JP2012072740A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control system which can properly start an internal combustion engine while the vehicle is running.SOLUTION: The vehicle control system 1 includes the internal combustion engine 4, an engaging device 10, and a control device 8 to execute an engagement control to control the engaging device 10 into such a condition as engaged by an engaging force no less than a first engaging force in case the engine speed of the internal combustion engine 4 is at or over the preset engine stopping revolving speed when the internal combustion engine 4 is put in the non-operational condition while the vehicle 2 is running, and to execute a disengage control, in case the engine speed of the internal combustion engine 4 is below the engine stopping revolving speed, whereby the engaging device 10 is controlled into such a condition as disengaged by a force at or below a second engaging force which is smaller than the first engaging force, and accordingly, the internal combustion engine 4 can be properly started while the vehicle 2 is running.

Description

  The present invention relates to a vehicle control system.

  As a conventional vehicle control system, for example, Patent Document 1 discloses that a fuel cut is performed according to the vehicle's decelerating running state, and a necessary amount of fuel is used to eliminate an overoxygen state of the catalyst when returning from the fuel cut. An automatic stop and start device for an engine for injection is disclosed. The engine automatic stop / start device cuts off the torque transmission between the wheel and the engine simultaneously with the end of the return fuel injection from the fuel cut when it is determined that the idle stop is possible after the deceleration fuel cut. This prevents the exhaust from deteriorating when the engine is restarted after an idle stop.

JP-A-2005-075228

  By the way, the engine automatic stop and start device described in Patent Document 1 as described above has room for further improvement in order to start the internal combustion engine more appropriately while the vehicle is running, for example.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control system that can properly start an internal combustion engine while the vehicle is running.

  In order to achieve the above object, a vehicle control system according to the present invention includes an operating state in which power is applied to drive wheels of a vehicle and a non-operating state in which generation of the power is stopped while the vehicle is traveling. The internal combustion engine that can be switched, and the internal combustion engine side rotation member and the drive wheel side rotation member can be switched between a state in which power can be transmitted and a state in which the engagement is released. An engagement device capable of adjusting an engagement force for engaging the engine-side rotation member and the drive wheel-side rotation member; and the internal combustion engine when the internal combustion engine is inactivated during the traveling of the vehicle. When the engine rotation speed of the engine is equal to or higher than a preset engine stop rotation speed, an engagement control is performed to control the engagement device to the engaged state with an engagement force equal to or higher than a first engagement force, The engine speed of the internal combustion engine A control device that performs release control for controlling the engagement device to a state in which the engagement is released with an engagement force equal to or smaller than a second engagement force that is smaller than the first engagement force when the rotation speed is lower than the rotation speed. It is characterized by.

  In the vehicle control system, when the internal combustion engine is started after the internal combustion engine is deactivated while the vehicle is running, the engine rotational speed of the internal combustion engine is set to the engine stop rotation. When the engine speed is equal to or higher than the speed, the internal combustion engine is restarted by supplying fuel to the internal combustion engine after executing the engagement control, and the engine rotation speed of the internal combustion engine is less than the engine stop rotation speed After executing the release control, the internal combustion engine can be restarted by cranking by an electric motor and supply of fuel to the internal combustion engine.

  In the vehicle control system, the control device executes engagement force adjustment control for adjusting the engagement force during the engagement control, and sets the engine rotation speed of the internal combustion engine in accordance with the engine stop rotation speed. It can be set as a target rotational speed.

  In the vehicle control system, the control device may reduce the engagement force relatively when the vehicle speed of the vehicle is relatively high during the engagement force adjustment control, and the vehicle speed of the vehicle is relative. The engagement force can be relatively increased when the pressure is low.

  Further, in the vehicle control system, the control device prohibits the engagement force adjustment control during execution of the engine brake increase control for relatively increasing the engine brake using the rotation resistance of the internal combustion engine. Can do.

  Further, in the vehicle control system, the control device prohibits the engagement force adjustment control when the deceleration of the vehicle due to a factor other than engine braking using the rotational resistance of the internal combustion engine is relatively large. The engagement force can be relatively increased and held.

  In the vehicle control system, the control device may change the engine stop rotational speed based on the temperature of oil supplied to the internal combustion engine.

  In the vehicle control system, the control device may change the engine stop rotational speed based on a temperature of a cooling medium that cools the internal combustion engine.

  In the vehicle control system, the control device may change the engine stop rotational speed based on an intake air density of the internal combustion engine.

  In the vehicle control system, the control device may change the engine stop rotational speed based on a fuel property of fuel supplied to a combustion chamber of the internal combustion engine.

  Moreover, in the said vehicle control system, the said control apparatus shall change the said engine stop rotational speed based on the temperature of the oil supplied to the power transmission device containing the said engagement apparatus.

  In the vehicle control system, the control device may change the engine stop rotational speed based on a change speed of an engine rotational speed of the internal combustion engine.

  The vehicle control system according to the present invention has an effect that the internal combustion engine can be started properly while the vehicle is running.

FIG. 1 is a schematic configuration diagram of a vehicle control system according to the first embodiment. FIG. 2 is a time chart for explaining an example of the engagement control. FIG. 3 is a time chart for explaining an example of release control. FIG. 4 is a flowchart illustrating an example of control by the ECU. FIG. 5 is a flowchart illustrating an example of control by the ECU of the vehicle control system according to the second embodiment. FIG. 6 is a diagram showing an example of an engine torque map. FIG. 7 is a diagram showing an example of a clutch hydraulic pressure map. FIG. 8 is a diagram showing an example of a clutch hydraulic pressure map according to a modification. FIG. 9 is a time chart illustrating an example of control by the ECU of the vehicle control system according to the third embodiment.

  Embodiments according to the present invention will be described below 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 replaced by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of the vehicle control system according to the first embodiment, FIG. 2 is a time chart for explaining an example of engagement control, FIG. 3 is a time chart for explaining an example of release control, and FIG. It is a flowchart explaining an example of control by ECU.

  As shown in FIG. 1, the vehicle control system 1 of the present embodiment is applied to a vehicle 2, and an engine 4 as an internal combustion engine that generates power for driving the drive wheels 3, and the power generated by the engine 4. A vehicle 2 including a power transmission device 5 that forms a power transmission system for transmitting to the drive wheels 3, a brake device 6 as a braking device for the vehicle 2, a state detection device 7 that detects the state of the vehicle 2, and a vehicle control system 1. ECU8 as a control apparatus which controls each part of these.

