JP6536509B2 - Control device of power transmission device for vehicle - Google Patents

Description

  The present invention controls the engagement pressure of the lockup clutch so that the actual differential rotation of the lockup clutch coincides with the preset target differential rotation, and packing control for quickly packing the pack clearance of the lockup clutch. In a control device of a power transmission apparatus for a vehicle, which executes differential rotation control and takeover control in which the engagement pressure is increased from the packing control to perform handover to the differential rotation control, the difference from the packing control is The present invention relates to a technique for suitably shortening the time for transition to rotation control.

  In a power transmission apparatus for a vehicle including a fluid transmission capable of directly coupling an input member and an output member by engagement of a lockup clutch, engagement of the lockup clutch so that the lockup clutch slips at a predetermined differential rotation. A flex lock-up control unit for controlling pressure, the flex lock-up control unit performing packing control for quickly packing the pack clearance of the lock-up clutch, and the actual setting of the lock-up clutch to a preset target differential rotation A vehicle power transmission device that executes differential rotation control that controls the engagement pressure of the lock-up clutch such that the differential rotations coincide with each other, and handover control that performs handover from the packing control to the differential rotation control. Control devices are known. For example, the control device of the power transmission device for a vehicle described in Patent Document 1 is that. In Patent Document 1, the flex lockup control of the lockup clutch is calculated by adding the first correction amount to the base indicated pressure in the first control phase until the friction material of the lockup clutch comes into contact substantially. For example, by subtracting the second correction amount from the base command pressure in the second control phase which is determined in consideration of the actual differential rotation so that the differential rotation of the lockup clutch approaches the target differential rotation from the boosted pressure-corrected command pressure. When switching to the command pressure after calculation and pressure reduction correction, the difference between the first correction amount before switching and the second correction amount after switching decreases at a predetermined rate of change regardless of the change in the base command pressure As described above, it is described that the switching transient command pressure at the time of switching from the pressure increase corrected command pressure to the pressure decrease corrected command pressure is controlled according to the change of the base command pressure. . Further, in Patent Document 1 described above, it is determined whether the switching transient command pressure has reached the post-decompression corrected command pressure that is the command pressure after switching, and the switching transient command pressure is the post-decompression command. The control is to be performed until it is equal to the pressure.

JP, 2013-19428, A

  By the way, in the control apparatus of the power transmission apparatus for vehicles like the above-mentioned patent documents 1, when shifting from the 1st control phase to the 2nd control phase, ie, from packing control which packs the pack clearance of a lockup clutch, When transitioning to differential rotation control to control the engagement pressure of the lock-up clutch so that the actual differential rotation of the lock-up clutch coincides with a preset target differential rotation, the switching transient command pressure is reduced The control for taking over from the packing control to the differential rotation control is executed until the post-correction instruction pressure becomes equal to the command pressure, ie, until the engagement pressure of the lock-up clutch becomes equal to a predetermined pressure. The robustness of the clutch control is low and the time to shift from the packing control to the differential rotation control is long 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 described above, and an object thereof is to provide a control device of a power transmission apparatus for a vehicle which suitably shortens the time for shifting from packing control to differential rotation control. It is to do.

  According to a first aspect of the present invention, there is provided: (a) a power transmission apparatus for a vehicle including a fluid transmission capable of directly connecting an input member and an output member by engagement of a lockup clutch; The flex lock up control unit controls an engagement pressure of the lock up clutch so that the lock up clutch slips, and (c) the flex lock up control unit quickly packs the pack clearance of the lock up clutch. From the end of the packing control, the differential rotation control for controlling the engagement pressure of the lock-up clutch so that the actual differential rotation of the lock-up clutch coincides with the preset target differential rotation, and from the end of the packing control Performing handover control for increasing the engagement pressure and performing handover to the differential rotation control, and (d) performing the handover control The pressure increase control for increasing the engagement pressure of the lock-up clutch is started with the end of the packing control, and (e) the difference between the actual differential rotation and the target differential rotation is less than or equal to a predetermined value. When continuing for a preset first time or more, or the engagement pressure of the lock-up clutch is a predetermined pressure or more higher than the stroke end pressure at which the pack clearance is filled, and the preset from the start of the pressure increase control When two hours or more have elapsed, the boosting control is ended and the differential rotation control is started.

