JP2014062581A - Control method for power train system, and power train system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power train system for a vehicle including an engine and an automatic transmission, capable of continuously executing idle-up even after changeover from a non-travel range to a travel range and preventing shock during reset into the non-travel range again, in a case that a catalyst device is arranged on an exhaust passage of the engine.SOLUTION: When a catalyst device is in an inactive condition during idling operation, idle-up is performed with an idling speed being higher than in an active condition. When a vehicle braking demand is given by a driver during the idle-up and a travel range is set, predetermined friction elements except starting friction elements of a transmission mechanism are fastened to bring the transmission mechanism into an interlock condition. When a range of the automatic transmission is changed into a non-travel range in the interlock condition, the starting friction elements are released earlier than the predetermined friction elements.

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.

  In vehicles such as automobiles, a catalyst device is installed in the exhaust path of the engine in order to remove harmful components in the exhaust gas. However, this catalyst device does not function effectively in a low temperature state, and during cold start of the engine It is necessary to quickly increase the temperature to activate it. In view of this, a technology has been put to practical use that performs idle-up control for increasing the idle speed at the time of cold start of the engine, exhausts hot exhaust gas to the exhaust path, and rapidly raises the temperature of the catalyst device.

  In this case, if this idle-up control is performed in a travel range such as the D range in a vehicle equipped with an automatic transmission having a fluid transmission device such as a torque converter, the creep force increases due to the high idle speed. Therefore, the vehicle may start unexpectedly by overcoming the braking request by the driver's depression of the brake pedal before the start of traveling. Therefore, conventionally, the catalyst device is activated early by idling up at the cold start. The control is performed only in the non-traveling range such as the P range and the N range, and is terminated when the driver operates the traveling range.

  On the other hand, in order to respond to the recent tightening of exhaust gas regulations, it is required to further shorten the activation time of the catalyst device, and therefore, when the transition from the non-traveling range to the traveling range, by suppressing the creep force, It is considered that the idle-up control is continuously performed after the shift to the traveling range without being interrupted.

  As a method of suppressing the creep force in the travel range, Patent Document 1 discloses a method of limiting transmission of engine output to driving wheels by slipping a predetermined friction element fastened in the travel range (so-called neutral). Idle control) is disclosed.

  In this method, when switching from the non-traveling range to the traveling range, hydraulic pressure is supplied to the friction element to shift the friction element from the released state to the slip state. Since the hydraulic pressure cannot be controlled accurately at times, it is difficult to control the transition to the slip state, the hydraulic pressure becomes too high, the friction element is completely fastened, and the vehicle may start against the driver's will. .

  As another method for suppressing the creep force, an automatic transmission is connected to a so-called interface by fastening another predetermined friction element in addition to the friction element fastened at the time of start-up at the time of transition from the non-travel range to the travel range. It is conceivable to control the lock state. In this method, since only the predetermined friction element is fastened, the hydraulic control is relatively easy, and the output shaft of the automatic transmission is fixed. Even if the engine is kept idle after the shift to the range, it is possible to more reliably prevent the vehicle from starting unexpectedly.

JP 2008-213590 A

  By the way, as described above, when the automatic transmission is interlocked in the travel range and the engine is idled up, it is supplied to the predetermined friction element when the engine is returned to the non-travel range without starting. When the hydraulic pressure is released earlier than the hydraulic pressure supplied to the starting friction element, the interlock is temporarily released, and a state in which the transmission mechanism transmits torque to the drive wheels (a state similar to the first speed) occurs. At the moment of switching from the travel range to the non-travel range, there is a possibility that a forward shock that may give the passenger a sense of incongruity may occur in the vehicle.

  The problem is that the hydraulic pressure is supplied from the hydraulic source to the starting friction element and the predetermined friction element via a manual valve in the hydraulic control circuit, and is switched by the manual valve when switching from the travel range to the non-travel range. In the case where the hydraulic pressure is discharged from both friction elements at the same time, it is conceivable that it is likely to occur.

  The present invention relates to a vehicle powertrain system in which a fluid transmission device is disposed between an engine and a speed change mechanism, and a catalyst device is disposed in an exhaust passage of the engine. Therefore, by interlocking the automatic transmission, it is possible to continue to perform idle-up even after switching from the non-travel range to the travel range, and to prevent shock when returning to the non-travel range again. Is an issue.

