JP2018013231A - Control device of power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a power transmission device for a vehicle which suitably shortens a time for transiting from packing control to differential rotation control.SOLUTION: Takeover control starts boosting control for boosting a lockup engagement pressure Pof a lockup clutch 32 accompanied by a finish of constant pressure standby control being packing control, and when a state that a difference between an actual difference rotation ΔNand a target difference rotation ΔN* becomes a prescribed value A or lower continues for a preset first time ta1 or longer, or when the actual lockup engagement pressure Pof the lockup clutch 32 is higher than a stroke end pressure Pat which a pack clearance is packed by a prescribed pressure α or more and the state continues for a preset second time ta2 or longer after the start of the boosting control, the boosting control is finished and the difference rotation control is started.SELECTED DRAWING: Figure 7

Description

  The present invention controls the packing pressure of the lockup clutch so that the pack clearance of the lockup clutch is quickly packed, and the engagement pressure of the lockup clutch so that the actual differential rotation of the lockup clutch matches the preset target differential rotation. In a control device for a vehicle power transmission device that executes differential rotation control and takeover control for increasing the engagement pressure from the packing control and taking over the differential rotation control, the difference from the packing control to the difference The present invention relates to a technique for suitably shortening the time for shifting to rotation control.

  In a vehicle power transmission device including a fluid transmission device capable of directly connecting an input member and an output member by engagement of a lockup clutch, the lockup clutch is engaged so that the lockup clutch slips at a predetermined differential rotation. A flex lock-up control unit for controlling pressure, and the flex lock-up control unit performs pack packing control for quickly packing the pack clearance of the lock-up clutch; Of the vehicle power transmission device that executes differential rotation control for controlling the engagement pressure of the lockup clutch so that the differential rotations of the lockup clutches coincide with each other and takeover control for taking over from the pack control to the differential rotation control. Control devices are known. For example, the control device for a vehicle power transmission device described in Patent Document 1 is the same. In the above-mentioned Patent Document 1, the lockup clutch flex lockup control is calculated by adding the first correction amount to the base command pressure in the first control phase until the friction material of the lockup clutch comes into substantially contact. For example, by subtracting the second correction amount from the base command pressure in the second control phase, which is obtained in consideration of the actual differential rotation so that the differential rotation of the lockup clutch approaches the target differential rotation, When calculating and switching to the command pressure after pressure reduction correction, the difference between the first correction amount before the switching and the second correction amount after the switching decreases at a predetermined rate of change regardless of the change in the base command pressure. Thus, it is described that the command pressure at the time of switching transition when the command pressure after the pressure increase correction is switched to the command pressure after the pressure reduction correction is controlled according to the change in the base command pressure. . Further, in Patent Document 1, it is determined whether or not the switching transient command pressure has reached the post-reduction pressure command pressure that is a post-switching command pressure, and the switching transient command pressure is determined to be the post-decompression pressure command. Control is executed until the pressure becomes equal.

JP 2013-19428 A

  By the way, in the control device for a vehicle power transmission device such as the above-mentioned Patent Document 1, when shifting from the first control phase to the second control phase, that is, from the pack control for packing the pack clearance of the lockup clutch, When shifting to the differential rotation control for controlling the engagement pressure of the lockup clutch so that the actual differential rotation of the lockup clutch matches the preset target differential rotation, the command pressure during the switching transient is reduced. The control to carry over from the pack control to the differential rotation control is executed until the post-correction command pressure becomes equal, that is, until the engagement pressure of the lock-up clutch becomes equal to a predetermined pressure. The robustness of the clutch control is low, and it takes a long time to shift from the packing control to the differential rotation control. In this case, the fuel consumption caused racing of the engine there is a possibility that lowered by the engagement delay of the lock-up clutch.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a control device for a vehicle power transmission device that suitably shortens the time required for shifting from pack control to differential rotation control. There is to do.

  The subject matter of the first invention is (a) a vehicle power transmission device including a fluid transmission device capable of directly connecting an input member and an output member by engagement of a lock-up clutch. A flex lockup control unit that controls an engagement pressure of the lockup clutch so that the lockup clutch slips; and (c) the flex lockup control unit quickly packs a pack clearance of the lockup clutch. Packing control, differential rotation control for controlling the engagement pressure of the lockup clutch so that the actual differential rotation of the lockup clutch matches a preset target differential rotation, and completion of the packing control And (d) the takeover control to execute the takeover control to increase the engagement pressure and take over to the differential rotation control. The pressure increase control for increasing the engagement pressure of the lockup clutch is started with the end of the packing control, and (e) the state where the difference between the actual differential rotation and the target differential rotation is equal to or less than a predetermined value. When it continues for a preset first time or when the engagement pressure of the lock-up clutch is higher than a stroke end pressure by which the pack clearance is filled and a predetermined pressure is set from the start of the pressure increase control. When two hours or more have elapsed, the boost control is terminated and the differential rotation control is started.

  According to the first aspect of the present invention, the handover control starts a pressure increase control for increasing the engagement pressure of the lockup clutch upon completion of the pack packing control, and the difference between the actual differential rotation and the target differential rotation is started. Is maintained for a predetermined first time or more, or the engagement pressure of the lock-up clutch is higher than the stroke end pressure at which the pack clearance is packed and the pressure increase control When a preset second time or more has elapsed from the start of the above, the boost control is terminated and the differential rotation control is started. For this reason, if the state where the difference between the actual differential rotation and the target differential rotation is equal to or less than a predetermined value continues for a preset first time or more, the differential rotation suitable for starting the differential rotation control is performed. Since the actual differential rotation of the lockup clutch is approaching, the differential rotation control can be started. In addition, when the engagement pressure of the lockup clutch is higher than a predetermined pressure by the stroke end pressure at which the pack clearance is reduced and more than a preset second time has elapsed since the start of the pressure increase control, the lockup clutch Since it is considered that the engagement pressure of the clutch is higher than the stroke end pressure by a predetermined pressure or more and the pack clearance is surely packed, the differential rotation control can be started. As a result, the time required for shifting from the packing control to the differential rotation control can be suitably shortened as compared with, for example, the case where the handover control is executed until the engagement pressure of the lockup clutch becomes equal to a predetermined pressure. .

