JP6031911B2 - Powertrain system control method and powertrain system - Google Patents

Description

  The present invention relates to a control method and a powertrain system for a vehicle such as an automobile, particularly a vehicle including an engine and an automatic transmission, and belongs to the field of control technology for a vehicle powertrain system.

  In general, in a vehicle such as an automobile, a catalyst device is installed in an exhaust path of an engine in order to remove harmful components in the exhaust gas. However, since this catalyst device does not function effectively in a low temperature state, it is necessary to quickly increase the temperature and activate it when the engine is cold started. 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 traveling range such as the D-range when the vehicle is equipped with an automatic transmission having a fluid transmission device such as a torque converter, the creep force is increased because the idle rotational speed is high. There is a risk that the vehicle will start unexpectedly by overcoming the braking request by the driver's depression of the brake pedal before the start of traveling. Therefore, conventionally, the early activation control of the catalyst device by idling up at the cold start is performed only in the non-traveling range such as the P range and the N range, and is ended when the driver operates the traveling range. It was.

  On the other hand, in order to respond to the recent tightening of exhaust gas regulations, for example, it is required to further shorten the activation time of the catalyst device and enhance the catalyst activation promoting effect. Therefore, it is considered that when the shift is made from the non-travel range to the travel range, the creep force is suppressed so that the idle up control is not interrupted and is continued after the shift to the travel range.

  Therefore, for example, in Patent Document 1, as a method of suppressing the creep force in the travel range, control for limiting transmission of engine output to drive wheels by slipping a starting friction element fastened in the travel range (so-called “so-called”). A method for performing neutral idle control is disclosed. Specifically, by controlling the turbine rotational speed that is the differential rotation between the input-side rotational speed and the output-side rotational speed of the starting friction element (the output-side rotational speed is 0 because the vehicle is stopped), The slip amount of the friction element is controlled to the target value. When the slip amount reaches the target value, the idle up control is started.

JP 2008-213590 A

  By the way, in the neutral idle control as described above, if the idle-up control is started in a state where the hydraulic pressure supplied to the starting friction element is high and the slip amount is small, the vehicle may start against the driver's braking intention. There is. Similarly, when the idle up control is started in a state where the supplied hydraulic pressure is low and the slip amount is large, there is a problem that the start-up responsiveness deteriorates due to delay in fastening of the start-up friction element at the time of start-up. Therefore, it is necessary to carefully control the predetermined slip state.

  And this problem is a state in which the travel range has already been selected, for example, when neutral idle control is performed when shifting from the non-travel range to the travel range in a stopped state, for example, when the vehicle is stopped after traveling. This can occur in the same way when neutral idle control is performed.

  In order to avoid such a problem, it is conceivable that the idle-up control is started after the starting friction element reaches a predetermined slip state. However, since the hydraulic pressure cannot be controlled with high accuracy particularly during cold start where the viscosity of ATF is large, it is difficult to control the transition to a predetermined slip state, and further careful control is required. Therefore, it takes time for the starting frictional element to reach the predetermined slip state from the engaged state, and the start of the idle up control is delayed, so that the catalyst activation promoting effect cannot be sufficiently enhanced.

  Therefore, the present invention does not cause problems such as starting against the driver's willingness to brake or deterioration of responsiveness of starting, and the activation time of the catalyst device is shortened, and the catalyst activation promoting effect is excellent. It is an object of the present invention to provide a method for controlling a powertrain system of a vehicle and a powertrain system.

  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.

According to a first aspect of the present invention, there is provided a power train for a vehicle including an engine, a transmission mechanism including a plurality of friction elements, and an automatic transmission having a fluid transmission device that transmits engine output to the transmission mechanism. A control method for a system, wherein a catalyst device is disposed on an exhaust path of the engine, and when there is a braking request for the vehicle by a driver in a stopped state in a travel range, the catalyst device an idle or not idle-up request determining step determines whether up a request for the activation accelerating, when it is determined that the idle-up request in the idle-up request determining step, the starting friction in the transmission mechanism It was determined that there was an idle-up request as well as a neutral idle step that causes the element to transition from the engaged state to the predetermined slip state. To come determines the interlocking steps of the speed change mechanism and interlocking condition by engaging a predetermined frictional elements other than the starting frictional element in the transmission mechanism, the speed change mechanism whether the interlocking condition An interlock determination step, and when it is determined in the interlock determination step that the speed change mechanism is in the interlock state , the idle speed is increased compared to when the catalyst device is in the active state, and the rotation speed is increased. And an idle up step for holding

  Here, the predetermined slip state is a state where the differential rotation between the input side rotational speed and the output side rotational speed of the starting friction element is the predetermined rotational speed.

