JP2018059407A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle capable of stabilizing startability of a vehicle at the time of IDS return.SOLUTION: An IDS control has two modes, i.e., a first mode and a second mode. In the first mode, an engine 2 is restarted while a forward clutch C is engaged. In the second mode, the engine 2 is restarted while the forward clutch C is released, or the engine 2 is restarted while the forward clutch C is engaged. The IDS control in the second mode is banned when a traveling time from when a start switch of a vehicle 1 is turned on is less than a second time, and the IDS control in the first mode is allowed when the traveling time from when the start switch of the vehicle 1 is turned on becomes not less than a first time shorter than a second time.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a control device used in a vehicle adopting IDS (idling stop) control.

  In recent years, IDS control has been adopted for vehicles using an engine as a drive source for the purpose of improving fuel consumption. In a vehicle employing IDS control, for example, when the vehicle speed drops below a predetermined IDS start vehicle speed due to a driver's brake operation, the engine is automatically stopped (idling stop). Thereafter, when the driver releases the brake operation, the engine is automatically restarted.

  There is a vehicle type that employs IDS control even in a vehicle equipped with a belt-type continuously variable transmission (CVT). In the vehicle type, for example, a forward clutch is interposed between the torque converter and the primary pulley of the continuously variable transmission. When the engine is stopped (deceleration IDS) while the vehicle is decelerating, the forward travel is performed. The clutch is released. When the engine is stopped while the vehicle is decelerating, the clamping pressure, which is the hydraulic pressure supplied to the secondary pulley of the continuously variable transmission, is set to the minimum pressure. As a result, the torque applied to the belt of the continuously variable transmission during vehicle deceleration can be reduced, and the occurrence of slippage (belt slip) between the pulley and the belt due to the inertia torque can be suppressed during sudden braking. it can.

JP 2013-181408 A

  However, as a result of repeated research by the inventors of the present application, when the forward clutch is released in response to the start of the deceleration IDS, the state of the forward clutch at the time of engine restart (at the time of IDS return) is not stable, and the forward clutch It has been found that there is a difference in vehicle startability depending on the state of the vehicle.

  An object of the present invention is to provide a vehicle control device capable of stabilizing the startability of a vehicle when returning to IDS.

  In order to achieve the above object, a vehicle control device according to the present invention transmits an engine, a belt-type continuously variable transmission that shifts power transmitted from the engine to wheels, and transmits power between the engine and wheels. Control device for use in a vehicle equipped with a friction engagement element that is engaged / released to shut off, and stops the engine when the IDS start condition is satisfied, and engine according to the satisfaction of the IDS return condition IDS control means for executing IDS control to restart the engine and permission / rejection setting means for setting permission and / or prohibition of execution of IDS control. The IDS control includes an engine in a state in which the friction engagement element is engaged. And a second mode in which the frictional engagement element is released between when the IDS start condition is satisfied and when the IDS return condition is satisfied. At least one related conditions of the travel time or travel distance of the order of the vehicle is switched between the first mode and the second mode.

  According to this configuration, in the IDS control, the engine is stopped in response to the establishment of the IDS start condition (IDS start request), and the engine is restarted in response to the establishment of the IDS return condition while the engine is stopped (IDS return request). It is started. The IDS control includes a first mode in which the engine is restarted with the friction engagement element engaged, and a second mode in which the friction engagement element is released between the establishment of the IDS start condition and the establishment of the IDS return condition. And are included.

  For example, when the engine is stopped (deceleration IDS) in response to the establishment of the IDS start condition while the vehicle is decelerating, the friction engagement element is released by executing the IDS control in the second mode. Occurrence of belt slip and clutch slip due to inertia torque during sudden braking is suppressed. However, in the IDS control in the second mode, the IDS return condition may be satisfied in a state where the friction engagement element is released. In this case, air is contained in the hydraulic chamber of the pulley of the continuously variable transmission. For this reason, the rise of the hydraulic pressure (sheave pressure) in the hydraulic chamber is delayed, and accordingly, the engagement of the friction engagement elements may be delayed. When the engagement of the friction engagement element is delayed, the startability (acceleration performance) of the vehicle is reduced, or the turbine rotation of the torque converter is blown up with a time lag until the engagement of the friction engagement element. A shock may occur during the engagement.