  According to the first aspect of the invention, the changeover control starts boost control for boosting the engagement pressure of the lockup clutch with the end of the packing control, and the difference between the actual differential rotation and the target differential rotation When the state in which the value of L falls below a predetermined value continues for a preset first time or longer, or the engagement pressure of the lockup clutch is higher than the stroke end pressure at which the pack clearance is filled, the pressure increase control When the second time or more set in advance has elapsed from the start of the step, the boost control is ended and the differential rotation control is started. For this reason, when the state in which the difference between the actual differential rotation and the target differential rotation is equal to or less than a predetermined value continues for a predetermined first time or longer, the differential rotation suitable for the start of the differential rotation control Since the actual differential rotation of the lockup clutch is approaching, the differential rotation control can be started. Further, when the engagement pressure of the lockup clutch is higher than the stroke end pressure at which the pack clearance is filled by a predetermined pressure or more, and the second time or more set in advance has elapsed from the start of the pressure increase control, the lockup is performed. 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 reliably filled, the differential rotation control can be started. Thereby, the time for shifting from the packing control to the differential rotation control can be suitably shortened, for example, as compared with the one in which the engagement control of the lockup clutch becomes equal to the predetermined pressure. .

While demonstrating the schematic structure of the vehicle to which this invention is applied, it is a figure explaining the control function for various control in a vehicle. It is a skeleton figure explaining an example of the torque converter provided in the vehicle of FIG. 1, and an automatic transmission. It is sectional drawing of the torque converter of FIG. 5 is an engagement operation table for explaining the relationship between the shift operation of the automatic transmission of FIG. 2 and the combination of the operation of the hydraulic friction engagement device used therein. FIG. 5 is a circuit diagram showing 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. 9 is a flowchart illustrating an example of 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; FIG. 7 is a time chart when the control operation shown in the flowchart of FIG. 6 is performed.

  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 and shapes of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a view for explaining a schematic configuration of a vehicle 10 to which the present invention is applied, and also a view for explaining a main part of a control system for various control in the vehicle 10. In FIG. 1, a vehicle 10 includes an engine 12, a drive wheel 14, and a vehicle power transmission device 16 (hereinafter referred to as a power transmission device 16) provided on a power transmission path between the engine 12 and the drive wheel 14. Is equipped. The power transmission device 16 includes a torque converter (fluid transmission) 20 and an automatic transmission 22 disposed in a case 18 (see FIG. 2) as a non-rotational member attached to a vehicle body, and an output rotation of the automatic transmission 22. The transmission output gear 24, which is a member, is provided with a differential gear device (differential gear) 26 connected to the ring gear 26a, and a pair of axles 28 and the like connected to the differential gear device 26. In the power transmission 16, the power output from the engine 12 is transmitted to the drive wheels 14 sequentially through the torque converter 20, the automatic transmission 22, the differential gear device 26, the axle 28 and the like.

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

  FIG. 2 is a skeleton view illustrating an example of the torque converter 20 and the automatic transmission 22. As shown in FIG. The torque converter 20 and the automatic transmission 22 etc. are configured substantially symmetrically with respect to the axial center RC of the transmission input shaft 30, which is an input rotary member of the automatic transmission 22, and in FIG. The lower half of the RC is omitted.

As shown in FIGS. 2 and 3, the torque converter 20 has a front cover 34 and a rear cover 35 welded together, and a plurality of pump blades 20 f fixed inside 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 which is disposed to rotate around the axial center RC, is opposed to the rear cover 35 and is connected to the transmission input shaft 30 so as to be able to transmit power. And the turbine wheel (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 . As described above, the torque converter 20 functions as a fluid power transmission device for a vehicle with the lockup clutch 32 provided in the power transmission path between the engine 12 and the automatic transmission 22. Further, the power transmission device 16 is provided with a mechanical oil pump 33 coupled 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 shift-control 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 (discharge) hydraulic pressure for