  The invention according to claim 2 is the method according to claim 1, wherein the interlock step includes an idle-up step after the start-up friction element is brought into a predetermined slip state by the neutral idle step. It is carried out until the end.

According to a third aspect of the present invention, there is provided a powertrain system for a vehicle including an engine, a speed change mechanism including a plurality of friction elements, and an automatic transmission having a fluid transmission for transmitting engine output to the speed change mechanism. When the catalyst device is disposed on the exhaust path of the engine and the driver makes a braking request to the vehicle in a stopped state in the travel range, activation of the catalyst device is promoted. When it is determined whether there is an idle up request for the engine, and when it is determined that there is an idle up request, the starting frictional element in the speed change mechanism is shifted from the engaged state to the predetermined slip state. When the determination is made, the transmission mechanism is interlocked by fastening a predetermined friction element other than the starting friction element in the transmission mechanism. And, wherein the transmission mechanism is determined whether the interlocking condition, the sometimes shift mechanism is determined to be interlocked state, increases the idle speed than when the catalytic converter is active And a controller for holding the rotational speed.
The invention according to claim 4 is the method according to claim 1 or 2, wherein the predetermined friction element is a hydraulic clutch, and is supplied to the predetermined friction element in the interlock determination step. When the hydraulic pressure reaches a predetermined hydraulic pressure, it is determined that the speed change mechanism is in an interlock state.

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

  First, according to the first aspect of the present invention, the transition of the starting friction element to the predetermined slip state is performed with particular care at the time of cold starting, for the purpose of preventing the deterioration of the response of the starting. However, even if the idle speed is increased during the control of the starting friction element to the predetermined slip state, the vehicle is started against the braking intention of the driver. Never do. Therefore, before the control to the predetermined slip state is completed, the idle speed of the engine can be increased when the transmission mechanism is in the interlock state, the activation time of the catalyst device is shortened, and the catalyst The activation promoting effect can be sufficiently enhanced.

  According to the second aspect of the present invention, when the starting friction element is fastened from a predetermined slip state and started, the interlock state of the speed change mechanism is also released. When the starting friction element is fastened until it is completely released, the transmission of the shock to the vehicle body due to the fastening friction element being fastened is reduced.

  Furthermore, a so-called hill hold function is obtained while the vehicle is stopped in a predetermined slip state on an uphill / downhill road or at the moment of braking release, and the vehicle is prevented from sliding forward or backward.

  According to the third aspect of the invention, the same effect as that of the first aspect of the invention can be obtained.

1 is a skeleton diagram of an automatic transmission constituting a powertrain system according to an 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 an automatic transmission, and the state of an automatic transmission. It is the schematic of the hydraulic control circuit of an automatic transmission. It is a control block diagram of a powertrain system. It is a flowchart which shows the control operation of a powertrain system. It is a flowchart which shows the control action at the time of the interlock control of a powertrain system. It is a flowchart which shows the control action at the time of neutral idle control of a powertrain system. 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.

  A vehicle powertrain system according to an 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 the configuration of the automatic transmission 1.
The automatic transmission 1 includes a torque converter 2 attached to the engine output shaft A, an oil pump 3 driven to the engine output shaft A via the torque converter 2, and a torque converter 2 (“fluid transmission” in the claims). The apparatus includes a speed change mechanism 5 and the like to which the output rotation of the device “) is input via the input shaft 4. The automatic transmission 1 is housed in the transmission case 6 with the oil pump 3 and the transmission mechanism 5 disposed on the axis of the input shaft 4.

  Then, the output rotation of the speed change mechanism 5 is transmitted from the output gear 7 also disposed 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 and 9b are driven. The

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

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

  The transmission mechanism 5 includes a first clutch 40 (“starting friction element” in the claims) and a second clutch 50 on the torque converter side of the output gear 7 as friction elements. Furthermore, a first brake 60, a second brake 70 (“predetermined friction element” in the claims), and a 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 the sun gears 11, 21, and 31 and a plurality of pinions 12, 22 that mesh with the sun gears, respectively. , 32, and carriers 13, 23, 33 for supporting these pinions, respectively, and ring gears 14, 24, 34 meshed with the pinions 12, 22, 32, respectively.