It is a figure explaining the schematic structure of the vehicle to which this invention is applied, and is a figure explaining the control function for various control in a vehicle. FIG. 2 is a skeleton diagram illustrating an example of a torque converter and an automatic transmission provided in the vehicle of FIG. 1. It is sectional drawing of the torque converter of FIG. 3 is an engagement operation table for explaining a relationship between a shift operation of the automatic transmission of FIG. 2 and a combination of operations of a hydraulic friction engagement device used therefor. FIG. 3 is a circuit diagram illustrating an example of a main part of a hydraulic control circuit related to a linear solenoid valve or the like that controls the operation of a lockup clutch provided in the torque converter of FIG. 2. 2 is a flowchart for explaining an example of a control operation of takeover control for taking over from constant pressure standby control to differential rotation control during flex lockup control in the electronic control device of FIG. 1. It is a time chart at the time of performing the control action shown to the flowchart of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for various controls in the vehicle 10. In FIG. 1, a vehicle 10 includes an engine 12, drive wheels 14, a vehicle power transmission device 16 (hereinafter referred to as a power transmission device 16) provided in a power transmission path between the engine 12 and the drive wheels 14. It has. The power transmission device 16 includes a torque converter (fluid transmission device) 20 and an automatic transmission 22 disposed in a case 18 (see FIG. 2) as a non-rotating member attached to the vehicle body, and output rotation of the automatic transmission 22. A transmission output gear 24, which is a member, includes a differential gear device (differential gear) 26 connected to a ring gear 26a, a pair of axles 28 connected to the differential gear device 26, and the like. In the power transmission device 16, the power output from the engine 12 is transmitted to the drive wheels 14 via the torque converter 20, the automatic transmission 22, the differential gear device 26, the axle 28 and the like in order.

  The engine 12 is a power source of the vehicle 10 and is, for example, an internal combustion engine such as a gasoline engine or a diesel engine.

  FIG. 2 is a skeleton diagram illustrating an example of the torque converter 20 and the automatic transmission 22. The torque converter 20, the automatic transmission 22, and the like are configured substantially symmetrically with respect to the axis RC of the transmission input shaft 30 that is an input rotation member of the automatic transmission 22, and in FIG. The lower half of RC is omitted.

As shown in FIGS. 2 and 3, the torque converter 20 includes a front cover 34 and a rear cover 35 welded to each other, and a plurality of pump blades 20 f fixed to the inside of the rear cover 35. A pump impeller (input member) 20p, which is connected to the shaft 12a so as to be able to transmit power and is arranged so as to rotate about the axis RC, and the rear cover 35, is connected to the transmission input shaft 30 so as to be able to transmit power. And a turbine impeller (output member) 20t. The torque converter 20 includes a lockup clutch 32 between that can be connected directly to the pump impeller 20p and the turbine impeller 20t by the lock-up engagement pressure P _SLU is supplied to the control oil chamber 20d to be described later . In this manner, the torque converter 20 functions as a vehicle fluid transmission device with a lock-up clutch 32 provided in a power transmission path between the engine 12 and the automatic transmission 22. The power transmission device 16 is provided with a mechanical oil pump 33 connected to the pump impeller 20p so as to be able to transmit power. The oil pump 33 is rotationally driven by the engine 12 to control the shift of the automatic transmission 22, engage the lockup clutch 32, and supply lubricating oil to each part of the power transmission path of the power transmission device 16. Generate hydraulic pressure to discharge (discharge).

  The lock-up clutch 32 is a hydraulic multi-plate friction clutch (wet multi-plate clutch). As shown in FIG. 3, the lock-up clutch 32 has a front cover 34 integrally connected to the pump impeller 20p. The first annular member 36 fixed by welding to the outer peripheral spline teeth 36a formed on the outer periphery of the first annular member 36 are engaged with each other so as not to rotate relative to the axis RC and to move in the direction of the axis RC. A plurality of (three in this embodiment) annular first friction plates 38 and a damper device 40 provided in the torque converter 20 are connected to the transmission input shaft 30 and the turbine impeller 20t so as to be able to transmit power. The second annular member 42 and the inner peripheral spline teeth 42a formed on the inner periphery of the second annular member 42 are engaged with each other so as not to rotate relative to the axis RC and to move in the direction of the axis RC. A plurality of (two in this embodiment) annular second friction plates 44 disposed between the plurality of first friction plates 38 and the inner peripheral portion 34a of the front cover 34 are fixed to the transmission input shaft. An annular pressing member (piston) 48 that is supported by a hub member 46 that supports the end portion of the front cover 34 on the front cover 34 so as to be rotatable about the axis RC and that is movable in the direction of the axis RC. An annular fixing member 50 that is supported by the hub member 46 at a fixed position and is disposed on the opposite side of the pressing member 48 from the front cover 34 side so as to face the pressing member 48; A return spring 52 that urges the fixing member 50 in the RC direction, that is, urges the pressing member 48 away from the first friction plate 38 and the second friction plate 44 in the axial center RC direction. .