  The lock-up clutch 32 is a hydraulic multi-plate friction clutch (wet multi-plate clutch), and as shown in FIG. 3, the lock-up clutch 32 has a front cover 34 integrally connected with the pump impeller 20p. Is engaged with the first annular member 36 fixed by welding to the outer circumferential spline teeth 36a formed on the outer periphery of the first annular member 36 so as to be relatively nonrotatable around the axial center RC and movable in the axial center RC direction It is connected to the transmission input shaft 30 and the turbine impeller 20t so that power can be transmitted via a plurality of (three in this embodiment) annular first friction plates 38 and the damper device 40 provided in the torque converter 20. The second annular member 42 and the inner spline teeth 42a formed on the inner periphery of the second annular member 42 are engaged non-rotatably around the axial center RC and movably in the axial center RC direction. A plurality of (two in this embodiment) annular second friction plates 44 disposed between the plurality of first friction plates 38 and a transmission input shaft fixed to the inner peripheral portion 34 a of the front cover 34 An annular pressing member (piston) 48 supported movably in the direction of the axial center RC by a hub member 46 rotatably supporting an end of the front cover 34 on the side of the front cover 34 about the axial center RC. And an annular fixing member 50 supported at a fixed position on the hub member 46 and disposed opposite to the pressing member 48 on the opposite side of the pressing member 48 to the front cover 34 side, and the pressing member 48 as an axial center A return spring 52 is provided which biases the fixing member 50 in the RC direction, ie, biases the pressing member 48 in a direction 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 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 is formed which has a hydraulic oil outflow port 20b through which the hydraulic oil flows out. Further, the lockup clutch 32 and the first friction material 38 and the second friction material 44 of the lockup clutch 32 for engaging the lockup clutch 32 are pressed into the main oil chamber 20 c of the torque converter 20. For example, a control oil chamber 20d for supplying a lockup engagement pressure _PSLU for urging the pressing member 48 to the front cover 34 side, that is, a pressing member 48 for releasing the lockup clutch 32, the front cover 34 side. And hydraulic fluid from the front oil chamber 20e in communication with the front oil chamber 20e and the front oil chamber 20e to which the second line hydraulic pressure Psec to be described later, for example, to be urged to the opposite side is supplied. A rear side oil chamber 20g is provided to allow the hydraulic oil to flow out of the hydraulic oil outlet port 20b. The control oil chamber 20 d is an oil-tight space formed between the pressing member 48 and the fixing member 50, and the front side oil chamber 20 e is formed between the pressing member 48 and the front cover 34. The rear side oil chamber 20g is a space excluding the control oil chamber 20d and the front side oil chamber 20e in the main oil chamber 20c.

In the torque converter 20, as shown in FIG. 3, for example, the oil pressure supplied to the control oil chamber 20d, that is, the lockup on pressure P _LupON (kPa) is relatively large (the oil pressure of the front side oil chamber 20e, ie, the torque converter When P _TCin (kPa) is relatively small and the pressing member 48 is urged to move to the front cover 34 as indicated by the alternate long and _short dash line, the first friction plate 38 and the second friction are moved by the pressing member 48. 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 coupled. Also, for example, when the lockup on pressure P _LupON (kPa) of the control oil chamber 20 d is relatively small (the torque converter in pressure P _TCin (kPa) of the front side oil chamber 20 e is relatively large), the pressing member 48 is As shown by the solid line, when moved to a position separated from the first friction plate 38, the pump impeller 20p connected to the first annular member 36 and the turbine impeller 20t connected to the second annular member 42 are relative to each other 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 has a lockup on pressure P _LupON (kPa) in the control oil chamber 20d, a torque converter in pressure P _TCin (kPa) in the front side oil chamber 20e, and a torque output from the hydraulic oil outflow port 20b. _Transfer based on a differential pressure with 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 _TCn + P _TCout ) / 2) The torque is controlled. The above-mentioned _{expression of} lockup differential pressure (engagement pressure) ΔP = P _LupON − (P _TCin + P _TCout ) / 2 is an empirical equation previously determined by experiment or the like. In the above equation, the torque converter in pressure P _TCin and the torque converter out pressure P _TCout are the engine rotational speed Ne (rpm), the turbine rotational speed Nt (rpm), and their differential rotation (engine rotational speed-turbine rotational speed) It changes with (DELTA) N (rpm), 2nd line oil pressure Psec (kPa), ATF oil temperature Toil (degreeC), engine torque Te (Nm), etc. The torque converter out pressure P _TCout is changed by changes in engine rotational speed Ne, turbine rotational speed Nt, ATF oil temperature Toil, etc., and changes in centrifugal hydraulic pressure in the rear side oil chamber 20g of the torque converter 20. Do.

  The lockup differential pressure ΔP is controlled by the electronic control unit (control unit) 56 via the hydraulic control circuit (hydraulic pressure circuit) 54 so that, for example, the lockup differential pressure ΔP is made negative. A so-called lock-up release 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 clutch 32 is partially engaged with slippage when the lockup differential pressure ΔP is made zero or more. The lock-up differential pressure ΔP is maximized and the lock-up clutch 32 is fully engaged in a so-called lock-up state (lock-up on) in which the lock-up clutch 32 is fully engaged. In the torque converter 20, even if the lockup clutch 32 is in the lockup state, the lockup slip state, or the lockup release state, the front oil chamber 20e and the rear oil chamber 20g are the same chamber, ie, the front 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 directed from the hydraulic oil supply port 20a to 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 wheels 14 and includes a plurality of hydraulic friction engagement devices (first clutch C1 to fourth clutch C4, first brake B1, second 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. It is a gear type multistage transmission. For example, it is a stepped transmission that performs so-called clutch-to-clutch shifting that is often used in vehicles. The automatic transmission 22 is an coaxial line of a double pinion type first planetary gear unit 58, and a single pinion type second planetary gear unit 60 and a double pinion type third planetary gear unit 62 configured in a Ravigneaux type. (On the axis RC), the rotation of the transmission input shaft 30 is changed in speed, and output from the transmission output gear 24.

