JP2011190864A - Control device of automatic transmission - Google Patents

Abstract

A control device for an automatic transmission capable of reducing judder when a hydraulic friction engagement device is engaged is provided. A clutch C1, which is a starting clutch by a hydraulic control means (SA5), is provided. By performing at least one of the control of the engagement hydraulic pressure P _{C1 and} the control of the input torque of the clutch C1 by the input torque control means 126 (SA6), the change gradient of the friction coefficient μ of the clutch C1 with respect to the differential rotation V is increased. Since the value Δμ / ΔV is equal to or greater than the predetermined value Gth, it is possible to reduce the shudder generated based on the value Δμ / ΔV of the change gradient with respect to the differential rotation V of the friction coefficient μ.
[Selection] Figure 11

Description

  The present invention relates to a control device for an automatic transmission, and more particularly to a technique for reducing shudder when a hydraulic friction engagement device is engaged.

  In an automatic transmission, a hydraulic friction engagement device is widely used. By switching between the engaged state and the released state of the hydraulic friction engagement device, it is possible to switch between the power transmission state and the power cutoff state in the power transmission path. When the hydraulic friction engagement device is changed from the released state to the engaged state, an engagement shock or a shudder (vibration / noise due to friction and vibration characteristics) may occur in the engagement process. The occurrence of such an engagement shock or shudder gives the driver a sense of incongruity, that is, deteriorates drivability.

  In contrast to the generation of such a shudder, conventionally, the composition of the friction material that is difficult to generate a shudder, the development of a manufacturing method, or the change of the structure of the shudder friction engagement device, for example, by increasing damping, etc. Etc. were performed. Further, as a method for reducing the shudder by the control, for example, a method of prohibiting the engagement control when the occurrence of the shudder is detected has been taken.

  In Patent Document 1, as one method for controlling the friction engagement device, a differential rotation of the friction engagement device is calculated, a state value S (Sommerfeld number) is calculated, and the clutch disk dynamic friction coefficient is calculated from the calculated state value S. A control device for an automatic transmission that searches and calculates a clutch disc pressing force by hydraulic pressure from a target clutch torque and the like, and calculates an amount of hydraulic pressure to be supplied to the clutch is disclosed.

JP 2001-165301 A

  According to the method disclosed in Patent Document 1, it is possible to improve the control accuracy of the engagement hydraulic pressure in the engagement of the friction engagement device. However, it is required to improve drivability by further contrivance.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a control device for an automatic transmission that can reduce judder during engagement of a hydraulic friction engagement device. There is.

  In order to achieve this object, the invention according to claim 1 is: (a) a control device for an automatic transmission having a hydraulic friction engagement device, and (b) when the hydraulic friction engagement device is engaged. A friction coefficient of the hydraulic friction engagement device is calculated on the basis of the differential rotation, pressing pressure, and temperature of the hydraulic friction engagement device, and (c) a change in the calculated friction coefficient with respect to the differential rotation. It is characterized in that at least one of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is controlled so that the gradient becomes a predetermined value or more.

  In the invention according to claim 2, the control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed when a gradient of change of the friction coefficient with respect to the differential rotation is a predetermined value or less. It is characterized by.

  The invention according to claim 3 is characterized in that the control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed in the return control from the neutral control and the idle stop return control.

  According to the first aspect of the present invention, by controlling at least one of the engagement hydraulic pressure and the input torque, the value of the change gradient of the friction coefficient with respect to the differential rotation is set to be equal to or greater than the predetermined value. Therefore, it is possible to reduce the shudder that is generated based on the value of the gradient of the friction coefficient with respect to the differential rotation.

  According to the invention of claim 2, when the change gradient of the friction coefficient with respect to the differential rotation is equal to or less than a predetermined value, control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed. Therefore, it is possible to reduce the shudder that is generated based on the value of the gradient of the friction coefficient with respect to the differential rotation.

  According to the invention of claim 3, since the control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed in the return control from the neutral control, the vehicle speed is very small, and the driver However, it is possible to reduce the shudder that is generated based on the value of the change gradient with respect to the differential rotation of the friction coefficient in a vehicle state in which a sense of discomfort tends to be felt.

  Preferably, the control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed in the idle stop return control. Therefore, in the vehicle state where the vehicle speed is very low and the driver tends to feel uncomfortable, the friction is reduced. The shudder generated based on the value of the change gradient with respect to the differential rotation of the coefficient can be reduced.

  Preferably, the engagement hydraulic pressure is controlled based on the differential rotation stored in advance and the relationship of the friction coefficient of the hydraulic friction engagement device with respect to the engagement hydraulic pressure. In this way, the differential rotation can be changed by controlling the engagement hydraulic pressure, and the shudder generated based on the value of the change gradient of the friction coefficient with respect to the differential rotation can be reduced.

  Further preferably, the control of the input torque is performed based on a relationship between the differential rotation stored in advance and a friction coefficient of the hydraulic friction engagement device with respect to the input torque. In this way, the differential rotation can be changed by controlling the input torque, and the shudder generated based on the value of the gradient of the friction coefficient with respect to the differential rotation can be reduced.

1 is a skeleton diagram of a vehicle automatic transmission that is a part of a vehicle power transmission device to which the present invention is applied. FIG. FIG. 2 is an operation table for explaining an operation state of a friction engagement element, that is, a friction engagement device when a plurality of shift speeds are established in the automatic transmission of FIG. 1. FIG. 2 is a block diagram illustrating a schematic configuration of a main part of a control system provided in a vehicle for controlling the automatic transmission and the like of FIG. 1 and a power transmission system from an engine to driving wheels. FIG. 4 is a circuit diagram relating to a linear solenoid valve that controls the operation of clutch and brake hydraulic actuators (hydraulic cylinders) in the hydraulic control circuit of FIG. 3. It is a functional block diagram explaining the principal part of the control function by an electronic control apparatus. FIG. 7 is a shift diagram for determining a shift based on an actual vehicle speed and an accelerator opening from a relationship stored in advance with the vehicle speed and the accelerator opening as variables. It is a figure showing the relationship of the friction coefficient with respect to the differential rotation of a clutch, and engagement hydraulic pressure. It is a figure showing the relationship of the friction coefficient with respect to the differential rotation of a clutch, and hydraulic oil temperature. It is a figure explaining the control action of a hydraulic control circuit, Comprising: It is a figure corresponding to the relationship shown by FIG. It is a figure explaining the control action of an input torque control means, Comprising: It is a figure corresponding to the relationship shown by FIG. It is a time chart for demonstrating the control action | operation in case cancellation | release control from neutral control in a present Example is performed.

