JP5949376B2 - Powertrain system control method and powertrain system - Google Patents

Description

  The present invention relates to a control method for a powertrain system and a powertrain system of a vehicle such as an automobile, particularly a vehicle in which a fluid transmission device is disposed between an engine and a transmission mechanism, and a catalyst device is disposed in an exhaust passage of the engine. In the field of control technology for vehicle powertrain systems.

  Conventionally, in a vehicle such as an automobile, a catalyst device (three-way catalyst) is installed in an exhaust passage of an engine in order to remove harmful components in exhaust gas. Here, the catalyst device does not function when the temperature is low, and it is necessary to quickly increase the temperature and activate it when the engine is cold-started. Therefore, a technology has been put into practical use that performs so-called idle-up control that raises the idling speed when the engine is cold started, exhausts hot exhaust gas, and quickly raises the temperature of the catalyst device.

  However, in a stepped or continuously variable automatic transmission in which a fluid transmission device (torque converter) is disposed between the engine and the speed change mechanism, when the idle up control is performed in the travel range such as the D range, the creep force is reduced. There is a possibility that the vehicle will overcome the braking force generated by the driver's depression of the brake pedal before the vehicle starts running, and the vehicle may start unexpectedly. Therefore, conventionally, the early activation control of the catalyst device by the idle-up control at the cold start is performed only in the non-traveling range such as the P range and the N range, and is finished when the driver operates the traveling range. I was doing.

  On the other hand, in order to respond to the recent tightening of exhaust gas regulations, it is required to shorten the activation time of the catalyst device, and for that purpose, the idle-up control is interrupted when shifting from the non-traveling range to the traveling range. In addition, it is conceivable to perform the idle-up control after the shift to the traveling range while suppressing the creep force.

  Therefore, the following methods have been studied as a method for suppressing the creep force in the travel range.

  First, the shift lever of the automatic transmission remains in the traveling range, and the starting friction element is released in the traveling range as disclosed in Patent Document 1 by releasing the starting friction element and setting the transmission mechanism in a neutral state. A method of slipping the friction element for use (so-called neutral idle control) and a method of setting the speed change mechanism in an interlock state are conceivable.

  However, in the method of setting the speed change mechanism to the neutral state in the traveling range, when the brake is released and the vehicle starts, the hydraulic pressure is supplied to the starting friction element and the friction element is fastened. There is a time lag between releasing and depressing the accelerator pedal before starting. That is, the start response is deteriorated.

  Further, in the neutral idle state, the engine load is smaller than in the interlock state, so that the catalyst device can be activated earlier. In other words, the smaller the engine load, the smaller the force that pushes down the piston of the engine, so that the engine can be combusted that is advantageous for activating the catalyst device.

  For this reason, when shifting from the non-traveling range to the traveling range, an attempt is made to select a neutral idle state that is more advantageous in terms of activation of the catalyst device. However, when switching from the non-traveling range to the traveling range, the starting frictional element is controlled from the released state to the slipped state, but especially when cold, the viscosity of ATF (automatic transmission fluid) is large, It is difficult to raise the hydraulic pressure and control it to a hydraulic pressure that achieves a predetermined slip condition with high accuracy. If the hydraulic pressure cannot be controlled with high accuracy, the starting frictional element will be fastened and there is a possibility of starting unexpectedly.

JP 2008-213590 A

  Therefore, the present invention provides a vehicle powertrain system in which a fluid transmission device is disposed between an engine and a transmission mechanism, and a catalyst device is disposed in an exhaust passage of the engine. It is an object of the present invention to make it possible to satisfactorily perform idle-up control in the travel range without deteriorating start response or unintentional start in order to promote activation of the catalyst device during activation.

  In order to solve the above-mentioned problems, a powertrain system control method and a powertrain system according to the present invention are configured as follows.

First, the invention according to claim 1 of the present application is
Engine,
A catalyst device disposed on an exhaust path of the engine;
An automatic transmission having a transmission mechanism and a fluid transmission device provided on a power transmission path from the engine to the transmission mechanism;
A control device for controlling the engine and the automatic transmission;
A powertrain system control method comprising:
When the catalyst device is in an inactive state during idle operation of the engine, the step of increasing the idle speed of the engine compared to when in the active state;
During the execution of the step, when the automatic transmission is switched from the non-traveling range to the traveling range in a state in which there is a braking request from the driver, the starting friction element in the transmission mechanism of the automatic transmission is fastened. And realizing an interlock state of the transmission mechanism by fastening a predetermined friction element;
After realizing the interlock state in the step, when there is a request for activating the catalyst device and a braking request by the driver, the automatic transmission is moved by moving the starting friction element to the release side. Realizing the neutral idle state of
It is characterized by having.

The invention according to claim 2 of the present application is the invention according to claim 1,
Furthermore,
During achieve an interlock state of the automatic transmission, when the there is the driver of the start request, the steps of starting the vehicles to release the interlocking condition,
When there is a braking request from the driver in the stop state of the vehicle after the step, control for realizing a neutral idle state of the automatic transmission is performed by shifting the starting friction element to the release side. Steps to do,
It is characterized by having.

Furthermore, the invention according to claim 3 of the present application is
Engine,
A catalyst device disposed on an exhaust path of the engine;
An automatic transmission having a transmission mechanism and a fluid transmission device provided on a power transmission path from the engine to the transmission mechanism;
A control device for controlling the engine and the automatic transmission;
A powertrain system with
The controller is
During idle operation of the engine, when the catalyst device is in an inactive state, the idling speed of the engine is increased compared to when in the active state,
When the automatic transmission is switched from the non-traveling range to the traveling range while the engine is idling at a high speed and there is a braking request from the driver, the automatic transmission starts in the transmission mechanism. When fastening the friction element, the interlocking state of the transmission mechanism is realized by fastening a predetermined friction element,
After realizing the interlock state, when there is a request to activate the catalyst device and a braking request by the driver, the starting frictional element is shifted to the release side, thereby neutralizing the automatic transmission. It is characterized by realizing an idle state.

  With the above configuration, according to the invention according to each claim of the present application, the following effects can be obtained.

  First, the invention according to claim 1 controls the hydraulic pressure of the starting friction element from the engaged state to the release side in order to shift to the neutral idle state after realizing the interlock state. This is easier than the hydraulic control from the release side to the fastening side that directly shifts from the neutral state to the neutral idle state.

  This is because control from the engaged state to the release side is relatively easy since it is release from the state where the engagement hydraulic chamber is full of ATF, but control from the release state to the engagement side is relatively easy. This is because precharge control is performed from the state in which the ATF is hardly filled in the chamber, the ATF is filled and the friction element is fastened, so that the control is relatively difficult. In particular, when the ATF viscosity is cold, it is more difficult to perform this control with high accuracy, and the starting frictional element is fastened, which may cause the vehicle to start unexpectedly.

  Therefore, according to the first aspect of the invention, even during cold start when the viscosity of the ATF is large, the neutral idle state that is advantageous for the activation of the catalyst device is achieved while preventing the vehicle from starting unexpectedly. Can be controlled.

  In addition, the stop in the travel range after traveling is performed, for example, when stopping at a signal wait, and it is assumed that the vehicle stops for a while, for example, when stopping from the non-travel range to the travel range, This is done when leaving the parking lot, etc. It is assumed that it is done when the driver intends to start. Therefore, the driver's start request tends to be higher when the vehicle stops when switching from the non-travel range to the travel range than when the vehicle stops in the travel range after travel.

On the other hand, regarding the startability of an actual vehicle, the interlock control in which the starting frictional engagement element is fastened is more effective when the speed change mechanism is started than the neutral idle control in which the starting frictional element is in the slip state. Since it is close to the state of, it has better startability.

  Therefore, when the non-traveling range is switched to the traveling range, the interlock control that is advantageous in terms of the startability of the vehicle can meet the high start request of the driver. On the other hand, when the vehicle is stopped in the travel range after traveling, the driver's start request is not high, so that the neutral idle control can be selected by giving priority to the activation of the catalyst device over the startability of the vehicle.

  As described above, according to the second aspect of the present invention, when the vehicle travels after the interlock state and then stops, the transmission mechanism is shifted from the non-travel range to the travel range to shift to the neutral idle state. It is possible to ensure both startability when switching and early activation of the catalyst device.

  Finally, according to the invention of claim 3, the same effect as that of the method of the invention according to claim 1 can be obtained in the powertrain system.

1 is a skeleton diagram of an automatic transmission (stepped transmission) according to a first embodiment of the present invention. It is a table | surface which shows the relationship between the combination of the fastening of the friction element which comprises the automatic transmission in 1st Embodiment, and a gear stage, an interlock, and a neutral idle. It is a block diagram which shows the structure of the control apparatus in 1st Embodiment. It is a flowchart which shows operation | movement of the powertrain system in 1st Embodiment. It is a flowchart which shows the operation | movement at the time of the interlock control of the powertrain system in 1st Embodiment. It is a flowchart which shows the operation | movement at the time of neutral idle control of the powertrain system in 1st Embodiment. It is a time chart which shows the state of an engine and an automatic transmission at the time of operation of N-> D (interlock)-> N in a 1st embodiment. It is a time chart which shows the state of an engine and an automatic transmission at the time of operation of N-> D (interlock)-> start in a 1st embodiment. 6 is a time chart showing the state of the engine and the automatic transmission during an operation of D (neutral idle) → start in the first embodiment. It is a flowchart which shows the operation | movement at the time of neutral idle control of the powertrain system in the modification of 1st Embodiment. It is a time chart which shows the state of the engine and automatic transmission at the time of operation of D (neutral idle)-> start in the modification of a 1st embodiment. It is a flowchart which shows operation | movement of the powertrain system in 2nd Embodiment. It is a flowchart which shows the operation | movement at the time of the interlock control of the powertrain system in 2nd Embodiment. It is a flowchart which shows the operation | movement at the time of neutral idle control of the powertrain system in 2nd Embodiment. It is a time chart which shows the state of the engine and automatic transmission at the time of operation of N-> D (interlock)-> D (neutral idle)-> start in a 2nd embodiment. It is a skeleton diagram of an automatic transmission (continuously variable transmission) in a third embodiment according to the present invention. It is a table | surface which shows the relationship between the combination of the fastening of the friction element which comprises the automatic transmission in 3rd Embodiment, a front reverse range, an interlock, and a neutral idle. It is a block diagram which shows the structure of the control apparatus in 3rd Embodiment. It is a flowchart which shows operation | movement of the powertrain system in 3rd Embodiment. It is a flowchart which shows the operation | movement at the time of the interlock control of the powertrain system in 3rd Embodiment. It is a flowchart which shows the operation | movement at the time of neutral idle control of the powertrain system in 3rd Embodiment. It is a time chart which shows the state of an engine and an automatic transmission at the time of operation of N-> D (interlock)-> N in a 3rd embodiment. It is a time chart which shows the state of an engine and an automatic transmission at the time of operation of N-> D (interlock)-> start in a 3rd embodiment. It is a time chart which shows the state of the engine and automatic transmission at the time of operation of D (neutral idle)-> start in a 3rd embodiment. It is a flowchart which shows operation | movement of the powertrain system in 4th Embodiment. It is a flowchart which shows the operation | movement at the time of the interlock control of the powertrain system in 4th Embodiment. It is a flowchart which shows the operation | movement at the time of neutral idle control of the powertrain system in 4th Embodiment. It is a time chart which shows the state of the engine and automatic transmission at the time of operation of N-> D (interlock)-> D (neutral idle)-> start in a 4th embodiment.

