches C1 and C2 are double-sided with the clutch C1 on the odd speed side set as the inner peripheral side and the clutch C2 on the even speed stage side set as the outer peripheral side. It is arranged. Therefore, in the following description, the odd-numbered speed side clutch C1 is referred to as an inner clutch, and the even-numbered speed side clutch C2 is referred to as an outer clutch.
A hydraulic cylinder 6 is connected to each of the inner clutch C1 and the outer clutch C2, and both the hydraulic cylinders 6 are connected to a hydraulic pressure supply source 9 through an oil passage 8 in which an electromagnetic valve 7 is interposed. When the solenoid valve 7 is opened, the hydraulic oil is supplied from the hydraulic supply source 9 to the hydraulic cylinder 6 through the oil passage 8, and the hydraulic cylinder 6 is operated to switch the corresponding clutch C1, C2 from the connected state to the disconnected state. .
On the other hand, when the solenoid valve 7 is closed, the hydraulic cylinder 6 does not operate due to the supply of hydraulic oil being stopped, so that the clutches C1 and C2 are switched from a disconnected state to a connected state by a pressure spring (not shown).
The driving method of the clutches C1 and C2 is not limited to this, and for example, air driving may be adopted instead of hydraulic driving.

  The odd-numbered gear mechanism G1 and the even-numbered gear mechanism G2 of the transmission 2 are each provided with a gear shift unit 10. Although not shown, the gear shift unit 10 incorporates a plurality of hydraulic cylinders that operate shift forks corresponding to the respective shift speeds in the gear mechanisms G1 and G2, and a plurality of electromagnetic valves that operate each hydraulic cylinder. The gear shift unit 10 is connected to the above-described hydraulic pressure supply source 9 via an oil passage 11, and hydraulic oil from the hydraulic pressure supply source 9 corresponds to each opening and closing of each electromagnetic valve (not shown). When the hydraulic cylinder is operated and the shift fork is switched, the gear stages of the corresponding gear mechanisms G1 and G2 are switched according to the switching operation.

In the passenger compartment, an input / output device (not shown), a storage device (ROM, RAM, etc.) for storing control programs and control maps, an ECU (control unit) equipped with a central processing unit (CPU), a timer counter, etc. 21 is installed, and comprehensive control of the engine 1, the transmission 2, the electric motor 3, the inner clutch C1, and the outer clutch C2 is performed.
On the input side of the ECU 21, an engine rotation speed sensor 22 that detects the rotation speed Ne of the engine 1, an inner clutch rotation speed sensor 23 that detects the rotation speed Nc1 on the output side of the inner clutch C1, and a rotation on the output side of the outer clutch C2 An outer clutch rotational speed sensor 24 for detecting the speed Nc2 (= the rotational speed of the electric motor 3), a gear position sensor 25 for detecting the gear position of the gear mechanisms G1 and G2, and an accelerator sensor 27 for detecting the opening degree θacc of the accelerator pedal 26; Sensors such as a vehicle speed sensor 28 provided on the output shaft 2b of the transmission 2 and detecting the vehicle speed V are connected.

  The output side of the ECU 21 is connected to the inverter 4, the electromagnetic valves 7 of the clutches C1 and C2, the electromagnetic valves of the gear shift unit 10, and the like. The fuel injection valve of each cylinder is connected. In addition, you may make it provide ECU for engine control separately from ECU21, for example, without controlling comprehensively by single ECU21 in this way.

  Then, based on detection information such as the accelerator opening θacc detected by the accelerator sensor 27 and the vehicle speed V detected by the vehicle speed sensor 28, the ECU 21 sets the driver's required torque to a positive value during vehicle acceleration or constant speed driving. Is calculated as a negative value when the vehicle decelerates. Then, based on the obtained required torque, the running state of the vehicle, the operating state of the engine 1 and the electric motor 3, or the remaining capacity (SOC: State Of Charge) of the battery 5 or the like, the running mode (engine alone running, motor alone running, engine The motor 1 and the electric motor 3 are operated to achieve the required torque based on the selected driving mode, and the shift control of the transmission 2 is appropriately executed.

For example, when the SOC of the battery 5 is extremely lowered and normal operation of the electric motor 3 cannot be expected (low SOC state), the engine single traveling is selected as the traveling mode.
In the engine traveling alone, by connecting either the inner clutch C1 or the outer clutch C2, the driving force of the engine 1 is supplied to the driving wheel 14 side via the gear stage of the corresponding gear mechanism G1, G2. To the vehicle to drive the vehicle. Also, if the engine 1 has more margin at this time, the electric motor 3 is operated as a generator to charge the generated electric power to the battery 5 and at the time of vehicle deceleration, the regenerative electric power from the electric motor 3 is charged to the battery 5 to recover the SOC. Plan.