  In addition, when the automatic transmission is interlocked so that the idle-up can be continuously executed, it is a second problem to ensure good startability from that state.

  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
A control method for a vehicle powertrain system, comprising: an engine; a transmission mechanism including a plurality of friction elements; and an automatic transmission having a fluid transmission that transmits engine output to the transmission mechanism. When a catalytic device is arranged on the path,
During the idling operation of the engine, when the catalyst device is in an inactive state, an idle up step for increasing the engine speed as compared with when the catalyst device is in an active state;
During execution of the idle up step, when there is a braking request to the vehicle by the driver and the range of the automatic transmission is a travel range, a predetermined friction element other than the starting friction element in the transmission mechanism is set. An interlocking step for bringing the speed change mechanism into an interlocking state by fastening;
An interlock release step for releasing the starting friction element earlier than the predetermined friction element when the range of the automatic transmission becomes a non-traveling range during the execution of the interlock step;
It is characterized by implementing.

The invention according to claim 2 of the present application is the invention according to claim 1,
In the interlock step, the hydraulic pressure supplied to the starting friction element is set to a predetermined reduced hydraulic pressure that is lower than the normal hydraulic pressure in the travel range,
In the interlock release step, the hydraulic pressure supplied to the starting friction element and the predetermined friction element is discharged.

  The normal hydraulic pressure means a hydraulic pressure at which the friction element can transmit a torque necessary for traveling.

Furthermore, the invention according to claim 3 of the present application is the invention according to claim 2,
During the execution of the interlock step, when the braking request to the vehicle by the driver is released, the idle up step is terminated, and the hydraulic pressure supplied to the starting friction element is changed from the predetermined reduced hydraulic pressure. The hydraulic pressure is raised to the normal hydraulic pressure, and the increase in engine speed due to subsequent depression of the accelerator pedal by the driver is suppressed until the hydraulic pressure supplied to the starting friction element reaches the normal hydraulic pressure. .

Furthermore, the invention according to claim 4 of the present application is the invention according to any one of claims 1 to 3,
In the automatic transmission, the hydraulic pressure supplied to the starting friction element and the predetermined friction element is discharged by an operation accompanying an operation of the manual valve provided in the hydraulic control circuit from the travel range to the non-travel range. It is comprised as follows.

Furthermore, the invention according to claim 5 of the present application is
A powertrain system for a vehicle, comprising: an engine; a transmission mechanism including a plurality of friction elements; and an automatic transmission having a fluid transmission that transmits engine output to the transmission mechanism. When a catalytic device is installed,
During idle operation of the engine, when the catalyst device is in an inactive state, an idle increase is performed to increase the engine speed as compared to when the catalyst device is in an active state,
During execution of the idle-up, when there is a braking request to the vehicle by the driver and the range of the automatic transmission is the traveling range, a predetermined friction element other than the starting friction element in the transmission mechanism is engaged. By making the transmission mechanism into an interlock state,
And a controller that releases the starting friction element earlier than the predetermined friction element when the range of the automatic transmission becomes a non-traveling range in the interlock state.

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

  First, according to the first aspect of the present invention, at the time of cold start, since the idling up is continuously performed even after switching from the non-traveling range to the traveling range, activation of the catalyst device is promoted. Furthermore, since the speed change mechanism is brought into the interlock state when switching to the travel range, the torque is not transmitted to the output shaft, so that an unintended start can be avoided.

  Further, when returning from the travel range to the non-travel range, the starting friction element is released earlier than the predetermined friction element that has been fastened to bring the speed change mechanism into the interlock state, so that the speed is temporarily changed. When the mechanism is in the first speed state, it is possible to prevent a forward shock that occurs in the vehicle.

  Further, according to the invention of claim 2, since the hydraulic pressure supplied to the starting friction element is lower than the normal hydraulic pressure in the travel range, the hydraulic pressure supplied to the starting friction element and the predetermined friction element starts to be discharged simultaneously. Even in this case, the starting friction element is released earlier than the predetermined friction element. Therefore, the effect of preventing the shock when the vehicle is returned to the non-running range according to the first aspect of the invention is reliably achieved by the simple hydraulic control of the starting friction element.