As shown in FIG. 3, the torque converter 20 is provided in the front cover 34 and the rear cover 35, and is supplied from the hydraulic oil supply port 20a and the hydraulic oil supply port 20a to which the hydraulic oil output from the oil pump 33 is supplied. A main oil chamber (torque converter oil chamber) 20c having a hydraulic oil outlet port 20b through which the hydraulic fluid flows out is formed. Further, the lock-up clutch 32 and the first friction material 38 and the second friction material 44 of the lock-up clutch 32 for pressing the lock-up clutch 32 are pressed into the main oil chamber 20c of the torque converter 20. a control oil chamber 20d, for example lock-up engagement pressure P _SLU for biasing the pressing member 48 to the front cover 34 side is supplied, i.e. the front cover 34 side pressing member 48 for disengaging the lock-up clutch 32 For example, a front-side oil chamber 20e to which a second line oil pressure Psec, which will be described later for urging to the opposite side, is supplied, and the front-side oil chamber 20e communicates with the hydraulic oil from the front-side oil chamber 20e. A rear-side oil chamber 20g through which the hydraulic oil flows out from the hydraulic oil outlet port 20b is provided. The control oil chamber 20d is an oil-tight space formed between the pressing member 48 and the fixing member 50, and the front-side oil chamber 20e is formed between the pressing member 48 and the front cover 34. The rear oil chamber 20g is a space in the main oil chamber 20c excluding the control oil chamber 20d and the front oil chamber 20e.

In the torque converter 20, as shown in FIG. 3, for example, the hydraulic pressure supplied to the control oil chamber 20d, that is, the lock-up on-pressure P _LUPON (kPa) is relatively large (the hydraulic pressure in the front-side oil chamber 20e, that is, the torque converter in-pressure). When P _TCin (kPa) is relatively small), the pressing member 48 is urged and moved to the front cover 34 side as indicated by the alternate long and _short dash line, so that the pressing member 48 causes the first friction plate 38 and the second friction plate 38 to move. The pump impeller 20p connected to the first annular member 36 by pressing the plate 44 and the turbine impeller 20t connected to the second annular member 42 rotate integrally. That is, in the torque converter 20, when the lockup clutch 32 is engaged, the pump impeller 20p and the turbine impeller 20t are directly connected. Further, for example, when the lock-up on pressure P _LupON (kPa) in the control oil chamber 20d is relatively small (the torque converter in pressure P _TCin (kPa) in the front oil chamber 20e is relatively large), the pressing member 48 is When moved to a position away from the first friction plate 38 as indicated by a solid line, the pump impeller 20p connected to the first annular member 36 and the turbine impeller 20t connected to the second annular member 42 are relatively Rotate. That is, in the torque converter 20, when the lockup clutch 32 is released, the pump impeller 20p and the turbine impeller 20t are released.

The lockup clutch 32 includes a lockup on pressure P _LUPON (kPa) in the control oil chamber 20d, a torque converter in pressure P _TCin (kPa) in the front oil chamber 20e, and a torque output from the hydraulic oil outflow port 20b. Based on the differential pressure from the average value ((P _TCin + P _TCout ) / 2) of the converter out pressure P _TCout (kPa), that is, the lockup differential pressure ΔP (= P _LupON − (P _TCin + P _TCout ) / 2) Torque is controlled. Note that the above-described _{equation of} lockup differential pressure (engagement pressure) ΔP = P _LUPON− (P _TCin + P _TCout ) / 2 is an empirical formula determined in advance through experiments or the like. In the above formula, the torque converter in pressure P _TCin and the torque converter out pressure P _TCout are the engine speed Ne (rpm), the turbine speed Nt (rpm), and their differential speed (engine speed-turbine speed). It varies depending on ΔN (rpm), second line oil pressure Psec (kPa), ATF oil temperature Toil (° C.), engine torque Te (Nm), and the like. The torque converter out pressure P _TCout is changed by changing the centrifugal oil pressure in the rear oil chamber 20g of the torque converter 20 by changing the engine speed Ne, the turbine speed Nt, the ATF oil temperature Toil, and the like. To do.

  The lockup clutch 32 is controlled by the electronic control device (control device) 56 via the hydraulic control circuit (hydraulic circuit) 54 so that, for example, the lockup differential pressure ΔP is negative. A so-called lock-up released state (lock-up off) in which the lock-up clutch 32 is released, and a so-called lock-up slip state in which the lock-up differential pressure ΔP is set to zero or more and the lock-up clutch 32 is half-engaged with slip. (Slip state) and a so-called lock-up state (lock-up on) in which the lock-up differential pressure ΔP is set to the maximum value and the lock-up clutch 32 is completely engaged is switched to an operating state. In the torque converter 20, even if the lockup clutch 32 is in the lockup state, the lockup slip state, and the lockup release state, the front side oil chamber 20e and the rear side oil chamber 20g are in the same chamber, that is, the front side oil chamber 20e. And the rear side oil chamber 20g are always in communication with each other, and the lockup clutch 32 is always cooled by the hydraulic oil from the hydraulic oil supply port 20a toward the rear side oil chamber 20g.

  The automatic transmission 22 constitutes a part of a power transmission path from the engine 12 to the drive wheel 14 and includes a plurality of hydraulic friction engagement devices (first clutch C1 to fourth clutch C4, first brake B1, second brake). A planet that functions as a stepped automatic transmission in which a plurality of gear stages (gear stages) having different gear ratios (gear ratios) are formed by selectively engaging or releasing the brake B2) and the one-way clutch F1. This is a gear type multi-stage transmission. For example, it is a stepped transmission that performs a so-called clutch-to-clutch shift often used in vehicles. The automatic transmission 22 includes a double pinion type first planetary gear unit 58, a single pinion type second planetary gear unit 60 and a double pinion type third planetary gear unit 62 configured in Ravigneaux type on a coaxial line. (On the shaft center RC), the rotation of the transmission input shaft 30 is shifted and output from the transmission output gear 24.

  The first planetary gear unit 58 includes a first sun gear S1 that is an external gear, a first ring gear R1 that is an internal gear disposed concentrically with the first sun gear S1, a first sun gear S1, and a first ring gear R1. And a first carrier CA1 that supports the first pinion gear P1 so as to be able to rotate and revolve.

