JP2014124989A - Drive device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive device for a hybrid vehicle which can reduce the connection time of a front clutch when an engine is started and connected to an automatic transmission while the vehicle is traveling only by a motor.SOLUTION: A drive device for a hybrid vehicle includes: a mode determination section 10 for determining transition conditions from an electric travel mode to a split travel mode; a gear shift stage determination section 10 for determining a gear shift stage in an automatic transmission 8 and outputting a gear shift request for the gear shift of the automatic transmission 8; an output member rotational speed calculation section 10 for calculating an output member rotational speed after the gear shift which is the rotational speed of an output member 52 in a state in which the automatic transmission 8 is shifted to the gear shift stage according to the gear shift request; and an engine control section 10 for controlling the rotational speed of an engine 2 so that the rotational speed of an input member 51 becomes equal to the output member rotational speed when the mode determination section 10 determines that the transition conditions to the split travel mode are satisfied, and when the gear shift to the gear shift stage in the automatic transmission 8 according to the gear shift request is not completed.

Description

  The present invention relates to a drive device for a hybrid vehicle in which wheels are driven by an engine and a motor.

  There is a conventional technique related to a drive device for a hybrid vehicle in which wheels are driven by an engine and a motor generator (see, for example, Patent Document 1). In the drive device for a hybrid vehicle disclosed in Patent Document 1, an engine, a front clutch, an automatic transmission, and a motor generator are connected in series to enable the vehicle to travel using both the engine and the motor generator.

  In the driving device shown in Patent Document 1, for example, when the vehicle starts from a stopped state, the driving wheel is driven by a motor generator, and when accelerating during traveling, a front clutch is connected, The driving force of the engine is applied to the driving wheels.

  When the engine is started, the rotational speed of the engine rapidly increases due to the air present in the intake manifold. Therefore, Patent Document 1 discloses that when the engine is started and connected to the automatic transmission while the vehicle is traveling with the driving force of only the motor, the automatic shift is performed when the rotational speed of the engine rapidly increases at the start. By performing a downshift in the machine, the rotational speed of the input shaft of the automatic transmission does not fall below a predetermined value, the differential rotational speed of the input shaft and the engine is reduced, and the front clutch is quickly connected, A technique capable of suppressing deterioration of drivability due to clutch connection delay or shock is disclosed.

JP 2011-73483 A

  However, if the shift request is output and the automatic transmission shifts when the front clutch described above is engaged, the rotation speed of the motor generator and the rotation speed of the output shaft of the engine deviate due to the shift of the automatic transmission. End up. Then, the synchronization of the front clutch described above takes a long time, and as a result, a problem occurs that the front clutch is connected for a long time. Further, since the front clutch is connected for a long time, the engine consumes fuel unnecessarily, resulting in a problem that the fuel efficiency of the hybrid vehicle is deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to shorten the connection time of the front clutch when the engine is started and connected to the automatic transmission while the vehicle is traveling only by the motor. An object of the present invention is to provide a hybrid vehicle drive device capable of achieving the above.

  The present invention made in order to solve the above-described problems includes an engine that applies driving force to driving wheels, a motor that is provided between the engine and the driving wheels, and applies driving force to the driving wheels, A front side provided between the engine and the motor and having an input member that is rotationally connected to the engine and an output member that is rotationally connected to the motor, and connects or disconnects the input member and the output member A clutch, an input shaft that is provided between the front clutch and the drive wheel and rotates in conjunction with the output member; and an output shaft that rotates in conjunction with the drive wheel; An automatic transmission that selectively shifts a plurality of shift stages having different gear ratios obtained by dividing the rotation speed by the rotation speed of the output shaft, and the front clutch is connected to the input member and the front It is possible to switch between an electric travel mode in which the output member is disconnected and travels only with the driving force of the motor, and a split travel mode in which the input member and the output member are connected to travel with the drive force of the motor and the engine. A mode determination unit that determines a transition condition from the electric travel mode to the split travel mode, and a shift stage that determines a shift stage of the automatic transmission and outputs a shift request for shifting the automatic transmission A determination unit; an output member rotation speed calculation unit that calculates a post-shift output member rotation speed that is a rotation speed of the output member in a state in which the automatic transmission is shifted to a shift stage according to the shift request; and the split travel mode When the shift condition to the shift position is established, and the shift to the shift stage according to the shift request is not completed in the automatic transmission, the input member is rotated. Further comprising an engine control unit for speed controls the rotational speed of the engine so that the post-shift output member rotational speed, a.

  The engine control unit preferably controls the rotational speed of the engine so that the rotational speed of the input member becomes a rotational speed obtained by adding the adjusted rotational speed to the post-shift output member rotational speed.

