JP2012218670A - Controller of driving device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a driving device for a vehicle, for improving speed change responsiveness and reducing speed change shock by engagement control of a lock-up clutch provided in a torque converter.SOLUTION: When performing downshift by grip change of engagement elements in an automatic transmission 16 during coast travel, a lock-up clutch 26 is engaged in synchronism with disengagement of a disengaging side engagement elements, and blipping control of temporarily raising a rotation speed Nof an engine 12 by an electronic throttle valve 22 is performed in the state of engaging the lock-up clutch 26. Thus, dispersion of controllability of the engine rotation speed Nis suppressed by performing the blipping control after the lock-up clutch 26 is engaged, and the input rotation speed of the torque converter 14 is highly accurately controlled.

Description

  The present invention relates to a control device for a vehicle drive device including a lockup clutch in a torque converter, and more particularly to an improvement for realizing an improvement in shift response and a reduction in shift shock.

  There is known a vehicle drive device that includes a torque converter provided between an engine and an automatic transmission, and a lock-up clutch that directly connects an input rotary member and an output rotary member of the torque converter by engagement. Yes. Further, a technique has been proposed for improving the shift response by controlling the engagement state of the lockup clutch when the automatic transmission is downshifted in such a vehicle drive device. For example, the control device of the driving device described in Patent Document 1 is this. According to this technique, the responsiveness of the downshift can be improved by engaging the lockup clutch at the time of downshifting of the automatic transmission and increasing the engine rotation speed by the power of the motor generator. .

Japanese Patent Laid-Open No. 2000-179677

  By the way, the said vehicle drive device is equipped with the electronic throttle valve which controls the output rotational speed of the said engine based on an electrical command. In addition, a blipping control is known in which, when a downshift is performed in the automatic transmission during coasting, the output rotation speed of the engine is temporarily increased by the electronic throttle valve. When the inventor considers using both the blipping control and the engagement control of the lockup clutch according to the prior art when downshifting the automatic transmission, the engagement state of the lockup clutch is considered. A new problem has been found that the controllability may vary due to the difference. Based on such knowledge, the inventors have invented a control device for a vehicle drive device that realizes improvement of shift response and reduction of shift shock by controlling engagement of a lock-up clutch provided in the torque converter.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to realize an improvement in shift response and a reduction in shift shock by engagement control of a lock-up clutch provided in the torque converter. Another object of the present invention is to provide a control device for a vehicle drive device.

  In order to achieve such an object, the gist of the first invention is an engine and an automatic transmission that selectively establishes a plurality of shift stages by a combination of engagement and release of a plurality of engagement elements. A torque converter provided between the engine and the automatic transmission; a lockup clutch that directly connects an input rotating member and an output rotating member of the torque converter by engagement; and the engine based on an electrical command. An electronic throttle valve that controls the output rotational speed of the vehicle drive device, and when downshifting by re-engaging the engaging element in the automatic transmission during coasting is performed, The engine is engaged in a state in which the lock-up clutch is engaged in synchronization with the release of the disengagement-side engagement element, and the lock-up clutch is engaged. It is characterized in carrying out the temporarily blipping controlled to increase the output rotational speed by the electronic throttle valve.

  As described above, according to the first aspect of the present invention, when a downshift is performed by re-holding the engagement element in the automatic transmission during coasting, the lockup is performed in synchronization with the release of the release-side engagement element. Since the clutch is engaged and blipping control is performed to temporarily increase the output rotational speed of the engine by the electronic throttle valve in a state in which the lockup clutch is engaged, By performing blipping control after engagement, it is possible to suppress variations in the controllability of the engine rotation speed and to control the input rotation speed of the lockup clutch with high accuracy. That is, it is possible to provide a control device for a vehicle drive device that realizes improvement of shift response and reduction of shift shock by controlling engagement of a lockup clutch provided in the torque converter.

  Here, the gist of the second invention subordinate to the first invention is that after the blipping control is performed and before the engagement side engaging element is engaged in the downshift, The lockup clutch is shifted to the slip engagement state. If it does in this way, the shock at the time of engagement of the engagement side engagement element in the said downshift can be suppressed, and the shift shock in the downshift can further be reduced.