  The engine 4 is a driving source (prime mover) for driving the vehicle 2. The engine 4 generates power that acts on the drive wheels 3 of the vehicle 2 as the fuel burns. The engine 4 can switch between an operating state and a non-operating state while the vehicle 2 is traveling. Here, the operating state of the engine 4 (the state in which the engine 4 is operated) is a state in which power to be applied to the drive wheels 3 of the vehicle 2 is generated, and thermal energy generated by burning fuel in the combustion chamber is torqued. In this state, the output is in the form of mechanical energy. On the other hand, the non-operating state of the engine 4, that is, the state where the operation of the engine 4 is stopped is a state where the generation of power is stopped, the supply of fuel to the combustion chamber is stopped (fuel cut), and the combustion chamber In this state, the fuel is not burned and no mechanical energy such as torque is output.

  The power transmission device 5 includes a torque converter 9 which is a fluid transmission device with a lock-up clutch, a transmission 11 including an input clutch 10 as an engagement device, a differential gear 12 coupled to the transmission 11, a differential A drive shaft 13 that connects the gear 12 and the drive wheel 3 is included.

  Various clutches can be used as the input clutch 10, and the engaged state in which the rotating member 10 a on the engine 4 side and the rotating member 10 b on the drive wheel 3 side are engaged so as to be able to transmit power and the engagement is released. It can be switched to the released state. When the input clutch 10 is in the released state, the engine 4 and the drive wheel 3 can be disconnected and the power transmission between the engine 4 and the drive wheel 3 can be cut off. Here, the rotation member 10a on the engine 4 side corresponds to the output shaft of the torque converter 9, and the rotation member 10b on the drive wheel 3 side is the input shaft of the main body of the transmission 11 (the transmission mechanism that actually performs a shift). It corresponds to. That is, in the power transmission device 5, the output shaft of the torque converter 9 and the input shaft of the main body of the transmission 11 are connected via the input clutch 10.

  Further, the input clutch 10 is capable of adjusting the engagement force for engaging the rotating member 10a on the engine 4 side and the rotating member 10b on the drive wheel 3 side. When the engagement force is 0, the input clutch 10 is in a completely released state in which the engagement is completely released, and is in a fully engaged state through a half-engaged state (slip state) as the engagement force increases. The transmission 11 includes, for example, a manual transmission (MT), a stepped automatic transmission (AT), a continuously variable automatic transmission (CVT), a multimode manual transmission (MMT), a sequential manual transmission (SMT), dual Various configurations such as a clutch transmission (DCT) can be used.

  The power generated by the engine 4 is input to the input clutch 10 of the transmission 11 through the torque converter 9, and is shifted by the transmission 11 at a predetermined gear ratio, and is driven through the differential gear 12 and the drive shaft 13. It is transmitted to the wheel 3. As a result, the driving force [N] is generated on the contact surface with the road surface of the driving wheel 3, and the vehicle 2 can travel by this.

  The brake device 6 applies a braking force to the wheels including the drive wheels 3. As a result, the vehicle 2 can be braked by the braking force [N] generated on the contact surface with the road surface of the drive wheel 3.

  The state detection device 7 is electrically connected to the ECU 8 and can exchange information such as a detection signal, a drive signal, and a control command with each other. The state detection device 7 includes, for example, an engine speed sensor 70 that detects the engine speed, an accelerator opening sensor 71 that detects an accelerator opening that is an accelerator pedal operation amount (accelerator operation amount) by the driver, and a driver's operation. A brake sensor 72 that detects the brake pedal operation amount, for example, master cylinder pressure and the like, detects a braking force, an input shaft rotational speed sensor 73 that detects an input shaft rotational speed of the transmission 11, and an output shaft rotational speed of the transmission 11. An output shaft rotation speed sensor 74 that detects the engine oil temperature sensor 75 that detects the temperature of the engine oil supplied to the engine 4 and used in the engine 4, and detects the temperature of engine coolant that serves as a cooling medium for cooling the engine 4 Cooling water temperature sensor 76, intake air amount, intake air temperature, intake air density, etc. An intake sensor 77 for detecting information on the fuel, a fuel property sensor 78 for detecting the fuel property of the fuel supplied to the combustion chamber of the engine 4, the power transmission device 5 etc. supplied to the power transmission device 5 etc. Various sensors, detection devices and the like provided in each part of the vehicle 2 such as the TM oil temperature sensor 79 for detecting temperature are included.

  The ECU 8 is an electronic circuit mainly composed of a known microcomputer including a CPU, a ROM, a RAM, and an interface. The ECU 8 controls the power transmission device 5 including the engine 4, the transmission 11 and the like, the brake device 6 and the like. Here, the power transmission device 5 and the brake device 6 including the transmission 11 and the like are hydraulic devices that are operated by the pressure (hydraulic pressure) of hydraulic oil as a medium, and the ECU 8 includes a TM hydraulic control device 14 and a brake, respectively. The operations of the transmission 11 and the brake device 6 are controlled via the hydraulic control device 15 and the like, and for example, the transmission operation of the transmission 11 and the engagement / release operation of the input clutch 10 are controlled. The ECU 8 receives electrical signals corresponding to detection results detected from various sensors, and outputs drive signals to these units in accordance with the input detection results to control their drive.

  For example, during normal operation, the ECU 8 controls the throttle device 16 of the engine 4 based on the accelerator opening, the vehicle speed, etc., adjusts the throttle opening of the intake passage 17, and adjusts the intake air amount, The fuel injection amount is controlled in accordance with the change, and the output of the engine 4 is controlled by adjusting the amount of the air-fuel mixture filled in the combustion chamber. Further, the ECU 8 controls the TM hydraulic control device 14 based on the accelerator opening, the vehicle speed, etc., and controls the operating state of the input clutch 10 and the gear ratio of the transmission 11.

  Then, the ECU 8 can start or stop the operation of the engine 4 while the vehicle 2 is traveling, and can switch between the operation state and the non-operation state of the engine 4. This vehicle control system 1 is typically used when the vehicle 2 is traveling under predetermined conditions, for example, when the vehicle 2 is decelerated due to coasting with the accelerator off, or when the engine speed is equal to or higher than the predetermined speed. In addition, the ECU 8 executes fuel cut control for stopping the supply of fuel to the combustion chamber of the engine 4 so that the operation of the engine 4 is stopped, and the vehicle 2 is coasted (coast down), so-called eco-run state. It is possible to shift to the control as described above, which makes it possible to improve fuel efficiency. The ECU 8 can return the vehicle 2 to the normal traveling that travels again by the power generated by the engine 4 by restarting the engine 4 under a predetermined condition, for example, when the accelerator is turned on.