  Hereinafter, an embodiment 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 10 (hereinafter, automatic transmission 10) which is a part of a vehicular power transmission apparatus to which the present invention is applied. 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 (see FIG. 3). 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 rotation member of the engine 30, while the output rotation member 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. Particularly, since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first shift stage “1st”, only the clutch C1 is engaged and the engine brake is applied when starting (acceleration). Sometimes the clutch C1 and the brake B2 are engaged. Therefore, the so-called neutral control for suppressing the idling load of the engine 30 can be performed by setting the clutch C1 to the slipping state or the releasing state when the vehicle in which the first shift speed is established. 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 schematic configuration of a main part of a control system provided in the vehicle for controlling the automatic transmission 10 and the like of FIG. 1 and a power transmission system from the engine 30 to the drive wheels 46. .

  In FIG. 3, the electronic control unit 100 is configured to include a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. By performing signal processing according to the programmed program, output control of the engine 30, shift control of the automatic transmission 10, on / off control of the lock-up clutch 34, and the like are executed. It is divided into a shift control for controlling the linear solenoid valves SL1 to SL5 and a lock-up clutch control for controlling the linear solenoid valve SLU and the solenoid valve SL of the hydraulic control circuit 50.

For example, the electronic control unit 100 includes an accelerator opening signal indicating the accelerator opening Acc that is the operation amount of the accelerator pedal 52 detected by the accelerator opening sensor 54, and the rotation of the engine 30 detected by the engine rotation speed sensor 56. a signal indicative of the engine rotation speed N _E is a speed, a signal representing the cooling water temperature T _W of the engine 30 detected by a coolant temperature sensor 58, a signal representing the intake air quantity Q of the engine 30 detected by the intake air quantity sensor 60 , _A signal representing the intake air temperature TA detected by the intake air temperature sensor 62, a throttle opening signal representing the electronic throttle valve opening θ _TH detected by the throttle valve opening sensor 64, and a vehicle speed sensor 66 by rotational speed N _OUT ie vehicle speed signal corresponding to the vehicle speed v of the output rotary member 24, the brake Sui Operation of the foot brake pedal 68 shown in foot brake operation is a service brake, which is detected by the switch 70 (in depressing) (ON) signal representing the B _ON, the lever of the shift lever 72 detected by a lever position sensor 74 A signal representing the position (operation position, shift position) P _SH , a signal representing the turbine rotational speed N _T (= the rotational speed N _IN of the input shaft 22) detected by the turbine rotational speed sensor 76, and detected by the AT oil temperature sensor 78 A signal representing the AT oil temperature T _OIL which is the temperature of the hydraulic oil in the hydraulic control circuit 50 is supplied.

Further, the electronic control device 100 supplies a drive signal to a throttle actuator for operating the opening degree θ _TH of the electronic throttle valve, an ignition signal for instructing the ignition timing of the engine 30, and fuel to the intake pipe or cylinder of the engine 30. A fuel supply amount signal for controlling the fuel supply amount to the engine 30 by the fuel injection device to be stopped or stopped, a lever position P _SH display signal for operating the shift indicator, and a hydraulic control for switching the gear stage of the automatic transmission 10 A signal for controlling the shift solenoid that drives the shift valve in the circuit 50, a command signal for driving the linear solenoid valve for controlling the line pressure, a linear solenoid valve for controlling the engagement, release, and slip amount of the lockup clutch 34 A command signal or the like for driving is output.

  The shift lever 72 is disposed, for example, in the vicinity of the driver's seat, and is manually operated to five lever positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It has come to be.

  The “P” position (range) releases the power transmission path in the automatic transmission 10, that is, enters a neutral state (neutral state) in which the power transmission in the automatic transmission 10 is interrupted, and mechanically rotates the output by the mechanical parking mechanism. This is a parking position (position) for preventing (locking) the rotation of the member 24, and the “R” position is a reverse travel position (position) for reversing the rotation direction of the output rotation member 24 of the automatic transmission 10. The “N” position is a neutral position (position) for achieving a neutral state in which power transmission in the automatic transmission 10 is interrupted, and the “D” position is a shift range that allows the automatic transmission 10 to shift. In (D range), the forward travel position is set to execute the automatic shift control using all the forward gears from the first gear stage “1st” to the sixth gear stage “6th”. The “S” position is a forward travel that allows manual shifting by switching between multiple types of shift ranges that limit the range of gear change, that is, multiple types of shift ranges with different gears on the high vehicle speed side. Position.

In this “S” position, the shift range is shifted to the down side every time the shift lever 72 is operated, the “+” position as the lever position P _SH for shifting the shift range to the up side every time the shift lever 72 is operated. A “−” position is provided as a lever position P _SH for the movement. For example, in the “S” position, any of the “6” range to the “L” range is changed according to the operation of the shift lever 72 to the “+” position or the “−” position. The “L” range at the “S” position is also an engine brake range for obtaining a further engine braking effect by engaging the brake B2 at the first gear stage “1st”.

  The “D” position is an automatic transmission mode that is a control mode in which automatic transmission control is executed in the range of the first to sixth gears, for example, as shown in FIG. The “S” position is a lever position to be selected. In the “S” position, automatic shift control is executed in a range not exceeding the highest speed gear of each shift range of the automatic transmission 10 and the shift changed by manual operation of the shift lever 72 It is also a lever position for selecting a manual shift mode that is a control mode in which the manual shift control is executed based on the range (that is, the highest speed gear stage).