  Hereinafter, a control method of a powertrain system and an embodiment of a powertrain system according to the present invention, when a stepped transmission is provided as an automatic transmission constituting the system (first embodiment, the first embodiment) And a case where a continuously variable transmission is provided (third embodiment and fourth embodiment).

(About the first embodiment)
A vehicle powertrain system to which a first embodiment of the present invention is applied will be described. This powertrain system is applied to a front engine, a front drive vehicle, etc., and has a horizontally installed engine (not shown) and a planetary gear type stepped transmission (hereinafter referred to as “automatic transmission”) as an automatic transmission. 1) and a controller 100 that controls the engine and the automatic transmission 1, and a catalyst device (for removing harmful components in the exhaust gas) on the exhaust path of the engine. (Not shown) is provided.

  FIG. 1 is a skeleton diagram showing the configuration of an automatic transmission 1 that constitutes the powertrain system. As shown in FIG. 1, the automatic transmission 1 is applied to a horizontal engine type vehicle such as a front engine front drive vehicle, and includes a torque converter 3 attached to an engine output shaft 2 as main components. A transmission mechanism 5 to which the output rotation of the torque converter 3 is input via the input shaft 4, and the transmission case 5 is disposed on the shaft center of the input shaft 4. It is stored.

  Then, the output rotation of the transmission mechanism 5 is transmitted to the differential device 9 via the counter drive mechanism 8 from the output gear 7 which is also disposed in the intermediate portion of the input shaft 4 on the axis of the input shaft 4. The left and right axles 9a and 9b are driven.

  The torque converter 3 includes a case 3a connected to the engine output shaft 2, a pump 3b fixed in the case 3a, and opposed to the pump 3b and driven by the pump 3b via hydraulic oil. A turbine 3c, a stator 3e interposed between the pump 3b and the turbine 3c and supported by the transmission case 6 via a one-way clutch 3d to increase torque, and the case 3a and the turbine 3c, and a lock-up clutch 3f that directly connects the engine output shaft 2 and the turbine 3c via the case 3a. Then, the rotation of the turbine 3 c is transmitted to the transmission mechanism 5 through the input shaft 4.

  On the other hand, the transmission mechanism 5 includes first, second, and third planetary gear sets (hereinafter, simply referred to as “first, second, and third gear sets”) 10, 20, and 30, which are included in the transmission case 6. Are arranged in order from the torque converter side on the counter-torque converter side of the output gear 7.

  Further, as a friction element constituting the speed change mechanism 5, a first clutch 40 (starting friction element) and a second clutch 50 are disposed on the torque converter side of the output gear 7, and the counter torque of the output gear 7 is provided. On the converter side, a first brake 60, a second brake 70, and a third brake 80 are sequentially arranged from the torque converter side.

  Each of the first, second, and third gear sets 10, 20, and 30 is a single pinion type planetary gear set, and is engaged with the sun gears 11, 21, and 31 and the sun gears 11, 21, and 31, respectively. A plurality of pinions 12, 22, 32, carriers 13, 23, 33 that respectively support these pinions 12, 22, 32, and ring gears 14, 24, 34 that mesh with the pinions 12, 22, 32, respectively. ing.

  The input shaft 4 is connected to the sun gear 31 of the third gear set 30, the sun gear 11 of the first gear set 10, the sun gear 21 of the second gear set 20, the ring gear 14 of the first gear set 10, and the second gear set 20. The carrier 23, the ring gear 24 of the second gear set 20, and the carrier 33 of the third gear set 30 are connected to each other. The output gear 7 is connected to the carrier 13 of the first gear set 10.

  Further, the sun gear 11 of the first gear set 10 and the sun gear 21 of the second gear set 20 are connected to the input shaft 4 through the first clutch 40 so as to be connectable and detachable, and the carrier 23 of the second gear set 20 is The input shaft 4 is connected to the input shaft 4 via the second clutch 50 so as to be connected and disconnected.

  Further, the ring gear 14 of the first gear set 10 and the carrier 23 of the second gear set 20 are connected to the transmission case 6 via the first brake 60 arranged in parallel so as to be connectable and disconnectable. The ring gear 24 of the third gear set 30 and the carrier 33 of the third gear set 30 are connected to the transmission case 6 via the second brake 70 so that they can be connected and disconnected, and the ring gear 34 of the third gear set 30 is connected to the third brake 30. The transmission case 6 is connected to the transmission case 6 via 80.

  With the above-described configuration, according to the speed change mechanism 5, the forward 6 speed and the reverse speed are obtained by combining the engagement states of the first and second clutches 40 and 50 and the first, second, and third brakes 60, 70, and 80. The relationship between the combination and the gear position will be described below with reference to FIG.

  FIG. 2 is a table showing the relationship between the engagement combinations of the friction elements of the automatic transmission 1 and the shift speed (the blank portion indicates that the friction elements are released). As shown in FIG. 2, the first clutch 40 is engaged at the first speed, the second speed, the third speed, and the fourth speed, and the second clutch 50 is engaged at the fourth speed, the fifth speed, and the sixth speed. 60 is fastened at the first speed and reverse speed, the second brake 70 is fastened at the second speed and sixth speed, and the third brake 80 is fastened at the third speed, fifth speed and reverse speed.

  On the other hand, FIG. 2 also shows a combination of engagement of friction elements during interlock control and neutral idle control of the automatic transmission 1 according to the present embodiment.

  First, in the present embodiment, when the vehicle stops in the travel range immediately after the cold start of the engine, that is, the brake pedal is depressed, a non-travel range such as the P range or N range (hereinafter referred to as “N range”). The first clutch that is engaged at the first speed as shown in the table of FIG. 2 when the driving range such as the D range is selected (hereinafter referred to as “D range”) and the vehicle is stopped at the first gear position. By engaging the 40 and the first brake 60, and simultaneously engaging the second brake 70, an interlock control is performed so that the output gear 7 of the speed change mechanism 5 cannot rotate, so-called an interlock state. Note that the interlock state can be realized by engaging only the first brake 60 and the second brake 70 while the first clutch 40 is released.

  Here, the principle that the transmission mechanism 5 enters the interlock state when the first brake 60 and the second brake 70 are engaged will be described below.

  When the first brake 60 is engaged, the pinion 22 of the second gear set 20 is fixed, and when the second brake 70 is engaged, the ring gear 24 of the second gear set 20 is fixed, so that the sun gear 21 of the second gear set 20 is In addition to being fixed, the sun gear 11 of the first gear set 10 connected to the sun gear 21 is also fixed. Further, since the ring gear 14 of the first gear set 10 is also fixed by the engagement of the first brake 60, the output gear 7 connected to the carrier 13 of the first gear set 10 is also unable to rotate, and the transmission mechanism 5 is in the interlocked state. Become.

  Therefore, in the present embodiment in which the first clutch 40 is further engaged, the sun gears 11 and 21 are fixed as described above, so that not only the output gear 7 of the speed change mechanism 5 but also the input shaft 4 is fixed.

  Further, in the present embodiment, the accelerator pedal is released and the brake pedal is depressed when the catalyst device is still in an inactive state after traveling and stops in the D range, that is, with the D range selected. When the vehicle stops at the first speed, as shown in the table of FIG. 2, the first brake 60 is engaged and the engagement force of the first clutch 40 that is engaged at the first speed is reduced to slip. Thus, neutral idle control is performed to place the transmission mechanism 5 in the neutral idle state. In this embodiment, the second brake 70 is simultaneously engaged.

  Although the second brake 70 is described as being simultaneously engaged when performing the neutral idle control, the second brake 70 may be left released. However, since the interlock state is established by engaging the first brake 60 and the second brake 70, the output gear 7 and the axles 9a and 9b are fixed. Therefore, the first clutch when starting from the neutral idle state Forty engagement shocks are alleviated, and a so-called hill hold function is obtained during neutral idle control on an uphill / downhill road.

  Then, through the interlock control and the neutral idle control as described above, the transmission mechanism 5 is idled in a desired state, that is, a state where no power is output even when the engine speed is increased, and high-temperature exhaust gas is discharged. Thus, activation of the catalyst device is promoted.

  Next, a control device for controlling the powertrain system according to the first embodiment will be described in detail with reference to FIG.

  FIG. 3 is a block diagram illustrating a configuration of the control device according to the first embodiment. As shown in FIG. 3, the automatic transmission 1 has a hydraulic circuit 110 for selectively supplying a line pressure for engagement to the clutches 40 and 50 and the brakes 60, 70, and 80 to realize the shift stage. The circuit 110 is provided with a solenoid valve 110a for speed change control.

  Further, a controller 100 is provided to control these solenoid valves 110a. The controller 100 detects a signal from a range sensor 101 that detects a range selected by a driver's operation, a signal from a vehicle speed sensor 102 that detects the vehicle speed of the vehicle, and a driver's accelerator pedal operation amount. A signal from the accelerator sensor 103 that performs the operation, a signal from the brake pressure sensor 104 that detects the brake pedal operation amount of the driver, a signal from the engine rotation speed sensor 105 that detects the rotation speed of the engine output shaft 2, and the turbine 3c. A signal from the turbine rotation speed sensor 106 for detecting the rotation speed (that is, the rotation speed of the input shaft 4), a signal from the hydraulic pressure sensor 107 for sensing the engagement state of the friction element, and the like are input from the controller 100. A control signal is output to each solenoid valve 110a of the hydraulic circuit 110 based on the input signal.

