JP4254277B2 - Vehicle lock-up clutch control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control device provided with a fuel supply amount suppression means for suppressing fuel supply to an engine when the engine rotation speed is in a fuel reduction region based on a preset engine rotation speed during vehicle deceleration. In particular, the engagement state is switched in the direction in which the engagement force of the lockup clutch is increased in order to perform more suppression operation of the fuel supply to the engine by the fuel supply amount suppression means. The present invention relates to a lock-up clutch control technique for further improving fuel efficiency when the fuel reduction region is changed in a vehicle.
[0002]
[Prior art]
2. Description of the Related Art There is known a vehicle provided with a fuel supply amount suppressing device that suppresses the amount of fuel supplied to an engine, for example, a fuel cut, for the purpose of improving fuel efficiency while the vehicle is decelerating. For example, as shown in Patent Document 1, a region where fuel cut to the engine during deceleration traveling is performed at a predetermined engine rotational speed, for example, a fuel cut start rotational speed and a fuel cut return rotational speed (fuel supply return determination for stopping fuel cut) In order to improve the fuel efficiency when the accelerator is turned off, the engine rotation speed is set to the fuel cut start rotation to increase the period during which the engine rotation speed is equal to or higher than the fuel cut return rotation speed. When the speed is lower than the speed, the engagement force of the lockup clutch is positively increased so that the fuel cut to the engine is executed, that is, the engine speed is increased to the area higher than the fuel cut start speed. Technology to switch the engagement state in the direction It has been proposed. In addition, in order for the engine to be maintained at a stable and smooth rotational speed at the time of restart, a certain margin is required for the engine rotational speed when the fuel supply is resumed with respect to the idle rotational speed. Since the return rotational speed is set so as to have the margin, for example, as shown in Patent Document 2, when the rotational drive of the engine at the time of restart can be assisted by a rotational drive device such as an electric motor, the fuel cut is performed. A technique has been proposed in which the region is changed to a lower rotational speed side to improve fuel consumption.
[0003]
[Patent Document 1]
JP 11-257484 A
[Patent Document 2]
JP 2001-82204 A
[Patent Document 3]
JP 63-203439 A
[Patent Document 4]
JP 2001-99308 A
[Patent Document 5]
JP 2001-146926 A
[0004]
[Problems to be solved by the invention]
However, a lockup clutch that is executed based on a preset lockup operating point even if the region in which the fuel cut to the engine is executed is changed to a lower engine speed for the purpose of improving fuel efficiency. Depending on the engagement state of the engine, the engine rotation speed is changed from the engagement state to the lockup off state in the direction in which the engagement force of the lockup clutch is increased even in the region where the fuel cut can be performed. The reduction of the fuel consumption was accelerated, and the fuel supply speed was reduced to the fuel cut return speed or less, and the fuel supply to the engine was resumed. This could suppress the improvement in fuel efficiency and deteriorate the drivability due to the deceleration shock. In addition, the fuel supply amount to the engine is controlled to be reduced based on the engine speed when the accelerator or the throttle is fully closed while the vehicle is decelerating instead of the fuel cut region for executing fuel cut for the purpose of improving fuel efficiency. There are vehicles set in advance. Even if the setting is changed so that the fuel supply amount is further reduced in such a vehicle, the improvement in fuel consumption is suppressed or the deceleration shock is affected depending on the engagement state of the lockup clutch, as in the change of the fuel cut region. There was a possibility that the drivability by would deteriorate.
[0005]
The present invention has been made in the background of the above circumstances, and its purpose is to provide an engine that operates by combustion of fuel, a fluid transmission device with a lock-up clutch, and an accelerator or When the throttle is determined to be fully closed, a vehicle having a fuel supply amount suppression means for suppressing fuel supply to the engine when the engine rotation speed is in a fuel reduction region based on a preset engine rotation speed In the control device, in particular, when the fuel reduction region is changed in order to extend the fuel supply amount suppression period for the purpose of improving fuel efficiency, the lockup clutch is engaged according to the changed fuel reduction region. To provide a vehicle lock-up clutch control device that further improves fuel efficiency and improves drivability. Located in.
[0006]
[Means for Solving the Problems]
  To achieve this object, the gist of the present invention is that: (a) an engine that operates by combustion of fuel, a rotary drive device that is operatively connected to the engine, a fluid transmission device with a lock-up clutch, (B) When it is determined that the accelerator or the throttle is fully closed during the vehicle decelerating, the vehicle is based on the relationship between the fuel supply amount and the preset engine rotation speed. A fuel supply amount suppressing means for suppressing fuel supply to the engine, (c) a fuel supply set amount changing means for changing the relationship of the fuel supply amount to the engine speed, and (d) a preset lockup Lockup clutch control means for switching the engagement state of the lockup clutch based on an operating point; and (e) the fuel supply set amount changing means by the fuel supply set amount changing means. Lock-up operating point changing means for changing the lock-up operating point when the accelerator or throttle is determined to be fully closed in accordance with the change in the relationship of the fuel supply amount to the engine rotational speed, and (f) the rotation drive device Drive assist means for operating and assisting the engine rotational speed, and (g) determining whether or not the drive assist means determines whether or not the rotational speed of the engine can be assisted by operating the rotational drive device. And (h) the relationship of the fuel supply amount with respect to the engine rotation speed is determined by the fuel supply amount with respect to the engine rotation speed for causing the fuel supply amount suppression means to reduce and control the fuel supply to the engine.In addition, the two-dimensional coordinates of the line indicating the engine rotation speed and the line indicating the fuel supply amount indicate a predetermined fuel supply restart rotation speed on the line indicating the engine rotation speed, so that the predetermined engine speed decreases as the engine rotation speed decreases. Increase towards the point indicating fuel supply(I) the lockup operating point changing means is configured to determine whether the accelerator or the throttle is fully closed according to the change of the fuel reduction line by the fuel supply set amount changing means. The lock-up operating point is changed, and (j) a plurality of the fuel reduction lines are set so as to be changeable by the fuel supply set amount changing means, and (k) the fuel supply set amount changing means is When it is determined by the drive assist enable / disable determining means that the rotation speed of the engine can be assisted by the operation of the rotary drive device, the fuel supply amount to the engine is reduced compared to the case where it is not determined. To select a fuel reduction lineThe (l)The lockup operating point changing means changes the lockup operating point to a low vehicle speed side when the fuel supply set amount changing means changes the fuel reduction line to a side where the fuel supply amount with respect to the engine rotation speed is reduced. Is what(m) The fuel supply set amount changing means determines the relationship between the engine rotation speed and the fuel supply amount when the rotation speed is equal to or less than the fuel supply restart rotation speed when the drive assist availability determination means determines that the engine rotation speed can be assisted. Compared to the fuel reduction line used when not determined to be possible,The point indicating the predetermined fuel supply restarting rotational speed, which is one end of the fuel reduction line, is changed in the engine rotational speed decreasing direction.There is.
[0007]
【The invention's effect】
  In this way, when it is determined that the accelerator or throttle is fully closed while the vehicle is decelerating, a preset engine speed is set so that fuel supply to the engine is suppressed by the fuel supply amount suppression means. When the relationship between the fuel supply amount and the speed is changed by the fuel supply set amount changing means, a preset lockup operating point for executing switching of the engagement state of the lockup clutch by the lockup clutch control means is set. Since the lockup operation point changing means changes according to the change in the relationship of the fuel supply amount with respect to the engine rotation speed, the lock by the change in the relationship of the fuel supply amount with respect to the engine rotation speed and the change of the lockup operation point The timing of switching the engagement state of the up clutch is matched, for example, the lock Since Pukuratchi switching of engagement in the direction of increasing the engagement force is executed, the deceleration shock can be reduced driveability is improved. Further, for example, when it is determined by the drive assist enable / disable determining means that the rotation speed of the engine can be assisted by the operation of the rotation drive device, the relationship between the fuel supply amount and the engine rotation speed indicates that the engine rotation speed is low. When the speed is changed to the rotational speed side, the lock-up operating point is also changed to the low vehicle speed side, that is, the low rotational speed side corresponding to the vehicle speed during deceleration. This improves fuel economy. In addition, the relationship of the fuel supply amount with respect to the engine rotation speed is such that the fuel supply amount with respect to the engine rotation speed for causing the fuel supply amount suppression means to reduce and control the fuel supply to the engine.In addition, the two-dimensional coordinates of the line indicating the engine rotation speed and the line indicating the fuel supply amount indicate a predetermined fuel supply restart rotation speed on the line indicating the engine rotation speed, so that the predetermined engine speed decreases as the engine rotation speed decreases. Increase towards the point indicating fuel supplyThe lockup operating point changing means is a preset fuel reduction line, and the lockup operating point changing means is the lockup when the accelerator or the throttle is determined to be fully closed according to the change of the fuel reduction line by the fuel supply set amount changing means. A plurality of the fuel reduction lines are set so as to be changeable by the fuel supply set amount changing means, so that the drive assist enable / disable judging means operates the rotary drive device to operate the engine. When it is determined that the rotation speed can be assisted, a fuel supply amount with respect to the engine rotation speed is set in advance so as to reduce the fuel supply to the engine by the fuel supply amount suppression unit as compared with the case where it is not determined. When the fuel reduction line is changed to the low speed side by the fuel supply set amount changing means, the lockup clutch control means Since the preset lock-up operating point for switching the engagement state of the lock-up clutch is changed by the lock-up operating point changing means according to the change of the fuel reduction line, the fuel reduction The timing of switching the engagement state of the lockup clutch by the change of the line and the change of the lockup operation point is matched, and drivability is improved.Also,The lockup operating point changing means changes the lockup operating point to a low vehicle speed side when the fuel supply set amount changing means changes the fuel reduction line to a side where the fuel supply amount with respect to the engine rotation speed is reduced. The fuel supply set amount changing means can assist the rotation speed of the engine by the drive assist enable / disable judging means based on the relationship between the engine rotation speed and the fuel supply amount when the rotation speed is less than the fuel supply restart rotation speed. If determined, compared to the fuel reduction line used when not determined to be possible,The point indicating the predetermined fuel supply restarting rotational speed, which is one end of the fuel reduction line, is changed in the engine rotational speed decreasing direction.Therefore, it is determined by the drive assist enable / disable determining means whether or not the rotation speed of the engine can be assisted by the operation of the rotational drive device by the drive assist means, and the fuel reduction line is set according to the determination result by the fuel supply set amount changing means. Thus, for example, when the engine speed can be assisted by the rotary drive device, the fuel reduction line is preferably changed to the low engine speed side, that is, the side where the fuel supply amount is reduced.
[0008]
Other aspects of the invention
Here, preferably, (a) the relationship of the fuel supply amount with respect to the engine rotational speed is such that when the engine rotational speed is higher than a predetermined return rotational speed, the fuel supply amount suppression means causes the fuel to be supplied to the engine. (B) The lockup operating point changing means is configured to fully close an accelerator or a throttle according to a change in the fuel cut area by the fuel supply set amount changing means. The lock-up operating point when it is determined that is changed. In this manner, when the fuel cut region for stopping the fuel supply to the engine by the fuel supply amount suppressing means is changed by the fuel supply set amount changing means, the lockup clutch control means engages the lockup clutch. Since the preset lock-up operating point for switching the state is changed by the lock-up operating point changing means according to the change of the fuel cut region, the change of the fuel cut region and the lock up thereof are performed. The timing of switching the engagement state of the lockup clutch by changing the operating point is matched and drivability is improved. For example, when the engine speed is changed to the low speed side in the fuel cut region, the lockup operating point is also changed to the low speed side corresponding to the low vehicle speed side, that is, the vehicle speed during deceleration. Therefore, the stop time of fuel supply to the engine becomes longer and fuel consumption improves.
[0009]
Preferably, (a) a rotational drive device operatively connected to the engine, drive assist means for operating the rotational drive device to assist the engine rotational speed, and the rotation by the drive assist means. Drive assist enable / disable determining means for determining whether or not the rotational speed of the engine can be assisted by operating the drive device, and (b) the fuel supply set amount changing means is determined by the drive assist enable / disable determining means The fuel cut area is changed according to the result. In this way, it is determined by the drive assist enable / disable determining means whether or not the rotation speed of the engine can be assisted by the operation of the rotational drive device by the drive assist means, and the fuel supply set amount changing means according to the determination result. Since the fuel cut region is changed, for example, when the engine speed can be assisted by the rotation drive device, the fuel cut region is suitably changed to the low engine speed side.