  By the way, in the vehicle control system 1 of the present embodiment, the engine speed (engine speed) of the engine 4 is preset by the ECU 8 in the eco-run state in which the engine 4 is deactivated while the vehicle 2 is traveling. When the engine speed is equal to or higher than the engine speed (engine stop rotational speed), the input clutch 10 is controlled to execute engagement control. When the engine speed is less than the engine speed, the input clutch 10 is controlled to perform release control. By executing this, the engine 4 can be started properly while the vehicle 2 is traveling.

  Here, the engine speed is determined with respect to the engine speed in order to determine whether or not the engine 4 can be restarted by fuel injection into the combustion chamber of the engine 4 without performing cranking by an electric motor or the like. The threshold value is set, and typically corresponds to the rotational speed at which the engine 4 in the operating state is stalled. In other words, the engine speed corresponds to the lowest engine speed at which the engine 4 can autonomously rotate by fuel injection into the combustion chamber. The engine speed is preset by, for example, actual vehicle evaluation and stored in the storage unit of the ECU 8.

  When the engine speed detected by the engine speed sensor 70 is equal to or higher than the engine speed, for example, when the ECU 8 is in the eco-run state, the first engagement force that is set in advance for the input clutch 10 is set as the engagement control. It controls to the state engaged with the above engagement force. On the other hand, when the ECU 8 is in the eco-run state, for example, when the engine speed is less than the engine stall speed detected by the engine speed sensor 70, the ECU 8 sets the input clutch 10 to a second engagement smaller than the first engagement force as release control. Control is made so that the engagement is released with an engagement force equal to or less than the resultant force. In the engagement control and the release control, the ECU 8 controls the TM hydraulic control device 14 to adjust the hydraulic pressure (clutch hydraulic pressure) of the hydraulic oil supplied to the input clutch 10 to adjust the engagement force, thereby operating the input clutch 10. Adjust.

  Then, when the engine 8 is started after the eco-run state is set, when the engine speed is equal to or higher than the engine speed, the engine 8 is supplied with fuel to the engine 4 after performing the engagement control. 4 is restarted. On the other hand, when starting the engine 4 after setting the eco-run state, when the engine speed is less than the engine speed, the ECU 8 performs the release control and then performs the clutch by the starter 18 (or motor generator) as an electric motor. The engine 4 is restarted by the ranking and supply of fuel to the engine 4.

  In other words, the ECU 8 determines the restart method when the engine 4 is restarted based on the current engine speed in the eco-run state, and changes the operating state of the input clutch 10 accordingly. The ECU 8 executes the engagement control when the engine speed is a speed that does not require cranking by the starter 18 when the engine is restarted and can be restarted by returning the fuel injection to the combustion chamber. The input clutch 10 is brought into an engaged state of a predetermined value or more. On the other hand, when the engine speed is a speed that requires cranking by the starter 18 when the engine is restarted, the ECU 8 executes the release control so that the input clutch 10 is in a released state below a predetermined level.

  Here, the first engagement force in the engagement control is such that a predetermined torque capacity is ensured in the input clutch 10, that is, power that is large enough to avoid engine stall from the drive wheel 3 side to the engine 4 side. Any size that can be transmitted is acceptable. In the engagement control, the ECU 8 may control the input clutch 10 to be engaged with an engagement force larger than the first engagement force. In this case, as long as the engagement force is greater than or equal to the first engagement force, for example, the input clutch 10 may have a size that allows the input clutch 10 to be completely engaged, or the rotation member 10a and the rotation member 10b slip. The magnitude | size used as a state (semi-engagement state) may be sufficient.

  In addition, the second engagement force in the release control is set to be at least smaller than the first engagement force, and may be, for example, a magnitude that can prevent the occurrence of a shock at the time of cranking by the starter 18 and reduce the load on the starter 18. . In the release control, the ECU 8 may perform control so that the engagement of the input clutch 10 is released with an engagement force not greater than the second engagement force. The engagement force in this case may be, for example, a magnitude that allows the input clutch 10 to be completely released, i.e., 0, as long as the magnitude is equal to or less than the second engagement force, or may be 0, or the rotation member 10a and the rotation member 10b. May be in a size that causes a slip state (half-engaged state).

  2 and 3, the horizontal axis is the time axis, and the vertical axis is the starter drive flag, fuel injection flag, eco-run execution flag, accelerator opening, engine speed, and clutch oil pressure. Here, the clutch hydraulic pressure is a hydraulic pressure for engaging the rotating member 10a and the rotating member 10b in the input clutch 10, and an engaging force for engaging the rotating member 10a and the rotating member 10b in the input clutch 10 is as follows. The size corresponds to the clutch hydraulic pressure.

  For example, as shown in FIG. 2, when the accelerator opening sensor 71 detects that the accelerator is off, that is, the accelerator opening is smaller than a predetermined opening, the ECU 8 turns on the eco-run execution flag and the fuel injection flag. Is turned off, fuel cut control for stopping the fuel supply to the combustion chamber of the engine 4 is executed, and the vehicle 2 is brought into an eco-run state. Thereafter, the engine 4 is brought into a stopped state, and accordingly, the engine speed decreases. At this time, in FIG. 2, the ECU 8 controls the TM oil pressure control device 14 as the engagement control, and the clutch oil pressure is set to the first oil pressure P1, because the engine speed has changed at the engine speed more than the engine speed. The engagement force of the input clutch 10 is maintained at a magnitude equal to or greater than the first engagement force, and the input clutch 10 is brought into an engagement state in which a predetermined torque capacity or more is ensured. Then, when the accelerator opening is detected by the accelerator opening sensor 71 at time t1, the ECU 8 keeps the starter drive flag off, turns on the fuel injection flag, and does not perform cranking by the starter 18. Then, supply of fuel to the engine 4 is started, and the engine 4 is restarted.

  On the other hand, as shown in FIG. 3, when the engine speed becomes less than the engine speed nesten at time t2, the ECU 8 controls the TM hydraulic control device 14 as release control, and the clutch hydraulic pressure from the first hydraulic pressure P1. The engagement pressure of the input clutch 10 is reduced to a value equal to or smaller than the second engagement force by reducing the second hydraulic pressure P2 to a small value, and the input clutch 10 is set in a disengaged state in which the torque capacity is equal to or less than a predetermined value. When the accelerator opening is detected by the accelerator opening sensor 71 at time t3, the ECU 8 turns on the starter drive flag, turns on the fuel injection flag, performs cranking by the starter 18, and supplies fuel to the engine 4. Is started, and the engine 4 is restarted.