  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 carrier of the second gear set 20. 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.

  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 via the first clutch 40 so as to be connectable and detachable. Further, the carrier 23 of the second gear set 20 is connected to the input shaft 4 via the second clutch 50 so as to be connectable and disconnectable.

  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 connected and disconnected. The ring gear 24 of the second gear set 20 and the carrier 33 of the third gear set 30 are connected to the transmission case 6 via the second brake 70 so as to be connected and disconnected. The ring gear 34 of the third gear set 30 is connected to the transmission case 6 via the third brake 80 so as to be connectable and detachable.

  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 range and the N range.

  FIG. 2 also shows a combination of engagement of friction elements during the interlock control and the neutral idle control of the automatic transmission 1 according to the present embodiment. As shown in FIG. 2, in addition to the first clutch 40 and the first brake 60 that are engaged at the first speed, the interlock control that engages the second brake 70 is performed. By this control, an “interlock state” in which the output gear 7 of the speed change mechanism 5 is fixed is realized, and the first clutch 40 is engaged, so that the input shaft 4 is also fixed.

  On the other hand, the neutral idle control shown in FIG. 2 realizes a “neutral idle state” in which the first clutch 40 is brought into a predetermined slip state from the first speed state in which the first clutch 40 and the first brake 60 are engaged. . In this “predetermined slip state” (hereinafter referred to as a slip state), the differential rotation between the input side rotational speed and the output side rotational speed of the first clutch 40 becomes the predetermined target slip rotational speed.

  Further, when the first clutch 40 is in the slip state and the first brake 60 is engaged and the second brake 70 is engaged, the output gear 7 of the transmission mechanism 5 is fixed in addition to the neutral idle state. Interlocked state is realized.

  When the first clutch 40 is engaged when starting from the neutral idle state, the driver may feel a shock due to the engagement. At this time, when the second brake 70 is released at the start from the neutral idle state and the interlock state, the hydraulic pressure (actual oil pressure) actually supplied to the second brake 70 is reduced and the interlock state is completely completed. Since the first clutch 40 is engaged until it is released, the shock due to this engagement is alleviated. Further, at this time, the hill hold function is obtained while the vehicle is stopped on the uphill / downhill road or when the driver releases the brake pedal on the up / downhill road, and the vehicle is prevented from sliding forward or backward.

  The fastening control of each friction element 40-80 is performed by hydraulic pressure. 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 original pressure is supplied to the hydraulic control circuit 90 from an oil pump 3 (see FIG. 1) driven by the engine output shaft A via the torque converter 2. The hydraulic control circuit 90 selectively selects a regulator valve 91 that adjusts the original pressure to a predetermined hydraulic line pressure, and various solenoid valves 93... 93 in the shift control unit 92 of the hydraulic control circuit 90 according to the selected range. And a manual valve 94 for supplying line pressure. And in D range and R range, according to operation | movement of solenoid valve 93 ... 93, hydraulic pressure is selectively supplied to each friction element 40-80, and as demonstrated in FIG. And reverse speed is realized.

  A second brake pressure sensor 95 is provided on a line for supplying hydraulic pressure from the shift control unit 92 of the hydraulic control circuit 90 to the second brake 70, and is supplied to the second brake 70 by the sensor 95. Detect the hydraulic pressure.

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

  Here, the controller 100 performs idle-up control for promoting activation of the catalyst device when the engine is cold-started. In addition, the controller 100 performs an interlock control for setting the transmission mechanism 5 in an interlock state in order to perform the idle-up control even after the transition from the P range to the D range before the vehicle starts.

  Further, the controller 100, for example, when the vehicle stops once after traveling, and when the catalyst device is still inactive, causes the first clutch 40 to slip to perform the idle-up control even when the vehicle is stopped. Neutral idle control is performed to set 5 to the neutral idle state. In particular, when performing this neutral idle control, control for engaging the second brake 70 is performed, and control for starting idle-up is performed when the second brake 70 is engaged and in the interlock state.

  For these controls, in addition to the signals from the sensors 101 to 103, the controller 100 also receives a signal from the brake sensor 104 that detects whether the driver depresses the brake pedal and the temperature of the catalyst device. A signal from the catalyst temperature sensor 105 to be detected and a signal from the second brake pressure sensor 95 are input.

