JP4687376B2 - Hydraulic control device for automatic transmission for vehicle - Google Patents

Description

  The present invention relates to a hydraulic control device for an automatic transmission for a vehicle that performs a power-off upshift by grasping a friction engagement element during inertial traveling of the vehicle, and more particularly to a disengagement side frictional engagement during a power-off upshift. The present invention relates to a technique for reducing the working hydraulic pressure from the joint element.

  2. Description of the Related Art There is known an automatic transmission for a vehicle in which a power-off upshift is executed by releasing a release-side frictional engagement element and engaging an engagement-side frictional engagement element while the vehicle is coasting. For example, it is described in Patent Document 1. In this Patent Document 1, when an upshift is performed in a power-off state in which the accelerator operating member is released, a release that controls the hydraulic pressure supplied to the release-side frictional engagement element at the time of shifting output of the power-off upshift. A technique is described in which the duty factor of the side solenoid valve is reduced from 100% to 0% at once, and the release side frictional engagement element is quickly released by rapidly reducing (discharging) the hydraulic pressure.

FIG. 17 shows hydraulic pressures of engagement (apply) and release (drain) of the disengagement side frictional engagement element and the engagement side frictional engagement element at the time of power-off upshift in the conventional automatic transmission as described above. It is a figure which shows an example of a control action. 17, time t ₀ time which is the accelerator-off the accelerator operation member is released, t ₁ time speed change output of 3 → 4 power-off upshift (hereinafter, first shift output) start time, t ₄ time Indicates the start point of the shift output of the 4 → 5 power off upshift (hereinafter referred to as the second shift output). Then, at the time of each shift output as shown in these time point t ₁ and t ₄ time, the duty ratio of the release-side solenoid valve is the minimum value MIN for example 0% stretch from the maximum value MAX, for example, 100% release side frictional engagement Drain hydraulic pressure control is performed in which the joint element is released quickly.

In general, there is a response delay in the change of the output torque T _OUT of the automatic transmission with respect to the operation of the accelerator operating member. Therefore, even if the accelerator operating member is released, the output torque T _OUT is not controlled by the accelerator operating member. The power source gradually decreases from a positive value before release to a negative value, and the power source does not immediately change from the driven state to the driven state.

Therefore, the output torque T _OUT does not immediately change to a negative value even when the accelerator is turned off as shown from the time t _{0 to the} time t ₁ , and such output torque T _OUT is a positive value and the power when the source is in the driving state, when the first shift release side friction engagement element with the output at time point t ₁ is released quickly, as described above, the output torque T _oUT is t ₁ time to t _Since it decreases from a positive value toward a negative value as shown at time _{2, the} output torque T _OUT is originally a positive value when the accelerator is turned off even when there is no first shift output. sometimes changes from the negative value, rapid release of the release-side friction engagement element is less impact on the change of the output torque T _oUT, rather preferred in order to shorten the shift time.

In FIG. 17, during the shift transition period, the period until the disengagement side frictional engagement element is released and has no torque capacity, and the engagement side frictional engagement element is engaged and begins to have torque capacity, for example, t. ₂ point to t ₃ time or t ₅ time to t ₆ time, since the automatic transmission is a power transmission interrupted state, the output torque is a 0N · m.

JP-A-6-331010

However, when the power source is output torque T _OUT as shown in t ₃ after the point of FIG. 17 is a negative value is in the driven state, the second shift output at t ₄ time as described above Accordingly, when the disengagement side frictional engagement element is quickly released and the power transmission is cut off, the output torque T _OUT is changed from a negative value to 0 N ··· as shown at the time t _{4 to the} time t _5. Because of the rapid change toward m, drivability may be deteriorated.

  The present invention has been made against the background of the above circumstances, and its object is to release the first frictional engagement element and engage the second frictional engagement element during inertial running of the vehicle. In the vehicular automatic transmission in which the power off upshift is performed by the power offup shift, the output of the vehicular automatic transmission accompanying the release of the first friction engagement element when the power source is in the driven state is performed during the power off upshift. An object of the present invention is to provide a hydraulic control device for an automatic transmission for a vehicle in which a change in torque is suppressed and drivability is improved.

The gist of the invention according to claim 1 for achieving such an object is as follows: (a) During the inertia running of the vehicle, the operating oil pressure of the first friction engagement element is reduced to reduce the first friction engagement element. And a hydraulic control device for an automatic transmission for a vehicle that performs a power-off upshift by increasing the operating hydraulic pressure of the second friction engagement element and engaging the second friction engagement element. (b) power source state determining means for determining whether the power source at the start of shifting of the power off upshift is in a driving state or a driven state; and (c) when it is determined that the power source is in a driving state. The hydraulic pressure of the first friction engagement element is decreased relatively quickly, while when the power source is determined to be in a driven state, compared to when the power source is determined to be in a driven state. Hydraulic oil for the first friction engagement element Relatively gentle manner reduces, the first frictional engagement element during the power-off upshift based on the determination result by the power source state determining means to its first frictional engagement element is released And a hydraulic pressure lowering control means for changing the mode of lowering the operating hydraulic pressure.

In this way, when it is determined that the power source is in the driving state, the hydraulic pressure of the first friction engagement element is relatively quickly reduced, while the power source is determined to be in the driven state. The operating oil pressure of the first friction engagement element is relatively lowered until the first friction engagement element is released compared to when the power source is determined to be in the drive state. The hydraulic pressure of the first friction engagement element at the time of the power-off upshift based on the determination result by the power source state determination means for determining whether the power source is in the driven state or the driven state at the start of shifting of the power-off upshift. Since the mode for reducing the hydraulic pressure is changed by the hydraulic pressure reduction control means, at the time of the power-off upshift, the shift time when the power source is in the drive state is suppressed and the power source is covered. The change in the output torque of the vehicle automatic transmission from the negative value to 0 N · m associated with the release of the first friction engagement element when in the moving state causes the operating oil pressure of the first friction engagement element to be a power source. Since drivability is suppressed as compared with the case where it is rapidly reduced as in the driving state, drivability is improved.

  Here, the invention according to claim 2 is the hydraulic control device for the automatic transmission for vehicle according to claim 1, wherein the automatic transmission for vehicle receives the output of the power source input via the fluid transmission device. The power source state determining means transmits the power to the drive wheel, and the power source state determining means determines whether the power source is in a driven state based on a rotational speed difference between the output shaft rotational speed of the power source and the input shaft rotational speed of the vehicle automatic transmission. It is to determine whether the driving state. In this way, it is appropriately determined whether the power source is in a driven state or a driven state. For example, if the rotational speed difference between the output shaft rotational speed of the power source and the input shaft rotational speed of the vehicle automatic transmission is equal to or greater than a predetermined rotational speed, the power source is determined to be in the driving state, while the rotational speed difference Is less than a predetermined rotational speed, it is determined that the power source is in a driven state.

  According to a third aspect of the present invention, in the hydraulic control device for an automatic transmission for a vehicle according to the first aspect, the power source state determination means is configured to determine the power based on an elapsed time from the start of inertial traveling of the vehicle. Whether the source is in a driven state or a driven state is determined. In this way, it is appropriately determined whether the power source is in a driven state or a driven state. For example, if the elapsed time from the start of coasting of the vehicle is less than a predetermined time, it is determined that the power source is in a driving state, while if the elapsed time is equal to or longer than the predetermined time, the power source is in a driven state. It is judged.