  Therefore, the conditions relating to the travel time or travel distance of the vehicle for setting whether to execute the IDS control are switched between the first mode and the second mode. Thereby, the IDS control in the second mode is prohibited from being executed until the travel time or travel distance of the vehicle reaches a predetermined value, and the IDS control in the first mode is shorter than the IDS control in the second mode. It is possible to permit execution based on the travel distance. By appropriately setting the predetermined value, it is possible to exclude air from the hydraulic chamber of the pulley until the execution of the IDS control in the second mode is permitted. Therefore, the time lag of the engagement of the friction engagement elements and the occurrence of shock can be suppressed. On the other hand, since the IDS control in the first mode can be executed at an early stage, it is possible to obtain the effect of improving the fuel consumption by executing the IDS control in the first mode.

  ADVANTAGE OF THE INVENTION According to this invention, the effect of the fuel consumption improvement by IDS control can be heightened, stabilizing the startability of the vehicle at the time of IDS return.

It is a figure which shows the structure of the principal part of the vehicle by which the control apparatus which concerns on one Embodiment of this invention is mounted. It is a figure which shows the time change of the turbine rotation speed at the time of 1st clutch control, an input shaft rotation speed, an engine rotation speed, the ON / OFF state of an electric oil pump, and the engagement / release state of a forward clutch. It is a figure which shows the time change of the turbine rotation speed at the time of 2nd clutch control, an input shaft rotation speed, an engine rotation speed, the ON / OFF state of an electric oil pump, and the engagement / release state of a forward clutch. It is a table | surface for demonstrating permission and prohibition of execution of IDS control according to the mode of IDS control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Vehicle configuration>
FIG. 1 is a diagram illustrating a configuration of a main part of a vehicle 1 on which a control device according to an embodiment of the present invention is mounted.

  The vehicle 1 is an automobile that uses the engine 2 as a drive source.

  The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) that injects fuel into the intake air, and an ignition plug that generates electric discharge in the combustion chamber. It has been. The engine 2 is also provided with a starter for starting the engine 2.

  The vehicle 1 is also equipped with a torque converter 3 and a belt-type continuously variable transmission (CVT) 4 for transmitting the output of the engine 2 to the drive wheels.

  The continuously variable transmission 4 includes an input shaft 11 to which power from the engine 2 is input, a primary shaft 12 to which power is transmitted from the input shaft 11, a secondary shaft 13 provided in parallel to the primary shaft 12, A primary pulley 14 supported so as not to rotate relative to the shaft 12, a secondary pulley 15 supported so as not to rotate relative to the secondary shaft 13, and a belt 16 wound around the primary pulley 14 and the secondary pulley 15. Yes.

  The primary pulley 14 is disposed so as to face the fixed sheave 21 fixed to the primary shaft 12 with the belt 16 sandwiched between the fixed sheave 21 and is supported by the primary shaft 12 so as to be movable in the axial direction and not to be relatively rotatable. 22. A piston 23 fixed to the primary shaft 12 is provided on the opposite side of the movable sheave 22 from the fixed sheave 21, and a piston chamber (hydraulic chamber) 24 is formed between the movable sheave 22 and the piston 23. Yes.

  The secondary pulley 15 is disposed so as to face the fixed sheave 25 fixed to the secondary shaft 13 and the fixed sheave 25 with the belt 16 interposed therebetween, and is supported by the secondary shaft 13 so as to be movable in the axial direction but not relatively rotatable. A movable sheave 26 is provided. A piston 27 fixed to the secondary shaft 13 is provided on the opposite side of the movable sheave 26 from the fixed sheave 25, and a piston chamber (hydraulic chamber) 28 is formed between the movable sheave 26 and the piston 27. Yes.

  Although not shown, a bias spring for applying an initial clamping pressure (initial thrust) to the belt 16 is interposed between the movable sheave 26 and the piston 27. The movable sheave 26 and the piston 27 are biased in a direction away from each other by the elastic force of the bias spring.

  A hydraulic advance clutch C is interposed between the torque converter 3 and the input shaft 11. The forward clutch C is engaged / released to transmit / cut off the power from the engine 2.

  A hydraulic circuit 31 for supplying hydraulic pressure to the torque converter 3, the primary pulley 14, the secondary pulley 15, the forward clutch C and the like is provided along with the continuously variable transmission 4. Furthermore, a mechanical oil pump (MOP) 32 that is driven by the power of the engine 2 and an electric oil pump (EOP) 33 that is driven by the power of the electric motor are provided as sources of hydraulic pressure. The hydraulic circuit 31 is supplied with hydraulic pressure generated by the mechanical oil pump 32 and the electric oil pump 33 independently of each other.