  The shift control is executed based on the target shift speed obtained from a predetermined shift map, but prior to the shift to the target shift speed, switching to the next shift speed predicted from the acceleration / deceleration of the vehicle or the like is performed (hereinafter referred to as this shift speed). The operation is called pre-shift). For example, at the time of vehicle acceleration, a gear mechanism on which the high gear side adjacent to the current gear stage during power transmission is predicted as the next gear stage, and the power transmission is interrupted based on a pre-shift request to the next gear stage. G1 or G2 is switched to the next shift stage in advance.

After that, when the vehicle speed V that is increasing with the acceleration of the vehicle crosses the upshift line to the next shift stage on the shift map, the target shift stage is changed from the current shift stage to the next shift stage, and then the clutch C1, The target shift speed is achieved by reversing the connection / disconnection state of C2. Thus, by completing the switching to the next shift stage by the pre-shift in advance, the shift is completed without interrupting the power transmission only by reversing the connection / disconnection state of the clutches C1 and C2.
Further, in the engine control at this time, the driving force to be output by the engine 1 is calculated from the driver's required torque in consideration of the gear stage during power transmission, and the fuel injection amount and the fuel are calculated based on the calculated driving force. Control injection timing.

On the other hand, when the SOC of the battery 5 is less than the predetermined value and there is not much room (medium SOC state), or when the required torque is greater than or equal to the predetermined value, the engine / motor combined travel is selected.
In the engine / motor combined driving, as in the engine independent driving, either the inner clutch C1 or the outer clutch C2 is connected to transmit the driving force of the engine 1 to the drive wheel 14 side, and at the same time, the motor 3 is used as a motor. Operate. Thus, when the inner clutch C1 is connected, the driving force of the engine 1 transmitted through the odd-numbered gear mechanism G1 and the driving force of the motor 3 transmitted through the even-numbered gear mechanism G2 merge and then the driving wheel 14 side When the outer clutch C2 is connected, both the driving force of the engine 1 and the driving force of the electric motor 3 are transmitted to the driving wheel 14 side through the even gear mechanism G2.

  Although details will not be described, in this case as well, the shift to the target shift stage is performed based on the shift map after performing the pre-shift to the shift stage. Further, in this case, since the driver's required torque is achieved by the driving force of the engine 1 and the electric motor 3, the required torque is allocated to the engine 1 side and the electric motor 3 side, and the gear position is changed based on the individual required torque. In consideration of the above, the driving force to be output by each is calculated and the engine control and the control of the electric motor 3 are executed.

On the other hand, for example, when the SOC of the battery 5 is greater than or equal to a predetermined value and the margin is high (high SOC state), and the driver's required torque is less than the predetermined value, the motor independent traveling is selected as the traveling mode.
In the electric motor traveling alone, the inner clutch C1 and the outer clutch C2 are both disconnected, and the electric motor 3 is operated as a motor. As a result, the driving force of the electric motor 3 is transmitted to the driving wheel 14 side through any of the gear stages of the even gear mechanism G2. At this time, the engine 1 is kept in idle operation. However, the present invention is not limited to this, and the engine 1 may be temporarily stopped during the electric motor traveling alone.

In this way, since it is impossible to travel through the gears of the odd-numbered gear mechanism G1 when the motor is traveling alone, the region of the odd-numbered gears on the shift map is replaced by the even-numbered gears. It is necessary to achieve the required torque similar to that in the case of the odd-numbered shift stage by the power transmission through the stage. Therefore, the second speed is selected instead of the first speed for the area where the first speed on the shift map is to transmit power (the area of the required torque and the vehicle speed V where the first speed is set based on the shift map).
In addition, the region where the third speed should transmit power is divided into the low speed gear side and the high speed gear side with a predetermined switching point as a boundary, and then the second speed is set instead of the third speed in the low speed gear side region. In the region on the high speed gear side, the fourth speed is selected instead of the third speed. Similarly, in the region where the fifth speed should transmit power, the fourth speed is selected instead of the fifth speed in the region on the low speed gear side with the predetermined switching point as a boundary, and the fifth speed is replaced in the region on the high speed gear side. To select 6th speed. The switching point may be set at the center of the region, or may be set at a position offset to the low gear side or the high gear side.