  According to a fourth aspect of the present invention, in the hydraulic control device for an automatic transmission for a vehicle according to the first aspect, the automatic transmission for the vehicle is input with the power source input via a fluid transmission with a lock-up clutch. The power source state determination means rotates between the output shaft rotational speed of the power source and the input shaft rotational speed of the vehicle automatic transmission when the lockup clutch is released. While determining whether the power source is driven or driven based on the speed difference, when the lockup clutch is engaged, whether the power source is driven or not based on the elapsed time from the start of coasting of the vehicle. It is to determine whether the driving state. In this way, it is appropriately determined whether the power source is in the driven state or the driven state regardless of whether or not the lockup clutch is engaged. For example, when the lockup clutch is released, the power source is in a driving state if the difference in rotational speed between the output shaft rotational speed of the power source and the input shaft rotational speed of the vehicle automatic transmission is equal to or greater than a predetermined rotational speed. On the other hand, if the rotational speed difference is less than the predetermined rotational speed, it is determined that the power source is in a driven state. Also, when the lockup clutch is engaged and the rotational speed difference between the output shaft rotational speed of the power source and the input shaft rotational speed of the vehicle automatic transmission is not very small, If the elapsed time is less than the predetermined time, it is determined that the power source is in a driving state, while if the elapsed time is longer than the predetermined time, it is determined that the power source is in a driven state.

  Preferably, the vehicular automatic transmission includes a planetary gear type multi-stage transmission in which gear stages are switched by selectively connecting rotating elements of a plurality of sets of planetary gear devices by friction engagement elements, and the like. It is constituted by various types of automatic transmissions that perform gear shifting by selectively engaging and releasing a plurality of friction engagement elements.

  Further, the mounting posture of the above-described vehicle automatic transmission with respect to the vehicle may be a horizontal installation type such as an FF (front engine / front drive) vehicle in which the transmission axis is in the width direction of the vehicle. A vertical installation type such as an FR (front engine / rear drive) vehicle may be used.

  Further, the planetary gear type multi-stage transmission may be any one that can achieve a plurality of gear stages alternatively. For example, the planetary gear type multi-stage transmission includes various forward speeds such as 5 forward speeds, 6 forward speeds, 7 forward speeds, and 8 forward speeds. A multi-stage automatic transmission can be used.

  Preferably, as the friction engagement element, a multi-plate type, single plate type clutch or brake engaged by a hydraulic actuator, or a belt type brake is widely used. The oil pump that supplies the hydraulic pressure for engaging the friction engagement element may be driven by a driving power source such as an engine or an electric motor to discharge the hydraulic oil. Alternatively, it may be driven by a dedicated electric motor arranged separately.

  Preferably, the hydraulic control circuit including the friction engagement element preferably supplies, for example, the output hydraulic pressure of the linear solenoid valve directly to the hydraulic actuator (hydraulic cylinder) of the friction engagement element. However, it is also possible to control the shift control valve by using the output hydraulic pressure of the linear solenoid valve as the pilot hydraulic pressure, and to supply the hydraulic oil from the control valve to the hydraulic actuator.

  Preferably, the plurality of linear solenoid valves are provided one by one corresponding to each of the plurality of friction engagement elements, for example, but are not simultaneously engaged or controlled to be engaged or released. When there are a plurality of friction engagement elements, various modes are possible, such as providing a common linear solenoid valve for them. In addition, it is not always necessary to perform hydraulic control of all the friction engagement elements with the linear solenoid valve, and part or all of the hydraulic control is performed with pressure regulating means other than the linear solenoid valve, such as duty control of the ON-OFF solenoid valve. May be.

  Preferably, an internal combustion engine such as a gasoline engine or a diesel engine is used as the engine.

  Preferably, a torque converter, a fluid coupling, or the like is used as the fluid transmission device.

  In this specification, “supplying hydraulic pressure” means “applying hydraulic pressure” or “supplying hydraulic oil controlled to the hydraulic pressure”.

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

  FIG. 1 is a skeleton diagram of a vehicular automatic transmission (hereinafter referred to as an automatic transmission) 10. FIG. 2 is an operation table for explaining an operation state of the friction engagement element, that is, the friction engagement device when a plurality of shift speeds are established. The automatic transmission 10 is preferably used for an FF vehicle mounted in the left-right direction (horizontal) of the vehicle, and is a single pinion type first in a transmission case 26 as a non-rotating member attached to the vehicle body. A first transmission unit 14 mainly composed of one planetary gear unit 12, a double pinion type second planetary gear unit 16 and a single pinion type third planetary gear unit 18 are mainly composed of a Ravigneaux type. The second transmission unit 20 is provided on a common axis C, and the rotation of the input shaft 22 is shifted and output from the output rotation member 24. The input shaft 22 corresponds to an input member. In this embodiment, the input shaft 22 is a turbine shaft of a torque converter 32 as a fluid transmission device that is rotationally driven by an engine 30 that is a power source for traveling. The output rotating member 24 corresponds to the output member of the automatic transmission 10, and an output gear that meshes with the differential driven gear (large-diameter gear) 42 to transmit power to the differential gear device 40 shown in FIG. That is, it functions as a differential drive gear. The output of the engine 30 is transmitted to the pair of drive wheels 46 via the torque converter 32, the automatic transmission 10, the differential gear device 40, and the pair of axles 44. The automatic transmission 10 and the torque converter 32 are substantially symmetrical with respect to the center line (axial center) C, and the lower half of the center line C is omitted in the skeleton diagram of FIG. .

  The torque converter 32 includes a lockup clutch 34 as a lockup mechanism that directly transmits the power of the engine 30 to the input shaft 22 without passing through fluid. The lock-up clutch 34 is a hydraulic friction clutch that is frictionally engaged by a differential pressure ΔP between the hydraulic pressure in the engagement-side oil chamber 36 and the hydraulic pressure in the release-side oil chamber 38, and is completely engaged (locked). The power of the engine 30 is directly transmitted to the input shaft 22 by being turned on. Further, the differential pressure ΔP, that is, the torque capacity is feedback-controlled so as to be engaged in a predetermined slip state, so that the turbine shaft (input shaft 22) has a predetermined slip amount of, for example, about 50 rpm when the vehicle is driven (power-on). Is rotated following the output shaft of the engine 30, while the output shaft of the engine 30 is rotated following the turbine shaft with a predetermined slip amount of, for example, about -50 rpm when the vehicle is not driven (power off).

  The automatic transmission 10 corresponds to a combination of any one of the rotational states (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) of the first transmission unit 14 and the second transmission unit 20 according to the combination. Six forward shift stages (forward gear stages) from the first shift stage “1st” to the sixth shift stage “6th” are established, and the reverse shift stage (reverse gear stage) of the reverse shift stage “R” is established. It is done. As shown in FIG. 2, for example, in the forward gear stage, the first speed gear stage is engaged by the engagement of the clutch C1 and the brake B2, and the second speed gear stage is engaged by the engagement of the clutch C1 and the brake B1, and the clutch C1 is engaged. The third gear is set by engagement with the brake B3, the fourth gear is set by engagement of the clutch C1 and the clutch C2, and the fifth gear is set by engagement of the clutch C2 and the brake B3. The sixth gear is established by engaging the brake B1. Further, the reverse gear stage is established by the engagement of the brake B2 and the brake B3, and the neutral state is established by releasing any of the clutches C1, C2 and the brakes B1 to B3.

  The operation table of FIG. 2 summarizes the relationship between the above-mentioned shift speeds and the operation states of the clutches C1, C2 and the brakes B1 to B3, where “◯” indicates engagement and “◎” indicates only during engine braking. Represents the event. Since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first shift stage “1st”, it is not always necessary to engage the brake B2 at the time of start (acceleration). Further, the gear ratios of the respective gear stages are the gear ratios of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18 (= number of teeth of the sun gear / number of teeth of the ring gear) ρ1, ρ2. , Ρ3 as appropriate.

  The clutches C1 and C2 and the brakes B1 to B3 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are hydraulic friction engagement elements that are controlled by a hydraulic actuator such as a multi-plate clutch or a brake. (Hydraulic friction engagement device), the engagement and release states are switched by the excitation, de-excitation and current control of the linear solenoid valves SL1 to SL5 of the hydraulic control circuit 50 (see FIG. 3) and the engagement and release The transient oil pressure at the time is controlled.