  Thereby, the opening / closing or opening degree of each solenoid valve 110a is controlled according to the selected range and the driving state of the vehicle, and the line pressure is selectively supplied to the clutches 40, 50 and the brakes 60, 70, 80, According to the table of FIG. 2, each gear stage, interlock, and neutral idle state are realized.

  Next, the control method of the powertrain system according to the first embodiment will be described in detail according to the flowcharts of FIGS.

  FIGS. 4 to 6 are flowcharts showing specific operations of the powertrain system when performing idle-up control after engine startup in the first embodiment. That is, FIG. 4 shows the main routine of idle up control, FIG. 5 shows the details of the interlock control which is a subroutine included in FIG. 4, and FIG. 6 shows the neutral idle control which is a subroutine included in FIG. (In some drawings, the neutral idol is displayed as “N-idle”).

  First, the specific operation of the engine idle-up control including the interlock control and the like by the controller 100 will be described with reference to the flowchart of FIG.

  The controller 100 starts the control operation when the ignition switch of the engine is turned on while the range of the automatic transmission 1 is in the P range. First, in step S1, signals from the sensors 101 to 107 shown in FIG. 3 are input, and then in step S2, a control signal is sent to the hydraulic circuit 110 so as to engage the first brake 60 that is engaged in the P range. Output.

  Next, in step S3, it is determined from the signal from the vehicle speed sensor 102 whether or not the vehicle is stopped (vehicle speed is 0 km / h). When it is determined that the vehicle is stopped, it is determined in step S4 whether or not there is an idle up request for increasing the engine idle speed.

  Here, the idle-up request is required to be activated early when the temperature of the catalyst device indicated by the signal from the catalyst temperature sensor (not shown) does not rise to the activation temperature of the catalyst device. It is determined that there is an idle up request. Since the temperature of the catalyst device increases with the elapsed time after the engine is started, it may be determined whether there is an idle up request based on the elapsed time.

  Since it is determined that the catalyst temperature is low immediately after the engine is started and there is an idle-up request, the controller 100 next determines in step S5 whether or not the range was the D range at the time of stop determination in step S3. judge.

  Further, since the range immediately after the start of the engine is the P range, it is determined in step S5 that the stop range is not the D range, and then in step S6, it is determined whether the current range is the R range. . When it is determined that the current range is not the R range, that is, the P range, idle up is performed in step S7. As a result, after the engine is started, idle-up is performed in the state of the P range before the start of traveling, and activation of the catalyst device is promoted. On the other hand, if it is determined in step S6 that it is the R range, idle up is prohibited (terminated) in step S8.

  Next, in step S9, it is determined whether or not the range is the N range (including the P range) at the time of the stop determination in step S4, and the range immediately after the engine is started is the P range. It determines with YES.

  Thereafter, in step S10, it is determined whether or not an ND operation has been performed from the signal of the range sensor 101, that is, whether or not a shift operation has been performed from the N range (P range) to the D range by the driver. -Continue to idle up in the P range until it is determined that the D operation has been performed.

  Here, when the ND operation is performed while performing the idle up in the P range state, it is determined in step S10 that the ND operation has been performed, and the idle up is continued in the D range state. . At this time, it is determined in step S11 based on the signal from the brake pressure sensor 104 whether the brake pedal is depressed by the driver, that is, whether the brake is ON. Interlock control described later is executed. On the other hand, when it is determined in step S11 that the brake is not ON, it is considered that the driver has no intention to brake, and in order to start the vehicle, the first clutch 40 is engaged in step S12, and in step S13. , Idle up is prohibited.

  On the other hand, when it is determined that the catalyst device is still in an inactive state and there is an idle up request in step S4 when the vehicle is stopped after traveling, the vehicle is in the D range at the time of stopping, so in step S5. In step S15, it is determined whether or not the brake is ON based on the signal from the brake pressure sensor 104. If it is determined in step S15 that the brake is ON, the process proceeds to step S16. When neutral idle control, which will be described later, is executed and it is determined in step S15 that the brake is not ON, idle-up is prohibited.

  Next, the operation during the interlock control will be described with reference to FIG.

  First, the controller 100 engages the second brake 70 in step S21 and outputs a control signal to the hydraulic circuit 110 so that the first clutch 40 is engaged with a predetermined reduced oil pressure in step S22. As a result, the transmission mechanism 5 is in the interlock state. While the brake pedal is depressed without performing a shift operation in this interlock state, idling up is continued. The predetermined reduced hydraulic pressure is a hydraulic pressure that securely engages the clutch, but is lower than a normal hydraulic pressure that is an engaging hydraulic pressure capable of transmitting a torque necessary for traveling.

  If the brake pedal is not depressed in the D range (brake OFF), it is determined in step S23 that the brake pedal is not in the N range, in step S24 it is determined that the brake is OFF, and in step S25, the idle is increased. finish. Thereby, the idle up in D range is complete | finished.

  Next, in step S26, the first clutch 40 is engaged with the normal hydraulic pressure, and in step S27, a control signal is output to the hydraulic circuit 110 so as to release the second brake 70. Thereafter, when the first clutch 40 is actually engaged and the second brake 70 is released, the transmission mechanism 5 is released from the interlock state, and the automatic transmission 1 enters the first speed state.

  Next, in step S28, based on the signal from the vehicle speed sensor 102, it is determined whether or not the vehicle has reached a predetermined vehicle speed (for example, 3 km / h) or more. Then, the neutral idle execution condition flag is set (ON), and the process returns to the main routine of FIG.

  On the other hand, when the driver performs a shift operation to the N range in the interlock state, it is determined in the step S23 that the vehicle is in the N range. In step S30, the first clutch 40 is released, and in step S31. Then, a control signal is output to the hydraulic circuit 110 so as to release the second brake 70. As a result, the hydraulic pressure is simultaneously discharged from both friction elements by the hydraulic circuit 110, the transmission mechanism 5 is released from the interlock state, and the automatic transmission 1 enters the N range state, but continues to idle up. Thereafter, the process returns to the main routine of FIG.

  According to the above interlock control, the driver has braked off because the first clutch 40, which is the starting friction element, is already engaged with the oil pressure increased to a reduced oil pressure while the vehicle is stopped in the D range. At this time, the hydraulic pressure of the starting friction element can be quickly increased to the normal hydraulic pressure, and the start response is not deteriorated. Further, since the transmission mechanism 5 is in an interlock state during the idle up and the creep force is suppressed, the creep force increases, and before the start of traveling, the braking force due to the depression of the driver's brake pedal is overcome, There is no risk that the vehicle will start unintentionally.

  Next, the operation at the neutral idle control will be described with reference to FIG.

  First, in step S41, it is determined whether or not the flag is ON. However, since the vehicle has once traveled and the flag is set in step S33, it is determined in step S41 that the flag is ON. Next, in step S42, the second brake 70 is engaged, and in step S43, the transmission mechanism 5 is in a neutral idle state, that is, a hydraulic circuit that reduces the hydraulic pressure supplied to the first clutch 40 to a slip state. A control signal is output to 110.

  As a result, if the speed change mechanism 5 operates normally, it enters the neutral idle state and the interlock state. However, for confirmation, in step S44, the speed change mechanism 5 determines whether the interlock is actually completed. When it is determined that it has been completed, idle up is performed in step S45.

  The interlock completion determination is performed by, for example, providing a second brake pressure sensor that detects the hydraulic pressure supplied to the second brake 70, and inputting an output signal from the sensor to the controller 100, so that the second brake is detected. It may be determined that the interlock is established when the hydraulic pressure actually supplied to 70 reaches the normal hydraulic pressure. In addition, a hydraulic switch that is turned on when the hydraulic pressure supplied to the second brake 70 reaches a predetermined hydraulic pressure may be provided for determining the completion of the interlock.

  If the second brake 70 is not engaged due to some abnormality, for example, it is determined in step S44 that the interlock has not been completed, and the second brake 70 is engaged and the interlock is completed. The idle-up in step S45 is not performed. As a result, it is possible to reliably perform idle-up control in the interlock state, so that the engine rotates at a high speed in a state where the interlock is not established, and the vehicle starts against the driver's intention by a large creep force. The situation is avoided.

  Next, in step S46, it is determined whether or not the brake is OFF from the signal of the brake pressure sensor 104, that is, whether or not the driver has released the brake pedal. The idle-up control is continued while the mechanism 5 is in the neutral idle state and the interlock state.

  When the driver releases the brake pedal and determines in step S46 that the brake is OFF, the idle-up is terminated in step S47, the second brake 70 is released in step S48, and in step 49, the second brake 70 is released. A control signal is output to the hydraulic circuit 110 so that the one clutch 40 is engaged. As a result, the neutral idle state and the interlock state are released, and the transmission mechanism 5 enters the first speed state, and can start in response to the driver's depression of the accelerator pedal.

  Thereafter, in step S50, the neutral idle execution condition flag is canceled (OFF), and the process returns to the main routine of FIG.

  According to the above neutral idle control, while stopping in the D range, the first clutch 40, which is the starting friction element, is not completely released, and the idle state is increased to a certain level by increasing the hydraulic pressure. When the driver loosens the brake pedal, the hydraulic pressure of the starting friction element can be quickly raised to the normal hydraulic pressure, and both the driver's start request and early catalyst warm-up can be achieved.

  Next, FIG. 7 shows changes in various states (states of the engine, automatic transmission, etc.) of the vehicle when the vehicle to which the powertrain system according to the first embodiment is applied is operated by various methods. This will be described in detail according to the time chart of FIG.

  7 to 9 are time charts showing changes in various states of the vehicle at different driving operations. That is, FIG. 7 shows the N range → D range (interlock state) → N range operation, FIG. 8 shows the N range → D range (interlock state) → start operation, and FIG. (Neutral idle state) → Time charts at the time of starting operation are shown. In the following drawings, “first CL”, “first BR”, and “second BR” represent the first clutch 40, the first brake 60, and the second brake 70, respectively.

  As shown in the time chart of FIG. 7, even when the ND operation is performed immediately after the cold start of the engine and the operation for returning to the N range is performed, the transmission mechanism 5 is operated while the vehicle is stopped in the D range. It can lock up and idle up. Hereinafter, the time chart will be described in detail.

  In the initial N range, the brake is on and the vehicle is stopped, and the idle-up request is ON. Therefore, the engine is rotating at idle-up rotation, and only the first brake 60 of the transmission mechanism 5 is engaged. . At this time, since the first clutch 40 is disengaged, the turbine 3c as the input shaft 4 of the speed change mechanism 5 rotates and rotates at substantially the same speed as the engine rotation.