[0010]
Preferably, the lock-up operating point changing means increases the lock-up operating point when the fuel cut region is changed to a high rotational speed side of the engine rotational speed by the fuel supply set amount changing means. The speed is changed to the vehicle speed side. In this way, the timing of switching the engagement state of the lockup clutch is matched and drivability is improved.
[0011]
Preferably, the lock-up clutch control means assists the engine rotational speed by the drive assist means by the drive assist availability determination means while the fuel supply amount suppression means stops the fuel supply to the engine. If it is determined that the fuel supply amount is not possible, the lockup clutch is not locked up until the fuel supply to the engine is stopped by the fuel supply amount suppression means and the fuel supply is resumed. . In this way, the possibility that the lockup is turned off before the fuel supply to the engine is resumed and the engine rotation speed is reduced and the engine is not restarted is solved.
[0012]
Preferably, (a) the relationship of the fuel supply amount with respect to the engine rotation speed is determined in advance by the fuel supply amount with respect to the engine rotation speed for reducing control of fuel supply to the engine by the fuel supply amount suppression means. (B) the lockup operation point changing means is the fuel reduction set line when the accelerator or the throttle is determined to be fully closed according to the change of the fuel reduction line by the fuel supply set amount changing means. The lock-up operating point is changed. In this manner, when the fuel reduction line in which the fuel supply amount with respect to the engine speed for reducing the fuel supply to the engine is controlled by the fuel supply amount suppression unit is changed by the fuel supply set amount changing unit, A preset lock-up operating point for switching the engagement state of the lock-up clutch by the lock-up clutch control means is changed by the lock-up operating point changing means according to the change of the fuel reduction line. Therefore, the timing of switching the engagement state of the lockup clutch by the change of the fuel reduction line and the change of the lockup operation point is matched, and drivability is improved. Further, for example, when the fuel reduction line is changed to the low engine speed side, that is, the side where the fuel supply amount is reduced, the lock-up operating point also corresponds to the low vehicle speed side, that is, the vehicle speed during deceleration. Since the engine speed is changed to the lower rotation speed side, the fuel supply time to the engine is reduced and the fuel consumption is improved.
[0015]
Preferably, the lock-up clutch control means controls the engine rotation speed by the drive assist means by the drive assist availability determination means during the fuel supply reduction control by the fuel supply amount suppression means. When it is determined that assistance is not possible, the lockup clutch is not locked up until the fuel supply reduction control by the fuel supply amount suppression means is stopped and fuel supply is resumed. It is. In this way, the possibility that the lockup is turned off before the fuel supply to the engine is resumed and the engine rotation speed is reduced and the engine is not restarted is solved.
[0016]
Preferably, (a) a shift control means for performing a downshift of the automatic transmission based on a preset downshift point, and a downshift point changing means for changing the downshift point, (b) The downshift point changing means changes the downshift point in accordance with the change of the lockup operating point by the lockup operating point changing means. In this way, the downshift of the automatic transmission is executed by the shift control means based on the downshift point changed by the downshift point changing means in accordance with the change of the lockup action point by the lockup action point changing means. Therefore, for example, when the lockup operation point is changed to the low vehicle speed side, that is, the side where the engagement state in the direction of increasing the engagement force of the lockup clutch is continued longer by the lockup operation point changing means, A downshift is executed to increase the engine speed so that the engagement state in the direction in which the engagement force is increased is continued. As a result, the fuel supply suppression time to the engine becomes longer and fuel consumption improves.
[0017]
Preferably, the downshift point changing means changes the downshift point only when the fuel supply amount suppressing means can suppress the fuel supply to the engine. In this way, when the fuel supply to the engine can be suppressed by the fuel supply amount suppression means, the downshift point is changed by the downshift point changing means so that the suppression of the fuel supply is made longer. When the fuel supply cannot be suppressed, the downshift point is not changed. For example, the downshift point is changed according to the lockup operation point set at the high vehicle speed side and As a result of downshifting being performed, it is possible to avoid a possibility of a greater shift shock compared to downshifting at a low engine speed, thereby improving drivability.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
[0019]
FIG. 1 is a skeleton diagram illustrating the configuration of a power transmission device 8 for a hybrid vehicle to which the present invention is applied. In FIG. 1, for example, an output of an engine 10 as a driving force source for driving constituted by an internal combustion engine is input to an automatic transmission 16 via an input clutch 12 and a torque converter 14 as a fluid transmission device, and is not shown. It is transmitted to the drive wheel via the differential gear device and the axle. Between the input clutch 12 and the torque converter 14, an electric motor as a rotating machine and a first motor generator MG1 functioning as a generator are disposed. The torque converter 14 includes a pump impeller 20 connected to the input clutch 12, a turbine impeller 24 connected to the input shaft 22 of the automatic transmission 16, and a space between the pump impeller 20 and the turbine impeller 24. A lockup clutch 26 for direct connection and a stator impeller 30 that is prevented from rotating in one direction by a one-way clutch 28 are provided. The lock-up clutch 26 is a hydraulic friction clutch that is frictionally engaged by a differential pressure ΔP between the hydraulic pressure in the engagement-side oil chamber 25 and the hydraulic pressure in the release-side oil chamber 27, and is fully engaged. As a result, the pump impeller 20 and the turbine impeller 24 are rotated together. Further, the differential pressure ΔP, that is, the engagement torque is feedback-controlled so as to be engaged in a predetermined slip state, so that the turbine impeller 24 is driven at a predetermined target slip amount of, for example, about 50 rpm when the vehicle is driven (power-on). While the pump impeller 20 is rotated following, the pump impeller 20 is rotated following the turbine impeller 24 with a predetermined target slip amount of, for example, about −50 rpm when the vehicle is not driven (power off).
[0020]
The automatic transmission 16 includes a first transmission unit 32 that switches between two stages of high and low, and a second transmission unit 34 that can switch between a reverse transmission stage and four forward stages. The first transmission unit 32 is supported by the sun gear S0, the ring gear R0, and the carrier K0 so as to be rotatable, and the planetary gear P0 includes a planetary gear P0 meshed with the sun gear S0 and the ring gear R0, and the sun gear S0 and the carrier. A clutch C0 and a one-way clutch F0 provided between K0 and a brake B0 provided between the sun gear S0 and the housing 38 are provided.
[0021]
The second transmission unit 34 is supported by the sun gear S1, the ring gear R1, and the carrier K1 so as to be rotatable, and the first planetary gear device 40 including the planetary gear P1 meshed with the sun gear S1 and the ring gear R1, and the sun gear S2, A second planetary gear unit 42 including a planetary gear P2 that is rotatably supported by the ring gear R2 and the carrier K2 and meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3 is rotatable. And a third planetary gear unit 44 comprising a planetary gear P3 supported and meshed with the sun gear S3 and the ring gear R3.
[0022]
The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2, and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 46. Further, the ring gear R2 is integrally connected to the sun gear S3 and the intermediate shaft 48. A clutch C1 is provided between the ring gear R0 and the intermediate shaft 48, and a clutch C2 is provided between the sun gear S1, the sun gear S2, and the ring gear R0. The housing 38 is provided with a band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2. A one-way clutch F1 and a brake B2 are provided in series between the sun gear S1 and sun gear S2 and the housing 38. The one-way clutch F <b> 1 is configured to be engaged when the sun gear S <b> 1 and the sun gear S <b> 2 try to reversely rotate in the direction opposite to the input shaft 22.
[0023]
A brake B3 is provided between the carrier K1 and the housing 38, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 38. The one-way clutch F2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction.
[0024]
In the automatic transmission 16 configured as described above, for example, in accordance with the operation table shown in FIG. 2, the reverse speed and the gear ratio γ (the rotational speed N of the input shaft 22)._IN/ Rotation speed N of output shaft 46_OUT) Is gradually changed to any one of the five forward speeds (1st to 5th). In FIG. 2, “◯” indicates engagement, a blank indicates release, “◎” indicates engagement during engine brake or driving force source braking by regenerative braking of the first motor generator MG1, and “Δ” indicates power transmission. Represents an engagement that is not involved. The clutches C0 to C2 and the brakes B0 to B4 are all hydraulic friction engagement devices that are engaged by a hydraulic actuator. As is apparent from FIG. 2, the so-called second gear stage and the third gear stage are achieved by releasing one of the brake B2 and the brake B3 and simultaneously engaging the other. This is a clutch-to-clutch shift.
[0025]
FIG. 3 schematically shows a configuration of the power transmission device of the hybrid vehicle shown in FIG. As shown in FIG. 3, an exhaust turbine supercharger 54 is provided in the intake pipe 50 and the exhaust pipe 52 of the engine 10, and a bypass passage 58 having a waste gate valve 56 is provided in the exhaust pipe 52. The supercharging pressure in the intake pipe 50 can be adjusted by changing the turbine rotation by controlling the flow rate of the exhaust gas flowing through the bypass passage 58 provided in parallel. The intake pipe 50 is provided with an electronic throttle valve 62 that is controlled to open and close by a throttle actuator 60. As shown in FIG. 7, the electronic throttle valve 62 basically has an accelerator opening A representing the driver's required output amount._CCOpening angle corresponding to_THIt is controlled to become.
[0026]
Further, in the engine 10, as shown in FIG. 4, an intake valve 74 and an exhaust valve 75 provided in each cylinder have an opening / closing timing, an opening / closing period, a lift amount, etc. in accordance with a command from an electronic control unit to be described later. It is composed of an electrically controlled open / close control valve, that is, an electromagnetically driven valve. The engine 10 includes a variable valve mechanism 78 that includes an intake valve 74 and an exhaust valve 75 and electromagnetic actuators 76 and 77 that are electric actuators for opening and closing them, and a crankshaft rotation that detects the rotation angle of the crankshaft 79. A valve drive control device 81 that controls the opening / closing timing, lift amount, and operating angle (opening / closing speed) of the intake valve 74 and the exhaust valve 75 in accordance with a signal from the angle sensor 80 is provided. The valve drive control device 81 not only changes the opening / closing timing and the like to the optimal timing according to the engine load, but also includes a timing for operating the engine 10 in four cycles and a timing for operating in two cycles according to the operation cycle switching command. Control to be. Further, by changing the operation timing of the intake valve 74 and the exhaust valve 75 or changing the number of operating cylinders, the engine itself can rotate the engine speed N._EFor example, by opening and closing the exhaust valve 75 according to normal control while the intake valve 74 is closed, the rotation of the engine is generated by generating rotational resistance by the compression work of the piston and consuming rotational energy. Speed N_ECan be forcibly and rapidly reduced, and the opening of the intake valve 74 is controlled so that the engine speed N_EThe rate of change can be adjusted. For example, as shown in FIG. 5, the electromagnetic actuators 76 and 77 are connected to an intake valve 74 or an exhaust valve 75 and are made of a magnetic material supported so as to be movable in the axial direction of the intake valve 74 or the exhaust valve 75. A disk-shaped movable member 82, a pair of electromagnets 84 and 85 provided at positions sandwiching the movable member 82 to selectively attract the movable member 82, and the movable member 82 are urged toward the neutral position. A pair of springs 86 and 87 are provided. The intake valve 74 and the exhaust valve 75 correspond to an electrically operated on / off valve that can be electrically opened and closed.