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, each hydraulic actuator A _C1 , A _C2 , A _B1 , A _B2 , A _B3 has a line oil pressure PL corresponding to a command signal from the electronic control unit 100 by linear solenoid valves SL1 to SL5. 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 3rd speed to the 4th speed, the brake B3 is released and the clutch C2 is engaged, so that the release transient hydraulic pressure of the brake B3 is suppressed so as to suppress the shift shock. And the engagement hydraulic pressure of the clutch C2 are appropriately 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 engine output control means 102 controls opening and closing of an electronic throttle valve by a throttle actuator for throttle control, controls fuel injection by a fuel injection device for fuel injection control, and controls ignition timing. The output control of the engine 30 is executed by controlling the ignition timing by an ignition device such as an igniter. For example, the engine output control unit 102 drives the throttle actuator based a predetermined stored relationship of the accelerator opening signal Acc, the throttle control to increase the throttle valve opening theta _TH as the accelerator opening Acc is increased Execute. Specifically, for example, the engine output control means 102 can perform control so that the engine torque output from the engine 30 becomes the required engine torque instructed by the neutral control return means 110 described later.

  The shift control means 104 determines shift based on the actual vehicle speed v and the accelerator opening Acc from the relationship (map, shift diagram) stored in advance with the vehicle speed v and the accelerator opening Acc as variables, for example, as shown in FIG. 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. 6, the solid line is a shift line (upshift line) for determining an upshift, and the broken line is a shift line (downshift line) for determining a downshift. Further, the shift line in the shift diagram of FIG. 6 indicates whether or not the actual vehicle speed v crosses the line on the horizontal line indicating the actual accelerator opening degree Acc (%), that is, the value on which the shift on the shift line is to be executed ( This is for determining whether or not the shift point vehicle speed (vS) has been exceeded, and is also stored in advance as a series of this value vS, that is, the shift point vehicle speed.

The neutral control condition determination unit 106 determines whether or not a predetermined neutral control condition is satisfied at the travel position of the shift lever 72. The predetermined neutral control condition is, for example, that the vehicle is stopped, the accelerator pedal 52 is not depressed, and the foot brake pedal 68 is depressed. More specifically, the neutral control condition determination unit 106 determines that the vehicle speed v is equal to or less than a predetermined stop determination value and the brake switch 70 is ON B _ON , for example, when the lever position P _SH is the “D” position. In this case, it is determined that the neutral control condition is satisfied.

In addition, the neutral control condition determination unit 106 determines whether or not the predetermined neutral control condition is satisfied during the neutral control by the neutral control unit 108 to be described later, thereby releasing (ending) the neutral control. It is also a neutral control release determination means that sequentially determines whether or not, that is, sequentially determines whether or not to return from neutral control. Specifically, the neutral control condition determination unit 106 determines the start of the neutral control release when the brake switch 70 is not turned _ON during the neutral control.

  When the neutral control condition determining means 106 determines that the predetermined neutral control condition is satisfied, for example, at the “D” position of the shift lever 72, the neutral control means 108 is used to achieve the first gear. Neutral control that outputs a neutral command to put the clutch C1 that is an engagement device into a slipping state or a releasing state to the shift control means 104 so that the power transmission path including the automatic transmission 10 is in a power transmission suppression state or a power transmission cut-off state. Execute. The shift control means 104 outputs to the hydraulic control circuit 50 a control signal for reducing the engagement pressure of the clutch C1 in accordance with a predetermined pattern so that the clutch C1 is in the slip state or the release state in accordance with the neutral command. . When the power transmission in the automatic transmission 10 is suppressed or cut off (released), the torque converter 32 rotates substantially integrally and the idling load of the engine 30 is suppressed, and fuel consumption and NVH (noise / vibration / riding) are reduced. Comfort) performance is improved.

  Thus, in this neutral control, the clutch C1 is disengaged (a state just before engagement that slightly slips in engagement), for example, so that the power transmission path in the automatic transmission 10 is substantially disengaged. On the other hand, a start standby state is set in which the clutch C1 can start immediately by switching from half-engagement to engagement.

  The neutral control return means 110 is configured to change the power transmission path including the automatic transmission 10 to a power transmission enabled state when the neutral control condition determination means 106 determines that the neutral control release is started during the neutral control. A neutral control release command for increasing the torque transmission capacity of the clutch C <b> 1, which is the engaging device for the first gear stage, is output to the shift control means 104. The clutch C1 corresponds to the starting clutch of the present invention. At the time of execution of the neutral control return means 110, the clutch C1, which is an engagement device, is engaged. For example, this engagement is a torque caused by a deviation between the clutch torque at the end of engagement (clutch torque capacity) and the input torque. In order to avoid the step, the control is performed by feedback control with respect to the change amount of the target differential rotation speed.

  By the way, when the clutch C1, which is the starting clutch, is engaged, the gradient Δμ / ΔV with respect to the change amount ΔV of the difference rotational speed V of Δμ that is the change amount of the friction coefficient μ of the clutch C1 satisfies the relationship of Δμ / ΔV <0. It is known that when it is satisfied, the state of the clutch C1 becomes unstable and a shudder is generated. In order to suppress such shudder, in the engagement control of the clutch C1, control is performed so that the gradient Δμ / ΔV becomes a positive value. Note that the differential rotation V (rpm) of the clutch C1 is a difference in rotational speed between two rotating elements engaged with the clutch C1.

However, the friction coefficient μ of the clutch C1 is also affected by the pressing pressure of the clutch C1 and the oil temperature T _{OIL of the} hydraulic oil. Since this pressing pressure changes according to the engagement hydraulic pressure supplied from the hydraulic control circuit 50 for the engagement of the clutch C1, the friction coefficient μ of the clutch C1 depends on the engagement hydraulic pressure of the clutch C1. Is also affected. That is, when the engagement hydraulic pressure PC1 is changed or the hydraulic oil temperature _TOIL is changed during the engagement process, the friction coefficient of the clutch C1 is maintained even when the differential rotational speed V is the same. μ may be different.

