JP6295627B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention controls a hybrid vehicle including an engine and a travel motor in a drive system, a clutch interposed between the engine and the travel motor, and a transmission interposed between the travel motor and a drive wheel. Relates to the device.

  In a hybrid vehicle, it is known that the torque after fastening of an engine and a motor generator (travel motor) always depends on the engine torque. (For example, refer to Patent Document 1).

JP 2010-188905 A

  However, in the conventional hybrid vehicle, even if the engine torque can be assisted by the motor torque after the fastening, such as the battery SOC is relatively high, the torque after the fastening is not assisted by the motor torque. Always rely on engine torque. For this reason, there existed a problem that engine load may become high and a fuel consumption may deteriorate.

  The present invention has been made paying attention to the above-mentioned problem. When it is determined that there is an assist margin for an engine start request during EV traveling, a hybrid vehicle capable of suppressing deterioration in fuel consumption after engine start is provided. An object is to provide a control device.

In order to achieve the above object, a control apparatus for a hybrid vehicle according to the present invention includes an engine and a travel motor in a drive system, and a clutch is interposed between the engine and the travel motor, A transmission is interposed between the drive wheels.
When the hybrid vehicle control device has an engine start request in an EV mode using the travel motor as a drive source, an engine start control means for starting the engine, the engine sandwiching the clutch, and the travel Based on the differential rotation calculation means for calculating the differential rotation with the motor, the high-power battery that is a power source of the travel motor, and the state of the high-power battery, the travel motor assists the engine after the engine is started. And a post-start assist margin judging means for judging whether or not there is a torque assist margin.
The engine start control means performs an upshift when it is determined that there is an assist margin when it is determined that the differential rotation is greater than a predetermined differential rotation when an engine start request is made during traveling in the EV mode. Then, start the engine.

Therefore, when there is an engine start request during traveling in the EV mode (hereinafter referred to as “EV traveling”) by the engine start control means, if it is determined that there is an assist margin, an upshift is performed and the engine Start is performed.
That is, when it is determined that there is an assist margin at the time of engine start request during EV traveling, an upshift that reduces the input rotational speed (= motor rotational speed) of the transmission is executed. For this reason, the engine and the traveling motor are fastened by the clutch on the lower rotation side than the case where the speed is not changed, so that the engine torque is kept low. Further, after the clutch is engaged, the engine torque can be assisted by the motor torque for the assist margin. That is, the engine load after the engine is started is reduced, and deterioration of fuel consumption is suppressed.
As a result, when it is determined that there is an assist margin for an engine start request during EV traveling, it is possible to suppress deterioration in fuel consumption after engine start.

1 is an overall system diagram illustrating an FF plug-in hybrid vehicle to which a control device according to a first embodiment is applied. It is a flowchart which shows the process in the engine starting control of FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the process in the acceleration intention determination of FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the assist margin determination process after starting of the FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied. It is engine start control of FF plug-in hybrid vehicle to which the control apparatus of Example 1 is applied, Comprising: It is an engine start area | region map when there exists an engine start request | requirement. In the engine start control of the FF plug-in hybrid vehicle to which the control device of the first embodiment is applied, the motor speed and the engine speed of the motor / generator 4 sandwiching the first clutch 3 from the time of the engine start request are calculated. It is a map to show. It is engine start control of FF plug-in hybrid vehicle to which the control apparatus of Example 1 is applied, Comprising: It is a time chart which shows the 1st engine start control processing operation example during EV driving | running | working. It is engine start control of FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied, Comprising: It is a time chart which shows the 2nd engine start control processing operation example during EV driving | running | working. It is engine start control of FF plug-in hybrid vehicle to which the control apparatus of Example 1 is applied, Comprising: It is a time chart which shows the 3rd engine start control processing operation example in EV driving | running | working.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on a first embodiment shown in the drawings.

  First, the configuration will be described. The configuration of the FF plug-in hybrid vehicle (an example of a hybrid vehicle) to which the control device according to the first embodiment is applied will be described separately as “drive system configuration”, “power supply system configuration”, and “control system configuration”.

[Drive system configuration]
FIG. 1 shows the entire FF plug-in hybrid vehicle. Hereinafter, the drive system configuration of the FF plug-in hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the drive system includes a starter motor 1 (abbreviated as “M”), a horizontal engine 2 (engine, abbreviated as “ICE”), and a first clutch 3 (clutch, abbreviated as “CL1”). , Motor / generator 4 (travel motor, abbreviated “M / G”), second clutch 5 (abbreviated “CL2”), and belt-type continuously variable transmission 6 (transmission, abbreviated “CVT”) I have. The output shaft of the belt type continuously variable transmission 6 is drivably coupled to the left and right front wheels 10R and 10L (drive wheels) via a final reduction gear train 7, a differential gear 8, and left and right drive shafts 9R and 9L. The left and right rear wheels 11R and 11L are driven wheels.

  The starter motor 1 is a cranking motor that has a gear that meshes with an engine starting gear provided on a crankshaft of the horizontally placed engine 2 and that uses a capacitor 23 (described later) as a power source to rotationally drive the crankshaft when the engine is started.

  The horizontal engine 2 is an engine disposed in the front room with the crankshaft direction as the vehicle width direction, and includes an electric water pump 12 and a crankshaft rotation sensor 13 that detects reverse rotation of the horizontal engine 2.

  The first clutch 3 is a normally open dry multi-plate friction clutch that is hydraulically interposed between the horizontally mounted engine 2 and the motor / generator 4 and is fully engaged / slip-engaged (slipped) by the first clutch oil pressure. Status) / Open is controlled.

  The motor / generator 4 is a three-phase AC permanent magnet type synchronous motor connected to the transverse engine 2 through a first clutch 3. The motor / generator 4 uses a high-power battery 21 described later as a power source, and an inverter 26 that converts direct current into three-phase alternating current during power running and converts three-phase alternating current into direct current during regeneration is connected to the stator coil. Connected through.

  The second clutch 5 is a wet-type multi-plate friction clutch by hydraulic operation that is interposed between the motor / generator 4 and the left and right front wheels 10R and 10L that are driving wheels. Slip fastening (slip state) / release is controlled. The second clutch 5 of the first embodiment uses the forward clutch 5a and the reverse brake 5b provided in the forward / reverse switching mechanism of the belt-type continuously variable transmission 6 using planetary gears. That is, the forward clutch 5 a is the second clutch 5 during forward travel, and the reverse brake 5 b is the second clutch 5 during reverse travel.

  The belt type continuously variable transmission 6 is bridged between a primary pulley PrP connected to the transmission input shaft input, a secondary pulley SeP connected to the transmission output shaft output, and the primary pulley PrP and the secondary pulley SeP. A continuously variable transmission having a pulley belt BE.

  The primary pulley PrP has a fixed sheave fixed to the transmission input shaft input and a movable sheave slidably supported on the transmission input shaft input. The secondary pulley SeP has a fixed sheave fixed to the transmission output shaft output and a movable sheave supported slidably on the transmission output shaft output.

  The pulley belt BE is a metal belt wound around the primary pulley PrP and the secondary pulley SeP, and is sandwiched between the fixed sheave and the movable sheave. Here, a large number of elements with inclined surfaces in contact with both the fixed sheave and the movable sheave are stacked on both sides, and two sets of rings formed in a ring shape and sandwiched between layers are sandwiched between both sides of the element. A so-called VDT belt is used.

  This belt-type continuously variable transmission 6 is a transmission that obtains a continuously variable transmission ratio by changing the belt winding diameter by the transmission hydraulic pressure to the primary oil chamber and the secondary oil chamber. That is, the pulley width of both pulleys PrP and SeP is changed by sliding the movable sheaves of the primary sheave PrP and the sheave of the secondary pulley SeP by the shift hydraulic pressure, and the diameter of the clamping surface of the pulley belt BE is changed. Change the gear ratio (pulley ratio) freely.

  The belt type continuously variable transmission 6 has a main oil pump 14 (mechanical drive, an oil pump serving as a hydraulic source for the first clutch 3), a sub oil pump 15 (motor drive), and a pump discharge pressure. And a control valve unit (not shown) that generates the first and second clutch hydraulic pressures and the shift hydraulic pressure using the generated line pressure as a source pressure. The main oil pump 14 is rotationally driven by a motor shaft (= transmission input shaft) of the motor / generator 4. The sub oil pump 15 is mainly used as an auxiliary pump for producing lubricating cooling oil.

  Here, as the pulley width of the primary pulley PrP increases and the pulley width of the secondary pulley SeP decreases, the gear ratio changes to the low side. Further, as the pulley width of the primary pulley PrP becomes narrower and the pulley width of the secondary pulley SeP becomes wider, the gear ratio changes to the high side.