  In the invention according to claim 2, since the hydraulic pressure supplied to the starting friction element is lower than the normal hydraulic pressure in the travel range, there is a possibility that slip occurs in the starting friction element when the engine output torque increases. A new problem arises.

  Therefore, according to the third aspect of the present invention, since the increase in the engine speed due to the depression of the accelerator pedal by the driver is suppressed until the hydraulic pressure supplied to the starting friction element reaches the normal hydraulic pressure, It is possible to prevent the occurrence of slipping in the friction element for use and to ensure good startability after the interlock.

  Further, when the driver performs a shift operation from the traveling range to the non-traveling range, a manual valve provided in the hydraulic control circuit is activated along with the shift operation, and is supplied to the starting friction element and the predetermined friction element. If the automatic transmission is configured so that the hydraulic pressure is discharged at the same time, depending on the oil passage of this automatic transmission and the structure of the actuator, the predetermined friction element will start even if the hydraulic pressure discharge starts simultaneously. A state where the starting frictional element is released before the starting frictional element and the starting frictional element can transmit torque, that is, a state similar to the first speed, may temporarily occur. Therefore, there is a possibility that a forward shock that gives the passenger an uncomfortable feeling may occur in the vehicle.

  Therefore, according to the invention of claim 4, even in such a configuration, the hydraulic pressure supplied to the starting friction element is released earlier than the predetermined friction element. It will not be similar to 1st gear. Therefore, it is possible to prevent the occurrence of shock when returning from the travel range to the non-travel range.

  Finally, according to the invention of claim 5, 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 that constitutes a powertrain system 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 of the automatic transmission, and the state of an automatic transmission. It is the schematic of the hydraulic control circuit of the automatic transmission. It is a control block diagram of the same powertrain system. It is a flowchart which shows the control operation of the same powertrain system. It is a flowchart which shows the control action at the time of the interlock control of the powertrain system. It is a flowchart which shows the control action at the time of neutral idle control of the powertrain system. It is a time chart which shows the state of an automatic transmission etc. at the time of operation of N-> D (interlock)-> N in the vehicle to which the same powertrain system is applied. It is a time chart which shows the state of the automatic transmission etc. at the time of operation of N-> D (interlock)-> start in the vehicle to which the same powertrain system is applied. It is a time chart which shows the states of an automatic transmission etc. at the time of operation of N-> D (interlock)-> N in vehicles to which a powertrain system concerning a 2nd embodiment of the present invention is applied. It is a time chart which shows the states of an automatic transmission etc. at the time of operation of N-> D (interlock)-> N in vehicles to which a powertrain system concerning a 3rd embodiment of the present invention is applied.

  Embodiments of a powertrain system control method and a powertrain system according to the present invention will be described below.

(First embodiment)
A vehicle powertrain system according to a first embodiment of the present invention is applied to a front engine / front drive vehicle, and includes a horizontally placed engine (not shown) and a stepped automatic transmission. A catalyst device (not shown) for removing harmful components in the exhaust gas is disposed on the exhaust path of the engine.

  FIG. 1 is a skeleton diagram showing a configuration of an automatic transmission 1. The automatic transmission 1 includes, as main components, a torque converter 2 attached to an engine output shaft A and the torque converter 2 through the torque converter 2. The oil pump 3 is driven by the engine output shaft A, and the transmission mechanism 5 is inputted with the output rotation of the torque converter 2 via the input shaft 4. The oil pump 3 and the transmission mechanism 5 are connected to the input shaft 4. Is housed in the transmission case 6 in a state of being disposed on the shaft center.

  Then, the output rotation of the speed change mechanism 5 is transmitted from the output gear 7 also arranged on the axis of the input shaft 4 to the differential 9 via the counter drive mechanism 8, and the left and right axles 9a, 9b are driven. It has come to be.

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

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

  Further, as a friction element constituting the speed change mechanism 5, a first clutch 40 (“starting friction element” in the claims) and a second clutch 50 are arranged on the torque converter side of the output gear 7. The first brake 60, the second brake 70 (the “predetermined friction element” in the claims), and the third brake 80 are arranged in this order from the torque converter side on the counter-torque converter side of the output gear 7.

