JP5104092B2 - Shift control device for automatic transmission - Google Patents

Description

  The present invention relates to a shift control device for an automatic transmission, and more particularly to an improvement in shift control when a downshift determination is made due to an increase in a driver's required output amount during upshift control.

An automatic transmission that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement devices is widely used in automobiles and the like. In such an automatic transmission, during the upshift control in which the input shaft rotational speed is reduced by supplying hydraulic oil to the first friction engagement device and engaging it, an increase in the driver's output request amount ( For example, when a downshift determination is made in a power-on state (vehicle driving state) due to, for example, a further depression of an accelerator pedal, the first friction engagement device is configured so that the input shaft rotational speed increases with a predetermined change. After the hydraulic pressure of the first friction engagement device is feedback-controlled, the hydraulic fluid of the first friction engagement device may be drained and released, and the hydraulic fluid may be supplied to and engaged with the second friction engagement device to downshift. . In that case, depending on the degree of progress of the upshift control, there is a possibility that a shift shock may occur due to the timing of the release of the first friction engagement device or the engagement of the second friction engagement device. It is considered to wait until it is determined that the process proceeds sufficiently and the downshift control can be appropriately performed, and then switch from the upshift control to the downshift control (see, for example, Patent Document 1).
JP 2001-124193 A

  However, if the upshift control is continued as described above and the start of the downshift control is delayed, the input shaft rotational speed and the rotational speed of the prime mover are reduced as the upshift progresses, so an increase in driving force is desired. There is a possibility that the driver may feel uncomfortable, and there is a problem that the response to the output request (acceleration response, etc.) is deteriorated. In other words, the downshift in the power-on state is performed when the driver desires a quick increase in driving force, such as when the driver's output demand increases, so even if the ride comfort becomes somewhat worse due to a shift shock or the like, It may be desirable to perform a downshift promptly to increase the driving force.

  On the other hand, when the shift from the upshift control to the downshift control is immediately performed according to the downshift determination and the hydraulic pressure of the first friction engagement device is feedback controlled so that the input shaft rotational speed increases with a predetermined change, the torque of the prime mover If the input shaft rotation speed does not increase even if the hydraulic pressure is lowered due to the response delay of the start-up of the engine, the hydraulic pressure is further reduced by feedback control and is reduced more than necessary. The input shaft rotation speed cannot be controlled due to the response delay of the engine, and the prime mover may blow up, causing a shift shock exceeding the allowable limit. In this specification, the fact that the hydraulic pressure is lowered more than necessary by feedback control is hereinafter referred to as feedback control malfunction.

  FIG. 10 shows a case where the accelerator operation amount Acc is increased by the accelerator depressing step during the 3 → 4 upshift control and the 4 → 2 downshift determination is made, and the downshift control is immediately started. When feedback control of the hydraulic pressure command value 1 of the first friction engagement device is performed so that the input shaft rotational speed (NT) increases at a predetermined rate of change, the hydraulic pressure command value 1 becomes a white arrow due to a delay in response to the actual rise of the motor torque. When the prime mover torque increases after that, the turbine rotational speed NT rapidly rises and blows up as indicated by the white arrow due to a delay in response of the hydraulic control.

  The present invention has been made in the background of the above circumstances, and the object of the present invention is to perform a shift shock due to a blow-up of a prime mover or the like when a downshift determination is made in a power-on state during upshift control. It is to improve the response to the driver's output request by promptly starting downshift control while suppressing.

In order to achieve such an object, the first invention provides a downshift determination in a power-on state during upshift control that reduces the input shaft rotation speed by supplying hydraulic oil to the first friction engagement device and engaging it. Is performed, feedback control of the hydraulic pressure of the first friction engagement device is performed so that the input shaft rotation speed increases with a predetermined change, and then the hydraulic oil of the first friction engagement device is drained. In a shift control device for an automatic transmission that performs a downshift by supplying hydraulic oil to and engaging with a second friction engagement device, (a) when the downshift determination is made, the up the shift control immediately stop maintaining the hydraulic pressure of the first frictional engagement device for the stop time of the hydraulic or with gradually decreasing from the hydraulic oil pressure of the of the first frictional engagement device Fidoba While waiting for a predetermined feedback start condition that is estimated to be able to be performed properly, the feedback control is started immediately . (B) The feedback control is a change in the input shaft rotational speed. The hydraulic pressure is controlled so that the rate matches a predetermined target value. (C) The feedback start condition is that an elapsed time after the downshift determination is made is a predetermined time. It is characterized by reaching .

According to a second aspect of the present invention, in the shift control device for an automatic transmission according to the first aspect, the feedback start condition is that the elapsed time after the downshift determination is made reaches the predetermined time, and the input shaft The rate of change of the rotational speed reaches a predetermined value, and the feedback control is started when any one of them is satisfied .

According to a third aspect of the present invention, in the shift control device for an automatic transmission according to the first aspect, the feedback start condition is that the elapsed time after the downshift determination is made reaches the predetermined time, and the motor torque The estimated value has reached a predetermined value determined according to the driver's output request amount, and the feedback control is started when any one of them is satisfied .

In such a shift control device for an automatic transmission, when a downshift determination is made in a power-on state during upshift control, the upshift control is immediately stopped and the hydraulic pressure of the first friction engagement device is reduced. Maintaining or decreasing gradually from the hydraulic pressure at the time of suspension, and immediately waiting for a predetermined feedback start condition that is estimated to be possible to appropriately perform feedback control for downshifting. As a result, the downshift is started more quickly than when the control start (shift output) is delayed in order to ensure the controllability of the downshift. When a downshift decision is made, the discomfort caused by the upshift progress is resolved and the response to the output request There is improved.