FIG. 7 is a graph showing the relationship of the friction coefficient μ of the clutch C1 with respect to the differential rotation V (rpm) of the clutch C1 and the engagement hydraulic pressure P _C1 (Pa) of the clutch C1. In FIG. 7, lines L1 to L3 represent the relationship between the differential rotation V and the friction coefficient μ when the engagement hydraulic pressure P is constant, and among L1 to L3, L1 is when the engagement hydraulic pressure _PC1 is the smallest. Correspondingly, L3 corresponds to the case where the engagement oil pressure P is the highest, and L2 corresponds to the case between the case where the engagement oil pressure _PC1 is L1 and L3. That is, the engagement pressure _{P C1} to the corresponding engagement pressure _{P C1} to the corresponding engagement pressure _{P C1} corresponding to the case of L1 in case of P1, L2 in case of P2, L3 and P3, P1 <P2 <P3 It becomes. In FIG. 7, when the differential rotation V is constant, it represents the friction coefficient higher oil pressure P _C1 is smaller μ is large.

FIG. 8 is a graph showing the relationship of the friction coefficient μ of the clutch C1 with respect to the differential rotation V (rpm) of the clutch C1 and the oil temperature T _OIL (° C.) of the hydraulic oil of the clutch C1. In FIG. 8, lines L4 to L6 represent the relationship between the differential rotation V and the friction coefficient μ when the oil temperature T _OIL is constant. Of L4 to L6, L4 corresponds to the case where the oil temperature T _OIL is the lowest. L6 corresponds to the case where the oil temperature T _OIL is the highest, and L5 corresponds to the case between the case where the oil temperature T _OIL is L4 and L6. That is, if the oil temperature T _OIL corresponding to the case of L1 is T4, the oil temperature T _OIL corresponding to the case of L2 is T5, and the oil temperature T _OIL corresponding to the case of L3 is T6, then T4 <T5 <T6 Become. In FIG. 8, when the differential rotation V is constant, the lower the oil temperature T _OIL is, the larger the friction coefficient μ is.

As shown in FIG. 7, in the course of engagement of the clutch C1, even if the control is performed so that the gradient [Delta] [mu / [Delta] V is positive, the change in the oil pressure P _C1 is caused by some factor Unintentionally, the gradient μ changes, and as a result, the actual gradient Δμ / ΔV can be negative. In such a case, a shudder is generated. Similarly, as shown in FIG. 8, even when the control is performed so that the gradient Δμ / ΔV becomes positive in the process of engagement of the clutch C1, the change in the oil temperature T _OIL is caused by some factor. Can unintentionally change the slope μ, and as a result, the actual slope Δμ / ΔV can be negative. In such a case, a shudder is generated. For example, an arrow T indicated by a thick broken line in FIGS. 7 and 8 represents a state transition of the clutch C1. The tangent of each point on the arrow represented by the thick broken line, that is, the slope corresponds to the gradient Δμ / ΔV. Of the arrows indicated by the thick broken lines, when the gradient Δμ / ΔV <0, as indicated by the portion R surrounded by the alternate long and short dash line, the clutch C1 is in a state where a shudder can occur.

In order to solve this problem, the neutral control return means 110 of the present embodiment
Oil temperature detecting means 112, pressing oil pressure detecting means 114, differential rotation detecting means 116, storage means 118, friction coefficient calculating means 120, gradient calculating means 122, hydraulic pressure control means 124, input torque control means 126, and learning control means 130 Functionally equipped.

Among these, the oil temperature detecting means 112 detects the oil temperature T _OIL of the hydraulic oil measured by an oil temperature sensor 78 provided in the automatic transmission 10, for example.

Pressing pressure detecting means 114, by detecting the directive on engagement pressure P _C1 of the clutch C1 is a starting clutch output by the shift control means 104, for detecting the contact pressure of the clutch C1. The predetermined relationship is, for example, a relationship between the engagement hydraulic pressure PC1 of the clutch _C1 and the pressing pressure obtained experimentally or by simulation in advance, and is obtained in advance in the form of a map, a function, or a table, for example. Yes.

  The differential rotation detection means 116 detects the differential rotation of the clutch C1, which is a starting clutch. The differential rotation of the clutch C1 is the difference between the rotational speeds of the two rotating elements engaged with the clutch C1. Specifically, the differential rotation detecting means 116 is based on the input shaft rotational speed and the output shaft rotational speed of the automatic transmission 10, and based on the gear ratio of the automatic transmission 10 that is known in advance. Detect rotation. Here, the input shaft rotational speed NIN corresponds to the turbine rotational speed NT of the torque converter 32 and is detected by the turbine rotational speed sensor 76. Further, the output shaft rotational speed NOUT is detected by the vehicle speed sensor 66.

The storage unit 118 stores information necessary for executing the neutral control return unit 110 in a readable manner. As specifically illustrated in FIG. 7 example, the coefficient of friction rotation difference V in the clutch C1, the relationship and the friction coefficient μ with respect to the hydraulic P _C1, rotation difference V in the clutch C1 as shown in FIG. 8, for the oil temperature T _OIL The relationship of μ is stored in advance.

Friction coefficient calculating means 120, engaging the clutch C1 which is detected by the oil temperature _{T OIL} detecting means of the clutch C1 which is detected by the 112, that is, the oil temperature _{T OIL} of the working oil in the automatic transmission 10, the pressing pressure detecting means 114 Based on the combined hydraulic pressure P _C1 , the pressing pressure of the clutch C1, and the differential rotation V of the clutch C1 detected by the differential rotation detection unit 116, the relationship stored in the storage unit 118 in advance is applied, whereby the clutch C1 The friction coefficient μ of is calculated. Oil temperature _{T OIL} detecting means 112 detects the oil temperature _{T OIL} of the working oil of the clutch C1 by the detection of the engagement pressure _{P C1} of the clutch C1 by pressing hydraulic detection unit 114, the differential rotation V of the clutch C1 by differential rotation detecting means 116 And the calculation of the friction coefficient μ of the clutch C1 by the friction coefficient calculation means 120 are repeated at a preset interval such as several tens of milliseconds.