The first clutch 3, the motor / generator 4, and the second clutch 5 constitute a one-motor / two-clutch drive system. The main drive modes of this drive system are “EV mode”, “HEV mode”, and “WSC”. Mode ".
The “EV mode” is an electric vehicle mode in which the first clutch 3 is disengaged and the second clutch 5 is engaged and only the motor / generator 4 is used as a drive source. That's it.
The “HEV mode” is a hybrid vehicle mode in which both the clutches 3 and 5 are engaged and the horizontal engine 2 and the motor / generator 4 are used as driving sources, and traveling in the “HEV mode” is referred to as “HEV traveling”. The “HEV mode” has a motor assist mode (motor power running), an engine power generation mode (generator regeneration), and a deceleration regeneration power generation mode (generator regeneration).
The “WSC mode” is a CL2 slip engagement mode in which the motor / generator 4 is controlled to rotate the motor and the second clutch 5 is slip-engaged with a transmission torque capacity corresponding to the required driving force. This "WSC mode" does not have a rotation differential absorption joint like a torque converter in the drive system, so in the starting area after stopping in the "HEV mode", etc. It is selected to absorb the rotational difference between the left and right front wheels 10L, 10R by CL2 slip engagement.

  The motor / generator 4 basically includes a regenerative cooperative brake unit 16 that controls the total braking torque when the brake is operated in accordance with the regenerative operation when the brake is operated. The regenerative cooperative brake unit 16 includes a brake pedal, an electric booster, and a master cylinder, and the electric booster shares the hydraulic braking force by subtracting the regenerative braking force from the required braking force that appears in the pedal operation amount when the brake is operated. In this way, cooperative control for regenerative / hydraulic pressure is performed.

[Power system configuration]
FIG. 1 shows an overall system of an FF plug-in hybrid vehicle. Hereinafter, the power supply system configuration of the FF plug-in hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the power supply system includes a high-power battery 21 as a motor / generator power supply, a 12V battery 22 as a 12V system load power supply, and a capacitor 23 as a starter power supply.

  The high-power battery 21 is a secondary battery mounted as a power source for the motor / generator 4. For example, a lithium ion battery (abbreviated as “LB”) in which a cell module in which a large number of cells are stacked is set in a battery pack case. Is used. The high-power battery 21 has a built-in junction box in which relay circuits for supplying / cutting off / distributing high-power are integrated, and further includes a battery temperature adjustment unit 24 having an air conditioner function, a battery charge capacity (battery SOC) and a battery. And a lithium battery controller 86 for monitoring the temperature.

  The high-power battery 21 and the motor / generator 4 are connected via a DC harness 25, an inverter 26, and an AC harness 27. The inverter 26 has a built-in junction box 28 in which relay circuits for supplying / cutting off / distributing strong power are integrated, and further includes a heating circuit 29, an electric air conditioner 30, and a motor controller 83 for performing power running / regenerative control. It is attached. That is, the inverter 26 converts a direct current from the DC harness 25 into a three-phase alternating current to the AC harness 27 during power running for driving the motor / generator 4 by discharging the high-power battery 21. Further, the three-phase alternating current from the AC harness 27 is converted into a direct current to the DC harness 25 during regeneration in which the high-power battery 21 is charged by power generation by the motor / generator 4. The motor controller 83 monitors the motor / generator temperature (motor temperature, M / G temperature), the motor applied current value, and the like. Here, the motor applied current value is a current value applied by converting electric power discharged from the high-power battery 21 into three-phase AC power by the inverter 26 during power running.

  A rapid external charging port 32 is connected to the high-power battery 21 via a DC harness 31, and a normal external charging port 35 is connected via a DC branch harness 25 ′, a charger 33, and an AC harness 34. . The charger 33 performs AC / DC conversion and voltage conversion. At the time of rapid external charging, for example, the external charging is performed by connecting the connector plug of the charging stand installed in the place of going out to the rapid external charging port 32 (rapid external charging). During normal external charging, external charging is performed by connecting a connector plug from a household power supply to the normal external charging port 35 (normal external charging), for example.

  The 12V battery 22 is a secondary battery mounted as a power supply for a 12V system load (not shown), which is another auxiliary device except the starter motor 1, and is generally mounted in, for example, an engine vehicle. A lead battery is used. The high voltage battery 21 and the 12V battery 22 are connected via a DC branch harness 25 ″, a DC / DC converter 37, and a battery harness 38. The DC / DC converter 37 changes the voltage of several hundred volts from the high voltage battery 21 to 12V. The DC / DC converter 37 is controlled by the hybrid control module 81 to manage the charge amount of the 12V battery 22.

  The capacitor 23 is a power storage device mounted as a dedicated power source for the starter motor 1 and has a large electrostatic capacity and has an excellent rapid charging / discharging performance (eDLC: electric Double Layer Capacitor). What is called is used. The auxiliary load power supply system including the 12V battery 22 and the DC / DC converter 37 and the capacitor 23 are connected to the battery branch harness 38 ′ via the capacitor charging circuit 41. The capacitor 23 and the starter motor 1 are connected via a capacitor harness 42, a relay switch 44, and the like. The capacitor 23, the capacitor charging circuit 41 and the like constitute a DLC unit 45. Further, the hybrid control module 81 performs energization (ON) / interruption (OFF) of the relay switch 44. While the relay switch 44 is energized (turned on), the starter motor 1 is driven using the electric power of the capacitor 23.

  The capacitor charging circuit 41 is constituted by a DC / DC converter circuit (a combination circuit of a switching element, a choke coil, a capacitor and a diode) with a built-in semiconductor relay by a switching method. The capacitor charging circuit 41 includes a semiconductor relay 51 and a DC / DC converter 52 that are controlled by a hybrid control module 81. The semiconductor relay 51 is a non-contact relay using a semiconductor switching element, and has a configuration using, for example, an optical semiconductor called a photocoupler that transmits an isolated input / output space by a light signal. The semiconductor relay 51 has a switch function for disconnecting or connecting the capacitor 23 from the auxiliary load power supply system including the 12V battery 22 and the DC / DC converter 37 and the like. The DC / DC converter 52 subdivides the input direct current into pulse currents by a switching element and connects them to obtain a direct current output of a necessary voltage, thereby converting a 12V direct current to a 13.5V direct current and a capacitor. Has a function to switch the charging current.

[Control system configuration]
FIG. 1 shows an overall system of an FF plug-in hybrid vehicle. Hereinafter, the control system configuration of the FF plug-in hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the control system includes a hybrid control module 81 (abbreviation: “HCM”) as an integrated control unit having a function of appropriately managing energy consumption of the entire vehicle. Control means connected to the hybrid control module 81 include an engine control module 82 (abbreviation: “ECM”), a motor controller 83 (abbreviation: “MC”), and a CVT control unit 84 (abbreviation: “CVTCU”). Have. The data communication module 85 (abbreviation: “DCM”) and the lithium battery controller 86 (abbreviation: “LBC”) are included. These control means include CAN communication line 90 (CAN is an abbreviation for “Controller Area Network”) except for a LIN communication line 89 (LIN: abbreviation for “Local Interconnect Network”) that connects hybrid control module 81 and DLC unit 45. Is connected so that bidirectional information can be exchanged.

  The hybrid control module 81 performs various controls based on input information from each control means, an ignition switch 91, an accelerator opening sensor 92, a vehicle speed sensor 93, an accelerator pedal sensor 95, and the like. Among these, the control performed for the purpose of driving the FF plug-in hybrid vehicle capable of external charging with high fuel efficiency is a travel mode based on the battery SOC of the high-power battery 21 (“CD mode”, “CS mode”). Selection control.

  The “CD mode (Charge Depleting mode)” is a mode in which priority is given to EV travel that consumes the power of the high-power battery 21 in principle. For example, while the battery SOC of the high-power battery 21 decreases from full SOC to set SOC. Is selected. However, HEV traveling is exceptionally performed in high-load traveling where driving force is insufficient in EV traveling. The start of the horizontal engine 2 during the selection of the “CD mode” is based on start by the starter motor 1 (starter start), with the exception of start by the motor / generator 4 (high power start, M / G start).

  The “CS mode (Charge Sustain mode)” is a mode in which priority is given to HEV running that maintains the power of the high-power battery 21 in principle, and is selected when the battery SOC of the high-power battery 21 is equal to or lower than the set SOC. That is, when it is necessary to maintain the battery SOC of the high-power battery 21 within a predetermined range, HEV traveling is performed by engine power generation that causes the motor / generator 4 to generate electric power by driving the lateral engine 2. The start of the horizontal engine 2 during the selection of the “CS mode” is based on the start by the motor / generator 4 (high power start, M / G start), with the exception of the start by the starter motor 1 (starter start). It should be noted that the “set SOC” that is the mode switching threshold value has hysteresis between the value when the CD mode → CS mode and the value when the CS mode → CD mode.

The hybrid control module 81 performs engine start control. When the engine start request is made in the EV mode using the motor / generator 4 as a drive source, the engine start control is either a strong electric start using the motor / generator 4 or a starter start using the starter motor 1. It is control which uses and starts an engine.
Here, the case where the start of the engine is requested includes, for example, a case where a driving force is requested and a case where a system is requested.
The case where the driving force is requested is, for example, a case where the requested driving force requested by the driver (accelerator opening APO by the driver's accelerator pedal operation) exceeds the upper limit driving force that the motor / generator 4 can output. is there. Even if the accelerator opening APO is constant, the vehicle speed VSP increases, resulting in a driving force request.
The case of the system request includes, for example, a request for charging the high-power battery 21 due to a decrease in the battery SOC, or a case where the temperature of the cooling water has decreased.

  The hybrid control module 81 outputs a motor rotation number command of the motor / generator 4 to the motor controller 83 based on the input information. The hybrid control module 81 performs energization (on) / cutoff (off) control of the relay switch 44.