  FIG. 3 is a block diagram illustrating a main part of an electrical control system provided in the vehicle for controlling the automatic transmission 10 of FIG. The electronic control device 100 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, and the CPU uses a temporary storage function of the RAM according to a program stored in the ROM in advance. By performing signal processing, output control of the engine 30, shift control of the automatic transmission 10, on / off control of the lockup clutch 34, and the like are executed, and for engine control and linear solenoid valve SL 1 as necessary. Are configured separately for shift control for controlling SL5, lock-up clutch control for controlling the linear solenoid valve SLU and the solenoid valve SL of the hydraulic control circuit 50, and the like.

In Figure 3, the accelerator pedal 52, known as a so-called accelerator opening operating amount Acc of the accelerator operation amount sensor 54 for detecting, of the engine 30 as an output shaft rotation speed of the power source rotation speed N _E for detecting engine rotational speed sensor 56, coolant temperature sensor 58 for detecting the cooling water temperature T _W of the engine 30, the intake air quantity sensor 60 for detecting an intake air quantity Q of the engine 30, detects the temperature T _a of intake air An intake air temperature sensor 62 for detecting the opening degree θ _TH of the electronic throttle valve, a vehicle speed sensor for detecting the vehicle speed V (corresponding to the rotational speed N _OUT of the output rotating member 24). 66, brake switch 70 for detecting the presence or absence of operation of foot brake pedal 68, which is a service brake, and shift lever 72 Bar position (operating position) P lever position sensor 74 _{for SH} detecting a turbine rotational speed N _T or input shaft 22 of the rotational speed N _IN turbine speed sensor 76 for detecting the actuation of the hydraulic control circuit 50 An AT oil temperature sensor 78 for detecting an AT oil temperature T _OIL that is the temperature of the oil is provided, and the engine rotation speed N _E , the engine cooling water temperature T _W , the intake air amount are detected from these sensors and switches. Q, intake air temperature T _A , throttle valve opening θ _TH , vehicle speed V, output shaft rotation speed N _OUT , presence or absence of brake operation, lever position P _SH of shift lever 72, turbine rotation speed N _T (= input shaft rotation speed) N _IN ), AT oil temperature T _{OIL and the} like are supplied to the electronic control unit 100.

4 is a linear solenoid valve that controls the operation of the hydraulic actuators (hydraulic cylinders) A _C1 , A _C2 , A _B1 , A _B2 , A _B3 of the clutches C1, C2 and the brakes B1 to B3 in the hydraulic control circuit 50. It is a circuit diagram regarding SL1 to SL5.

In FIG. 4, the hydraulic pressures A _C1 , A _C2 , A _B1 , A _B2 , A _B3 are applied to the line hydraulic pressure PL by linear solenoid valves SL1 to SL5, respectively, according to command signals from the electronic control unit 100. The pressure is adjusted to P _C1 , P _C2 , P _B1 , P _B2 , and P _B3 and supplied directly. This line oil pressure PL is obtained by using, for example, a relief type pressure regulating valve (regulator valve) (not shown) with the hydraulic pressure generated from a mechanical oil pump 28 (see FIG. 1) rotated and driven by the engine 30 as a source pressure. The pressure is adjusted to a value corresponding to the engine load or the like represented by the opening.

The linear solenoid valves SL1 to SL5 have basically the same configuration, and are excited and de-energized independently by the electronic control unit 100, and the hydraulic pressure of each hydraulic actuator A _C1 , A _C2 , A _B1 , A _B2 , A _B3 . Are independently regulated to control the engagement pressures P _C1 , P _C2 , P _B1 , P _B2 , and P _{B3 of} the clutches C1 to C4 and the brakes B1 and B2. In the automatic transmission 10, for example, as shown in the engagement operation table of FIG. 2, each gear stage is established by engaging a predetermined engagement device. In the shift control of the automatic transmission 10, for example, a so-called clutch-to-clutch shift is performed in which release and engagement of the clutch C and the brake B involved in the shift are controlled simultaneously. For example, as shown in the engagement operation table of FIG. 2, in the upshift from the third speed to the fourth speed, the brake B3 is released and the clutch C2 is engaged, and the release transient hydraulic pressure of the clutch C2 is suppressed so as to suppress the shift shock. And the engagement transient hydraulic pressure of the clutch C4 are appropriately controlled.

  Returning to FIG. 3, the solenoid valve SL and the linear solenoid valve SLU provided in the hydraulic control circuit 50 are excited and de-energized by the electronic control unit 100, and the lockup clutch 34 is turned on (engaged) and turned off by the solenoid valve SL. (Release) is switched to the ON side, and the torque capacity of the lockup clutch 34, that is, the differential pressure ΔP, is regulated by the linear solenoid valve SLU, so that the torque converter 32 is slipped or locked up. (Complete engagement) is controlled.

FIG. 5 is a functional block diagram illustrating the main part of the control function of the electronic control device 100. In FIG. 5, the lock-up clutch control means 102 has a release (lock-up off) region, a slip control region, an engagement in a two-dimensional coordinate having the throttle valve opening θ _TH and the vehicle speed V as parameters as shown in FIG. Based on the actual vehicle running state, for example, the throttle valve opening degree θ _TH and the vehicle speed V, from the previously stored relationship (map, lockup region diagram) having the (lockup on) region, the operating state of the lockup clutch 34 is determined. Control switching.

  For example, the lock-up clutch control means 102 outputs a control command for the solenoid valve SL to the hydraulic control circuit 50 to switch the lock-up clutch 34 to the lock-up off or to switch to the slip or lock-up on. A control command for the linear solenoid valve SLU is output to the hydraulic control circuit 50 for controlling the pressure ΔP.

  The shift control means 104 determines shift based on the actual vehicle speed V and the accelerator operation amount Acc from the relationship (map, shift diagram) stored in advance with the vehicle speed V and the accelerator operation amount Acc as parameters as shown in FIG. 7, for example. To determine whether or not the automatic transmission 10 should be shifted. For example, the automatic transmission 10 is automatically determined so as to obtain the determined shift speed. Shift control is executed. At this time, the shift control means 104 engages and / or releases the hydraulic friction engagement device involved in the shift of the automatic transmission 10 so that the shift stage is achieved according to, for example, the engagement table shown in FIG. A command (shift output, hydraulic command) is output to the hydraulic control circuit 50.

The hydraulic control circuit 50 operates the linear solenoid valves SL1 to SL5 in the hydraulic control circuit 50 so that the shift of the automatic transmission 10 is executed according to the command, and the hydraulic friction engagement device involved in the shift Hydraulic actuators A _C1 , A _C2 , A _B1 , A _B2 , A _B3 are operated.

In the shift diagram of FIG. 7, a solid line is a shift line (upshift line) for determining an upshift, and a broken line is a shift line (downshift line) for determining a downshift. Further, the shift line in the shift diagram of FIG. 7 indicates whether or not the actual vehicle speed V crosses the line on the horizontal line indicating the actual accelerator operation amount Acc (%), that is, the value on which the shift on the shift line is to be executed ( It is for determining whether exceeds the shift point vehicle speed) V _S, also will have been previously stored as a series of the values V _S that shift point vehicle speed.

  For example, when the vehicle is traveling in the third speed gear stage, the shift control means 104 sets a third speed → fourth speed upshift line in which the actual accelerator operation amount Acc is to execute the third speed → fourth speed upshift by turning off the accelerator. If it is determined that the vehicle has crossed the 4th gear → 5th gear upshift line where the 4th gear → 5th gear upshift should be performed, the first friction engagement element, that is, the disengagement side engagement device (the disengagement side engagement device) The operating hydraulic pressure of the brake B3 as the combination element) is decreased to release the brake B3, and the operating hydraulic pressure of the clutch C2 as the second friction engagement element, that is, the engagement side engagement device (engagement side engagement element) is increased. The first shift output (3 → 4 power-off upshift) for engaging the clutch C2 is output to the hydraulic control circuit 50, and after the fourth gear stage is established, the clutch C1 as the first friction engagement element is continuously applied. Product Hydraulic control of the second shift output (4 → 5 power off upshift) that lowers the hydraulic pressure to release the clutch C1 and increases the hydraulic pressure of the brake B3 as the second friction engagement element to engage the brake B3 Output to the circuit 50.