It is a figure explaining the drive device for vehicles to which this invention is applied suitably, and its control system. FIG. 2 is a skeleton diagram illustrating a configuration of a torque converter and an automatic transmission provided in the vehicle drive device of FIG. 1. 3 is an engagement operation table that summarizes the relationship between a plurality of shift stages that are selectively established in the automatic transmission of FIG. 2 and the operation states of a plurality of hydraulic friction engagement devices. It is a functional block diagram explaining the principal part of the control function with which the electronic controller in the vehicle drive device of FIG. 1 was equipped. It is a time chart for demonstrating an example of the control action of the electronic controller in the vehicle drive device of FIG. 3 is a flowchart for explaining a main part of coast downshift control by an electronic control unit in the vehicle drive device of FIG. 1.

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

  FIG. 1 is a diagram for explaining a vehicle drive device 10 (hereinafter simply referred to as drive device 10) to which the present invention is preferably applied and a control system thereof. The drive device 10 shown in FIG. 1 includes an engine 12, which is a driving source for traveling, a torque converter 14, and an automatic transmission 16, which are provided in series. A power transmission device that is provided between the drive wheels and that sequentially transmits the power output from the engine 12 to the pair of drive wheels via a differential gear device or the like constituting another part of the drive device. is there.

The engine 12 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine that generates driving force by combustion of fuel injected in a cylinder. The intake pipe 18 of the engine 12 is opened and closed by a throttle actuator 20 that operates based on an electrical signal (electrical command) from an electronic control unit 50 described later, thereby reducing the intake air amount of the engine 12. includes an electronic throttle valve 22 that can change the output rotational speed, ie, the engine rotational speed N _E of the engine 12 adjusted to. The engine output (output rotational speed) increases as the opening of the electronic throttle valve 22, that is, the throttle opening _θTH increases. Basically, based on an accelerator opening A _CC that is an operation amount of an accelerator pedal (not shown) based on a predetermined relationship, control is performed so that the throttle opening θ _TH increases as the accelerator opening A _CC increases. Is done. Further, in the driving device 10 of the present embodiment, control such that the throttle opening degree θ _TH is changed based on an electric signal output from the electronic control device 50 regardless of the accelerator operation, as in the blipping control described later. Executed.

  The torque converter 14 is a fluid power transmission device that transmits power via a fluid. The automatic transmission 16 is a stepped transmission in which any of a plurality of predetermined shift speeds (sixth speed in this embodiment) is selectively established. FIG. 2 is a skeleton diagram illustrating the configuration of the torque converter 14 and the automatic transmission 16. The torque converter 14 and the automatic transmission 16 are substantially symmetrical with respect to the axis C, and the lower half of the axis C is omitted in FIG.

  As shown in FIG. 2, the torque converter 14 is provided in a power transmission path between the engine 12 and the automatic transmission 16. The torque converter 14 includes a pump impeller (input rotating member) 14p connected to the crankshaft of the engine 12 and a turbine impeller (output rotating member) connected to the automatic transmission 16 via a turbine shaft 24. 14t and a stator impeller 14s that is prevented from rotating in one direction by a one-way clutch, and transmits power through the fluid between the pump impeller 14p and the turbine impeller 14t. is there. Between the pump impeller 14p and the turbine impeller 14t, there is provided a lockup clutch 26 that can directly connect between the pump impeller 14p and the turbine impeller 14t. The pump impeller 14p has a hydraulic pressure that serves as a source pressure for controlling the shift of the automatic transmission 16, controlling the operation of the lock-up clutch 26, or supplying lubricating oil to each part. Is coupled to a mechanical oil pump 30 that is driven to rotate by the pump impeller 14p.

The lockup clutch 26 is controlled by the hydraulic pressure supplied from the hydraulic control circuit 28 so that the differential pressure between the hydraulic pressure in the engagement side oil chamber 32 and the hydraulic pressure in the release side oil chamber 34 is controlled. This is a hydraulic friction clutch that is frictionally engaged with each other. The operating state of the torque converter 14 is, for example, a so-called lock-up released state (non-engaged state) in which the differential pressure is negative and the lock-up clutch 26 is released, and the differential pressure is zero or more. A so-called lock-up slip state (half-engaged state) in which the lock-up clutch 26 is half-engaged with slip, and a so-called lock in which the differential pressure is maximized and the lock-up clutch 26 is completely engaged. It is roughly divided into three states, that is, an up state (engaged state). For example, when the lockup clutch 26 is completely engaged, the pump impeller 14p and the turbine impeller 14t are integrally rotated, and the power of the engine 12 is directly transmitted to the automatic transmission 16 side. Further, the differential pressure is controlled to engage at a predetermined slip state, for example, the slip amount N _S (absolute value of the difference between the engine rotational speed N _E and the turbine rotational speed N _T) is feedback-controlled Accordingly, while the power-on running of the vehicle above the turbine shaft 24 by a predetermined slip amount N _S is caused to follow the rotation relative to the crankshaft, the crankshaft of the engine 12 at a predetermined slip amount N _S at power-off of the vehicle Is rotated following the turbine shaft 24. Target value or target slip amount N _S of the slip amount N _S is preset to, for example, about 50 to 100 [rpm].