Next, the idle-up control by the controller 100 will be described with reference to the flowchart of FIG.
The following control operation constitutes an embodiment according to the control method of the powertrain system according to the present invention. In each step of the flowchart, “N range” means a non-traveling range, and includes an N (neutral) range and a P (parking) range.

  The controller 100 starts a 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 (Ig-ON). First, in step S1, signals from the sensors 101 to 105 and the second brake pressure sensor 95 shown in FIG. Next, in step S2, a control signal is output to the hydraulic control circuit 90 so as to engage the first brake 60 that is engaged in the P range.

  Next, in step S3, based on the signal from the vehicle speed sensor 102, it is determined 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 S4 whether or not there is an idle up request for increasing the engine idle speed.

  Here, in this embodiment, when the temperature of the catalyst device indicated by the signal output from the catalyst temperature sensor 105 has not risen to the activation temperature, it is determined that there is an idle up request. Or since the temperature of a catalyst apparatus rises with the elapsed time after engine starting, it can also be determined whether there exists an idle up request | requirement based on the elapsed time.

  Immediately after the engine is started, the catalyst temperature is low, and it is determined that there is an idle up request. Therefore, in the next step S5, it is determined whether or not the D range has been selected at the time of stopping determination in step S3.

  Further, the P range is selected immediately after the engine is started. Therefore, in step S5, it is determined that the vehicle is not in the D range at the time of stoppage determination. In the next step S6, it is determined whether the current range is the R range. A signal is output to the engine speed control device 110 shown in FIG. 4 so as to maintain the engine idle speed, that is, to idle up. 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. If it is determined in step S6 that the range is the R range, the process proceeds to step S9 without idling up.

  Then, while performing idle-up in the state of the P range, it is determined in step S9 that it was not the N range by determining whether or not the range was the N range at the time of stopping determination in step S3. Next, in step S10, based on the signal from the range sensor 101, whether or not an ND operation has been performed, that is, whether or not the driver has performed a shift operation from the N range (including the P range) to the D range. Determine whether or not. And until it determines with ND operation having been performed, the idle up in P range is continued.

  Here, when the ND operation is performed while performing the idle up in the state of the P range, it is determined in step S10 that the ND operation has been performed, and the idle up is continued in step S14. The process proceeds to an interlock control subroutine which will be described later.

  On the other hand, when it is determined that the catalyst device is still inactive and there is an idle up request in step S4 when the vehicle is stopped after traveling, the vehicle is in the D range when the vehicle is stopped. At the time of the determination, it is determined that the range is the D range, the driver's braking request is confirmed in step S15 (brake ON), and in step S16, the process proceeds to a neutral idle control subroutine which will be described later. If it is determined in step S15 that the driver has released the brake pedal, the process returns without idling up.

Next, the interlock control by the controller 100 is demonstrated, referring the flowchart of 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 of the automatic transmission 1 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 supplied when the vehicle travels.

  If the brake pedal is not depressed in the D range, it is determined in step S23 that it is not in the N range, and it is determined in step S24 that the brake is OFF. In step S25, a signal is output to the engine speed 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 first clutch 40 is engaged with 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. As a result, only the first clutch 40 and the first brake 60 are engaged, and as shown in FIG. 2, the transmission mechanism 5 is released from the interlock state and 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). If it is determined that the vehicle speed is equal to or greater than the predetermined vehicle speed, a neutral idle execution condition flag is set (flag ON) in step S29, and the process returns to the main routine of FIG.

  On the other hand, if the driver performs a shift operation to the N range while continuing to idle up in the interlock state, it is determined in step S23 that the vehicle is in the N range. In step S30, the first clutch 40 is released, and in step S31, a control signal is output to the hydraulic pressure 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.

  At this time, since the first clutch 40 is released earlier than the second brake 70 that has been engaged, a forward shock that may occur in the vehicle is prevented by temporarily setting the transmission mechanism 5 to the first speed state. . In step S22, the first clutch 40 is engaged at a predetermined reduced hydraulic pressure lower than the normal hydraulic pressure, so the first clutch 40 is released before the second brake 70, and this shock prevention effect is achieved. Further improve.

  Then, the speed change mechanism 5 is released from the interlock state, becomes in the N range state, and continues to idle up. Thereafter, the process returns to the main routine of FIG.

Next, neutral idle control by the controller 100 will be described with reference to the flowchart of FIG.
First, in step S41, it is determined whether or not a neutral idle execution condition is satisfied. When the process shifts to the neutral idle control subroutine, the vehicle travels once and the flag is set in step S29. Therefore, it is determined in step S41 that this execution condition is satisfied.