  Here, when there is an idle-up request and the driver performs an ND operation for brake ON (S10), interlock control is performed (S14).

  By performing the interlock control, the second brake 70 is engaged (S21), and the first clutch 40 is engaged with a predetermined reduced hydraulic pressure lower than the normal hydraulic pressure (S22), and the transmission mechanism 5 is in the interlock state. . At this time, the rotation of the turbine 3c is decelerated as the hydraulic pressure increases until the first clutch 40 is engaged.

  Next, when the driver performs an operation of returning from the D range to the N range (S23), the first clutch 40 and the second brake 70 are released (S30 and S31), and the interlock is released. At this time, since the first clutch 40 is released, the turbine rotation rises again.

  Therefore, for example, when the vehicle is temporarily shifted to the D range in order to start from the garage, but for some reason the start is stopped and returned to the N range, the transmission mechanism 5 is operated while the vehicle is stopped in the D range. By performing idle-up in the locked state, the idle-up control in the D range can be favorably performed without causing unintended start and the like in order to promote activation of the catalyst device.

  As shown in the time chart of FIG. 8, even when the engine is stopped for a while after the ND operation immediately after the cold start of the engine, the speed change mechanism is maintained while the vehicle stops until starting in the D range. 5 can be in an interlocked state while the first clutch 40 (starting friction element) is engaged, and idle up can be performed. Hereinafter, the time chart will be described in detail.

  The state from the initial stop in the N range to the interlock state in the D range is the same as in the case of FIG.

  Next, when the driver removes his / her foot from the brake pedal in the interlock state (S24), the idle-up is finished (S25), the first clutch hydraulic pressure increases from the reduced hydraulic pressure to the normal normal hydraulic pressure, and the first The two brakes 70 are released (S27), the interlock is released, the transmission mechanism 5 becomes the first speed, and the vehicle starts.

  In FIG. 8, when the speed change mechanism 5 changes from the interlock state to the first speed, the hydraulic pressure of the second brake 70 gradually decreases (see arrow a). This is to prevent the vehicle from starting suddenly by completely releasing the second brake 70 after waiting for the engine rotation that has been reduced to the predetermined rotation (see arrow b).

  When the vehicle speed exceeds the predetermined vehicle speed (S28), a neutral idle execution condition flag is set (S29).

  Therefore, for example, the catalyst device is activated by setting the transmission mechanism 5 in the interlocked state while engaging the first clutch 40 even during a slight stop time in the D range when starting from the garage. For promotion, idle up control in the D range can be performed satisfactorily without causing deterioration in start response or unintended start.

  As shown in the time chart of FIG. 9, the vehicle once traveled, but when the catalyst device is still in an inactive state and needs to be idled up, it is still in the D range until it starts again after it is temporarily stopped. Then, idling up can be executed by setting the transmission mechanism 5 to the neutral idle state. Hereinafter, the time chart will be described in detail.

  When the vehicle is already running in the D range and the driver depresses the brake to stop (S3), when the neutral idle execution condition is satisfied (S41), in this embodiment, the second brake 70 is Since the first brake 60 is already engaged (S42), the speed change mechanism 5 is in the interlock state. Further, the first clutch hydraulic pressure is lowered, the first clutch 40 is in the slip state from the engaged state (S43), and the transmission mechanism 5 is in the neutral idle state.

  When it is determined that the second brake 70 is engaged and the interlock is completed (S44), idle-up is performed (S45). At this time, since the first clutch 40 is slipping, the turbine 3c as the input shaft 4 of the speed change mechanism 5 is rotated at a speed substantially the same as the engine speed.

  Next, when the driver stops depressing the brake pedal and the brake pressure becomes zero (S46), the idle-up is finished (S47), the second brake 70 is released, and the first clutch 40 is engaged. (S48, 49), the speed change mechanism 5 becomes the first speed, and the vehicle starts.

  Therefore, for example, shortly after starting from a parking lot, while waiting for a signal or temporarily stopping when going out on a public road, the first clutch 40 (starting friction element) of the speed change mechanism 5 is slipped into a neutral idle state. By shifting to idle up, it is possible to satisfy both the driver's start request and early catalyst warm-up.

  In FIG. 9, the first clutch hydraulic pressure gradually increases until the first clutch 40 changes from the slip state to the engaged state at the start (see arrow c). This is to prevent the vehicle from abruptly starting by completely engaging the first clutch 40 after waiting for the reduced turbine rotation.

  Further, in FIG. 9, the period during which the neutral idle control is being performed is displayed only as “N-idle state”, but in the present embodiment, this period is actually the first brake 60 and the second brake 70. Since it is fastened, it is strictly an interlock state and a neutral idle state.

  In addition, when performing idle-up, in the case of FIG. 9, the neutral idle state (the first clutch 40 is slipped) is not brought into the interlock state (the first clutch 40 is engaged) as in the case of FIGS. The reason is as follows.

  That is, as shown in FIG. 9, when the vehicle stops after running and idles up, the hydraulic pressure is reduced from the engaged state of the first clutch 40, but even when the ATF (automatic transmission fluid) viscosity is high, The control in the direction of decreasing the hydraulic pressure is easier than the control in the direction of increasing the hydraulic pressure. In the neutral idle state, the load on the torque converter 3 is smaller than in the interlock state, and the catalyst device can be activated earlier. Therefore, in the case of FIG. 9 where the control from the engaged state to the neutral idle state is relatively easy for the first clutch 40, the catalyst device is activated in the neutral idle state where the catalyst device is easily activated.

(Modification of the first embodiment)
In the first embodiment described above, the case where the second brake 70 is engaged during the neutral idle control has been described. However, the second brake 70 may remain released. The case where the second brake 70 is left released will be described as a modification of the first embodiment with reference to FIGS. 10 and 11.

  Although there is a difference in the specific control method during neutral idle control between the modified example and the first embodiment described above, the configuration of the automatic transmission and the control device described in FIGS. 1 to 3 and The flowcharts of FIGS. 4 and 5 are common, and the other configurations that are not specifically described below have the same configuration unless there is a technical contradiction or the like.

  FIG. 10 is a flowchart showing an operation during neutral idle control. Hereinafter, the flowchart will be described along the flow.

  First, in step S41, it is determined whether or not the flag is ON. However, since the vehicle has once traveled and the flag is set in step S33, it is determined in step S41 that the flag is ON. Next, in step S42, a control signal is output to the hydraulic circuit 110 so that the transmission mechanism 5 is in the neutral idle state, that is, the hydraulic pressure supplied to the first clutch 40 is lowered to the slip state.

  As a result, if the first clutch 40 operates normally, it enters a slip state and the turbine rotation increases. However, for confirmation, in step S43, whether or not the turbine rotation has actually increased to the target value or more. When it is determined that the value is equal to or greater than the target value, idle up is performed in step S44.

  Here, if the first clutch 40 is not slipped due to some abnormality, it is determined in the step S43 that the turbine rotation is not higher than the target value, and the next step until the turbine rotation becomes higher than the target value. The idle up of S44 is not performed.

  Next, in step S45, it is determined from the signal of the brake pressure sensor 104 whether or not the brake is OFF, that is, whether or not the driver has released the brake pedal. The idle up control is continued while the mechanism 5 is in the neutral idle state.

  When the driver releases the brake pedal and determines that the brake is OFF in step S45, the hydraulic circuit 110 is controlled to end the idle-up in step S46 and to engage the first clutch 40 in step 47. Output a signal. As a result, the neutral idle state is canceled and the transmission mechanism 5 enters the first speed state and can start in response to the driver's depression of the accelerator pedal.

  Thereafter, in step S48, the neutral idle execution condition flag is canceled (OFF), and the process returns to the main routine of FIG.

  Therefore, the first embodiment (FIG. 6) is different from the first embodiment (S42) after the first clutch 40 is slipped (S42), since the second brake 70 is not engaged, the transmission mechanism 5 is interlocked in the neutral idle state. It means that it does not become a state. For this reason, idle-up is executed not when the interlock is established but when the turbine rotation reaches the target value.

  As shown in the time chart of FIG. 11, the vehicle once traveled, but also when the catalyst device is still inactive and needs to be idled up, as in the first embodiment (FIG. 9), The idle speed up can be performed by setting the speed change mechanism 5 to the neutral idle state between the temporary stop and the start again. Hereinafter, the time chart will be described in detail.

  When the vehicle is already running in the D range and the driver depresses the brake pedal to stop the vehicle (S3), the neutral idle execution condition is satisfied (S41), and the first clutch 40 is in the slip state from the engaged state. (S42), the transmission mechanism 5 is in the neutral idle state. Again, in this modified example, since the second brake 70 remains released, the speed change mechanism 5 does not enter the interlock state.

  When it is determined that the turbine rotation has reached the target value (S43), idle up is executed (S44), and the engine rotation rises to idle up rotation. At this time, since the first clutch 40 is slipping, the turbine 3c as the input shaft 4 of the speed change mechanism 5 rotates and rotates at substantially the same speed as the engine rotation (idle-up rotation).

  Next, when the driver stops the depression of the brake pedal and the brake is turned off (S45), the idle-up is finished (S46), and the first clutch hydraulic pressure gradually increases and the first clutch 40 is engaged ( S47), the speed change mechanism 5 becomes the first speed, and the vehicle starts.

  Therefore, according to the modified example, as in the first embodiment, for example, the vehicle enters the neutral idle state soon after starting from the parking lot, and while it is temporarily stopped when waiting for a signal or going on a public road. By performing the idle-up, the driver's start request and the early warming of the catalyst can both be achieved.

  Furthermore, according to the modified example, the second brake 70 remains released even during the neutral idle control. Therefore, the hydraulic control of the second brake 70 during the neutral idle control is further simplified than in the first embodiment. it can.

(About the second embodiment)
In the above-described first embodiment and its modification, the idle-up performed while the vehicle is stopped by performing the ND operation immediately after the cold start of the engine is performed while the transmission mechanism 5 is in the interlock state. As a second embodiment, the case where the transmission mechanism 5 is switched from the interlock state to the neutral idle state during idle-up will be described with reference to FIGS.

  Although the second embodiment and the first embodiment are different in the control method during idle-up, the configurations of the automatic transmission and the control device described in FIGS. 1 to 3 are common. In addition, the other configurations that are not specifically described below have the same configuration as each other unless there is a technical contradiction or the like.