As a result, in the electric motor alone traveling, the switching between the even gear position on the low speed gear side and the even gear position on the high speed gear side is performed at the switching point of each odd gear stage, so that the second speed, The gears are switched in the order of sixth speed, fourth speed, and second speed at the time of downshifting in the order of speed and sixth speed.
In the odd-numbered gear range on the shift map, the driving force of the electric motor 3 is controlled so that the required torque to be achieved at this time is achieved at the even-numbered gear. Specifically, when the even-numbered gear on the low-speed gear side is selected in each odd-numbered gear region, the driving force of the motor 3 is controlled in a decreasing direction, and when the even-numbered gear on the high-speed gear is selected. The driving force of the electric motor 3 is controlled in the increasing direction.

By the way, in order to switch the even gear mechanism G2 to the next gear stage based on the shift map in the electric motor alone controlled as described above, the even gear mechanism is used to execute the gear insertion operation and the gear release operation using the synchronization device. It is necessary to interrupt the power transmission of G2, and for this reason, once the driving force of the electric motor 3 is reduced to 0, an instantaneous interruption of the driving force occurs until the operation of the electric motor 3 is resumed due to the completion of shifting. End up.
As a countermeasure, in this embodiment, the inner clutch C1 is connected during the upshifting of the even gear mechanism G2, and the driving force of the engine 1 is driven via the odd gear mechanism G1 instead of the interrupted driving force of the motor 3. A so-called torque compensation control is performed to prevent momentary interruption of the driving force by transmitting to the wheel 14 side.

Note that even if a momentary interruption of the driving force occurs during deceleration of the vehicle, the driver does not feel uncomfortable, so torque compensation control is not executed during downshifting. However, similar torque compensation control may be executed at the time of downshifting in addition to at the time of upshifting.
The shift of the even gear mechanism G2 is different in purpose from the above-described pre-shift at the normal shift, but the even gear mechanism G2 is set to the next shift stage in advance during power transmission via the odd gear mechanism G1. The operation order is the same in terms of switching. Therefore, the shifting operation executed by the even gear mechanism G2 during the torque compensation control is also referred to as pre-shift in the following description.

In addition, in the independent traveling of the electric motor, the odd-numbered gear mechanism G1 does not affect the traveling at any gear stage, but torque compensation control for compensating the driving force that should be originally generated by the electric motor 3 by the driving force of the engine 1. In view of the spirit, the gear stage between the gear stages before and after the pre-shift is selected by the odd-numbered gear mechanism G1. For example, the third speed is selected by the odd-numbered gear mechanism G1 when pre-shifting from the second speed to the fourth speed, and the fifth speed is selected by the odd-numbered gear mechanism G1 when pre-shifting from the fourth speed to the sixth speed.
On the other hand, when the SOC of the battery 5 decreases due to continuing the motor alone, or when the required torque cannot be achieved with the torque generated by the motor 3 as the accelerator is depressed, the ECU 21 considers that the motor alone cannot be continued. Switch the drive mode to engine / motor combined drive.

Even when the driving mode is switched from the electric motor single traveling to the engine / motor combined traveling (hereinafter sometimes simply referred to as “traveling mode switching”), the inner clutch C1 is connected to connect the odd gear mechanism G1. Thus, an operation for transmitting the driving force of the engine 1 to the drive wheel 14 side is performed.
As described above, since the engine 1 when the motor is traveling alone is in an idling operation, the inner clutch C1 can be connected when the traveling mode is switched due to the pre-shift of the even gear mechanism G2 or the decrease in the SOC. As described in [Problems to be Solved by the Invention], it is necessary to control the engine 1 to blow up or to increase the engine driving force, which causes a problem of increasing fuel consumption.

Therefore, in this embodiment, when there is a pre-shift request during traveling alone of the motor, and there is a request for switching the traveling mode due to a decrease in SOC or the like thereafter, an opportunity to increase fuel consumption by executing these processes simultaneously. Measures to be taken are taken, and the processing executed by the ECU 21 for the measures will be described in detail below.
FIG. 2 is a flowchart showing a pre-shift / travel mode control routine executed by the ECU 21, and FIG. 3 is a diagram when the engine 1, the motor 3, the clutches C1, C2 and the gear mechanisms G1, G2 are switched based on the pre-shift / travel mode control routine. It is a schematic diagram which shows an operation | movement order. In FIG. 3, the operation is performed in order from the upper stage to the lower stage, and the path during power transmission is indicated by a thick line, and the gear stage selected by each gear mechanism is marked with a circle. In the present embodiment, the ECU 21 when executing the routine of FIG. 2 functions as the first control means.