Specific examples thereof in the first shift output (or the second shift output), the working oil pressure of the brake B3 (or clutch C1) is rapidly reduced thereby as shown in time point t ₁ in FIG. 17 (or t ₄ time) In this way, a hydraulic pressure command for making the minimum value MIN from the maximum value MAX at a stroke is output to the linear solenoid valve SL5 (or linear solenoid valve SL1), and the brake B3 (or clutch C1) as the disengagement side frictional engagement device is promptly The drain hydraulic pressure control to be released is executed.

Moreover, the working oil pressure supply of the first shift output as shown in time point _{t 1} to _{t 4} time of FIG. 17 (or _{t 4} time to _{t 7} time) (or the second shift output), the clutch C2 (or the brake B3) At the start, a high hydraulic pressure command is output so that the hydraulic fluid is quickly filled in order to quickly pack the pack clearance of the clutch C2 (or brake B3). Therefore, a low hydraulic pressure command is output once at the start of engagement, and then the hydraulic pressure command is output to the linear solenoid valve SL2 (or linear solenoid valve SL5) so as to gradually increase toward the hydraulic pressure value at the completion of engagement. Thus, the apply hydraulic pressure control is performed in which the clutch C2 (or the brake B3) that is the engagement side frictional engagement device is engaged.

The drain hydraulic pressure control in which the aforementioned release side frictional engagement device is quickly released is executed when the output torque (output torque) T _{OUT of the} automatic transmission 10 is a positive value and the power source is in the driving state. that when, since the output torque T _oUT as shown in time point t ₁ to t ₂ time is lowered toward the positive value to a negative value, originally the output torque T _oUT with the accelerator off positive sometimes changes from a value to a negative value, reducing the drain oil pressure control impact on change in the output torque T _OUT of the release side frictional engagement device is released quickly, rather, in order to shorten the shift time preferable.

However, when the output torque T _OUT is the power source to a negative value of the release-side friction engagement drain hydraulic control the automatic transmission 10 coupling device is released rapidly to run when a driven state, t output torque T _OUT as shown in ₄ time to t ₅ when the order changes rapidly towards 0N · m from a negative value, there is a possibility that drivability is deteriorated.

  Therefore, in order to improve the drivability during the power-off upshift, a mode in which the hydraulic pressure of the first friction engagement element during the power-off upshift is reduced based on whether the power source is in the driven state or the driven state. change. Hereinafter, the control operation will be described.

  Returning to FIG. 5, the inertia traveling determination means 106 determines whether or not the vehicle is decelerating with the accelerator off, that is, coasting (coast traveling), based on the accelerator operation amount Acc.

  The power source state determination means 108 determines, for example, that the vehicle is in inertia traveling at the start of shifting of the power-off upshift, and the shift control means 104 as shown in FIG. It is determined from the shift diagram whether the engine 30 is in a driven state or a driven state when it is determined that an upshift of the automatic transmission 10 should be executed based on the actual vehicle speed V and the accelerator operation amount Acc.

For example, the power source state determination means 108 drives the engine 30 based on the rotational speed difference ΔN (= N _E −N _T ) between the engine rotational speed _NE and the turbine rotational speed _NT (input shaft rotational speed N _IN ). It is determined whether it is in a state or a driven state. That is, it is determined whether the engine 30 is in a driven state or a driven state using a difference in rotational speed between the input side of the torque converter, that is, the engine 30 side, and the output side, that is, the driving wheel 46 side.

Specifically, the power source state determination unit 108 includes a rotation speed difference determination unit 110 that determines whether or not the rotation speed difference ΔN is greater than or equal to a predetermined rotation speed ΔN ^* , and is rotated by the rotation speed difference determination unit 110. If it is determined that the speed difference ΔN is greater than or equal to the predetermined rotational speed ΔN ^*, it is determined that the engine 30 is in a driving state, while the rotational speed difference determination means 110 determines that the rotational speed difference ΔN is less than the predetermined rotational speed ΔN ^* . If it is determined that there is, it is determined that the engine 30 is in a driven state.

The predetermined rotational speed .DELTA.N ^*, when it is determined that the engine 30 with the engine rotational speed N _E is higher rotational speed than the turbine speed N _T is in the driving state is a zero rotational speed, the negative It can be applied even if the rotational speed is included and the rotational speed is other than the zero rotational speed. For example, the predetermined rotation speed ΔN ^* is determined by changing the operating pressure of the first friction engagement element so that the drivability at the time of power-off upshifting is improved. It is also possible to use a determination rotational speed determined experimentally in advance for determining whether or not.

  The hydraulic pressure reduction control unit 112 determines that the engine 30 is in the driven state while the hydraulic pressure of the first friction engagement element is relatively quickly reduced when the engine 30 is determined to be in the driven state. Sometimes, the hydraulic pressure of the first friction engagement element during the power-off upshift is based on the determination result by the power source state determination means 108 so that the hydraulic pressure of the first friction engagement element is relatively gradually decreased. Change the mode of lowering.

  For example, when the power source state determination unit 108 determines that the engine 30 is in the driving state, the hydraulic pressure reduction control unit 112 is configured so that the operating hydraulic pressure of the first friction engagement element is quickly decreased during the upshift. The shift control means 104 is caused to output a hydraulic pressure command that makes the minimum value MIN from the maximum value MAX at a stretch, and the immediate drain hydraulic pressure control in which the first friction engagement element is quickly released is executed. Thereby, at the time of a power-off upshift, an increase in the shift time when the engine 30 is in a driving state is suppressed.

When the power source state determination unit 108 determines that the engine 30 is in the driven state, the hydraulic pressure reduction control unit 112 determines that the operating hydraulic pressure of the first friction engagement element is in the driving state during the upshift. The hydraulic pressure command is output to the shift control means 104 so as to gradually decrease from the maximum value MAX at a predetermined rate to the minimum value MIN so that the speed can be decreased relatively slowly as compared with the case where the speed is quickly decreased. Thus, the sweep drain hydraulic pressure control is performed in which the first friction engagement element is gently released. Thus, during the power-off upshift, the change in the output torque T _OUT from the negative value to 0 N · m with the release of the first friction engagement element when the engine 30 is in the driven state is caused by the first friction. The operating hydraulic pressure of the engaging element is suppressed as compared with rapidly decreasing as in the case where the engine 30 is in a driving state.

  FIG. 8 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device 100, that is, a mode of reducing the hydraulic pressure of the first friction engagement element at the time of power-off upshift, for example, several msec. It is repeatedly executed with an extremely short cycle time of about several tens of milliseconds. FIG. 9 is a time chart for explaining the control operation shown in the flowchart of FIG.

  First, in step (hereinafter, step is omitted) SA1 corresponding to the inertia traveling determination unit 106 and the shift control unit 104, whether or not the vehicle is in inertial traveling with the accelerator off based on the accelerator operation amount Acc is determined. At the same time, a determination is made as to whether or not a shift of the automatic transmission 10 should be executed based on the actual vehicle speed V and the accelerator operation amount Acc, for example, from the shift diagram as shown in FIG. It is determined whether or not it is time to start shifting. SA1 indicates a case where it is already determined that the power-off upshift is started. If it is determined that it is not at the time of starting the power-off upshift, this routine is terminated.

T ₀ point of Figure 9 shows that the coasting of the accelerator-off is determined. Further, t ₁ point is determined 3 speed during coasting → 4 gear upshift (first gear), t ₄ when fourth speed → 5-speed up-shift during coasting (second shift) is determined It is shown that.