  The gradient calculating means 122 calculates the gradient of the change amount Δμ per minute time of the friction coefficient μ of the clutch C1 with respect to the change amount ΔV per minute time of the differential rotation V of the clutch C1, that is, Δμ / ΔV. As described above, when the detection of the differential rotation V of the clutch C1 by the differential rotation detection means 116 and the calculation of the friction coefficient μ of the clutch C1 by the friction coefficient calculation means 120 are repeatedly performed at a preset interval Δt. The amount of change per minute time can be expressed by the difference in the two most recent detections and calculations. That is, assuming that the time t when the friction coefficient μ of the clutch C1 is most recently calculated by the friction coefficient calculating means 120 is t1, the change amount Δμ of the friction coefficient μ per minute time is Δμ = μ (t = t1). )-[Mu] (t = t1- [Delta] t). The same applies to the change amount ΔV per minute time of the differential rotation V.

The hydraulic pressure control unit 124 controls the clutch C1 so that the gradient Δμ / ΔV becomes larger than the predetermined value Gth when the value of the gradient Δμ / ΔV detected by the gradient calculating unit 112 becomes equal to or less than the predetermined value Gth. The engagement hydraulic pressure _PC1 is controlled. Specifically, for example, the hydraulic control means 124 is engaged so as to have a predetermined pattern as an engagement hydraulic pressure P _C1 of the clutch C1 that is a starting clutch with respect to the passage of time from the start time of the release control from the neutral control. When controlling the combined hydraulic pressure P _C1 and controlling the gradient Δμ / ΔV, the engagement hydraulic pressure P _C1 is controlled via the shift control means 104 and the hydraulic control circuit 50 so as to be different from the pattern. Do. Control of the engagement pressure P _C1, compared engaging pressure P _C1 of the clutch C1 based on the pattern, calculates a correction value [Delta] P _C1 necessary for gradient [Delta] [mu / [Delta] V is greater than the predetermined value Gth, the It is performed by correcting the correction value [Delta] P _C1 by engaging pressure _{P C1.} Here, the magnitude of the predetermined value Gth is set experimentally or by simulation as a value that can sufficiently ensure the damping performance of the shudder in the clutch C1. The value that can sufficiently secure the judder damping performance is specifically, for example, the clutch C1, the shudder does not occur or even if it occurs, the shudder is sufficient, specifically, for example, the passenger feels uncomfortable. It is a value that can be attenuated to the extent that it is not given.

Figure 9 is a view for explaining an example of control operation of the engagement pressure P _C1 of the clutch C1 by the hydraulic control unit 124. FIG. 9 is a diagram in which the horizontal axis represents the differential rotation V (rpm) of the clutch C1 and the vertical axis represents the relationship of the friction coefficient μ of the clutch _C1 for each engagement oil pressure P _C1 . FIG. When the state of the clutch C1 changes from the state represented by the point S1 in FIG. 9 (hereinafter referred to as “state S1”) to the state represented by the point S2 in FIG. 9 (hereinafter referred to as “state S2”), the gradient changes to G1. The calculating means 122 calculates the gradient Δμ / ΔV in the change G1 from the state S1 to the state S2. Since the calculated gradient Δμ / ΔV is larger than the predetermined value Gth, the engagement hydraulic pressure P _C1 is not controlled by the hydraulic pressure control means 124.

Next, consider a case G2 in which the state of the clutch C1 changes from the state S2 to the state represented by the point S3 in FIG. 9 (hereinafter referred to as “state S3”). At this time, the engaging pressure _{P C1} of the clutch C1 is changing. Therefore, it is the slope [Delta] [mu / [Delta] V, which is calculated by the gradient calculation unit 122 is less than the predetermined value Gth, the control of the engagement pressure P _C1 by the hydraulic pressure control unit 124 is performed. Specifically, the hydraulic control unit 124 calculates a correction value [Delta] P _C1 of the engagement pressure _{P C1} of the clutch C1, it corrects the engagement pressure _{P C1.} As a result of the correction, the state of the clutch C1 is not the state S3 but G3 which changes to the state represented by the point S3 ′ in FIG. 9 (hereinafter referred to as “state S3 ′”), and the gradient Δμ / ΔV is larger than the predetermined value Gth. Accordingly, in the clutch C1, no shudder is generated or even if it occurs, the shudder can be sufficiently damped.

The input torque control means 126 allows the clutch so that the gradient Δμ / ΔV becomes larger than the predetermined value Gth when the value of the gradient Δμ / ΔV detected by the gradient calculating means 122 becomes equal to or less than the predetermined value Gth. The differential rotation V of C1 is controlled. Specifically, for example, the input torque control means 126 outputs to the engine output control means 102 so as to have a predetermined pattern as the engine output with respect to the passage of time from the start time of the release control from the neutral control. And when the gradient Δμ / ΔV is less than or equal to the predetermined value Gth, by causing the engine output control means 102 to control the output of the engine 30 so as to be different from the pattern, The gradient Δμ / ΔV is controlled, that is, the differential rotation V of the clutch C1 is controlled. For example, the differential rotation V of the clutch C1 is controlled by increasing / decreasing the output of the engine 30 from the pattern and increasing / decreasing the input torque of the automatic transmission 10. For example, the input torque control means 126 calculates the correction value V _rev for the differential rotation V so that the gradient Δμ / ΔV becomes the change amount ΔV of the differential rotation necessary for the gradient Δμ / ΔV to be larger than the predetermined value Gth, and the correction is performed. This is done by correcting the differential rotation V by the value V _rev . The relationship between the correction value V _rev of the differential rotation V and the increase / decrease in the output of the engine 30 to be controlled is stored in advance in consideration of, for example, the vehicle state and the correction value V of the differential rotation V to be controlled. It is only necessary to be able to determine an output command of the engine 30 based on _rev , for example, a correction amount of the throttle opening.