First, in step S2, it is determined whether or not the motor is traveling alone, and if the determination is No (No), the routine is once terminated. Further, when it is determined that the motor is traveling alone (Yes) in step S2, the process proceeds to step S4. As shown in the upper part of FIG. 3, the inner clutch C1 and the outer clutch C2 are both disengaged when the motor is traveling alone. For example, the even speed gear mechanism G2 selects the second speed, and the driving force of the motor 3 via the second speed. Is transmitted to the drive wheel 14 side, so that the vehicle travels while achieving the torque required by the driver.
As described above, the second speed is also selected on the low-speed gear side from the switching point in the third speed region that is an odd speed stage, and in this region, the motor 3 is driven so as to achieve the required torque corresponding to the third speed. Force is controlled. Note that the engine 1 while the electric motor is traveling alone is maintained in idle operation, and the third speed is selected in the odd-numbered gear mechanism G1.

In step S4, it is determined whether or not a pre-shift on the upshift side is requested for the even gear mechanism G2. If the determination is No, the routine is terminated. The determination in step S4 according to the pre-shift request on the upshift side (either the second speed to the fourth speed or the fourth speed to the sixth speed, but the case of the second speed to the fourth speed will be exemplified below). If YES, it is determined in step S6 whether or not switching of the driving mode from single motor driving to engine / motor combined driving is requested due to a decrease in SOC or the like, and the processing in step S6 is repeated for No. And wait.
When the determination in step S6 is Yes due to the travel mode switching request, the inner clutch C1 is connected in step S8. The clutch connection at this time is performed while blowing up the engine 1 and synchronizing the rotation of the clutch input / output. In the subsequent step S10, the driving force of the electric motor 3 is gradually reduced from the required torque to 0, and the driving force of the engine 1 is increased from 0 to the required torque.

Torque compensation control is performed by the above processing, and as shown in the middle part of FIG. 3, the driving force of the engine 1 is transferred to the driving wheel 14 side via the odd-numbered gear mechanism G1 instead of the interrupted driving force of the electric motor 3. By being transmitted, momentary interruption of the driving force is prevented.
In step S12, the even gear mechanism G2 performs a pre-shift from the second speed to the fourth speed. When the pre-shift is completed, the process proceeds to step S14, where the driving force of the motor 3 and the driving force of the engine 1 are set at a predetermined ratio, for example, Allocate 50% for each adjustment. As a result, as shown in the lower part of FIG. 3, the driving force of the electric motor 3 is transmitted to the driving wheel 14 side via the pre-shifted fourth speed, and the engine / electric motor combined running is started.

  Here, it waits without executing the pre-shift until the travel mode switching request, but it does not wait indefinitely. That is, the driving mode switching request is performed not only when the SCO of the battery 5 is lowered but also when the required torque cannot be achieved by the torque generated by the electric motor 3. For this reason, when the pre-shift execution is delayed and the rotational speed (= Nc2) of the electric motor 3 increases, the driving force of the electric motor 3 gradually decreases according to the torque curve, and the required torque cannot be achieved, and the engine / electric motor combined driving is automatically performed. The travel mode switching request is made. For this reason, it is prevented that execution of the preshift and subsequent switching of the driving mode are delayed to an inappropriate timing.

As described above, in the present embodiment, when there is a pre-shift request for the even gear mechanism G2 during traveling alone of the electric motor, and there is a request for switching the travel mode due to a decrease in SOC or the like thereafter, execution of the pre-shift according to the pre-shift request is performed. By waiting until the switch request is made, the pre-shift of the even gear mechanism G2 and the switching of the running mode are simultaneously performed by connecting the inner clutch C1 once.
For this reason, it is only necessary to execute the blow-up control of the engine 1 for rotational synchronization when the inner clutch is connected. The engine blow-up control causes an increase in fuel consumption and noise generation, but since the number of times can be reduced, an excellent effect that increase in fuel consumption and noise generation can be suppressed can be obtained.

