JP5618006B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device.

  2. Description of the Related Art Conventionally, in a vehicle including a clutch that connects and disconnects a power transmission path between an engine and a drive wheel, a technique for releasing the clutch during traveling is known. For example, Patent Document 1 discloses a technology of a vehicle power transmission device that disables engine braking by opening an input clutch during coasting.

JP 2003-207036 A

  If the power transmission path is disconnected during traveling, a shock may occur due to a change in load. It is desired to be able to suppress the shock caused by the connection / disconnection of the power transmission path.

  The objective of this invention is providing the vehicle control apparatus which can suppress the shock by the connection / disconnection of a power transmission path | route.

  A vehicle control device according to the present invention includes a lockup clutch disposed in a power transmission path between an engine and a drive wheel, and a clutch that connects and disconnects the power transmission path, and the vehicle travels by connecting the power transmission path. When switching from coasting to coasting where the power transmission path is interrupted to drive the vehicle, the release start time of the lock-up clutch is different from the start of clutch release, or the drive from coasting is performed. When switching to running, at least one of different engagement start timing of the clutch and engagement start timing of the lockup clutch is performed.

  In the vehicle control device, when switching from the driving traveling to the coasting traveling, it is preferable that a release start time of the lockup clutch is earlier than a release start time of the clutch.

  In the vehicle control device, when switching from the coasting traveling to the driving traveling, it is preferable that an engagement start timing of the clutch is earlier than an engagement start timing of the lockup clutch.

  In the vehicle control device, when switching between the driving traveling and the coasting traveling, it is preferable to reduce an auxiliary machinery load of the engine.

  A vehicle control device according to the present invention includes a lockup clutch disposed in a power transmission path between an engine and driving wheels, and a clutch that connects and disconnects the power transmission path, and drives the vehicle by connecting the power transmission path. When switching from coasting to coasting where the power transmission path is cut off, the lockup clutch release start timing differs from the clutch opening start timing, or when switching from coasting to driving At least one of the engagement start time and the engagement start time of the lockup clutch is made different. According to the vehicle control device of the present invention, there is an effect that it is possible to suppress a shock due to connection / disconnection of the power transmission path.

FIG. 1 is a flowchart showing an operation of vehicle control according to the embodiment. FIG. 2 is a schematic configuration diagram of the vehicle according to the embodiment. FIG. 3 is a time chart according to the embodiment. FIG. 4 is a time chart according to the first modification of the embodiment. FIG. 5 is a time chart according to the second modification of the embodiment.

  Hereinafter, a vehicle control device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

(Embodiment)
The embodiment will be described with reference to FIGS. 1 to 3. The present embodiment relates to a vehicle control device. FIG. 1 is a flowchart showing an operation of vehicle control according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a vehicle to which the vehicle control device according to the embodiment is applied, and FIG. 3 is a time chart according to the embodiment. It is.

  In FIG. 2, the code | symbol 1 shows a vehicle. The power train of the vehicle 1 includes an engine 10 as a power source, a torque converter 20 and a continuously variable transmission 30. A continuously variable transmission (CVT) 30 that is an automatic transmission is connected to the engine 10 that is an internal combustion engine via a torque converter 20. Engine output torque (power) of the engine 10 is input from the engine output shaft 60 to the continuously variable transmission 30 via the torque converter 20 and transmitted to the drive wheels 90 via the differential gear 18 and the drive shaft 19.

  The torque converter 20 includes a pump impeller 21 connected to the engine output shaft 60 and a turbine runner 22 connected to the input shaft 70 of the continuously variable transmission 30. The pump impeller 21 is an input member to which power from the engine 10 is input in the torque converter 20. The turbine runner 22 is an output member that outputs power input from the engine 10 in the torque converter 20.

  The torque converter 20 can transmit power between the pump impeller 21 and the turbine runner 22 via a working fluid. The torque converter 20 has a lockup clutch 24. The lockup clutch 24 is a friction engagement type clutch device disposed in a power transmission path between the engine 10 and the drive wheels 90. The lock-up clutch 24 can connect the engine output shaft 60 and the input shaft 70 without using a working fluid. When the lockup clutch 24 is opened, the torque converter 20 can transmit power between the engine output shaft 60 and the input shaft 70 via the working fluid, and the lockup clutch 24 is engaged. The pump impeller 21 and the turbine runner 22 are directly connected, and power can be directly transmitted between the engine output shaft 60 and the input shaft 70 without using a working fluid.

  The continuously variable transmission 30 is, for example, a known belt type continuously variable transmission. The continuously variable transmission 30 includes a primary pulley 31 provided on the engine 10 side, a secondary pulley 32 provided on the drive wheel 90 side, a belt 33, and a clutch 36. The primary pulley 31 is connected to the input shaft 70. The secondary pulley 32 is coupled to an output shaft 80 connected to the differential gear 18. The belt 33 is stretched between the primary pulley 31 and the secondary pulley 32.