Figure 10 is a diagram for explaining an example of control operation of the engagement pressure P _C1 of the clutch C1 by the input torque control means 126. FIG. 10 is a diagram in which the horizontal axis represents the differential rotation V (rpm) of the clutch C1 and the vertical axis represents the relationship of the friction coefficient μ of the clutch C1 for each hydraulic oil temperature T _OIL . FIG. When the state of the clutch C1 changes from the state represented by the point S11 in the figure (hereinafter referred to as “state S11”) to the state represented by the point S12 in the figure (hereinafter referred to as “state S12”), the gradient calculating means is changed to G11. 122 calculates the gradient Δμ / ΔV in the change G11 from the state S11 to the state S12. Since the calculated gradient Δμ / ΔV is larger than the predetermined value Gth, the differential rotation V of the clutch C1 is not controlled by the control of the output of the engine 30 by the input torque control means 126.

Next, consider a case G12 where the state of the clutch C1 changes from the state S12 to the state represented by the point S13 in FIG. 10 (hereinafter referred to as “state S13”). At this time, the hydraulic oil temperature _TOIL of the automatic transmission 10 of the clutch C1 is changing. Therefore, the gradient Δμ / ΔV calculated by the gradient calculating means 122 becomes equal to or less than the predetermined value Gth, the output of the engine 30 is controlled by the input torque control means 126, and the differential rotation V of the clutch C1 is controlled. Specifically, the input torque hydraulic pressure control means 126 calculates a correction amount V _rev for the differential rotation V and instructs the engine output control means 102 to increase or decrease the output of the engine 30 corresponding to the correction amount V _rev. . As a result of the correction, the state of the clutch C1 is not the state S13 but G13 which changes to a state represented by a point S13 ′ in FIG. 10 (hereinafter referred to as “state S13 ′”), and the gradient Δμ / ΔV is larger than the predetermined value Gth. Accordingly, in the clutch C1, no shudder is generated or even if it occurs, the shudder can be sufficiently damped.

The learning control means 130 performs learning control based on the control results for the hydraulic pressure control means 124 and the input torque control means 126. Specifically, the pattern predetermined as the time change of the engagement hydraulic pressure P _C1 with the passage of time is changed based on the correction value ΔP _C1 of the engagement hydraulic pressure P _C1 performed in the hydraulic control means 124. . More specifically, such as by offset the pattern only _C1 minutes the correction value [Delta] P, performs learning control. Further, the learning control is also performed by changing the pattern predetermined as the time change of the engine output with the passage of time by changing the engine output based on the correction value of the engine output similarly performed by the input torque control means 126. Do.

  FIG. 11 is a flowchart for explaining a main part of the control operation in the engagement of the starting clutch C1 in the release control from the neutral control, which is an example of the control operation of the neutral control return means 110, which is an embodiment of the present invention. For example, it is repeatedly executed with an extremely short cycle time of about several milliseconds to several tens of milliseconds. This flowchart is executed, for example, when a determination is made to cancel the neutral control in a vehicle in which the neutral control is being executed.

First, in SA1 corresponding to the oil temperature detecting means 112, the pressing pressure detecting means 114, and the differential rotation detecting means 116, the hydraulic oil temperature T _OIL of the automatic transmission 10, the pressing pressure of the clutch C1, the differential rotation of the clutch C1. Each V is detected.

Subsequently, in SA2 corresponding to the friction coefficient calculating means 120, the hydraulic oil temperature T _{OIL of} the automatic transmission 10 detected in SA1, the pressing pressure of the clutch C1, and the differential rotation V of the clutch C1 are stored in advance. relationships and the differential rotation V, the coefficient of friction for the hydraulic P _C1 mu in the clutch C1 has, rotation difference V in the clutch C1, based on the relationship of the friction coefficient mu for the oil temperature T _oIL, the friction coefficient of the clutch C1 mu is calculated .

  In SA3 corresponding to the gradient calculating means 122, the friction coefficient μ of the clutch C1 calculated in SA2 and the gradient Δμ / ΔV that is the change gradient of the differential rotation V of the clutch C1 are calculated. When the flowchart of FIG. 11 is repeatedly executed at predetermined times, the gradient is calculated by the friction coefficient μ of the clutch C1 calculated at SA2 at the previous execution and SA2 at the current execution. The amount of change in the difference between the friction coefficient μ of the clutch C1 between the differential rotation V of the clutch C1 detected in SA1 at the previous execution and the differential rotation V of the clutch C1 detected in SA1 at the current execution It can also be calculated as the ratio of

  In SA4, it is determined whether or not the value of the gradient Δμ / ΔV calculated in SA3 is equal to or less than a predetermined value Gth set in advance. Here, the magnitude of the predetermined value Gth is a value obtained experimentally in advance so that sufficient damping performance of the shudder can be secured in the clutch C1. This is a value that allows the shudder to be sufficiently attenuated even if it does not occur or even occurs. When the value of the gradient Δμ / ΔV is equal to or smaller than the predetermined value Gth, it is determined that there is a possibility that a shudder may occur, the determination of this step is affirmed, and SA5 and subsequent steps are executed. On the other hand, if the value of the gradient Δμ / ΔV is larger than the predetermined value Gth, the judgment of this step is denied and the present flowchart is ended because it is assumed that the shudder does not occur or is sufficiently attenuated even if it occurs. .