  In the hybrid control module 81, in addition to the above control, charge control to the capacitor 23 and discharge control from the capacitor 23 are performed.

  The engine control module 82 performs fuel injection control, ignition control, fuel cut control, and the like of the horizontal engine 2. The motor controller 83 performs powering control and regenerative control of the motor / generator 4 by the inverter 26, and manages the motor / generator temperature, the motor applied current value, and the like. The motor controller 83 performs motor rotational speed control for rotationally driving the motor / generator 4 in accordance with a motor rotational speed command from the hybrid control module 81.

  The CVT control unit 84 performs the engagement hydraulic pressure control of the first clutch 3, the engagement hydraulic pressure control of the second clutch 5, the transmission hydraulic pressure control of the belt type continuously variable transmission 6, and the like. When the switch of the portable remote control key is remotely operated and the communication is established with the portable remote control key, the data communication module 85 controls, for example, lock / unlock of the charging port lid and the connector lock mechanism. The lithium battery controller 86 (charge capacity detection means) manages the battery SOC, battery temperature, etc. of the high-power battery 21.

  FIG. 2 shows a flow of engine start control processing executed by the hybrid control module 81 (engine start control means). Hereinafter, each step of FIG. 2 showing the engine start control processing configuration will be described. The engine start control process is “START” when the EV mode using the motor / generator 4 as a drive source is selected.

  In step S1, it is determined whether there is an engine start request. If YES (engine start request is present), the process proceeds to step S10. If NO (engine start request is not present), step S1 is repeated.

  In step S10, following the determination that there is an engine start request in step S1, it is determined whether or not the vehicle speed VSP is zero based on the input information from the vehicle speed sensor 93. If YES (VSP = 0), the process proceeds to step S20. If NO (VSP> 0), the process proceeds to step S30.

  In step S20, following the determination of “VSP = 0” in step S10, it is determined whether or not there is an intention of acceleration (hereinafter referred to as “acceleration intention of driver”) based on the rapid acceleration determination, that is, the driver's accelerator depression operation speed. (Acceleration intention determination means). If YES (the driver intends to accelerate), the process proceeds to step S24. If NO (the driver does not intend to accelerate), the process proceeds to step S25. This acceleration intention determination processing flow is shown in the flowchart of FIG. 3 (acceleration intention determination means). Hereinafter, each step (step S21 to step S23) of FIG. 3 representing the acceleration intention determination processing configuration in step S20 will be described.

In step S21, based on the input information from the accelerator opening sensor 92, it is determined whether or not the accelerator opening APO is larger than a predetermined accelerator opening (accelerator opening determining unit). For example, when the accelerator opening is set to 8 steps, it is determined whether or not the input information from the accelerator opening sensor 92 is larger than 4 steps (predetermined accelerator opening). If YES (APO> 4/8), the process proceeds to step S22. If NO (APO ≦ 4/8), the process proceeds to “no driver acceleration intention”, that is, to step S25 in FIG.
Here, the predetermined accelerator opening is set to the accelerator opening APO corresponding to the vehicle speed VSP when the “EV mode” is switched to the “HEV mode” by the accelerator depression operation.

In step S22, following the determination of “APO> 4/8” in step S21, the accelerator pedal depressing speed (hereinafter referred to as “depressed”) based on the input information (depressed amount of the accelerator pedal) from the accelerator pedal sensor. It is determined whether or not “speed” is greater than a predetermined depression speed (accelerator pedal depression speed determination unit). That is, an increase amount (depression speed) per unit time (for example, 10 ms) of the accelerator pedal depression amount is calculated, and whether or not this depression speed (accelerator depression operation speed equivalent value) is greater than a predetermined depression speed (predetermined value). Determine whether. If YES (depressing speed> predetermined depressing speed), the process proceeds to “the driver intends to accelerate”, that is, step S24 in FIG. 2, and if NO (depressing speed ≦ predetermined depressing speed), the process proceeds to step S23.
Here, the predetermined stepping speed is set in advance by a sensitivity test or the like. That is, the lower limit value is estimated and set so that the driver's required driving force is high and quick engine start is desired by changing the accelerator depressing operation speed beyond that.

In step S23, following the determination of “stepping speed ≦ predetermined stepping speed” in step S22, the amount of change in accelerator opening per unit time (for example, 10 ms) is changed from the input information from the accelerator opening sensor 92 to a predetermined change. It is determined whether it is larger than the amount (accelerator opening change amount determination unit). That is, the accelerator opening change amount (increase amount) ΔAPO per unit time of the accelerator opening is calculated, and this accelerator opening change amount ΔAPO (accelerator depression operation speed equivalent value) is larger than a predetermined change amount (predetermined value). It is determined whether or not. If YES (ΔAPO> predetermined change amount), the process proceeds to step S24 in FIG. 2, that is, if NO (ΔAPO ≦ predetermined change amount), “no driver acceleration intention”, ie, FIG. The process proceeds to step S25.
Here, the predetermined change amount is set in advance by a sensitivity test or the like. That is, the lower limit value is estimated and set so that the driver's required driving force is high and quick engine start is desired by changing the accelerator depressing operation speed beyond that.

In step S24, following the determination that the driver intends to accelerate in step S20, a starter start using the starter motor 1 is executed as a start of the horizontal engine 2, and the process proceeds to the end. In step S24, the speed ratio of the belt type continuously variable transmission 6 is not changed.
Further, a motor rotation speed command for increasing the motor rotation speed of the motor / generator 4 to the motor rotation speed that generates the engagement hydraulic pressure of the first clutch 3 is output from the hybrid control module 81 to the motor controller 83. Furthermore, the CVT control unit 84 performs engagement hydraulic pressure control of the second clutch 5 that gradually increases the transmission torque capacity of the second clutch 5 in the slip state.

  In step S25, following the determination that the driver does not intend to accelerate in step S20, a strong electric start using the motor / generator 4 is executed as a start of the horizontally placed engine 2, and the process proceeds to the end.

In step S30, following the determination of “VSP> 0” in step S10, the differential rotation between the horizontally placed engine 2 and the motor / generator 4 with the first clutch 3 sandwiched when the engine is requested is greater than a predetermined differential rotation. It is determined whether or not. That is, a differential rotation between the horizontal engine 2 and the motor / generator 4 with the first clutch 3 interposed therebetween (hereinafter simply referred to as “differential rotation”) is calculated from the rotational speeds of the horizontal engine 2 and the motor / generator 4. (Differential rotation calculation means). Note that when the engine is requested to start, the rotational speed of the horizontal engine 2 is zero, so the differential rotation is equal to the motor rotational speed of the motor / generator 4 (differential rotation = motor rotational speed). It is determined whether or not this differential rotation is greater than a predetermined differential rotation. If YES (differential rotation> predetermined differential rotation), the process proceeds to step S40. If NO (differential rotation ≦ predetermined differential rotation), the process proceeds to step S70.
Here, the predetermined differential rotation is set according to the engine start time in consideration of the shift time. The engine start time is the time from when the engine is started until the lockup of the first clutch 3 is completed.

  In step S40, following the determination of “differential rotation> predetermined differential rotation” in step S30, a rapid acceleration determination, that is, whether or not the driver intends to accelerate (acceleration intention determination means) is determined. If YES (the driver has an intention to accelerate), the process proceeds to step S60. If NO (the driver has no intention to accelerate), the process proceeds to step S50. This acceleration intention determination processing flow is shown in the flowchart of FIG. 3 (acceleration intention determination means). Hereinafter, each step (step S41 to step S43) of FIG. 3 showing the configuration of the acceleration intention determination process in step S40 will be described.

  In step S41, if YES (APO> 4/8), the process proceeds to step S42, and if NO (APO ≦ 4/8), “no driver acceleration intention”, ie, the process proceeds to step S50 in FIG. The description is omitted because it is the same as S21.

  In step S42, if YES (depressing speed> predetermined depressing speed), “the driver intends to accelerate”, that is, proceed to step S60 in FIG. 2, and if NO (depressing speed ≦ predetermined depressing speed), proceed to step S43. Since other than that is the same as step S22, the description is omitted.

  In step S43, if YES (ΔAPO> predetermined change amount), the process proceeds to step S60 in FIG. 2, that is, if NO (ΔAPO ≦ predetermined change amount), “no driver acceleration intention exists”. That is, the process is the same as step S23 except that the process proceeds to step S50 in FIG.

  In step S50, following the determination that the driver does not intend to accelerate in step S40, an after-start assist margin determination is performed. That is, as the assist margin determination after starting, it is determined whether or not there is an assist margin for torque assisting the horizontal engine 2 by the motor / generator 4 after the horizontal engine 2 is started based on the state of the high-power battery 21 (after-start assist margin). Determination means). If YES (with assist margin), the process proceeds to step S60, and if NO (no assist margin), the process proceeds to step S80. The after-start assist margin determination processing flow is shown in the flowchart of FIG. 4 (after-start assist margin determination means). Hereinafter, each step (step S51 to step S53) of FIG. 4 showing the post-start assist margin determination processing configuration will be described.

  In step S51, it is determined whether or not the battery charge capacity (battery SOC) monitored by the lithium battery controller 86 is greater than a predetermined battery SOC. If YES (battery SOC> predetermined battery SOC), the process proceeds to step S52. If NO (battery SOC ≦ predetermined battery SOC), the process proceeds to “no assist margin”, that is, to step S80 in FIG.