  A control method for the powertrain system according to the second embodiment will be described in detail with reference to the flowcharts of FIGS.

  FIGS. 12 to 14 are flowcharts showing a specific operation of the powertrain system when performing idle-up after engine startup in the second embodiment. That is, FIG. 12 shows the main routine of idle up control, FIG. 13 shows the details of the interlock control which is a subroutine included in FIG. 12, and FIG. 14 shows the neutral idle control which is a subroutine included in FIG. It shows the details.

  First, the specific operation of the engine idle-up control including the interlock control and the like performed by the controller 100 will be described with reference to the flowchart of FIG.

  The controller 100 starts the control operation when the ignition switch of the engine is turned on while the range of the automatic transmission 1 is in the P range. First, in step S101, signals from the sensors 101 to 107 shown in FIG. 3 are input, and then in step S102, a control signal is sent to the hydraulic circuit 110 so as to engage the first brake 60 that is engaged in the P range. Output.

  Next, in step S103, it is determined from the signal from the vehicle speed sensor 102 whether the vehicle is stopped (vehicle speed is 0 km / h). When it is determined that the vehicle is stopped, it is determined in step S104 whether or not there is an idle up request for increasing the engine idle speed.

  Since it is determined that the catalyst temperature is low immediately after the engine is started and there is an idle-up request, the controller 100 next determines in step S105 whether or not the range was the D range when the stop determination was made in step S103. judge.

  Further, since the range immediately after the start of the engine is the P range, it is determined in step S105 that the stop range is not the D range, and then in step S106, it is determined whether or not the current range is the R range. . When it is determined that the current range is not the R range, that is, the P range, idle up is performed in step S107. As a result, after the engine is started, idle-up is performed in the state of the P range before the start of traveling, and activation of the catalyst device is promoted. On the other hand, if it is determined in step S106 that it is the R range, idle up is prohibited (terminated) in step S108.

  Next, in step S109, it is determined whether or not the range is the N range (including the P range) at the time of the stop determination in step S104, and the range immediately after the engine is started is the P range. It determines with YES.

  Thereafter, in step S110, it is determined whether or not an ND operation has been performed from the signal of the range sensor 101, that is, whether or not a shift operation has been performed from the N range (P range) to the D range by the driver. -Continue to idle up in the P range until it is determined that the D operation has been performed.

  Here, when an ND operation is performed during idle up execution in the P range state, it is determined in step S110 that the ND operation has been performed, and idle up is continued in the D range state. At that time, whether the brake pedal is depressed by the driver, that is, whether the brake is ON or not is determined in step S111 based on the signal of the brake pressure sensor 104, and if it is determined that the brake is ON, in step S114, Interlock control described later is executed.

  After step S114, it is determined in step S115 whether or not the first clutch 40 has reached a predetermined reduced hydraulic pressure, and the interlock control is performed until it is determined in step S115 that the predetermined reduced hydraulic pressure has been reached. When it is determined that the predetermined reduced hydraulic pressure has been reached, a neutral idle execution condition flag is set in step S116, and neutral idle control described later in step S117 is performed.

  Further, when it is determined in step S111 that the brake is not ON, it is considered that the driver has no intention to brake, and in order to start the vehicle, the first clutch 40 is engaged in step S112, and in step S113, Idle up is prohibited.

  On the other hand, when it is determined that the catalyst device is still in an inactive state and there is an idle-up request in step S104 when the vehicle is stopped after traveling, it is in the D range when the vehicle is stopped, so in step S105. In step S118, it is determined whether or not the brake is ON based on the signal from the brake pressure sensor 104. If it is determined in step S118 that the brake is ON, the process proceeds to step S117. When neutral idle control, which will be described later, is executed and it is determined in step S118 that the brake is not ON, idle up is prohibited in step S119.

  Therefore, in the main routine of the idle up control, the second embodiment is different from the first embodiment (FIG. 4) in that after the interlock control in step S114, after step S115 and step S116, step S117 is performed. There is a flow in which neutral idle control is continuously executed.

  FIG. 13 is a flowchart showing the operation during interlock control. The interlock control in step S114 will be described in detail with reference to FIG.

  First, the controller 100 engages the second brake 70 in step S121, and outputs a control signal to the hydraulic circuit 110 so that the first clutch 40 is engaged with a predetermined reduced oil pressure in step S122. As a result, the transmission mechanism 5 is in the interlock state. While the brake pedal is depressed without performing a shift operation in this interlock state, idling up is continued.

  When the brake pedal is not depressed in the D range (brake OFF), it is determined in step S123 that the brake pedal is not in the N range, it is determined in step S124 that the brake is OFF, and in step S125, the idle is increased. finish. Thereby, the idle up in D range is complete | finished.

  Next, in step S126, the first clutch 40 is engaged with the normal hydraulic pressure, and in step S127, a control signal is output to the hydraulic circuit 110 so as to release the second brake 70. After that, when the first clutch 40 is actually engaged and the second brake 70 is released, the transmission mechanism 5 is released from the interlock state, and the automatic transmission 1 is in the first speed state. Return to the routine.

  On the other hand, when the driver performs a shift operation to the N range in the interlock state, it is determined in the step S123 that the vehicle is in the N range. In step S128, the first clutch 40 is released, and in step S129. Then, a control signal is output to the hydraulic circuit 110 so as to release the second brake 70. As a result, the hydraulic pressure is simultaneously discharged from both friction elements by the hydraulic circuit 110, the transmission mechanism 5 is released from the interlock state, the automatic transmission 1 enters the N range state, and continues to idle up. Thereafter, the process returns to the main routine of FIG.

  Therefore, in the interlock control, the second embodiment is different from the first embodiment (FIG. 5) in that the neutral idle is executed after it is determined in step 124 that the brake is OFF and the vehicle starts to start. The condition flag is not set.

  FIG. 14 is a flowchart showing the operation during neutral idle control. The flowchart of FIG. 14 has the same content as the flowchart of FIG. 6 showing the operation during the neutral idle control of the first embodiment (only the step number is different), and this content has already been described in detail. Therefore, the description is omitted here.

  Next, regarding a vehicle to which the powertrain system according to the second embodiment is applied, various states of the vehicle (engine, automatic transmission, etc.) when the driver performs ND operation immediately after the cold start of the engine. Will be described in detail according to the time chart of FIG.

  As shown in the time chart of FIG. 15, even when the vehicle is stopped for a while after the ND operation immediately after the cold start of the engine, the interlock is kept while stopping until starting in the D range. By switching from the state to the neutral idle state, it is possible to idle up. Hereinafter, the time chart will be described in detail.

  In the initial N range, the vehicle is stopped when the brake is ON, the engine is rotating at idle-up rotation, and only the first brake 60 of the transmission mechanism 5 is engaged. At this time, since the first clutch 40 is disengaged, the turbine 3c as the input shaft 4 of the speed change mechanism 5 rotates and rotates at substantially the same speed as the engine rotation (idle-up rotation).

  Here, since the idle-up request is ON, when the driver performs an ND operation (S110), interlock control is performed (S114).

  By performing the interlock control, the second brake 70 is engaged and the first clutch 40 is engaged with a predetermined reduced hydraulic pressure (S121, S122), and the transmission mechanism 5 enters the interlock state. At this time, the rotation of the turbine 3c decelerates as the first clutch hydraulic pressure increases until the first clutch 40 is engaged.

  Next, when the first clutch 40 reaches a predetermined reduced hydraulic pressure (S115), a neutral idle execution condition flag is set (S116), and neutral idle control is executed (S117). At this time, since the hydraulic pressure of the first clutch 40 is reduced and the slip state is established (S143), the rotation of the turbine 3c increases again.

  In the drawing, the period during which the neutral idle control is being performed is displayed only as “N-idle state”, but in the present embodiment as well, the first brake 60 and the second brake 70 are actually in this period. Strictly speaking, the transmission mechanism 5 is in the interlock state and in the neutral idle state because it is fastened.

  Next, when the driver removes his / her foot from the brake pedal (S146), the idle-up is finished (S147), the second brake 70 is released, the first clutch 40 is engaged (S148, S149), and the speed change is performed. The mechanism 5 becomes the first speed, and the vehicle starts.

  Therefore, according to the second embodiment, in the same way as in the first embodiment, for example, in order to promote the activation of the catalytic device even in the slight stoppage time in the D range when starting from the garage, The idling-up control can be performed satisfactorily without deteriorating the start response and unintentional start.

  Further, according to the second embodiment, the torque converter is operated from the interlocked state (the first brake 60 and the second brake 70 are engaged) and the first clutch 40 is engaged during the idle-up in the D range. Therefore, the catalyst device can be activated more quickly than in the first embodiment.

(About the third embodiment)
Next, a case where a continuously variable transmission is used as an automatic transmission in a vehicle powertrain system will be described as a third embodiment with reference to FIGS. 16 to 24.

  A vehicle powertrain system to which a third embodiment of the present invention is applied will be described. This powertrain system 201 is for a front engine / front drive vehicle, and is a horizontally installed engine 202, a belt type continuously variable transmission (hereinafter referred to as "automatic transmission") 203 as an automatic transmission, And a controller 300 for controlling the engine 202 and the automatic transmission 203. On the exhaust path of the engine 202, a catalyst device (not shown) for removing harmful components in the exhaust gas is disposed. Yes.

  FIG. 16 is a skeleton diagram showing a configuration of an automatic transmission (continuously variable transmission) constituting the powertrain system. As shown in FIG. 16, the automatic transmission 203 includes a torque converter 210 connected to the output shaft 202a of the engine 202, a forward / reverse switching mechanism 220 disposed on the opposite side of the torque converter 210, and the switching mechanism. 220 and a continuously variable transmission mechanism 230 disposed on the side opposite to the engine. A final reduction gear 240 and a differential device 250 are provided on the output side of the automatic transmission 203. 251 and 252 are transmitted.

  The torque converter 210 in the automatic transmission 203 includes a case 211 connected to the engine output shaft 202a, a pump 212 fixed in the case 211 and integrally rotated with the engine output shaft 202a, and the pump 212. A turbine 213 driven via hydraulic oil in the case 211, a stator 214 interposed between the turbine 213 and the pump 212 for increasing torque, and the case 211 and the turbine 213 are combined. And a lock-up clutch 215 that directly connects the turbine 213 to the engine output shaft 202a, and a turbine shaft 216 connected to the turbine 213 extends to the switching mechanism 220 side as an input shaft of the forward / reverse switching mechanism 220.