  The first planetary gear set 58 includes a first sun gear S1 which is an external gear, a first ring gear R1 which is an internal gear concentric with the first sun gear S1, a first sun gear S1, and a first ring gear R1. And a first carrier CA1 supporting the first pinion gear P1 so as to be capable of rotating and revolving.

  The second planetary gear device 60 includes a second sun gear S2 which is an external gear, a second ring gear R2 which is an internal gear concentric 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 rotatably and revolvably.

  The third planetary gear set 62 includes a third sun gear S3 which is an external gear, a third ring gear R3 which is an internal gear concentric with the third sun gear S3, and a third sun gear S3 and a third ring gear thereof. It has a third pinion gear P3 consisting of a pair of gear pairs meshing with R3, and a third carrier CA3 supporting the third pinion gear P3 rotatably and revolvably.

  By controlling the engagement and release of these hydraulic friction engagement devices, as shown in the engagement operation table of FIG. 4, eight forward gears and one reverse gear depending on the driver's accelerator operation, vehicle speed V, etc. Each gear of the gear is formed. In FIG. 4, "1st"-"8th" mean the first gear-eighth gear as the forward gear, and "Rev" means the reverse gear 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 calculated by the first planetary gear set 58, the second planetary gear set 60, and the third planetary gear set It is appropriately determined by each gear ratio of the gear device 62 (= number of teeth of sun gear / number of teeth of ring gear).

As shown in FIG. 5, in the hydraulic control circuit 54, the lockup control valve 64 and the first line adjusted by the first line pressure adjusting valve 67 of the relief type using the hydraulic pressure generated from the oil pump 33 as the original pressure. A linear solenoid valve _SLU that regulates the hydraulic pressure PL to a lockup engagement pressure PSLU and a modulator valve 66 that regulates the modulator hydraulic pressure P _MOD to a fixed value with the first line hydraulic pressure PL as a source pressure are provided. The hydraulic control circuit 54 is provided with linear solenoid valves SL1 to SL6 (see FIG. 1) for controlling the operation of the hydraulic actuators (not shown) of the hydraulic friction engagement device. Although the first line pressure PL is used as the source pressure of the linear solenoid valve SLU in FIG. 5, the modulator hydraulic pressure P _MOD may be used instead of the first line pressure PL.

Further, as shown in FIG. 5, the lockup control valve 64 is a two-position switching valve of a type that can be switched from the OFF position to the ON position when the lockup 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 to which the torque converter out pressure P _TCout output from the hydraulic oil outlet port 20b of the torque converter 20 is introduced. The second oil passage L2 is an oil passage to which the lockup engagement pressure PSLU adjusted by the linear solenoid valve _SLU is introduced. The third oil passage L3 is an oil passage to which the lockup on pressure _PLupON supplied to the control oil chamber 20d of the torque converter 20 is introduced. The fourth oil passage L4 is an oil passage through which the second line oil pressure Psec adjusted by the second line pressure adjustment valve 69 is introduced, using the oil pressure relieved from the first line pressure adjustment valve 67 as an original pressure. The fifth oil passage L5 is an oil passage through which the modulator hydraulic pressure P _MOD regulated to a constant value by the modulator valve 66 is introduced. The sixth oil passage L6 is an oil passage to which the torque converter in pressure P _TCin supplied to the front side oil chamber 20e of the torque converter 20 is introduced.

Further, as shown in FIG. 5, in the OFF position, the lockup control valve 64 connects the first oil passage L1 to the third oil passage L3, closes the second oil passage L2, and causes the first oil passage L1 to be closed. It connects to the cooler 68, connects the fourth oil passage L4 to the sixth oil passage L6, and closes the fifth oil passage L5. 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 in 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 in the ON position against the biasing 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 control circuit 54 configured as described above switches the hydraulic pressure supplied from the lock-up control valve 64 to the control oil chamber 20 d and the front-side oil chamber 20 e in the torque converter 20 to operate the lock-up clutch 32. The state is switched. First, the case where the lockup clutch 32 is in the slip state or the lockup on state will be described. In the lockup control valve 64, when the lockup engagement pressure P _{SLU which} is larger than the predetermined value is supplied by the command signal output from the electronic control unit 56, the lockup control valve 64 is switched to the ON position. the lock-up engagement pressure _{P SLU} is supplied to the control oil chamber 20d of the torque converter 20, the modulator pressure _{P MOD} supplied to the lock-up control valve 64 is supplied to the front side oil chamber 20e 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 between the lockup on pressure _PLUPON , the torque converter in pressure P _TCin, and the torque converter out pressure P _TCout is the lockup on pressure P. _{Lup ON} > 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 20 d of the torque converter 20 is _adjusted by the linear solenoid valve SLU, whereby the lockup differential pressure (P _LupON − (P _TCin + P _TCout ) / 2) ΔP is adjusted, and the operating state of the lockup clutch 32 is switched in the range from the slip state to the lockup on (full engagement).