  The automatic transmission 16 is preferably used by being mounted horizontally in an FF (front engine / front drive) vehicle, and a single pinion is provided in a transmission case 38 as a non-rotating member attached to the vehicle body. A first planetary gear device 40 of a type and a Ravigneaux type planetary gear device 46 comprising a second planetary gear device 42 of double pinion type and a third planetary gear device 44 of single pinion type are provided on a common axis C. Then, the rotation of the turbine shaft 24 is shifted through each planetary gear device and output from the output gear 48. The turbine shaft 24 corresponds to an input member of the automatic transmission 16. The output gear 48 corresponds to an output member of the automatic transmission 16, and its differential gear is used to transmit power to a differential gear device (not shown) provided on the rear stage side of the automatic transmission 16. It functions as a differential drive gear that meshes with the differential driven gear of the gear unit.

  The automatic transmission 16 is in an engaged state between the respective rotating elements (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) or an engaged state between the rotating elements and the transmission case 38. Accordingly, a plurality of engagement elements for selectively establishing one of the six forward shift stages from the first shift stage “1st” to the sixth shift stage “6th” and one reverse shift stage “Rev”. As shown in FIG. 2, clutches C1 and C2 and brakes B1 to B3 are provided. These clutches and brakes are, for example, hydraulic frictional engagement devices controlled by hydraulic actuators such as multi-plate clutches and brakes, and the electromagnetic control valve provided in the hydraulic control circuit 28 is excited. Is controlled, the engagement state is switched and the excessive hydraulic pressure at the time of engagement and release is controlled.

  FIG. 3 is an engagement operation table that summarizes the relationship between the plurality of shift stages that are selectively established in the automatic transmission 16 and the operation states of the clutches and brakes. As shown in FIG. 3, in the automatic transmission 16, the first shift stage "1st" is established by the engagement of the clutch C1 and the brake B2. Further, the second shift stage “2nd” is established by engagement of the clutch C1 and the brake B1. Further, the third shift stage “3rd” is established by engagement of the clutch C1 and the brake B3. Further, the fourth shift stage “4th” is established by engagement of the clutch C1 and the clutch C2. Further, the fifth shift speed “5th” is established by engagement of the clutch C2 and the brake B3. Further, the sixth shift stage “6th” is established by engagement of the clutch C2 and the brake B1. Further, the reverse shift stage “Rev” is established by the engagement of the brake B2 and the brake B3. Further, the neutral “N” is established by releasing all the engaging elements.

  In the automatic transmission 16, a so-called clutch-to-clutch shift is performed by changing the engagement element. For example, in the downshift from the fourth shift stage “4th” to the third shift stage “3rd” (shift from a shift stage having a small gear ratio to a large shift stage), the engagement of the clutch C1 is maintained, and The clutch C2 is switched to the brake B3, that is, the release-side engagement element (the engagement element released before the shift) is the release control of the clutch C2 and the engagement-side engagement element (the engagement element engaged after the shift) ), The engagement control of the brake B3 is sequentially performed. Further, as shown in FIG. 3, at the forward shift stage in the automatic transmission 16, a so-called clutch-to-clutch shift is performed by re-engaging the engaging element in all downshifts.

  Returning to FIG. 1, the drive device 10 is an electronic control device 50 for performing various controls such as output control of the engine 12, shift control of the automatic transmission 16, and engagement control of the lockup clutch 26. It has. The electronic control device 50 corresponds to a control device for a vehicle drive device according to the present invention, and includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The various controls are performed by performing signal processing according to a program stored in the ROM in advance while using the temporary storage function.