[0027]
The first motor generator MG1 is disposed between the engine 10 and the automatic transmission 16 so as to be operatively connected to the engine 10, and the input clutch 12 is disposed between the engine 10 and the first motor generator MG1. Has been. The hydraulic friction engagement devices and the lock-up clutch 26 of the automatic transmission 16 are mechanically connected to the engine 10 via the electric hydraulic pump 64 or the drive switching oil pump clutch 69 and are directly driven to rotate thereby. The hydraulic pressure is controlled by a hydraulic control circuit 66 that uses the hydraulic pressure generated from the mechanical oil pump 68 as a source pressure. The original pressure, that is, the line pressure is a maximum engagement pressure used for engaging each hydraulic friction engagement device of the automatic transmission 16. The engine 10 is operatively connected to a second motor generator MG2 that functions as an electric motor or a generator as a rotating machine. Further, the first motor generator MG1 and the second motor generator MG2 also function as a rotation drive device that assists the rotation of the engine 10 by its operation. Then, the fuel cell 70 and the secondary battery 71 functioning as a power source for the first motor generator MG1 and the second motor generator MG2, and the current supplied from them to the first motor generator MG1 and the second motor generator MG2 are controlled. Or power supply changeover switches 72 and 73 for controlling the current supplied to the secondary battery 71 for charging. The power supply changeover switches 72 and 73 indicate devices having a switching function, and may be constituted by, for example, a semiconductor switching element having an inverter function or the like.
[0028]
FIG. 6 is a block diagram illustrating a control system for the power transmission device 8 of the present embodiment. In FIG. 6, signals input to the electronic control device 90 and signals output from the electronic control device 90 are illustrated. For example, the electronic control unit 90 includes an accelerator opening A that is an operation amount of an accelerator pedal detected by an accelerator opening sensor._CC, An opening degree signal of the throttle valve 62 detected by the throttle opening degree sensor._TH, A throttle opening signal indicating the rotation speed N of the output shaft 46 detected by the output shaft rotation speed sensor 47_OUTThat is, the vehicle speed signal corresponding to the vehicle speed V, the turbine rotational speed N detected by the turbine rotational speed sensor 91._T(= Rotational speed N of the input shaft 22_IN), The engine speed N detected by the engine speed sensor_E, A supercharging pressure P in the intake pipe 50_a, A signal representing the air-fuel ratio A / F, the operation position P of the shift lever 92_SH, A hydraulic oil temperature of the transmission 16, that is, an AT oil temperature T_OILEtc. are supplied from a sensor (not shown). Further, from the electronic control unit 90, the accelerator opening A_CCThrottle opening θ_THA signal for driving the throttle actuator 60 for controlling the injection, an injection signal for controlling the amount of fuel injected into the cylinder of the engine 10 from the fuel injection valve, and a hydraulic control circuit for switching the gear stage of the automatic transmission 16 Linear solenoid valve for controlling signals S1, S2, S3 for controlling the shift solenoid for driving the shift valve in 66, engagement / release of lockup clutch 26, slip amount, direct control of brake B3, and clutch-to-clutch shift. Command signal D for driving SLU_SLU, The opening θ of the throttle valve 62_THThrottle pressure P with a size corresponding to_THCommand signal D for driving linear solenoid valve SLT that generates_SLT, Command value signal D for driving linear solenoid valve SLN for controlling accum back pressure_SLNAre output respectively.
[0029]
The electronic control unit 90 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. By performing, for example, the accelerator opening A corresponding to the actual accelerator pedal operation amount from the previously stored relationship shown in FIG._CC(%) Based on throttle opening θ_TH(%) Throttle opening control, shift control for automatically switching the gear stage of the automatic transmission 16, lockup clutch control for engaging, releasing or slipping the lockup clutch 26, supercharging pressure control Air-fuel ratio control, cylinder selection switching control, operation cycle switching control, and the like are executed. For example, in the shift control described above, for example, the actual accelerator opening A can be calculated from the pre-stored relationship shown in FIG._CC(%) Or throttle opening θ_TH(%) And the vehicle speed V (km / h), the gear position of the automatic transmission 16 is determined, and the solenoid valve S1 of the hydraulic control circuit 66 so as to obtain the determined gear position and engagement state, When S2 and S3 are driven to generate engine braking, the solenoid valve S4 is driven. The shift line in the shift diagram of FIG. 8 indicates the actual accelerator opening A._CC(%) Or throttle opening θ_THWhether the actual vehicle speed V crosses the line on the horizontal line indicating (%), that is, the value (shift speed vehicle speed) V at which a shift on the shift line is to be executed_SFor determining whether or not the value V is exceeded._SThat is, it is stored in advance as a series of shift point vehicle speeds. In the process of this shift control, the input torque T of the automatic transmission 16_INThe input pressure T of the engagement pressure of the hydraulic friction engagement device involved in the shift or the line pressure that is the source pressure thereof is calculated._INThe size is controlled according to.
[0030]
Further, in the lockup clutch control, in order to reduce the rotation loss of the torque converter 14 and the like during acceleration traveling, for example, a vehicle speed V representing an actual vehicle traveling state from a lockup area diagram stored in advance as shown in FIG. (Output side rotation speed N_OUTAccelerator opening A indicating the driver's required output amount_CCOr throttle opening θ_THBased on (%), it is determined whether the region belongs to the engagement region, the release region, or the slip region, and the lock-up control solenoid in the hydraulic control circuit 66 is operated so as to operate the determined region. To control the lock-up clutch 26 to be engaged, released, or slipped. The lockup region line in the lockup region diagram of FIG. 9 indicates the actual accelerator opening A._CC(%) Or throttle opening θ_THIt is determined whether or not the actual vehicle speed V crosses the horizontal line indicating (%), that is, whether or not the value for executing the switching of the lock-up clutch operation of the lock-up region line has been exceeded, that is, whether or not the lock-up operating point has been exceeded. Therefore, it is also stored in advance as a series of the lock-up operating points. In the slip region, in order to suppress the power transmission loss of the torque converter 14 as much as possible while absorbing the rotational fluctuation of the engine 10 for the purpose of improving the fuel efficiency as much as possible without impairing drivability. Then, slip control of the lockup clutch 26 is executed. For slip control of the lockup clutch 26, the turbine rotational speed N_TAnd engine speed N_ERotational speed difference (slip amount) N_SLP(= N_E-N_T) Is the target rotational speed difference (target slip amount) N_SLP ^*To control the differential pressure ΔP of the lock-up clutch 26 to control the drive signal S for the solenoid valve SLU._SLUIs output. Of the slip control, slip control during deceleration traveling is performed by, for example, throttle valve opening θ_THIs at a gear stage that transmits the reverse input from the drive wheel side to the engine 10 side, that is, at a gear speed that provides an engine braking action, and is generated at the time of forward running in which the vehicle runs inertially (decelerated)._TAnd engine speed N_EIs the drive signal S for the solenoid valve SLU_SLURotational speed difference N by feedback control using_SLPIs the target rotational speed difference N_SLP ^*For example, in the state of -50 to -100 rpm, the speed is gradually decreased as the vehicle decelerates. When the lockup clutch 26 is slip-engaged in this way, the engine speed N_EIs the turbine speed N_TSince the engine is pulled up to the vicinity, the control state for suppressing the amount of fuel supplied to the engine 10 is maintained for a longer period, and the fuel consumption is improved.
[0031]
In FIG. 10, the shift operation device 94 including the shift lever 92 is disposed beside the driver's seat, for example, and the shift lever 92 is a parking position P for locking the output shaft 46 of the automatic transmission 16. The reverse travel position R for reverse travel, the neutral position N where the power transmission path in the automatic transmission 16 is cut off, and the range from the first gear to the fifth gear in the automatic gear shift mode. A forward traveling position D (maximum speed range position) that is automatically shifted, a fourth engine brake traveling position 4 that is automatically shifted in the range from the first gear to the fourth gear and is operated with an engine brake at each gear. , A third engine brake travel position 3 in which automatic transmission is performed in the range from the first speed gear stage to the third speed gear stage and the engine brake is applied at each gear stage, and the range from the first speed gear stage to the second speed gear stage. Operation is possible to a second engine brake travel position 2 where the gear is automatically shifted and the engine brake is applied at each gear stage, and to a first engine brake travel position L where the engine brake is applied and the engine brake is applied. Is provided. The shift operation device 94 is provided with a switch (not shown) for detecting each operation position of the shift lever 92, and the operation position P of the shift lever 92 is provided._SHIs output to the electronic control unit 90. The shift operation device 94 is provided with a mode switch 96 for switching to a manual transmission mode for sports driving or the like. When the manual shift mode is selected by the mode change switch 96, a manual shift operation button provided on a steering wheel (not shown) is validated.
[0032]
FIG. 11 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 90. In the figure, an accelerator opening detecting means 126 is an accelerator opening A that is an accelerator pedal operation amount by an accelerator opening sensor._CCAn accelerator opening signal representing is detected. For example, accelerator opening A_CCIs fully closed, that is, the accelerator is off, the accelerator opening A_CCIs a value determined to be fully closed, for example, it is determined when the fully closed switch is turned on. Further, the state in which the accelerator pedal is operated, that is, the accelerator on is determined, for example, when the fully closed switch is turned off.
[0033]
The fuel cut control means 104 as the fuel supply amount suppression means 102 is an engine speed N_EIn order to improve the fuel efficiency by determining whether or not fuel supply to the engine 10 is necessary based on the accelerator opening degree Acc and the accelerator opening Acc, the stop command C for fuel cut operation, that is, the fuel supply to the engine 10 A stop command C is output to the fuel supply amount suppression device 100. FIG. 12 is a time chart for explaining an example of the fuel cut operation by the fuel cut control means 104. For example, the engine rotational speed N is determined when the vehicle is decelerating when the accelerator opening degree detecting means 126 determines that the accelerator is off._EIs a predetermined value determined in advance, for example, a fuel cut start rotational speed N set to 1400 rpm_EKAnd engine speed N_EWhen the fuel pressure is decreasing, a fuel supply stop command C is output so that the fuel cut operation is started (t in FIG. 12).₁Time). After that, the engine speed N_EIs a predetermined value determined in advance, for example, a fuel cut return rotational speed N set to 1000 rpm._EFWhen the following condition is satisfied, the output of the fuel supply stop command C to the engine 10 is stopped so that the fuel cut operation ends (t in FIG. 12).₂Time). When the fuel cut state is released, the fuel supply is resumed and the engine 10 is started quickly. Note that at least during the fuel cut operation, the lock-up clutch 26 switches the engagement state in the direction in which the lock-up clutch control means 114 increases the engagement force of the lock-up clutch 26 so that the engine speed is not suddenly reduced. Is called. FIG. 13 shows a fuel cut start rotational speed N set in advance based on the engine water temperature._EKAnd fuel cut return speed N_EFIt shows. In this relationship, when the engine water temperature is low, the engine 10 needs to be warmed up compared to when the engine water temperature is high._EKAnd fuel cut return rotational speed N_EFAre set so that the lower the water temperature, the higher the rotation speed. Also, the fuel cut start rotational speed N_EKAnd fuel cut return rotational speed N_EFAre set so as to be constant after warm-up when the engine water temperature becomes equal to or higher than the water temperature during normal operation. Further, the fuel cut control means 104 determines whether or not the engine 10 is in a state where a fuel cut operation is possible. For example, it is determined whether the fuel cut operation is not performed in order to prevent deterioration of the catalyst for reducing harmful components in the exhaust gas of the engine 10 before the engine 10 is warmed up. It is determined whether or not is possible.
[0034]
The drive assist means 122 assists the rotational drive of the engine 10 by operating the first motor generator MG1 or the second motor generator MG2 as a rotational drive device. Fuel cut return rotational speed N_EFFor example, the engine 10 has a stable and smooth engine speed N upon restart._EFor example, the engine speed N that allows smooth autonomous rotation_EFor example, idle speed N_EIDLTo maintain the idling speed N_EIDLEngine speed N at the time of resumption of fuel supply_ESince a certain amount of margin is required, the margin is set to have the margin. Accordingly, the drive assist means 122 is configured to return the fuel cut return rotational speed N_EFFuel cut start rotational speed N_EKAt the same time, it is possible to restart the engine 10 even when the fuel supply is resumed at a lower speed in order to increase the fuel cut region by extending the fuel cut region by extending the fuel cut region, ie, extending the fuel cut operation period to improve fuel efficiency. In addition, the first motor generator MG1 or the second motor generator MG2 is operated to assist the rotational drive of the engine 10.