  The second planetary gear device 60 includes a second sun gear S2 that is an external gear, a second ring gear R2 that is an internal gear arranged concentrically with the second sun gear S2, a second sun gear S2, and a second ring gear R2. And a second carrier CA2 that supports the second pinion gear P2 so as to be capable of rotating and revolving.

  The third planetary gear unit 62 includes a third sun gear S3 that is an external gear, a third ring gear R3 that is an internal gear disposed concentrically with the third sun gear S3, and the third sun gear S3 and the third ring gear. It has a third pinion gear P3 made up of a pair of gears that meshes with R3, and a third carrier CA3 that supports the third pinion gear P3 so that it can rotate and revolve.

  By controlling the engagement and disengagement of these hydraulic friction engagement devices, as shown in the engagement operation table of FIG. 4, the forward 8 stages and the reverse 1 are made according to the accelerator operation of the driver, the vehicle speed V, and the like. Each gear stage is formed. In FIG. 4, “1st” to “8th” means the first shift speed to the eighth shift speed as the forward gear, and “Rev” means the reverse speed as the reverse gear. The gear ratio γ (= transmission input shaft rotational speed Nin / transmission output gear rotational speed Nout) of the automatic transmission 22 corresponding to the stage is determined by the first planetary gear unit 58, the second planetary gear unit 60, and the third planetary unit. Each gear ratio of the gear device 62 (= the number of teeth of the sun gear / the number of teeth of the ring gear) is appropriately determined.

As shown in FIG. 5, the hydraulic control circuit 54 includes a first line regulated by a lock-up control valve 64 and a relief-type first line pressure regulating valve 67 using the hydraulic pressure generated from the oil pump 33 as a source pressure. A linear solenoid valve _SLU that regulates the hydraulic pressure PL to the lock-up engagement pressure P _SLU and a modulator valve 66 that regulates the modulator hydraulic pressure P _MOD to a constant value using the first line hydraulic pressure PL as a source pressure are provided. The hydraulic control circuit 54 includes linear solenoid valves SL1 to SL6 (see FIG. 1) that control the operation of each hydraulic actuator (not shown) of the hydraulic friction engagement device. In FIG. 5, the first line pressure PL is used as the original pressure of the linear solenoid valve SLU. However, the modulator hydraulic pressure P _MOD may be used instead of the first line pressure PL.

As shown in FIG. 5, the lock-up control valve 64 is a type of two-position switching valve that is switched from the OFF position to the ON position when the lock-up engagement pressure _PSLU exceeds a predetermined value. The first oil passage L1 is closed, the second oil passage L2 is connected to the third oil passage L3, the first oil passage L1 is connected to the discharge oil passage EX, and the fourth oil passage L4 is connected to the cooler 68. And, the fifth oil passage L5 is connected to the sixth oil passage L6. The first oil passage L1 is an oil passage through which the torque converter out pressure P _TCout output from the hydraulic oil outflow port 20b of the torque converter 20 is guided. The second oil passage L2 is an oil passage through which a lockup engagement pressure PSLU adjusted by the linear solenoid valve _SLU is guided. The third oil passage L3 is an oil passage through which a lock-up ON pressure P _LUPON supplied to the control oil chamber 20d of the torque converter 20 is guided. The fourth oil passage L4 is an oil passage through which the second line oil pressure Psec adjusted by the second line pressure adjusting valve 69 is guided using the oil pressure relieved from the first line pressure adjusting valve 67 as a base pressure. The fifth oil passage L5 is an oil passage through which the modulator hydraulic pressure P _MOD adjusted to a constant value by the modulator valve 66 is guided. The sixth oil passage L6 is an oil passage through which the torque converter in-pressure _PTCin supplied to the front oil chamber 20e of the torque converter 20 is guided.

As shown in FIG. 5, the lock-up control valve 64 connects the first oil passage L1 to the third oil passage L3, closes the second oil passage L2, and closes the first oil passage L1 in the OFF position. The cooler 68 is connected, the fourth oil passage L4 is connected to the sixth oil passage L6, and the fifth oil passage L5 is closed. Lock-up control valve 64 comprises a spring 64a for biasing the spool to the OFF position side, an oil chamber 64b that accepts a lock-up engagement pressure P _SLU for biasing the spool to the ON position side ing. In the lockup control valve 64, when the lockup engagement pressure _PSLU is smaller than a predetermined value set relatively small, the spool valve element is held at the OFF position by the biasing force of the spring 64a. In the lockup control valve 64, when the lockup engagement pressure _PSLU is larger than the predetermined value, the spool valve element is held at the ON position against the urging force of the spring 64a. In the lockup control valve 64 of FIG. 5, the solid line indicates the flow path when the spool valve element is in the ON position, and the broken line indicates the flow path when the spool valve element is in the OFF position.

The hydraulic pressure supplied from the lockup control valve 64 to the control oil chamber 20d and the front oil chamber 20e in the torque converter 20 is switched by the hydraulic control circuit 54 configured as described above, whereby the lockup clutch 32 operates. The state is switched. First, the case where the lockup clutch 32 is in the slip state or the lockup on will be described. In the lockup control valve 64, when the lockup engagement pressure _{PSLU that} is larger than the predetermined value by the command signal output from the electronic control device 56 is supplied, the lockup control valve 64 is switched to the ON position, The lockup engagement pressure P _SLU is supplied to the control oil chamber 20 d of the torque converter 20, and the modulator hydraulic pressure P _MOD supplied to the lockup control valve 64 is supplied to the front oil chamber 20 e of the torque converter 20. That is, the lock-up engagement pressure _{P SLU} is supplied to the control oil chamber 20d as a lock-up on pressure _{P LupON,} modulator pressure _{P MOD} is supplied to the front side oil chamber 20e as a torque converter in pressure _{P TCIN.} When the lockup control valve 64 is switched to the ON position, the _{relationship among the} lockup on pressure P _LupON , the torque converter in pressure P _TCin, and the torque converter out pressure P _TCout is _{expressed as follows. LUPON} > torque converter in pressure P _TCin > torque converter out pressure P _TCout . As a result, the lockup ON pressure (engagement pressure) P _LupON of the control oil chamber 20d of the torque converter 20 is regulated by the linear solenoid valve SLU, so that the lockup differential pressure (P _LupON − (P _TCin + P _TCout )). / 2) ΔP is adjusted, and the operating state of the lock-up clutch 32 is switched in the range from the slip state to the lock-up on (complete engagement).