  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 so as to be connectable and detachable, and the ring gear 24 and the second gear 24 of the second gear set 20 are connected. The carrier 33 of the third gear set 30 is connected to the transmission case 6 via the second brake 70 so as to be connectable / disengageable, and the ring gear 34 of the third gear set 30 is changed via the third brake 80. It is connected to the machine case 6 so that it can be connected and disconnected.

  With the above configuration, according to the speed change mechanism 5, as shown in FIG. 2, the first and second clutches 40 and 50 and the first, second, and third brakes 60, 70, and 80 are engaged in combination. , P (parking), R (reverse), N (neutral), and D (forward) ranges and 1st to 6th speeds in the D range are achieved. The blank portion in FIG. 2 indicates that the friction element is released. In this embodiment, the first brake 60 is engaged in the P and N ranges.

  FIG. 2 also shows a combination of engagement of friction elements when the interlock control and the neutral idle control of the automatic transmission 1 according to this embodiment are performed. When the interlock control is performed, in addition to the first clutch 40 and the first brake 60 that are engaged at the first speed, the second brake 70 is engaged, whereby the input shaft 4 and the output gear of the transmission mechanism 5 are engaged. An interlock state in which 7 is fixed is realized. On the other hand, when the neutral idle control is performed, the first brake 60 and the second brake 70 are engaged, and the first clutch 40 is brought into a slip state, whereby the output gear 7 of the transmission mechanism 5 is fixed. Interlocked state and neutral idle state are realized.

  The engagement control of each of the friction elements 40 to 80 is performed by hydraulic pressure, and the automatic transmission 1 is provided with a hydraulic control circuit 90 for that purpose, and a schematic configuration thereof is shown in FIG.

  The hydraulic pressure control circuit 90 is supplied with an original pressure from an oil pump 3 (see FIG. 1) driven by the engine output shaft A via the torque converter 2, and a regulator for adjusting the original pressure to a predetermined hydraulic line pressure. A valve 91 and a manual valve 94 that selectively supplies the line pressure to various solenoid valves 93... 93 in the transmission control unit 92 of the hydraulic control circuit 90 according to the selected range. In the R range, hydraulic pressure is selectively supplied to the friction elements 40 to 80 in accordance with the operation of the solenoid valves 93... 93, thereby realizing the first to sixth speeds and the reverse speed.

  A first clutch pressure sensor 95 is provided on a line for supplying hydraulic pressure from the speed change control unit 92 of the hydraulic control circuit 90 to the first clutch 40, and is actually supplied to the first clutch 40 by the sensor 95. Detects hydraulic pressure.

  Further, as shown in FIG. 4, the powertrain system according to this embodiment includes a controller 100, and the controller 100 detects the range of the automatic transmission 1 selected by the driver from the range sensor 101. A signal, a signal from the vehicle speed sensor 102 that detects the vehicle speed of the vehicle, and a signal from the accelerator sensor 103 that detects the amount of depression of the accelerator pedal by the driver are input, and a selected range is selected based on these signals. Further, a gear position according to the driving state of the vehicle is determined, and control signals are output to various solenoid valves 93... 93 in the gear shift control unit 92 of the hydraulic control circuit 90 so that the gear position is realized.

  Further, the controller 100 performs idle-up for promoting activation of the catalyst device at the time of cold start of the engine, and also performs this idle-up after the transition from the P range to the D range before the start of the vehicle. Therefore, in order to perform idle-up even when the catalyst device is still inactive when the vehicle is stopped after running, the first clutch 40 is set in order to idle up even when the vehicle is stopped. Neutral idle control for slipping the transmission mechanism 5 to the neutral idle state is performed.

  For these controls, in addition to the signals from the sensors 101 to 103, a signal from the brake sensor 104 for detecting whether or not the driver depresses the brake pedal, and a catalyst temperature for detecting the temperature of the catalyst device. A signal from the sensor 105 and a signal from the first clutch pressure sensor 95 are input and until the hydraulic pressure supplied to the first clutch 40 reaches a normal hydraulic pressure, that is, the first clutch 40 is engaged by the engagement completion determination control. Until it is determined that the engagement is complete, a control signal is output to the engine speed control device 110 so as to prohibit the engine speed from increasing according to the signal from the accelerator sensor 103 when the accelerator pedal is depressed. To do.