  In addition, the engine control unit, when a rotational speed obtained by adding the adjusted rotational speed to the post-shift output member rotational speed or the post-shift output member rotational speed is lower than the idling rotational speed of the engine, It is preferable to control the rotational speed of the engine so that the rotational speed of the engine becomes equal to or higher than the idling rotational speed.

  According to the present invention, the mode determination unit determines a transition condition from the electric travel mode to the split travel mode, and the shift speed determination unit determines a shift speed of the automatic transmission and shifts the automatic transmission. The output member rotation speed calculation unit calculates a post-shift output member rotation speed that is a rotation speed of the output member in a state where the automatic transmission has been shifted to a shift speed according to the shift request. When the engine control unit determines that the condition for shifting to the split travel mode is satisfied and the shift to the shift stage due to the shift request is not completed, the rotation speed of the input member is changed to the output member after the shift. The engine rotation speed is controlled so as to be the rotation speed.

  As a result, the rotational speed of the engine is controlled so that the rotational speed of the input member becomes the rotational speed of the output member of the gear stage after the shift, and therefore the synchronization of the rotational speeds of the input member and the output member can be shortened. . For this reason, when the vehicle is running with only the motor and the engine is started and connected to the automatic transmission, the connection time of the front clutch can be shortened. Further, since the time for connecting the front clutch can be shortened, the fuel consumed by the engine for synchronizing the front clutch can be reduced, and the fuel efficiency of the hybrid vehicle can be improved.

  The engine control unit controls the rotational speed of the engine so that the rotational speed of the input member becomes a rotational speed obtained by adding the adjusted rotational speed to the post-shift output member rotational speed. Thereby, when the front clutch is connected, it is possible to prevent the vehicle from decelerating due to the rotational speed of the input member being lower than the rotational speed of the output member, and to prevent the driver from feeling uncomfortable. be able to.

  In addition, the engine control unit determines that the rotation speed of the input member is idling when the rotation speed of the output member after shifting or the rotation speed obtained by adding the adjusted rotation speed to the rotation speed of the output member after shifting is lower than the idling rotation speed of the engine. The engine speed is controlled so as to be equal to or higher than the speed. This prevents the engine speed from being controlled to be equal to or lower than the idling speed at the start of the vehicle or the like, thereby preventing engine stall.

It is explanatory drawing of the hybrid vehicle by which the drive device for hybrid vehicles by one Embodiment of this invention is mounted. It is a graph with the vehicle speed V on the horizontal axis and the accelerator opening degree Ac on the vertical axis, and is an explanatory diagram of the shift line of the automatic transmission. A graph showing the relationship between elapsed time, input shaft rotation speed, target engine rotation speed, engine rotation speed, required shift speed, actual shift speed, and engine status when an upshift is executed when the front clutch is engaged. is there. A graph showing the relationship between elapsed time, input shaft rotation speed, target engine rotation speed, engine rotation speed, required shift speed, actual shift speed, and engine status when downshift is executed when the front clutch is engaged. is there. When the stopped vehicle starts and connects the front clutch, the relationship between the elapsed time and the input shaft rotation speed, target engine rotation speed, engine rotation speed, required shift speed, actual shift speed, and engine state It is a represented graph. 2 is a flowchart of a “target engine speed setting process” executed by a control unit in FIG. 1.

(Description of hybrid vehicle)
A hybrid vehicle drive apparatus 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an outline of a hybrid vehicle (hereinafter abbreviated as a vehicle) on which a hybrid vehicle drive device 1 is mounted. In FIG. 1, thick lines indicate mechanical connections between the devices, broken arrows indicate control signal lines, and alternate long and short dashed arrows indicate vehicle power supply lines.

  As shown in FIG. 1, the hybrid vehicle drive device 1 includes an engine 2, a front clutch 5, a clutch actuator 53, an automatic transmission 8, a shift selector actuator 85, a motor generator 6, an inverter device 15, a battery 16, and a control unit. 10. The hybrid vehicle drive device 1 applies drive force to the drive wheels 18R and 18L.

  In the vehicle, an engine 2, a front clutch 5, an automatic transmission 8, a motor generator 6, and a differential 17 are arranged in series in this order. The differential 17 is connected to drive wheels 18R and 18L of the vehicle. The drive wheels 18R and 18L are front or rear wheels or front and rear wheels of the vehicle.