In SA5 corresponding to the hydraulic control means 124, the engagement hydraulic pressure PC1 of the clutch _C1 is controlled so that the gradient Δμ / ΔV is larger than the predetermined value Gth. Specifically, for example, with respect to a predetermined pattern as an engagement pressure P _C1 of the clutch C1 for the lapse of time from the start time of the release control from the neutral control, the gradient [Delta] [mu / [Delta] V is greater than the predetermined value Gth The correction value ΔP _C1 necessary for this is calculated, and the engagement hydraulic pressure P _C1 is corrected by the correction value ΔP _C1 .

In SA6 corresponding to the input torque control means 126, the input torque to the clutch C1 is controlled so that the gradient Δμ / ΔV is larger than the predetermined value Gth. The control of the input torque of the clutch C1 is performed by controlling the output torque of the engine 30. Specifically, for example, the output of the engine 30 is increased or decreased from the pattern with respect to a predetermined pattern as the engine output with respect to the passage of time from the start time of the release control from the neutral control. Input torque is increased or decreased. The input torque of the clutch C1 is controlled in order to control the differential rotation V of the clutch C1. For example, the correction value V _rev of the differential rotation V is calculated so that the gradient Δμ / ΔV becomes the change amount ΔV of the differential rotation necessary for the gradient Δμ / ΔV to be larger than the predetermined value Gth, and the differential rotation is performed by the correction value V _rev. This is done by correcting V.

In SA7 corresponding to the learning control unit 130, based on the contents of control of the output torque of the engine 30 performed controlled, and in SA6 engagement pressure P _C1 of the clutch C1 that has been performed in SA5, the learning control is performed It is. Specifically, the learning control is performed by, for example, offsetting the predetermined pattern as the time change of the engagement oil pressure P _C1 over time by the correction value ΔP _C1 of the engagement oil pressure P _C1 performed in SA5. Do. Similarly, the pattern predetermined as the time change of the engine output with the passage of time is also changed based on the correction value of the engine output performed in SA6.

According to the above-described embodiment, the control of the engaging pressure P _C1 of the clutch C1 is a starting clutch by the hydraulic pressure control unit 124, and the control of the input torque of the clutch C1 by the input torque control means 126, at least one of As a result, the value Δμ / ΔV of the change gradient with respect to the differential rotation V of the friction coefficient μ of the clutch C1 is set to be equal to or greater than the predetermined value Gth. The shudder generated based on / ΔV can be reduced.

Further, according to the above-described embodiment, when the change gradient Δμ / ΔV with respect to the differential rotation V of the friction coefficient μ is equal to or less than the predetermined value Gth, the control of the engagement hydraulic pressure P _C1 of the clutch C1 by the hydraulic control means 124 and Since the input torque control by the input torque control means 126 is executed, the shudder generated based on the value of the change gradient Δμ / ΔV with respect to the differential rotation V of the friction coefficient μ can be reduced.

Furthermore, according to the embodiments described above, the control of the input torque by controlling and the input torque control means 126 of the engaging pressure P _C1 of the clutch C1 by the hydraulic control unit 124 is executed in the return control from the neutral control Therefore, in a vehicle state where the vehicle speed is very low and the driver feels uncomfortable, the shudder generated based on the value of the change gradient Δμ / ΔV with respect to the differential rotation V of the friction coefficient μ can be reduced.

  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 automatic transmission 10 is a stepped transmission having six forward speeds and one reverse speed, but is not limited thereto. For example, when the automatic transmission 10 is a stepped transmission, the number of shift stages is not limited. Further, the automatic transmission is not limited to the internal transmission disclosed in the embodiment, and may be a so-called double clutch type automatic transmission. Further, instead of the automatic transmission 10, there is provided a power transmission device having a manual transmission and a clutch for switching between transmission and interruption of power between the manual transmission and the engine 30, and switching in the clutch, or Switching in the clutch and shifting in the manual transmission are judged by a computer or the like and automatically executed by an actuator, for example, an automatic manual transmission (AMT) or a multimode manual transmission (MMT). The present invention can also be applied to a power transmission device called “Transmission”.

  In the above-described embodiment, the clutch C1 provided inside the automatic transmission 10 is used as the starting clutch. However, the present invention is not limited to such a mode. A starting clutch provided separately from the automatic transmission 10 can also be controlled by the present invention. Further, the automatic transmission 10 may be a continuously variable transmission (CVT) as long as it has an engagement device that can shut off power when neutral control is executed, such as a starting clutch. That is, the present invention can be applied as long as neutral control can be performed and a predetermined engagement device is engaged when neutral control is canceled.

  In the above-described embodiment, the starting clutch C is the clutch C1 of the automatic transmission 10. However, the torque converter 32 has a lock-up clutch that can connect the turbine shaft and the pump shaft. In this case, the control device of the present invention can be applied to the engagement of the lockup clutch.

  In the above-described embodiment, the clutch C1 is used as the starting clutch. However, the clutch C1 is not necessarily limited to the clutch, and may be a brake B as long as it is a hydraulic friction engagement device. It changes suitably according to a structure.

  In the above-described embodiment, the present invention is applied in the return control from the neutral control of the automatic transmission 10, but is not limited to this. That is, the present invention can be widely applied in the control of the hydraulic friction engagement device from the released state to the engaged state. For example, in the return control for returning from an idle stop in which the engine is stopped while the vehicle is stopped, the present invention can also be applied to the case where the engine 30 is started and the clutch C1 is engaged. It is possible to reduce the shudder associated with the combination. That is, the neutral control return means 110 in the above-described embodiment can operate as the engagement control means of the hydraulic engagement device. Furthermore, although the hydraulic friction engagement device is used as the starting clutch, a dry clutch can be used instead.

In the above-described embodiment, the differential rotational speed V of the clutch C1 is calculated based on the output shaft rotational speed NOUT and the turbine rotational speed _NT . However, the present invention is not limited to this, and for example, the vehicle speed may be used. .

  In the above-described embodiment, the input torque control means 126 controls the output torque of the engine 30 in order to change the input torque to the clutch C1, but the present invention is not limited to this. For example, when an electric motor capable of applying torque is provided on the input shaft of the clutch C1, the output torque of the electric motor may be controlled instead of or in addition to the control of the engine 30. Good.