  Therefore, when the engine speed is equal to or higher than the engine speed, the vehicle control system 1 keeps the input clutch 10 in an engaged state greater than or equal to a predetermined value, so that the vehicle control system 1 enters the combustion chamber without being cranked by the starter 18. When the fuel injection is restored, the engine 4 can be restarted by so-called pushing. As a result, the vehicle control system 1 can restart the engine 4 without waiting for the operation of the input clutch 10, thereby shortening the time required for starting and improving the responsiveness at the time of engine restart. it can. As a result, for example, the vehicle control system 1 can output a driving force quickly while suppressing a time delay in returning from the eco-run state. For example, the driver's acceleration request operation (for example, accelerator depression) Since the vehicle 2 can be accelerated with high responsiveness to the operation), the deterioration of drivability can be suppressed. Moreover, since the vehicle control system 1 can restart the engine 4 without generating the power for cranking by the starter 18, it can suppress consumption of energy and can reduce power consumption. it can.

  Furthermore, when the vehicle control system 1 restarts the engine 4 by pushing the fuel injection back to the combustion chamber as described above, the input clutch 10 is maintained in an engaged state of a predetermined level or more, for example, Then, when the input clutch 10 is reengaged after being completely released and the engine 4 is restarted by pushing, the torque corresponding to the inertia due to the increase in the engine speed is driven via the input clutch 10 to the drive wheel 3. It is possible to suppress the transmission to. As a result, the vehicle control system 1 can prevent the deceleration of the vehicle 2 from becoming too large and give the driver a sense of incongruity, and in this respect as well, the drivability can be prevented from deteriorating.

  On the other hand, when the engine speed is less than the engine speed, that is, when the engine 4 is restarted by performing cranking by the starter 18, the vehicle control system 1 releases the input clutch 10 below a predetermined value in advance. Since the state is maintained, the engine 4 can be restarted without waiting for the operation of releasing the input clutch 10. Thereby, the vehicle control system 1 can shorten the time required for starting, can improve the responsiveness at the time of engine restart, and can suppress the deterioration of drivability. In addition, when the vehicle control system 1 performs cranking by the starter 18 and restarts the engine 4, the input clutch 10 is maintained in a released state below a predetermined value, so that a shock is generated during cranking by the starter 18. Generation | occurrence | production can be prevented and the load in the starter 18 can be reduced. Also in this respect, the vehicle control system 1 can suppress deterioration of drivability and can suppress energy consumption.

  Next, an example of control by the ECU 8 will be described with reference to the flowchart of FIG. Note that these control routines are repeatedly executed at a control cycle of several ms to several tens of ms (the same applies to the following description).

  First, the ECU 8 determines whether or not the vehicle 2 is in an eco-run in which the fuel cut control is executed and the operation of the engine 4 is stopped based on various information from the state detection device 7, the operation state of the engine 4, and the like. (ST1).

  When it is determined that the vehicle 2 is not in an eco-run (ST1: No), the ECU 8 repeatedly executes this determination until it is determined that the vehicle 2 is in an eco-run. When the ECU 8 determines that the vehicle 2 is in an eco-run (ST1: Yes), the ECU 8 acquires the engine speed detected by the engine speed sensor 70, and whether the current engine speed ne is equal to or higher than the engine speed nesten. It is determined whether or not (ST2).

  If the ECU 8 determines that the current engine speed ne is equal to or higher than the engine speed nesten (ST2: Yes), is the current clutch hydraulic pressure pcl greater than the engagement control hydraulic pressure pcltie in the preset engagement control? It is determined whether or not (ST3). Here, the preset hydraulic pressure pcltie at the time of engagement control corresponds to the first hydraulic pressure P1 described in FIG. 2, and corresponds to a hydraulic pressure at which the magnitude of the engagement force of the input clutch 10 is equal to or greater than the first engagement force.

  When the ECU 8 determines that the current clutch hydraulic pressure pcl is larger than the engagement control hydraulic pressure pcltie (ST3: Yes), the ECU 8 ends the current control cycle and shifts to the next control cycle. When the ECU 8 determines that the current clutch oil pressure pcl is equal to or lower than the engagement control oil pressure pcltie (ST3: No), the ECU 8 controls the TM oil pressure control device 14 to change the clutch oil pressure pcl to the engagement control oil pressure pcltie. 10 is increased (ST4), the current control cycle is terminated, and the next control cycle is started.

  If the ECU 8 determines in ST2 that the current engine speed ne is less than the engine speed nesten (ST2: No), the current clutch oil pressure pcl is greater than the release control oil pressure pcropn in the preset release control. It is determined whether or not (ST5). Here, the preset release control hydraulic pressure pcropn corresponds to the second hydraulic pressure P2 described with reference to FIG. 3, and corresponds to a hydraulic pressure at which the magnitude of the engagement force of the input clutch 10 is equal to or less than the second engagement force.

  When the ECU 8 determines that the current clutch hydraulic pressure pcl is greater than the release control hydraulic pressure pclopn (ST5: Yes), the ECU 8 controls the TM hydraulic control device 14 to change the clutch hydraulic pressure pcl to the release control hydraulic pressure pclopn. The resultant force is reduced (ST6), the current control cycle is terminated, and the next control cycle is started. When the ECU 8 determines that the current clutch hydraulic pressure pcl is equal to or lower than the release control hydraulic pressure pcropn (ST5: No), the ECU 8 ends the current control cycle and shifts to the next control cycle.

  According to the vehicle control system 1 according to the embodiment described above, during operation of the vehicle 2, an operation state that generates power to be applied to the drive wheels 3 of the vehicle 2 and a non-operation state that stops generation of power are provided. Can be switched between a state in which the engine 4 that can be switched, the rotating member 10a on the engine 4 side and the rotating member 10b on the drive wheel 3 side are engaged so as to be able to transmit power, and a state in which this engagement is released, When the engine 4 is deactivated while the vehicle 2 is traveling, the input clutch 10 that can adjust the engagement force that engages the rotation member 10a on the engine 4 side and the rotation member 10b on the drive wheel 3 side, When the engine speed of the engine 4 is equal to or higher than the preset engine speed, the engagement control is performed to control the input clutch 10 to be engaged with the engagement force equal to or higher than the first engagement force. Engine And a ECU8 for executing a release control that the rotational speed is controlled to a state where the engagement is released input clutch 10 is less than the engine stall rotational speed in the first engagement force smaller than the first engagement force less engagement force. Therefore, the vehicle control system 1 can properly start the engine 4 while the vehicle 2 is traveling.