  Next, in step S42, the second brake 70 is engaged, and in step S43, the hydraulic pressure of the first clutch 40 is reduced to a predetermined slip pressure and a control signal is output to the hydraulic pressure control circuit 90 so as to be in a slip state. . The “predetermined slip pressure” is a hydraulic pressure lower than a predetermined reduced hydraulic pressure for engaging the clutch described in FIG.

  Next, in step S44, it is determined whether or not the second brake 70 is engaged, that is, whether or not the interlock state is actually established in the transmission mechanism 5. If it is determined that the condition is established, a signal is output to the engine speed control device 110 so as to idle up in step S45.

  At this time, whether or not the interlock state is established is determined based on whether or not the actual hydraulic pressure of the second brake 70 has reached the interlock determination pressure based on the signal of the second brake pressure sensor 95. Do. This “interlock determination pressure” is a hydraulic pressure at which it can be determined that the second brake 70 is engaged, and even if a hydraulic pressure higher than the interlock determination pressure is supplied to the second brake 70 when the engaged state is maintained. Good.

  On the other hand, if the actual hydraulic pressure of the second brake 70 has not reached the interlock determination pressure, it is determined in step S44 that the interlock state is not established. Then, after reaching the interlock determination pressure, the process proceeds to step S45, and a signal is output to the engine speed control device 110 so as to idle up.

  Next, in step S46, it is determined based on the signal from the brake sensor 104 whether or not the driver has released the brake pedal. Until it is determined that the brake pedal is released (brake OFF), idling up is continued in the interlock state.

  When it is determined in step S46 that the brake pedal has been released, in step S47, a signal is output to the engine speed control device 110 so as to end idle-up, and in step S48, the second brake 70 is released. In step S49, a control signal is output to the hydraulic control circuit 90 so that the first clutch 40 is engaged. As a result, the neutral idle state is canceled and the transmission mechanism 5 enters the first speed state, and starts in response to the driver's depression of the accelerator pedal. In order to secure the above-mentioned effect that the shock at the time of engagement of the first clutch 40 is alleviated when starting from the neutral idle state, the actual hydraulic pressure of the second brake 70 is gradually reduced in step S48. You may control so that it may fall.

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

  FIG. 8 is a time chart showing the state of the vehicle when the vehicle is once traveled, temporarily stopped in the D range and then started again. Hereinafter, a change in the vehicle state when the vehicle to which the powertrain system according to this embodiment is applied is operated will be described with reference to FIG.

  When the vehicle is traveling in the D range and the driver depresses the brake pedal to stop the vehicle, the neutral idle (N-idle in FIG. 8) execution condition flag is already set (S41).

  Then, the second brake 70 is engaged (S42), and a control signal for reducing the first clutch pressure to a predetermined slip pressure is transmitted (S43). At this time, idle up is not performed until the second brake 70 is actually engaged and the interlocking state of the transmission mechanism 5 is realized (S44). Then, based on the signal from the second brake pressure sensor 95, when the actual hydraulic pressure of the second brake 70 reaches the interlock determination pressure and is determined to be in the interlock state (S44), the symbol a in FIG. As shown, idle up is started, and the engine speed increases to the idle up speed (S45).

  Thereafter, the first clutch 40 reaches the slip state. When the vehicle stops, the output side rotational speed of the first clutch 40 is 0, and therefore the actual hydraulic pressure (not shown) of the first clutch 40 is such that the rotational speed of the input shaft 4 (input shaft rotational speed) is the target slip. When the rotational speed is reached, a predetermined slip pressure is reached. At this time, since the first clutch 40 is slipping, the turbine 3c as the input shaft of the speed change mechanism 5 is rotated at a speed substantially the same as the engine speed.

  Next, when the driver releases the brake pedal (S46), the idle-up is finished as indicated by the symbol b (S47), and the engine speed decreases. Then, the second brake 70 is released (S48), the first clutch 40 is engaged (S49), the speed change mechanism 5 becomes the first speed, and the vehicle starts.

  At this time, as indicated by reference sign c, the first clutch 40 is engaged until the interlock state is completely released, so that the shock felt by the driver when the first clutch 40 is engaged is alleviated. . If the vehicle is on an uphill / downhill road, the hill hold function is obtained at the moment when the driver releases the brake pedal, and the vehicle is prevented from sliding forward or backward.