Next, the case where the lockup clutch 32 is turned off will be described. In the lockup control valve 64, when the lockup engagement pressure P _SLU is smaller than the predetermined value, the lockup 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 20 b is supplied to the control oil chamber 20 d of the torque converter 20, and the second line oil pressure Psec is supplied to the front side oil chamber 20 e 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 _PLon , and the second line oil pressure Psec is supplied to the front side oil chamber 20e as the torque converter in pressure _PTCin . In addition, when the lockup control valve 64 is switched to the OFF position, the relationship _among the sizes of the lockup on pressure _PLUPON , the torque converter in pressure _PTCin, and the torque converter out pressure _PTCout is 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 performs, 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 which executes, via a hydraulic control circuit 54, a shift control or the like for controlling the engagement pressure of the device. 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 of the electronic control unit 56. As shown in FIG. The electronic control unit 56 is configured to include, for example, a so-called microcomputer provided with a CPU, a RAM, a ROM, an input / output interface and the like, and the CPU follows a program stored in advance in the ROM using a temporary storage function of the RAM. Each control of the vehicle 10 is executed by performing signal processing.

The electronic control unit 56 is supplied with various input signals detected by various sensors provided in the vehicle 10. For example, a signal representing the throttle valve opening θth (%) detected by the throttle valve opening sensor 70, a signal representing the vehicle speed V (km / h) detected by the vehicle speed sensor 72, detected by the engine rotation sensor 74 A signal representing the engine rotation speed Ne (rpm) of the engine 12, a signal representing the turbine rotation speed Nt (rpm) of the turbine wheel 20t of the torque converter 20 detected by the turbine rotation sensor 76, detected by the accelerator operation amount sensor 78 A signal representing an accelerator opening Acc (%) which is an operation amount of an accelerator pedal, a signal representing an actual oil temperature Toil (.degree. C.) of hydraulic oil in the torque converter 20 detected by the oil temperature sensor 80, an oil pressure sensor 82 Such as a signal representing the lockup engagement pressure P _SLU (kPa) of the lockup clutch 32 detected by the Is input to the electronic control unit 56. Further, from the electronic control unit 56, a shift instruction pressure Sat for oil pressure control relating to the shift of the automatic transmission 22, and a lockup instruction pressure Slu etc. for switching control of the operation state of the lockup clutch 32 are respectively provided. It is output. The shift instruction pressure Sat is an instruction signal for driving the linear solenoid valves SL1 to SL6 that adjust the hydraulic pressure supplied to the hydraulic actuators (not shown) of the hydraulic friction engagement device, and the hydraulic control circuit 54 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 lockup clutch control unit 90, a quick fill control termination determination unit 92, a constant pressure standby control termination determination unit 94, and a handover control termination condition satisfaction determination unit as main parts of control functions. And 96 and a command pressure correction necessity determination unit 98. The lockup clutch control unit 90 further includes a flex lockup control unit 90a, a flex lockup control start determination unit 90b, and a flex lockup control end determination unit 90c. Further, the flex lockup control unit 90a has a quick fill control execution unit 90d, a constant pressure standby control execution unit 90e, a handover control execution unit 90f, and a differential rotation control execution unit 90g.

Lock-up clutch control section 90, the lock-up differential pressure of the lock-up clutch _{32 (P LupON - (P TCin} + P TCout) / 2) ΔP or locked up for controlling the lock-up command pressure Slu lockup engagement pressure _{P SLU} Execute clutch control. 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 vehicle speed V and throttle valve opening degree θth as variables. It is determined whether the vehicle state represented by the actual vehicle speed V and the throttle valve opening degree θth is any one of a lockup off area, a flex lockup area, and a complete lockup area. The lockup instruction pressure Slu, which is an instruction signal, is controlled so that the operation state of the lockup clutch 32 becomes the corresponding operation state. In accordance with the lockup command pressure Slu, the linear solenoid valve SLU provided in the hydraulic control circuit 54 is driven (actuated) so that the lockup clutch 32 is actuated to the actuation state corresponding to the determined region.

If the flex lockup control unit 90a determines that the vehicle state is the flex lockup region in the lockup region diagram of the lockup clutch control unit 90, the torque does not cause the lockup clutch 32 to be completely engaged. as the lock-up clutch 32 and the pump impeller 20p and the turbine impeller 20t at a predetermined differential rotation slips in the converter 20, controls the lock-up command pressure Slu lockup engagement pressure P _SLU for the lockup clutch 32 Execute flex lockup control. When the execution of the flex lockup control starts, for example, as shown in FIG. 7, the control is executed in the order of quick fill control, constant pressure standby control, takeover control, and differential rotation control (basic control) described later. Further, in FIG. 7, the first phase PH1 is a step of executing quick fill control, the second phase PH2 is a step of executing constant pressure standby control, and the third phase PH3 is a step of executing takeover control, The fourth phase PH4 is a step of executing differential rotation control.