Next, a case where the lockup clutch 32 is locked off will be described. In the lock-up control valve 64, when the lock-up engagement pressure _PSLU is smaller than the predetermined value, the lock-up control valve 64 is switched to the OFF position by the biasing force of the spring 64a, and the hydraulic oil outflow port of the torque converter 20 The torque converter out pressure P _TCout output from 20b is supplied to the control oil chamber 20d of the torque converter 20, and the second line oil pressure Psec is supplied to the front oil chamber 20e of the torque converter 20. That is, the torque converter out pressure _PTCout is supplied to the control oil chamber 20d as the lockup on pressure _PLupON , and the second line oil pressure Psec is supplied to the front side oil chamber 20e as the torque converter in pressure _PTCin . When the lock-up control valve 64 is switched to the OFF position, the relationship _among the magnitudes of the lock-up on pressure P _LupON , the torque converter in pressure P _TCin, and the torque converter out pressure P _TCout depends on the torque converter in pressure. P _TCin > torque converter out pressure P _TCout > lockup on pressure P _LupON As a result, the operating state of the lockup clutch 32 is switched to lockup off.

Returning to FIG. 1, the vehicle 10 includes, for example, lock-up clutch control for controlling the lock-up engagement pressure P _SLU of the lock-up clutch 32, that is, the lock-up differential pressure ΔP, and hydraulic friction engagement at the time of shifting of the automatic transmission 22. An electronic control unit 56 is provided that performs shift control and the like for controlling the engagement pressure of the device via a hydraulic control circuit 54. FIG. 1 is a diagram showing an input / output system of the electronic control unit 56, and is a functional block for explaining a main part of a control function by the electronic control unit 56. The electronic control unit 56 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Each control of the vehicle 10 is executed by performing signal processing.

Various input signals detected by various sensors provided in the vehicle 10 are supplied to the electronic control unit 56. For example, a signal indicating the throttle valve opening θth (%) detected by the throttle valve opening sensor 70, a signal indicating the vehicle speed V (km / h) detected by the vehicle speed sensor 72, and an engine rotation sensor 74 are detected. A signal representing the engine speed Ne (rpm) of the engine 12, a signal representing the turbine speed Nt (rpm) of the turbine impeller 20 t of the torque converter 20 detected by the turbine speed sensor 76, and detected by the accelerator operation amount sensor 78. A signal representing the accelerator opening Acc (%) which is the operation amount of the accelerator pedal, a signal representing the actual oil temperature Toil (° C.) of the hydraulic oil in the torque converter 20 detected by the oil temperature sensor 80, and the hydraulic sensor 82 A signal representing the lockup engagement pressure P _SLU (kPa) of the lockup clutch 32 detected by Is input to the electronic control unit 56. Further, the electronic control unit 56 receives a shift command pressure Sat for hydraulic control related to the shift of the automatic transmission 22, a lockup command pressure Slu for controlling the switching of the operation state of the lockup clutch 32, and the like. Is output. The shift command pressure Sat is a command signal for driving the linear solenoid valves SL1 to SL6 that regulate the hydraulic pressure supplied to the hydraulic actuators (not shown) of the hydraulic friction engagement device. Are output to the linear solenoid valves SL1 to SL6. Further, the lock-up command pressure Slu is a command signal for driving the linear solenoid valve SLU for pressurizing regulating the lockup engagement pressure P _SLU, is output to the linear solenoid valve SLU of the hydraulic control circuit 54.

  The electronic control unit 56 shown in FIG. 1 includes a lock-up clutch control unit 90, a quick fill control end determination unit 92, a constant pressure standby control end determination unit 94, and a takeover control end condition establishment determination unit as main parts of the control function. 96 and a command pressure correction necessity determination unit 98. The lockup clutch control unit 90 includes a flex lockup control unit 90a, a flex lockup control start determination unit 90b, and a flex lockup control end determination unit 90c. In addition, the flex lockup control unit 90a includes a quick fill control execution unit 90d, a constant pressure standby control execution unit 90e, a takeover control execution unit 90f, and a differential rotation control execution unit 90g.

The lock-up clutch control unit 90 controls the lock-up differential pressure (P _LUPON − (P _TCin + P _TCout ) / 2) ΔP of the lock-up clutch 32, that is, the lock-up command pressure Slu of the lock-up engagement pressure P _SLU. Execute clutch control. The lockup clutch control unit 90 uses a predetermined relationship (lockup region diagram) having a lockup off region, a flex lockup region, and a complete lockup region with the vehicle speed V and the throttle valve opening θth as variables. Thus, it is determined whether the vehicle state represented by the actual vehicle speed V and the throttle valve opening θth is a lock-up off region, a flex lock-up region, or a complete lock-up region. The lockup command pressure Slu, which is a command signal, is controlled so that the lockup clutch 32 is in the corresponding operating state. In accordance with this lockup command pressure Slu, the linear solenoid valve SLU provided in the hydraulic control circuit 54 is driven (actuated) so that the operation state of the lockup clutch 32 becomes the operation state corresponding to the determined region.