Next, in SA2 corresponding to the power source state determination means 108 (rotational speed difference determination means 110), it is determined whether the engine 30 is in a driven state or a driven state. Therefore, the rotational speed difference ΔN is determined to be a predetermined rotational speed ΔN ^*. It is determined whether or not this is the case.

Time point t ₁ in FIG. 9 is determined to the rotational speed difference .DELTA.N is the predetermined rotational speed .DELTA.N ^* or engine 30 is determined to be in the driving state, t ₄ when the rotational speed difference .DELTA.N is less than the predetermined rotational speed .DELTA.N ^* It is determined that the engine 30 is determined to be in a driven state.

  If the determination at SA2 is affirmative, the engine 30 is in a driving state, so that at SA3 corresponding to the hydraulic pressure decrease control means 112, the speed change is performed so that the operating hydraulic pressure of the first friction engagement element is quickly decreased. The control means 104 is caused to output a hydraulic pressure command from the maximum value MAX to the minimum value MIN at once, and the immediate drain hydraulic pressure control in which the first friction engagement element is quickly released is executed.

Time point t ₁ in FIG. 9, as the working oil pressure of the brake B3 are rapidly lowered, the hydraulic pressure value command is a linear solenoid to stretch minimum value MIN from the maximum value MAX as the first shift drain the hydraulic control of the first shift output It shows that the immediate drain hydraulic pressure control output to the valve SL5 is executed.

  When the determination in SA2 is negative, the engine 30 is in a driven state, and therefore in SA4 corresponding to the hydraulic pressure reduction control means 112, when the operating hydraulic pressure of the first friction engagement element is in the driving state. Thus, the shift control means 104 is made to output a hydraulic pressure command for making the minimum value MIN gradually decreasing at a predetermined rate from the maximum value MAX so that it can be decreased relatively slowly as compared with the case where it is quickly decreased. Thus, sweep drain hydraulic pressure control is performed in which the first friction engagement element is gently released.

T ₄ time in FIG. 9, so that the working oil pressure of the clutch C1 is lowered relatively slowly, the minimum value while gradually decreasing from a maximum value MAX at a predetermined rate as the second shift drain oil pressure control of the second shift output MIN The sweep drain hydraulic pressure control in which the hydraulic pressure command is output to the linear solenoid valve SL1 is executed. Thus, rapidly changing toward the immediate drain control is executed by t ₄ time to output torque T _OUT at t ₅ when a negative value at t ₄ time as in the conventional example shown by the broken line in 0N · m In comparison with this, the output torque T _OUT changes gradually from a negative value toward 0 N · m as shown from the time t _{4 to the} time t ₅ ′.

As described above, according to the present embodiment, when it is determined that the engine 30 is in the driving state, the operating hydraulic pressure of the first friction engagement element is relatively quickly reduced, while the engine 30 is in the driven state. A power source for determining whether the engine 30 is in a driven state or a driven state at the start of shifting of the power-off upshift so that the operating hydraulic pressure of the first friction engagement element is relatively gradually decreased when it is determined Since the hydraulic pressure reduction control unit 112 changes the mode of reducing the operating hydraulic pressure of the first friction engagement element based on the determination result by the state determination unit 108, the engine 30 is changed during the power off upshift. When the engine 30 is in the driving state, the shifting time is prevented from being prolonged, and the first friction engagement element is released when the engine 30 is in the driven state. Change the output torque T _OUT of the Hare automatic transmission 10 is directed from a negative value to 0N · m is compared working oil pressure of the first frictional engagement element to quickly reduce as when the engine 30 is driven state Therefore, drivability is improved because it is suppressed.

Further, according to this embodiment, the power source state determination means 108 drives the engine 30 based on the rotational speed difference ΔN (= N _E −N _T ) between the engine rotational speed _NE and the input shaft rotational speed N _IN. Or the driven state is appropriately determined.

  Next, another embodiment of the present invention will be described. In the following description, parts common to the embodiments are denoted by the same reference numerals and description thereof is omitted.

In such an embodiment, the power source state determining means 108, whether the engine 30 is driven state based on the rotation speed difference ΔN between the engine speed N _E and the turbine rotational speed N _{T (input} shaft rotational speed N _IN) to be Although it is determined whether the driving state, instead it engine 30 or the driven state or driving state based on the elapsed time t _oFF from the elapsed time t _oFF i.e. accelerator pedal from coasting start of the vehicle in this embodiment Judging. That is, the engine 30 in consideration of the response delay of the output torque T _OUT changes other words response delay of the output torque T _E changes in the engine 30 to the operation of the accelerator pedal 52 to determine whether the driven state or a driving state.

Specifically, FIG. 10 is a functional block diagram illustrating the main part of the control function of the electronic control device 100, and corresponds to FIG. In FIG. 10, the power source state determination means 108 determines that the vehicle is coasting by the elapsed time t _OFF from the accelerator-off state, for example, the coasting determination means 106 instead of the rotational speed difference determination means 110. Elapsed time t _OFF since the elapsed time t _OFF is less than the predetermined time t _OFF ^{*. The} elapsed time determination unit 114 determines whether the elapsed time t _OFF is less than the predetermined time t _OFF ^* . If it is determined that the engine 30 is in a driving state, the elapsed time determination unit 114 determines that the elapsed time t _OFF is equal to or greater than the predetermined time t _OFF ^*. Judged to be in a driving state.

The predetermined time t _OFF ^* is the output torque T of the engine 30 that accompanies the accelerator off because the manner in which the operating oil pressure of the first friction engagement element is lowered is changed so that the drivability during the power-off upshift is improved. _E is a determination time that is determined experimentally and determined in advance for determining whether the engine 30 is in a driven state or a driven state in consideration of response delay of change.

  FIG. 11 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device 100, that is, a mode of reducing the operating hydraulic pressure of the first friction engagement element at the time of power-off upshift, for example, several msec. It is repeatedly executed with an extremely short cycle time of about several tens of milliseconds. FIG. 11 shows another embodiment corresponding to FIG. 8, and the determination method for determining whether the engine 30 executed in SB2 is in a driven state or a driven state is particularly different from SA2 in FIG. This difference is mainly described in the flowchart of FIG. FIG. 12 is a time chart for explaining the control operation shown in the flowchart of FIG. 11, and corresponds to FIG.

  First, in SB1 corresponding to the inertia running determination means 106 and the shift control means 104, it is determined whether or not it is time to start shifting of the power-off upshift. This SB1 shows a case where it is already determined that the power-off upshift is started. If it is determined that it is not at the time of starting the power-off upshift, this routine is terminated.

T ₀ point of Figure 12 shows that the coasting of the accelerator-off is determined. Further, t ₁ point is determined 3 speed during coasting → 4 gear upshift (first gear), t ₄ when fourth speed → 5-speed up-shift during coasting (second shift) is determined It is shown that.

Next, in SB2 corresponding to the power source state determination means 108 (elapsed time determination means 114), since it is determined whether the engine 30 is in a driving state or a driven state, the elapsed time t _OFF since the accelerator is off is a predetermined time. It is determined whether or not it is less than t _OFF ^* .

At time t _{1 in} FIG. 12, it is determined that the elapsed time t _OFF from the accelerator off is less than the predetermined time t _OFF ^{* and} it is determined that the engine 30 is in the driving state, and at time t ₄ , the elapsed time t from the accelerator off. _This indicates that it is determined that _OFF is equal to or longer than the predetermined time t _OFF ^* and the engine 30 is determined to be in a driven state.

  If the determination of SB2 is affirmative, the engine 30 is in a driving state, and therefore in SB3 corresponding to the hydraulic pressure decrease control means 112, the immediate drain hydraulic control in which the first friction engagement element is quickly released is executed. It is done.

Time point t ₁ in FIG. 12, as the working oil pressure of the brake B3 it is quickly reduced, indicating that the immediately drain the hydraulic control is allowed to execute.