  In this embodiment, the engagement of the second brake 70 is maintained until the idle-up is completed. For example, when the input shaft rotational speed reaches the target slip rotational speed, the second brake 70 is engaged as indicated by reference sign d. The brake 70 may be released.

  As described above, in the control of the controller 100 described in this embodiment, when there is an idle up request at the time of cold start of the engine, the driver depresses the brake pedal and switches the automatic transmission 1 from the P range to the D range. After that, as long as the brake pedal is depressed, idling up is continued. Therefore, the activation time of the catalyst device can be shortened to enhance the catalyst activation promoting effect.

  In addition, when the vehicle stops after it has traveled, for example, when the vehicle starts to stop from the parking lot, or when the vehicle stops temporarily when waiting for a signal or going on a public road, an idle-up request is made with the D range already selected. In some cases, neutral idle control is performed in which the first clutch 40 of the speed change mechanism 5 is slipped.

  By the way, conventionally, the idle up is performed after the first clutch 40 shifts to the slip state. However, since this control is performed over time especially at the cold start, the start of the idle up is started. Was late.

  On the other hand, in this embodiment, in the neutral idle control, since the second brake 70 is engaged in response to the idle up request (S42), even if the idle up is performed during the control of the first clutch 70 to the slip state, The vehicle will not start against the driver's willingness to brake. Therefore, the idle up can be started before the transition to the slip state is completed, and even in this case, the activation time of the catalyst device can be shortened and the catalyst activation promoting effect can be enhanced.

  At this time, the interlock state is determined when the hydraulic pressure supplied to the second brake 70 reaches the interlock determination pressure (S44), and the slip state is determined when the input shaft speed reaches the target slip speed. Is done. Therefore, the idle up can be started earlier than the prior art by the time indicated by the symbol T in FIG.

  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, in the vehicle powertrain system control method and powertrain system in which the fluid transmission device is disposed between the engine and the speed change mechanism, the catalyst device is provided in the exhaust passage of the engine. When it is installed, it is possible to perform idle-up control in the traveling range at an early stage without causing deterioration of start response or unintentional start in order to promote activation of the catalyst device during cold start. Therefore, it may be suitably used in the field of manufacturing this type of vehicle.

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

Claims (4)

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. catalytic device is disposed above,
An idle-up request determination step for determining whether or not there is an idle-up request for promoting activation of the catalyst device when there is a braking request for the vehicle by the driver in a stopped state in the travel range;
A neutral idle step for transitioning the starting friction element from the engaged state to the predetermined slip state when it is determined in the idle up request determining step that there is an idle up request;
Similarly, when it is determined that there is an idle-up request, an interlocking step for bringing the speed change mechanism into an interlock state by fastening a predetermined friction element other than the starting friction element in the speed change mechanism;
An interlock determination step of determining whether or not the speed change mechanism is in an interlock state;
An idle-up step of increasing the idle rotation speed and maintaining the rotation speed when it is determined in the interlock determination step that the transmission mechanism is in the interlock state compared to when the catalyst device is in the active state A method for controlling a powertrain system, comprising:   2. The power train system according to claim 1, wherein the interlock step is performed until the idle up step is completed even after the starting friction element is in a predetermined slip state by the neutral idle step. Control method. A vehicle powertrain system comprising an engine, a speed change mechanism including a plurality of friction elements, and an automatic transmission having a fluid transmission that transmits engine output to the speed change mechanism,
When a catalyst device is disposed on the exhaust path of the engine,
When there is a braking request for the vehicle by the driver in a stopped state in the travel range, it is determined whether there is an idle up request for promoting activation of the catalyst device,
When it is determined that there is an idle up request, the starting friction element in the transmission mechanism is shifted from the engaged state to the predetermined slip state,
Similarly, when it is determined that there is an idle-up request, the transmission mechanism is interlocked by fastening a predetermined friction element other than the starting friction element in the transmission mechanism,
Determining whether the speed change mechanism is in an interlock state,
A power comprising: a controller that, when it is determined that the speed change mechanism is in an interlock state , increases the idle speed and maintains the speed as compared with when the catalyst device is in an active state. Train system. The predetermined friction element is a hydraulic clutch,
The interlock determination step determines that the transmission mechanism is in an interlock state when the hydraulic pressure supplied to the predetermined friction element reaches a predetermined hydraulic pressure. The powertrain system control method described.

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