In addition, since the feedback control of the hydraulic pressure of the first friction engagement device is started after a predetermined feedback start condition estimated that the feedback control can be appropriately performed is satisfied, a response to the rising of the torque of the prime mover Regardless of the delay, the feedback control of the hydraulic pressure can be appropriately performed so that the rate of change of the input shaft rotation speed matches the predetermined target value, and the shift shock such as the engine blow-up is suppressed. Downshifts can be performed as quickly as possible. That is, if feedback control of the hydraulic pressure of the first friction engagement device is started before the torque of the prime mover rises, the input shaft rotation speed does not increase even if the hydraulic pressure decreases, so that the hydraulic pressure becomes low due to malfunction of the feedback control. However, when the engine torque increases after that, the control of the input shaft rotation speed becomes impossible due to a delay in response of the hydraulic control, and there is a possibility that a large shift shock may occur due to the engine blowing up. Since the feedback control is started after a predetermined feedback start condition that is estimated to be able to be appropriately performed is satisfied, such malfunction of the feedback control can be avoided.

In addition, since the feedback control of the hydraulic pressure of the first friction engagement device is started after a predetermined time has elapsed after the downshift determination is made, the predetermined torque is considered in consideration of the rising characteristic of the motor torque. By appropriately setting the time, it is possible to perform a downshift as quickly as possible while suppressing a shift shock such as a blow-up of a prime mover due to a malfunction of feedback control.

In the second invention, as a feedback start condition, the elapsed time after the downshift determination is made reaches a predetermined time, and the rate of change of the input shaft rotation speed reaches a predetermined value. Then, feedback control is started when either is established. That is, even when the input shaft rotation speed change rate reaches a predetermined value, to initiate the oil pressure of the feedback control of the first friction engagement device, the input shaft rotational speed rises engine torque is increased The feedback control will be started reliably when it starts, and not only when downshift determination is made by downshift command by driver's manual operation but also by downshift determination by increase of driver's output request amount, etc. Also in the downshift determination, the feedback control of the hydraulic pressure of the first friction engagement device is appropriately performed, and the downshift can be promptly performed while suppressing a shift shock such as blowing up of the prime mover.

In the third aspect of the invention, as the feedback start condition, in addition to the elapsed time after the downshift determination is made reaching a predetermined time, the estimated torque value of the prime mover is a predetermined value determined according to the driver's output request amount. The feedback control is started when either of them is satisfied. That is, even if the torque estimate of the engine has reached a predetermined value determined according to the amount of output required by a driver, for starting the oil pressure of the feedback control of the first friction engagement device, ensuring Once it started rising engine torque Feedback control is started, and any downshift decision is made, such as when a downshift decision is made not only by a downshift decision due to an increase in the driver's output request amount but also by a downshift command by the driver's manual operation In this case, the feedback control of the hydraulic pressure of the first friction engagement device is appropriately performed, and the downshift can be performed promptly while suppressing a shift shock such as blowing up of the prime mover.

  The present invention is suitably applied to an automatic transmission for a vehicle, and is an engine-driven vehicle that generates a driving force by combustion of fuel, an electric vehicle that runs by an electric motor, or a hybrid that includes an engine and an electric motor as a prime mover. The present invention can be applied to various vehicle automatic transmissions such as vehicles. In particular, the present invention is suitably applied to an engine-driven vehicle or the like that includes, as a prime mover, an engine or the like that has poor torque rising response to an increase in the driver's output request amount.

  As the automatic transmission, for example, various automatic transmissions such as a planetary gear type and a parallel shaft type in which a plurality of gear stages are established according to the operating states of the plurality of friction engagement devices are used. The friction engagement device is a hydraulic type, for example, by changing the hydraulic pressure (engagement force) with a predetermined change pattern or by changing the hydraulic pressure at a predetermined timing by the hydraulic control by a solenoid valve or the like or the action of an accumulator. Control is performed. These friction engagement devices are single-plate or multi-plate clutches and brakes, belt-type brakes, and the like that are engaged by an actuator such as a hydraulic cylinder.

  The present invention relates to a multiple shift that shifts from midway through upshift control to downshift control. In particular, the first friction engagement device that is engaged halfway through upshift control is associated with the shift to downshift control. The present invention relates to a technique for releasing as quickly as possible while suppressing shift shock. These up-shifts and down-shifts may be a shift between successive gear stages, or may be a jump shift that shifts over one or more gear stages.

  The upshift that engages the first friction engagement device is, for example, a power that reduces the input shaft rotation speed by the engagement torque of the first friction engagement device in the power ON state (vehicle drive state) output by the prime mover. The present invention is preferably applied when the downshift determination is made during the inertia phase in which the input shaft rotation speed decreases due to the engagement torque of the first friction engagement device in the ON upshift. Further, this upshift is performed automatically, for example, as the vehicle speed increases in accordance with a predetermined shift condition using the driver's output request amount (accelerator operation amount, etc.) and the driving state such as the vehicle speed as parameters. Alternatively, it may be performed in accordance with an upshift command manually operated by the driver, such as a shift lever operation.

  The determination of the downshift in the power ON state, that is, the vehicle driving state, is performed based on, for example, a driver's output request amount based on a predetermined shift condition so as to shift down with an increase in output request amount (accelerator operation amount, etc.) However, it may be performed in accordance with a downshift command manually operated by the driver such as a shift lever operation. The power ON state is a driving state in which power is transmitted from the prime mover to the driving wheel side, and is a state in which the input shaft rotational speed increases when the automatic transmission is in the neutral state. For example, the engine rotational speed is the turbine of the torque converter. When the speed is higher than the rotation speed, it can be determined that the power is on. However, when the accelerator is operated, there is a high possibility that the power is on. Therefore, when the accelerator is operated, the power is on. It can be tricked.