  The engine 2 is a gasoline engine or a diesel engine that uses hydrocarbon fuel such as gasoline or light oil. The engine 2 includes an output shaft 21, a throttle valve 22, a fuel injection device 23, and an engine rotation speed sensor 24, and is controlled by the control unit 10. The output shaft 21 rotates integrally with a crankshaft that is driven to rotate by a piston and outputs a driving force.

  The throttle valve 22 is arranged in the middle of a path for taking air into the engine 2. The fuel injection device 23 injects fuel into at least one of a path for taking air into the engine 2 and a combustion chamber. In the present embodiment, the output shaft 21 of the engine 2 is connected to an input member 51 of the front clutch 5 described later. When the engine 2 is a gasoline engine, the engine 2 is provided with an ignition device (not shown) that ignites the air-fuel mixture in the cylinder. The engine rotation speed sensor 24 is provided in the vicinity of the output shaft 21, detects the rotation speed of the output shaft 21, that is, the rotation speed of the engine 2 (hereinafter abbreviated as the engine rotation speed Ne), and uses the detection signal as a control unit. 10 is a sensor that outputs to 10.

  The front clutch 5 connects or disconnects the output shaft 21 of the engine 2 and the input shaft 81 of the automatic transmission 8. The front clutch 5 is provided between the engine 2 and the motor generator 6. In the present embodiment, the front clutch 5 is provided between the engine 2 and the automatic transmission 8.

  The front clutch 5 is a wet multi-plate friction clutch, a dry single-plate friction clutch, or the like. The front clutch 5 includes an input member 51 connected to the output shaft 21 and an output member 52 connected to the input shaft 81. Since the input member 51 is connected to the output shaft 21, the rotational speed of the input member 51 is the same as the rotational speed of the output shaft 21, that is, the engine rotational speed Ne. Since the output member 52 is connected to the input shaft 81, the rotational speed of the output member 52 is the same as the input shaft rotational speed Ni.

  The input member 51 and the output member 52 are switched between a connected state and a disconnected state by the clutch actuator 53. In the present embodiment, the front clutch 5 is a normally closed clutch that is connected when the clutch actuator 53 is not operating.

  The automatic transmission 8 is provided between the front clutch 5 and the drive wheels 18R and 18L. In the present embodiment, the automatic transmission 8 is provided between the front clutch 5 and the motor generator 6. The automatic transmission 8 has an input shaft 81 that rotates in conjunction with the output member 52 and an output shaft 82 that rotates in conjunction with the drive wheels 18R and 18L. The automatic transmission 8 includes a speed change mechanism that selectively switches a plurality of gear stages (including reverse) having different speed ratios obtained by dividing the rotational speed of the input shaft 81 by the rotational speed of the output shaft 82. Machine.

  A driving force from the engine 2 is input to the input shaft 81. The automatic transmission 8 includes a shift selector actuator 85 that operates a transmission mechanism based on a command from the control unit 10 and selectively switches a plurality of gear stages to implement a shift. In the present embodiment, the automatic transmission 8 is an automated manual transmission (AMT) having a synchronization mechanism.

  The automatic transmission 8 includes an input shaft rotation speed sensor 83 that detects the rotation speed of the input shaft 81 and outputs a detection signal to the control unit 10.

  The motor generator 6 applies driving force to the drive wheels 18L and 18R and generates power during deceleration. The motor generator 6 is provided between the engine 2 and the drive wheels 18L and 18R. In the present embodiment, the motor generator 6 is provided between the automatic transmission 8 and the differential 17.

  The motor generator 6 includes a cylindrical stator and a rotor that is rotatably disposed on the inner peripheral side of the stator. The stator is configured by winding a winding around a stator core. The rotor is configured by attaching a permanent magnet to a rotor core. In the present embodiment, the motor generator 6 is a three-phase synchronous machine. The rotor is connected to the output shaft 82 and to the differential 17.

  In the vicinity of the wheels 18R and 18L, wheel rotation speed sensors 88 and 89 for detecting the rotation speed of the wheels 18R and 18L (hereinafter abbreviated as wheel rotation speeds Nwr and Nwl) are provided. The wheel rotation speeds Nwr and Nwl detected by the wheel rotation speed sensors 88 and 89 are output to the control unit 10.

  The inverter device 15 converts the direct current supplied from the battery 16 into an alternating current, changes the frequency and effective value of the voltage of the alternating current, and supplies it to the motor generator 6. Further, the inverter device 15 converts the alternating current generated by the motor generator 6 into a direct current and charges the battery 16.