  If the determination in SB2 is negative, the engine 30 is in a driven state, and therefore, in SB4 corresponding to the hydraulic pressure lowering control unit 112, the sweep drain hydraulic pressure control in which the first friction engagement element is gradually released is executed. Be made.

T ₄ time of FIG. 12 shows that the hydraulic pressure of the clutch C1 is relatively gently to be reduced, the sweep drain hydraulic control is allowed to execute. Thus, rapidly changing toward the immediate drain control is executed by t ₄ time to output torque T _OUT at t ₅ when a negative value at t ₄ time as in the conventional example shown by the broken line in 0N · m In comparison with this, the output torque T _OUT changes gradually from a negative value toward 0 N · m as shown from the time t _{4 to the} time t ₅ ′.

As described above, according to the present embodiment, the hydraulic pressure reduction control unit 112 is configured to reduce the operating hydraulic pressure of the first friction engagement element during the power-off upshift based on the determination result by the power source state determination unit 108. Therefore, at the time of power-off upshifting, the lengthening of the shift time when the engine 30 is in the driving state is suppressed, and the first friction engagement element is released when the engine 30 is in the driven state. The change in the output torque T _OUT of the automatic transmission 10 from the negative value to 0 N · m due to the rapid decrease in the hydraulic pressure of the first friction engagement element as in the engine 30 drive state. In comparison, drivability is improved because it is suppressed.

Further, according to the present embodiment, whether the engine 30 is in the driven state or the driven state based on the elapsed time t _OFF from the starting point of inertial driving of the vehicle, that is, the elapsed time t _OFF from the accelerator off, is determined by the power source state determining means 108. Is appropriately determined.

In such an embodiment, the power source state determining means 108, whether the engine 30 is driven state based on the rotation speed difference ΔN between the engine speed N _E and the turbine rotational speed N _{T (input} shaft rotational speed N _IN) to be It is determined whether the engine 30 is in a driving state or whether the engine 30 is in a driving state or a driven state based on an elapsed time t _OFF from the start of inertial traveling of the vehicle.

Here, in the determination of whether the engine 30 is in the driven state or the driven state by the power source state determining means 108, the determination method based on the rotational speed difference ΔN is compared with the determination method based on the elapsed time t _OFF from the accelerator off. The accuracy is considered high. On the other hand, when the lockup clutch 34 is engaged, the determination based on the rotational speed difference ΔN becomes difficult. Therefore, when the lockup clutch 34 is engaged, the determination method based on the elapsed time t _OFF from the accelerator off is an effective determination. It is considered a method.

Therefore, in this embodiment, the power source state determination means 108 determines whether the engine 30 is in the driving state based on the rotational speed difference ΔN when the lock-up clutch 34 is released at the start of the power-off upshift. While determining whether the engine 30 is in a driving state, when the lockup clutch 34 is engaged including a slip state, it is determined whether the engine 30 is in a driving state or a driven state based on an elapsed time t _OFF from the start of inertial running of the vehicle. To do.

  Specifically, FIG. 13 is a functional block diagram for explaining a main part of the control function by the electronic control device 100, and corresponds to FIG. In FIG. 13, the lock-up determining means 116 is based on a control command for the solenoid valve SL output to the hydraulic control circuit 50 for switching the lock-up clutch 34 from the lock-up clutch control means 102 to slip or lock-up on. Thus, it is determined whether or not the lockup clutch 34 is slipping or lockup on, that is, lockup control is being executed.

The power source state determination means 108 is provided with the rotational speed difference determination means 110 and the elapsed time determination means 114 in place of the above-described embodiment, so that the lockup clutch control means 102 switches to slip or lockup on. When the control command to the solenoid valve SL is not output and the lockup determination unit 116 determines that the lockup clutch 34 is being released, the rotation speed difference determination unit 110 sets the rotation speed difference ΔN to a predetermined value. When it is determined that the rotational speed ΔN ^{* is} greater than or equal to the rotational speed ΔN ^*, it is determined that the engine 30 is in a driving state, while the rotational speed difference determination unit 110 determines that the rotational speed difference ΔN is less than the predetermined rotational speed ΔN ^*. It is determined that the engine 30 is in a driven state. The power source state determination means 108 outputs a control command to the solenoid valve SL for switching from slip to lock-up on by the lock-up clutch control means 102, and the lock-up clutch 34 is When it is determined that the lockup control is being executed, when the elapsed time determination unit 114 determines that the elapsed time t _OFF is less than the predetermined time t _OFF ^*, it is determined that the engine 30 is in a driving state. When the elapsed time determination unit 114 determines that the elapsed time t _OFF is equal to or longer than the predetermined time t _OFF ^*, it is determined that the engine 30 is in a driven state.

FIG. 14 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device 100, that is, a mode of reducing the operating hydraulic pressure of the first friction engagement element at the time of power-off upshift, for example, several msec. It is repeatedly executed with an extremely short cycle time of about several tens of milliseconds. FIG. 14 shows another embodiment corresponding to FIG. 8 and FIG. 11, and based on the determination result of whether or not the lock-up control executed at SC1 ⁺ is being executed, whether the engine 30 is in the driving state or not. Since the point of switching the method for determining whether or not the driving state is added is particularly different from those in FIGS. 8 and 11, this difference is mainly described in the flowchart of FIG.

  FIG. 15 is a time chart for explaining the control operation shown in the flowchart of FIG. 14, which is an example when the lock-up control is being executed, and corresponds to FIG. 9 and FIG. 12. FIG. 9 is a time chart for explaining the control operation shown in the flowchart of FIG. 14, and is also an example when the lock-up clutch 34 is being released.

  First, at SC1 corresponding to the inertia running determination means 106 and the shift control means 104, it is determined whether or not it is time to start shifting of the power-off upshift. SC1 indicates a case where it is already determined that the power-off upshift is started. If it is determined that it is not at the time of starting the power-off upshift, this routine is terminated.

T ₀ point of Figure 15 shows that the coasting of the accelerator-off is determined. Further, t ₁ point is determined 3 speed during coasting → 4 gear upshift (first gear), t ₄ when fourth speed → 5-speed up-shift during coasting (second shift) is determined It is shown that.

Next, at SC1 ⁺ corresponding to the lockup-in-progress determination means 116, the solenoid valve SL output to the hydraulic control circuit 50 for switching the lockup clutch 34 by the lockup clutch control means 102 from slip to lockup on. Based on the control command, it is determined whether or not the lockup clutch 34 is performing lockup control at the start of shifting of the power-off upshift.

The embodiment of FIG. 15 shows that the engine speed _NE and the turbine speed _NT coincide with each other because the lockup clutch 34 is locked on. The lock-up clutch 34 at time point t ₁ and t ₄ time is determined to be in lock-up control execution.

Embodiment of FIG. 9 because the lock-up clutch 34 is being released, the lock-up clutch 34 is determined to be in the release at time point t ₁ and t ₄ time.

When the determination of SC1 ⁺ is affirmed, the accelerator off is performed in order to determine whether the engine 30 is in the driven state or the driven state in SC2B corresponding to the power source state determining unit 108 (elapsed time determining unit 114). It is determined whether or not the elapsed time t _OFF from the time is equal to or longer than the predetermined time t _OFF ^* .

At time t _{1 in} FIG. 15, it is determined that the elapsed time t _OFF since the accelerator is off is less than the predetermined time t _OFF ^{* and} it is determined that the engine 30 is in a driving state, and at time t ₄ , the elapsed time t after the accelerator is off. _This indicates that it is determined that _OFF is equal to or longer than the predetermined time t _OFF ^* and the engine 30 is determined to be in a driven state.

When the determination of SC1 ⁺ is negative, in SC2A corresponding to the power source state determination means 108 (rotational speed difference determination means 110), it is determined whether the engine 30 is in a driven state or a driven state. It is determined whether or not the speed difference ΔN is less than a predetermined rotational speed ΔN ^* .