In such a downshift in the power-on state, the rate of change of the input shaft rotation speed matches a predetermined target value so that the downshift is performed quickly while preventing the prime mover from blowing up. Thus, the hydraulic pressure (engagement force) of the first friction engagement device is feedback-controlled as described above. However, if the feedback control is started before the torque of the prime mover rises, the input shaft rotation speed will be increased even if the hydraulic pressure decreases. Since the oil pressure does not increase, the hydraulic pressure becomes too low due to a malfunction of the feedback control, and a shift shock or the like is caused by the subsequent increase in the motor torque. The hydraulic pressure feedback control of the engagement device is started.

The feedback start condition is determined based on the response of the torque rise of the prime mover, the torque characteristics, or the actual change in the input shaft rotational speed. Specifically, the feedback control is started after a predetermined time elapses after the downshift determination is made. This predetermined time is based on the torque rise response of the prime mover, torque characteristics, etc. A predetermined value may be determined in advance, or may be set on a map or the like using, for example, the driver's output request amount, the type of downshift, the current input shaft rotation speed, the motor rotation speed, and the like as parameters. .

The plant constant time, for example, assuming the case where automatic downshift determination based on a predetermined shift condition when the increase in the amount of output required by the driver is made, based on the rising response and the like of the torque of the prime mover This is used together with the determination based on the change rate of the input shaft rotational speed of the second invention and the determination based on the torque estimation value of the prime mover of the third invention, which function effectively other than the downshift determination due to the increase in the driver's output request amount. It is desirable.

In the second invention, the feedback control is started after the rate of change of the actual input shaft rotation speed reaches a predetermined value, which is a predetermined value based on the torque characteristics of the prime mover. For example, the output request amount of the driver, the type of downshift, the current input shaft rotational speed, the prime mover rotational speed, the degree of progress of the upshift, etc. are set on a map or the like as parameters. Also good. When the first invention is implemented, the feedback start condition may be that the rate of change of the rotational speed of the prime mover reaches a predetermined value.

In the third aspect of the invention, the feedback control is started after the estimated torque value of the prime mover reaches a predetermined value determined in accordance with the driver's requested output amount. The input shaft rotation speed, the prime mover rotation speed, and the like may be set on a map or the like as parameters. Further, when the feedback control is started after the estimated value of the input torque (estimated input torque) that changes according to the torque of the prime mover reaches a predetermined value, the feedback is substantially based on the estimated torque value of the prime mover. It is one embodiment of the 3rd invention which starts control.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a skeleton diagram of a horizontally mounted vehicle drive device such as an FF (front engine / front drive) vehicle. The output of an engine 10 constituted by an internal combustion engine such as a gasoline engine or a diesel engine is torque Via a converter 12 and an automatic transmission 14, a differential gear device (not shown) is transmitted to drive wheels (front wheels). The engine 10 is a power source (prime mover) for traveling the vehicle, and the torque converter 12 is a fluid coupling.

  The automatic transmission 14 includes a first transmission unit 22 mainly composed of a single pinion type first planetary gear unit 20, a single pinion type second planetary gear unit 26, and a double pinion type third planetary gear unit. The second transmission unit 30, which is mainly composed of 28, is provided on the coaxial line, and the rotation of the input shaft 32 is shifted and output from the output gear 34. The input shaft 32 corresponds to the input member, and in this embodiment is the turbine shaft of the torque converter 12, and the output gear 34 corresponds to the output member, and rotates the left and right drive wheels via the differential gear device. To drive. The automatic transmission 14 is substantially symmetrical with respect to the center line, and the lower half of the center line is omitted in FIG.

  The first planetary gear unit 20 constituting the first transmission unit 22 includes three rotation elements, that is, a sun gear S1, a carrier CA1, and a ring gear R1, and the sun gear S1 is connected to the input shaft 32 to be rotationally driven. At the same time, the ring gear R1 is fixed to the case 36 through the third brake B3 so as not to rotate, whereby the carrier CA1 is decelerated and rotated with respect to the input shaft 32 as an intermediate output member. Further, the second planetary gear device 26 and the third planetary gear device 28 constituting the second transmission unit 30 are partially connected to each other to constitute four rotating elements RM1 to RM4. Specifically, the first rotating element RM1 is constituted by the sun gear S3 of the third planetary gear device 28, and the ring gear R2 of the second planetary gear device 26 and the ring gear R3 of the third planetary gear device 28 are connected to each other to perform the second rotation. The element RM2 is configured, and the carrier CA2 of the second planetary gear unit 26 and the carrier CA3 of the third planetary gear unit 28 are coupled to each other to configure the third rotating element RM3. A four-rotation element RM4 is configured. In the second planetary gear device 26 and the third planetary gear device 28, the carriers CA2 and CA3 are constituted by a common member, the ring gears R2 and R3 are constituted by a common member, and the second The pinion gear of the planetary gear device 26 is a Ravigneaux type planetary gear train that also serves as the second pinion gear of the third planetary gear device 28.

  The first rotating element RM1 (sun gear S3) is selectively connected to the case 36 by the first brake B1 and stopped rotating, and the second rotating element RM2 (ring gears R2, R3) is selectively selected by the second brake B2. The fourth rotation element RM4 (sun gear S2) is selectively connected to the input shaft 32 via the first clutch C1, and the second rotation element RM2 (ring gears R2, R3) is connected to the case 36 and stopped. Is selectively coupled to the input shaft 32 via the second clutch C2, and the first rotating element RM1 (sun gear S3) is integrally coupled to the carrier CA1 of the first planetary gear device 20 as an intermediate output member, The third rotation element RM3 (carriers CA2, CA3) is integrally connected to the output gear 34 to output rotation.