[0035]
The drive assist availability determination unit 124 determines whether the first motor generator MG1 or the second motor generator MG2 for assisting the drive of the engine 10 by the drive assist unit 122 is operable. For example, whether or not the fuel cell 70 and the secondary battery 71 can function as a power source for supplying sufficient power to the first motor generator MG1 and the second motor generator MG2, for example, the voltage of the fuel cell 70 or the secondary battery 71 The determination is made based on whether the state of charge is equal to or higher than a predetermined reference value, or whether the temperature of the fuel cell 70 and the secondary battery 71 is higher than a predetermined reference temperature.
[0036]
The fuel cut region changing means 110 as the fuel supply set amount changing means 108 determines whether the drive assist means 122 can operate the first motor generator MG1 or the second motor generator MG2 by the drive assist availability determination means 124. The engine speed N for executing the fuel cut operation by the fuel cut control means 104 according to the determination result._E, That is, the fuel cut start rotational speed N_EKAnd fuel cut return speed N_EFChange the fuel cut area set in and. That is, when the operation of the first motor generator MG1 or the second motor generator MG2 for assisting the driving of the engine 10 is not possible, the fuel cut region is provided with the first motor generator MG1 or the second motor generator MG2. Fuel cut starting rotational speed N that is the set value when not_EKAnd return rotation speed N_EFFor example, 1400 and 1000 rpm. Further, when the operation of the first motor generator MG1 or the second motor generator MG2 is possible, the engine speed N is lower than that when the operation is not possible._EHowever, since the engine 10 can be restarted, the fuel cut start rotational speed N, which is a lower set value of the fuel cut region, is set._EKAnd return rotation speed N_EFFor example, 650 and 550 rpm are set.
[0037]
The lockup clutch control means 114, for example, from the previously stored lockup area diagram shown in FIG._OUTAccelerator opening A indicating the driver's required output amount_CCOr throttle opening θ_THBased on (%), it is determined whether the region belongs to the engagement region, the release region, or the slip region, and the lock-up control solenoid in the hydraulic control circuit 66 is operated so as to operate the determined region. To control the lock-up clutch 26 to be engaged, released, or slipped. Here, the engagement side in the engagement state of the lockup clutch 26 is a side where the engagement force of the lockup clutch 26 is large, for example, a lockup on state or a slip state, and the engagement state of the lockup clutch 26. The release side is a side where the engagement force of the lock-up clutch 26 is small, for example, a lock-up off state or a slip state. For example, the switching of the engagement state in the direction to decrease the engagement force of the lockup clutch 26 is a switch from the engagement side to the release side of the lockup clutch 26, and the engagement force of the lockup clutch 26 is reduced. Switching of the engagement state in the increasing direction is switching from the release side of the lockup clutch 26 to the engagement side.
[0038]
The lock-up clutch control means 114 has an accelerator opening A._CCOr throttle opening θ_THWhen fully closed, for example, the engagement state of the lockup clutch 26 is switched according to the point a or the point b which is the lockup operation point when the accelerator is off as shown in FIG. As a result, the fuel cut operation by the fuel cut control means 104 is executed for the purpose of improving fuel efficiency during deceleration traveling when the vehicle speed V is the lock-up on operation point b, that is, when the accelerator is off at the vehicle speed Vb or higher. The engagement state of the clutch 26 is switched to the engagement side, and the pump impeller 20 is rotated integrally or following the turbine impeller 24 to rotate the engine speed N._EAs a fuel cut region, the fuel cut operation is continued. Further, if the vehicle speed V is decelerated from the point a which is the lock-up off operation point, that is, the vehicle speed Va, the engine speed N is reached._ESuddenly drops, fuel cut return speed N_EFThe fuel cut operation is stopped, that is, the fuel supply to the engine 10 is resumed. FIG. 14A shows, for example, a part of the vicinity of the accelerator-off state in the lock-up region diagram of FIG. 9 extracted from the acceleration lock-up region line (lock-up on-region line) indicated by a solid line. This is indicated by a deceleration lockup area line (lockup off area line) indicated by a broken line. Although the slip control region (slip state region) is omitted, the slip region may be suitably implemented in the engagement side region.
[0039]
The lockup operation point changing means 118 is used to change the lockup operation point when the accelerator is off, which is used for switching the engagement state of the lockup clutch 26 by the lockup clutch control means 114, to start the fuel cut by the fuel cut area changing means 110. Rotational speed N_EKAnd fuel cut return speed N_EFThe fuel cut area set in and is changed according to the change result. For example, when the fuel cut area is changed to the low rotation speed side of the engine rotation speed by the fuel cut area changing means 110, the lockup operation point is changed to be set to the lower vehicle speed side. This is because when the fuel cut operation is set to be executed to the lower engine speed side, the switching of the engagement state of the lockup clutch to the engaged side is continued to the lower vehicle speed side accordingly. This is because the fuel cut operation is continued for a long time. Moreover, if the switching to the engagement side of the lockup clutch 26 is executed at a lower vehicle speed, the deceleration shock is reduced. For example, if the fuel cut region is a set value when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible, for example, 1400 and 1000 rpm, the lockup operation point is set to the points a and b shown in FIG. If the set value is set and the first motor generator MG1 or the second motor generator MG2 can be operated, for example, at 650 and 550 rpm, the lock-up operating points are indicated by points a and b shown in FIG. Further, the point a ′ and the point b ′ shown in FIG. As a result, when the lockup operating point is changed to point a ′ and point b ′ in FIG. 14B, if the vehicle speed V is equal to or higher than point b ′, that is, Vb ′, the lockup is essentially off. However, the lock-up clutch is switched to the engagement side by turning off the accelerator, and the switch-up to the engagement side of the lock-up clutch 26 is continued until the vehicle speed V is decelerated from the point a ′, that is, Va ′. Compared with the case where the operating point is set to point a and point b in FIG. 14A, the state of switching to the engagement side of the lockup clutch 26 is continued to the lower vehicle speed side, and the fuel cut operation is longer. Will continue.
[0040]
The lock-up clutch switching determining means 120 is locked by the lock-up clutch control means 114 for the fuel cut operation according to the lock-up operating point changed and set by the lock-up operating point changing means 118 during the deceleration traveling with the accelerator off. It is determined whether it is necessary to switch the engagement state of the up clutch 26. For example, when the accelerator opening is fully closed based on the lockup area diagram of FIG. 14, the point indicating the vehicle traveling state determined by the actual accelerator opening and vehicle speed is the lockup on area line. From the lower vehicle speed side region, that is, from the release side region of the lock-up clutch 26, the lock-up operation point is changed to the engagement side region at the point b or the point b 'or more to switch to the engagement side of the lock-up clutch 26 It is determined whether or not is necessary. The lockup clutch control means 114 executes the switching of the lockup clutch 26 when the lockup clutch switching determination means 120 determines that the engagement state of the lockup clutch 26 needs to be switched.
[0041]
The engine speed determination means 128 is configured to detect the current engine speed N detected by the engine speed sensor._EHowever, the fuel cut return rotational speed N set by the fuel cut region changing means 110 used when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible._EFFor example, it is determined whether it is lower than 1000 rpm.
[0042]
FIG. 15 shows the main part of the control operation of the electronic control unit 90 according to the first embodiment, that is, the lock-up operation point according to the change of the fuel cut region for the fuel cut operation when the vehicle is decelerated while the accelerator is off. FIG. 16 is a time chart for explaining the engagement state switching control operation of the lockup clutch 26 to be changed, and FIG. 16 is a time chart for explaining the engagement state switching control operation. In FIG. 15, it is determined whether or not the accelerator is turned off from the accelerator on in step (hereinafter, step is omitted) SA1 corresponding to the accelerator opening detecting means 126, for example, accelerator opening A._CCIs determined based on a value determined to be fully closed, for example, whether or not the fully closed switch is turned on. If the determination at SA1 is negative, this routine is terminated. If the determination is affirmative, at SA2 corresponding to the drive assist enable / disable determining means 124, the fuel cut region is set to the low engine speed side. Whether or not the operation of the first motor generator MG1 or the second motor generator MG2 for assisting the driving of the engine 10 by the drive assist means 122 is possible is, for example, whether the fuel cell 70 and the secondary battery 71 are the first motor generator. It is determined by whether or not it can function as a power source for supplying sufficient power to MG1 and second motor generator MG2.
[0043]
When the determination of SA2 is affirmative, in SA3 corresponding to the fuel cut region changing unit 110 as the fuel supply set amount changing unit 108, the fuel cut region is on the engine low speed side, for example, the fuel cut start rotational speed N_EKAnd return rotation speed N_EFIs set to 650 and 550 rpm, for example. In SA4 corresponding to the lockup operation point changing means 118, the fuel cut region is changed to the low rotation speed side of the engine rotation speed in SA3, so that the lockup operation point is also changed to the low vehicle speed side according to the change result. Is set to change. For example, the lock-up operation point is set at a point a ′ and a point b ′ shown in FIG. 14B which are set at a lower speed side by a predetermined value than the points a and b shown in FIG. Similarly, when the determination of SA2 is negative, in SA10 corresponding to the fuel cut area changing means 110 as the fuel supply set amount changing means 108, the fuel cut area is on the high engine speed side of the engine speed, for example, Setting value when the first motor generator MG1 or the second motor generator MG2 is not provided, for example, the fuel cut start rotational speed N_EKAnd return rotation speed N_EFIs set to 1400 and 1000 rpm. Next, in SA11 corresponding to the lockup operation point changing means 118, since the fuel cut region is changed to the high rotation speed side of the engine rotation speed in SA10, the lockup operation point is also changed to the high vehicle speed side according to the change result. Is set to change. For example, the lock-up operation point is set to point a and point b shown in FIG. That is, in SA3 to SA4 or SA10 to SA11, the fuel cut area is changed and set by the fuel cut area changing means 110 according to the determination result by the drive assist availability determining means 124, and the lockup operation point is changed according to the set result. The lock-up operating point is changed and set by means 118.
[0044]
Subsequently, in SA5 corresponding to the lockup clutch switching determination means 120, the lockup clutch by the lockup clutch control means 114 for the fuel cut operation according to the lockup operation point changed and set by the lockup operation point changing means 118. It is determined whether or not it is necessary to switch the engagement state. For example, when the accelerator is turned off based on the lock-up region diagram of FIG. 14, the point indicating the vehicle running state determined by the actual accelerator opening and vehicle speed is from the disengagement side region of the lock-up clutch 26 to the engagement side region. Thus, it is determined whether or not it is necessary to switch the lockup clutch 26 to the engagement side. If the determination of SA5 is negative, the current state is maintained and the routine is terminated in SA12 corresponding to the lockup clutch control means 114, but if the determination is affirmative, the routine corresponds to the lockup clutch control means 114. In SA6, the lockup clutch 26 is switched to the engagement side in accordance with the lockup operation point set in SA4 or SA11 (t in FIG. 16).₁Time).
[0045]
Next, in SA7 corresponding to the drive assist enable / disable determining means 124, whether or not the operation of the first motor generator MG1 or the second motor generator MG2 is impossible during the fuel cut operation is the same as SA2. Determined. If the determination at SA7 is affirmative, at SA12 corresponding to the lockup clutch control means 114, the current state is maintained and the engine speed N_EIs the return rotational speed N set in SA4 above._EF(550 rpm) until below (t in FIG. 16_ThreeThe fuel cut operation is continued and this routine is terminated. If the determination is negative, the current engine speed N detected by the engine speed sensor is detected in SA8 corresponding to the engine speed determination means 128._EIs set in SA11 or is a value stored in advance because it is set, the fuel cut return rotational speed N when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible._EFFor example, it is determined whether it is lower than 1000 rpm.
[0046]
If this SA8 is negative, the current engine speed N_EIs the fuel cut return rotational speed N when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible._EFAs described above, even if the driving of the engine 10 is not assisted by the operation of the first motor generator MG1 or the second motor generator MG2, the engine speed N_EIs the return rotational speed N set in SA11._EFUntil it becomes 1000 rpm or less (t in FIG. 16₂The fuel cut operation is continued and this routine is terminated. However, if the determination is affirmative, the fuel cut operation is stopped and the fuel supply to the engine 10 is resumed at SA9 corresponding to the fuel cut control means 104 and the lockup clutch control means 114 as the fuel supply amount suppression means 102. . Thereafter, the engagement state of the lockup clutch 26 is switched to lockup off. If the lockup is turned off before the resumption of fuel supply to the engine 10 in SA9, the engine speed decreases, and the engine 10 is driven by the operation of the first motor generator MG1 or the second motor generator MG2. Since it may be difficult to restart the engine 10 without assistance, the fuel supply to the engine 10 is restarted first. As described above, when the assist of the rotational torque of the engine 10 by the operation of the first motor generator MG1 or the second motor generator MG2 is possible, the fuel cut operation is executed longer than when it is not possible. Further, since the switching to the engagement side of the lockup clutch 26 is executed at a lower vehicle speed, the deceleration shock is reduced.