  The clutch 36 is provided on the input shaft 70 and is disposed in series with the lockup clutch 24 in the power transmission path. The clutch 36 has a function of connecting and disconnecting a power transmission path between the engine 10 and the drive wheels 90. The clutch 36 includes an engine side engagement element connected to the engine 10 side of the input shaft 70 and a drive wheel side engagement element connected to the drive wheel 90 side. The clutch 36 can connect the power transmission path between the engine 10 and the drive wheel 90 by engaging the engine side engagement element and the drive wheel side engagement element. On the other hand, when the clutch 36 is released, the power transmission path between the engine 10 and the drive wheels 90 can be interrupted. In other words, the clutch 36 functions as a switching device that switches between a state where power can be transmitted and a state where power cannot be transmitted in the power transmission path between the engine 10 and the drive wheels 90. In this specification, the clutch 36 is also referred to as “C1 clutch”.

  The hydraulic control device 40 has a function of supplying hydraulic pressure to the torque converter 20, the clutch 36, the primary pulley 31 and the secondary pulley 32. The hydraulic control device 40 changes the gear ratio of the continuously variable transmission 30 in accordance with a gear ratio change command input from the ECU 50. The hydraulic control device 40 can control the transmission ratio and the transmission speed by controlling the inflow / outflow of the hydraulic pressure to the primary pulley side actuator. By adjusting the hydraulic pressure of the primary pulley side actuator, the pulley ratio can be changed and the gear ratio can be changed steplessly. Further, the hydraulic control device 40 can control the belt clamping pressure by controlling the hydraulic pressure of the secondary pulley side actuator.

  The hydraulic control device 40 can control not only the release / engagement of the lockup clutch 24 of the torque converter 20 but also the degree of engagement of the lockup clutch 24. The hydraulic control device 40 can control the torque capacity of the lockup clutch 24 by adjusting the hydraulic pressure supplied to the lockup clutch 24. The ECU 50 can execute slip control of the lockup clutch 24 by the hydraulic control device 40 when the lockup clutch 24 is engaged or released. The ECU 50 can fully engage the lockup clutch 24 in a predetermined slip state when engaging the unlocked lockup clutch 24. Further, the ECU 50 can release the lockup clutch 24 after setting the lockup clutch 24 in a predetermined slip state when releasing the lockup clutch 24 in the fully engaged state. In the slip control, for example, the hydraulic pressure supplied to the lockup clutch 24 is controlled so that the rotational speed difference between the engine rotational speed and the rotational speed of the turbine runner 22 (turbine rotational speed) is a target value.

  The hydraulic control device 40 can control the release / engagement of the clutch 36. The hydraulic control device 40 can switch between the released state and the engaged state of the clutch 36 by controlling the hydraulic pressure supplied to the clutch 36. The hydraulic control device 40 may have a function of controlling the degree of engagement of the clutch 36.

  The continuously variable transmission 30 includes a primary pulley rotation sensor 34 that detects the rotation speed of the primary pulley 31 (primary rotation speed Nin) and a secondary pulley rotation sensor 35 that detects the rotation speed of the secondary pulley 32 (secondary rotation speed Nout). And the detected primary rotational speed Nin and secondary rotational speed Nout are output to the ECU 50.

  The vehicle 1 is provided with an ECU 50 that controls the engine 10, the continuously variable transmission 30, and the like. The ECU 50 is an electronic control unit having a computer. The ECU 50 has a function of performing comprehensive control of the engine 10, the torque converter 20, and the continuously variable transmission 30 (hydraulic control device 40). The vehicle control device 1-1 of the present embodiment includes a lockup clutch 24, a clutch 36, a hydraulic control device 40, and an ECU 50.

  The vehicle 1 is provided with an accelerator position sensor 11 that detects the amount of operation of the accelerator pedal (accelerator opening), and the detected accelerator opening is output to the ECU 50. An electronic throttle valve 13 is provided in the intake pipe 12 of the engine 10, and the electronic throttle valve 13 can be opened and closed by a throttle actuator 14. The ECU 50 drives the electronic throttle valve 13 by the throttle actuator 14 and can control the throttle opening to an arbitrary opening regardless of the accelerator opening. The vehicle 1 is provided with a throttle position sensor 15 that detects the fully closed state of the electronic throttle valve 13 and the throttle opening, and the detected throttle opening is output to the ECU 50. Reference numeral 23 denotes an exhaust pipe of the engine 10. The engine 10 is provided with an engine speed sensor 17 that detects an engine speed (engine speed), and the detected engine speed is output to the ECU 50. Further, the vehicle 1 is provided with a vehicle speed sensor 51 that detects the traveling speed of the vehicle and a shift position sensor 52 that detects the position of the shift lever operated by the driver. The shift position is output to the ECU 50.