  The control unit 10 controls the hybrid vehicle drive device 1. The control unit 10 is connected to the throttle valve 22, the fuel injection device 23, the engine rotation speed sensor 24, the clutch actuator 53, the input shaft rotation speed sensor 83, and the shift selector actuator 85. The control unit 10 includes an ECU that includes a CPU, a RAM, a storage unit, and a bus connecting them. The CPU executes a program corresponding to the flowchart shown in FIG. The RAM temporarily stores variables necessary for executing the program. The storage unit is configured by a nonvolatile memory or the like and stores the program.

  The control unit 10 acquires information about the accelerator opening degree Ac that means the relative value of the operation amount from the accelerator sensor 32 that detects the operation amount of the accelerator pedal 31. The control unit 10 calculates “required driving force” based on the accelerator opening degree Ac. The control unit 10 calculates the “motor driving force” based on information such as the state of charge of the battery 16 and the vehicle speed V. The control unit 10 calculates the “engine driving force” based on the “required driving force” and the “motor driving force”. The control unit 10 (engine control unit) controls the opening degree of the throttle valve 22 and the fuel injection amount of the fuel injection device 23 based on “engine driving force”, and the driving force output by the engine 2 is “engine driving force”. To control. A “required driving force” is applied to the vehicle by at least one of these “engine driving force” and “motor driving force”.

  The control unit 10 controls the operation of the inverter device 15 to perform switching control between the driving mode and the power generation mode of the motor generator 6 and controls the motor generator rotational speed Nm and the “motor driving force” of the motor generator 6. Do.

  The control unit 10 (mode determination unit) determines whether to switch between the “electric travel mode” and the “split travel mode” based on the charging state of the battery 16 and the accelerator opening degree Ac. The “electric travel mode” is a travel mode in which the drive wheels 18R and 18L are driven only by the motor generator 6. In the “split running mode”, the driving wheels 18R and 18L are driven by the engine 2 and the motor generator 6, or the driving wheels 18R and 18L are driven by the driving force of the engine 2, and the motor generator is driven by the driving force of the engine 2. 6 is a mode for generating power.

  When determining that the charge amount of the battery 16 is small, the control unit 10 selects the “split travel mode” and drives the driving wheels 18R and 18L by the driving force of the engine 2 and the driving force of the engine 2 Thus, the motor generator 6 generates power. When it is determined that the accelerator opening Ac is large and the “required driving force” is not reached only by the “motor driving force”, the “split running mode” is selected and the engine 2 and the motor generator 6 drive the driving wheels. 18R and 18L are driven.

  The control unit 10 operates the clutch actuator 53 to place the front clutch 5 in a connected state or a disconnected state, and connect or disconnect the output shaft 21 and the input shaft 81. As described above, the control unit 10 switches to the “electric travel mode” by disconnecting the front clutch 5 and switches to the “split travel mode” by connecting the front clutch 5.

(Explanation of shift map data)
Next, the “shift map data” will be described with reference to FIG. The “shift map data” is data that serves as a reference for execution of shift in the automatic transmission 8 by the control unit 10. As shown in FIG. 2, the “shift map data” has a plurality of “shift lines” representing the relationship between the accelerator opening degree Ac and the vehicle speed V. A second speed up shift line and a third speed up shift line (shown by a solid line in FIG. 2) are set in order in the speed increasing direction (from the lower vehicle speed V toward the higher speed). Further, a second speed down shift line and a first speed down shift line (shown by broken lines in FIG. 2) are set in order in the deceleration direction (from the higher vehicle speed V to the lower vehicle speed V). Similarly, a “shift line” is set for more gear stages.

  In FIG. 2, when the vehicle is traveling at the first gear position of the automatic transmission 8 (P0 state), the vehicle speed V gradually increases and the vehicle traveling state is on the second speed up shift line. When the point P1 is reached, the control unit 10 (shift determination unit) outputs a “shift request” to the second speed. On the other hand, when the vehicle is traveling at the second speed of the automatic transmission 8 (the state of P2), the vehicle speed V gradually decreases, and the traveling state of the vehicle is on the first speed down shift line. When the point P3 is reached, the control unit 10 outputs a “shift request” to the first speed. The control unit 10 outputs a control signal to the shift selector actuator 85 so as to achieve the above-described “shift request” shift stage. The shift selector actuator 85 shifts the automatic transmission 8 to the gear position of “shift request”. It should be noted that the shift speed may be determined based on the rotational speed of the output shaft 82 instead of the vehicle speed V.

  The control unit 10 calculates the vehicle speed V based on the wheel rotation speeds Nwr and Nwl detected by the wheel rotation speed sensors 88 and 89, respectively.

(Target engine speed setting process)
The “target engine speed setting process” will be described below with reference to the flowchart of FIG. When the ignition is turned on and the vehicle is ready to travel, the process proceeds to S11.