  In step S52, following the determination of “battery SOC> predetermined battery SOC” in step S51, it is determined whether or not the battery temperature monitored by the lithium battery controller 86 is within a predetermined battery temperature range. If YES (within a predetermined battery temperature range), the process proceeds to step S53. If NO (outside the predetermined battery temperature range), the process proceeds to “no assist margin”, that is, to step S80 in FIG.

  In step S53, following the determination in the predetermined battery temperature range in step S52, it is determined whether or not the motor / generator temperature (M / G temperature) monitored by the motor controller 83 is less than the predetermined M / G temperature. . If YES (M / G temperature <predetermined M / G temperature), “there is an assist margin”, that is, proceed to step S60. If NO (M / G temperature ≧ predetermined M / G temperature), “no assist margin” That is, the process proceeds to step S80 in FIG.

  In step S60, following the determination of the driver's intention to accelerate in step S40 or the determination of “with assist margin” in step S50, an upshift of the gear ratio of the belt type continuously variable transmission 6 is performed, A starter start using the starter motor 1 is executed as a start of the horizontal engine 2 and the process proceeds to the end.

In step S70, following the determination of “differential rotation ≦ predetermined differential rotation” in step S30, the surplus torque that can be output by the motor / generator 4 calculated from the upper limit torque that can be output by the motor / generator 4 and the actual torque. Is less than a predetermined margin torque (margin torque determination means). That is, the surplus torque that can be output by the motor / generator 4 is calculated from the upper limit torque that can be output by the motor / generator 4 and the actual torque estimated from the motor applied current value. It is determined whether or not the calculated margin torque is less than a predetermined margin torque. If YES (margin torque <predetermined margin torque, no margin torque), the process proceeds to step S80. If NO (margin torque ≧ predetermined margin torque, with margin torque), the process proceeds to step S90.
Here, the predetermined margin torque is a torque that can be output by the motor / generator 4 in order to execute the high-voltage start using the motor / generator 4 as the start of the horizontally placed engine 2.

  In step S80, following the determination of “no assist margin” in step S50 or the determination of “no margin torque” in step S70, a starter start using the starter motor 1 is executed as a start of the horizontal engine 2. Go to the end. In step S80, the speed ratio of the belt type continuously variable transmission 6 is not changed.

  In step S90, following the determination of “with surplus torque” in step S70, a strong electric start using the motor / generator 4 is executed as a start of the horizontally placed engine 2, and the process proceeds to the end.

Next, the operation will be described.
The effects of the control device for the FF plug-in hybrid vehicle of the first embodiment are as follows: “engine start control processing operation when starting at zero vehicle speed”, “basic engine start control processing operation during EV travel”, “first operation during EV travel” 1 ”engine start control processing operation”, “second engine start control processing operation during EV travel”, “third engine start control processing operation during EV travel”, “post-start assist margin information during EV travel” The explanation will be divided into “the engine start control function used”.

[Engine start control processing when the vehicle starts at zero speed]
In the engine start control, when there is an engine start request in the EV mode, the engine is started using either a starter start using the starter motor 1 or a strong electric start using the motor / generator 4.

  In the starter start, based on the output of the starter start command from the hybrid control module 81, the relay switch 44 is turned on (energized). As a result, the starter motor 1 using the capacitor 23 as a power source rotates the crankshaft of the horizontal engine 2 to start the starter, and turns off the relay switch 44 after a predetermined time from energization. That is, in the engine start control by the starter motor 1, the starter motor 1 is driven using the electric power of the capacitor 23 while the relay switch 44 is turned on (energized) by the starter start command, and the horizontally placed engine 2 is started.

  In the high-power start (M / G start), the horizontal engine 2 is started by using the motor / generator 4 that uses the high-power battery 21 as a power source and cranking the horizontal engine 2 to start M / G. In this M / G start control, the second clutch 5 is brought into a slip state and the first clutch 3 is gradually engaged, whereby the motor / generator 4 is used as a starter motor and the horizontally placed engine 2 is cranked.

  First, the engine start control processing operation when the vehicle speed VSP is zero in the engine start control will be described.

  The control for executing the starter start when the engine start request is made and the vehicle speed VSP is zero is a flow of START → step S1 → step S10 → step S20 → step S24 → END in the flowchart of FIG. That is, in the EV mode, when there is an engine start request and the vehicle speed VSP is zero, that is, when starting from the vehicle speed zero, if it is determined that the driver intends to accelerate, starter start is executed.

  In the flowchart of FIG. 2, the control for executing the strong electric start when there is an engine start request and the vehicle speed VSP is zero is a flow that proceeds from START → step S1 → step S10 → step S20 → step S25 → END. That is, in the EV mode, when there is an engine start request and the vehicle speed VSP is zero, that is, when starting from the vehicle speed zero, when it is determined that the driver does not intend to accelerate, the high-voltage start is executed.

"Basic engine start control processing operation during EV travel"
Next, a basic engine start control processing operation when there is an engine start request during EV traveling in the engine start control will be described with reference to the engine start region maps of FIGS. This basic engine start control is determined from the differential rotation and the surplus torque. 5, the vertical axis represents the motor actual torque of the motor / generator 4, and the horizontal axis represents the actual motor rotation speed of the motor / generator 4.

  When there is an engine start request during EV traveling, the differential rotation is determined to be less than the predetermined differential rotation, and when it is determined that there is a surplus torque, the high-voltage start region of FIG. 5 is entered. That is, the control for executing the high-power start is a flow that proceeds from START → step S1 → step S10 → step S30 → step S70 → step S90 → END in the flowchart of FIG. Generally, when there is an engine start request during EV traveling, a strong electric start is performed.

  When there is an engine start request during EV travel, if the differential rotation is determined to be less than the predetermined differential rotation and it is determined that there is no extra torque, the starter start (no shift) region of FIG. That is, the control for executing starter start (no shift) is a flow that proceeds from START → step S1 → step S10 → step S30 → step S70 → step S80 → END in the flowchart of FIG. That is, when there is an engine start request during EV traveling, the starter is started if the motor / generator 4 does not have a surplus torque that can be output for a strong electric start.

  When there is an engine start request during EV travel, if it is determined that the differential rotation is greater than the predetermined differential rotation, the starter start (upshift) region of FIG. 5 is entered. That is, the control for executing starter start (upshift) is a flow that proceeds from START → step S1 → step S10 → step S30 → (step S40 →) step S60 → END in the flowchart of FIG.

The reason for executing the upshift as well as the starter start will be described with reference to FIG. FIG. 6 shows the motor speed and the engine speed of the motor / generator 4 with the first clutch 3 sandwiched from when the engine start is requested (an example). Time zero is when an engine start is requested. MRn (n is a number) indicates the motor speed. A constant slope (solid line) of MRn descending to the left indicates the shift speed of the continuously variable transmission CVT, and a broken line indicates a case where no shift is performed. ERn (n is a number) is a target rotational speed at which the lockup of the first clutch 3 can be started at the highest speed by shifting the speed of MRn. In FIG. 6, it is a condition that lock-up of the first clutch 3 is started by a predetermined time (time).
In this case, MR1 and MR2 satisfy this condition even if there is no speed change (broken line). That is, when the motor rotation speed is lower than the predetermined motor rotation speed (here, the motor rotation speed of MR2 at time zero), the lock-up can be started by a predetermined time without shifting. it can. On the other hand, MR3 to MR5 cannot satisfy the conditions unless they are shifted (solid line). That is, since the lockup cannot be started by a predetermined time, when the motor speed is high, it is necessary to shift (upshift) and lower the motor speed. For this reason, when the motor rotation speed is higher than the predetermined motor rotation speed, the upshift is executed so that the lockup can be started by a predetermined time. That is, it is necessary to set a predetermined differential rotation (= predetermined motor rotation number) and execute an upshift as well as starter start (starter start (upshift) region in FIG. 5).
Further, if the predetermined motor rotation speed is reduced, the predetermined time can be shortened. However, if the predetermined motor rotation speed in FIG. Can't start its lockup. For this reason, the predetermined differential rotation is set according to the engine start time in consideration of the shift time.

  Basic engine start control when there is an engine start request during EV travel is controlled by rapid acceleration determination (step S30) and post-start assist margin determination (step S40).

[First engine start control processing operation during EV travel]
Next, the first engine start control processing operation at the time of determination of the presence of acceleration in the engine start control at the time of engine start request during EV traveling and when it is determined that the differential rotation is greater than the predetermined differential rotation ,explain.

  When it is determined that the driver intends to accelerate when the engine is started during EV travel, the starter start control is performed in the flow chart of FIG. 2 by START → step S1 → step S10 → step S30 → step S40 → step S60. → The flow goes to END. That is, when there is an engine start request during EV traveling and it is determined that the differential rotation is greater than the predetermined differential rotation, and it is determined that the driver intends to accelerate, an upshift is executed and a starter start is executed .

When it is determined that the driver intends to accelerate, there are two flows in the flowchart of FIG.
One is a flow that proceeds from step S40 → step S41 → step S42 → “there is a driver acceleration intention”. That is, in the flowchart of FIG. 3, it is determined that the accelerator opening is larger than the predetermined accelerator opening, and the stepping speed is determined to be larger than the predetermined stepping speed.
The other is a flow that proceeds from step S40 → step S41 → step S42 → step S43 → “the driver intends to accelerate”. That is, it is a case where it is determined that the accelerator opening is larger than the predetermined accelerator opening, and it is determined that the accelerator opening change amount is larger than the predetermined change amount.
That is, it is determined that the driver intends to accelerate by any one of the above determinations.