  The navigation device 53 has a basic function of guiding the host vehicle to a predetermined destination, and includes a control unit, an operation unit, a position detection unit, a map database, a driving history recording unit, and the like. The control unit of the navigation device 53 is connected to the ECU 50, and bidirectional communication with the ECU 50 is possible. The map database of the navigation device 53 stores information (map, straight road, curve, uphill / downhill, highway, etc.) necessary for the vehicle 1 to travel. The ECU 50 can obtain information related to the traveling path such as a gradient and a curve based on the current position data acquired from the navigation device 53 and the information in the map database.

  The ECU 50 determines the fuel injection amount, the injection timing, the ignition timing, and the like based on the operating state of the engine 10 such as the engine speed, the intake air amount, and the throttle opening, and controls the injector, the spark plug, and the like. Further, the ECU 50 has a shift map, determines the gear ratio of the continuously variable transmission 30 based on the throttle opening, the vehicle speed, and the like, and the hydraulic control device 40 so as to establish the determined gear ratio. To control.

  The ECU 50 can execute coasting travel in which the vehicle 1 travels while the power transmission path between the engine 10 and the drive wheels 90 is interrupted by the clutch 36 when the vehicle 1 is decelerated or the like. The coasting traveling corresponds to traveling the vehicle 1 with the continuously variable transmission 30 being neutral. In this specification, coasting traveling is also referred to as “N coasting”. The coasting travel is executed, for example, when the accelerator opening is fully closed or when the accelerator opening is equal to or less than a predetermined opening. Not only when the accelerator opening is fully closed, but also when the accelerator opening is equal to or less than the predetermined opening, the clutch 36 is opened to shift to coasting, thereby improving fuel efficiency. For example, when the vehicle speed is high, the engine speed is high and the engine friction is large, so the running resistance is high. Accordingly, the vehicle is in a steady running or decelerating state with the accelerator pedal depressed somewhat. When shifting to coasting from this state and the clutch 36 is released, the engine speed is reduced to the idle speed, so that fuel consumption is suppressed and the running resistance (engine braking force) is reduced to improve fuel efficiency. Is possible.

  The coasting travel is not limited to deceleration, but may be executed when the vehicle 1 can travel at a constant speed with the clutch 36 engaged. In other words, the coasting traveling may be executed when the vehicle 1 does not accelerate. The coasting travel of the present embodiment may be executed at an accelerator opening that is in a driven state in which the engine 10 is driven by the driving wheels 90 or an accelerator opening that is not in a driving state in which the engine 10 drives the driving wheels 90. it can.

  In addition, on a downhill road, coasting may be performed when the vehicle 1 gently accelerates with the clutch 36 engaged. In other words, coasting travel can be appropriately executed according to the accelerator opening and travel conditions.

  The ECU 50 operates the engine 10 in an idle state during coasting traveling. In other words, during the coasting, the engine 10 consumes as much fuel as necessary to rotate independently in the idle state. When the accelerator is depressed during coasting, the ECU 50 engages the clutch 36 to return the vehicle 1 from coasting. As a result, the engine 10 can be accelerated by the power of the engine 10.

  In coasting traveling, the engine 10 is disconnected from the drive wheels 90, and the engine 10 does not act as a load on the drive wheels 90. In coasting travel, the deceleration is smaller than when traveling with the clutch 36 engaged, and the speed reduction is suppressed. As a result, the opportunity for the accelerator depressing operation for reacceleration is reduced, and fuel consumption for acceleration is suppressed.

  The coasting traveling is, for example, a traveling environment in which the fuel consumption amount when performing coasting traveling is predicted to be smaller than the fuel consumption amount when traveling with the clutch 36 engaged when traveling in the same section. It is executed under driving conditions. As an example, whether or not to shift to coasting can be determined based on the accelerator opening, the magnitude of the gradient, the vehicle speed, and the like on a gently uphill road.

  Here, a shock or vibration may occur at the time of switching between driving traveling and coasting traveling in which the vehicle 1 travels by connecting a power transmission path between the engine 10 and the drive wheels 90. For example, when the clutch 36 is disengaged to shift from driving traveling to coasting traveling, there is a case where the step of the traveling driving force is large and a shock (feeling of popping out, feeling of acceleration) occurs. Further, in the drive system between the engine 10 and the drive wheel 90, the resistance is rapidly reduced by releasing the clutch 36 from the large resistance value before the clutch 36 is released, so that vibration and shock are generated using this load changing force as an excitation force. There is a risk of doing. For example, the engine 10 that has been acting as a load until then is disconnected when the clutch 36 is released, which may cause shock or vibration.

  Further, when switching from coasting traveling to driving traveling, shock and vibration may occur. For example, when the clutch 36 is engaged to shift from coasting traveling to driving traveling, there is a risk that the step of the traveling driving force is large and a shock occurs. In addition, vibration and shock may occur due to a sudden increase in resistance due to the engagement of the clutch 36.

  The vehicle control device 1-1 of the present embodiment switches the lock-up clutch 24 and the clutch 36 at different switching start times when switching between driving traveling and coasting traveling. By making the switching start timing of the lockup clutch 24 different from the switching start timing of the clutch 36, the load on the drive wheels 90 by the engine 10 can be gradually changed to suppress the occurrence of shock.