  If the determination of SC2A is negative or the determination of SC2B is negative, the engine 30 is in a driving state, so in SC3 corresponding to the hydraulic pressure decrease control means 112, the first friction engagement element is quickly The immediate drain hydraulic control is released.

Time point t ₁ in FIG. 15, as the working oil pressure of the brake B3 it is quickly reduced, indicating that the immediately drain the hydraulic control is allowed to execute.

  If the determination of SC2A is affirmed or if the determination of SC2B is affirmative, the engine 30 is in a driven state, so in SC4 corresponding to the hydraulic pressure reduction control means 112, the first friction engagement element is Sweep drain hydraulic control that is gradually released is executed.

T ₄ time of FIG. 15 shows that the hydraulic pressure of the clutch C1 is relatively gently to be reduced, the sweep drain hydraulic control is allowed to execute. Thus, rapidly changing toward the immediate drain control is executed by t ₄ time to output torque T _OUT at t ₅ when a negative value at t ₄ time as in the conventional example shown by the broken line in 0N · m In comparison with this, the output torque T _OUT changes gradually from a negative value toward 0 N · m as shown from the time t _{4 to the} time t ₅ ′.

As described above, according to the present embodiment, the hydraulic pressure reduction control unit 112 is configured to reduce the operating hydraulic pressure of the first friction engagement element during the power-off upshift based on the determination result by the power source state determination unit 108. Therefore, at the time of power-off upshifting, the lengthening of the shift time when the engine 30 is in the driving state is suppressed, and the first friction engagement element is released when the engine 30 is in the driven state. The change in the output torque T _OUT of the automatic transmission 10 from the negative value to 0 N · m due to the rapid decrease in the hydraulic pressure of the first friction engagement element as in the engine 30 drive state. In comparison, drivability is improved because it is suppressed.

Further, according to this embodiment, when the lockup clutch 34 is released by the power source state determination means 108, the rotational speed difference ΔN (= N _E −) between the engine rotational speed _NE and the input shaft rotational speed N _IN. N _T ), it is properly determined whether the engine 30 is in a driven state or a driven state. On the other hand, when the lockup clutch 34 is engaged, the elapsed time t _OFF from the start of inertial traveling of the vehicle, that is, the accelerator is off. It is appropriately determined whether the engine 30 is in a driven state or a driven state based on the elapsed time t _OFF from. In this way, it is properly determined whether the engine 30 is in the driven state or the driven state regardless of whether or not the lockup clutch 34 is engaged.

In the third embodiment, the power source state determination means 108 determines whether the engine 30 is in a driven state or a driven state based on the rotational speed difference ΔN when the lockup clutch 34 is released, while the lockup clutch 34 When 34 includes the slip state and is engaged, it is determined whether the engine 30 is in the driven state or the driven state based on the elapsed time t _OFF from the start of inertial running of the vehicle.

By the way, when it is determined that the lock-up clutch 34 is performing the lock-up control, it includes a transitional state from the lock-up off, and particularly in the slip state in which the feedback control is performed, the engine speed _NE Or the turbine rotational speed _NT may be in an unstable state, and even if the elapsed time determination unit 114 determines that the elapsed time t _OFF is less than the predetermined time t _OFF ^* , the engine 30 is uniform. May not be driven.

Therefore, in this embodiment, the method for determining whether the engine 30 is in the driven state or the driven state is switched based on whether or not the lockup clutch 34 is executing the lockup control at the start of the power-off upshift. Is the same as that of the third embodiment, but the power source state determination means 108 determines that the elapsed time t _OFF from the start of coasting of the vehicle when the lock-up clutch 34 is engaged is a predetermined time t _OFF ^*. If it has not elapsed, it is further determined whether the engine 30 is in a driven state or a driven state based on the rotational speed difference ΔN.

Specifically, in FIG. 13, in addition to the function in the third embodiment, the power source state determination unit 108 determines that the lockup clutch 34 is performing lockup control by the lockup state determination unit 116. When the elapsed time determining means 114 determines that the elapsed time t _OFF is less than the predetermined time t _OFF ^* , the rotational speed difference determining means 110 determines that the rotational speed difference ΔN is greater than or equal to the predetermined rotational speed ΔN ^* . When it is determined that the engine 30 is in a driving state, it is determined that the engine 30 is in a driving state. On the other hand, when the rotation speed difference determination unit 110 determines that the rotation speed difference ΔN is less than the predetermined rotation speed ΔN ^* , the engine 30 is covered. Judged to be in a driving state.

FIG. 16 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device 100, that is, a mode for reducing the operating hydraulic pressure of the first friction engagement element at the time of power-off upshift, for example, several msec. It is repeatedly executed with an extremely short cycle time of about several tens of milliseconds. FIG. 16 shows another embodiment corresponding to FIG. 14 in the case where the determination as to whether or not the elapsed time t _OFF from the accelerator off executed in SD2B is equal to or longer than the predetermined time t _OFF ^* is denied. Further, it is particularly different in that it is determined whether or not the rotational speed difference ΔN is less than the predetermined rotational speed ΔN ^* in SD2A when the determination in SC2B of FIG. 14 is negative. Therefore, this difference will be mainly described in the flowchart of FIG.

  First, in SD1 corresponding to the inertia running determination means 106 and the shift control means 104, it is determined whether or not it is time to start shifting of the power-off upshift. SD1 indicates a case where it is already determined that the power-off upshift is started. If it is determined that it is not at the time of starting the power-off upshift, this routine is terminated.

Next, in SD1 ⁺ corresponding to the lockup in-progress determination means 116, it is determined whether or not the lockup clutch 34 is executing lockup control at the start of shifting of the power-off upshift.

If the determination of SD1 ⁺ is affirmative, whether or not the elapsed time t _OFF since the accelerator is off is equal to or longer than the predetermined time t _OFF ^* in SD2B corresponding to the power source state determination means 108 (elapsed time determination means 114). Is determined.

If the determination of SD1 ⁺ is negative or the determination of SD2B is negative, the rotational speed difference ΔN is a predetermined rotation in SD2A corresponding to the power source state determination means 108 (rotational speed difference determination means 110). It is determined whether the speed is less than ΔN ^* .

  If the determination of SD2A is negative, the engine 30 is in a driving state, and therefore, in SD3 corresponding to the hydraulic pressure lowering control unit 112, immediate drain hydraulic control in which the first friction engagement element is quickly released is executed. It is done.

If it will be described with reference to FIG. 15, when t ₁ elapsed time t _OFF of the accelerator-off at point is determined to be less than the predetermined time t _OFF ^* and the rotational speed difference .DELTA.N is at a predetermined rotational speed .DELTA.N ^* or It is determined that the engine 30 is in a driving state.

  If the determination of SD2A is affirmed or if the determination of SD2B is affirmative, the engine 30 is in a driven state, so in SD4 corresponding to the hydraulic pressure decrease control means 112, the first friction engagement element is Sweep drain hydraulic control that is gradually released is executed.

Thus, as in the t ₄ time points Although not shown FIG. 15, the sweep drain hydraulic control as the working oil pressure of the clutch C1 is lowered relatively slowly is caused to run, the output as in the prior art compared to the torque T _OUT changes rapidly towards a negative value 0N · m, changes gently towards the output torque T _OUT is from a negative value to 0N · m.

As described above, according to the present embodiment, the hydraulic pressure reduction control unit 112 is configured to reduce the operating hydraulic pressure of the first friction engagement element during the power-off upshift based on the determination result by the power source state determination unit 108. Therefore, at the time of power-off upshifting, the lengthening of the shift time when the engine 30 is in the driving state is suppressed, and the first friction engagement element is released when the engine 30 is in the driven state. The change in the output torque T _OUT of the automatic transmission 10 from the negative value to 0 N · m due to the rapid decrease in the hydraulic pressure of the first friction engagement element as in the engine 30 drive state. In comparison, drivability is improved because it is suppressed.