In the above-described embodiment, the control of the engagement hydraulic pressure P _C1 by the hydraulic control means 124 and the control of the engine input torque by the input torque control means 126 are performed when the gradient Δμ / ΔV falls below a predetermined value Gth. The predetermined value Gth is set to a value that can sufficiently secure the shudder damping performance in the clutch C1. However, the predetermined value Gth is not limited to this. For example, Gth = 0 can be set in correspondence with Δμ / ΔV = 0 which is the value of the gradient Δμ / ΔV when the shudder is generated in the clutch C1.

In the above-described embodiment, the hydraulic pressure control unit 124 determines that the gradient Δμ / ΔV is less than the predetermined value Gth when the value of the gradient Δμ / ΔV detected by the gradient calculating unit 112 is equal to or less than the predetermined value Gth. The engagement hydraulic pressure PC1 of the clutch _C1 is controlled so as to increase. Further, the input torque control means 126 is configured so that the gradient Δμ / ΔV becomes larger than the predetermined value Gth when the value of the gradient Δμ / ΔV detected by the gradient calculating means 122 becomes equal to or less than the predetermined value Gth. The differential rotation V of the clutch C1 is controlled. However, the present invention is not limited to such an embodiment. For example, the hydraulic pressure control unit 124 has a value of Δμ / ΔV, which is a value at which the gradient Δμ / ΔV detected by the gradient calculation unit 112 is generated by a shudder, is 0 or less. In this case, the engagement hydraulic pressure P _C1 of the clutch C1 may be controlled so that the gradient Δμ / ΔV is larger than the predetermined value Gth. Similarly, the input torque control means 126 allows the clutch so that the slope Δμ / ΔV becomes larger than the predetermined value Gth when the value of the slope Δμ / ΔV detected by the slope calculation means 122 becomes 0 or less. The differential rotation V of C1 may be controlled. That is, the determination value of the gradient Δμ / ΔV for determining whether the hydraulic control unit 124 or the input torque control unit 126 starts the control and the gradient Δμ / ΔV are set to be equal to or smaller than the gradient Δμ / ΔV by the hydraulic control unit 124 or the input torque control unit 126. The value of the predetermined value Gth may be different.

In the above-described embodiment, the friction coefficient calculating unit 120 includes the hydraulic oil temperature T _OIL of the clutch C1 detected by the oil temperature T _OIL detection unit 112 and the engagement hydraulic pressure of the clutch C1 detected by the pressing hydraulic pressure detection unit 114. Although the friction coefficient μ of the clutch C1 is calculated based on P _C1 and the differential rotation V of the clutch C1 detected by the differential rotation detection means 116, the present invention is not limited to this mode. For example, the working oil temperature T _OIL of the clutch _C1, when the detection of the engagement oil pressure P _C1, the detection of differential rotation V, and, by the calculation of the friction coefficient μ is repeated by predetermined intervals, the friction coefficient is repeatedly calculated The coefficient of friction μ may be predicted based on μ. In such a case, since the predicted friction coefficient μ can also be calculated by the gradient Δμ / ΔV calculated by the gradient calculation means 122, the hydraulic pressure control means is predicted by predicting that the clutch C1 can generate a shudder. The engagement hydraulic pressure P _C1 can be controlled by 124, and the output torque of the engine 30 can be controlled by the input torque control means 126. Therefore, the generation of the shudder of the clutch C1 can be prevented in advance.

In the above embodiment, as shown in the flowchart of FIG. 11, the clutch C1 engagement hydraulic pressure _PC1 is controlled by the hydraulic control means 124 (SA5), and then the output torque of the engine 30 by the input torque control means 126 is controlled. That is, the input torque of the clutch C1 is controlled (SA6), but the present invention is not limited to this mode. For example, either the control of the output torque of the engine 30 by controlling the input torque control means 126 of the clutch C1 engaging pressure P _C1 by the hydraulic pressure control unit 124 is performed, at which only one is not able to suppress the occurrence of shudder That is, when the gradient Δμ / ΔV <Gth still remains, the other may be executed. In this way, shudder can be reduced by simple control. Alternatively, the control of the clutch C1 engaging pressure P _C1 by the hydraulic pressure control unit 124, a control of the output torque of the engine 30 by the input torque control means 126 may be performed simultaneously. In this way, the clutch C1 can escape earlier from a state where the shudder can occur. Further, the resulting control of the clutch C1 engaging pressure P _C1 by the hydraulic pressure control unit 124, a certain effect even if any such only one is performed with control of the output torque of the engine 30 by the input torque control means 126 Can do.

  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.

DESCRIPTION OF SYMBOLS 10: Automatic transmission 30: Engine 46: Drive wheel 52: Accelerator pedal 108: Neutral control means 106: Neutral control condition determination means 110: Neutral control return means 112: Oil temperature detection means 114: Pressing pressure detection means 116: Differential rotation Detection means 118: Storage means 120: Friction coefficient calculation means 122: Gradient calculation means 124: Hydraulic control means 126: Input torque control means 130: Learning control means

Claims (3)

A control device for an automatic transmission having a hydraulic friction engagement device,
When the hydraulic friction engagement device is engaged, the friction coefficient of the hydraulic friction engagement device is calculated based on the differential rotation, pressing pressure, and temperature of the hydraulic friction engagement device,
Controlling at least one of an engagement hydraulic pressure and an input torque of the hydraulic friction engagement device such that a change gradient of the calculated friction coefficient with respect to the differential rotation is a predetermined value or more;
A control device for an automatic transmission characterized by the above. The control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed when a change gradient of the friction coefficient with respect to the differential rotation is a predetermined value or less,
The control device for an automatic transmission according to claim 2. The control of the engagement hydraulic pressure and the input torque of the hydraulic friction engagement device is executed in the return control from the neutral control,
The control device for an automatic transmission according to claim 1, wherein

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