  An oil pump 217 that is driven by the engine output shaft 202a through the case 211 of the torque converter 210 is provided on the opposite side of the torque converter 210 from the engine.

  The forward / reverse switching mechanism 220 includes a carrier 222 connected to the turbine shaft 216, first and second pinions 223a and 223b supported by the carrier 222 and meshed with each other, and a sun gear 224 meshed with the first pinion 223a, And a double pinion planetary gear mechanism 221 comprising a ring gear 225 meshed with the second pinion 223b, a forward clutch 226 connecting and disconnecting the carrier 222 of the planetary gear mechanism 221 and the ring gear 225, and a ring gear of the planetary gear mechanism 221. And a reverse brake 227 for fixing 225, and an input shaft 228 is connected to the sun gear 224 of the planetary gear mechanism 221.

  When the forward clutch 226 is engaged and the reverse brake 227 is released, the entire planetary gear mechanism 221 is integrated, and the rotation of the turbine shaft 216 is directly output to the input shaft 228 via the planetary gear mechanism 221. When the forward clutch 226 is released and the reverse brake 227 is engaged, the rotation of the turbine shaft 216 is decelerated and reversed by the planetary gear mechanism 221 and output to the input shaft 228.

  Further, the continuously variable transmission mechanism 230 includes a primary pulley 231 disposed on an input shaft (an output shaft of the forward / reverse switching mechanism 220) 228 and a secondary pulley disposed on an output shaft 232 parallel to the input shaft 228. 233 and a V belt 234 wound between the pulleys 231 and 233. The primary pulley 231 and the secondary pulley 233 are respectively a fixed disk 231a fixed to the input shaft 228 and the output shaft 232, 233a and movable disks 231b and 233b that are slidably supported on the input shaft 228 and the output shaft 232, respectively, facing the disks 231a and 233a.

  Cylinders 231c and 233c are provided behind the movable disks 231b and 233b, and the holding position of the V-belt 234 in both pulleys 231 and 233 is changed by the supply / discharge control of the operating pressure to these cylinders 231c and 233c. As a result, the gear ratio between the input and output shafts 228 and 232, that is, the gear ratio as the automatic transmission 203 is controlled.

  FIG. 17 is a table showing the relationship between the engagement combinations of the friction elements of the automatic transmission 203 and the ranges (blank portions indicate that the friction elements are released).

  As will be described later, the automatic transmission 203 is provided with a hydraulic circuit 310 that controls the engagement state of the forward clutch 226 and the reverse brake 227 in accordance with the operation of the driver. As shown in the table, the forward travel D range (hereinafter referred to as “D range”) in which the forward clutch 226 is engaged and the reverse brake 227 is released, and the forward clutch 226 is released and the reverse brake 227 is engaged. The reverse range for reverse travel (hereinafter referred to as “R range”) is realized. Further, although not described in the table, a neutral N range and a P range (hereinafter referred to as “N range” representatively) in which the forward clutch 226 and the reverse brake 227 are released are also realized. It has become.

  On the other hand, FIG. 17 also shows a combination of the engagement of the friction elements during the interlock control and the neutral idle control of the automatic transmission 203 according to the present embodiment.

  First, in the present embodiment, when the engine stops in the D range immediately after the cold start of the engine, that is, the ND operation is performed while the brake pedal is depressed, and the vehicle stops in the D range, the table in FIG. As shown, interlock control is performed to place the automatic transmission 203 in the interlock state by simultaneously engaging the reverse clutch 226 engaged in the R range together with the forward clutch 226 engaged in the D range.

  Further, in the present embodiment, when the catalyst device is still in an inactive state after running once and stops in the D range, that is, with the D range selected, the foot is released from the accelerator pedal and the brake pedal is depressed. As shown in the table of FIG. 17, neutral idle control is performed in which the engagement force of the forward clutch 226 engaged in the D range is reduced to bring it into a slip state with the reverse brake 227 released as shown in the table of FIG. 17.

  Then, by the interlock control and the neutral idle control as described above, the automatic transmission 203 executes the idle up while the desired engagement state is established, thereby promoting the activation of the catalyst device.

  Next, a control device for controlling the powertrain system according to the third embodiment will be described in detail with reference to FIG.

  FIG. 18 is a block diagram illustrating a configuration of a control device according to the third embodiment. As shown in FIG. 18, the automatic transmission 203 selectively supplies line pressure to the forward clutch 226, the reverse brake 227, and the cylinders 231c and 233c of the continuously variable transmission mechanism 230 to realize a desired gear ratio. A hydraulic circuit 310 is provided, and the circuit 310 is provided with a solenoid valve 310a for speed change control.

  Furthermore, a controller 300 is provided to control these solenoid valves 310a. The controller 300 detects a signal from a range sensor 301 that detects a range selected by a driver's operation, a signal from a vehicle speed sensor 302 that detects the vehicle speed of the vehicle, and a driver's accelerator pedal operation amount. A signal from the accelerator sensor 303 that performs the operation, a signal from the brake pressure sensor 304 that detects the amount of brake pedal operation by the driver, a signal from the engine speed sensor 305 that detects the rotational speed of the engine output shaft 2, and the turbine 213 A signal from the turbine rotational speed sensor 306 for detecting the rotational speed of the engine, a signal from the hydraulic sensor 307 for sensing the engagement state of the friction element, and the like are input, and a control signal is output to each solenoid valve 310a of the hydraulic circuit 310. Is done.

  As a result, the opening / closing or opening of each solenoid valve 310a is controlled according to the selected range and the driving state of the vehicle, and is selectively applied to the forward clutch 226, the reverse brake 227, and the cylinders 231c and 233c of the continuously variable transmission mechanism 230. The line pressure is supplied to the D range, the R range, the interlock, and the neutral idle state of a desired gear ratio according to the table of FIG.

  Next, the control method of the powertrain system according to the third embodiment will be described in detail according to the flowcharts of FIGS.

  FIG. 19 to FIG. 21 are flowcharts showing specific operations of the powertrain system when performing idle-up in the third embodiment. That is, FIG. 19 shows the main routine of idle up control, FIG. 20 shows the details of the interlock control which is a subroutine included in FIG. 19, and FIG. 21 shows the neutral idle control which is a subroutine included in FIG. It shows the details.

  First, the idle-up control by the controller 300 will be described with reference to the flowchart of FIG.

  The controller 300 starts the control operation when the ignition switch of the engine is turned on while the range of the automatic transmission 203 is the P range. First, in step S201, signals from the sensors 301 to 307 shown in FIG. 18 are input.

  Next, in step S202, it is determined from the signal from the vehicle speed sensor 302 whether the vehicle is stopped (vehicle speed is 0 km / h). When it is determined that the vehicle is stopped, it is determined in step S203 whether or not there is an idle up request for increasing the engine idle speed.

  Since it is determined that the catalyst temperature is low immediately after the engine is started and there is an idle-up request, the controller 300 next determines in step S204 whether or not the range was the D range at the time of stop determination in step S202. judge.

  Further, since the range immediately after the start of the engine is the P range, it is determined in step S204 that the stop range is not the D range, and then in step S205, it is determined whether the current range is the R range. . When it is determined that the current range is not the R range, that is, the P range, idle up is performed in step S206. As a result, after the engine is started, idle-up is performed in the state of the P range before the start of traveling, and activation of the catalyst device is promoted. On the other hand, if it is determined in step S205 that it is in the R range, idle up is prohibited (terminated) in step S207.

  Next, in step S208, it is determined whether or not the range is the N range (including the P range) at the time of the stop determination in step S202, and the range immediately after the engine is started is the P range. It determines with YES.

  Thereafter, in step S209, it is determined whether or not an ND operation has been performed from the signal of the range sensor 301, that is, whether or not a shift operation has been performed from the N range (P range) to the D range by the driver. -Continue to idle up in the P range until it is determined that the D operation has been performed.

  Here, when the ND operation is performed while performing the idle up in the P range state, it is determined in step S209 that the ND operation has been performed, and the idle up is continued in the D range state. . At that time, it is determined in step S210 based on the signal from the brake pressure sensor 304 whether or not the brake pedal is depressed by the driver, that is, whether the brake is ON. If it is determined that the brake is ON, in step S213, Interlock control described later is executed. On the other hand, when it is determined in step S210 that the brake is not ON, it is considered that the driver has no intention to brake, and the vehicle is started. Therefore, in step S211, the forward clutch 226 is engaged, and in step S212, Idle up is prohibited.

  On the other hand, when it is determined that the catalyst device is still in an inactive state and there is an idle-up request in step S203 when the vehicle is stopped after traveling, it is in the D range when the vehicle is stopped, so in step S204. In step S214, it is determined whether or not the brake is ON based on the signal from the brake pressure sensor 304. If it is determined in step S214 that the brake is ON, the process proceeds to step S215. When neutral idle control, which will be described later, is executed and it is determined in step S214 that the brake is not ON, idle up is prohibited in step S216.

  FIG. 20 is a flowchart showing the operation during interlock control. The interlock control in step S213 will be described in detail with reference to FIG.

  First, the controller 300 outputs a control signal to the hydraulic circuit 310 so as to engage the reverse brake 227 in step S221. As a result, the automatic transmission 203 enters an interlock state. While the brake pedal is depressed without performing a shift operation in this interlock state, idling up is continued.

  If the brake pedal is not depressed in the D range (brake OFF), it is determined in step S223 that the brake pedal is not in the N range, it is determined in step S224 that the brake is OFF, and in step S225, idle up is performed. finish. Thereby, the idle up in D range is complete | finished.

  Next, in step S226, the forward clutch 226 is engaged with the normal hydraulic pressure, and in step S227, a control signal is output to the hydraulic circuit 310 so as to release the reverse brake 227. Thereafter, when the forward clutch 226 is actually engaged and the reverse brake 227 is released, the automatic transmission 203 is released from the interlock state, and the automatic transmission 203 enters the first speed state.

  Next, in step S228, based on the signal from the vehicle speed sensor 302, it is determined whether or not the vehicle has reached a predetermined vehicle speed (for example, 3 km / h) or more. Then, the neutral idle execution condition flag is set (ON), and the process returns to the main routine of FIG.