  The flex lockup control start determination unit 90b determines whether the flex lockup control has been started by the flex lockup control unit 90a. For example, in the flex lockup control start determination unit 90b, when it is determined that the vehicle state is the flex lockup region in the lockup area diagram of the lockup clutch control unit 90, the flex lockup control unit 90a performs flexing. It is determined that execution of lockup control has started.

  When the flex lockup control start determination unit 90b determines that the flex lockup control has been started, the flex lockup control end determination unit 90c determines whether the flex lockup control is ended. For example, if it is determined that the vehicle state is the lockup off area or the complete lockup area in the lockup area diagram of the lockup clutch control section 90 in the flex lockup control termination determination section 90c, flex lock is determined. It is determined that the flex lockup control is ended by the up control unit 90a.

  If it is determined that the flex lockup control start determination unit 90b has started the execution of the flex lockup control, the quickfill control execution unit 90d executes the quickfill control as illustrated in, for example, the first phase PH1 of FIG. The quick fill control maintains the lockup instruction pressure Slu of the linear solenoid valve SLU at the value Sa1 for a predetermined constant time tc1, and reduces it to a predetermined value Sa2 after the constant time tc1 has elapsed. The value Sa1 is calculated, for example, by a map stored in advance using the output torque Te of the engine 12 when it is determined that the flex lockup control has been started by the flexlockup control start determination unit 90b. Be done. In addition, the quick fill control execution unit 90d ends the quick fill control when a predetermined time tc1 has elapsed since the start of the quick fill control.

  When the quick fill control execution unit 90d starts the quick fill control, the quick fill control end determination unit 92 determines whether the quick fill control has 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 90 d starts the quick fill control.

  If it is determined that the quick fill control end determination unit 92 has finished the quick fill control, the constant pressure standby control execution unit 90 e executes the constant pressure standby control as shown in the second phase PH2 of FIG. 7. The constant pressure standby control reduces the lock-up instruction pressure Slu of the linear solenoid valve SLU to a value Sa3 at a preset constant sweep rate Ra1 for a predetermined time tc2 predetermined at the value Sa3. maintain. The sweep rate Ra1 is indicated, for example, by the amount of decrease of the lockup command pressure Slu per time t (sec) which has elapsed from the value Sa2 to the value Sa3. The value Sa3 is calculated by, for example, a map stored in advance, using the output torque Te of the engine 12 when it is determined by the quick fill control end determination unit 92 that the quick fill control has ended. In addition, the constant pressure standby control execution unit 90 e terminates 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 packing control for quickly packing the pack clearance of the lockup clutch 32, and the quick fill control The control execution unit 90 d and the constant pressure standby control execution unit 90 e 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 gap or a piston stroke from the position where the pressing member 48 provided to the lockup clutch 32 is returned by the return spring 52 to abuts on the first friction plate 38. is there.

  When the constant pressure standby control execution unit 90 e starts the constant pressure standby control, the constant pressure standby control end determination unit 94 determines whether the constant pressure standby control has ended. For example, the constant pressure standby control end determination unit 94 determines that the constant pressure standby control is ended when the constant pressure standby control is started by the constant pressure standby control execution unit 90 e and after a predetermined time tc3 elapses.

If it is determined that the constant pressure standby control end determination unit 94 has ended the constant pressure standby control, the handover control execution unit 90 f starts the constant pressure standby control (packing control) as shown in the second phase PH2 of FIG. increasing the lock-up command pressure Slu lockup engagement pressure P _SLU executes takeover control for handover to the differential rotation control. In the above-described transfer control, the lockup instruction pressure Slu of the lockup engagement pressure P _SLU of the lockup clutch 32 is set at a sweep rate Ra2 for a predetermined time tc4 when the constant pressure standby control end determination unit 94 terminates the constant pressure standby control. It is control to start boost control for boosting during the period of time. The sweep rate Ra2 and the constant time tc4 are, for example, the output torque Te of the engine 12, the engine speed Ne, the turbine speed Nt, when the constant pressure standby control end determination unit 94 determines that the constant pressure standby control has ended. For example, it is calculated by a map etc. using oil temperature Toil etc.