[0047]
As described above, according to the first embodiment, when it is determined that the accelerator or the throttle is fully closed while the vehicle is decelerating, the fuel cut control means 104 serving as the fuel supply amount suppression means 102 is applied to the engine 10. When the relationship of the fuel supply amount with respect to the preset engine speed for executing the fuel supply suppression is changed by the fuel cut region changing means 110 (SA3, SA10) as the fuel supply set amount changing means 108. The lock-up clutch control means 114 (SA6) has a preset lock-up operating point for switching the engagement state of the lock-up clutch 26. The engine speed N_EIs changed by the lockup operation point changing means 118 (SA4, SA11) in accordance with the change in the relationship of the fuel supply amount to the engine speed N._EThe timing of switching the engagement state of the lockup clutch 26 by changing the relationship of the fuel supply amount to the engine and the change of the lockup operating point thereof is matched, for example, switching to the engagement side of the lockup clutch 26 at a lower vehicle speed Therefore, deceleration shock is reduced and drivability is improved. For example, the engine speed N_EWhen the relationship of the fuel supply amount to the engine is changed to the low engine speed side, the lockup operating point is also changed to the low vehicle speed side, that is, the low engine speed side corresponding to the vehicle speed during deceleration. The fuel supply control time becomes longer and the fuel consumption is improved.
[0048]
Further, according to the first embodiment, the engine speed N_EThe relationship between the fuel supply amount and the engine speed N_EIncludes a fuel cut region for stopping fuel supply to the engine 10 by the fuel supply amount suppression means 102 when the engine speed is higher than a predetermined return rotational speed, and includes a lockup operation point changing means 118 (SA4, SA11). ) Changes the lock-up operating point when the accelerator or throttle is determined to be fully closed according to the change of the fuel cut region by the fuel supply set amount changing means 108 (SA3, SA10). When the fuel cut region is changed by the fuel supply set amount changing means 108 (SA3, SA10), a preset is made for switching the engagement state of the lockup clutch 26 by the lockup clutch control means 114 (SA6). The locked-up activation point is changed to change its fuel cut area Accordingly, the change is made by the lockup operation point changing means 118 (SA4, SA11), so that the change timing of the engagement state of the lockup clutch by the change of the fuel cut region and the change of the lockup operation point is matched. Improved drivability. Further, for example, when the fuel cut region is changed to the low engine speed side, the lockup operating point is also changed to the low vehicle speed side, that is, the low engine speed side corresponding to the vehicle speed during deceleration. The stop time of the fuel supply to 10 becomes longer and the fuel consumption improves.
[0049]
Further, according to the first embodiment, the rotational drive devices (first motor generator MG1 and second motor generator MG2) operatively connected to the engine 10 and the rotational drive devices are operated to operate the engine rotational speed N._EDrive assist means 122 for assisting the rotation of the engine 10 and the rotation assist device 122 is operated by the drive assist means 122 to rotate the rotational speed N of the engine 10._EDrive assist enable / disable determining means 124 (SA2) for determining whether or not it is possible to assist, and the fuel supply set amount changing means 108 (SA3, SA10) according to the determination result by the drive assist enable / disable determining means 124 Since the fuel cut area is changed, it is determined by the drive assist availability determination means 124 whether or not the rotational speed (drive) of the engine can be assisted by the operation of the rotation drive device by the drive assist means 122, and the fuel supply setting is made. Since the fuel cut region is changed by the amount changing means 108 according to the determination result, for example, the engine speed N by the rotary drive device_EWhen it is possible to assist the engine, the fuel cut region is preferably changed to the low engine speed side.
[0050]
Further, according to the first embodiment, the lock-up operating point changing means 118 (SA4, SA11) has the fuel cut region changed to the high engine speed side by the fuel supply set amount changing means 108 (SA3, SA10). Then, since the lock-up operating point is changed to the high vehicle speed side, the timing of switching the engagement state of the lock-up clutch 26 is matched, and drivability is improved.
[0051]
Further, according to the first embodiment, the lockup clutch control means 114 (SA6) is operated by the drive assist availability determination means 124 (SA7) while the fuel supply amount suppression means 102 stops the fuel supply to the engine 10. Engine speed N by drive assist means 122_EIf the fuel supply amount suppression means 102 stops stopping the fuel supply to the engine 10 and the fuel supply is resumed, the lockup clutch 26 is locked up and off. Therefore, before the fuel supply to the engine 10 is resumed, the lockup is turned off and the engine speed N_EThe possibility that the engine 10 is not restarted due to a decrease in the engine speed is solved.
[0052]
Next, a second embodiment of the present invention will be described. In the following description, parts common to those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
[0053]
Since the second embodiment is common to the above-described first embodiment in the vehicle configuration of FIGS. 1 to 10, the description thereof will be omitted. The major difference from the first embodiment is that the fuel supply amount suppression means 102 is replaced with a fuel cut control means 104 and replaced with a fuel reduction control means 106. In short, the fuel cut control means 104 stops the fuel supply to the engine 10, while the fuel reduction control means 106 determines the engine speed N according to a predetermined relationship._EThe fuel supply amount to the engine 10 is reduced to improve the fuel efficiency. The parts different from the first embodiment will be described in detail with reference to FIG.
[0054]
In FIG. 11, a fuel reduction control means 106 is used instead of the fuel cut control means 104 used as the fuel supply amount suppression means 102 in the first embodiment. This fuel reduction control means 106 is provided with an engine speed N_EIn order to improve the fuel consumption by determining whether or not it is necessary to reduce the fuel supply amount (fuel injection amount) to the engine 10 based on the accelerator opening degree Acc and the like, the command for the fuel supply amount reduction operation D, that is, a fuel supply amount reduction command D to the engine 10 is output to the fuel supply amount suppression device 100 based on, for example, a fuel reduction line shown by a solid line in FIG. FIG. 17 shows the engine speed N that is used by the fuel reduction control means 106 when the accelerator-off vehicle is decelerating._EFIG. 5 is a relationship diagram set in advance in which the fuel supply amount based on the above is determined. According to the solid line in FIG. 17, the fuel supply amount (fuel injection amount) is the engine speed N_EIs a predetermined value determined in advance, and the fuel supply resumption rotational speed N_EAIf it is above, it becomes zero, that is, the fuel cut state, and the fuel supply resumption rotational speed N_EAOn the lower rotational speed side, the fuel supply to the engine 10 is resumed and the engine rotational speed N_EAs the speed decreases, the idle speed N_EIDLSupply amount F_IDLIs set in advance so as to be gradually increased. Fuel supply resumption rotational speed N_EAMay be suitably set according to the characteristics or type of the engine 10. Also, the engine speed N_EIs the fuel supply restart speed N_EAIf it is above, it becomes a fuel cut state, and if it falls below that, the fuel supply is resumed._EAFor example, the fuel cut return rotational speed N that defines the fuel cut region_EFAnd fuel cut start rotational speed N_EKFor example, the fuel cut start rotational speed N_EKThe fuel supply resumption rotational speed N is equivalent to_EAA predetermined rotation speed may be set on the higher rotation speed side. The lock-up clutch 26 has at least an engine speed N_EIs the fuel supply restart speed N_EADuring the fuel cut state described above, the engine speed N_ETherefore, the lockup clutch control means 114 needs to switch to the engagement side of the lockup clutch 26 so as not to be suddenly lowered.
[0055]
The drive assist means 122 assists the rotational drive of the engine 10 by operating the first motor generator MG1 or the second motor generator MG2 as a rotational drive device. In the first embodiment, the fuel cut return rotational speed N_EFFuel cut start rotational speed N_EKIn order to enlarge the fuel cut region by setting to a lower rotational speed side, the fuel supply resumption rotational speed N is increased in the second embodiment._EAFor example, the engine 10 has a stable and smooth engine speed N upon restart._EFor example, the engine speed N that allows smooth autonomous rotation_EFor example, idle speed N_EIDLTo maintain the idling speed N_EIDLEngine speed N at the time of resumption of fuel supply_ESince a certain amount of margin is required, the margin is set to have the margin. Therefore, this fuel supply resumption rotational speed N_EAIs set to a lower rotational speed side to enlarge the region where the fuel cut state is set and the fuel supply amount F_IDLIn order to further reduce the fuel supply amount that is gradually increased so as to improve the fuel efficiency, even when the fuel supply is restarted at a lower speed of the engine 10, its idle speed N_EIDLSupply amount F_IDLThe first motor generator MG1 or the second motor generator MG2 is operated so as to assist the rotational drive of the engine 10.
[0056]
The drive assist availability determination unit 124 determines whether the first motor generator MG1 or the second motor generator MG2 for assisting the drive of the engine 10 by the drive assist unit 122 is operable. For example, whether or not the fuel cell 70 and the secondary battery 71 can function as a power source for supplying sufficient power to the first motor generator MG1 and the second motor generator MG2, for example, the voltage of the fuel cell 70 or the secondary battery 71 The determination is made based on whether the state of charge is equal to or higher than a predetermined reference value, or whether the temperature of the fuel cell 70 and the secondary battery 71 is higher than a predetermined reference temperature.
[0057]
A fuel reduction line changing means 112 is used instead of the fuel cut region changing means 110 used as the fuel supply set amount changing means 108 in the first embodiment. The fuel reduction line changing unit 112 determines whether the fuel assist line determination unit 124 determines whether the first motor generator MG1 or the second motor generator MG2 can be operated by the drive assist unit 122 according to the determination result. The fuel reduction line for executing the operation of reducing the amount of fuel supply to the engine 10 by the reduction control means 106 is changed. That is, when the operation of the first motor generator MG1 or the second motor generator MG2 for assisting the rotational drive of the engine 10 is not possible, the first motor generator MG1 or the second motor generator MG2 includes a fuel reduction line. For example, a setting when the line is not set is shown by a solid line in FIG. Further, when the operation of the first motor generator MG1 or the second motor generator MG2 is possible, the fuel reduction line is connected to the lower rotational speed side, for example, the fuel supply restarting rotational speed N compared to the case where the operation is not possible._EAThe fuel supply restart speed N_EMAOr N_EMBThe fuel supply amount F_IDLFor example, a line indicated by a one-dot chain line or a two-dot chain line in FIG.
[0058]
Similarly to the first embodiment, the lockup clutch control means 114 is configured to output a vehicle speed V (output-side rotational speed N) representing an actual vehicle running state from a lockup area diagram stored in advance as shown in FIG._OUTAccelerator opening A indicating the driver's required output amount_CCOr throttle opening θ_THBased on (%), it is determined whether the region belongs to the engagement region, the release region, or the slip region, and the lock-up control solenoid in the hydraulic control circuit 66 is operated so as to operate the determined region. To control the lock-up clutch 26 to be engaged, released, or slipped.
[0059]
Further, in the first embodiment, the lockup clutch control means 114 switches the lockup clutch 26 to the engagement side in order to execute the fuel cut operation by the fuel cut control means 104 for the purpose of improving fuel efficiency. In the second embodiment, the engine speed N at which the fuel cut state is achieved by at least the fuel reduction control means 106 for the purpose of improving fuel efficiency._EFor example, the fuel supply restart speed N_EAAs described above, the lockup clutch 26 is switched to the engagement side. That is, the accelerator opening A is the same as in the first embodiment._CCOr throttle opening θ_THWhen fully closed, for example, the engagement state of the lockup clutch 26 is switched according to the point a or the point b which is the lockup operation point when the accelerator is off as shown in FIG. As a result, at the time of decelerating when the vehicle speed V is at the lock-up on operation point b, ie, Vb or higher, and the vehicle is decelerated, a fuel cut state to the engine 10 by the fuel reduction control means 106 is made at least for the purpose of improving fuel efficiency. For example, the engine speed is changed so that the fuel cut state continues longer by switching the engagement state of the lock-up clutch 26 to the engagement side and rotating the pump impeller 20 integrally or following the turbine impeller 24. N_EThe fuel supply restart speed N_EAThe above period is continued longer. Further, if the vehicle speed V is decelerated from the point a which is the lock-up off operation point, that is, Va, and the lock-up off state is entered, the engine speed N_ESuddenly drops and fuel supply resumes rotation speed N_EAThe fuel cut state is stopped and fuel supply to the engine 10 is resumed.