  The vehicle 1 includes an ECU (Electronic Control Unit) having a configuration including a microcomputer (microcontroller unit). The microcomputer includes, for example, a CPU, ROM and RAM, data flash (flash memory), and the like. In order to control each part of the vehicle 1, the vehicle 1 is equipped with a plurality of ECUs, and each ECU is connected so as to be capable of bidirectional communication using a CAN (Controller Area Network) communication protocol. The plurality of ECUs include an E / TECU 41 for controlling the engine 2, the torque converter 3 and the continuously variable transmission 4, and an IDSECU 42 for IDS (idling stop) control.

  Various sensors necessary for control are connected to the E / TECU 41 and the IDSECU 42, respectively.

<Overview of IDS control>
IDS control is a technique for improving fuel consumption by suppressing idling of the engine 2. As information necessary for IDS control, information such as a vehicle speed and an operation amount of a brake pedal is input to IDSECU which is an ECU for IDS control.

  In the IDS control, when the brake pedal is operated (depressed) while the vehicle 1 is traveling, the IDSECU 42 determines whether or not a predetermined IDS start condition is satisfied. The IDS start condition is, for example, a condition that the vehicle speed is a predetermined idling stop execution vehicle speed (for example, 10 km / h) or less and the brake pedal is operated for a predetermined time or more. While the brake pedal is being operated, whether or not the IDS start condition is satisfied is determined at a constant cycle. When the IDS start condition is satisfied, an IDS request is transmitted from the IDSECU 42 to the E / TECU 41 in response to the IDS start condition being satisfied, and the engine 2 is stopped by the E / TECU 41 in response to the IDS request ( Idling stop).

  After the start of idling stop, the IDSECU 42 determines whether or not a predetermined IDS return condition is satisfied at a constant cycle. The IDS return condition is, for example, a condition that the operation of the brake pedal is released during the idling stop (the driver's foot is released from the brake pedal). When the IDS return condition is satisfied, an IDS return request is transmitted from the IDSECU 42 to the E / TECU 41. In response to the IDS return request, the starter is operated by the E / TECU 41 and the engine 2 is restarted.

<First clutch control>
FIG. 2 shows changes over time in the turbine speed NT, the input speed NIN, the engine speed, the ON / OFF state of the electric oil pump (EOP) 33 and the engaged / released state of the forward clutch C during the first clutch control. FIG.

  In parallel with the IDS control, the E / TECU 41 executes clutch control for controlling the engagement / release of the forward clutch C. The clutch control is executed when the first clutch control is executed when IDS is started after the vehicle 1 is stopped, and when IDS control is started while the vehicle 1 is traveling at a vehicle speed equal to or higher than a predetermined vehicle speed. Second clutch control.

  In the first clutch control, the engaged state of the forward clutch C is maintained even after the start of the IDS control (time T11).

  As the rotational speed of the engine 2 (engine rotational speed) decreases, the hydraulic pressure generated by the mechanical oil pump 32 decreases. In the first clutch control, it is determined whether or not the engine speed has been acquired and the engine speed has decreased to a predetermined speed. The vehicle 1 is provided with an engine rotation sensor that outputs a pulse signal synchronized with the rotation of the engine 2 (rotation of the crankshaft) as a detection signal, and the engine speed is acquired from the detection signal of the engine rotation sensor. be able to. The predetermined rotational speed is a rotational speed that requires driving of the electric oil pump 33. For example, the predetermined rotational speed is slightly higher than the upper limit value of the engine rotational speed at which the engagement of the forward clutch C cannot be maintained by the hydraulic pressure generated by the mechanical oil pump 32. The speed is set.

  When the engine speed decreases to a predetermined speed, the electric oil pump 33 is turned on (time T12). When the electric oil pump 33 is turned on, the electric oil pump 33 generates a hydraulic pressure, and the generated hydraulic pressure is supplied to the forward clutch C, whereby the forward clutch C is kept engaged.

<Second clutch control>
FIG. 3 shows time changes of the turbine rotational speed NT, the input rotational speed NIN, the engine rotational speed, the on / off state of the electric oil pump (EOP) 33, and the engaged / released state of the forward clutch C during the second clutch control. FIG.

  In the second clutch control, the forward clutch C is released in response to the start of IDS control (time T21).

  Thereafter, the turbine rotational speed NT that is the rotational speed of the turbine runner of the torque converter 3 is acquired. The vehicle 1 is provided with a turbine rotation sensor that outputs a pulse signal synchronized with the rotation of the turbine runner as a detection signal, and the turbine rotation speed NT can be obtained from the detection signal of the turbine rotation sensor.