When the flex lockup control unit 90a determines that the vehicle state is the flex lockup region based on the lockup region diagram in the lockup clutch control unit 90, the flex lockup control unit 90a performs torque without fully engaging the lockup clutch 32. The converter 20 controls the lockup command pressure Slu of the lockup engagement pressure P _SLU of the lockup clutch 32 so that the lockup clutch 32 slips between the pump impeller 20p and the turbine impeller 20t by a predetermined differential rotation. Execute flex lockup control. When the execution of the flex lockup control is started, as shown in FIG. 7, for example, quick fill control, constant pressure standby control, takeover control, and differential rotation control (basic control) are executed in this order. In FIG. 7, the first phase PH1 is a stage for executing quick fill control, the second phase PH2 is a stage for executing constant pressure standby control, and the third phase PH3 is a stage for executing takeover control, The fourth phase PH4 is a stage for executing the differential rotation control.

  The flex lockup control start determination unit 90b determines whether or not the flex lockup control unit 90a has started executing the flex lockup control. For example, when the flex lockup control start determination unit 90b determines that the vehicle state is the flex lockup region in the lockup region diagram of the lockup clutch control unit 90, the flex lockup control unit 90a It is determined that the lockup control has been started.

  When the flex lockup control end determination unit 90c determines that the flex lockup control start determination unit 90b has started executing the flex lockup control, the flex lockup control end determination unit 90c determines whether the flex lockup control has ended. For example, when the flex lockup control end determination unit 90c determines that the vehicle state is the lockup off region or the complete lockup region in the lockup region diagram in the lockup clutch control unit 90, the flex lockup control end determination unit 90c The up control unit 90a determines that the flex lockup control has ended.

  When the quick fill control execution unit 90d determines that the flex lockup control start determination unit 90b has started the flex lockup control, the quick fill control execution unit 90d executes the quick fill control as shown in the first phase PH1 of FIG. 7, for example. In the quick fill control, the lockup command pressure Slu of the linear solenoid valve SLU is maintained at the value Sa1 for a predetermined time tc1, and is lowered to a predetermined value Sa2 after the predetermined time tc1 has elapsed. The above value Sa1 is calculated by using, for example, a map stored in advance using, for example, the output torque Te of the engine 12 when the flex lockup control start determination unit 90b determines that the flex lockup control has been started. Is done. In addition, the quick fill control execution unit 90d ends the quick fill control when a predetermined time tc1 elapses after the quick fill control is started.

  When the quick fill control execution unit 90d starts the quick fill control, the quick fill control end determination unit 92 determines whether or not the quick fill control is ended. For example, the quick fill control end determination unit 92 determines that the quick fill control has ended when a predetermined time tc1 has elapsed since the quick fill control execution unit 90d started the quick fill control.

  If the constant pressure standby control execution unit 90e determines that the quick fill control end determination unit 92 has ended the quick fill control, the constant pressure standby control execution unit 90e executes constant pressure standby control as shown in the second phase PH2 of FIG. In the constant pressure standby control, the lockup command pressure Slu of the linear solenoid valve SLU is reduced to a value Sa3 at a preset constant sweep rate Ra1, and is set for a predetermined time tc2 that is predetermined at the value Sa3. maintain. The sweep rate Ra1 is indicated, for example, by the amount of decrease in the lockup command pressure Slu per time t (sec) that has elapsed since being decreased from the value Sa2 to the value Sa3. The value Sa3 is calculated by, for example, a map stored in advance using, for example, the output torque Te of the engine 12 when the quick fill control end determination unit 92 determines that the quick fill control has ended. In addition, the constant pressure standby control execution unit 90e ends the constant pressure standby control when a predetermined time tc3 has elapsed since the start of the constant pressure standby control.

  The quick fill control executed by the quick fill control execution unit 90d and the constant pressure standby control executed by the constant pressure standby control execution unit 90e are pack filling controls for quickly filling the pack clearance of the lockup clutch 32. The control execution unit 90d and the constant pressure standby control execution unit 90e have a function as a packing control unit that executes the packing control. Further, as shown in FIG. 3, the pack clearance is, for example, a clearance or a piston stroke from the position where the pressing member 48 provided in the lockup clutch 32 comes back to the first friction plate 38 from the position returned by the return spring 52. is there.

  The constant pressure standby control end determination unit 94 determines whether or not the constant pressure standby control has ended when the constant pressure standby control execution unit 90e starts the constant pressure standby control. For example, the constant pressure standby control end determination unit 94 determines that the constant pressure standby control has ended when a constant time tc3 has elapsed since the constant pressure standby control execution unit 90e started the constant pressure standby control.

When the takeover control execution unit 90f determines that the constant pressure standby control end determination unit 94 has ended the constant pressure standby control, the takeover control execution unit 90f starts the constant pressure standby control (packing control) as shown in the second phase PH2 of FIG. Takeover control is performed in which the lockup command pressure Slu of the lockup engagement pressure P _SLU is increased to take over to the differential rotation control. The takeover control is Sui lockup command pressure Slu lockup engagement pressure P _SLU for the lockup clutch 32 due to the constant pressure standby control is terminated at a constant pressure standby control termination determination unit 94 - given time flop rate Ra2 tc4 This is the control for starting the boosting control to boost the voltage during this period. The sweep rate Ra2 and the predetermined time tc4 are, for example, the output torque Te of the engine 12 when the constant pressure standby control end determination unit 94 determines that the constant pressure standby control has ended, the engine speed Ne, the turbine speed Nt, For example, the map is calculated using the oil temperature Toil or the like.

When the takeover control end condition establishment determination unit 96 starts the takeover control by the takeover control execution unit 90f, whether or not the condition for ending the takeover control is satisfied, that is, the step-up control is ended and the differential rotation control is started. It is determined whether or not a condition to be satisfied is satisfied. For example, the takeover control end condition establishment determination unit 96 is in a state where the difference between the actual differential rotation ΔN _CL of the lockup clutch 32 and the preset target differential rotation ΔN _CL * is equal to or less than a predetermined value A (ΔN _CL −ΔN _CL When * ≦ A) continues for a predetermined first time ta1 or more, it is determined that the condition for terminating the takeover control is satisfied. The differential rotation ΔN _CL is a differential rotation between the rotational speed of the pump impeller 20p, that is, the engine rotational speed Ne (rpm) and the rotational speed of the turbine impeller 20t, that is, the turbine rotational speed Nt (rpm). Further, for example, the handover control termination condition satisfaction judging unit 96, the lockup actual lockup engagement pressure P _SLU is preset pack clearance stroke end pressure P _END predetermined pressure α or from the packed high state of the clutch 32 ( When P _SLU ≧ P _END + α) and a preset second time ta2 has elapsed since the start of the boost control, it is determined that the condition for terminating the takeover control is satisfied. The predetermined pressure α is a pressure corresponding to the variation of the stroke end pressure _PEND .