The clutches C1, C2 and the brakes B1, B2, B3 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are hydraulic friction members that are engaged and controlled by a hydraulic actuator such as a multi-plate clutch or a band brake. 2 is engaged and released as shown in FIG. 2 by switching the hydraulic circuit by excitation or non-excitation of the linear solenoid valves SL1 to SL5 of the hydraulic control circuit 98 (see FIG. 3) or a manual valve (not shown). The state is switched, and the six forward gears and the reverse one gear are established according to the operation position (position) of the shift lever 72 (see FIG. 3). “1st” to “6th” in FIG. 2 mean the first to sixth gears for forward travel, and “Rev” is the reverse gear for the gear ratio (= input shaft rotation). (Speed N _IN / output shaft rotational speed N _OUT ) is appropriately determined by the gear ratios ρ1, ρ2, and ρ3 of the first planetary gear device 20, the second planetary gear device 26, and the third planetary gear device 28. “◯” in FIG. 2 means engagement, and a blank means release.

  The shift lever 72 is, for example, in accordance with the shift pattern shown in FIG. 4, a parking position “P”, a reverse travel position “R”, a neutral position “N”, a forward travel position “D”, “4”, “3”, “2” ”And“ L ”, and in the“ P ”and“ N ”positions, neutral is established to cut off the power transmission. However, in the“ P ”position, a mechanical parking mechanism (not shown) is used to mechanically The rotation of the drive wheel is prevented.

FIG. 3 is a block diagram illustrating a control system provided in the vehicle for controlling the engine 10, the automatic transmission 14, and the like. The operation amount (accelerator opening) Acc of the accelerator pedal 50 is an accelerator operation amount sensor 51. Is to be detected. The accelerator pedal 50 is largely depressed according to the driver's requested output amount, and corresponds to an accelerator operation member, and the accelerator operation amount Acc corresponds to the requested output amount. In addition, an electronic throttle valve 56 whose opening degree θ _TH is changed by a throttle actuator 54 is provided in the intake pipe of the engine 10. In addition, an intake air amount sensor 60 for detecting an intake air quantity Q of the engine rotational speed sensor 58, the engine 10 for detecting the rotational speed NE of the engine 10, the intake for detecting the temperature T _A of intake air The air temperature sensor 62, the throttle valve 64 with an idle switch for detecting the fully closed state (idle state) of the electronic throttle valve 56 and the opening degree θ _TH, and the rotational speed (output shaft) of the output gear 34 corresponding to the vehicle speed V a vehicle speed sensor 66 for detecting the corresponding) N _OUT of the rotational speed, the cooling water temperature sensor 68 for detecting the cooling water temperature T _W of the engine 10, a brake switch 70 for detecting the presence or absence of foot brake operation, the shift lever 72 Lever position sensor 74 for detecting the lever position (operation position) _PSH of the turbine, and detecting the turbine rotation speed NT Are provided with a turbine rotation speed sensor 76, an AT oil temperature sensor 78 for detecting an AT oil temperature T _OIL that is the temperature of the hydraulic oil in the hydraulic control circuit 98, an ignition switch 82, and the like. , Engine speed NE, intake air amount Q, intake air temperature T _A , throttle valve opening θ _TH , vehicle speed V (output shaft rotation speed N _OUT ), engine coolant temperature T _W , presence / absence of brake operation, shift lever 72 A signal representing the lever position P _SH , turbine rotational speed NT, AT oil temperature T _OIL , operation position of the ignition switch 82, etc. is supplied to the electronic control unit 90. The turbine rotational speed NT is the same as the rotational speed of the input shaft 32 (input shaft rotational speed N _IN ) that is an input member.

The hydraulic control circuit 98 includes a circuit shown in FIG. 5 regarding the shift control of the automatic transmission 14. In FIG. 5, the hydraulic oil pumped from the oil pump 40 is adjusted to a first line pressure PL <b> 1 by being regulated by a relief type first pressure regulating valve 100. The oil pump 40 is, for example, a mechanical pump that is rotationally driven by the engine 10. The first pressure regulating valve 100 regulates the first line pressure PL1 according to the turbine torque T _T, that is, the input torque T _IN of the automatic transmission 14, or the throttle valve opening θ _TH that is a substitute value thereof. The one-line pressure PL1 is supplied to the manual valve 104 that is interlocked with the shift lever 72. Then, when the shift lever 72 is operated to the forward drive position such as "D" position is a forward position pressure P _D of the same size from the manual valve 104 and the first line pressure PL1 is the linear solenoid valve SL1~SL5 Supplied. The linear solenoid valves SL1 to SL5 are arranged corresponding to the clutches C1 and C2 and the brakes B1 to B3, respectively, and the excitation state is controlled according to the drive signal output from the electronic control unit 90, respectively. The engagement hydraulic pressures P _C1 , P _C2 , P _B1 , P _B2 , and P _B3 are independently controlled, so that any one of the first speed gear stage “1st” to the sixth speed gear stage “6th” is controlled. Alternatively, it can be established. The linear solenoid valves SL1 to SL5 are all of a large capacity type, and the output hydraulic pressure is supplied to the clutches C1 and C2 and the brakes B1 to B3 as they are, and their engagement hydraulic pressures P _C1 , P _C2 , P _B1 , P _B2 , P Direct pressure control that directly controls _B3 is performed.

  The electronic control unit 90 includes 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. By performing signal processing, the respective functions of the engine control means 120 and the shift control means 130 are executed as shown in FIG. 6, and are configured separately for engine control and shift control as required. Is done.

The engine control means 120 controls the output of the engine 10, and controls the fuel injection valve 92 (see FIG. 3) for controlling the fuel injection amount in addition to controlling the opening and closing of the electronic throttle valve 56 by the throttle actuator 54. The ignition device 94 such as an igniter is controlled for ignition timing control. Control of the electronic throttle valve 56, for example, drives the throttle actuator 54 based on the actual accelerator operation amount Acc from the relationship shown in FIG. 7, the accelerator operation amount Acc increases the throttle valve opening theta _TH enough to increase. Further, when the engine 10 is started, cranking is performed by a starter (electric motor) 96.