[0060]
The lock-up operating point changing means 118 is a lock-up operating point when the accelerator is off, which is used for switching the engagement state of the lock-up clutch 26 by the lock-up clutch control means 114. In the first embodiment, the fuel cut area changing means is changed. Although it changed according to the result by which the fuel cut area | region by the means 110 was changed, in the 2nd Example, it changes according to the result by which the fuel reduction line by the said fuel reduction line change means 112 was changed. For example, the fuel reduction line is changed to the engine speed N by the fuel reduction line changing means 112._EThe low rotation speed side, that is, the side where the amount of fuel supplied to the engine 10 is further reduced, for example, in FIG._EAIs N_EMAWhen the solid line is changed to the alternate long and short dash line, the lockup operating point is changed to be set to the lower vehicle speed side. This is the fuel supply resumption rotational speed N_EAWhen the fuel cut state described above is set to be executed to the engine low speed side, switching of the lockup clutch to the engagement side is continued to the low vehicle speed side accordingly. This is because the fuel cut state is continued for a long time. Moreover, if the switching to the engagement side of the lockup clutch 26 is executed at a lower vehicle speed, the deceleration shock is reduced. For example, if the fuel reduction line is not capable of operating the first motor generator MG1 or the second motor generator MG2, for example, if it is a solid line in FIG. 17, the lock-up operating points are set at points a and b shown in FIG. Further, when the operation of the first motor generator MG1 or the second motor generator MG2 is possible, for example, in the case of the alternate long and short dash line in FIG. 17, the lock-up operation point is determined more than the points a and b shown in FIG. The values are set at the points a ′ and b ′ shown in FIG. As a result, when the lockup operating point is changed to point a ′ and point b ′ in FIG. 14B, if the vehicle speed V is equal to or higher than point b ′, that is, Vb ′, the lockup is essentially off. However, when the accelerator is off, the lockup clutch is switched to the engagement side, and the switchover to the engagement side of the lockup clutch is continued until the vehicle speed V is decelerated from the point a ′, that is, Va ′. Compared with the case where the points are set to points a and b in FIG. 14A, the switching state of the lock-up clutch 26 to the engagement side is continued to the lower vehicle speed side and the fuel cut state continues for a longer time. Is done.
[0061]
The lockup clutch switching determination means 120 supplies fuel to the engine 10 in accordance with the lockup operating point changed and set by the lockup operating point changing means 118 during the deceleration traveling in which the accelerator is turned off as in the first embodiment. It is determined whether or not it is necessary to switch the engagement state of the lockup clutch 26 by the lockup clutch control means 114 for the amount reduction operation. For example, when the accelerator opening is fully closed based on the lockup area diagram of FIG. 14, the point indicating the vehicle traveling state determined by the actual accelerator opening and vehicle speed is the lockup on area line. From the lower vehicle speed side region, that is, from the release side region of the lock-up clutch 26, the lock-up operation point is changed to the engagement side region at the point b or the point b 'or more to switch to the engagement side of the lock-up clutch 26 It is determined whether or not is necessary. The lockup clutch control means 114 executes the switching of the lockup clutch 26 when the lockup clutch switching determination means 120 determines that the engagement state of the lockup clutch 26 needs to be switched.
[0062]
In the first embodiment, the engine rotation speed determination means 128 is the fuel cut return rotation speed N._EFIn the second embodiment, the current engine speed N detected by the engine speed sensor is compared with_EHowever, the fuel supply resumption rotational speed N set by the fuel reduction line changing means 112 used when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible._EAIt is determined whether or not it is lower.
[0063]
FIG. 18 shows the control operation of the electronic control unit 90 according to the second embodiment, that is, according to the change of the fuel reduction line for the operation of reducing the fuel supply amount to the engine 10 when the vehicle is decelerated while the accelerator is off. FIG. 19 is a time chart illustrating the engagement state switching control operation of the lockup clutch 26 in which the lockup operation point is changed, and FIG. 19 is a time chart illustrating the engagement state switching control operation. . In FIG. 18, whether or not the accelerator is turned on from the accelerator on is determined in step (hereinafter, step is omitted) SB1 corresponding to the accelerator opening detecting means 126, for example, accelerator opening A._CCIs determined based on a value determined to be fully closed, for example, whether or not the fully closed switch is turned on. If the determination at SB1 is negative, this routine is terminated. If the determination is affirmative, at SB2 corresponding to the drive assist availability determination means 124, the fuel reduction line is set to the low engine speed side. Whether or not the operation of the first motor generator MG1 or the second motor generator MG2 for assisting the driving of the engine 10 by the drive assist means 122 is possible is, for example, whether the fuel cell 70 and the secondary battery 71 are the first motor generator. It is determined by whether or not it can function as a power source for supplying sufficient power to MG1 and second motor generator MG2.
[0064]
If the determination of SB2 is affirmative, in SB3 corresponding to the fuel reduction line changing means 112 as the fuel supply set amount changing means 108, the fuel reduction line is on the low engine speed side, for example, a one-dot chain line shown in FIG. Is set. In SB4 corresponding to the lockup operation point changing means 118, the fuel reduction line is changed to the low rotation speed side of the engine rotation speed in SB3, so that the lockup operation point is also changed to the low vehicle speed side according to the change result. Is set to change. For example, the lock-up operation point is set at a point a ′ and a point b ′ shown in FIG. 14B which are set at a lower speed side by a predetermined value than the points a and b shown in FIG. Similarly, when the determination of SB2 is negative, in SB10 corresponding to the fuel reduction line changing means 112 as the fuel supply set amount changing means 108, the fuel reduction line is on the high engine speed side of the engine speed, for example, A set value when the first motor generator MG1 or the second motor generator MG2 is not provided, for example, a solid line shown in FIG. Next, in SB11 corresponding to the lockup operation point changing means 118, since the fuel reduction line is changed to the high rotation speed side of the engine rotation speed in SB10, the lockup operation point is also changed to the high vehicle speed side according to the change result. Is set to change. For example, the lock-up operation point is set to point a and point b shown in FIG. That is, in SB3 to SB4 or SB10 to SB11, the fuel reduction line is changed and set by the fuel reduction line changing means 112 according to the determination result by the drive assist availability determination means 124, and the lockup operation point is changed according to the set result. The lock-up operating point is changed and set by means 118.
[0065]
Subsequently, at SB5 corresponding to the lockup clutch switching determination means 120, the lockup clutch control is performed for reducing the fuel supply amount to the engine 10 according to the lockup operation point changed and set by the lockup operation point changing means 118. It is determined whether or not it is necessary to switch the engagement state of the lockup clutch 26 by means 114. For example, when the accelerator is turned off based on the lock-up region diagram of FIG. 14, the point indicating the vehicle running state determined by the actual accelerator opening and vehicle speed is from the disengagement side region of the lock-up clutch 26 to the engagement side region. Thus, it is determined whether or not it is necessary to switch the lockup clutch 26 to the engagement side. If the determination at SB5 is negative, the current state is maintained and the routine is terminated at SB12 corresponding to the lock-up clutch control means 114. If the determination is affirmative, the routine corresponds to the lock-up clutch control means 114. In SB6, the lockup clutch 26 is switched to the engagement side in accordance with the lockup operation point set in SB4 or SB11 (t in FIG. 19).₁Time).
[0066]
Next, in SB7 corresponding to the drive assist availability determination means 124, whether or not the operation of the first motor generator MG1 or the second motor generator MG2 is not possible during the fuel cut operation is the same as in SB2. Determined. If the determination at SB7 is affirmative, the current state is maintained at SB12 corresponding to the lockup clutch control means 114, and the engine speed N_EIs the fuel supply resumption rotational speed N according to the fuel reduction line shown by the one-dot chain line in FIG._EMAUntil the following (t in FIG. 16_Three(Up to the time point) At least the lock-up clutch is engaged and the fuel cut state is continued. Thereafter, the fuel supply to the engine 10 is resumed and the idle speed N_EIDLUntil the fuel supply amount is gradually increased (t in FIG. 16)._FourTime) This routine is terminated, but if the determination is negative, the current engine speed N detected by the engine speed sensor is detected in SB8 corresponding to the engine speed determination means 128._EIs set in SB11 or is a value stored in advance so that the fuel set by the fuel reduction line shown by the solid line in FIG. 17 when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible. Supply restarting speed N_EAOr lower is determined.
[0067]
If this SB8 is denied, the current engine speed N_EIs the fuel supply resumption rotational speed N when the operation of the first motor generator MG1 or the second motor generator MG2 is not possible._EAAs described above, even if the driving of the engine 10 is not assisted by the operation of the first motor generator MG1 or the second motor generator MG2, the engine speed N_EIs the fuel supply resumption rotational speed N set in SB11._EAUntil (t in FIG. 19₂(Up to the time point) At least the lock-up clutch is engaged and the fuel cut state is continued. Thereafter, the fuel supply to the engine 10 is resumed and the idle speed N_EIDLUntil the fuel supply amount is gradually increased (t in FIG. 16)._FourTime) This routine is terminated. However, if the determination is affirmative, at SB9 corresponding to the fuel reduction control means 106 and the lockup clutch control means 114 as the fuel supply amount suppression means 102, the fuel cut state is stopped and the fuel supply to the engine 10 is resumed. . Thereafter, the engagement state of the lockup clutch 26 is switched to lockup off. If the lockup is turned off prior to the resumption of fuel supply to the engine 10 in SB9, the engine speed decreases and the engine 10 is driven by the operation of the first motor generator MG1 or the second motor generator MG2. Since it may be difficult to restart the engine 10 without assistance, the fuel supply to the engine 10 is restarted first. As described above, when the assist of the rotational torque of the engine 10 by the operation of the first motor generator MG1 or the second motor generator MG2 is possible, the fuel cut state is executed longer than when it is not possible. Thus, the subsequent fuel supply amount is further reduced, and the switching to the engagement side of the lockup clutch 26 is executed at a lower vehicle speed, so that the deceleration shock is reduced.
[0068]
As described above, according to the second embodiment, when it is determined that the accelerator or the throttle is fully closed while the vehicle is decelerating, the fuel reduction control means 106 serving as the fuel supply amount suppression means 102 applies to the engine 10. When the relationship between the fuel supply amount and the preset engine speed for executing the fuel supply suppression is changed by the fuel reduction line changing means 112 (SB3, SB10) as the fuel supply set amount changing means 108. The lockup operation point set in advance for switching the engagement state of the lockup clutch 26 by the lockup clutch control means 114 (SB6) is the engine speed N._EIs changed by the lockup operation point changing means 118 (SB4, SB11) according to the change in the relationship of the fuel supply amount to the engine rotation speed N._EThe timing of switching the engagement state of the lockup clutch 26 by changing the relationship of the fuel supply amount to the engine and the change of the lockup operating point thereof is matched, for example, switching to the engagement side of the lockup clutch 26 at a lower vehicle speed Therefore, deceleration shock is reduced and drivability is improved. For example, the engine speed N_EWhen the relationship of the fuel supply amount to the engine is changed to the low engine speed side, the lockup operating point is also changed to the low vehicle speed side, that is, the low engine speed side corresponding to the vehicle speed during deceleration. The fuel supply control time becomes longer and the fuel consumption is improved.