Next, the first engine start control processing operation during EV traveling will be described for each time based on the operation example shown in the time chart of FIG. The vertical axis in FIG. 7 represents the accelerator opening APO and the vehicle speed VSP, the engine speed of the horizontal engine 2 (ICE, solid line), the motor speed of the motor / generator 4 (MOT, broken line), and Primary rotation speed of primary pulley PrP (PrP, one-dot chain line), engine torque of horizontal engine 2 (ICE, solid line), motor torque of motor / generator 4 (MOT, broken line), primary torque of primary pulley PrP (PrP, Starter motor torque (starter, two-dot chain line) of the starter motor, transmission torque capacity of the first clutch 3 (CL1 capacity), transmission torque capacity of the second clutch 5 (CL2 capacity), front and rear of the vehicle Acceleration G is shown. The horizontal axis in FIG. 7 represents time, and “t” represents the time. As for the torque, the plus side is the driving torque, and the torque less than 0 is a load with respect to the driving torque.
In the time charts of FIGS. 8 and 9 to be described later, the description of the vertical axis and the horizontal axis is the same. In FIGS. 8 and 9, the same time t as FIG. 7 represents the same time.
Hereinafter, each step will be described based on the time chart of FIG.

  At time t0, since the vehicle speed is greater than zero and the engine speed is zero, the vehicle is running on EV. This time corresponds to “START” in the flowchart of FIG. Further, since the vehicle is running on EV, the second clutch 5 is engaged. The accelerator opening is 2.

  From time t0 to time t1, the accelerator pedal is stepped on by the driver immediately before time t1, and the accelerator opening is rapidly increased from 2 to 8.

  At time t1, when the accelerator opening reaches the maximum of 8, an engine start request is made by a driving force request (START → step S1). Further, the vehicle speed VSP is greater than zero (step S10). At this time, the differential rotation at the time of the engine start request is equal to the motor rotation speed because the engine rotation speed is zero as shown in FIG. That is, the motor rotational speed at the time of engine start request during EV traveling is larger than the rotational speed corresponding to the predetermined differential rotation (step S30). Since the accelerator opening is 8, “APO> 4/8” (step S41) and at this time, it is determined that “stepping speed> predetermined stepping speed” (step S42). It is determined that there is (step S40). In other words, upshift is executed and starter start (step S60) is used as engine start. Thereby, control of said step S60 is started. This corresponds to the flow of START → step S1 → step S10 → step S30 → step S40 → step S60 → END in FIG. Also, slip-in control is started.

  From time t1 to time t2, so-called backlash, in which the plate gap of the opened multi-plate friction clutch (first clutch 3) is closed by precharging in the transmission torque capacity of the first clutch 3, is performed. By setting the precharge to the standby state, the first clutch 3 is brought into a state immediately before the start of engagement. Further, the transverse engine 2 is cranked by the rotational drive (starter motor torque) of the starter motor 1. At this time, slip-in control is performed. That is, the motor rotational speed is increased from the primary rotational speed, a certain difference is made between the motor rotational speed and the primary rotational speed, the second clutch 5 is brought into the slip state, and the torque fluctuation when the first clutch 3 is engaged is changed. Prepare for absorption. Further, the engagement hydraulic pressure control of the second clutch 5 is performed so that the transmission torque capacity of the second clutch 5 in the slip state corresponds to the required driving force. That is, control for gradually increasing the transmission torque capacity of the second clutch 5 is performed.

  At time t2, an upshift is executed. That is, the CVT control unit 84 controls the shift hydraulic pressure of the belt type continuously variable transmission 6 and starts control for upshifting the gear ratio. And the input rotation speed of the belt-type continuously variable transmission 6 is reduced by upshifting. For this reason, a primary rotation speed falls with a motor rotation speed. Before and after time t2, a shock is generated in the vehicle due to a change in the longitudinal acceleration G (region G1) due to the inertia torque of the primary pulley PrP. Even if such a shock occurs, the driver does not feel uncomfortable by determining that the driver intends to accelerate. At this time, the slip-in control is terminated. The engine is also cranking.

  From time t2 to time t3, due to the execution of upshifting, the primary rotation speed gradually decreases along with the motor rotation speed (until time t4). At this time, the motor torque and the primary torque are increased based on the increase in the engagement capacity of the second clutch 5 (until time t4). Further, the horizontal engine 2 is being cranked.

  At time t3, the engine speed reaches a speed at which the initial explosion can be performed by cranking (ICE first explosion possible speed), and the horizontal engine 2 is initially exploded by fuel injection and ignition.

  From time t3 to time t4, the engine speed increases due to the first explosion of the horizontally placed engine 2. When the starter motor torque becomes zero, the horizontal engine 2 enters a self-sustaining operation state due to complete explosion. From just before time t4 to time t4, a shock is generated in the vehicle due to a change in the longitudinal acceleration G (region G1) due to the inertia torque of the primary pulley PrP.

  At time t4, since the motor rotational speed has been lowered to the target slip rotational speed, the upshift is terminated and the motor rotational speed is maintained at the target slip rotational speed. At this time, the motor torque and the primary torque have reached the upper limit torque (MOT output possible upper limit torque) that the motor / generator 4 can output.

  From time t4 to time t5, the engine speed increases with time, and the differential rotation between the engine speed and the motor speed across the first clutch 3 is almost eliminated.

  At time t5, there is no differential rotation between the engine speed and the motor speed across the first clutch 3, and lockup of the first clutch 3 is started. That is, the engagement hydraulic pressure control of the first clutch 3 that gradually increases the transmission torque capacity of the first clutch 3 is started.

  From time t5 to time t6, the transmission torque capacity of the first clutch 3 is gradually increased. Then, immediately before time t6, the differential rotation between the engine speed and the motor speed across the first clutch 3 gradually disappears.

  At time t6, the rotational speed becomes the synchronous rotational speed at which the differential rotational speed between the engine rotational speed and the motor rotational speed with the first clutch 3 interposed therebetween is eliminated, and the lockup (complete engagement) of the first clutch 3 is completed. At this time, slipout is started.

  From time t6 to time t7, slip-out control is performed.

  At time t7, the slip-out control is finished and the lockup of the second clutch 5 is started. That is, the engagement hydraulic pressure control of the second clutch 5 that gradually increases the transmission torque capacity of the second clutch 5 is started.

  From time t7 to time t8, the transmission torque capacity of the second clutch 5 is gradually increased.

  At time t8, all the rotation speeds are synchronized, and the lockup (complete engagement) of the second clutch 5 is completed. At this time, the mode shifts to the “HEV mode”, returns to the normal shift control, and downshift is executed.

  From time t8 to time t9, the primary torque gradually increases and becomes larger than the MOT output possible upper limit torque. At this time, all the rotational speeds are increased by the downshift. In addition, the vehicle speed VSP is increasing.

At the time t9, all the rotation speeds and the vehicle speed VSP are increasing.
Note that the period from time t1 is the “EV mode”, the period from time t1 to time t8 is the transition from the “EV mode” to the “HEV mode”, and the period is from the time t8 to the “HEV mode”.

[Second engine start control processing operation during EV travel]
Next, in the engine start control at the time of engine start request during EV traveling and when it is determined that the differential rotation is greater than the predetermined differential rotation, the second in the determination that there is no intention to accelerate but there is an assist margin determination The engine start control processing operation will be described.

  When it is determined that the driver does not intend to accelerate and the assist margin is determined at the time of engine start request during EV traveling, the starter start control is performed in the flow chart of FIG. 2 by START → step S1 → step S10 → step. The flow proceeds from S30 to step S40 to step S50 to step S60 to END. That is, when there is an engine start request during EV traveling, it is determined that the differential rotation is greater than the predetermined differential rotation, it is determined that the driver does not intend to accelerate, and if it is determined that there is an assist margin, an upshift is executed. At the same time, starter start is executed.

When it is determined that the driver does not intend to accelerate, there are two flows in the flowchart of FIG.
One is a flow that proceeds from step S40 to step 41 to "no driver acceleration intention". That is, it is a case where it is determined in the flowchart of FIG. 3 that the accelerator opening is equal to or less than a predetermined accelerator opening.
The other is a flow from step S40 → step S41 → step S42 → step S43 → “no driver acceleration intention”. That is, it is a case where it is determined that the accelerator opening is larger than the predetermined accelerator opening, the stepping speed is determined to be less than the predetermined stepping speed, and the accelerator opening change amount is determined to be less than the predetermined change amount.
That is, it is determined that the driver does not intend to accelerate by any one of the above determinations.

  If it is determined that there is an assist margin, the flow proceeds from step S50 → step S51 → step S52 → step S53 → “with assist margin” in the flowchart of FIG. That is, in the flowchart of FIG. 3, it is determined that the battery SOC is greater than the predetermined battery SOC, the battery temperature is determined to be within the predetermined battery temperature range, and the M / G temperature is determined to be less than the predetermined M / G temperature. If it is determined, there is an assist margin.