When the takeover control end condition establishment determining unit 96 determines that the condition for ending the takeover control is established, the takeover control executing unit 90f ends the takeover control, and the differential rotation control executing unit 90g enters the fourth phase PH4 of FIG. The execution of the differential rotation control as shown is started. The differential rotation control is performed so that the pump impeller 20p and the turbine impeller 20t in the torque converter 20 are locked so that the actual differential rotation ΔN _CL of the lockup clutch 32 matches the preset target differential rotation ΔN _CL *. controlling the lockup command pressure Slu lockup engagement pressure _{P SLU} of up clutch 32.

When the instruction pressure calculation unit 90h provided in the differential rotation control execution unit 90g determines that the condition for ending the takeover control is established by the takeover control end condition establishment determination unit 96, the lockup engagement pressure P of the lockup clutch 32 is determined. For example, the feedback control equation (1) is used to calculate the lock-up command pressure Slu of the _SLU at every sampling time. However, _{C P} is the proportional gain, _{C I} is the integral gain, e1 is the difference between the target differential speed .DELTA.N _CL * and the rotational difference _{ΔN CL (ΔN CL * -ΔN CL} ).
Slu = C _P × e1 + C _I × ∫e1dt (1)

When the command pressure correction necessity determination unit 98 determines that the command pressure calculation unit 90h has calculated the lockup command pressure Slu, the command pressure correction necessity determination unit 98 determines whether or not the calculated lockup command pressure Slu needs to be corrected. For example, the command pressure correction necessity determination unit 98 calculates the calculated lockup command pressure when the deviation e2 between the model target differential rotation ΔN _CLM * (see FIG. 7) and the target differential rotation ΔN _CL * is equal to or greater than a predetermined value. It is determined that Slu needs to be corrected. The model target differential rotation ΔN _CLM * is calculated by using, for example, a map or the like using, for example, the lockup command pressure Slu when the command pressure calculation unit 90h calculates the lockup command pressure Slu. Alternatively, the model target differential rotation ΔN _CLM * is calculated by using, for example, a map or the like using the lockup command pressure Slu and the output torque Te of the engine 12 when the command pressure calculation unit 90h calculates the lockup command pressure Slu. You may do it.

When the correction unit 90i provided in the command pressure calculation unit 90h determines that the lockup command pressure Slu needs to be corrected by the command pressure correction necessity determination unit 98, the lockup command calculated by the command pressure calculation unit 90h. Correct the pressure Slu. For example, the correction unit 90i calculates the correction gain G using, for example, a map or the like using the deviation e2 between the model target difference rotation ΔN _CLM * and the target difference rotation ΔN _CL *, and the correction gain G is calculated using the above equation (1). by multiplying the proportional gain C _P and the integral gain C _I in correcting the lock-up command pressure Slu. Further, the correction unit 90i uses the deviation e2 between the model target difference rotation ΔN _CLM * and the target difference rotation ΔN _CL * to calculate the correction amount V1 using, for example, a map or the like, and the lockup instruction for calculating the correction amount V1 The lockup command pressure Slu may be corrected by adding to the pressure Slu.

  When the differential rotation control execution unit 90g determines that the flex lockup control is ended by the flex lockup control end determination unit 90c, the differential rotation control ends.

  FIG. 6 is a flowchart for explaining an example of the control operation of the takeover control in which the electronic control unit 56 takes over from the constant pressure standby control to the differential rotation control during the flex lockup control. FIG. 7 is a time chart when the control operation shown in the flowchart of FIG. 6 is executed. The time chart of FIG. 7 is a diagram showing flex lockup control during acceleration in the accelerator ON state where the accelerator pedal is depressed.

  First, in step (hereinafter, step is omitted) S1 corresponding to the function of the flex lockup control start determination unit 90b, it is determined whether or not the flex lockup control is started. If the determination in S1 is negative, this routine is terminated. If the determination in S1 is affirmative (time t1 in FIG. 7), S2 corresponding to the function of the quick fill control execution unit 90d is performed. Executed. In S2, quick fill control, which is one of pack packing controls for packing the pack clearance of the lockup clutch 32, is executed. Next, S3 corresponding to the function of the quick fill control end determination unit 92 is executed. In S3, it is determined whether or not the quick fill control has ended after a predetermined time tc1 has elapsed since the quick fill control was started. When the determination of S3 is negative, the above S2 is executed again, but when the determination of S3 is positive (time t2 in FIG. 7), S4 corresponding to the function of the constant pressure standby control execution unit 90e. Is executed. In S4, constant pressure standby control, which is one of pack packing controls for packing the pack clearance of the lockup clutch 32, is executed.

  Next, S5 corresponding to the function of the constant pressure standby control end determination unit 94 is executed. In S5, it is determined whether or not the constant pressure standby control has ended after a certain time tc3 has elapsed since the start of the constant pressure standby control. When the determination of S5 is negative, the above S4 is executed again. However, when the determination of S5 is positive (at time t3 in FIG. 7), S6 corresponding to the function of the takeover control execution unit 90f is executed. Executed. In S6, takeover control is executed. Next, S7 corresponding to the function of the takeover control end condition establishment determination unit 96 is executed. In S7, it is determined whether a condition for ending the takeover control is satisfied. When the determination of S7 is negative, the above S6 is executed again, but when the determination of S7 is affirmative (at time t4 in FIG. 7), S8 corresponding to the function of the instruction value calculation unit 90h is performed. Executed. In S8, the lockup command pressure Slu of the lockup clutch 32 for executing the differential rotation control is calculated. Next, S9 corresponding to the function of the command pressure correction necessity determination unit 98 is executed.