As shown in FIG. 1, the electronic control device 50 is input with signals from various sensors that are provided in each part of the vehicle and indicate the state of the vehicle. For example, a signal indicating the throttle opening θ _TH of the electronic throttle valve 22 detected by the throttle opening sensor 52 and an accelerator opening A _CC which is an operation amount of an accelerator pedal (not shown) detected by the accelerator opening sensor 54 are obtained. representing signal, an engine signal indicative of engine rotational speed N _E of the rotational speed the engine 12 detected by the sensor 56, a signal representative of the turbine speed N _T of the detected by a turbine rotational speed sensor 58 the turbine wheel 14t, the vehicle speed signal representing the vehicle speed V detected by the sensor 60, and a signal or the like representing the operation position P _SH of the shift lever 64 detected by a lever position sensor 62, are supplied.

Further, the electronic control device 50 outputs a signal for controlling the operation of various devices provided in the driving device 10. For example, the engine output control command signal S _E for controlling the output of the engine 12 is injected from a throttle signal for driving the throttle actuator 20 for controlling the opening and closing of the electronic throttle valve 22 and from a fuel injection device (not shown). An injection signal for controlling the amount of fuel and an ignition timing signal for controlling the ignition timing of the engine 12 by an ignition device (not shown) are output. Further, examples of the shift control command signal S _TM for shift control of the automatic transmission 16, for driving the hydraulic control circuit various solenoid valves (not shown) each of the plurality of engaging elements provided in correspondence with the 28 Are output. Further, as a lock-up clutch engagement control signal S _LU for engagement control of the lock-up clutch 26, the hydraulic control circuit 28 in the signal for driving the lockup control linear solenoid valve SLU provided in such Is output.

  The shift lever 64 is disposed, for example, in the vicinity of the driver's seat and is manually operated to five operation positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It has come to be. The operation position “P” is a parking position for mechanically preventing the output gear 48 of the automatic transmission 16 from rotating by a mechanical parking mechanism. The operation position “R” is a reverse travel position for establishing the reverse shift stage “Rev” in the automatic transmission 16. The operation position “N” is a neutral position for establishing a neutral state in which power transmission in the automatic transmission 12 is interrupted. In addition, the operation position “D” is set to any one of the first shift speed “1st” to the sixth shift speed “6th” based on the traveling state of the vehicle. This is a forward travel position for selecting an automatic shift mode in which automatic shift control for switching to 1 is executed. The operation position “S” is for switching the shift speed of the automatic transmission 12 to the high speed side and the low speed side every time the shift lever 64 is operated to the operation positions “+” and “−”. This is a forward travel position for selecting a manual shift mode in which manual shift control is executed.

FIG. 4 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 50. The shift control means 68 shown in FIG. 4 performs automatic shift control of the automatic transmission 16 based on the running state (driving state) of the vehicle from a previously stored relationship. For example, from a predetermined automatic shift map, based on the accelerator opening A _CC (or the throttle valve opening θ _TH ) detected by the accelerator opening sensor 52 and the vehicle speed V detected by the vehicle speed sensor 60, The shift stage to be established in the automatic transmission 16 is determined, and the engagement state of each of the plurality of engagement elements provided in the automatic transmission 16 is controlled so that the determined shift stage is established. . Specifically, as the shift control command signal _STM , electrical signals (electrical commands for driving various solenoid valves (not shown) provided corresponding to the plurality of engagement elements in the hydraulic control circuit 28). ) Is output.

  In order to realize the shift control, the shift control means 68 includes an opening side engagement element control means 70, an engagement side engagement element control means 72, and a shift progress degree determination means 74. When the shift control by the shift control unit 68 is performed, the disengagement-side engagement element control unit 70 performs control to open the disengagement-side engagement element that is released during the shift (before the shift). For example, in the clutch-to-clutch shift, an electric signal for releasing an engagement element to be released is output to a corresponding electromagnetic valve provided in the hydraulic pressure control circuit 28. The release of the release side engagement element is preferably started substantially simultaneously with the shift determination by the shift control means 68. Further, when the shift control by the shift control unit 68 is performed, the engagement side engagement element control means 72 performs control to engage the engagement side engagement elements that are engaged in the shift (after the shift). For example, in the clutch-to-clutch shift, an electric signal for engaging an engagement element to be engaged is output to a corresponding electromagnetic valve provided in the hydraulic pressure control circuit 28. The engagement of the engagement side engagement element is preferably performed at the stage where the release of the release side engagement element has progressed to some extent (or after it has been completely released). For example, the engagement control of the engagement side engagement element is started after a predetermined time after the shift determination by the shift control means 68.