  Next, a 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. In addition, the following operation | movement comprises 1st Embodiment which concerns on the control method of the power train system which concerns on this invention.

  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 105 and the first clutch pressure sensor 95 shown in FIG. 4 are input, and then in step S2, the first brake 60 that is engaged in the P range is engaged. A control signal is output to the hydraulic control circuit 90.

  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, in this embodiment, the idle-up request needs to be activated early when the temperature of the catalyst device indicated by the signal from the catalyst temperature sensor 105 has not risen 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 engine is not in the R range, that is, the P range, a signal is output to the engine speed controller 110 shown in FIG. 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 the engine is in the R range, an idle-up prohibition signal is output to the engine speed controller 110 so as not to idle up 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 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 S11 based on the signal of the brake sensor 104, and when it is determined that the brake is ON, in step S14, described later. The interlock control 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. Then, a signal is output to the engine speed control device 110 so as to prohibit idling 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 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 a signal from the brake sensor 104. If it is determined in step S15 that the brake is ON, in step S16, Neutral idle control, which will be described later, is executed, and when it is determined in step S15 that the brake is not ON, a signal is output to the engine speed control device 110 so as to prohibit idling up.

  Next, the operation at the time of 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 control circuit 90 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 the normal hydraulic pressure.

  If the brake pedal is not depressed in the D range (brake OFF), it is determined in step S23 that it is not in the N range, it is determined in step S24 that the brake is OFF, and in step S25, the engine speed is determined. A signal is output to the control device 110 so as to end the idle up. Thereby, the idle up in D range is complete | finished.

  Next, in step S26, the hydraulic pressure supplied to the first clutch 40 is increased from the predetermined reduced hydraulic pressure to the normal hydraulic pressure, and in step S27, a control signal is output to the hydraulic control circuit 90 so as to release the second brake 70. To do. Accordingly, when the first clutch 40 and the first brake 60 are engaged, the transmission mechanism 5 is released from the interlock state, and the automatic transmission 1 enters the first speed state.

  Further, in step S28, based on the signal from the first clutch pressure sensor 95, it is determined whether the hydraulic pressure actually supplied to the first clutch 40 has increased to the normal hydraulic pressure, and until the increase is determined to be complete. In step S29, a control signal is sent to the engine speed control device 110 so that the engine speed does not increase according to the signal from the accelerator sensor 103 even if the amount of accelerator depression increases as the driver depresses the accelerator pedal. Is output. The normal hydraulic pressure is a fastening hydraulic pressure that can transmit a torque necessary for traveling.

  When the first clutch 40 rises to the normal hydraulic pressure, it is determined in step S28 that the raising is completed, and in step S30, the vehicle is increased to a predetermined vehicle speed (for example, 3 km / h) or more based on a signal from the vehicle speed sensor 102. If it is determined whether or not the vehicle speed has reached or exceeded the predetermined vehicle speed, a neutral idle execution condition flag is set (ON) in step S31, 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 S32, the first clutch 40 is released, and in step S33. Then, a control signal is output to the hydraulic control circuit 90 so as to release the second brake 70. As a result, the hydraulic pressure is simultaneously discharged from both friction elements by the manual valve 94 of the hydraulic control circuit 90, the transmission mechanism 5 is released from the interlock state, and the automatic transmission 1 is in the N range state, but the idle up continue. Thereafter, the process returns to the main routine of FIG.

  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 hydraulic control is performed 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. A control signal is output to the circuit 90.

  As a result, if there is no particular problem, the transmission mechanism 5 enters the neutral idle state and the interlock state while continuing the idle-up, but for confirmation, the transmission mechanism 5 actually completes the interlock in step S44. When it is determined whether or not it is completed, in step S45, a signal is output to the engine speed control device 110 so as to idle up.

  This interlock completion determination is performed by, for example, providing a second brake pressure sensor (not shown) for detecting the hydraulic pressure supplied to the second brake 70 and inputting an output signal from this sensor to the controller 100. The time when the hydraulic pressure actually supplied to the second brake 70 reaches the normal hydraulic pressure may be determined as an interlock establishment.

  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 perform idle-up in an interlocked state reliably, so that the engine rotates at a high speed when the interlock is not established, and the vehicle starts against the driver's will due to a large creep force Is avoided.