  Here, the switching start timing in the case of switching from driving travel to coasting travel is the release start timing of each of the lockup clutch 24 and the clutch 36. The release start time is a timing at which the lock-up clutch 24 and the clutch 36 in the engaged state start to be released. The timing when the lockup clutch 24 and the clutch 36 actually start to be released can be set. In the present embodiment, the timing for outputting the opening command will be described as the opening start time. When the output of the release command is started at different timings for the lockup clutch 24 and the clutch 36, the clutch for which the output of the release command is started first is released first.

  When switching from driving traveling to coasting traveling, the load can be gradually changed and the shock can be suppressed by making the release start timing of the lockup clutch 24 different from the release start timing of the clutch 36. Note that the engagement state of the lock-up clutch 24 and the clutch 36 before the start of opening is not limited to complete engagement but may be half-engagement (slip engagement).

  In this embodiment, when switching from driving to coasting, the release start time of the lockup clutch 24 is earlier than the release start time of the clutch 36. When the lockup clutch 24 starts to be released first, the degree of engagement of the lockup clutch 24 first decreases. Thereby, the engine load with respect to the drive wheel 90 falls. That is, the engine brake is ineffective, and the driving force generated on the drive wheel 90 is between the driving force when the lockup clutch 24 and the clutch 36 are completely engaged and the driving force when the clutch 36 is released. Driving force. After that, when the clutch 36 is started to be released, the load fluctuation due to the shift to coasting is reduced. Further, since the degree of engagement of the lockup clutch 24 is reduced when the clutch 36 is released, shock and vibration are absorbed by the torque converter 20. For example, in a fluid transmission state in which the lockup clutch 24 is open, shock and vibration are easily absorbed by the working fluid.

  On the other hand, the switching start timing when switching from coasting traveling to driving traveling is the engagement starting timing of each of the lockup clutch 24 and the clutch 36. The engagement start timing is a timing at which engagement of the unlocked lockup clutch 24 and the clutch 36 is started. For example, an output start timing of an engagement command to the hydraulic control device 40, a change in supply hydraulic pressure based on the engagement command The start timing, the timing when the lockup clutch 24 and the clutch 36 actually start to be engaged, and the like can be used. In the present embodiment, the timing for starting to output the engagement command will be described as the engagement start timing. When the output of the engagement command is started at different timings with respect to the lockup clutch 24 and the clutch 36, it is assumed that the clutch for which the output of the engagement command has started first starts to be engaged first.

  When switching from coasting traveling to driving traveling, by changing the engagement start timing of the lockup clutch 24 and the engagement start timing of the clutch 36, the load can be gradually changed to suppress the shock.

  In this embodiment, when switching from coasting traveling to driving traveling, the engagement start timing of the clutch 36 is earlier than the engagement start timing of the lockup clutch 24. By starting engagement of the clutch 36 in a state where the lock-up clutch 24 is released, a sudden change in load on the drive wheels 90 when the clutch 36 is switched is suppressed. Further, shock and vibration are absorbed by the torque converter 20.

  With reference to FIG. 1 and FIG. 3, the vehicle control of this embodiment is demonstrated. 3, (a) is the accelerator opening, (b) is the hydraulic pressure supplied to the lockup clutch 24 (hereinafter simply referred to as “lockup hydraulic pressure”) P_lu, and (c) is the hydraulic pressure supplied to the clutch 36 ( Hereinafter, it is simply referred to as “clutch supply hydraulic pressure.”) P_c1, (d) indicates the engine speed, (e) indicates the throttle opening, and (f) indicates the fuel cut signal.

  The control flow shown in FIG. 1 is repeatedly executed while the vehicle 1 is traveling. For example, the control flow is repeatedly executed at predetermined intervals. First, in step S1, the ECU 50 determines whether or not the accelerator opening Acc is 0% or less. As a result of the determination, if it is determined that the accelerator opening Acc is 0% or less (step S1-Y), the process proceeds to step S2, and if not (step S1-N), the process proceeds to step S11. In step S1, instead of the condition that the accelerator opening Acc is 0% or less, an affirmative determination may be made when the condition that the accelerator opening Acc is a predetermined opening or less is satisfied. The predetermined opening can be determined, for example, within a range of an accelerator opening Acc at which the vehicle 1 travels at a reduced speed.

  In step S2, the ECU 50 determines whether or not the N coasting control flag flagN is 1. The N coasting control flag flagN is set to 1 during the coasting running. The N coasting control flag flagN is set to 1 when the coasting traveling execution condition is satisfied during driving traveling, and is set to 0 when the coasting traveling is finished and the driving traveling is started. As a result of the determination in step S2, if it is determined that the N coasting control flag flagN is 1 (step S2-Y), the process proceeds to step S4. If not (step S2-N), the process proceeds to step S3.