  On the other hand, when the driver performs a shift operation to the N range in the interlock state, it is determined in the step S223 that the vehicle is in the N range. In step S230, the forward clutch 226 is released, and in step S231, A control signal is output to the hydraulic circuit 310 so as to release the reverse brake 227. As a result, hydraulic pressure is simultaneously discharged from both friction elements by the hydraulic circuit 310, the automatic transmission 203 is released from the interlock state, and the automatic transmission 203 enters the N range state, but continues to idle up. Thereafter, the process returns to the main routine of FIG.

  According to the above interlock control, the forward clutch 226 that is the starting friction element is engaged with the hydraulic pressure already increased to a reduced hydraulic pressure while the vehicle is stopped in the D range, so that when the driver brakes off In addition, the hydraulic pressure of the starting friction element can be quickly increased to the normal hydraulic pressure, and the start response is not deteriorated. In addition, the automatic transmission 203 is in an interlock state during idle-up and the creep force is suppressed, so that the creep force increases and overcomes the braking force caused by the depression of the brake pedal of the driver before the start of driving. There is no risk that the vehicle will start unintentionally.

  FIG. 21 is a flowchart showing the operation during neutral idle control. The neutral idle control in step S205 will be described in detail with reference to FIG.

  First, in step S241, it is determined whether or not the flag is ON. However, since the vehicle has once traveled and the flag is set in step S229, it is determined in step S241 that the flag is ON. Next, in step S242, a control signal is output to the hydraulic circuit 310 so that the automatic transmission 203 is in the neutral idle state, that is, the hydraulic pressure supplied to the forward clutch 226 is reduced to the slip state.

  As a result, if the forward clutch 226 operates normally, the forward clutch 226 enters a slip state and the turbine rotation increases. However, for confirmation, in step S243, whether or not the turbine rotation actually increased and exceeded the target value. When it is determined that the value is equal to or greater than the target value, idle up is performed in step S244.

  Here, if the forward clutch 226 does not enter the slip state due to some abnormality, it is determined in step S243 that the turbine rotation is not higher than the target value, and the next step S244 is continued until the turbine rotation exceeds the target value. Do not idle up.

  Next, in step S245, it is determined from the signal from the brake pressure sensor 304 whether or not the brake is OFF, that is, whether or not the driver has released the brake pedal. The idle up control is continued while the transmission 203 is in the neutral idle state.

  When the driver releases the brake pedal and determines that the brake is OFF in step S245, the idle-up is terminated in step S246, the reverse brake 227 is released in step S247, and the forward clutch is determined in step S248. A control signal is output to the hydraulic circuit 310 so that the H.226 is engaged. As a result, the automatic transmission 203 is released from the neutral idle state and is in the first speed state, and can start when the driver depresses the accelerator pedal.

  Thereafter, in step S249, the neutral idle execution condition flag is canceled (OFF), and the process returns to the main routine of FIG.

  According to the above neutral idle control, the forward clutch 226 that is the starting friction element is slipped with the hydraulic pressure raised to some extent without being completely released while the vehicle is stopped in the D range. When the driver loosens the brake pedal, the hydraulic pressure of the starting friction element can be quickly increased to the normal hydraulic pressure, and both the driver's start request and early catalyst warm-up can be achieved.

  Next, FIG. 22 shows changes in various states of the vehicle (the states of the engine, the automatic transmission, etc.) when the vehicle to which the powertrain system according to the third embodiment is applied is driven by various methods. This will be described in detail according to the time chart of FIG.

  22 to 24 are time charts showing changes in various states of the vehicle during different driving operations. That is, FIG. 22 shows the N range → D range (interlock state) → N range operation, FIG. 23 shows the N range → D range (interlock state) → start operation, and FIG. (Neutral idle state) → Time charts at the time of starting operation are shown.

  As shown in the time chart of FIG. 22, the automatic transmission 203 is operated while the vehicle is stopped in the D range even after the ND operation immediately after the cold start of the engine and when the operation is returned to the N range. Idle up can be performed in the interlock state. Hereinafter, the time chart will be described in detail.

  In the initial N range, the brake is on and the vehicle is stopped, and the idle up request is on, so the engine is rotating at idle up rotation, and the forward clutch 226 and the reverse brake 227 of the automatic transmission 203 are released. It is the state that was done. At this time, since the forward clutch 226 is released, the turbine 213 as the input shaft of the forward / reverse switching mechanism 220 of the automatic transmission 203 rotates and rotates at substantially the same speed as the engine rotation.

  Here, since the idle up request is ON, when an ND operation is performed (S209), interlock control is performed (S213).

  By performing this interlock control, the reverse brake 227 is engaged and the forward clutch 226 is engaged with a predetermined reduced hydraulic pressure (S221, S222), and the automatic transmission 203 enters the interlock state. At this time, as the hydraulic pressure increases until the forward clutch 226 is engaged, the rotation of the turbine 213 is decelerated.

  Next, when the driver performs an operation of returning from the D range to the N range (S223), the forward clutch 226 and the reverse brake 227 are released (S230 and S231), and the interlock is released. At this time, since the forward clutch 226 is released, the turbine rotation rises again.

  Therefore, for example, when the vehicle is temporarily shifted to the D range to start from the garage, but for some reason the start is stopped and returned to the N range, the automatic transmission 203 is stopped while the vehicle is stopped in the D range. By performing idle-up in the interlock state, it is possible to perform idle-up control in the D range satisfactorily without causing an unintended start or the like in order to promote activation of the catalyst device.

  As shown in the time chart of FIG. 23, even when the vehicle is stopped for a while after the ND operation immediately after the cold start of the engine, the interlock is kept while the vehicle is stopped until starting in the D range. Idle up can be performed in the state. Hereinafter, the time chart will be described in detail.

  The state from the initial stop in the N range to the interlock state in the D range is the same as in the case of FIG.

  Next, when the driver removes his foot from the brake pedal in the interlock state (S224), the idle-up is finished (S225), and the hydraulic pressure supplied to the forward clutch 226 increases from the reduced hydraulic pressure to the normal hydraulic pressure. At the same time, the reverse brake 227 is released (S226, S227), the interlock is released, the automatic transmission 203 enters the D range, and the vehicle can start.

  In FIG. 23, when the automatic transmission 203 changes from the interlock state to the D range, the hydraulic pressure of the reverse brake 227 gradually decreases (see arrow a). This is to prevent the vehicle from starting suddenly by completely releasing the reverse brake 227 after waiting for the engine rotation to reach a predetermined rotation (see arrow b).

  When the vehicle speed exceeds the predetermined vehicle speed (S228), a neutral idle execution condition flag is set (S229).

  Therefore, for example, even in a short stop time in the D range when starting from the garage, the automatic transmission 203 is in an interlocked state and idle-up is performed to promote activation of the catalyst device in the D range. The idle-up control can be performed satisfactorily without causing deterioration in start response or unintended start.

  As shown in the time chart of FIG. 24, the vehicle once traveled, but when the catalyst device is still in an inactive state and needs to be idled up, the time between the temporary stop in the D range and the start again. The idle transmission can be executed by setting the automatic transmission 203 to the neutral idle state. Hereinafter, the time chart will be described in detail.

  When the vehicle is already running in the D range and the driver depresses the brake to stop (S204), when the neutral idle execution condition is satisfied (S241), the forward clutch hydraulic pressure is reduced and the forward clutch 226 is reduced. Is in the slip state from the engagement (S242), and the automatic transmission 203 is in the neutral idle state.

  When it is determined that the turbine rotation has reached the target value (S243), idle-up is executed (S244). At this time, because the forward clutch 226 is slipping, the turbine 213 as the input shaft of the forward / reverse switching mechanism 220 of the automatic transmission 203 rotates and rotates at substantially the same speed as the engine rotation.

  Next, when the driver stops the depression of the brake and the brake pressure becomes zero, the idle-up is finished (S246), the reverse brake 227 is released, and the forward clutch 226 is engaged (S247, S248). The automatic transmission 203 is in the D range, and the vehicle can start.

  Therefore, for example, shortly after starting from a parking lot, while waiting for a traffic light or temporarily stopping when going out on a public road, the forward clutch 226 (starting friction element) is shifted to the neutral idle state to slip and idle up. By performing the above, it is possible to satisfy both the driver's start request and the early warming of the catalyst.

  In FIG. 24, the forward clutch hydraulic pressure gradually increases until the forward clutch 226 changes from the slip state to the engaged state at the time of starting (see arrow c). However, this is a high rotation speed in the neutral idle state. This is to prevent the vehicle from starting suddenly by completely engaging the forward clutch 226 after waiting for the turbine rotation to decelerate.

  In addition, when performing idle up, in the case of FIG. 24, the neutral idle state (the forward clutch 226 is slipped) is not set to the interlock state (the forward clutch 226 is engaged) as in FIGS. For the following reasons.

  That is, as shown in FIG. 24, when the vehicle is stopped after running and idle-up is performed, the hydraulic pressure is lowered from the engaged state of the forward clutch 226. However, even when the ATF viscosity is low and the temperature is low, Control is easier than control in the direction of increasing the hydraulic pressure. In the neutral idle state, the load on the torque converter 210 is smaller than in the interlock state, and the catalyst device can be activated earlier. Therefore, in the case of FIG. 24 in which the forward clutch 226 is relatively easily controlled from the engaged state to the neutral idle state, the catalyst device is activated in the neutral idle state where the catalyst device is easily activated.

(About the fourth embodiment)
In the above-described third embodiment, the idle-up performed while the vehicle is stopped by performing the ND operation immediately after the cold start of the engine is performed while the automatic transmission 203 is in the interlock state. As an embodiment, a case where the automatic transmission 203 is switched from the interlock state to the neutral idle state during idle-up will be described with reference to FIGS. 25 to 28.

  Although the fourth embodiment and the third embodiment are different in the control method during the idle-up control, the configurations of the automatic transmission and the control device described in FIGS. 16 to 18 are common. In addition, the other configurations that are not particularly described below have the same configuration as each other unless there is a technical contradiction or the like.

  Next, a control method of the powertrain system according to the fourth embodiment will be described in detail according to the flowcharts of FIGS.

  FIGS. 25 to 27 are flowcharts showing a specific operation of the powertrain system when performing idle-up after engine startup in the fourth embodiment. 25 shows the main routine of the idle up control, FIG. 26 shows the details of the interlock control which is a subroutine included in FIG. 25, and FIG. 27 shows the neutral idle control which is a subroutine included in FIG. It shows the details.

  The controller 300 starts the control operation when the ignition switch of the engine is turned on while the range of the automatic transmission 203 is the P range. First, in step S301, signals from the sensors 301 to 307 shown in FIG. 18 are input.