Next, the second engine start control processing operation during EV traveling will be described for each time based on the operation example shown in the time chart of FIG.
Hereinafter, each step will be described based on the time chart of FIG.

  At time t0, since the vehicle speed VSP is greater than zero and the engine speed is zero, the vehicle is running on EV. This time corresponds to “START” in the flowchart of FIG. Further, since the vehicle is running on EV, the second clutch 5 is engaged. Further, the accelerator opening is 4, and in this time chart, it is constant even if time elapses.

  From time t0 to time t1, the accelerator opening is a constant 4, but the vehicle speed VSP is increasing. Further, the rotational speed is also increased due to the increase in torque.

  At time t1, even if the accelerator opening APO is constant, the vehicle speed VSP increases, and an engine start request due to a driving force request is made (START → step S1). Further, the vehicle speed VSP is greater than zero (step S10). At this time, the differential rotation at the time of the engine start request is equal to the motor rotation speed because the engine rotation speed is zero as shown in FIG. That is, the motor rotational speed at the time of engine start request during EV traveling is larger than the rotational speed corresponding to the predetermined differential rotation (step S30). Since the accelerator opening is 4, it is determined that “APO ≦ 4/8” (step S41), and therefore it is determined that the driver does not intend to accelerate (step S40). At this time, it is determined that “battery SOC> predetermined battery SOC” (step S51), “inside the predetermined battery temperature range” (step S52), and “M / G temperature <predetermined M / G temperature”. Since it is determined (step S53), it is determined that there is an assist margin (step S50). In other words, upshift is executed and starter start (step S60) is used as engine start. Thereby, control of said step S60 is started. This corresponds to the flow of START → step S1 → step S10 → step S30 → step S40 → step S50 → step S60 → END in FIG. Also, slip-in control is started.

  From time t1 to time t6, except for the vehicle speed VSP and the longitudinal acceleration G, it is the same as the same time in FIG. However, the timing at which the change in the longitudinal acceleration G (region G1) due to the inertia torque of the primary pulley PrP occurs is the same as in FIG.

  At time t6, the rotational speed becomes the synchronous rotational speed at which the differential rotational speed between the engine rotational speed and the motor rotational speed with the first clutch 3 interposed therebetween is eliminated, and the lockup (complete engagement) of the first clutch 3 is completed. At this time, after the lockup (complete engagement) of the first clutch 3 is completed, the assist of the engine torque is started by the motor torque corresponding to the assist margin, that is, the MOT output possible upper limit torque. Also, slip-out is started. At this time, the engine torque is kept low.

  From time t6 to time t7, the engine torque is assisted by the motor torque for the assist margin (until time t8). At this time, the engine torque is kept low (until time t8). Also, slip-out control is performed.

  At time t7, the slip-out control is finished and the lockup of the second clutch 5 is started. That is, the engagement hydraulic pressure control of the second clutch 5 that gradually increases the transmission torque capacity of the second clutch 5 is started.

  From time t7 to time t8, the transmission torque capacity of the second clutch 5 is gradually increased.

  At time t8, all the rotation speeds are synchronized, and the lockup (complete engagement) of the second clutch 5 is completed. At this time, the mode shifts to the “HEV mode”, returns to the normal shift control, and downshift is executed.

  From time t8 to time t9, the motor torque gradually decreases and the engine torque gradually increases. At this time, all the rotational speeds are increased by the downshift. In addition, the vehicle speed VSP is increasing.

At the time t9, all the rotation speeds and the vehicle speed VSP are increasing. Further, the engine torque is obtained from time t9.
Note that the period from time t1 is the “EV mode”, the period from time t1 to time t8 is the transition from the “EV mode” to the “HEV mode”, and the period is from the time t8 to the “HEV mode”.

[Third engine start control processing operation during EV travel]
Next, in the engine start control at the time of engine start request during EV travel and when it is determined that the differential rotation is greater than the predetermined differential rotation, the third in the determination of no acceleration intention and the determination of no assist margin The engine start control processing operation will be described.

  When it is determined that there is no acceleration intention of the driver and it is determined that there is no assist margin at the time of engine start request during EV traveling, the control to execute starter start is START → step S1 → step S10 → step in the flowchart of FIG. The flow proceeds from S30 to step S40 to step S50 to step S80 to END. That is, when there is an engine start request during EV travel, it is determined that the differential rotation is greater than the predetermined differential rotation, it is determined that the driver does not intend to accelerate, and if it is determined that there is no assist margin, the gear is not shifted (belt The gear ratio of the variable continuously variable transmission 6 is not changed.) Starter start is executed.

When it is determined that there is no assist margin, in the flowchart of FIG. 3, the flow proceeds from “NO” to “no assist margin” in any step of step S50 → step S51 to step S53. That is, in the flowchart of FIG. 3, when it is determined that the battery SOC is smaller than the predetermined battery SOC, when the battery temperature is determined to be outside the predetermined battery temperature range, or when the M / G temperature is the predetermined M / G When it is determined that the temperature is equal to or higher than the G temperature, it is determined that there is no assist margin.
The case where it is determined that the driver does not intend to accelerate is as described above.

Next, the third engine start control processing operation during EV traveling will be described for each time based on the operation example shown in the time chart of FIG.
Hereinafter, each step will be described based on the time chart of FIG.

  The time t0 and the time t0 to the time t1 are the same as the same time in FIG.

  At time t1, even if the accelerator opening APO is constant, the vehicle speed VSP increases, and an engine start request due to a driving force request is made (START → step S1). Further, the vehicle speed VSP is greater than zero (step S10). At this time, the differential rotation at the time of the engine start request is equal to the motor rotation speed because the engine rotation speed is zero as shown in FIG. That is, the motor rotational speed at the time of engine start request during EV traveling is larger than the rotational speed corresponding to the predetermined differential rotation (step S30). Since the accelerator opening is 4, it is determined that “APO ≦ 4/8” (step S41), and therefore it is determined that the driver does not intend to accelerate (step S40). At this time, “battery SOC ≦ predetermined battery SOC” (step S51), “outside the predetermined battery temperature range” (step S52), or “M / G temperature ≧ predetermined M / G temperature” (step S53) Since it is determined that any of these is applicable, it is determined that there is no assist margin (step S50). That is, the starter start (step S60) is used as the engine start without shifting. Thereby, control of said step S80 is started. This corresponds to the flow of START → step S1 → step S10 → step S30 → step S40 → step S50 → step S80 → END in FIG. Also, slip-in control is started.

  Since time t1 to time t2 are the same as the same time in FIG.

  At time t2, the description is omitted because it is the same as the same time in FIG.

  From time t2 to time t3, since there is no speed change, the motor rotation speed and the primary rotation speed are constant from the time t2. At this time, the states of the motor / generator 4, the high-power battery 21, etc., that is, “battery SOC ≦ predetermined battery SOC” (step S 51), “outside the predetermined battery temperature range” (step S 52), and “M / G temperature” It is determined that at least one of “≧ predetermined M / G temperature” (step S53) is applicable. For this reason, the motor / generator 4 is limited by the motor torque, and the motor torque does not increase but gradually decreases. Since other than this is the same as that at the same time in FIG.

  At time t3, time t3 to time t4, and time t4, except that the gear is not shifted, the motor rotation speed and the primary rotation speed are constant from the time t2, and the motor torque is reduced, FIG. The description is omitted because it is the same as the same time.

  From time t4 to time t6 ', the engine speed increases with time.

  At time t6 ', the differential rotation between the engine speed and the motor speed across the first clutch 3 is almost eliminated, and the lockup of the first clutch 3 is started. That is, the engagement hydraulic pressure control of the first clutch 3 that gradually increases the transmission torque capacity of the first clutch 3 is started.

  From time t6 'to time t7, the transmission torque capacity of the first clutch 3 is gradually increased. Then, the differential rotation between the engine speed and the motor speed across the first clutch 3 gradually disappears.

  At time t7, the rotational speed becomes a synchronous rotational speed at which the differential rotational speed between the engine rotational speed and the motor rotational speed with the first clutch 3 interposed therebetween is eliminated, and the lockup (complete engagement) of the first clutch 3 is completed. That is, the lockup (complete engagement) of the first clutch 3 is completed on the higher rotation side than the rotation speed corresponding to the predetermined differential rotation. At this time, since there is no assist margin in the motor torque, the engine torque is not assisted by the motor torque. Also, slip-out is started.

  From time t7 to time t7 ', slip-out control is performed.

  At time t7 ', the slip-out control is finished, and the lockup of the second clutch 5 is started. That is, the engagement hydraulic pressure control of the second clutch 5 that gradually increases the transmission torque capacity of the second clutch 5 is started.

  From time t7 'to time t8, the transmission torque capacity of the second clutch 5 is gradually increased.

  At time t8, all the rotation speeds are synchronized, and the lockup (complete engagement) of the second clutch 5 is completed. At this time, the mode shifts to the “HEV mode”, returns to the normal shift control, and downshift is executed.

  From time t8 to time t9, the motor torque gradually decreases. All speeds and vehicle speed VSP are increasing.

At the time t9, all the rotation speeds and the vehicle speed VSP are increasing. Further, the engine torque is obtained from time t9.
Note that the period from time t1 is the “EV mode”, the period from time t1 to time t8 is the transition from the “EV mode” to the “HEV mode”, and the period is from the time t8 to the “HEV mode”.