The shift control means 130 performs shift control of the automatic transmission 14, and is automatically performed based on the actual throttle valve opening _θTH and the vehicle speed V from a previously stored shift diagram (shift map) shown in FIG. The gear stage to which the transmission 14 is to be shifted is determined, that is, the shift determination from the current gear stage to the shift destination gear stage is executed, and the shift output for starting the shift operation to the determined gear stage is executed. In addition, the excitation states of the linear solenoid valves SL1 to SL5 of the hydraulic control circuit 98 are set so that a shift shock such as a change in driving force does not occur and the durability of the friction material of the clutch C and the brake B is not impaired. Change continuously. As is apparent from FIG. 2, the automatic transmission 14 according to this embodiment is configured so that a continuous gear is released by a clutch-to-clutch shift in which one of the clutch C and the brake B is released and the other is engaged. Shifting of gears is performed. The solid line in FIG. 8 is an upshift line, and the broken line is a downshift line so that as the vehicle speed V decreases or the throttle valve opening _θTH increases, the gear position on the low speed side with a large gear ratio can be switched. In the figure, “1” to “6” mean the first speed gear stage “1st” to the sixth speed gear stage “6th”. Since the throttle valve opening θ _TH is controlled in accordance with the accelerator operation amount Acc, the throttle valve opening θ _TH is determined to correspond to the driver's output request amount and to be downshifted as the output request amount increases.

  When the shift lever 72 is operated to the “D” position, the uppermost D range (automatic shift mode) that automatically shifts using all the forward gears “1st” to “6th” is established. It is done. Further, when the shift lever 72 is operated to the “4” to “L” position, the respective shift ranges of 4, 3, 2, and L are established. In the 4th range, the shift control is performed at the forward gear stage below the 4th speed gear stage “4th”, the shift control is performed at the forward gear stage below the 3rd speed gear stage “3rd” in the 3rd range, and the shift control is carried out at the 2nd range. The speed change control is performed at the forward gear stage below the second gear stage “2nd”, and is fixed at the first gear stage “1st” in the L range. Therefore, for example, if the shift lever 72 is operated from the “D” position to the “4” position, the “3” position, or the “2” position while traveling at the sixth speed gear stage “6th” of the D range, the shift range becomes D. 4 → 3 → 2 forcibly switched from sixth gear stage “6th” to fourth gear stage “4th”, third gear stage “3rd”, second gear stage “2nd” It is downshifted and the gear stage can be changed manually.

The shift control means 130 is also provided with an up-down multiple shift means 132 at power-on, and when a downshift determination is made during upshift control in the power-on state, the multiple shift according to the flowchart of FIG. Execute control. FIG. 10 shows that the third speed gear stage “3rd” to the fourth speed gear stage “in accordance with an increase in the vehicle speed V (for example, A → B in FIG. 8) in the power ON state (vehicle driving state) where the accelerator pedal 50 is depressed. 4th "is determined (time t ₁ ), and the third brake B3 is released and the second clutch C2 is engaged and the 3 → 4 upshift control (first shift control) is being executed. Further, during the shift control, the accelerator pedal 50 is further increased (for example, B → C in FIG. 8), and the downshift determination from the fourth speed gear stage “4th” to the second speed gear stage “2nd” is made. When this is done (time t ₃ ), multiple shift control is performed according to the flowchart of FIG. 9 to release the second clutch C2 and engage the first brake B1 (4 → 2 downshift control (second shift). control) It is an example of a time chart showing changes in respective portions when done. In this case, the second clutch C2 is engaged by the first shift (3 → 4 upshift) and released by the second shift (4 → 2 downshift), and the hydraulic command The value 1 is a command value relating to the engagement oil pressure P _C2 of the first friction engagement device, that is, the second clutch C2. Further, the first brake B1 is a second friction engagement device that is engaged by a second speed change (4 → 2 downshift), and the hydraulic pressure command value 2 is an engagement of the second friction engagement device, that is, the first brake B1. This is a command value related to the combined hydraulic pressure P _B1 . This such as a hydraulic command value 1, the hydraulic pressure command value 2 are both correspond to the engagement pressure P _C2, P _B1, the hydraulic pressure command value 1, the engagement pressure P _C2 accordance hydraulic pressure command value 2 is high, P _B1 also The actual engagement oil pressures P _C2 and P _B1 change later and later than the oil pressure command values 1 and 2, although they become higher. In addition, although illustration is omitted, in the 3 → 4 upshift, the engagement hydraulic pressure P _B3 of the third brake _B3 is gradually reduced and released promptly with the start of the inertia phase.

Hereinafter, the case of the multiple shift of 3 → 4 → 2 will be specifically described according to the flowchart of FIG. 9 with reference to the time chart of FIG. In step S1, the turbine rotational speed NT is set at a predetermined rate of change by determining whether or not the 3 → 4 upshift control in the power ON state is being performed, that is, by releasing the third brake B3 and engaging the second clutch C2. It is determined whether or not the 3 → 4 upshift control to be reduced is being executed. If it is being executed, step S2 and subsequent steps are executed. Whether the power is on or not can be determined, for example, based on whether or not the engine speed NE is higher than the turbine speed NT, depending on whether the accelerator pedal 50 is depressed and the accelerator operation amount Acc. Even when the electronic throttle valve 56 to be controlled is not in the idle state, it is highly possible that the electronic throttle valve 56 is in the power-on state. Therefore, whether the electronic throttle valve 56 is in the power-on state depends on whether the accelerator is on or not. It can also be determined whether or not. Further, it does not matter whether the upshift is based on the automatic shift control based on the shift map shown in FIG. 8 or the manual shift based on the movement operation of the shift lever 72, but it may be limited to the automatic shift control. The time t _{1 in} FIG. 10 is the time when the power ON 3 → 4 upshift determination is made and the upshift control is started. After this time t ₁ , the determination in step S1 is YES (positive) and the step S2 is executed.