In S9, it is determined whether or not it is necessary to correct the lockup command pressure Slu calculated in S8. If the determination in S9 is negative, S10 corresponding to the function of the differential rotation control execution unit 90g is executed. If the determination in S9 is positive, S11 corresponding to the function of the correction unit 90i is performed. Executed. In S11, the lockup command pressure Slu calculated in S8 is corrected using the deviation e2 between the model target differential rotation ΔN _CLM * and the target differential rotation ΔN _CL *. In S10, differential rotation control is executed based on the lockup command pressure Slu. Next, S12 corresponding to the function of the flex lockup control end determination unit 90c is executed. In S12, it is determined whether or not the flex lockup control is finished. If the determination in S12 is negative, S8 is executed, but if the determination in S12 is positive, the present routine is terminated.

In the time chart of FIG. 7, the actual lock-up engagement pressure P _SLU of the lock-up clutch 32 is higher than the stroke end pressure P _END at which the preset pack clearance is filled by a predetermined pressure α and the pressure increase control. When the preset second time ta2 or more has elapsed (time t4) from the start of time (time t3), the boost control is terminated and the control is shifted from the takeover control to the differential rotation control.

As described above, according to the electronic control unit 56 of the power transmission device 16 of the present embodiment, the takeover control increases the lockup engagement pressure P _SLU of the lockup clutch 32 with the end of the pack control. When the pressure increase control is started and a state where the difference between the actual differential rotation ΔN _CL and the target differential rotation ΔN _CL * is equal to or less than the predetermined value A continues for a preset first time ta1 or the lock-up clutch 32 When the actual lock-up engagement pressure P _SLU is higher than the stroke end pressure P _{END at} which the pack clearance is reduced by a predetermined pressure α or more and a preset second time ta2 has elapsed since the start of the pressure increase control. The step-up control is terminated and the differential rotation control is started. Therefore, when the state where the difference between the actual differential rotation ΔN _CL and the target differential rotation ΔN _CL * is equal to or less than the predetermined value A continues for a preset first time ta1 or more, the differential rotation control starts. Since the actual differential rotation ΔN _CL * of the lockup clutch 32 is approaching the differential rotation ΔN _CL suitable for the above, the differential rotation control can be started. Further, the lock-up engagement pressure P _SLU of the lock-up clutch 32 is higher than the stroke end pressure P _{END at} which the pack clearance is reduced by a predetermined pressure α or more, and a preset second time ta2 has elapsed since the start of the pressure increase control. In this case, it is considered that the lock-up engagement pressure P _SLU of the lock-up clutch 32 is higher than the stroke end pressure P _END by a predetermined pressure α and the pack clearance is surely filled. Can start. Thus, as compared with those for executing the takeover control from packing controls the time to transition to the differential rotation control, for example, until the lock-up engagement pressure P _SLU for the lockup clutch 32 becomes equal to the predetermined pressure, preferably short can do.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

For example, the torque converter 20 of the above-described embodiment has a hydraulic oil supply port 20a, a hydraulic oil outlet port 20b, and a port that supplies the lockup engagement pressure _PSLU to the control oil chamber 20d, and lockup control is performed. The hydraulic pressure between the pressing member 48 and the front cover 34 is compressed by the movement of the pressing member 48 at the start of the operation, and the back pressure ((P _TCin + P _TCout ) / 2) increases. Other torque converters 20 For example, the present invention can be applied to a torque converter having a two-port structure in which the back pressure ((P _TCin + P _TCout ) / 2) is not applied.

  In the above-described embodiment, the torque converter 20 is used in the vehicle 10. However, a fluid transmission device (fluid coupling) having no torque amplification function may be used instead of the torque converter 20. .

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

16: Power transmission device (vehicle power transmission device)
20: Torque converter (fluid transmission)
20p: Pump impeller (input member)
20t: Turbine impeller (output member)
32: Lock-up clutch 56: Electronic control device (control device)
90a: Flex lockup control unit 90d: Quick fill control execution unit (packing control unit)
90e: Constant pressure standby control execution unit (packing control unit)
90f: takeover control execution part 90g: differential rotation control execution part 96: takeover control end condition establishment determination part A: predetermined value _PEND : stroke end pressure _PSLU : lockup engagement pressure (engagement pressure)
ta1: First time ta2: Second time α: Predetermined pressure ΔN _CL : Differential rotation ΔN _CL *: Target differential rotation

Claims (1)

A control device for a vehicle power transmission device including a fluid transmission device capable of directly connecting an input member and an output member by engagement of a lockup clutch,
A flex lockup control unit that controls the engagement pressure of the lockup clutch so that the lockup clutch slips at a predetermined differential rotation;
The flex lockup control unit is configured to quickly pack the pack clearance of the lockup clutch, and the lockup clutch so that an actual differential rotation of the lockup clutch matches a preset target differential rotation. A differential rotation control for controlling the engagement pressure of the control unit, and a takeover control for taking over the differential rotation control by increasing the engagement pressure from the end of the packing control,
The takeover control is
Along with the end of the packing control, start the pressure increase control to increase the engagement pressure of the lockup clutch,
When the state where the difference between the actual differential rotation and the target differential rotation is equal to or less than a predetermined value continues for a preset first time or more, or the engagement pressure of the lock-up clutch fills the pack clearance. A vehicle having a pressure higher than a stroke end pressure by a predetermined pressure or more, and when the preset second time or more has elapsed from the start of the pressure increase control, the pressure increase control is terminated and the differential rotation control is started. Power transmission device control device.

Images