  In the above description, the vehicle control system 1 has been described as using the engine speed detected by the engine speed sensor 70. However, the present invention is not limited to this, and the current engine speed is determined according to the detection results of other sensors. The number may be estimated and detected. For example, when the lockup clutch of the torque converter 9 is in an engaged state (lockup ON state) and the input shaft of the transmission 11 and the crankshaft of the engine 4 are directly connected, the ECU 8 The input shaft rotational speed of the transmission 11 detected by the shaft rotational speed sensor 73 can be equivalently used as the engine rotational speed. For example, when the lock-up clutch of the torque converter 9 is in the released state (lock-up OFF state), the ECU 8 detects the input shaft speed of the transmission 11 detected by the input shaft speed sensor 73 and the torque converter 9. The engine speed may be estimated and detected based on the reverse drive characteristics. Further, the ECU 8, for example, the output shaft speed of the transmission 11 detected by the output shaft speed sensor 74 (or the vehicle speed detected by a vehicle speed sensor not shown) and the current speed ratio (gear ratio) of the transmission 11. Based on the above, the engine speed may be estimated and detected. In this case, for example, the ECU 8 determines whether or not the engine speed is equal to or higher than the engine speed, and the input shaft speed or the output shaft speed is equal to or higher than a determination threshold set according to the engine speed. You may make it determine whether it exists.

[Embodiment 2]
FIG. 5 is a flowchart for explaining an example of control by the ECU of the vehicle control system according to the second embodiment, FIG. 6 is a diagram showing an example of an engine torque map, and FIG. 7 is a diagram showing an example of a clutch hydraulic pressure map. FIG. 8 is a diagram showing an example of a clutch hydraulic pressure map according to a modification. The vehicle control system according to the second embodiment is different from the first embodiment in that the engagement force adjustment control is executed during the engagement control. In addition, about the structure, effect | action, and effect which are common in embodiment mentioned above, while overlapping description is abbreviate | omitted as much as possible, the same code | symbol is attached | subjected. For the main configuration, refer to FIG. 1 (the same applies to the embodiments described below).

  The vehicle control system 201 of this embodiment described with reference to FIGS. 5 to 8 includes an ECU 208 as a control device. The ECU 208 executes engagement force adjustment control during the engagement control. In this engagement force adjustment control, the ECU 208 controls the TM hydraulic control device 14 and executes control for adjusting the engagement force of the input clutch 10, and sets the engine speed of the engine 4 to the target engine speed corresponding to the engine speed. (Target rotational speed). In this engagement force adjustment control, the ECU 208 adjusts the engagement force of the input clutch 10 to ensure an operation region in which the engine 4 can be restarted by fuel injection return without relying on the cranking by the starter 18 as much as possible.

  In the vehicle control system 201, for example, when the engine speed is equal to or higher than the engine speed in the eco-run state, the input clutch 10 is maintained in an engaged state of a predetermined value or higher, so that the engine speed is high in some cases. As a result, a large engine brake may act on the vehicle 2 due to the negative engine torque, that is, the engine brake torque. In this case, for example, when the vehicle 2 is decelerating more than necessary by the engine brake in an inertial running state with the accelerator off, re-acceleration is required when maintaining a predetermined vehicle speed. It may worsen and be disadvantageous in terms of fuel consumption.

  However, the vehicle control system 201 acts on the vehicle 2 by controlling the TM hydraulic control device 14 as the engagement force adjustment control and executing the engagement force adjustment control of the input clutch 10 when the ECU 208 performs the engagement control. The size of the engine brake can be adjusted. Typically, the ECU 208 executes the engagement force adjustment control when the engine speed when the input clutch 10 is fully engaged during the engagement control is sufficiently higher than the engine speed. By making the engagement force relatively small so that the input clutch 10 is in a slip state in which the rotating member 10a and the rotating member 10b slip, the engine speed is set to the target engine speed corresponding to the engine speed. Is as low as possible. On the other hand, the ECU 208 performs the engagement force adjustment control when the engine speed when the input clutch 10 is in the fully engaged state during the engagement control is almost equal to the engine speed, or when there is almost no margin. This is executed to relatively increase the engagement force so that the input clutch 10 is almost completely engaged, and the engine speed is set to the target engine speed corresponding to the engine speed, thereby increasing the engine speed as much as possible. .

  Therefore, the vehicle control system 201 can make the engine speed as low as possible within a range where the engine 4 can be restarted without being cranked by the starter 18. As a result, the vehicle control system 201 causes a large engine brake to act on the vehicle 2 while maintaining the engine speed at which the engine 4 can be restarted without generating the power for cranking by the starter 18 as much as possible. And deceleration of the vehicle 2 can be optimized. As a result, the vehicle control system 201 can suppress deterioration of drivability and suppress deterioration of fuel consumption.

  Next, an example of control by the ECU 208 will be described with reference to the flowchart of FIG.

  First, the ECU 208 determines whether or not the vehicle 2 is in an eco-run based on various information from the state detection device 7, the operating state of the engine 4, and the like (ST21).

  When it is determined that the vehicle 2 is not in an eco-run (ST21: No), the ECU 208 repeatedly executes this determination until it is determined that the vehicle 2 is in an eco-run. When it is determined that the vehicle 2 is in an eco-run (ST21: Yes), the ECU 208 determines whether or not the engine speed nest when the input clutch 10 is fully engaged is equal to or higher than the engine speed nesten. (ST22). The ECU 208 can estimate the engine speed nest when the input clutch 10 is fully engaged based on, for example, the input shaft speed of the transmission 11 detected by the input shaft speed sensor 73.

  When the ECU 208 determines that the engine speed nest is equal to or higher than the engine speed nesten (ST22: Yes), the TM hydraulic control device 14 is controlled to adjust the clutch hydraulic pressure pcl to the adjusted hydraulic pressure pclcnti and adjust the engagement force of the input clutch 10. (ST23), the actual engine speed ne is converged to the target engine speed near the engine speed nesten, the current control cycle is terminated, and the next control cycle is started.

  Here, the ECU 208 sets the target engine speed, for example, according to the driving state of the vehicle 2. The ECU 208, for example, takes into account the influence of the variation in engagement force, the variation in the engine 4, the disturbance according to the driving environment, and the like so that the engine speed will not be interrupted even if the actual engine speed fluctuates slightly. A target engine speed may be set.