In step S2, in the 3 → 4 upshift control, it is determined whether or not the inertia phase in which the turbine rotational speed NT is lower than the synchronous rotational speed ntdoki3 of the third gear stage “3rd” due to the engagement of the second clutch C2. When the inertia phase starts, step S3 and subsequent steps are executed. Synchronous speed Ntdoki3 is a value obtained by multiplying the output shaft speed N _OUT to the gear ratio of the third speed gear position "3rd", when the third-speed gear position "3rd" is established in the NT = ntdoki3 Yes, when gear shifting starts (inertia phase), NT ≠ ntdoki3. Time t ₂ in FIG. 10 is a time start determination of the inertia phase is made, this time t ₂ subsequent step S3 the determination in step S2 is a YES (affirmative) is executed. Note that “ntdoki2” and “ntdoki4” in FIG. 10 are the synchronous rotational speed of the second gear stage “2nd” and the synchronous rotational speed of the fourth gear stage “4th”, respectively.

In step S3, it is determined whether or not a downshift determination has been made in the power-on state. If a power-on downshift determination has been made, step S4 and subsequent steps are executed. Whether or not the power is on can be determined in the same manner as in the case of determining whether or not the power is on based on the determination of the power on upshift in step S1. Here, it does not matter whether the downshift is determined by the automatic shift control based on the shift map of FIG. 8 or the downshift is determined by the manual shift based on the movement operation of the shift lever 72, but only in the case of the automatic shift control. Also good. Further, it may be determined whether or not the downshift is determined by stepping on the accelerator pedal 50 based on a change in the accelerator operation amount Acc or the like, and step S4 and subsequent steps may be executed only when the downshift is determined by increasing stepping. FIG. 10 shows that when the accelerator pedal 50 is further depressed and the accelerator operation amount Acc is suddenly increased, the jump from the fourth gear stage “4th” to the second gear stage “2nd” is performed according to the shift map of FIG. Even in the case of shifting, when downshifting only one step from the fourth speed gear stage “4th” to the third speed gear stage “3rd”, step S4 and subsequent steps are executed and the same control is performed. The time t _{3 in} FIG. 10 is the time when the power ON 4 → 2 downshift determination is made and the determination in step S3 is YES (positive).

  In step S4, the 3 → 4 upshift control is immediately stopped. That is, the feedback control of the hydraulic pressure command value 1 that lowers the turbine rotational speed NT at a predetermined rate of change in order to engage the second clutch C2 is stopped. In step S5, feed-forward control is performed so that the oil pressure command value 1 of the friction engagement device to be released by the 4 → 2 downshift, that is, the second clutch C2 is changed at a predetermined change rate. In this feedforward control, the hydraulic pressure command value 1 may be gradually decreased at a predetermined constant rate of change, but the progress of the 3 → 4 upshift, for example, the actual difference with respect to the difference between the synchronous rotational speeds ntdoki3 and ntdoki4 The rate of change may be set according to the change rate [(ntdoki3-NT) / (ntdoki3-ntdoki4)] of the turbine rotation speed NT. Note that the hydraulic pressure command value 1 may be fixed to the value at the start of control, that is, when the feedback control is stopped in step S4, without performing such feedforward control.

Then, in the next step S6, whether or not the elapsed time after the 4 → 2 downshift determination is made in step S3, that is, the time elapsed from the time t ₃ in FIG. 10 has reached a predetermined time TimeA, or indeed It is determined whether or not the rate of change ΔNT of the turbine rotation speed NT has reached a predetermined determination value dntA. If any of them is satisfied, feedback control of the release hydraulic pressure, that is, the hydraulic pressure command value 1 is started in step S7. Step S6 temporarily prohibits the start of the feedback control until the torque of the engine 10 starts to increase in response to the increased depression of the accelerator pedal 50 in order to appropriately perform the feedback control of Step S7. Thus, the YES (affirmative) condition in step S6 is a feedback start condition that is estimated that the feedback control in step S7 can be appropriately performed.

That is, in step S7, the second clutch C2 is engaged so that the rate of change ΔNT of the turbine rotational speed NT coincides with the predetermined target value dntB so that the downshift is performed quickly while preventing the engine 10 from blowing up. Although the hydraulic pressure command value 1 related to the hydraulic pressure P _C2 is feedback controlled, if the feedback control is started before the torque of the engine 10 rises, the turbine rotational speed NT does not increase even if the engagement hydraulic pressure P _C2 decreases. The hydraulic pressure command value 1 greatly decreases as indicated by the white arrow in FIG. 10 due to a malfunction of the control, and when the engine torque starts to increase thereafter, the turbine rotational speed NT is appropriately controlled by a response delay of the hydraulic control or the like. May not be possible, and as shown by the white arrow in FIG. That.

  In order to avoid such a problem and the 4 → 2 downshift is executed as quickly as possible, in step S6, the elapsed time after the 4 → 2 downshift determination is reached the predetermined time timeA. Whether or not the feedback start condition is satisfied is determined based on whether or not the change rate ΔNT of the turbine rotation speed NT has reached a predetermined determination value dntA. The predetermined time timeA is preliminarily set based on the rising response of the torque of the engine 10 on the assumption that the accelerator pedal 50 is increased, and for example, a predetermined value is set in advance. The type of shift (from which gear stage to which gear stage), turbine rotational speed NT, engine rotational speed NE, or the like may be set on a map or the like as parameters. Further, the determination value dntA is set to a predetermined value in advance based on, for example, the rising characteristic of the torque of the engine 10 so that the feedback control in step S7 is appropriately started regardless of the response delay of the hydraulic control. The accelerator operation amount Acc, the type of downshift, the turbine rotational speed NT, the engine rotational speed NE, or the degree of progress of the 3 → 4 upshift may be set as a parameter on a map or the like.