The handover control termination condition satisfaction determination unit 96, when the handover control execution unit 90f starts handover control, determines whether a condition for terminating the handover control is satisfied, that is, terminates the pressure increase control and starts the differential rotation control. It is determined whether or not the condition to be satisfied is established. For example, in the handover control termination condition satisfaction determining unit 96, a state in which the difference between the actual differential rotation ΔN _CL of the lockup clutch 32 and the target differential rotation ΔN _CL * set in advance is equal to or less than a predetermined value A (ΔN _CL −ΔN _CL When * ≦ A) continues for the first time ta1 or more determined in advance, it is determined that the condition for ending the handover control is satisfied. Incidentally, the rotational difference .DELTA.N _CL is a rotational difference between the rotational speed, that is, to the engine rotational speed Ne of the pump impeller 20p (rpm), the rotational speed i.e. the turbine rotational speed Nt of the turbine wheel 20t (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 P _END + α) and the second time ta2 or more set in advance has elapsed from the start of the boost control, it is determined that the condition for terminating the handover control is satisfied. The predetermined pressure α is a pressure corresponding to the variation of the stroke end pressure P _END .

When the handover control termination condition satisfaction determination unit 96 determines that the condition for terminating the handover control is satisfied, the handover control execution unit 90 f terminates the handover control, and the differential rotation control execution unit 90 g performs the fourth phase PH4 of FIG. 7. Start the execution of differential rotation control as shown. The differential rotation control locks the pump impeller 20p and the turbine impeller 20t in the torque converter 20 such that the actual differential rotation ΔN _CL of the lockup clutch 32 matches the target differential rotation ΔN _CL * set in advance. controlling the lockup command pressure Slu lockup engagement pressure _{P SLU} of up clutch 32.

When the command pressure calculation unit 90h provided in the differential rotation control execution unit 90g determines that the condition for ending handover control is satisfied in the handover control termination condition satisfaction determination unit 96, the lockup engagement pressure P of the lockup clutch 32 is established. The lockup instruction pressure Slu of the _SLU is calculated at each sampling time using, for example, the feedback control equation (1). Here, C _P is a proportional gain, C _I is an integral gain, and e 1 is a deviation (ΔN _CL * −ΔN _CL ) between the target difference rotation ΔN _CL * and the difference rotation ΔN _CL .
Slu = C _P × e 1 + C _I × ∫ e 1 dt (1)

When determining that the lockup instruction pressure Slu has been calculated by the instruction pressure calculation unit 90h, the instruction pressure correction necessity determination unit 98 determines whether it is necessary to correct the calculated lockup instruction pressure Slu. For example, when the deviation e2 between the model target differential rotation ΔN _CLM * (see FIG. 7) and the target differential rotation ΔN _CL * is greater than or equal to a predetermined value, the directive pressure correction necessity determination unit 98 calculates the lockup directive pressure Determine that Slu needs to be corrected. The model target differential rotation ΔN _CLM * is calculated by, for example, a map or the like, using the lockup command pressure Slu or the like when the lockup command pressure Slu is calculated by the command pressure calculating unit 90 h. Alternatively, the model target differential rotation ΔN _CLM * is calculated by, for example, a map or the like using the lockup command pressure Slu and the output torque Te of the engine 12 when the lockup command pressure Slu is calculated by the command pressure calculation unit 90h. You may.

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

  When it is determined by the flex lockup control end determination unit 90c that the differential lock control execution unit 90g has ended the flex lockup control, the differential rotation control is ended.

  FIG. 6 is a flow chart for explaining an example of 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 unit 56. 7 is a time chart when the control operation shown in the flowchart of FIG. 6 is performed. In addition, the time chart of FIG. 7 is a figure which shows flex lockup control at the time of acceleration in the accelerator ON state in which 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 the flex lockup control has started. When the determination of S1 is negative, this routine is ended, but when the determination of S1 is affirmative (at time t1 in FIG. 7), S2 corresponding to the function of the quick fill control execution unit 90d is To be executed. In S2, quick fill control, which is one of the packing control 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 start of the quick fill control. If the determination in S3 is negative, the above S2 is executed again, but if the determination in S3 is affirmative (at 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 packing control 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 predetermined time tc3 has elapsed since the start of the constant pressure standby control. If the determination in S5 is negative, the above S4 is executed again, but if the determination in S5 is affirmed (time t3 in FIG. 7), S6 corresponding to the function of the handover control executor 90f is To be executed. In S6, takeover control is executed. Next, S7 corresponding to the function of the handover control termination condition satisfaction determination unit 96 is executed. At S7, it is determined whether a condition for ending the handover control is satisfied. If the determination in S7 is negative, the above S6 is executed again, but if the determination in S7 is affirmed (time t4 in FIG. 7), S8 corresponding to the function of the instruction value calculation unit 90h is To be executed. In S8, a lockup instruction pressure Slu of the lockup clutch 32 for performing differential rotation control is calculated. Next, S9 corresponding to the function of the command pressure correction necessity determination unit 98 is executed.