  Then, the ECU 208 sets the adjustment hydraulic pressure pclcnti based on the target engine speed. For example, the ECU 208 first calculates the engine torque based on the engine torque map m1 illustrated in FIG. In the engine torque map m1, the horizontal axis indicates the engine speed, and the vertical axis indicates the engine torque. The engine torque map m1 describes the relationship between the engine speed and the engine torque during fuel injection cut. The engine torque map m1 is stored in the storage unit of the ECU 208 after a relationship between the engine speed and the engine torque during fuel injection cut is set in advance based on actual vehicle evaluation and the like. In the engine torque map m1, the engine torque represents a negative engine torque, that is, an engine friction torque. The engine torque decreases as the engine speed increases (the absolute value increases). In other words, the engine friction torque increases as the engine speed increases. The ECU 208 obtains a negative engine torque corresponding to the set target engine speed, that is, an engine friction torque, based on the engine torque map m1.

  Then, the ECU 208 calculates the adjustment hydraulic pressure pclcnti based on, for example, the clutch hydraulic pressure map m2 illustrated in FIG. In the clutch hydraulic pressure map m2, the horizontal axis indicates the engine friction torque, and the vertical axis indicates the clutch hydraulic pressure. The clutch hydraulic pressure map m2 describes the relationship between the engine friction torque during the engagement force adjustment control and the clutch hydraulic pressure (adjusted hydraulic pressure pclcnti). The clutch hydraulic pressure map m2 is stored in the storage unit of the ECU 208 after the relationship between the engine friction torque during the engagement force adjustment control and the clutch hydraulic pressure is set in advance based on actual vehicle evaluation and the like. In this clutch oil pressure map m2, the clutch oil pressure increases with an increase in engine friction torque (in other words, a decrease in negative engine torque). The ECU 208 obtains the clutch hydraulic pressure corresponding to the calculated engine friction torque as the adjusted hydraulic pressure pclcnti based on the clutch hydraulic pressure map m2.

  In the present embodiment, the ECU 208 calculates the adjustment hydraulic pressure pclcnti using the engine torque map m1 illustrated in FIG. 6 and the clutch hydraulic pressure map m2 illustrated in FIG. 7, but the present embodiment is not limited to this. The ECU 208 may obtain the adjustment hydraulic pressure pclcnti based on, for example, a mathematical model corresponding to the engine torque map m1 illustrated in FIG. 6 and the clutch hydraulic pressure map m2 illustrated in FIG.

  When the ECU 208 determines in ST22 that the engine speed nest is less than the engine speed nesten (ST22: No), the ECU 208 controls the TM hydraulic control device 14 to change the clutch hydraulic pressure pcl to the release control hydraulic pressure pcropn. (ST24), the input clutch 10 is set to a predetermined or lower release state, the current control cycle is terminated, and the next control cycle is started.

  According to the vehicle control system 201 according to the embodiment described above, the engine 4 can be appropriately started while the vehicle 2 is traveling. The vehicle control system 201 according to the present embodiment executes engagement force adjustment control for adjusting the engagement force of the input clutch 10 when the ECU 208 performs engagement control, and sets the engine speed of the engine 4 according to the engine speed. Since the target engine speed is set, the deterioration of drivability can be suppressed and the deterioration of fuel consumption can be suppressed.

  ECU 208 may perform feedback control based on the actual engine speed. In this case, in the engagement force adjustment control, the ECU 208 determines the actual engine speed based on the deviation between the actual engine speed detected by the engine speed sensor 70 and the target engine speed corresponding to the engine speed, for example. The clutch hydraulic pressure of the input clutch 10 is adjusted to adjust the engagement force so as to converge to the target engine speed. Thereby, the vehicle control system 201 can suppress the influence of various dispersions to the minimum, and can improve the control precision of engagement force adjustment control.

  Further, for example, the ECU 208 executes learning control for learning the magnitude of the clutch oil pressure (adjusted oil pressure pclcnti) in the engagement force adjustment control based on the actual engine speed detected by the engine speed sensor 70. Good. In this case, in this learning control, the ECU 208 detects the actual engine speed with the engine speed sensor 70 during execution of the engagement force adjustment control, and the target engine according to the detected actual engine speed and engine speed. Based on the deviation from the rotational speed, the magnitude of the clutch hydraulic pressure in the next engagement force adjustment control is changed and corrected so that the actual engine rotational speed converges to the target engine rotational speed. Thereby, the vehicle control system 201 can suppress the influence of various dispersions to the minimum, and can improve the control precision of engagement force adjustment control.

  Further, for example, during the engagement force adjustment control, the ECU 208 relatively reduces the engagement force when the vehicle speed of the vehicle 2 is relatively high, and relatively sets the engagement force when the vehicle speed of the vehicle 2 is relatively low. It may be made larger. In this case, the ECU 208 calculates the adjustment hydraulic pressure pclcnti based on, for example, the clutch hydraulic pressure map m3 illustrated in FIG. The clutch hydraulic pressure map m3 is substantially the same as the clutch hydraulic pressure map m2 (see FIG. 7), but further differs from the clutch hydraulic pressure map m2 in that the relationship between the vehicle speed and the clutch hydraulic pressure (adjusted hydraulic pressure pclcnti) is also described. . In the clutch hydraulic pressure map m3, the clutch hydraulic pressure increases as the engine friction torque increases and decreases as the vehicle speed increases. Then, the ECU 208 detects the vehicle speed of the vehicle 2 and obtains the calculated engine friction torque and the clutch hydraulic pressure corresponding to the detected vehicle speed as the adjusted hydraulic pressure pclcnti based on the clutch hydraulic pressure map m3. The ECU 208 may detect the vehicle speed of the vehicle 2 based on the output shaft rotation speed of the transmission 11 detected by the output shaft rotation speed sensor 74, or separately includes a vehicle speed sensor, and according to the detection result of the vehicle speed sensor. Thus, the vehicle speed of the vehicle 2 may be detected.