  In S11, when the control unit 10 determines that the condition for transition to the “split travel mode” is satisfied (S11: YES), the program proceeds to S12, and the condition for transition to the “split travel mode” is satisfied. If it is determined that it is not (S11: NO), the process of S11 is repeated. As described above, when the vehicle is running with the driving force of only the motor generator 6, the “required driving force” detected by the accelerator sensor 32 exceeds the “motor driving force” or the remaining amount of the battery 16. Is decreased, it is determined that the condition for shifting to the “split travel mode” is satisfied.

  In S12, the control unit 10 determines that the current gear position of the automatic transmission 8 (hereinafter abbreviated as “actual gear position”) is different from the gear position of “shift request” (hereinafter referred to as “requested gear position”). If so (S12: YES), the program proceeds to S13. If it is determined that the “actual shift speed” and the “required shift speed” are the same (S12: NO), the program proceeds to S15.

In S13, the control unit 10 substitutes the wheel rotation speed VW output from the wheel rotation speed sensors 88 and 89 into the following expression (1), thereby rotating the input shaft at the shift stage (after the shift) of “shift request”. The speed Ni is calculated.
Ni = Nw × A
Ni = input shaft rotation speed (r.p.m.)
Nw = wheel rotation speed (r.p.m.)
A = Gear ratio after shifting Note that the wheel rotation speed VW is an average value of the wheel rotation speeds Nwr and Nwl detected by the wheel rotation speed sensors 88 and 89, respectively. The gear ratio A after the shift is a value obtained by dividing the input shaft rotation speed Ni after the shift by the wheel rotation speed Nw, and is a characteristic set by the gear ratio of the differential 17 and the gear ratio of the automatic transmission 8. Is the value of Then, the control unit 10 calculates a rotational speed obtained by adding the adjusted rotational speed α (50 to 100 rpm) to the calculated input shaft rotational speed Ni, and sets it as “target rotational speed”. . The adjusted rotational speed α is a rotational speed that is set so that the driver does not feel a sense of deceleration when the front clutch 5 is connected. When S13 ends, the program proceeds to S17.

  In S <b> 15, the control unit 10 sets a rotation speed obtained by adding the adjustment rotation speed α to the input shaft rotation speed Ni detected by the input shaft rotation speed sensor 83 as a “target rotation speed”. When S15 ends, the program proceeds to S17.

  In S <b> 17, the control unit 10 sets the fast engine speed between the “target engine speed” set in S <b> 13 or S <b> 15 and the “idling engine speed” (for example, 800 to 1200 rpm) of the engine 2 as the target engine speed. Set as speed Nae. When S17 ends, the program returns to S11.

  When the target engine rotational speed Nae is set, the control unit 10 controls the opening degree of the throttle valve 22 and the fuel injection amount of the fuel injection device 23 so that the rotational speed of the engine 2 (output shaft 21) becomes the target engine rotational speed. Engine control is executed so that the speed becomes Nae. When the controller 10 determines that the engine rotational speed Ne has reached the target engine rotational speed Nae, the controller 10 outputs a control signal to the clutch actuator 53 to connect the front clutch 5. Thereby, the driving force of the engine 2 is transmitted to the driving wheels 18R and 18L.

(Description of specific hybrid vehicle drive device operation)
[Upshift is performed when the front clutch is engaged]
Hereinafter, the operation of the hybrid vehicle drive device 1 when the upshift is executed when the front clutch 5 is engaged will be described with reference to FIGS. 3 and 6. In the example shown in FIG. 3, the front clutch 5 is in a disconnected state, and the vehicle is running with the driving force of only the motor generator 6. For this reason, the input shaft rotational speed Ni is not 0 ((1) in FIG. 3).

  At t0, a “shift request” for upshifting is output ((2) in FIG. 3). When it is determined in S11 of FIG. 6 that the condition for shifting to the “split travel mode” is established, the control unit 10 controls the opening of the throttle valve 22 and the fuel injection amount of the fuel injection device 23 to control the engine 2 The start control is started ((3) in FIG. 3). In this state, since the “actual shift speed” and the “required shift speed” are different, it is determined YES in S12, and in S13 and S17, the rotation obtained by adding the adjusted rotation speed α to the input shaft rotation speed Ni after the shift. The speed is set as the target engine speed Nae ((4) in FIG. 3).

  And the engine 2 is controlled so that it may become target engine speed Nae ((5) of FIG. 3). For this reason, the engine rotational speed Ne is unnecessarily increased as compared with the case where the engine 2 is controlled so that the input shaft rotational speed Ni of the “actual gear stage” is reached as in the prior art ((6) in FIG. 3). Can be prevented.