At S9, it is determined whether there is a need to correct the lockup command pressure Slu calculated at S8. If the determination of S9 is negative, S10 corresponding to the function of the differential rotation control execution unit 90g is executed, but if the determination of S9 is positive, S11 corresponding to the function of the correction unit 90i is To be executed. At S11, the lockup command pressure Slu calculated at 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 termination determination unit 90c is executed. In S12, it is determined whether the flex lockup control has ended. If the determination in S12 is negative, the above-described S8 is executed, but if the determination in S12 is affirmative, this routine is ended.

In the time chart of FIG. 7, the actual lockup engagement pressure P _SLU of the lockup clutch 32 is higher by a predetermined pressure α or more than the stroke end pressure P _END at which the pack clearance set in advance is filled. When the second time ta2 or more set in advance has elapsed from the start of (t3) (t4), the boost control is ended, and the transition control is shifted to the differential rotation control.

As described above, according to the electronic control unit 56 of the power transmission device 16 of this embodiment, the changeover control increases the lockup engagement pressure P _SLU of the lockup clutch 32 with the end of the packing control. The boost control is started, and the state where the difference between the actual differential rotation ΔN _CL and the target differential rotation ΔN _CL * becomes equal to or less than the predetermined value A continues for the preset first time ta1 or longer, or the lockup clutch 32 The actual lockup engagement pressure P _SLU is higher than the stroke end pressure P _END by which the pack clearance is filled by a predetermined pressure α or more, and the preset second time ta 2 or more has elapsed since the start of the pressure increase control. The boost control is ended and the differential rotation control is started. For this reason, when the state in which the difference between the actual differential rotation ΔN _CL and the target differential rotation ΔN _CL * is less than or equal to the predetermined value A continues for the preset first time ta1 or more, the start of the differential rotation control Since the actual differential rotation .DELTA.N _CL * of the lockup clutch 32 approaches the differential rotation .DELTA.N _CL suitable for the above, the differential rotation control can be started. The lock-up engagement pressure P _SLU for the lockup clutch 32 pack clearance stroke end predetermined pressure α or higher than pressure P _END be packed, it has elapsed and the second time ta2 least a preset from the start of the boost control case, it is considered that the lock-up engagement pressure P _SLU is the stroke end predetermined pressure α the above pressure P _eND is higher state the pack clearance of the lock-up clutch 32 is reliably filled, the differential speed control Can be started. 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.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is also applicable in other aspects.

For example, the torque converter 20 according to the above-described embodiment has the hydraulic oil supply port 20a, the hydraulic oil outflow port 20b, and the port for supplying the lockup engagement pressure _PSLU to the control oil chamber 20d, and performs lockup control. When the pressure member 48 is moved at the start of the operation, the hydraulic oil between the pressure member 48 and the front cover 34 is compressed to increase the back pressure ((P _TCin + P _TCout ) / 2). The present invention can be applied to a torque converter 20 other than that, for example, a two-port torque converter which is not _{affected by the} back pressure ((P _TCin + P _TCout ) / 2).

  In the above embodiment, the torque converter 20 is used for the vehicle 10. However, instead of the torque converter 20, a fluid power transmission (a fluid coupling) without a torque amplification function may be used. .

  Note that what has been described above is merely 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 (power transmission device for vehicle)
20: Torque converter (fluid transmission)
20p: Pump impeller (input member)
20t: Turbine impeller (output member)
32: Lock-up clutch 56: Electronic control unit (control unit)
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: Transfer control execution part 90g: Differential rotation control execution part 96: Transfer control end condition satisfaction determination part A: Predetermined value P _END : Stroke end pressure P _SLU : Lock-up 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 comprising a fluid power transmission device capable of directly connecting an input member and an output member by engagement of a lockup clutch,
And a flex lockup control unit that controls an engagement pressure of the lockup clutch so that the lockup clutch slips at a predetermined differential rotation.
The flex lock-up control unit is configured to perform pack packing control to pack pack clearances of the lock-up clutch quickly, and the lock-up clutch so that actual differential rotation of the lock-up clutch coincides with preset target differential rotation. To execute differential rotation control for controlling the engagement pressure of the motor, and takeover control for taking over to the differential rotation control by increasing the engagement pressure from the end of the packing control,
The handover control is
The pressure increase control is started to increase the engagement pressure of the lockup clutch with the end of the packing control.
The state in which 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 longer, or the engagement pressure of the lockup clutch is reduced in the pack clearance A vehicle characterized in that the pressure increase control is terminated and the differential rotation control is started when a predetermined pressure or more is higher than a stroke end pressure and a preset second time has elapsed from the start of the pressure increase control. Control device for power transmission equipment.

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