  In step S <b> 3, the ECU 50 sets an initial value for transition from driving to coasting. The ECU 50 sets the N coasting control flag flagN to 1 and sets the N coasting transition Mode to 1. The mode of N coasting transition changes as the transition operation to coasting progresses. Mode is set to 1 until the lockup clutch 24 is released. When the release of the lockup clutch 24 is completed, the Mode is changed to 2, and the clutch 36 is released. When the release of the clutch 36 is completed, Mode is set to 3 and the transition to coasting is completed. When step S3 is executed, the control flow ends.

  In step S4, the ECU 50 executes control for each mode of N coasting transition. When the N coasting mode is 1, the process proceeds to step S5. If Mode is 2, the process proceeds to step S8. If the Mode is 3, the control flow ends.

  In step S5, the ECU 50 performs an operation of releasing the lockup clutch 24. The ECU 50 outputs a release command LU_OFF for the lockup clutch 24 to the hydraulic control device 40. The hydraulic control device 40 decreases the lockup supply hydraulic pressure P_lu based on the release command LU_OFF. The reduction speed of the lockup supply hydraulic pressure P_lu at this time can be a predetermined speed. In FIG. 3, the lock-up clutch 24 is released from time t1 to time t2. When step S5 is executed, the process proceeds to step S6.

  In step S6, the ECU 50 determines whether or not the release operation of the lockup clutch 24 has been completed. The ECU 50 can make the determination in step S6 based on, for example, the rotational speed difference between the engine rotational speed and the turbine rotational speed. As a result of the determination in step S6, if it is determined that the unlocking operation of the lockup clutch 24 has been completed (step S6-Y), the process proceeds to step S7. If not (step S6-N), this control flow is finish.

  In step S7, the ECU 50 sets the mode of N coasting transition to 2. When step S7 is executed, this control flow ends.

  In step S8, the ECU 50 performs an operation of releasing the clutch 36 (C1 clutch). The ECU 50 outputs a release command C1_OFF for the clutch 36 to the hydraulic control device 40. The hydraulic control device 40 decreases the clutch supply hydraulic pressure P_c1 based on the release command C1_OFF. At this time, the reduction speed of the clutch supply hydraulic pressure P_c1 can be set to a predetermined speed. In FIG. 3, the clutch 36 is released from time t2 to time t3. When step S8 is executed, the process proceeds to step S9.

  In step S9, the ECU 50 determines whether or not the release operation of the clutch 36 has been completed. As a result of the determination in step S9, if it is determined that the operation of disengaging the clutch 36 has been completed (step S9-Y), the process proceeds to step S10. If not (step S9-N), this control flow ends. .

  In step S10, the ECU 50 sets the N coasting mode to 3 and sets the D range control flag flagD to 0. The D range control flag flagD is set to 1 during execution of driving travel. The D range control flag flagD is set to 0 when coasting traveling is started, and is set to 1 when the coasting traveling is finished and the driving traveling is started. Note that coasting travel is not limited to the D range, and can be executed when another forward travel range is selected. When returning to drive travel according to the accelerator opening Acc during coasting travel, the drive travel in the travel state corresponding to each range is resumed. When step S10 is executed, this control flow ends.

  In step S11, the ECU 50 determines whether or not the D range control flag flagD is 1. As a result of the determination, if it is determined that the D range control flag flagD is 1 (step S11-Y), the process proceeds to step S13, and if not (step S11-N), the process proceeds to step S12.

  In step S12, the ECU 50 sets the D range control flag flagD to 1 and sets the N coasting return Mode to 3. The mode of N coasting return changes according to the progress of the return operation from coasting traveling to driving traveling. In the present embodiment, the mode of N coasting return is set to 3 until the rotational speed synchronization control described later is completed. When the rotation speed synchronization control is completed, Mode is changed to 2, and the clutch 36 is engaged. When the engagement of the clutch 36 is completed, Mode is set to 1 and the lockup clutch 24 is engaged. When the engagement of the lockup clutch 24 is completed, Mode is set to 0 and the return from coasting is completed. When step S12 is executed, this control flow ends.

  In step S13, the ECU 50 executes control for each mode of N coasting return. If the N coasting return Mode is 3, the process proceeds to step S14. If Mode is 2, the process proceeds to step S17. If Mode is 1, the process proceeds to step S20. If the Mode is 0, the control flow ends.

  In step S14, the ECU 50 performs a rotation speed synchronization operation. The rotational speed synchronization operation is rotational speed synchronization control that synchronizes the engine rotational speed Ne with the primary rotational speed Nin. In the rotation speed synchronization operation, for example, the engine rotation speed Ne is increased by increasing the fuel injection amount of the engine 10 to approach the primary rotation speed Nin. In FIG. 3, the rotational speed synchronization control is performed from time t4 to time t5. When step S14 is executed, the process proceeds to step S15.

  In step S15, the ECU 50 determines whether or not the rotation speed synchronization is completed. The ECU 50 can make the determination in step S15 based on the differential rotation between the engine rotation speed Ne and the primary rotation speed Nin. As a result of the determination in step S15, when it is determined that the rotation speed synchronization has been completed (step S15-Y), the process proceeds to step S16. Otherwise (step S15-N), the control flow ends.