[Engine start control action using assist margin information after start during EV travel]
For example, a hybrid vehicle including an engine, a motor generator (traveling motor), a transmission between the motor generator and driving wheels, and a control device that starts the engine by the motor generator is used as a comparative example. According to the hybrid vehicle of this comparative example, the torque after the engine and the motor generator are fastened always relies on the engine torque.

  However, in the hybrid vehicle of the comparative example, even if the battery SOC is relatively high (including the battery temperature) and the engine torque can be assisted by the motor torque after the engagement, the torque after the engagement is converted into the motor torque. Always rely on engine torque without assistance. For this reason, an engine load becomes high and a fuel consumption may deteriorate.

  Thus, since the torque after fastening always depends on the engine torque, there is a problem that the engine load becomes high and the fuel consumption may be deteriorated.

  In contrast, in the first embodiment, when there is an engine start request during EV travel (FIG. 2, START → step S1 → step S10), the hybrid control module 81 (engine start control means, FIG. 2) has an assist margin. (Step S50 in FIG. 2), an upshift is executed (step S60 in FIG. 2, time t2 to time t4 in FIG. 8), and engine start is executed (step S60 in FIG. 2). The configuration of time t1 to time t3) in FIG. 8 was adopted.

  That is, when it is determined that there is an assist margin at the time of engine start request during EV traveling, an upshift is performed to reduce the input rotational speed (= motor rotational speed) of the transmission (FIG. 2, START → step S1 → Step S10 → Step S30 → Step S40 → Step S50 → Step S60 → END). For this reason, since the transverse engine 2 and the motor / generator 4 are engaged by the first clutch 3 on the lower rotation side than when no speed change is made (FIG. 8, time t6), the engine torque is kept low. Further, after the first clutch 3 is engaged, the engine torque can be assisted by the motor torque for the assist margin (FIG. 8, time t6 to time t8). That is, the engine load after the engine is started is reduced, and deterioration of fuel consumption is suppressed.

  As a result, when it is determined that there is an assist margin for an engine start request during EV traveling, it is possible to suppress deterioration in fuel consumption after engine start.

In addition, in this case, the engine torque can be kept low, so that the amount of CO ₂ emission can be reduced.

  In the first embodiment, the hybrid control module 81 (engine start control means, FIG. 2) employs a configuration in which starter start is executed as engine start (step S60 in FIG. 2, time t1 to time t3 in FIG. 8).

  For this reason, if it is determined that there is an assist margin for the engine start request during EV travel (FIG. 2, step S50), starter start is executed (step S60 in FIG. 2, time t1 to time in FIG. 8). By t3), the motor torque of the motor / generator 4 is not consumed by engine start.

  As a result, the engine torque can be assisted by the motor torque for the assist margin when the engine is started during EV traveling (FIG. 8, time t6 to time t8).

  In the first embodiment, the hybrid control module 81 (engine start control means, FIG. 2) causes the differential rotation to be greater than a predetermined differential rotation when an engine start is requested during EV travel (FIG. 2, START → step S1 → step S10). Is determined (FIG. 2, step S30), and when it is determined that there is no assist margin (FIG. 2, step S50), the starter is started without shifting (step S80 in FIG. 2, time t2 in FIG. 9). The configuration to be executed (step S80 in FIG. 2, time t1 to time t3 in FIG. 9) is adopted.

  In other words, when it is determined that the differential rotation is greater than the predetermined differential rotation when the engine is started during EV traveling, no shift is performed when it is determined that there is no assist margin (such as when the battery SOC is relatively low). 2. START → Step S1 → Step S10 → Step S30 → Step S40 → Step S50 → Step S80 → END) For this reason, since the horizontal engine 2 and the motor / generator 4 are fastened by the first clutch 3 on the higher rotation side than when the upshift is executed (FIG. 9, time t7), it is easy to increase the engine torque. Become.

  As a result, it is possible to obtain acceleration corresponding to the driver request even when the assist by the motor torque cannot be expected for the engine start request during EV traveling.

  In addition, in this case, the starter start is executed (step S80 in FIG. 2, time t1 to time t3 in FIG. 9), so that the horizontally placed engine 2 can be surely operated without depending on the motor torque with no assist margin. Can be started.

  In the first embodiment, the hybrid control module 81 (engine start control means, FIG. 2) causes the differential rotation to be greater than a predetermined differential rotation when an engine start is requested during EV travel (FIG. 2, START → step S1 → step S10). (FIG. 2, step S30), and when it is determined that the driver does not intend to accelerate (FIG. 2, step S40), and when it is determined that there is an assist margin (FIG. 2, step S50), an upshift is performed. Is executed (step S60 in FIG. 2, time t2 to time t4 in FIG. 8) and starter start is executed (step S60 in FIG. 2, time t1 to time t3 in FIG. 8), and it is determined that there is no assist margin. In this case (FIG. 2, step S50), the starter is started without shifting (step S80 in FIG. 2, time t2 in FIG. 9) (step S in FIG. 2). 0, it was adopted time t1~ time t3) configuration of FIG. 9.

  For example, even if the differential rotation is larger than a predetermined differential rotation, if the driver does not intend to accelerate, the engine and the motor generator are fastened on the high rotation side where the differential rotation is large without shifting.

  On the other hand, in the first embodiment, when engine start is requested during EV traveling, it is determined that the differential rotation is greater than the predetermined differential rotation, and even if it is determined that the driver does not intend to accelerate, the presence or absence of the assist margin is determined. Based on this, it is determined whether or not to execute the shift (FIG. 2, START → step S1 → step S10 → step S30 → step S40 → step S50 → step S60 or step S80 → END).

  As a result, when it is determined that the differential rotation is greater than the predetermined differential rotation with respect to the engine start request during EV traveling, and it is determined that the driver does not intend to accelerate, the shift is executed based on the presence or absence of the assist margin. By deciding whether or not to do so, deterioration of fuel consumption can be suppressed.

  In the first embodiment, the hybrid control module 81 (engine start control means, FIG. 2) causes the differential rotation to be equal to or less than a predetermined differential rotation when an engine start is requested during EV travel (FIG. 2, START → step S1 → step S10). When it is determined (step S30 in FIG. 2), it is determined whether or not there is a surplus torque that can be output by the motor / generator 4 (step 70 in FIG. 2). When it is determined that there is no margin torque (margin torque <predetermined margin torque), starter start is executed as engine start (FIG. 2, step 80), and margin torque is present (margin torque ≧ predetermined margin torque). When it is determined, a configuration is adopted in which a high-power start is executed as the engine start (FIG. 2, step 90).

  In general, the starter start generates more noise than the high power start.

On the other hand, in Example 1, when it is determined that the differential rotation is equal to or less than a predetermined differential rotation when an engine start request is made during EV traveling, if there is no surplus torque, starter start is executed as engine start ( FIG. 2, START → step S1 → step S10 → step S30 → step S70 → step S80 → END). For this reason, even when a strong electric start is not possible, the horizontally placed engine 2 can be reliably started.
Further, in the first embodiment, when it is determined that the differential rotation is equal to or less than the predetermined differential rotation at the time of the engine start request during EV traveling, when there is a surplus torque, the high-voltage start is executed as the engine start (FIG. 2). , START → step S1 → step S10 → step S30 → step S70 → step S90 → END). For this reason, generation | occurrence | production of noise can be suppressed. Therefore, when it is determined that the differential rotation is equal to or less than the predetermined differential rotation at the time of request for starting the engine during EV traveling, if there is a surplus torque, it is possible to obtain the quietness in the vehicle interior according to the passenger request.

  As a result, when it is determined that the differential rotation is equal to or less than the predetermined differential rotation when the engine is started during EV traveling, the lateral engine 2 can be started reliably when there is no margin torque, and there is margin torque. In such a case, it is possible to obtain the quietness in the passenger compartment according to the passenger request.

Next, the effect will be described.
In the control device for the FF plug-in hybrid vehicle of the first embodiment, the effects listed below can be obtained.

(1) The drive system includes an engine (horizontal engine 2) and a travel motor (motor / generator 4), and a clutch is provided between the engine (horizontal engine 2) and the travel motor (motor / generator 4). (First clutch 3) is interposed, and a transmission (belt type continuously variable transmission 6) is interposed between the driving motor (motor / generator 4) and the driving wheels (left and right front wheels 10R, 10L). In the hybrid vehicle control device, when there is an engine start request in an EV mode using the travel motor (motor / generator 4) as a drive source, engine start control means (hybrid) for starting the engine (horizontal engine 2) Control module 81, FIG. 2), high-power battery 21 that is a power source of the traveling motor (motor / generator 4), and the state of the high-power battery 21 Based on the above, after starting the engine (horizontal engine 2), it is determined whether there is an assist margin for torque assisting the engine (horizontal engine 2) by the driving motor (motor / generator 4). Means (hybrid control module 81, step S50 in FIG. 2), and the engine start control means (hybrid control module 81, FIG. 2) is provided when there is an engine start request during traveling in the EV mode (FIG. 2). START → step S1 → step S10) When it is determined that there is an assist margin (step S50 in FIG. 2), an upshift is executed and the engine is started (step S60 in FIG. 2).
For this reason, when it is determined that there is an assist margin for an engine start request during EV traveling, it is possible to suppress deterioration in fuel consumption after engine start.