  Further, the input rotational speed NIN that is the rotational speed of the input shaft 11 of the continuously variable transmission 4 is acquired. The vehicle 1 is provided with an input shaft rotation sensor that outputs a pulse signal synchronized with the rotation of the input shaft 11 as a detection signal, and the input rotation speed NIN can be obtained from the detection signal of the input shaft rotation sensor. it can.

  Then, it is determined whether or not both the turbine rotational speed NT and the input rotational speed NIN have decreased below a predetermined value. While at least one of the turbine rotational speed NT and the input rotational speed NIN is larger than a predetermined value, the turbine rotational speed NT and the input rotational speed NIN are repeatedly acquired.

  The predetermined value is preferably 0, but may not be 0 as long as the value is sufficiently small such that the turbine speed NT and the input speed NIN are substantially equal.

  When both the turbine rotational speed NT and the input rotational speed NIN are reduced to a predetermined value or less (time T22), there is no reason to release the forward clutch C (the concern about belt slip due to inertia braking due to sudden braking). In order to engage, the electric oil pump 33 is turned on (time T22). When the electric oil pump 33 is turned on, the electric oil pump 33 generates hydraulic pressure, and the generated hydraulic pressure is supplied to the forward clutch C, whereby the forward clutch C is engaged.

<Permitted or not to execute IDS control>
FIG. 4 is a table for explaining permission and prohibition of execution of IDS control according to the IDS control mode.

  Since the IDS control and the first clutch control or the second clutch control are executed in parallel, the IDS control includes the first mode executed in parallel with the first clutch control and the second clutch control. There are two modes, the second mode being executed. A condition for setting permission or prohibition of execution of IDS control is provided for each mode.

  In the first clutch control, the engaged state of the forward clutch C is maintained regardless of the start of the IDS control. Therefore, in the first mode IDS control, the engine 2 is restarted while the forward clutch C remains engaged. Is done. Therefore, the first mode is a mode in which the engine 2 is restarted with the forward clutch C engaged.

  On the other hand, in the second clutch control, the forward clutch C is released in response to the start of the IDS control, and both the turbine rotational speed NT and the input rotational speed NIN are reduced to a predetermined value or less (the vehicle 1 is almost stopped). Accordingly, the electric oil pump 33 is turned on and the forward clutch C is engaged. Therefore, in the IDS control in the second mode, there are a case where the engine 2 is restarted with the forward clutch C released and a case where the engine 2 is restarted with the forward clutch C engaged.

  Further, when an abnormality occurs in the electric oil pump 33, there is a possibility that the electric oil pump 33 cannot generate a hydraulic pressure necessary for engaging the forward clutch C. Therefore, in the IDS control when the electric oil pump 33 is abnormal, the engine 2 is restarted when the forward clutch C is released and the engine 2 is engaged when the forward clutch C is engaged. May be restarted. Therefore, the IDS control in a state where an abnormality has occurred in the electric oil pump 33 is the IDS control in the second mode.

  In the cold state of the engine 2, the idling speed of the engine 2 is set high in order to increase engine stall resistance. When the engine 2 is restarted with the forward clutch C released, if the engine 2 is in a cold state, the engine rotation may be blown up before the forward clutch C is engaged. When the engine 2 is restarted with the forward clutch C engaged, even if the engine 2 is in a cold state, the forward clutch C is engaged, so there is no possibility that the engine rotation will blow up.

  Therefore, the execution of the IDS control in the second mode is prohibited until the engine water temperature rises to a second temperature that is higher than the IDS control in the first mode, and the IDS control in the first mode is more effective than the IDS control in the second mode. The engine water temperature condition for setting permission or prohibition of execution of IDS control is switched between the first mode and the second mode so that the execution is permitted at the first temperature at which the engine water temperature is low. That is, the IDS control in the second mode is prohibited when the engine water temperature is lower than the second temperature, and the IDS control in the first mode is permitted when the engine water temperature is equal to or higher than the first temperature lower than the second temperature. . The engine water temperature can be acquired from the detection signal of the engine water temperature sensor that detects the temperature of the cooling water flowing through the engine 2 (engine water temperature).

  Thus, the IDS control in the second mode is prohibited when the engine water temperature is lower than the second temperature, and the IDS control in the first mode is permitted at the first temperature or higher where the engine water temperature is lower than the second temperature. As a result, the startability (driving force) at the restart of the engine 2 can be stabilized, and the IDS control in the first mode can be executed from the state in which the engine 2 is cooled. The effect of improving the fuel consumption can be obtained by executing the above.