  In step S16, the ECU 50 sets the mode of N coasting return to 2. When step S16 is executed, the control flow ends.

  In step S17, the engagement operation of the clutch 36 is performed by the ECU 50. The ECU 50 outputs an engagement command C1_ON for the clutch 36 to the hydraulic control device 40. The hydraulic control device 40 increases the clutch supply hydraulic pressure P_C1 based on the engagement command C1_ON. In FIG. 3, the clutch 36 is engaged from time t5 to time t6. When step S17 is executed, the process proceeds to step S18.

  In step S18, the ECU 50 determines whether or not the engagement of the clutch 36 has been completed. The ECU 50 can make the determination in step S18 based on, for example, the rotational speed difference between the turbine rotational speed and the primary rotational speed Nin. As a result of the determination in step S18, if it is determined that the engagement of the clutch 36 has been completed (step S18-Y), the process proceeds to step S19, and if not (step S18-N), this control flow ends. .

  In step S19, the ECU 50 sets the N coasting return mode to 1. When step S19 is executed, the control flow ends.

  In step S20, the engagement operation of the lockup clutch 24 is performed by the ECU 50. The ECU 50 outputs an engagement command LU_ON for the lockup clutch 24 to the hydraulic control device 40. The hydraulic control device 40 increases the lockup supply hydraulic pressure P_lu based on the engagement command LU_ON. In FIG. 3, the lock-up clutch 24 is engaged from time t6 to time t7. When step S20 is executed, the process proceeds to step S21.

  In step S21, the ECU 50 determines whether or not the engagement of the lockup clutch 24 has been completed. The ECU 50 can make the determination in step S21 based on the rotational speed difference between the engine rotational speed Ne and the turbine rotational speed. As a result of the determination in step S21, if it is determined that the engagement of the lockup clutch 24 has been completed (step S21-Y), the process proceeds to step S22, and if not (step S21-N), this control flow is finish.

  In step S22, the ECU 50 sets the N coasting return mode to 0 and the N coasting control flag flagN to 0. When step S22 is executed, the control flow ends.

  According to the vehicle control device 1-1 of the present embodiment, when switching from driving to coasting, the lockup clutch 24 is first released and then the clutch 36 is released, so that the load from the engine 10 is gradually increased. Reduce. As a result, it is possible to suppress a sudden change in the load when the power transmission path between the engine 10 and the drive wheels 90 is interrupted, thereby reducing the shock. In this embodiment, the release operation of the clutch 36 is started after the release of the lockup clutch 24 is completed, but the present invention is not limited to this. The release start timing of the clutch 36 may be after the start of the release operation of the lockup clutch 24 and before the release of the lockup clutch 24 is completed. For example, the period before the unlocking of the lockup clutch 24 is completed may be somewhat overlapped with the period after the start of the clutch 36 releasing operation.

  Further, according to the vehicle control device 1-1 of the present embodiment, when switching from coasting traveling to driving traveling, the clutch 36 and the lockup clutch 24 are engaged after the engine speed Ne is synchronized with the primary rotational speed Nin. Is done. By the rotation speed synchronization control, a shock when the clutch 36 is engaged is suppressed. Further, since the lockup clutch 24 is engaged after the clutch 36 is engaged, a sudden change in load when the power transmission path between the engine 10 and the drive wheels 90 is connected is suppressed. Therefore, the load by the engine 10 can be gradually applied to the drive wheels 90, and the shock can be suppressed.

  In the present embodiment, the engagement operation of the clutch 36 is started after the rotation speed synchronization control is completed, and the engagement operation of the lockup clutch 24 is started after the engagement of the clutch 36 is completed. Each timing is not limited to this. For example, the engagement operation start timing of the clutch 36 may be after the start of the rotation speed synchronization control and before the completion of the rotation speed synchronization control. For example, the period before the completion of the rotation speed synchronization control and the period after the start of the engagement operation of the clutch 36 may be somewhat overlapped. Further, the engagement start timing of the lockup clutch 24 may be after the start of the engagement operation of the clutch 36 and before the completion of the engagement operation. For example, the period before the completion of engagement of the clutch 36 and the period after the start of the engagement operation of the lockup clutch 24 may be somewhat overlapped.

  In the present embodiment, the transmission of the vehicle 1 is the continuously variable transmission 30, but the present invention is not limited to this. Instead of the continuously variable transmission 30, a stepped automatic transmission may be mounted, or other known transmissions and transmission mechanisms may be mounted.

  In the present embodiment, the clutch 36 that connects and disconnects the power transmission path between the engine 10 and the drive wheels 90 is provided on the input shaft 70, but the arrangement of the clutch 36 is not limited to this. For example, the clutch 36 may be disposed in another part of the power transmission path.

  In the present embodiment, the fuel injection of the engine 10 is continued and the engine 10 is operated during coasting, but the present invention is not limited to this. For example, the fuel injection of the engine 10 may be stopped during coasting.