  Therefore, the ECU 208 sets the adjustment hydraulic pressure pclcnti relatively low when the vehicle speed of the vehicle 2 is relatively high and performs the adjustment hydraulic pressure pclcnti when the vehicle speed of the vehicle 2 is relatively low during the engagement force adjustment control. The engagement force can be set relatively low when the vehicle speed of the vehicle 2 is relatively high, and the engagement force can be set relatively low when the vehicle speed of the vehicle 2 is relatively low. Can be bigger. As a result, the vehicle control system 201 can relatively reduce the engine brake at a high vehicle speed at which the engine speed tends to be high, and can suppress the engine brake from acting excessively. . Conversely, the vehicle control system 201 can relatively increase the engine brake at a low vehicle speed at which the engine speed tends to be low, and can suppress a shortage of the engine brake. Thereby, the vehicle control system 201 can apply an engine brake more appropriately according to the vehicle speed.

  Further, the ECU 208 prohibits the engagement force adjustment control during the execution of the engine brake increase control (engine brake increase control) for relatively increasing the engine brake (engine brake) using the rotational resistance of the engine 4, for example. May be. In this case, the ECU 208 performs engine brake increase control for increasing the engine brake by increasing the engine speed more than that during normal operation by, for example, driving support control such as uphill / downhill control, sudden braking control, and accelerator sudden closing control. By prohibiting the engagement force adjustment control during execution, it is possible to suppress the shortage of the engine brake when a relatively large engine brake is required. Thereby, the vehicle control system 201 can ensure an engine brake appropriately.

  For example, when the deceleration of the vehicle 2 due to a factor other than engine braking using the rotational resistance of the engine 4 is relatively large, the ECU 208 detects, for example, a braking operation to the brake pedal by the driver by the brake sensor 72. When braking by the brake device 6 is being performed, the engagement force adjustment control may be prohibited and the engagement force of the input clutch 10 may be relatively increased and held. Thereby, the vehicle control system 201 can suppress giving a sense of incongruity due to a change in deceleration when the vehicle 2 is decelerated. Thereby, the vehicle control system 201 can continue control appropriately even when the actual engine speed changes suddenly, for example, due to the feedback control described above.

[Embodiment 3]
FIG. 9 is a time chart illustrating an example of control by the ECU of the vehicle control system according to the third embodiment. The vehicle control system according to the third embodiment is different from the first and second embodiments in that the engine stop rotational speed is changed according to the state of the vehicle.

  The vehicle control system 301 of this embodiment described with reference to FIG. 9 includes an ECU 308 as a control device. The ECU 308 changes the engine speed according to the state of the vehicle 2. For example, the ECU 308 detects the engine oil temperature, the engine coolant temperature, the engine coolant temperature sensor 76, the coolant temperature sensor 76, the intake sensor 77, the fuel property sensor 78, the TM oil temperature sensor 79, and the like. Detects intake air density, fuel properties, and hydraulic oil temperature.

  Here, as described above, the engine speed corresponds to the minimum engine speed at which the engine 4 can autonomously rotate by fuel injection into the combustion chamber of the engine 4. There is a possibility that the temperature may change with fluctuations in external factors such as the temperature of the cooling water, the intake air density, the fuel properties, the temperature of the hydraulic oil, and the like.

  Therefore, the ECU 308 determines the temperature of the engine oil supplied to the engine 4, the temperature of engine cooling water that cools the engine 4, the intake air density (for example, altitude) of the engine 4, and the fuel supplied to the combustion chamber of the engine 4. The engine speed is changed and corrected based on the fuel properties or the temperature of the hydraulic oil supplied to the power transmission device 5 or the like.

  For example, since the engine startability decreases when the temperature of the engine coolant is relatively low, the ECU 308 sets the engine speed relatively higher than normal according to the temperature of the engine coolant, When the water temperature is relatively high, the engine speed is set relatively low. Thereby, the vehicle control system 301 can start the engine 4 properly even when the engine coolant temperature is low and the engine startability is low.

  Further, for example, when the temperature of the engine oil or the temperature of the hydraulic oil is relatively low, that is, when the viscosity of the engine oil or the hydraulic oil is relatively large, the ECU 308 Since the drag resistance of the engine oil becomes relatively large, the engine speed or the operating oil temperature is set to a relatively high engine speed according to the engine oil temperature or the operating oil temperature. When the temperature is relatively high, that is, when the viscosity of the engine oil and hydraulic oil is relatively small, the engine speed is set to be relatively lower than usual. Thereby, the vehicle control system 301 can start the engine 4 properly even when the viscosity of the engine oil and the hydraulic oil is large and the drag resistance of each rotating member is large.

  Further, for example, when the intake air density of the engine 4 is relatively low, for example, when the altitude of the traveling position of the vehicle 2 is relatively high, the ECU 308 causes the energy of the engine combustion to be relatively higher than that in normal times. Therefore, when the engine speed is set to be relatively higher than normal according to the intake air density or altitude, and the intake air density is relatively high, for example, the altitude of the traveling position of the vehicle 2 is relatively low. If the engine speed is low, the engine speed is set relatively lower than usual. As a result, the vehicle control system 301 can start the engine 4 properly even when the intake air density of the engine 4 is low and the energy due to engine combustion is low.

  Further, for example, the ECU 308 sets the engine speed according to the fuel property of the fuel supplied to the combustion chamber of the engine 4 so that the engine 4 is properly started even when the fuel property has changed. be able to.

  Further, the ECU 308 may change the engine speed based on the changing speed of the engine speed of the engine 4. Here, in FIG. 9, the horizontal axis is the time axis, and the vertical axis is the engine speed, the clutch hydraulic pressure, and the engagement force of the input clutch 10. When the vehicle control system 301 adjusts the engagement force of the input clutch 10 to a predetermined magnitude, as illustrated in FIG. 9, the vehicle control system 301 controls the TM hydraulic control device 14 to reduce the clutch hydraulic pressure at time t31. A predetermined period T1 is required according to the release characteristics of the input clutch 10 and the like until the time t32 when the engagement force is actually set to a predetermined magnitude. For this reason, the ECU 308 actually sets the engine speed to the engine speed so that the engagement force becomes a predetermined magnitude that is required when the engine speed reaches the engine speed. Prior to this, it is preferable to promptly control in view of the predetermined period T1. However, since the degree of change in the engine speed varies depending on the operating conditions and the like, there is a possibility that the expected effect cannot be obtained even if the timing for early control is fixedly set as a constant value.

  Therefore, the ECU 308 of the present embodiment calculates the change speed of the engine speed detected by the engine speed sensor 70, and executes control to change the engine speed nexten based on the change speed of the engine speed. As a result, the ECU 308 can appropriately promptly control the actual engine speed before it reaches the engine speed.