[0069]
Further, according to the second embodiment, the engine speed N_EThe relationship between the fuel supply amount and the engine rotation speed N for reducing the fuel supply to the engine 10 by the fuel supply amount suppressing means 102 is as follows._EA fuel reduction line in which the fuel supply amount with respect to is set in advance, and the lock-up operation point changing means 118 (SB4, SB11) responds to the change of the fuel reduction line by the fuel supply set amount changing means 108 (SB3, SB10). Since the lockup operating point when the accelerator or throttle is determined to be fully closed is changed, when the fuel reduction line is changed by the fuel supply set amount changing means 108, the lockup clutch control means 114 (SB6). ) Is changed by the lock-up operation point changing means 118 according to the change of the fuel reduction line, so that the lock-up operation point set in advance for switching the engagement state of the lock-up clutch 26 is changed. The engagement state of the lockup clutch 26 by changing the fuel reduction line and changing the lockup operating point The switchover is improved has been drivability matching. Further, for example, when the fuel reduction line is changed to the engine low rotation speed side, that is, the fuel supply amount reduction side, the lockup operating point is also changed to the low vehicle speed side, that is, the low rotation speed corresponding to the vehicle speed during deceleration. Since the speed is changed to the high speed side, the fuel supply time to the engine is reduced and the fuel consumption is improved.
[0070]
Further, according to the second embodiment, the rotational drive devices (first motor generator MG1 and second motor generator MG2) operatively connected to the engine 10 and the rotational drive devices are operated to operate the engine rotational speed N._EDrive assist means 122 for assisting the engine, and the drive assist means 122 actuates the rotational drive device to rotate the rotational speed N of the engine 10._EDrive assistability determining means 124 (SB2) for determining whether or not the vehicle can be assisted, and the fuel supply set amount changing means 108 (SB3, SB10) according to the determination result by the drive assist availability determining means 124 Since the fuel reduction line is to be changed, it is determined by the drive assist enable / disable determining means 124 whether or not the rotational speed (drive) of the engine can be assisted by the operation of the rotational drive device by the drive assist means 122, and the fuel supply setting is made. Since the fuel reduction line is changed by the amount changing means 108 according to the determination result, for example, the engine rotation speed N by the rotary drive device is changed._EWhen it is possible to assist the fuel, the fuel reduction line is preferably changed to the engine low rotation speed side, that is, the side where the fuel supply amount to the engine 10 is reduced.
[0071]
Further, according to the second embodiment, the lock-up operating point changing means 118 (SB4, SB11) has the fuel supply amount corresponding to the engine rotation speed by the fuel supply set amount changing means 108 (SB3, SB10). When changed to the side to be reduced, the lockup operating point is changed to the low vehicle speed side, so that the time for reducing the fuel supply to the engine 10 becomes longer and the fuel consumption is improved.
[0072]
Further, according to the second embodiment, the lockup clutch control means 114 (SB6) performs the drive assist availability determination means 124 (SB7) during the fuel supply reduction control to the engine 10 by the fuel supply amount suppression means 102. The engine speed N by the drive assist means 122 is_EIf the fuel supply amount suppression means 102 stops the fuel supply reduction control to the engine 10 and the fuel supply is resumed, the lockup clutch 26 is locked up and off. Therefore, before the fuel supply to the engine 10 is resumed, the lockup is turned off and the engine speed N_EThe possibility that the engine 10 is not restarted due to a decrease in the engine speed is solved.
[0073]
Next, a third embodiment of the present invention will be described. In the following description, portions common to the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.
[0074]
Since the third embodiment is common to the first and second embodiments in the vehicle configuration shown in FIGS. 1 to 10, the description thereof is omitted. In the following, the differences from the first and second embodiments will be described in detail with reference to FIG.
[0075]
The lockup clutch state determination unit 116 determines the engagement state of the lockup clutch 26 controlled by the lockup clutch control unit 114. For example, it is determined whether or not the lockup clutch 26 is switched to the engagement side by the lockup clutch control means 114 in order to execute the operation of suppressing the fuel supply amount to the engine 10 by the fuel supply amount suppression means 102. . Further, the lock-up clutch control means 114 is premised on that the driving assist means 122 activates the first motor generator MG1 or the second motor generator MG2 as a rotational drive device to assist the drive of the engine 10. It is determined whether or not it is possible to switch the lockup clutch 26 to the engagement side. For example, when the engine oil temperature is low, switching to the engagement side by the lockup clutch control means 114 is impossible, and therefore it is determined whether or not the engine oil temperature is equal to or higher than a predetermined temperature. Further, for example, if it is determined that judder, which is a vibration phenomenon during vehicle braking, has occurred, switching to the engagement side by the lock-up clutch control means 114 is impossible, so whether or not judder determination is output. Determine whether or not.
[0076]
For example, the shift control means 130 determines the actual vehicle speed V and the throttle valve opening θ from the shift map stored in advance shown in FIG._THThe gear position of the automatic transmission 16 is determined based on (engine load).
[0077]
The downshift point changing unit 134 changes the downshift point according to the result of the lockup operation point changing unit changing the lockup operation point. For example, the operating point of the lock-up operating point toward the engagement side of the lock-up clutch 26 is a predetermined turbine rotational speed N._TFor example, when it is set at 1000 rpm, the vehicle speed decreases and the turbine rotational speed N_TDecreases below 1000 rpm and the switching control operation to the engagement side of the lockup clutch 26 is stopped, the engine speed N_ESuddenly declined_EThere is a possibility that the fuel supply amount suppression means 102 stops the fuel supply amount suppression operation to the engine 10 and the fuel efficiency improvement effect is suppressed. Therefore, turbine rotation speed N_TBefore the engine speed falls below a predetermined value, a downshift by the shift control means 130 is performed so that the turbine rotational speed N_TIs raised so that the switching control operation to the engagement side of the lockup clutch 26 is continued. That is, the downshift point changing unit 134 determines the actual vehicle speed V and the throttle valve opening θ from the shift diagram stored in advance by the shift control unit 130._THInstead of performing a downshift based on (engine load), the turbine speed N_TBased on the above, the shift point is changed so that the downshift is executed. This turbine speed N_TThe lock-up operation point of the lock-up clutch 26 is a predetermined turbine rotational speed N._TIs set at a predetermined turbine rotational speed N in consideration of a delay in downshift control, etc._TIt is suitably set where the above is true.
[0078]
The downshift necessity determination unit 132 is configured to detect the turbine rotational speed N detected by the turbine rotational speed sensor 91._T(= Rotational speed N of the input shaft 22_IN) Is compared with a predetermined value to determine whether or not a downshift is necessary. For example, the lockup operating point is the turbine rotational speed N_T, The turbine speed N_TAnd turbine rotation speed N at the lock-up operating point_TFor example, compared with 1000 rpm, turbine rotation speed N_TTherefore, it is determined whether or not a downshift is necessary so that the speed does not fall below 1000 rpm. The shift control means 130 performs a downshift based on the result.
[0079]
FIG. 20 shows a change in the lock-up operation point for the operation of reducing the fuel supply amount to the engine 10 when the vehicle is decelerated while the accelerator is off, that is, the main part of the control operation of the electronic control unit 90 according to the third embodiment. FIG. 21 is a time chart for explaining the shift control operation in which the downshift point is changed accordingly, and FIG. 21 is a time chart for explaining the shift control operation. In FIG. 20, whether or not the accelerator is turned on from the accelerator on in the step (hereinafter, step is omitted) SC1 corresponding to the accelerator opening detecting means 126 is determined, for example, by the accelerator opening A._CCIs determined based on a value determined to be fully closed, for example, whether or not the fully closed switch is turned on. If the determination at SC1 is negative, this routine is terminated. If the determination is affirmative, at SC2 corresponding to the lockup clutch state determination means 116, the drive assist means 122 causes the first motor generator MG1 or second Whether or not switching to the engagement side of the lockup clutch 26 by the lockup clutch control means 114 is possible on the precondition that the motor generator MG2 is operated and the drive of the engine 10 is assisted is determined. For example, it is determined whether or not the engine oil temperature is equal to or higher than a predetermined temperature and whether or not the judder determination is output. If the determination at SC2 is affirmative, at SC3 corresponding to the fuel reduction line changing means 112 as the fuel supply set amount changing means 108, the fuel reduction line is on the engine low speed side, for example, a one-dot chain line shown in FIG. Is set. Then, in SC4 corresponding to the lockup operation point changing means 118, the fuel reduction line is changed to the low engine speed side of the engine speed in SC3, so that the lockup operation point is set to the low vehicle speed according to the change result. Is set to change. For example, the lock-up operation point is set at a point a ′ and a point b ′ shown in FIG. 14B which are set at a lower speed side by a predetermined value than the points a and b shown in FIG. Similarly, when the determination of SC2 is negative, in SC8 corresponding to the fuel reduction line changing means 112 as the fuel supply set amount changing means 108, the fuel reduction line is on the high engine speed side of the engine speed, for example, A set value when the first motor generator MG1 or the second motor generator MG2 is not provided, for example, a solid line shown in FIG. Then, in SC9 corresponding to the lockup operation point changing means 118, the fuel reduction line is changed to the high engine speed side of the engine speed in SC8, so that the lockup operation point is also changed according to the change result. This is not set or changed. For example, the lock-up operating point is set to point a and point b shown in FIG. 14A, or this is not executed. Then, this routine is terminated. That is, in SC3 to SC4, the fuel reduction line by the fuel reduction line changing means 112 is changed and set, and the lockup operating point by the lockup operating point changing means 118 is changed and set according to the set result. If the determination is negative, the lockup clutch 26 cannot be switched to the engagement side, so that the fuel reduction operation to the engine 10 by the fuel reduction control means 106 is not executed after SC8 to SC9 are executed. Further, this routine is terminated without executing downshift.
[0080]
Next, in SC5 corresponding to the lockup clutch state determination means 116, the engagement state of the lockup clutch 26 controlled by the lockup clutch control means 114 indicates, for example, the fuel supplied to the engine 10 by the fuel supply amount suppression means 102. It is determined whether or not the lockup clutch 26 is switched to the engagement side by the lockup clutch control means 114 in order to execute the supply amount suppression operation. If the determination at SC5 is negative, this routine is terminated. If the determination is affirmative, the shift control means 130 pre-selects the routine at SC6 corresponding to the downshift point changing means 134 and the downshift necessity determining means 132. Instead of performing a downshift based on the stored shift map, the turbine rotational speed N_TBased on the above, the shift point is changed so that the downshift is executed. For example, the lockup operating point is the turbine rotational speed N_T, The turbine speed N_TAnd turbine rotation speed N at the lock-up operating point_TFor example, compared with 1000 rpm, turbine rotation speed N_TSet the downshift point so that does not drop below 1000 rpm. Next, the turbine rotational speed N detected by the turbine rotational speed sensor 91_T(= Rotational speed N of the input shaft 22_IN) With a predetermined value, it is determined whether or not a downshift is necessary at the set downshift point. If the determination in SC6 is negative, this routine is terminated. If the determination is positive, in SC7 corresponding to the shift control means 130, a downshift is executed and the turbine rotational speed N_TIs pulled up, and the switching control operation to the engagement side of the lockup clutch 26 is continued. (T in FIG. 21₂Time) As described above, when the driving of the engine 10 by the operation of the first motor generator MG1 or the second motor generator MG2 is possible, it is set to the low vehicle speed side compared to the case where it is not possible. Since the downshift point is changed according to the lockup operation point and the turbine rotation speed is increased, the switching state to the engagement side of the lockup clutch is continued for a longer time, and the fuel cut state is executed for a longer time. The fuel supply amount is also reduced, and the fuel consumption is improved.
[0081]
As described above, according to the third embodiment, the shift control means 130 (SC7) for performing the downshift of the automatic transmission 16 based on the preset downshift point, and the downshift point are changed. Downshift point changing means 134 (SC6), and the downshift point changing means 134 changes the downshift point according to the change of the lockup operating point by the lockup operating point changing means 118 (SC4, SC9). Therefore, the automatic transmission 16 is lowered by the shift control means 130 based on the downshift point changed by the downshift point changing means 134 according to the change result of the lockup action point by the lockup action point changing means 118. Since the shift is executed, for example, the lock-up operating point changing means 118 is operated on the low vehicle speed side, that is, the When the lockup operating point is changed to the side where the switching state to the engagement side of the clutch is continued for a longer time, the downshift is executed so that the switching state to the engagement side is continued. Turbine rotation speed N_T(Similarly, engine speed N_EAlso) is raised. As a result, the fuel supply suppression time to the engine 10 becomes longer and the fuel consumption improves.