  In addition, conventionally, when the upshift is executed, the input shaft rotational speed Ni decreases ((7) in FIG. 3), and therefore the engine rotational speed Ne and the input shaft rotational speed Ni deviate ( (8) in FIG. 3) As a result, it is necessary to wait for a decrease in the engine rotational speed Ne whose rotation has increased unnecessarily ((9) in FIG. 3), and in synchronization with the input shaft rotational speed Ni and the engine rotational speed Ne It takes a long time ((10) in FIG. 3), and the connection of the front clutch 5 is prolonged. For this reason, since the state in which the driving force of the engine 2 is not transmitted to the drive wheels 18R and 18L is prolonged, the driver's intention to accelerate and the actual acceleration of the vehicle deviate, and the drivability of the vehicle deteriorates.

  On the other hand, in the present embodiment, the engine rotational speed Ne is controlled to the target engine rotational speed Nae obtained by adding the adjusted rotational speed α to the input shaft rotational speed Ni of the gear stage after the shift, so that the input shaft rotational speed Ni and the engine The rotation speed Ne can be synchronized in a short time, and the front clutch 5 can be connected in a short time.

[When downshift is executed when the front clutch is engaged]
Hereinafter, the operation of the hybrid vehicle drive device 1 when the downshift is executed when the front clutch 5 is connected will be described with reference to FIGS. 4 and 6. In the example shown in FIG. 4, the front clutch 5 is in a disconnected state, and the vehicle is running with the driving force of only the motor generator 6. For this reason, the input shaft rotational speed Ni is not 0 ((1) in FIG. 4).

  At t0, a “shift request” for upshifting is output ((2) in FIG. 4). When it is determined in S11 of FIG. 6 that the condition for shifting to the “split travel mode” is established, the control unit 10 controls the opening of the throttle valve 22 and the fuel injection amount of the fuel injection device 23 to control the engine 2 The start control is started ((3) in FIG. 4). In this state, since the “actual shift speed” and the “required shift speed” are different, it is determined YES in S12, and in S13 and S17, the rotation speed obtained by adding the adjusted rotation speed α to the input shaft rotation speed Ni after the shift. Is set as the target engine speed Nae ((4) in FIG. 4).

  And the engine 2 is controlled so that it may become target engine speed Nae ((5) of FIG. 4). For this reason, the engine rotation speed Ne can be quickly increased.

  In other words, conventionally, the engine 2 is controlled so as to achieve the “actual shift speed” input shaft rotational speed Ni ((6) in FIG. 3), so the downshift is executed and the input shaft rotational speed Ni increases. Then ((7) in FIG. 4), the engine rotational speed Ne and the input shaft rotational speed Ni deviate, and the engine 2 is controlled so as to become the input shaft rotational speed Ni after completion of the downshift again (((4) in FIG. 4). 8)). For this reason, it takes a long time to synchronize the input shaft rotational speed Ni and the engine rotational speed Ne ((9) in FIG. 4), and the connection of the front clutch 5 is prolonged. For this reason, since the state in which the driving force of the engine 2 is not transmitted to the drive wheels 18R and 18L is prolonged, the driver's intention to accelerate and the actual acceleration of the vehicle deviate, and the drivability of the vehicle deteriorates.

[When a stopped vehicle starts with the driving force of the motor generator and connects the front clutch]
In the following, referring to FIG. 5 and FIG. 6, the stopped vehicle starts with the driving force of the motor generator 6, starts the engine 2, connects the front clutch 5, and drives the driving force of the engine 2. The vehicle control when the wheels 18r and 18L are added will be described. In the example shown in FIG. 5, at t0, the front clutch 5 is in a disconnected state, and the vehicle is stopped. For this reason, the input shaft rotational speed Ni is 0 ((1) in FIG. 5).

  When the accelerator pedal 31 is greatly depressed at t1 and it is determined in 11 of FIG. 6 that the condition for shifting to the “split travel mode” is satisfied (S11: YES), the control unit 10 controls the drive of the motor generator 6. At the same time ((2) in FIG. 5), the control for starting the engine 2 is started by controlling the opening of the throttle valve 22 and the fuel injection amount of the fuel injection device 23 ((3) in FIG. 5).