Further, the shift progress determination unit 74 determines whether or not the shift control progress by the shift control unit 68 exceeds a predetermined threshold. For example, whether or not the disengagement state of the disengagement-side engagement element in the clutch-to-clutch shift by the shift control means 68 has reached a prescribed stage, that is, the engagement pressure of the disengagement-side engagement element is a predetermined threshold value. It is determined whether or not it is less than. Further, whether or not the engagement state of the engagement side engagement element in the clutch-to-clutch shift by the shift control means 68 has reached a predetermined stage, that is, the engagement pressure of the engagement side engagement element is determined in advance. It is determined whether or not the threshold value is exceeded. These determinations may be made based on the detection results of the hydraulic sensors provided corresponding to the disengagement side engagement element and the engagement side engagement element, respectively. From the start of the shift control by the shift control means 68 to the time until the release of the release-side engagement element and the time to complete the engagement of the engagement-side engagement element are measured and stored. The elapsed time may be measured, and it may be determined whether the elapsed time is equal to or greater than a predetermined threshold. Further, there is performed the determination of the shift progress degree based on the change of the turbine rotational speed N _T or the like which is detected by the engine rotational speed N _E and the turbine rotational speed sensor 58 detected by the engine rotational speed sensor 56 Also good. For example, in the downshift by the shift control means 68, it said that the engine rotational speed N _E to the turbine rotational speed N _T is determined whether a predetermined threshold or more, determines the shift progress degree be able to.

The lock-up control means 76 controls the engagement of the lock-up clutch 26 based on the traveling state (driving state) of the vehicle from the relationship stored in advance. For example, the storage device provided in the electronic control unit 50 includes a torque converter region in which the lockup clutch 26 is opened based on the throttle valve opening θ _TH or the accelerator opening A _CC and the vehicle speed V, and the lockup clutch A lock-up clutch engagement map in which a lock-up slip region for half-engaging (slip engagement) 26 and a lock-up region for engaging (completely engaging) the lock-up clutch 26 are respectively stored in advance. The lockup control means 76 has a throttle valve opening θ _TH detected by the throttle opening sensor 52 and an accelerator opening A detected by the accelerator opening sensor 54 from the lockup clutch engagement map. _CC, and based on the vehicle speed V or the like which is detected by the vehicle speed sensor 60, the lockup The hydraulic control circuit 28 determines whether to perform the release control for releasing the clutch 26, the lock-up slip control for half-engagement, or the lock-up control for full engagement, and performs the determined control. An electrical signal is output to the lockup control linear solenoid valve SLU.

Blipping control means 78, when the shift control by the shift control means 68, when a predetermined condition is satisfied, by the rotational speed N _E of the engine 12 for the purpose of transmission time shortening electronic throttle valve 22 The blipping control to raise temporarily is executed. For example, when the gearshift control means 68 performs a coast downshift (power-off downshift), that is, when a downshift is performed when the accelerator opening degree A _CC detected by the accelerator opening degree sensor 54 is zero (accelerator off). from experimentally determined in advance was relationship, the absolute value is output rotational speed of the difference between the output rotational speed and the difference or the turbine speed N _T and the engine rotational speed N _E and the input rotational speed of the torque converter 14 difference △ based on N, determines whether the temporary engine speed N _E to have blipping required to increase. Specifically, when the input / output rotational speed difference ΔN is equal to or larger than a predetermined input / output rotational speed difference ΔN1, it is determined that there is a blipping request.

If it is determined that there is blipping required in the determination, the blipping control unit 78, upon coast downshift executed by the shift control means 68, temporarily engine rotational speed N _E by the electronic throttle valve 22 Blipping control is performed. Specifically, during a predetermined time after it is determined that the automatic transmission 16 is in a neutral state during the coast downshift in the shift control means 68, the throttle opening _θTH is increased by a predetermined specified value. Let The specified value and the predetermined time are experimentally obtained and stored in advance so that the input / output rotational speed difference ΔN becomes smaller than a predetermined value A during the coast downshift, for example. The predetermined value A, also perform lock-up control or lock-up slip control, for example, it is difficult to raise the engine speed N _E by the torque capacity shortage of the lock-up clutch 26, the engine rotational speed large shock occurs in association with the pulling of the N _E, or as a value calorific no problems such as exceeding the allowable value is generated in the lock-up clutch 26, a value obtained experimentally in advance.