[0082]
Further, according to the third embodiment, the downshift point changing unit 134 changes the downshift point only when the fuel supply amount suppressing unit 102 can suppress the fuel supply to the engine 10. When the fuel supply cannot be suppressed, the downshift point is not changed. For example, the downshift point is changed according to the lockup operation point set at the high vehicle speed side and As a result of downshifting being performed, it is possible to avoid a possibility of a greater shift shock compared to downshifting at a low engine speed, thereby improving drivability.
[0083]
Although the first, second, and third embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be applied to other modes.
[0084]
For example, in the first embodiment described above, the fuel supply to the engine 10 shown as an example of the fuel supply amount suppression operation for reducing the fuel supply amount to the engine 10 by the fuel supply amount suppression means 102 is completely stopped. Instead of the fuel cut operation to be performed, a fuel supply control operation that reduces the fuel supply amount than usual may be used.
[0085]
Further, in the first embodiment described above, the fuel cut region in which the predetermined engine speed changed by the fuel cut region changing means 110 executed in SA3 is determined with respect to the high engine speed side (normal time). Although the setting was made only on the low rotation side, more stages may be suitably set. In this case, the lock-up operation point may be suitably set by the lock-up operation point changing means 118 executed at SA4 according to each fuel cut region.
[0086]
In the second embodiment described above, the fuel reduction line changed by the fuel reduction line changing means 112 executed in SB3 is, for example, as shown in FIG. Although there are two stages on the low rotation side, it may be suitably set so as to be more stages or continuous. In this case, the lockup operation point may be suitably set by the lockup operation point changing means 118 executed in SB4 in accordance with the respective fuel reduction lines.
[0087]
In the first, second, and third embodiments described above, the torque converter 14 provided with the lockup clutch 26 is used as the fluid transmission device. However, a fluid coupling having no torque amplification action is used. May be.
[0088]
Further, the engine 10 of the first, second, and third embodiments described above is an internal combustion engine such as a gasoline engine or a diesel engine, and it is sufficient that at least the engine is provided as a driving power source for traveling. The present invention can also be applied to a vehicle in which the exhaust turbine supercharger 54 provided in the intake pipe 50 and the exhaust pipe 52 is not provided. The rotational drive device that is operatively connected to the engine 10 only needs to assist at least the rotation of the engine 10, and the motor generators MG1 and MG2 serving as the rotational drive device include at least one of them and include at least an electric motor. In addition to being directly connected to the engine 10, it may be indirectly connected to the engine 10 via a belt or the like.
[0089]
Further, the engine 10 of the first, second, and third embodiments described above includes a variable valve mechanism 78, and an intake valve 74 and an exhaust valve 75 as electromagnetic drive valves, that is, opening / closing control valves, are electromagnetic actuators 76. The intake valve 74 and the exhaust valve 75 are driven to open and close by an electric motor as an electric actuator, and the intake valve and the exhaust valve are synchronized with the rotation of the crankshaft. A well-known valve operating mechanism that opens and closes the valve may be provided with a variable mechanism. Further, the variable mechanism may not be provided.
[0090]
In the first, second, and third embodiments, the automatic transmission 16 is a forward five-speed transmission that is a combination of three planetary gear units 40, 42, and 44. Alternatively, the transmission may be of a type in which shifting is performed by at least one of release and engagement of the hydraulic frictional engagement device of the brake B, and the number of planetary gear units constituting the automatic transmission 16 is three. May be different numbers, or may be a forward 6-speed transmission, a forward 4-speed transmission, or the like. Further, the automatic transmission 16 may be a continuously variable transmission whose gear ratio is continuously changed steplessly.
[0091]
In the first, second, and third embodiments described above, the clutch C or the brake B that is the engagement element of the automatic transmission 16 is a hydraulic friction engagement device. For example, an electromagnetic clutch or a magnetic powder clutch may be used.
[0092]
The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram illustrating a power transmission device for a hybrid vehicle to which the present invention is applied.
2 is a diagram showing a relationship between a combination of operations of a plurality of hydraulic friction engagement devices and a shift speed established thereby in the automatic transmission of FIG. 1; FIG.
3 is a schematic configuration diagram of a power transmission device of the hybrid vehicle in FIG. 1. FIG.
4 is a diagram illustrating a variable valve mechanism provided in each cylinder of the engine of FIG. 1; FIG.
5 is a diagram illustrating a configuration of an electromagnetic actuator that is provided in the variable valve mechanism of FIG. 4 and opens and closes an intake valve or an exhaust valve at a desired timing.
6 is a block diagram illustrating a main part of an input / output system of an electronic control device provided in the power transmission device of FIG. 1;
7 is a view showing a relationship between an engine throttle valve opening and an accelerator opening in the power transmission device of FIG. 1; FIG.
8 is a diagram for explaining a shift diagram used for shift control of the automatic transmission in the power transmission device of FIG. 1; FIG.
9 is a diagram for explaining a lock-up region diagram used for control of a lock-up clutch in the power transmission device of FIG. 1; FIG.
10 is a diagram showing a shift operation device provided in the vehicle of FIG. 1; FIG.
11 is a functional block diagram illustrating a main part of a control function included in the electronic control device of FIG. 6;
12 is a time chart for explaining a fuel cut operation by the electronic control unit of FIG. 6; FIG.
13 is a setting example showing a fuel cut start rotational speed and a fuel cut return rotational speed that are set in advance based on the engine water temperature used in the fuel cut operation of the electronic control device of FIG. 6;
FIG. 14 shows a part of the vicinity of the accelerator-off region in the lock-up region diagram of FIG. 9 extracted, where the solid line is the lock-up region line and the broken line is the lock-up region region line.
FIG. 15 is a diagram illustrating a main part of the control operation of the electronic control unit of FIG. 6 which is the first embodiment, that is, the lock-up operation point is changed according to the change of the fuel cut region for the fuel cut operation when the vehicle is decelerated. It is a flowchart explaining the lockup clutch control operation | movement made like this.
16 is a time chart for explaining the lock-up clutch control operation of FIG. 15;
FIG. 17 is a relationship diagram showing a fuel injection amount with respect to an engine speed used in the fuel reduction control means of the second embodiment.
FIG. 18 shows the main part of the control operation of the electronic control device of FIG. 6 which is the second embodiment, that is, lock-up according to the change of the fuel reduction line for the operation of reducing the fuel supply amount to the engine when the vehicle is decelerating. It is a flowchart explaining the control action | operation of the lockup clutch made to change an operating point.
FIG. 19 is a time chart for explaining the lockup clutch control operation of FIG. 18;
FIG. 20 shows the main part of the control operation of the electronic control unit of FIG. 6 according to the third embodiment, that is, down according to the change of the lock-up operation point for reducing the fuel supply amount to the engine when the vehicle decelerates. 6 is a flowchart for explaining a shift control operation in which a shift point is changed.
FIG. 21 is a time chart for explaining the shift control operation of FIG. 20;
[Explanation of symbols]
10: Engine
14: Torque converter (fluid transmission)
16: Automatic transmission
26: Lock-up clutch
102: Fuel supply amount suppression means
108: Fuel supply set amount changing means
114: Lock-up clutch control means
118: Lock-up operating point changing means
122: Drive assist means
124: Drive assist availability determination means
130: Shift control means
134: Downshift point changing means
MG1, MG2: Motor generator (rotary drive device)

Claims (8)

A lockup clutch control device for a vehicle, comprising: an engine that operates by combustion of fuel; a rotary drive device that is operatively connected to the engine; and a fluid transmission device with a lockup clutch,
A fuel supply amount suppression means for suppressing fuel supply to the engine based on a relationship of a fuel supply amount with respect to a preset engine rotation speed when it is determined that the accelerator or the throttle is fully closed while the vehicle is decelerating;
Fuel supply set amount changing means for changing the relationship of the fuel supply amount to the engine speed;
Lockup clutch control means for switching the engagement state of the lockup clutch based on a preset lockup operating point;
Lock-up operating point changing means for changing the lock-up operating point when the accelerator or throttle is determined to be fully closed in accordance with the change in the relationship of the fuel supply amount with respect to the engine rotation speed by the fuel supply set amount changing means; ,
Drive assist means for operating the rotational drive device to assist the engine rotational speed;
Drive assist enable / disable determining means for determining whether or not the rotational speed of the engine can be assisted by the rotation assist device being operated by the drive assist means,
The relationship of the fuel supply amount with respect to the engine rotational speed is such that the fuel supply amount with respect to the engine rotational speed for reducing control of the fuel supply to the engine by the fuel supply amount suppressing means , and a line indicating the engine rotational speed and the line Increased from a point indicating a predetermined fuel supply restart speed on a line indicating the engine rotational speed in a two-dimensional coordinate with a line indicating the fuel supply amount toward a point indicating a predetermined fuel supply amount as the engine rotational speed decreases. a fuel reduced line previously set to,
The lockup operation point changing means changes the lockup operation point when the accelerator or throttle is determined to be fully closed according to the change of the fuel reduction line by the fuel supply set amount changing means,
A plurality of fuel reduction lines are set so as to be changeable by the fuel supply set amount changing means,
The fuel supply set amount changing means, when it is determined by the drive assist enable / disable determining means that the rotation speed of the engine can be assisted by the operation of the rotational drive device, compared with the case where it is not determined. all SANYO fuel supply amount to the engine selects a fuel reduction line on the side to decrease,
The lockup operating point changing means moves the lockup operating point to a low vehicle speed side when the fuel supply set amount changing means changes the fuel reduction line to a side where the fuel supply amount with respect to the engine rotational speed is reduced. To change,
The fuel supply set amount changing means determines the relationship between the engine rotation speed and the fuel supply amount when the rotation speed is equal to or less than the fuel supply restart rotation speed when the drive assist availability determination means determines that the engine rotation speed can be assisted. The point indicating the predetermined fuel supply resumption rotational speed, which is one end of the fuel reduction line, is changed in the direction of decreasing the engine rotational speed as compared to the fuel reduction line used when it is not determined that it is possible. A vehicle lock-up clutch control device. The relationship between the fuel supply amount and the engine rotation speed is that a fuel cut region for stopping fuel supply to the engine by the fuel supply amount suppression means when the engine rotation speed is higher than a predetermined return rotation speed. Including
The lockup operating point changing means changes the lockup operating point when the accelerator or throttle is determined to be fully closed according to the change of the fuel cut region by the fuel supply set amount changing means. The vehicle lockup clutch control device according to Item 1. 3. The vehicle lockup clutch control device according to claim 2, wherein the fuel supply set amount changing means changes the fuel cut region in accordance with a determination result by the drive assist availability determining means.   The lockup operation point changing means changes the lockup operation point to a high vehicle speed side when the fuel cut region is changed to a high speed side of the engine speed by the fuel supply set amount changing means. The vehicle lock-up clutch control device according to claim 2 or 3.   The lock-up clutch control means determines that the drive assist means cannot assist the engine rotational speed by the drive assist availability determination means while the fuel supply amount suppression means stops the fuel supply to the engine. 4. The vehicle according to claim 3, wherein the lock-up clutch is not locked up until the stop of fuel supply to the engine by the fuel supply amount suppression means is stopped and fuel supply is resumed. Lock-up clutch control device.   The lockup clutch control means determines that the drive assist means cannot assist the engine rotational speed by the drive assist enable / disable determination means during the fuel supply reduction control by the fuel supply amount suppression means. Then, the lockup clutch is not locked up until the fuel supply reduction control by the fuel supply amount suppressing means is stopped and the fuel supply is resumed. Vehicle lock-up clutch control device. Shift control means for performing a downshift of the automatic transmission based on a preset downshift point;
Downshift point changing means for changing the downshift point,
The vehicle lockup clutch control device according to claim 1 or 2, wherein the downshift point changing means changes the downshift point in accordance with the change of the lockup operation point by the lockup operation point changing means.   8. The vehicle lockup clutch control device according to claim 7, wherein the downshift point changing means changes the downshift point only when fuel supply to the engine can be suppressed by the fuel supply amount suppressing means. .

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