  The clutch that is switched between the engaged state and the released state when switching between driving traveling and coasting traveling is not limited to the clutch 36 and the lockup clutch 24. Furthermore, another clutch device may be engaged or released when switching between driving traveling and coasting traveling. The other clutch device is disposed in the power transmission path between the engine 10 and the drive wheel 90, and is preferably switched to a switching start timing different from the switching start timing of either the clutch 36 or the lockup clutch 24. .

[First Modification of Embodiment]
A first modification of the embodiment will be described. In the present modification, rapid control is executed that can advance the completion timing of the transition from coasting to driving. Specifically, the engagement operation of the clutch 36 and the engagement operation of the lockup clutch 24 are performed almost simultaneously at the time of transition from coasting traveling to driving traveling. Since the clutch 36 and the lockup clutch 24 are simultaneously engaged after the rotation speed synchronization control is completed, it is possible to increase the response to the shift to the driving travel.

  FIG. 4 is a time chart of control according to the first modification. In the present modification, when the rotation speed synchronization control is completed at time t5, the engagement operation of the clutch 36 and the engagement operation of the lockup clutch 24 are performed in parallel. The start timing of the engagement operation of the clutch 36 and the start timing of the engagement operation of the lockup clutch 24 may be simultaneous, and the start timing of the engagement operation of the clutch 36 is the start of the engagement operation of the lockup clutch 24. It may be earlier than the time. Note that the start timing of the engagement operation of the clutch 36 and the lockup clutch 24 may be determined so that the engagement completion timing of the clutch 36 and the engagement completion timing of the lockup clutch 24 are the same. Note that at least one of the engagement operation of the clutch 36 and the engagement operation of the lockup clutch 24 may be started before the completion of the rotation speed synchronization control.

[Second Modification of Embodiment]
A second modification of the embodiment will be described. In the present modification, as the rapid control, the rotation speed synchronization control and the engagement operation of the clutch 36 are simultaneously performed at the time of transition from coasting traveling to driving traveling. FIG. 5 is a time chart of control according to the second modification.

  In this modification, when the accelerator is turned on at time t4, the rotation speed synchronization control and the engagement operation of the clutch 36 are performed in parallel. The start time of the rotation speed synchronization control and the start time of the engagement operation of the clutch 36 may be simultaneous, or the start time of the rotation speed synchronization control may be earlier than the start time of the engagement operation of the clutch 36. The start time of the rotation speed synchronization control and the start time of the engagement operation of the clutch 36 may be determined so that the completion time of the rotation speed synchronization control and the engagement completion time of the clutch 36 are the same.

  When the rotation speed synchronization control and the engagement of the clutch 36 are completed, the engagement operation of the lockup clutch 24 is started. Note that the engagement operation of the lockup clutch 24 may be started earlier than at least one of the completion of the rotation speed synchronization control and the completion of the engagement of the clutch 36.

[Third Modification of Embodiment]
A third modification of the embodiment will be described. In the present modification, as the rapid control, the rotational speed synchronization control and the engagement operation of the lockup clutch 24 are simultaneously performed at the time of transition from coasting traveling to driving traveling.

  In this modification, when the accelerator is turned on during coasting, the rotation speed synchronization control and the engagement operation of the lockup clutch 24 are performed in parallel. The start time of the rotation speed synchronization control and the start time of the engagement operation of the lockup clutch 24 may be simultaneous, and the start time of the rotation speed synchronization control is earlier than the start time of the engagement operation of the lockup clutch 24. May be. The start timing of the rotation speed synchronization control and the start timing of the engagement operation of the lockup clutch 24 are determined so that the completion time of the rotation speed synchronization control and the engagement completion time of the lockup clutch 24 are the same. Also good.

  In a state where the clutch 36 is released, the difference in rotational speed between the turbine rotational speed and the engine rotational speed Ne is small, and the driving wheels 90 are disconnected from the turbine runner 22 so that the load is small. Therefore, the engagement operation of the lock-up clutch 24 can be completed in a shorter time than when the clutch 36 is engaged.

  When the rotation speed synchronization control and the engagement of the lockup clutch 24 are completed, the engagement operation of the clutch 36 is started. The engagement operation of the clutch 36 may be started earlier than at least one of the completion of the rotation speed synchronization control and the completion of the engagement of the lockup clutch 24.

[Fourth Modification of Embodiment]
A fourth modification of the embodiment will be described. In the present modification, as the rapid control, all of the rotation speed synchronization control, the engagement operation of the lockup clutch 24, and the engagement operation of the clutch 36 are simultaneously performed at the time of transition from coasting traveling to driving traveling.