(2) The engine start control means (hybrid control module 81, FIG. 2) includes a starter motor 1 in the drive system, and executes starter start using the starter motor 1 as the engine start (step S60 in FIG. 2). ).
For this reason, in addition to the effect of (1), the engine torque can be assisted by the motor torque for the assist margin when the engine is started during EV traveling.

(3) Differential rotation calculation means (hybrid control module 81; hybrid control module 81, which calculates differential rotation between the engine (horizontal engine 2) sandwiching the clutch (first clutch 3) and the travel motor (motor / generator 4) Step S30 in FIG. 2 is provided, and the engine start control means (hybrid control module 81, FIG. 2) is configured to request the engine start during running in the EV mode (START → step S1 → step S10 in FIG. 2), When it is determined that the differential rotation is greater than the predetermined differential rotation (step S30 in FIG. 2), when it is determined that there is no assist margin (step S50 in FIG. 2), the starter start is executed without shifting (FIG. 2). 2 step S80).
For this reason, in addition to the effect of (2), acceleration corresponding to the driver request can be obtained even when the assist by the motor torque cannot be expected for the engine start request during EV traveling.

(4) Acceleration intention determination means (hybrid control module 81, step S40 in FIG. 2) for determining whether or not the driver intends to accelerate is provided, and the engine start control means (hybrid control module 81, FIG. 2) is in the EV mode. When the engine start request during traveling (START → step S1 → step S10 in FIG. 2), it is determined that the differential rotation is greater than a predetermined differential rotation (step S30 in FIG. 2), and the driver does not intend to accelerate. When it is determined (step S40 in FIG. 2), when it is determined that there is an assist margin (step S50 in FIG. 2), an upshift is performed and the starter start is performed (step S60 in FIG. 2). If it is determined that there is no assist margin (step S50 in FIG. 2), the starter starts without shifting. To perform (step S80 in FIG. 2).
For this reason, in addition to the effect of (3), when it is determined that the differential rotation is greater than the predetermined differential rotation with respect to the engine start request during EV traveling, and it is determined that the driver does not intend to accelerate, the assist margin is reduced. By deciding whether or not to execute the shift based on the presence or absence, the deterioration of fuel consumption can be suppressed.

(5) The surplus torque that can be output from the travel motor (motor / generator 4) calculated from the upper limit torque that can be output from the travel motor (motor / generator 4) and the actual torque is less than the predetermined surplus torque. Surplus torque determining means (hybrid control module 81, step S70 in FIG. 2) is provided, and the engine start control means (hybrid control module 81, FIG. 2) is used to start the engine during traveling in the EV mode. When requested (START → step S1 → step S10 in FIG. 2), when it is determined that the differential rotation is equal to or less than the predetermined differential rotation (step S30 in FIG. 2), the margin torque is determined to be less than the predetermined margin torque. If this occurs (step S70 in FIG. 2), the starter start is executed as the engine start (step S in FIG. 2). 80) When it is determined that the margin torque is equal to or greater than the predetermined margin torque (step S70 in FIG. 2), a high-power start using the travel motor is executed as the engine start (step S90 in FIG. 2). .
For this reason, in addition to the effects of (3) to (4), when engine start is requested during EV travel, when it is determined that the differential rotation is less than the predetermined differential rotation, if there is no marginal torque, the horizontally placed engine 2 can be started, and when there is a surplus torque, it is possible to obtain the quietness of the passenger compartment according to the passenger request.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, the capacitor 23 is used as the power source for the starter motor 1. However, the configuration is not limited to that shown in the first embodiment. For example, a 12V battery 22 may be used as the power source for the starter motor 1.

  In the first embodiment, the belt-type continuously variable transmission 6 which is a continuously variable transmission CVT is shown as the transmission. However, the configuration is not limited to that shown in the first embodiment. For example, the belt type continuously variable transmission 6 may be another continuously variable transmission CVT, or the continuously variable transmission CVT may be an automatic transmission AT or MT transmission.

  In the first embodiment, whether the driver intends to accelerate or not is determined based on the accelerator opening (FIG. 3, step S21), the depression speed (FIG. 3, step S22), and the accelerator opening change (FIG. 3, step S23). showed that. However, the configuration is not limited to that shown in the first embodiment. For example, in the rapid acceleration determination in step S20 of FIG. 3, the presence or absence of the intention of acceleration is determined from at least one of the depression speed (FIG. 3, step S22) and the accelerator opening change amount (FIG. 3, step S23). May be. In short, in the rapid acceleration determination in step S20 of FIG. 2, it is only necessary to determine whether or not the driver intends to accelerate based on at least the driver's accelerator depression operation speed. Further, in the rapid acceleration determination of step S40 in FIG. 3, among the accelerator opening (FIG. 3, step S41), the depression speed (FIG. 3, step S42) and the accelerator opening change amount (FIG. 3, step S43), 1 Whether or not the driver intends to accelerate may be determined based on one or more. In short, it is only necessary to determine whether or not the driver intends to accelerate.

  In the first embodiment, after the horizontal engine 2 is started, it is determined whether there is an assist margin for torque assisting the horizontal engine 2 by the motor / generator 4 (after-start assist margin determination, step S50, FIG. 2 and FIG. 4). In the example shown in FIG. However, the configuration is not limited to that shown in the first embodiment. For example, the presence or absence of an assist margin may be determined from one or more of the three steps.

In the first embodiment, as an example of executing the starter start as the engine start, in the flowchart of FIG. 2, the flow proceeds from START → step S1 → step S10 → step S30 → (step S40 →) step S60 → END, START → Step S1-> Step S10-> Step S30-> Step S40-> Step S60-> End END, START-> Step S1-> Step S10-> Step S30-> Step S40-> Step S50-> Step S60-> End END . However, in these cases, the present invention is not limited to a configuration that performs starter start as engine start. That is, a high power start may be executed as the engine start.
However, even if the high-power start is executed, the high-power start can be executed only when the conditions set in each step S are satisfied (except for the starter start conditions). For example, in the flowchart of FIG. 2, the flow that proceeds from START → step S1 → step S10 → step S30 → step S40 → step S50 → step S60 → END is set to step S50 even if the high power start is executed. If the condition is satisfied, a strong electric start may be performed.

  In Example 1, the example which applies the control apparatus of this invention to FF plug-in hybrid vehicle was shown. However, the configuration is not limited to that shown in the first embodiment. For example, the present invention may be applied to an FR plug-in hybrid vehicle or a 4WD plug-in hybrid vehicle. Further, the control device of the present invention can be applied not only to plug-in hybrid vehicles but also to FR hybrid vehicles, FF hybrid vehicles, and the like.

1 Starter motor 2 Horizontal engine (engine)
3 First clutch (clutch)
4 Motor / generator 5 Second clutch 6 Belt type continuously variable transmission (transmission)
10R, 10L Left and right front wheels (drive wheels)
11R, 11L Left and right rear wheels 14 Main oil pump (oil pump)
21 High-power battery 23 Capacitor 81 Hybrid control module (engine start control means)

Claims (5)

A hybrid vehicle control device comprising an engine and a travel motor in a drive system, a clutch interposed between the engine and the travel motor, and a transmission interposed between the travel motor and a drive wheel In
When there is an engine start request in EV mode using the traveling motor as a drive source, engine start control means for starting the engine,
Differential rotation calculation means for calculating a differential rotation between the engine and the traveling motor with the clutch interposed therebetween;
A high-power battery that is a power source of the traveling motor;
After starting the engine, based on the state of the high-power battery, provided a start margin assist margin determining means for determining the presence or absence of an assist margin for torque assisting the engine by the travel motor,
The engine start control means performs an upshift when it is determined that there is an assist margin when it is determined that the differential rotation is greater than a predetermined differential rotation when an engine start request is made during traveling in the EV mode. A control apparatus for a hybrid vehicle, characterized by executing engine start. In the hybrid vehicle control device according to claim 1,
The drive system is equipped with a starter motor,
The engine start control means executes a starter start using the starter motor as the engine start. In the hybrid vehicle control device according to claim 2,
Before SL engine start control means, the time of engine start request during traveling by the EV mode, when the differential speed is determined to be greater than a predetermined differential rotation, when it is determined that no assist margin, said without shifting A control apparatus for a hybrid vehicle, characterized by executing starter start. In the hybrid vehicle control device according to claim 3,
Acceleration intention determination means is provided for determining whether the driver intends to accelerate,
The engine start control means has the assist margin when it is determined that the differential rotation is larger than a predetermined differential rotation and the driver does not intend to accelerate when the engine start request during traveling in the EV mode is requested. When it is determined that the starter is started, the starter is started, and when it is determined that there is no assist margin, the starter is started without shifting. apparatus. In the hybrid vehicle control device according to claim 3 or 4,
Provided is a surplus torque determination means for determining whether or not a surplus torque that can be output by the travel motor calculated from an upper limit torque and an actual torque that can be output by the travel motor is less than a predetermined surplus torque;
The engine start control means, when the engine start request during running in the EV mode, when the differential rotation is determined to be less than or equal to a predetermined differential rotation, and when the margin torque is determined to be less than the predetermined margin torque Performs the starter start as the engine start, and executes a high-power start using the traveling motor as the engine start when it is determined that the margin torque is equal to or greater than the predetermined margin torque. Control device for hybrid vehicle.