  In this state, since the “actual shift speed” and the “required shift speed” are the same, it is determined NO in S12, and in S15, the rotation speed obtained by adding the adjustment rotation speed α to the current input shaft rotation speed Ni is obtained. , “Target rotational speed” is calculated. However, when the control unit 10 determines in S17 that the “target rotational speed” is lower than the “idling rotational speed” of the engine 2, the “idling rotational speed” of the engine 2 is set as the target engine rotational speed Nae. ((4) in FIG. 5). In S17, when the control unit 10 determines that the “target rotational speed” is higher than the “idling rotational speed” of the engine 2, the “target rotational speed” is set as the target engine rotational speed Nae (FIG. (5)). Thereafter, when the engine rotational speed Ne becomes equal to the target engine rotational speed Nae ((6) in FIG. 5), the front clutch 5 is connected ((7) in FIG. 5), and the driving force of the engine 2 is changed to the driving wheels 18R. , 18L.

  As described above, when it is determined that the “target rotational speed” is lower than the “idling rotational speed” of the engine 2, the “idling rotational speed” of the engine 2 is set as the target engine rotational speed Nae. 2 is prevented from being controlled to a rotational speed lower than the “idling rotational speed”, and engine stall can be prevented.

(Effect of this embodiment)
As described above, in S <b> 11 of FIG. 6, the control unit 10 (mode determination unit) determines the transition condition from the “electric travel mode” to the “split travel mode”. Then, the control unit 10 (shift speed determination unit) determines the shift speed of the automatic transmission 8 based on the vehicle speed V, the accelerator opening degree Ac, and the “shift map data” shown in FIG. A “shift request” for shifting is output to the shift selector actuator 85. In S13 of FIG. 6, the control unit 10 (output member rotation speed calculation unit) determines the input shaft rotation speed Ni (the output member rotation after the shift) after the automatic transmission 8 has been shifted to the shift stage according to the “shift request”. Speed). Then, the control unit 10 (engine control unit) establishes the condition for shifting to the “split travel mode” (YES in S11 of FIG. 6) and completes the shift to the gear position based on the “shift request”. If it is determined that it is not (YES in S12), the rotational speed of the input member 51 becomes the rotational speed of the output member 52, that is, the engine rotational speed Ne becomes the input shaft rotational speed Ni. The rotational speed of the engine 2 is controlled.

  As a result, the engine rotation speed Ne is controlled so that the rotation speed of the input member 51 becomes the rotation speed of the output member 52 of the gear stage after the shift. It can be shortened. For this reason, in the case where the engine 2 is started and connected to the automatic transmission 8 while the vehicle is traveling only by the motor generator 6, the connection time of the front clutch 5 can be shortened. Further, since the connection time of the front clutch 5 can be shortened, the fuel consumed by the engine 2 for the synchronization of the front clutch 5s can be reduced, and the fuel consumption of the vehicle can be improved.

  Further, unlike the invention described in Patent Document 1, a start map corresponding to the ratio between the engine rotational speed Ne and the input shaft rotational speed Ni when the start condition of the engine 2 is satisfied is not required. Work becomes unnecessary.

  Further, the control unit 10 (engine control unit) controls the rotation speed of the engine 2 so that the rotation speed of the input member 51 becomes a rotation speed obtained by adding the adjustment rotation speed α to the rotation speed of the output member 52. In other words, in S13 of FIG. 6, the control unit 10 sets the rotational speed obtained by adding the adjusted rotational speed α to the input shaft rotational speed Ni after the shift as the target engine rotational speed Nae so as to be the target engine rotational speed Nae. The engine 2 is controlled. Therefore, in this embodiment, when the front clutch 5 is connected, it is possible to prevent the vehicle from decelerating due to the rotational speed of the input member 51 being lower than the rotational speed of the output member 52.

  That is, even if the control unit 10 controls the rotation of the engine 2, the engine rotation speed Ne is not necessarily the same as the target engine rotation speed Nae. For this reason, by setting the rotational speed obtained by adding the adjusted rotational speed α to the input shaft rotational speed Ni after the shift as the target engine rotational speed Nae, the actual engine rotational speed Ne is lower than the target engine rotational speed Nae. Even if controlled, the rotation speed of the input member 51 is prevented from becoming lower than the rotation speed of the output member 52, and the vehicle is prevented from decelerating. Thereby, it is possible to prevent the driver from feeling uncomfortable.

  In S17 of FIG. 6, when the control unit 10 (engine control unit) determines that the “target rotation speed” set in S13 and S15 is lower than the “idling rotation speed” of the engine 2, The “idling rotational speed” is set as the target engine rotational speed Nae. As a result, the rotational speed of the engine 2 is controlled so as to be “over idling rotational speed”. Therefore, in the situation as shown in FIG. 5, that is, when the vehicle starts, the rotation speed of the engine 2 is prevented from being controlled below the “idling rotation speed”, and engine stall can be prevented. .