  In the present embodiment, the lock-up control means 76 is released when a coast downshift (clutch-to-clutch shift) is performed by the shift control means 68 by re-holding the engagement element in the automatic transmission 16. Control for engaging the lockup clutch 26 is performed in synchronization with the release of the side engagement element. That is, as shown in FIG. 5, when a downshift from the fourth speed “4th” to the third speed “3rd” during coasting is determined (requested) at time t1, the time t1 When the engagement state of the lock-up clutch 26 is a lock-up released state or a lock-up slip state, the lock-up clutch 26 is started to be engaged and the lock-up state (fully engaged state) is established. Execute up control. Preferably, as shown in FIG. 5, when it is determined that the disengagement side engagement element (clutch C2 in the case of a downshift from the fourth speed “4th” to the third speed “3rd”) is released. That is, the lockup control for completely engaging the lockup clutch 26 is executed at the time t2 when it is determined by the shift progress determination means 74 that the release state of the release-side engagement element has reached the specified stage. In other words, in a coast downshift by re-engaging the engagement element, the release-side engagement element is released and the neutral state is established, and then the lock-up clutch 26 is engaged to shift to the lock-up state. The shock when the lockup clutch 26 is engaged (when the lockup is shifted) can be reduced.

Further, the blipping control means 78 is in a state in which the lockup clutch 26 is engaged when the shift control means 68 performs a coast downshift by gripping the engagement element in the automatic transmission 16. The blipping control is executed. That is, it is determined that the disengagement state of the disengagement side engagement element in the coast downshift has reached a specified stage by the shift progress determination means 74, and the lockup clutch 26 is completely engaged by the lockup control means 76. After the lockup control is executed, the blipping control is executed to increase the throttle opening θ _TH of the electronic throttle valve 22 through the throttle actuator 20 by a predetermined value set for a predetermined time. In the example shown in FIG. 5, after the lock-up control for engaging the lock-up clutch 26 is executed at time t2, a request (output) for the blipping control is made after a predetermined time has passed. Further, the engine rotation speed _NE and the turbine rotation speed _NT are increased in accordance with the blipping control, and the input / output rotation speed difference ΔN is reduced. 26 engagements are possible.

The lockup control means 76 performs blipping control by the blipping control means 78 when the shift control means 68 performs a coast downshift by gripping the engaging element in the automatic transmission 16. After the engagement, the engagement side engaging element in the coast downshift (the brake B3 in the downshift from the fourth speed “4th” to the third speed “3rd”) is engaged before the engagement. The up clutch 26 is shifted to the slip engagement state (half engagement state). For example, the step of the possible shift progress determining unit 74 by the engine rotational speed N _E to the turbine rotational speed N _T becomes a predetermined threshold or more is determined, or provisions predetermined time from the shift start When the time has elapsed, the lock-up slip control for slip-engaging the lock-up clutch 26 is started. In the example shown in FIG. 5, it is determined that the shift progress of the coast downshift has exceeded a predetermined threshold at time t3, and the lockup slip control is started accordingly. This time point t3 corresponds to a stage where the engagement side clutch pressure, that is, the engagement pressure of the engagement side engagement element has started to rise, but has not yet been engaged (completely engaged). Further, the engagement pressure for achieving the slip amount N _S ie the slip amount N _S of the lock-up clutch 26 in the lock-up slip control after the blipping control (differential pressure) is reduced after the blipping control start It is determined based on the difference between the output rotational speed of the torque converter 14 and the input rotational speed, that is, the input / output rotational speed difference ΔN.

  FIG. 6 is a flowchart for explaining a main part of the coast downshift control by the electronic control unit 50, and is repeatedly executed at a predetermined cycle.