By the way, as described above, the standby pre-shift is naturally executed based on the request for switching the travel mode in which it is determined that the required torque cannot be achieved, but more reliable countermeasures can be implemented.
For example, during the pre-shift standby, the outer clutch rotational speed Nc2 is monitored, and during the pre-shift from the second speed to the fourth speed, the shift up line to the fourth speed on the shift map is set as the upper limit. When the outer clutch rotational speed Nc2 reaches the second determination value Nb, the travel mode switching request may be forcibly made.
With this configuration, the required torque according to the accelerator operation cannot be achieved due to problems when the pre-shift execution and the subsequent switching of the driving mode are excessively delayed, for example, the delay of the upshifting or the continuation of the electric motor alone. It is possible to reliably prevent problems such as falling into the process.

[Second Embodiment]
Next, a second embodiment in which the present invention is embodied in another shift control device for a hybrid electric vehicle will be described.
The overall configuration of the speed change control device of this embodiment is the same as that of the first embodiment shown in FIG. The difference is that, in the first embodiment, it is assumed that there is a pre-shift request during motor traveling alone, and then there is a request for switching the traveling mode, whereas in this embodiment, switching of the traveling mode is performed during motor traveling alone. This is to implement a measure assuming that there is a request and then a pre-shift request.
Therefore, the ECU 21 of the present embodiment executes the flowchart of FIG. 4 instead of the flowchart of FIG. 2 described in the first embodiment. The operation sequence based on the preshift / travel mode control routine of FIG. 4 is not different from that of FIG. 3 used in the first embodiment, and will be described with reference to FIG. In this embodiment, ECU21 when performing the routine of FIG. 4 functions as a 2nd control means.

First, in step S22, it is determined whether or not the motor is traveling alone. When the determination is No, the routine is terminated, and when the determination is Yes, the process proceeds to step S24. As shown in the upper part of FIG. 3, the vehicle at this time travels alone while the driving force of the motor 3 is transmitted to the drive wheels 14 via the second speed of the even gear mechanism G2.
In step S24, it is determined whether or not switching of the traveling mode from the motor single traveling to the engine / motor combined traveling is requested due to a decrease in the SOC or the like. When the travel mode switching request is made and the determination in step S24 is Yes, whether or not the clutch rotational speed Nc2 detected by the outer clutch rotational speed sensor 24 in step S26 is equal to or higher than the first determination value Na set in advance. Determine whether.

As described below, in the present embodiment, the pre-shift timing of the even-numbered gear mechanism G2 that should be executed later than the switching of the traveling mode (hereinafter, the case of the second to fourth speeds will be exemplified). The drive mode switching timing is advanced. For this reason, when the pre-shift timing is excessively advanced, the rotation speed of the electric motor 3 is not increased sufficiently, and the up-shifting is performed, and the rotation speed of the electric motor 3 after the up-shifting is below the effective torque range. This gives the driver a sense of stall. Therefore, the first determination value Na is set to a value that allows a reduction in rotation of the electric motor 3 after the upshift from the second speed to the fourth speed.
When the determination in step S26 is No, the routine is terminated, and when the clutch rotational speed Nc2 increases as the vehicle accelerates and the determination in step S26 becomes Yes, the routine proceeds to step S28. In step S28, the inner clutch C1 is connected while the engine 1 is blown up and the rotation of the clutch input / output is synchronized.

In the subsequent step S30, the driving force of the electric motor 3 is gradually decreased from the required torque to 0, and the driving force of the engine 1 is increased from 0 to the required torque. Torque compensation control is performed by the above processing, and as shown in the middle part of FIG. 3, the driving force of the engine 1 is transferred to the driving wheel 14 side via the odd-numbered gear mechanism G1 instead of the interrupted driving force of the electric motor 3. By being transmitted, momentary interruption of the driving force is prevented.
Thereafter, in step S32, a pre-shift from the second speed to the fourth speed is executed by the even gear mechanism G2, and when the pre-shift is completed, the process proceeds to step S34, where the driving force of the electric motor 3 and the driving force of the engine 1 are, for example, Allocate to 50% and adjust. As a result, as shown in the lower part of FIG. 3, the driving force of the electric motor 3 is transmitted to the driving wheel 14 side via the pre-shifted fourth speed, and the engine / electric motor combined running is started.