  Next, in step S46, it is determined whether or not the brake is OFF from the signal of the brake sensor 104, that is, whether or not the driver has released the brake pedal. Until the brake is determined to be OFF in step S46, the speed change mechanism. Idle-up is continued while 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, in step S47, a signal is output to the engine speed control device 110 to end idle-up, and in step S48, While releasing 2 brake 70, a control signal is output to the hydraulic control circuit 90 so that the 1st clutch 40 may be fastened at step 49. FIG. As a result, the neutral idle state and the interlock state are released and the transmission mechanism 5 enters the first speed state and starts 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.

  When the vehicle stops in the D range after traveling, it is idled up in the neutral idle state (only the output gear 7 is fixed), not in the interlock state (the input shaft 4 and the output gear 7 are fixed). In this case, since the hydraulic pressure supplied to the first clutch 40 is reduced to control from the engaged state to the slip state, the hydraulic control is relatively easy and the neutral idle state (the first clutch 40 is Since the load on the engine is smaller than in the interlock state (loss is generated due to the viscosity of the hydraulic oil in the torque converter 2) in the slip friction between the friction plates, the catalyst device can be activated more quickly. The smaller the engine load, the smaller the force that pushes down the piston of the engine. This is because it is possible to favorable combustion.

  As described above, when there is an idle-up request at the time of cold start of the engine or the like, even after the driver depresses the brake pedal and switches the automatic transmission 1 from the P range to the D range, While being depressed, idling up is continuously performed, and activation of the catalyst device is promoted. Further, an increase in creep force caused by idling up in a state where the automatic transmission 1 can travel (first speed state) is dealt with by interlocking the transmission mechanism 5 of the automatic transmission 1, The start of the vehicle against the driver's will is prevented.

  Further, the hydraulic control circuit 90 is configured such that the first clutch 40 and the second brake 70 are simultaneously discharged by the operation of the manual valve 94 accompanying the shift operation from the driving range to the non-driving range by the driver. In this case, since the first clutch 40 is released earlier than the second brake 70 by engaging the hydraulic pressure supplied to the first clutch 40 during the interlock control as a predetermined reduced hydraulic pressure lower than the normal hydraulic pressure, The state in which the second brake 70 is released and the first clutch 40 can transmit torque, that is, the automatic transmission is not in the first speed state. Therefore, it is possible to prevent a forward shock that gives a sense of discomfort to the occupant from occurring at the moment of switching from the travel range to the non-travel range.

  Next, a change in the vehicle state when the vehicle to which the powertrain system according to the first embodiment is applied is operated will be described.

  FIG. 8 is a time chart showing the state of the vehicle when the engine is returned to the N range again after the ND operation immediately after the cold start of the engine.

  Since the vehicle is initially in the N range, only the first brake 60 is engaged in the speed change mechanism 5 (S2), the vehicle stops when the brake is ON, and the idle up request is ON immediately after the cold start of the engine. The engine is rotating at the idle-up rotation speed (S7). At this time, since the first clutch 40 is disengaged, the input shaft 4 of the transmission mechanism 5 is rotated by the torque converter 2 and is rotating at a speed substantially equal to the engine speed.

  If the driver performs an ND operation during idling up in the N range, the interlock control is performed while the idling up is continued (S14), the second brake 70 is engaged, and the first clutch 40 is fastened with a predetermined reduced oil pressure lower than the normal oil pressure (S21, S22), and the speed change mechanism 5 enters the interlock state. At this time, the rotation of the input shaft 4 is decelerated as the hydraulic pressure supplied to the first clutch 40 increases.

  When the driver performs a shift operation to return to the N range in this interlock state, the first clutch 40 and the second brake 70 are instructed to be released (S32, S33), and the hydraulic pressure is applied from both friction elements by the manual valve 94. However, since the first clutch 40 has been engaged at a predetermined reduced hydraulic pressure lower than the normal hydraulic pressure until then, the hydraulic pressure supplied to the first clutch 40 is the hydraulic pressure supplied to the second brake 70. The first clutch 40 is released first by being discharged earlier.

  Therefore, the speed change mechanism 5 is released from the interlock state while continuing the idle-up without causing a state in which the first clutch 40 can transmit torque temporarily (a state similar to the first speed). When the first clutch 40 is released and the interlock is released, the input shaft speed increases 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, idle-up in the D range can be performed satisfactorily without causing an unintended start or the like in order to promote activation of the catalyst device.