  For example, when the engine speed changes as indicated by the solid line L1 in FIG. 9, the ECU 308 reduces the actual engine speed and sets the engine speed to the set engine speed in anticipation of a change (decrease) in the rotational speed during the predetermined period T1. When it becomes nesten (corresponding to nestencal described later), control for reducing the engagement force is started. Thus, the ECU 308 can realize the engagement force required in the input clutch 10 when the engine speed reaches the actual engine speed. Further, for example, when the engine speed changes as indicated by a dotted line L1 ′ whose change speed is larger than the solid line L1, the ECU 308 sets the actual engine speed higher than the set engine speed nesten. Control is started when the value reaches several nesten '(corresponding to nestencal described later). Thereby, even if the change speed of the engine speed fluctuates, the ECU 308 can realize the engagement force required in the input clutch 10 when the engine speed reaches the actual engine speed. .

Specifically, the ECU 308 acquires, for example, the engine speed ne detected by the engine speed sensor 70, and calculates the change speed (change amount per unit time) Δne of the engine speed ne. The change speed Δne of the engine speed ne corresponds to a decrease degree or an increase degree of the engine speed ne. Next, the ECU 308 sets a set engine speed nestencal based on the change speed Δne of the engine speed ne. For example, the ECU 308 can calculate the set engine speed nestencal based on the change speed Δne, the predetermined period T1, and the reference engine speed nesten using the following formula (1). The ECU 308 can set the optimum set engine speed nestencal regardless of the change speed of the engine speed by making the set engine speed nestencal variable according to the change speed Δne based on this equation.

nestencal = Δne × T1 + nesten (1)

  According to the vehicle control system 301 according to the embodiment described above, the engine 4 can be properly started while the vehicle 2 is traveling. And since the vehicle control system 301 of this embodiment changes an engine speed according to the state of the vehicle 2, it can start the engine 4 appropriately according to the state of the vehicle 2. FIG. Note that the ECU 308 may change the engine speed based on, for example, the deceleration of the vehicle 2 or until the engagement force of the input clutch 10 actually reaches the target magnitude after the control is started. The engine speed may be changed based on, for example, a hydraulic response delay characteristic corresponding to the oil temperature of the hydraulic control system of the input clutch 10.

  In addition, the vehicle control system which concerns on embodiment of this invention mentioned above is not limited to embodiment mentioned above, A various change is possible in the range described in the claim. The vehicle control system according to the present embodiment may be configured by combining a plurality of the embodiments described above.

  In the above description, the engaging device is described as being an input clutch of a transmission, but is not limited thereto. The engagement device may be a lock-up clutch of a torque converter. In the above description, the engagement device has been described as being operated by the hydraulic pressure of the hydraulic oil, but may be an electromagnetic engagement device.

  The vehicle described above may be a so-called “hybrid vehicle” provided with a motor generator as an electric motor capable of generating electricity in addition to the engine 4 as a driving power source.

  As described above, the vehicle control system according to the present invention is suitable for application to vehicle control systems mounted on various vehicles.

1, 201, 301 Vehicle control system 2 Vehicle 3 Drive wheel 4 Engine (internal combustion engine)
5 Power transmission device 6 Brake device 7 State detection device 8, 208, 308 ECU (control device)
9 Torque converters 10a, 10b Rotating member 10 Input clutch (engagement device)
11 Transmission 18 Starter (electric motor)

Claims (12)

An internal combustion engine capable of switching between an operating state for generating power to be applied to driving wheels of the vehicle and a non-operating state for stopping generation of the power during traveling of the vehicle;
The internal combustion engine side rotation member and the drive wheel side rotation member can be switched between a state in which power can be transmitted and a state in which the engagement is released, and the internal combustion engine side rotation member and An engagement device capable of adjusting an engagement force for engaging the rotating member on the drive wheel side;
If the engine speed of the internal combustion engine is equal to or higher than a preset engine stop rotational speed when the internal combustion engine is deactivated while the vehicle is running, the engagement device is set to a first engagement force or higher. The engagement control is performed to control the engagement state with the engagement force of the internal combustion engine, and when the engine rotation speed of the internal combustion engine is less than the engine stop rotation speed, the engagement device is made smaller than the first engagement force. And a control device that performs release control for controlling the engagement to a released state with an engagement force of 2 or less engagement force.
Vehicle control system. The control device, when starting the internal combustion engine after the internal combustion engine is deactivated while the vehicle is running, when the engine rotational speed of the internal combustion engine is equal to or higher than the engine stop rotational speed, After executing the engagement control, restart the internal combustion engine by supplying fuel to the internal combustion engine, and after executing the release control when the engine rotation speed of the internal combustion engine is less than the engine stop rotation speed Restarting the internal combustion engine by cranking with an electric motor and supplying fuel to the internal combustion engine;
The vehicle control system according to claim 1. The control device executes engagement force adjustment control for adjusting the engagement force during the engagement control, and sets the engine rotation speed of the internal combustion engine to a target rotation speed corresponding to the engine stop rotation speed.
The vehicle control system according to claim 1 or 2. In the engagement force adjustment control, the control device reduces the engagement force when the vehicle speed of the vehicle is relatively high, and reduces the engagement force when the vehicle speed of the vehicle is relatively low. Relatively large,
The vehicle control system according to claim 3. The control device prohibits the engagement force adjustment control during execution of engine brake increase control for relatively increasing engine brake using rotational resistance of the internal combustion engine.
The vehicle control system according to claim 3 or 4. The control device prohibits the engagement force adjustment control and relatively increases the engagement force when the deceleration of the vehicle due to a factor other than engine braking using the rotational resistance of the internal combustion engine is relatively large. Hold
The vehicle control system according to any one of claims 3 to 5. The control device changes the engine stop rotational speed based on the temperature of oil supplied to the internal combustion engine.
The vehicle control system according to any one of claims 1 to 6. The control device changes the engine stop rotational speed based on the temperature of a cooling medium that cools the internal combustion engine.
The vehicle control system according to any one of claims 1 to 7. The control device changes the engine stop rotational speed based on the intake air density of the internal combustion engine.
The vehicle control system according to any one of claims 1 to 8. The control device changes the engine stop rotational speed based on a fuel property of fuel supplied to a combustion chamber of the internal combustion engine;
The vehicle control system according to any one of claims 1 to 9. The control device changes the engine stop rotational speed based on the temperature of oil supplied to a power transmission device including the engagement device.
The vehicle control system according to any one of claims 1 to 10. The control device changes the engine stop rotational speed based on the change speed of the engine rotational speed of the internal combustion engine.
The vehicle control system according to any one of claims 1 to 11.

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