If the feedback start condition in step S6 is satisfied, step S7 is executed, and the engagement hydraulic pressure of the second clutch C2 is set so that the rate of change ΔNT of the turbine rotational speed NT matches the predetermined target value dntB. starts feedback control of the hydraulic pressure command value 1 regarding P _C2. The target value dntB is, for example, a constant value set in advance so that the downshift can be performed as quickly as possible while suppressing the shift shock. However, the target value dntB is set to the accelerator operation amount Acc, the type of dow syft, and the synchronous rotational speed of the gear stage after the shift. It may be set by a map or the like using the increase width of the turbine rotation speed NT until the value reaches as a parameter. As described above, the feedback control in step S7 is started after the feedback start condition in step S6 is satisfied, so that the rate of change ΔNT of the turbine rotational speed NT is set to a predetermined value regardless of the response delay of the rising of the torque of the engine 10. The feedback control of the hydraulic pressure command value 1 is appropriately performed so as to coincide with the target value dntB. Time t _{4 in} FIG. 10 is the time when the determination in step S6 is YES (positive) and the feedback control in step S7 is started.

Note that the hydraulic pressure command value 2 relating to the engagement hydraulic pressure P _B1 of the first brake B1 that is controlled to be engaged by the second shift 4 → 2 downshift is the hydraulic control immediately after the 4 → 2 downshift determination is made. Is started and the first brake B1 is held at the low pressure standby pressure immediately before having the engagement torque after the first fill, while the turbine rotational speed NT exceeds or reaches the synchronous rotational speed ntdoki2 after the shift ( At time t ₅ ), the hydraulic pressure command value 2 is increased and the first brake B1 is engaged, so that the turbine rotational speed NT is overshot by a predetermined amount and converged to the synchronous rotational speed ntdoki2. When the first brake B1 has an engagement torque, the hydraulic pressure command value 1 relating to the engagement hydraulic pressure P _C2 of the second clutch C2 is decreased, and the hydraulic oil of the second clutch C2 is drained and released quickly. Then, at time t ₆ when the hydraulic pressure command value 1 becomes 0 and the hydraulic pressure command value 2 becomes the maximum value, the series of multiple shift control ends.

  As described above, in the shift control device for the automatic transmission for a vehicle according to the present embodiment, when the downshift determination is made during the upshift control in the power ON state, the upshift control is immediately stopped in step S4. In step S6, it is determined whether or not a predetermined feedback start condition is satisfied. If the feedback start condition is satisfied, feedback control of the hydraulic pressure command value 1 of the disengagement side frictional engagement device is immediately performed in step S7. Therefore, the downshift is started more quickly than when the control start is delayed in order to ensure the controllability of the downshift, and the downshift judgment is made by increasing the accelerator pedal 50. In this case, the uncomfortable feeling due to the progress of the upshift is eliminated and the response to the output request is improved.

  Further, in step S6, it is determined whether or not a feedback start condition estimated that feedback control can be appropriately performed is satisfied, and when it is satisfied, feedback control of the hydraulic pressure command value 1 in step S7 is started. Therefore, it is possible to appropriately perform the feedback control of the hydraulic pressure command value 1 so that the rate of change ΔNT of the turbine rotation speed NT matches the predetermined target value dntB, regardless of the response delay of the torque rise of the engine 10. A downshift can be performed as quickly as possible while suppressing a shift shock such as a blow-up of the engine 10. That is, if feedback control of the hydraulic pressure command value 1 is started before the torque of the engine 10 rises, the turbine rotational speed NT does not increase even if the hydraulic pressure command value 1 is decreased. However, when the engine torque starts to increase after that, the control of the turbine rotational speed NT becomes impossible due to a delay in response of the hydraulic control, and there is a possibility that a large shift shock may occur due to the engine 10 blowing up, In this embodiment, since the feedback control is started after the feedback start condition in step S6 is satisfied, such a problem can be avoided.

  Further, in this embodiment, it is determined whether or not the elapsed time after the downshift determination in step S3 has reached the predetermined time timeA as the feedback start condition, and when the predetermined time timeA is reached, the release is performed in step S7. Feedback control of the hydraulic pressure command value 1 on the side is started, and the predetermined time timeA is based on the rising response of the torque of the engine 10 on the premise that the predetermined time timeA is a downshift due to the additional depression of the accelerator pedal 50. Therefore, it is possible to perform a downshift as quickly as possible while suppressing a shift shock such as a blow-up of the engine 10 due to a malfunction of feedback control.

  Further, in this embodiment, separately from whether or not the elapsed time has reached the predetermined time timeA, it is determined whether or not the rate of change ΔNT of the turbine rotational speed NT has reached a predetermined determination value dntA, and the determination value Even when dntA is reached, since feedback control of the release side hydraulic pressure command value 1 is started in step S7, feedback is surely made when the torque of the engine 10 rises and the turbine rotational speed NT starts to increase. Control is started, and feedback control of the hydraulic pressure command value 1 is performed more appropriately. In particular, feedback control of the hydraulic pressure command value 1 in any downshift determination, such as when a downshift determination is made by a downshift command by a driver's manual operation as well as a downshift determination by increasing the accelerator pedal 50 Is appropriately performed, and a downshift can be promptly performed while suppressing a shift shock such as a blow-up of the engine 10.