  The hydraulic pressure is supplied to the first clutch 40 and the second brake 70 via the manual valve 94 in the hydraulic control circuit 90 from the hydraulic pressure source, and the manual valve 94 is switched from the travel range to the non-travel range. Therefore, even when the hydraulic pressure is discharged from both frictional elements simultaneously, it is possible to prevent a shock when returning to the N range again.

  FIG. 9 is a time chart showing the state of the vehicle when the vehicle is stopped for a while after the ND operation immediately after the cold start of the engine.

  Since the initial N range to the interlock state in the D range after ND operation is the same as in the case of FIG. 8, the description is omitted.

  When the driver removes his / her foot from the brake pedal in the interlock state in the D range, the idle up is finished (S25), and the engine speed is reduced. In addition, the second brake 70 is released and the hydraulic pressure supplied to the first clutch 40 is instructed to increase from a predetermined reduced hydraulic pressure to a normal hydraulic pressure (S26, S27), but is actually supplied to the first clutch 40. The hydraulic pressure (hereinafter referred to as “actual hydraulic pressure”; see the arrow in FIG. 9) does not increase to the normal hydraulic pressure immediately after being instructed, but has a time lag until the normal hydraulic pressure is reached.

  During this time lag, even if the driver depresses the accelerator pedal, until the actual hydraulic pressure of the first clutch 40 reaches the normal hydraulic pressure, which is the engagement hydraulic pressure that can transmit the torque required during traveling, according to the accelerator depression amount. The engine speed does not increase (S29). If the engine speed is not limited to increase depending on the accelerator depression amount, the engine rotation speed depends on the accelerator depression amount as shown by the dotted line graph in FIG. 9 (see the arrow “no increase limitation”). Rises.

  When the hydraulic pressure supplied to the first clutch 40 has been increased to the normal hydraulic pressure, the automatic transmission 1 becomes similar to the first gear, and the vehicle can start in response to the driver's depression of the accelerator pedal. . Thereafter, when the vehicle speed exceeds a predetermined vehicle speed, a neutral idle execution condition flag is set (S31).

  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. Can be promoted. Further, when the driver lifts his / her foot from the brake pedal in the interlock state, the hydraulic pressure supplied to the first clutch 40 is low by controlling the engine speed not to increase regardless of the accelerator depression amount. Since slip in the first clutch 40 that may occur when the engine output torque increases in the state can be prevented, good startability from the interlock state can be ensured.

(Second Embodiment)
Since the vehicle powertrain system according to the second embodiment of the present invention has the same configuration as that of the vehicle powertrain system according to the first embodiment, FIG. 1 to FIG. 5 and FIG. Description is omitted.

  FIG. 10 is a time chart showing the state of the vehicle when it is returned to the N range after the ND operation immediately after the cold start of the engine, and FIG. 8 of the first embodiment is different from the N range. It differs only in the point of the control method of the hydraulic pressure supplied to the friction element when returned to.

  In the case of the second embodiment, when the driver performs the range operation from the N range to the D range, the controller 100 causes the hydraulic control circuit 90 to engage both the first clutch 40 and the second brake 70 with the normal hydraulic pressure. Output a control signal. When the driver performs a shift operation to the N range, a control signal is sent to the hydraulic control circuit 90 so as to reduce the hydraulic pressure supplied to each friction element in order to release the first clutch 40 and the second brake 70. The hydraulic pressure reduction speed of the hydraulic pressure supplied to the first clutch 40 (arrow c in FIG. 10) is the hydraulic pressure reduction speed of the hydraulic pressure supplied to the second brake 70 (arrow d in FIG. 10). ) Is controlled to be faster.

  According to this, since the hydraulic pressure actually supplied to the first clutch 40 is released earlier than the hydraulic pressure supplied to the second brake 70, it is returned to the N range for the same reason as in the first embodiment. The shock at the time can be prevented.

(Third embodiment)
The configuration of the powertrain system for a vehicle according to the third embodiment of the present invention is almost the same as that of the first embodiment, and the description of FIGS. 1 to 5 and 7 also applies to the third embodiment. Common.