  In this modification, when the accelerator is turned on during coasting, the rotational speed synchronization control, the engagement operation of the lockup clutch 24, and the engagement operation of the clutch 36 are performed in parallel. The start timing of the rotational speed synchronization control, the start timing of the engagement operation of the lockup clutch 24, and the start timing of the engagement operation of the clutch 36 may be the same or different as appropriate. It should be noted that the rotation speed synchronization control start timing and the lockup clutch 24 engagement time are set so that the rotation speed synchronization control completion timing, the lockup clutch 24 engagement completion timing, and the clutch 36 engagement completion timing are the same. The operation start time and the engagement operation start time of the clutch 36 may be determined.

[Fifth Modification of Embodiment]
A fifth modification of the embodiment will be described. By selectively executing the rapid control from the first modification to the fourth modification, the responsiveness of the transition from coasting traveling to driving traveling can be made variable. For example, the response required by the driver may be estimated based on the accelerator opening and the accelerator operation speed when the accelerator is turned on, and it may be determined which rapid control is performed so as to realize the response. . It can be estimated that the driver is demanding higher responsiveness as the accelerator opening is larger and the accelerator operation speed is larger. The drivability can be improved by selecting the rapid control to be executed according to the required responsiveness.

  Note that which rapid control response is high may be ranked in advance based on the result of a matching experiment or the like. According to this modification, both suppression of shock and responsiveness can be achieved. It should be noted that the rotational speed synchronization control can be omitted in the embodiment and each modification.

[Sixth Modification of Embodiment]
A sixth modification of the embodiment will be described. In the above-described embodiment and each modification, when switching between coasting traveling and driving traveling, the auxiliary machinery load of the engine 10 may be reduced. The auxiliary load is a disturbance that changes the engine shaft torque, and may increase the shock. By reducing the load on the auxiliary machine, the load on the engine 10 is reduced, so that a shock when the power transmission path between the engine 10 and the drive wheels 90 is connected or cut off is suppressed. Examples of the auxiliary machine for the engine 10 include an air conditioner compressor and an alternator.

  To reduce the auxiliary load, reduce the auxiliary load at the time of switching between coasting and driving from the auxiliary load before the start of switching, and the auxiliary load at the time of switching from a predetermined allowable load. Also includes a small load.

  For example, if the load control of the auxiliary machine is forcibly stopped in advance when shifting from coasting traveling to driving traveling to a light load or no load state, the shock at the time of connecting the power transmission path can be reduced. Further, if the load control of the auxiliary machine is forcibly stopped in advance when shifting from the driving traveling to the coasting traveling to a light load or no load state, a shock at the time of cutting off the power transmission path can be reduced. The load control of the auxiliary machine can be resumed after the switching between coasting and driving is completed.

[Seventh Modification of Embodiment]
A seventh modification of the embodiment will be described. You may make it perform rotation speed synchronous control before the return determination from coasting driving | running | working is made. By performing the rotational speed synchronization control in advance, it is possible to improve the responsiveness of shifting from coasting traveling to driving traveling. For example, when it is determined that coasting travel is performed when the accelerator opening is equal to or less than a predetermined opening, execution determination of the rotation speed synchronization control may be performed in the region of the accelerator opening less than the predetermined opening during coasting traveling. A threshold (for example, 3%) less than a predetermined opening (for example, 5%) is set, and the rotation speed synchronization control can be executed when an accelerator opening that is equal to or greater than the threshold is detected.

  In addition to the accelerator opening, it may be determined whether to execute the rotational speed synchronization control based on the accelerator operation speed. For example, even when the accelerator opening degree equal to or greater than the threshold value is detected, the rotation speed synchronization control may not be executed if the accelerator operation speed is low. Further, the threshold value may be variable based on the accelerator operation speed. For example, the threshold value when the accelerator operation speed is high may be an opening smaller than the threshold value when the accelerator operation speed is low.

  The contents disclosed in the above embodiment and each modification can be executed in appropriate combination.

1-1 Vehicle Control Device 1 Vehicle 10 Engine 20 Torque Converter 24 Lockup Clutch 30 Continuously Variable Transmission 36 Clutch 50 ECU
90 Driving wheel
flagD D range control flag
flagN N coasting control flag
P_lu Lock-up supply hydraulic pressure
P_C1 Clutch supply hydraulic pressure

Claims (4)

A lock-up clutch disposed in the power transmission path between the engine and the drive wheel;
A clutch for connecting / disconnecting the power transmission path, and the lockup clutch when switching from driving driving for connecting the power transmission path to traveling for driving the vehicle while blocking the power transmission path for driving the vehicle. The clutch release start timing is different from the clutch release start timing, or the clutch engagement start timing and the lockup clutch engagement start timing are different when switching from coasting to drive driving. A vehicle control device that performs at least one of the above. The vehicle control device according to claim 1, wherein when the driving travel is switched to the coasting travel, the release start time of the lockup clutch is earlier than the release start time of the clutch. 4. The vehicle control device according to claim 1, wherein, when the coasting traveling is switched to the driving traveling, the engagement start timing of the clutch is earlier than the engagement start timing of the lockup clutch. The vehicle control device according to claim 1, wherein when switching between the driving traveling and the coasting traveling, an auxiliary load on the engine is reduced.

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