  Here, in the above embodiment, in step S6, whether or not the elapsed time after the downshift determination has reached the predetermined time timeA, or the change rate ΔNT of the turbine rotational speed NT reaches the predetermined determination value dntA. However, as shown in FIG. 11, step S6-1 is provided instead of step S6, and the elapsed time after the downshift determination is made is a predetermined time timeA. It is determined whether or not the estimated value of the engine torque has reached a predetermined determination value teA, and if any of them is satisfied, it is determined that the feedback start condition is satisfied, and the feedback control in step S7 May be started. The estimated engine torque value is calculated by a predetermined arithmetic expression or map using, for example, the intake air amount Q of the engine 10 and the engine rotational speed NE as parameters. In addition, the determination value teA is set to a larger value as the accelerator operation amount Acc is larger, using the accelerator operation amount Acc as a parameter so that the feedback control in step S7 is appropriately started regardless of the response delay of the hydraulic control. In addition to the accelerator operation amount Acc, the type of downshift, the turbine rotational speed NT, the engine rotational speed NE, and the like may be set on a map or the like as parameters.

  Also in this case, in step S6-1, it is determined whether or not a predetermined feedback start condition presumed that the feedback control in step S7 can be appropriately performed is satisfied. In order to start the control, the feedback control of the hydraulic pressure command value 1 is appropriately performed so that the rate of change ΔNT of the turbine rotational speed NT matches the predetermined target value dntB, regardless of the response delay of the torque rise of the engine 10. It is possible to obtain the same operational effects as in the previous embodiment.

  Further, it is determined whether or not the estimated engine torque value has reached a predetermined determination value teA, and when the determination value teA is reached, feedback control of the release side hydraulic pressure command value 1 is started in step S7. When the torque of the engine 10 starts to rise, the feedback control is surely started, and the feedback control of the hydraulic pressure command value 1 is appropriately performed. In particular, feedback control of the hydraulic pressure command value 1 in any downshift determination, such as when a downshift determination is made by a downshift command by a driver's manual operation as well as a downshift determination by increasing the accelerator pedal 50 Is appropriately performed, and a downshift can be promptly performed while suppressing a shift shock such as a blow-up of the engine 10.

  Note that the determination as to whether or not the estimated engine torque value performed in step S6-1 has reached a predetermined determination value teA is made in step S6 of FIG. 9, and one of the three feedback start conditions is satisfied. Alternatively, the feedback control in step S7 may be started.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

1 is a skeleton diagram of a vehicle drive device to which the present invention is applied. FIG. 2 is a diagram illustrating engagement and disengagement states of clutches and brakes for establishing each gear stage of the automatic transmission of FIG. 1. It is a figure explaining the input-output signal of the electronic control apparatus provided in the vehicle of the Example of FIG. It is a figure which shows an example of the shift pattern of the shift lever of FIG. FIG. 4 is a circuit diagram illustrating a configuration of a portion related to shift control of the automatic transmission in the hydraulic control circuit of FIG. 3. It is a block diagram explaining the function with which the electronic control apparatus of FIG. 3 is provided. Is a diagram showing an example of a relationship between the accelerator operation amount Acc and the throttle valve opening theta _TH used in the throttle control performed by the engine control unit of FIG. It is a figure which shows an example of the shift map (map) used by the shift control of the automatic transmission performed by the shift control means of FIG. FIG. 7 is a flowchart for specifically explaining the processing contents of an up-down multiple shift means at the time of power ON in FIG. FIG. 10 is an example of a time chart showing changes of each part when signal processing is performed according to the flowchart of FIG. 9 at the time of multiple shift of 3 → 4 → 2. It is a figure explaining the other Example of this invention, and is a flowchart corresponding to FIG.

Explanation of symbols

10: Engine (prime mover) 14: Automatic transmission 90: Electronic control device 132: Up-down multiple transmission means at power ON NT: Turbine rotational speed (input shaft rotational speed) C2: Second clutch (first friction engagement device) B1: First brake (second friction engagement device) P _C2 : Second clutch engagement hydraulic pressure (hydraulic pressure of the first friction engagement device)
Steps S6 and S6-1: Feedback start conditions

Claims (3)

When a downshift determination is made in a power-on state during upshift control in which hydraulic oil is supplied to and engaged with the first friction engagement device to reduce the input shaft rotational speed, the input shaft rotational speed is preliminarily determined. After the feedback control of the hydraulic pressure of the first friction engagement device so as to increase at a predetermined change, the hydraulic oil of the first friction engagement device is drained and released, and the hydraulic oil is supplied to the second friction engagement device. In a shift control device for an automatic transmission that performs a downshift by supplying and engaging
When the down-shift judgment is made, to cancel the upshift control immediately to maintain the hydraulic pressure of the first frictional engagement device to the hydraulic during the stop, or with gradually decreasing from the hydraulic, the first friction while start immediately the feedback control waits for predetermined feedback starting condition that is estimated to be able to carry out the hydraulic pressure of the feedback control of the engagement devices properly is established,
The feedback control is to control the hydraulic pressure so that the rate of change of the input shaft rotation speed matches a predetermined target value.
The shift control device for an automatic transmission , wherein the feedback start condition is that an elapsed time after the downshift determination is made reaches a predetermined time . Wherein the feedback start condition, in addition to the elapsed time after the downshift determination is made reaches the predetermined time, has to reach a predetermined value by the input shaft rotational speed change rate reaches a predetermined 2. The shift control apparatus for an automatic transmission according to claim 1 , wherein the feedback control is started when either of them is established . In the feedback start condition, in addition to the elapsed time after the downshift determination is made reaching the predetermined time, the estimated torque value of the prime mover reaches a predetermined value determined according to the driver's output request amount. The shift control apparatus for an automatic transmission according to claim 1 , wherein the feedback control is started when any of the conditions is established .

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