  FIG. 11 is also a time chart showing the state of the vehicle when it is returned to the N range after the ND operation immediately after the cold start of the engine, and FIG. 8 of the first embodiment is different from the N range. It differs only in the point of the control method of the hydraulic pressure supplied to the friction element when returned to.

  In the case of the third embodiment, when the driver operates the range from the N range to the D range, the controller 100 causes the hydraulic control circuit 90 to engage both the first clutch 40 and the second brake 70 with the normal hydraulic pressure. Output a control signal. When the driver performs a shift operation to the N range, a control signal is sent to the hydraulic control circuit 90 so as to reduce the hydraulic pressure supplied to each friction element in order to release the first clutch 40 and the second brake 70. When the hydraulic pressure is reduced, control is performed so that the second brake 70 is released (arrow f in FIG. 11) after a predetermined time has elapsed after the first clutch 40 is released (arrow e in FIG. 11). Yes.

  According to this, since the hydraulic pressure actually supplied to the first clutch 40 is released earlier than the hydraulic pressure supplied to the second brake 70, the third embodiment is also for the same reason as the first embodiment. , The shock when returning to the N range can be prevented.

  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, it is possible to continue to perform idle-up even after switching from the non-traveling range to the traveling range, and to prevent shock when returning to the non-driving range again. There is a possibility of being suitably used in the industrial field.

1 Automatic transmission 2 Torque converter (fluid transmission)
5 Transmission mechanism 40 Friction element for starting (first clutch)
70 Predetermined friction element (second brake)
100 controller

Claims (5)

A control method for a vehicle powertrain system, comprising: an engine; a transmission mechanism including a plurality of friction elements; and an automatic transmission having a fluid transmission that transmits engine output to the transmission mechanism. When a catalytic device is arranged on the path,
During the idling operation of the engine, when the catalyst device is in an inactive state, an idle up step for increasing the engine speed as compared with when the catalyst device is in an active state;
During execution of the idle up step, when there is a braking request to the vehicle by the driver and the range of the automatic transmission is a travel range, a predetermined friction element other than the starting friction element in the transmission mechanism is set. An interlocking step for bringing the speed change mechanism into an interlocking state by fastening;
An interlock release step for releasing the starting friction element earlier than the predetermined friction element when the range of the automatic transmission becomes a non-traveling range during the execution of the interlock step;
A control method for a powertrain system, characterized in that In the interlock step, the hydraulic pressure supplied to the starting friction element is set to a predetermined reduced hydraulic pressure that is lower than the normal hydraulic pressure in the travel range,
2. The method of controlling a power train system according to claim 1, wherein in the interlock release step, the hydraulic pressure supplied to the starting friction element and the predetermined friction element is discharged. During the execution of the interlock step, when the braking request to the vehicle by the driver is released, the idle up step is terminated, and the hydraulic pressure supplied to the starting friction element is changed from the predetermined reduced hydraulic pressure. The hydraulic pressure is raised to the normal hydraulic pressure, and the increase in engine speed due to subsequent depression of the accelerator pedal by the driver is suppressed until the hydraulic pressure supplied to the starting friction element reaches the normal hydraulic pressure. The powertrain system control method according to claim 2. In the automatic transmission, the hydraulic pressure supplied to the starting friction element and the predetermined friction element is discharged by an operation accompanying an operation of the manual valve provided in the hydraulic control circuit from the travel range to the non-travel range. The powertrain system control method according to any one of claims 1 to 3, wherein the control method is configured as described above. A powertrain system for a vehicle, comprising: an engine; a transmission mechanism including a plurality of friction elements; and an automatic transmission having a fluid transmission that transmits engine output to the transmission mechanism. When a catalytic device is installed,
During idle operation of the engine, when the catalyst device is in an inactive state, an idle increase is performed to increase the engine speed as compared to when the catalyst device is in an active state,
During execution of the idle-up, when there is a braking request to the vehicle by the driver and the range of the automatic transmission is the traveling range, a predetermined friction element other than the starting friction element in the transmission mechanism is engaged. By making the transmission mechanism into an interlock state,
A power train system comprising: a controller that releases the starting friction element earlier than the predetermined friction element when the range of the automatic transmission becomes a non-traveling range in the interlock state.