  Next, in step S302, it is determined from the signal of the vehicle speed sensor 302 whether the vehicle is stopped (vehicle speed is 0 km / h). When it is determined that the vehicle is stopped, it is determined in step S303 whether or not there is an idle up request for increasing the engine idle speed.

  Since it is determined that the catalyst temperature is low immediately after the engine is started and there is an idle-up request, the controller 300 next determines in step S304 whether or not the range was the D range at the stop determination in step S302. judge.

  In addition, since the range immediately after the engine is started is the P range, it is determined in step S304 that the stop range is not the D range, and then in step S305, it is determined whether the current range is the R range. . When it is determined that the current range is not the R range, that is, the P range, idle up is performed in step S306. As a result, after the engine is started, idle-up is performed in the state of the P range before the start of traveling, and activation of the catalyst device is promoted. On the other hand, if it is determined in step S305 that it is the R range, idle up is prohibited (terminated) in step S307.

  Next, in step S308, it is determined whether or not the range is the N range (including the P range) at the time of the stop determination in step S302, and the range immediately after the engine is started is the P range. It determines with YES.

  Thereafter, in step S309, it is determined whether or not an ND operation has been performed from the signal of the range sensor 301, that is, whether or not the driver has performed a shift operation from the N range (P range) to the D range. -Continue to idle up in the P range until it is determined that the D operation has been performed.

  Here, when the ND operation is performed while performing the idle up in the P range state, it is determined in step S309 that the ND operation has been performed, and the idle up is continued in the D range state. . At that time, whether or not the brake pedal is depressed by the driver, that is, whether or not the brake is ON is determined in step S310 based on the signal of the brake pressure sensor 304, and when it is determined that the brake is ON, in step S313, Interlock control described later is executed.

  After step S313, it is determined in step S314 whether or not the forward clutch 226 has reached a predetermined reduced hydraulic pressure, and the interlock control is continued until it is determined in step S314 that the predetermined reduced hydraulic pressure has been reached. When it is determined that the predetermined reduced hydraulic pressure has been reached, a neutral idle execution condition flag is set in step S315, and neutral idle control described later in step S316 is performed.

  If it is determined in step S310 that the brake is not ON, it is considered that the driver has no intention to brake and the vehicle is started. Therefore, in step S311, the forward clutch 226 is engaged, and in step S312, the idle state is set. Prohibit up.

  On the other hand, when it is determined that the catalyst device is still in an inactive state and there is an idle up request in step S303 when the vehicle is stopped after traveling, it is in the D range when the vehicle is stopped, so in step S304. When it is determined that the vehicle is in the D range at the time of stoppage determination, it is determined in step S317 whether or not the brake is ON based on a signal from the brake pressure sensor 304. If it is determined in step S317 that the brake is ON, When neutral idle control, which will be described later, is executed and it is determined in step S317 that the brake is not ON, idle up is prohibited in step S318.

  Therefore, in the main routine for idle-up control, the fourth embodiment differs from the third embodiment (FIG. 19) in that after step S313 interlock control, step S314 and step S315 are performed, and then step S316 is performed. There is a flow for carrying out the neutral idle control continuously.

  FIG. 26 is a flowchart showing an operation during interlock control. The interlock control in step S310 will be described in detail with reference to FIG.

  First, in step S321, the controller 300 outputs a control signal to the hydraulic circuit 310 so as to engage the reverse brake 227. As a result, the automatic transmission 203 enters an interlock state. While the brake pedal is depressed without performing a shift operation in this interlock state, idling up is continued.

  If the brake pedal is not depressed in the D range (brake OFF), it is determined in step S323 that the brake pedal is not in the N range. In step S324, it is determined that the brake is OFF. In step S325, the idle is increased. finish. Thereby, the idle up in D range is complete | finished.

  Next, in step S326, the forward clutch 226 is engaged with the normal hydraulic pressure, and in step S327, a control signal is output to the hydraulic circuit 310 so as to release the reverse brake 227. Thereafter, when the forward clutch 226 is actually engaged and the reverse brake 227 is released, the automatic transmission 203 is released from the interlock state, and the automatic transmission 203 enters the first speed state. Thereafter, the process returns to the main routine of FIG.

  On the other hand, when the driver performs a shift operation to the N range in the interlock state, it is determined in the step S323 that the vehicle is in the N range. In step S328, the forward clutch 226 is released, and in step S329, A control signal is output to the hydraulic circuit 310 so as to release the reverse brake 227. As a result, hydraulic pressure is simultaneously discharged from both friction elements by the hydraulic circuit 310, the automatic transmission 203 is released from the interlock state, and the automatic transmission 203 enters the N range state, but continues to idle up. Thereafter, the process returns to the main routine of FIG.

  Therefore, in the interlock control, the fourth embodiment is different from the third embodiment (FIG. 20) in that neutral idle is performed after it is determined that the brake is OFF in step S324 and the vehicle starts to start. The condition flag is not set.

  FIG. 27 is a flowchart showing an operation during neutral idle control. The flowchart of FIG. 27 has the same content as the flowchart of FIG. 21 showing the operation at the neutral idle control of the third embodiment (only the step number is different), and this content has already been described in detail. Therefore, the description is omitted here.

  Next, regarding the vehicle to which the powertrain system according to the fourth embodiment is applied, various states of the vehicle (engine, automatic transmission, etc.) when the driver performs ND operation immediately after the cold start of the engine. Will be described in detail according to the time chart of FIG.

  As shown in the time chart of FIG. 28, even when the vehicle is stopped for a while after the ND operation immediately after the cold start of the engine, the interlock is kept while the vehicle is stopped until starting in the D range. By performing control and neutral idle control, it is possible to perform idle up. Hereinafter, the time chart will be described in detail.

  In the initial N range, the vehicle is stopped when the brake is ON, the engine is rotating at idle-up rotation, and the forward clutch 226 and the reverse brake 227 are released. At this time, since the forward clutch 226 is released, the turbine 213 as the input shaft of the forward / reverse switching mechanism 220 of the automatic transmission 203 rotates and rotates at substantially the same speed as the engine rotation.

  Here, since the idle-up request is ON, when the driver performs an ND operation (S309), interlock control is performed (S313).

  By performing this interlock control, the reverse brake 227 is engaged and the forward clutch 226 is engaged with a predetermined reduced hydraulic pressure (S321, S322), and the automatic transmission 203 enters the interlock state. At this time, the rotation of the turbine 213 decelerates as the hydraulic pressure increases until the forward clutch 226 is engaged.

  Next, when the forward clutch 226 reaches a predetermined reduced hydraulic pressure (S314), a neutral idle execution condition flag is set (S315), and neutral idle control is executed (S316). At this time, the forward clutch 226 is in a slip state with the hydraulic pressure reduced, so that the rotation of the turbine 213 increases again.

  Next, when the driver removes his / her foot from the brake pedal, the idle up is finished (S346), the reverse brake 227 is released, the forward clutch 226 is engaged (S347, S348), and the automatic transmission 203 is set to D. It becomes a range and the vehicle can start.

  Therefore, according to the fourth embodiment, as in the third embodiment, for example, the D range is used to promote the activation of the catalyst device even during a short stoppage time in the D range when starting from the garage. The idling-up control can be performed satisfactorily without deteriorating the start response and unintentional start.

  Furthermore, according to the fourth embodiment, the neutral idle state in which the load on the torque converter 210 is less from the interlock state (the forward clutch 226 and the reverse brake 227 are engaged) during idle up in the D range. Since the forward clutch 226 is switched to slip, the catalyst device can be activated earlier than in the third embodiment.

  Note that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the scope of the present invention.

  As described above, according to the present invention, a control method and a powertrain for a vehicle powertrain system in which a fluid transmission device is disposed between an engine and a transmission mechanism, and a catalyst device is disposed in an exhaust passage of the engine. In the system, at the time of cold start, in order to promote the activation of the catalytic device, the idle up control in the D range can be performed satisfactorily without causing deterioration of start response or unintentional start. It may be suitably used in the field of manufacturing vehicles of various types of vehicles.

1 Automatic transmission 3 Torque converter (fluid transmission)
5 Transmission mechanism 40 First clutch (starting friction element)
60 1st brake 70 2nd brake 100 Controller (control device)
203 Automatic transmission 210 Torque converter (fluid transmission)
226 Forward clutch (starting friction element)
227 Reverse brake 300 Controller (control device)

Claims (3)

Engine,
A catalyst device disposed on an exhaust path of the engine;
An automatic transmission having a transmission mechanism and a fluid transmission device provided on a power transmission path from the engine to the transmission mechanism;
A control device for controlling the engine and the automatic transmission;
A powertrain system control method comprising:
When the catalyst device is in an inactive state during idle operation of the engine, the step of increasing the idle speed of the engine compared to when in the active state;
During the execution of the step, when the automatic transmission is switched from the non-traveling range to the traveling range in a state in which there is a braking request from the driver, the starting friction element in the transmission mechanism of the automatic transmission is fastened. And realizing an interlock state of the transmission mechanism by fastening a predetermined friction element;
After realizing the interlock state in the step, when there is a request for activating the catalyst device and a braking request by the driver, the automatic transmission is moved by moving the starting friction element to the release side. Realizing the neutral idle state of
A control method for a powertrain system, comprising: Furthermore,
During achieve an interlock state of the automatic transmission, when the there is the driver of the start request, the steps of starting the vehicles to release the interlocking condition,
When there is a braking request from the driver in the stop state of the vehicle after the step, control for realizing a neutral idle state of the automatic transmission is performed by shifting the starting friction element to the release side. Steps to do,
The method for controlling a powertrain system according to claim 1, comprising: Engine,
A catalyst device disposed on an exhaust path of the engine;
An automatic transmission having a transmission mechanism and a fluid transmission device provided on a power transmission path from the engine to the transmission mechanism;
A control device for controlling the engine and the automatic transmission;
A powertrain system with
The controller is
During idle operation of the engine, when the catalyst device is in an inactive state, the idling speed of the engine is increased compared to when in the active state,
When the automatic transmission is switched from the non-traveling range to the traveling range while the engine is idling at a high speed and there is a braking request from the driver, the automatic transmission starts in the transmission mechanism. When fastening the friction element, the interlocking state of the transmission mechanism is realized by fastening a predetermined friction element,
After realizing the interlock state, when there is a request to activate the catalyst device and a braking request by the driver, the starting frictional element is shifted to the release side, thereby neutralizing the automatic transmission. A powertrain system characterized by realizing an idle state.