(Another embodiment)
In the embodiment described above, the motor generator 6 is provided between the automatic transmission 8 and the differential 17. However, it goes without saying that the technical idea of the present invention can also be applied to an embodiment in which the motor generator 6 is provided between the front clutch 5 and the automatic transmission 8.

  In the embodiment described above, the vehicle speed V and the rotational speed of the output shaft 82 are detected by the wheel rotational speed sensors 88 and 89. However, there may be an embodiment in which the vehicle speed V and the rotational speed of the output shaft 82 are detected by an output shaft rotational speed sensor that is disposed in the vicinity of the output shaft 82 and directly detects the rotational speed of the output shaft 82.

  In the embodiment described above, the rotation speed obtained by adding the adjusted rotation speed α to the input shaft rotation speed Ni after the shift is set as the “target rotation speed” in S13 of FIG. 6, and the current input shaft rotation speed is set in S15. A rotation speed obtained by adding the adjustment rotation speed α to Ni is set as a “target rotation speed”. However, the input shaft rotation speed Ni after the shift and the current input shaft rotation speed Ni may be the “target rotation speed”.

  In the embodiment described above, the output shaft 21 and the input member 51 are connected, and the input shaft 81 and the output member 52 are connected. However, there may be an embodiment in which a mechanical element such as a gear is provided between the output shaft 21 and the input member 51 or between the input shaft 81 and the output member 52.

  In the embodiment described above, the automatic transmission 8 is an AMT having a synchronization mechanism. However, the automatic transmission 8 is also used in a hybrid vehicle drive device such as an AMT having a dog clutch, a dual clutch transmission (DCT), a torque converter, a planetary gear mechanism, a torque converter type automatic transmission using a friction engagement element, and the like. Needless to say, the technical idea of the present invention is applicable.

  In the above description, the present invention has been described with respect to the embodiment using the motor generator 6 that operates as a motor that applies driving force to the drive wheels 18L and 18R and also operates as a generator. However, the motor and the generator may be separate embodiments.

  The control unit 10 is not limited to a single ECU, and may be an embodiment including a plurality of ECUs.

DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle drive device, 2 ... Engine, 5 ... Front clutch, 8 ... Automatic transmission, 6 ... Motor generator (motor), 10 ... Control part (Mode judgment part, Shift judgment part, Output member rotational speed calculation part , Engine control unit), 18R, 18L ... drive wheels, 51 ... input member, 52 ... output member, 81 ... input shaft, 82 ... output shaft Nae ... target engine rotational speed Ne ... engine rotational speed Ni ... input shaft rotational speed

Claims (3)

An engine that applies driving force to the drive wheels;
A motor that is provided between the engine and the driving wheel and applies a driving force to the driving wheel;
A front side provided between the engine and the motor and having an input member that is rotationally connected to the engine and an output member that is rotationally connected to the motor, and connects or disconnects the input member and the output member Clutch,
An input shaft that is provided between the front clutch and the drive wheel and rotates in conjunction with the output member; and an output shaft that rotates in conjunction with the drive wheel; An automatic transmission that selectively shifts a plurality of shift stages having different gear ratios divided by the rotation speed of the output shaft to perform a shift,
The front clutch connects the input member and the output member to drive the motor and the engine by connecting the input member and the output member to an electric travel mode in which the input member and the output member are disconnected and traveled only by the driving force of the motor. It is possible to switch the split running mode that runs with power,
A mode determination unit for determining a transition condition from the electric driving mode to the split driving mode;
A shift speed determination unit for determining a shift speed of the automatic transmission and outputting a shift request for shifting the automatic transmission;
An output member rotation speed calculation unit that calculates a post-shift output member rotation speed that is a rotation speed of the output member in a state of being shifted to a shift stage according to the shift request;
The rotation speed of the input member is set to the shift speed when the mode determination unit satisfies the condition for shifting to the split travel mode and the automatic transmission does not complete the shift to the shift stage according to the shift request. A hybrid vehicle drive device further comprising: an engine control unit that controls a rotational speed of the engine so as to be a rear output member rotational speed.   2. The hybrid vehicle according to claim 1, wherein the engine control unit controls the rotation speed of the engine so that a rotation speed of the input member becomes a rotation speed obtained by adding an adjustment rotation speed to the output member rotation speed after shifting. Drive device.   The engine control unit rotates the input member when the post-shift output member rotational speed or a rotational speed obtained by adding the adjusted rotational speed to the post-shift output member rotational speed is lower than the idling rotational speed of the engine. The hybrid drive device according to claim 1, wherein the rotational speed of the engine is controlled so that the speed is equal to or higher than the idling rotational speed.

Images