Further, according to this embodiment, when the lock-up clutch 34 is engaged and the elapsed time t _OFF from the start of inertial traveling of the vehicle has not passed the predetermined time t _OFF ^* , the power source Additionally or driven state engine 30 or the driving state based on the rotational speed difference ΔN between the input shaft rotational speed N _iN and the engine rotational speed N _E by the state determination unit 108 is appropriately determined. Further, when the elapsed time t _OFF has passed the predetermined time t _OFF ^* , the rotational speed difference ΔN is stable, so that the driven state is reliably determined.

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

For example, in the above-described embodiment, the power source state determination unit 108 determines that the rotational speed difference ΔN (= N _E −N _T ) between the engine rotational speed _NE and the turbine rotational speed N _T (input shaft rotational speed N _IN ). While the engine 30 based on whether or not a predetermined rotational speed .DELTA.N ^* above determines whether the driven state or driving state, and simply the engine rotational speed N _E and the turbine rotational speed N _T without using the predetermined rotational speed .DELTA.N ^* And the engine 30 may be determined to be in a driven state or a driven state based on the comparison result. Further, the power source state determination means 108 may make a prediction determination as to whether the engine 30 is in a driven state or a driven state based on the rotational speed ΔN and the rate of change thereof. Further, the power source state determination means 108 determines whether the engine 30 is based on the sign of the actual torque detected by a torque sensor provided on the rotating shaft of the power transmission path, such as the engine crankshaft, the input shaft 22, the axle 44, or the like. It may be determined whether the driving state or the driven state.

Further, in the above-described embodiment, the immediate drain hydraulic pressure control by the shift control means 104 outputs a hydraulic pressure command from the maximum value MAX to the minimum value MIN at a stretch, and the sweep drain hydraulic pressure control is performed at a predetermined rate from the maximum value MAX. Although the hydraulic pressure command for outputting the minimum value MIN while gradually decreasing is output, the decrease in the hydraulic pressure of the first friction engagement element at the time of the upshift by the sweep drain hydraulic pressure control is immediately increased by the hydraulic pressure control by the drain hydraulic pressure control. The immediate drain hydraulic pressure control by the shift control means 104 outputs a hydraulic pressure command for making the minimum value MIN while gradually decreasing from the maximum value MAX at a predetermined rate. Also good. Even in this case, at the time of power-off upshifting, the lengthening of the shift time when the engine 30 is in the driven state is suppressed, and the first friction engagement element is released when the engine 30 is in the driven state. Accordingly, the change of the output torque T _OUT from a negative value to 0 N · m is suppressed as compared with the case where the operating hydraulic pressure of the first friction engagement element is quickly reduced as in the case where the engine 30 is in the driving state. Is done.

  Moreover, although the above-mentioned Example was applied about the upshift of 2 steps | paragraphs, it can be applied also to the upshift of 1 step | paragraph or 3 steps | paragraphs or more.

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

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a vehicle automatic transmission to which the present invention is applied. FIG. 2 is an operation chart for explaining a combination of operations of the friction engagement device when a plurality of shift stages of the vehicle automatic transmission of FIG. 1 are established. It is a block diagram explaining the principal part of the control system with which the automatic transmission for vehicles of FIG. 1 is provided. FIG. 4 is a circuit diagram relating to a linear solenoid valve that controls the operation of each hydraulic actuator of clutches C1 and C2 and brakes B1 to B3 in the hydraulic control circuit of FIG. 3. It is a functional block diagram explaining the principal part of the control function of the electronic control apparatus of FIG. It is a figure explaining an example of the lockup area | region diagram used for control of the lockup clutch in a torque converter. It is a figure which shows an example of the shift map used in the shift control of an automatic transmission. FIG. 6 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device of FIG. 5, that is, a mode for reducing the hydraulic pressure of the first friction engagement element at the time of power-off upshift. It is a time chart explaining the control action shown in the flowchart of FIG. Moreover, it is a time chart explaining the control action shown in the flowchart of FIG. 14, and is also an example when the lockup clutch is being released. It is a functional block diagram explaining the principal part of the control function of the electronic controller of FIG. 3, Comprising: It is a figure equivalent to FIG. FIG. 9 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device of FIG. 10, that is, a mode for reducing the hydraulic pressure of the first friction engagement element at the time of power-off upshifting, corresponding to FIG. 8. This is another embodiment. It is a time chart explaining the control action shown in the flowchart of FIG. 11, and is a figure corresponding to FIG. It is a functional block diagram explaining the principal part of the control function of the electronic controller of FIG. 3, Comprising: It is a figure equivalent to FIG. FIG. 14 is a flowchart for explaining a control operation for changing a main part of the control operation of the electronic control device of FIG. 13, that is, a mode for reducing the operating hydraulic pressure of the first friction engagement element at the time of power-off upshifting. This is another embodiment corresponding to 11. FIG. 15 is a time chart for explaining the control operation shown in the flowchart of FIG. 14, which is an example when lockup control is being executed, and is a diagram corresponding to FIG. 9 and FIG. 12. Moreover, it is a figure used also for description of the control action shown to the flowchart of FIG. FIG. 13 shows another embodiment of the electronic control unit shown in FIG. 13, in which the main part of the control operation, that is, the mode of reducing the hydraulic pressure of the first friction engagement element during the power-off upshift is changed. It is a flowchart explaining a control action. 10 is a time chart showing an example of hydraulic control operation of engagement (apply) and release (drain) of a release-side friction engagement device and an engagement-side friction engagement device at the time of power-off upshift in the related art.

Explanation of symbols

10: Vehicle automatic transmission 30: Engine (power source)
32: Torque converter (fluid transmission)
34: Lock-up clutch 100: Electronic control device (hydraulic control device)
108: Power source state determination means 112: Hydraulic pressure drop control means C1, C2: Clutch (friction engagement element)
B1, B2, B3: Brake (friction engagement element)

Claims (4)

During inertial running of the vehicle, the first frictional engagement element is decreased to release the first frictional engagement element and the second frictional engagement element is increased to increase the second frictional engagement element. A hydraulic control device for a vehicle automatic transmission that performs a power-off upshift by engaging elements,
Power source state determination means for determining whether the power source at the start of shifting of the power-off upshift is a driving state or a driven state;
When it is determined that the power source is in the driving state, the hydraulic pressure of the first friction engagement element is relatively quickly reduced, while when it is determined that the power source is in the driven state, the power source The power source so that the hydraulic pressure of the first frictional engagement element is decreased relatively slowly until the first frictional engagement element is released compared to when it is determined that is in a driving state . And a hydraulic pressure lowering control unit that changes a mode of lowering the operating hydraulic pressure of the first friction engagement element at the time of the power-off upshift based on a determination result by the state determination unit. Hydraulic control device for transmission. The vehicle automatic transmission is configured to transmit the output of the power source that is input via a fluid transmission device to drive wheels,
The power source state determining means determines whether the power source is in a driven state or a driven state based on a rotational speed difference between an output shaft rotational speed of the power source and an input shaft rotational speed of the vehicle automatic transmission. The hydraulic control device for an automatic transmission for a vehicle according to claim 1.   2. The hydraulic control for an automatic transmission for a vehicle according to claim 1, wherein the power source state determining means determines whether the power source is in a driven state or a driven state based on an elapsed time from the start of inertial running of the vehicle. apparatus. The vehicle automatic transmission is configured to transmit the output of the power source that is input via a fluid transmission device with a lock-up clutch to drive wheels,
The power source state determining means is configured to determine whether the power source is based on a rotational speed difference between an output shaft rotational speed of the power source and an input shaft rotational speed of the vehicle automatic transmission when the lockup clutch is released. While determining whether the drive state is driven or not, while the lock-up clutch is engaged, it is determined whether the power source is in the drive state or the driven state based on the elapsed time from the start of inertial running of the vehicle. The hydraulic control device for an automatic transmission for a vehicle according to claim 1.

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