As described above, in the present embodiment, when there is a request for switching the driving mode while the motor is traveling alone, and there is a pre-shift request thereafter, when the clutch rotational speed Nc2 is less than the first determination value Na and it is possible to shift up without any trouble. By accelerating the execution of the pre-shift according to the pre-shift request until the request for switching the traveling mode, the switching of the traveling mode and the pre-shifting of the even gear mechanism G2 are simultaneously performed by connecting the inner clutch C1 once.
For this reason, it is only necessary to execute the blow-up control of the engine 1 for rotation synchronization when the inner clutch is connected, and it is possible to suppress the increase in fuel consumption and noise generation due to the engine blow-up control.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the transmission 3 is implemented as the forward six-speed transmission 3, but the number of the shift speed is not limited to this, and can be arbitrarily changed.
Further, the configuration of the transmission 3 such as the shift speeds constituting the odd-numbered gear mechanism G1 and the even-numbered gear mechanism G2, the arrangement of the respective shift speeds, and the shift speed switching mechanism at each shift speed are also the same as those in the above embodiment. It is not limited, and can be changed according to the driving performance and merchandise required for the hybrid electric vehicle.

Further, in the above embodiment, the inner clutch C1 and the outer clutch C2 are disposed in an inner and outer double, but the present invention is not limited to this, and both the clutches C1 and C2 may be provided side by side.
In the above embodiment, the first clutch connection request is assumed to be a request for switching the driving mode from the motor independent traveling to the engine / motor combined traveling. However, the present invention is not limited to this. It may be a request for switching the traveling mode to the individual traveling.
Also, the routine of FIG. 2 described in the first embodiment and the routine of FIG. 3 described in the second embodiment may be executed together.

DESCRIPTION OF SYMBOLS 1 Engine 2 Transmission 3 Electric motor 21 ECU (1st control means, 2nd control means)
G1 Odd gear mechanism (first transmission mechanism)
G2 Even gear mechanism (second transmission mechanism)
C1 Inner clutch (first clutch)
C2 Outer clutch (second clutch)

Claims (3)

In a shift control device for a hybrid electric vehicle in which an engine and an electric motor are connected via a clutch, and the driving force of the engine and the electric motor is transmitted to driving wheels via a transmission,
The above transmission is
A first speed change mechanism that is connected to the engine via a first clutch and that shifts the driving force of the engine transmitted via the first clutch to a plurality of shift speeds and outputs it to the drive wheels;
The motor is connected to the engine via a second clutch, and an electric motor is disposed on the output side of the second clutch. The engine driving force transmitted through the second clutch and the driving force of the motor are A second speed change mechanism that shifts to a plurality of shift speeds and outputs the speed to the drive wheel,
While the first clutch and the second clutch are disengaged, the second speed change mechanism while the vehicle is traveling with only the driving force of the electric motor according to the torque required by the driver by any one of the gear positions of the second speed change mechanism. When there is a request to pre-shift the shift stage to another shift stage, it waits until there is a connection request for the first clutch, and when there is a connection request for the first clutch, the first clutch is connected, A hybrid electric vehicle comprising: a first control means for pre-shifting the second transmission mechanism by reducing the driving force of the engine to 0 and increasing the driving force of the engine to the required torque. Shift control device. In a shift control device for a hybrid electric vehicle in which an engine and an electric motor are connected via a clutch, and the driving force of the engine and the electric motor is transmitted to driving wheels via a transmission,
The above transmission is
A first speed change mechanism that is connected to the engine via a first clutch and that shifts the driving force of the engine transmitted via the first clutch to a plurality of shift speeds and outputs it to the drive wheels;
The motor is connected to the engine via a second clutch, and an electric motor is disposed on the output side of the second clutch. The engine driving force transmitted through the second clutch and the driving force of the motor are A second speed change mechanism that shifts to a plurality of shift speeds and outputs the speed to the drive wheel,
While the first clutch and the second clutch are disengaged, the first clutch is connected while the vehicle is running only with the driving force of the motor according to the torque required by the driver by a predetermined gear position of the second transmission mechanism. When there is a request, the rotation speed of the electric motor is equal to or higher than a preset first determination value even when there is no request to pre-shift the shift stage of the second transmission mechanism to a predetermined shift stage. The first clutch is connected on the condition that the driving force of the electric motor is reduced to 0 and the driving force of the engine is increased to the required torque to pre-shift the second speed change mechanism. A shift control apparatus for a hybrid electric vehicle, comprising a control means.   In the standby after the pre-shift request, the first control means has reached the rotation speed of the electric motor at a second determination value set in advance with the up-shift line to the predetermined gear stage after the pre-shift as an upper limit. 2. The shift control apparatus for a hybrid electric vehicle according to claim 1, wherein it is considered that there is a request for connection of the first clutch.

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