First, in step (hereinafter, step is omitted) S1, coasting down in the automatic transmission 16 based on the accelerator opening A _CC (or throttle valve opening θ _TH ) and the vehicle speed V from a predetermined automatic shift map. It is determined whether or not a shift is determined. If the determination in S1 is negative, but with a routine which it is terminated, if the determination in S1 is affirmative, in S2, the difference between the turbine speed N _T and the engine rotational speed N _E It is determined whether or not there is a blipping control request based on the input / output rotational speed difference ΔN that is the absolute value of the above, that is, whether or not the coasting downshift is combined with the blipping control. If the determination in S2 is negative, the routine is terminated accordingly. However, if the determination in S2 is affirmative, in S3, release of the disengagement side engagement element in the coast downshift is started. It is determined whether or not. If the determination at S3 is negative, the process waits by repeating the determination at S3. If the determination at S3 is affirmative, the lockup clutch 26 is engaged (completely engaged) at S4. Lockup control is performed. Next, in S5, blipping control is executed to increase the throttle opening degree θ _TH of the electronic throttle valve 22 through the throttle actuator 20 by a predetermined value set for a predetermined time. Next, in S6, whether or not the shift downshift of the coast downshift has exceeded a predetermined threshold, for example, whether or not the engine rotational speed _NE or the turbine rotational speed _NT has reached or exceeded a predetermined threshold. To be judged. If the determination in S6 is negative, the determination is made to wait by repeating the determination in S6. However, if the determination in S6 is affirmative, the lock-up clutch 26 is slip-engaged (half-finished) in S7. After the lock-up slip control to be engaged is started, this routine is terminated. In the above control, S1, S3, and S6 correspond to the operation of the shift control means 68, S4 and S7 correspond to the operation of the lockup control means 76, and S5 corresponds to the operation of the blipping control means 78, respectively. .

As described above, according to this embodiment, when downshift is performed by re-holding the engagement element in the automatic transmission 16 during coasting, the lockup is performed in synchronization with the release of the release-side engagement element. since the clutch 26 is engaged, and performs temporary blipping control for increasing the rotational speed N _E of the engine 12 in a state where the lock-up clutch 26 is engaged by the electronic throttle valve 22, By performing blipping control after the lockup clutch 26 is engaged, it is possible to suppress variations in controllability of the engine rotational speed _NE , and to control the input rotational speed of the lockup clutch 26 with high accuracy. Is done. That is, it is possible to provide a control device for the vehicle drive device 10 that realizes an improvement in shift response and a reduction in shift shock by controlling the engagement of the lockup clutch 26 provided in the torque converter 14.

Compared with the control of the present embodiment, in the conventional control, when the lockup clutch 26 is released (lockup off state) for some reason during deceleration, switching from accelerator on to accelerator off is performed. Lock-up control could not be resumed until. If lockup control is not performed in spite of the driver requesting deceleration due to accelerator off, sufficient deceleration cannot be achieved, and drivability may be reduced. Further, if the lock-up control during deceleration is not performed, since the direction of the turbine rotation speed N _T than the input rotation speed of the torque converter 14 is greater than the turbine speed N _T during re-acceleration of the torque converter 14 Sufficient acceleration could not be obtained until the input rotational speed was increased, and drivability might be reduced. With respect to such a point, according to the present embodiment, the lockup clutch 26 is engaged in synchronization with the release of the disengagement-side engagement element in the coast downshift, and the lockup clutch 26 is engaged when the lockup clutch 26 is engaged. By performing the blipping control, it is possible to solve the above problems and improve the shift response and reduce the shift shock.

  Further, after the blipping control is performed, the lock-up clutch 26 is shifted to the slip engagement state before the engagement-side engagement element is engaged in the downshift. The shock at the time of engagement of the engagement-side engagement element in the shift (during the shift synchronization) can be suppressed, and the shift shock in the downshift can be further reduced.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Is.

  10: Vehicle drive device, 12: Engine, 14: Torque converter, 14p: Pump impeller (input rotating member), 14t: Turbine impeller (output rotating member), 16: Automatic transmission, 22: Electronic throttle valve, 26: lock-up clutch, 50: electronic control unit, C1, C2: clutch (engagement element), B1 to B3: brake (engagement element)

Claims (2)

An engine, an automatic transmission that selectively establishes a plurality of shift speeds by a combination of engagement and release of a plurality of engagement elements, a torque converter provided between the engine and the automatic transmission, A lockup clutch that directly connects the input rotary member and the output rotary member in the torque converter, and an electronic throttle valve that controls the output rotational speed of the engine based on an electrical command. A control device,
When a downshift is performed by re-holding the engagement element in the automatic transmission during coasting, the lockup clutch is engaged in synchronization with the release of the release-side engagement element, and the lockup clutch is engaged. A control device for a vehicle drive device, wherein blipping control is performed to temporarily increase the output rotation speed of the engine by the electronic throttle valve in the combined state.   2. The vehicle according to claim 1, wherein after the blipping control is performed, the lock-up clutch is shifted to a slip engagement state before engagement of an engagement-side engagement element in the downshift is performed. Drive device controller.

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