  Further, in the second mode IDS control, when the engine 2 is restarted with the forward clutch C released, the forward clutch C needs to be engaged. In this case, if air is contained in the piston chamber (hydraulic chamber) 28 of the secondary pulley 15 of the continuously variable transmission 4, the rise of the hydraulic pressure (sheave pressure) in the piston chamber 28 is delayed, and accordingly, the forward clutch C Engagement may be delayed. In other words, the forward clutch C is engaged after the hydraulic pressure in the piston chamber 28 has increased to a pinching pressure that does not cause belt slipping, so that the rise of the hydraulic pressure in the piston chamber 28 is delayed because air is contained in the piston chamber 28. As a result, the engagement of the forward clutch C is delayed. If the engagement of the forward clutch C is delayed, the startability (acceleration performance) of the vehicle 1 is reduced, or the turbine rotation of the torque converter 3 is blown up with a time lag from the restart of the engine 2 to the engagement of the forward clutch C. In addition, a shock may occur when the forward clutch C is engaged.

  Therefore, the execution of the IDS control in the second mode is prohibited until the second time, in which the running time after the start switch (ignition switch) of the vehicle 1 is turned on, is longer than the IDS control in the first mode. The IDS control in the 1 mode is an IDS control so that the execution is permitted when the traveling time after the start switch of the vehicle 1 is turned on, which is shorter than the IDS control in the second mode, reaches the first time. The travel time condition for setting permission or prohibition of execution is switched between the first mode and the second mode. That is, the IDS control in the second mode is prohibited when the running time after the start switch of the vehicle 1 is turned on is less than the second time, and the IDS control in the first mode is prohibited when the start switch of the vehicle 1 is on. When the running time after being made becomes the first time shorter than the second time, it is permitted.

  While the engine 2 is stopped by the IDS control in the first mode, the electric oil pump 33 operates and the hydraulic pressure is supplied to the piston chamber 28 of the secondary pulley 15, so there is a concern that air will enter the piston chamber 28. Absent.

<Effect>
As described above, the IDS control in the second mode is prohibited when the running time after the start switch of the vehicle 1 is turned on is less than the second time. Therefore, air can be excluded from the piston chamber 28 of the secondary pulley 15 before the execution of the IDS control in the second mode is permitted. Therefore, the time lag of engagement of the forward clutch C and the occurrence of shock can be suppressed. On the other hand, since the IDS control in the first mode can be executed at an early stage, it is possible to obtain the effect of improving the fuel consumption by executing the IDS control in the first mode.

  Since the travel distance increases as the travel time of the vehicle 1 increases, the travel time condition may be replaced with the travel distance condition. Specifically, the IDS control in the second mode is prohibited when the travel distance after the start switch of the vehicle 1 is turned on is less than the second distance, and the start switch of the vehicle 1 is turned on in the IDS control in the first mode. The travel distance after being made may be permitted at a first distance that is shorter than the second distance.

  Further, both the travel time condition and the travel distance condition may be adopted. Specifically, the IDS control in the second mode is prohibited when the travel time after the start switch of the vehicle 1 is turned on is less than the second time or the travel distance is less than the second distance, and the IDS control in the first mode is The travel time after the start switch of the vehicle 1 is turned on may be permitted for a first time that is shorter than the second time or a first distance that is shorter than the second distance.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-described embodiment, the continuously variable transmission 4 is taken up, but the control device according to the present invention can also be used for a stepped automatic transmission (AT). The control device according to the present invention can also be used in a power split type continuously variable transmission. The power split type continuously variable transmission includes a belt-type continuously variable transmission mechanism that continuously changes power by changing a transmission ratio, and a constant transmission mechanism that changes power at a constant transmission ratio. Is a transmission that can be divided into two systems for transmission.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Vehicle 2: Engine 4: Continuously variable transmission 41: E / TECU (control device, IDS control means, permission / rejection setting means)
C: Forward clutch (friction engagement element)

Claims (1)

Engine, belt-type continuously variable transmission for shifting power transmitted from the engine to wheels, and friction engagement elements engaged / released to transmit / cut off power between the engine and the wheels A control device used in a vehicle equipped with
IDS control means for executing IDS control for stopping the engine in response to establishment of an IDS start condition and restarting the engine in response to establishment of an IDS return condition;
Permission / denial setting means for setting permission and / or prohibition of execution of the IDS control,
The IDS control includes a first mode in which the engine is restarted with the friction engagement element engaged, and the friction engagement element between the satisfaction of the IDS start condition and the satisfaction of the IDS return condition. And a second mode for releasing
The permission / rejection setting unit switches a condition relating to at least one of a travel time or a travel distance of the vehicle for the setting between the first mode and the second mode.

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