JP2011144878A - Hydraulic control device for vehicular power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an engagement shock caused by crushing a cushion plate when releasing neutral control. <P>SOLUTION: When releasing neutral control, the rise of clutch pressure Pc is temporarily put on standby at an imminent standby pressure F<SB>WDB</SB>immediately before a cushion crushing oil pressure P<SB>CPF</SB>equivalent to a cushion load F<SB>CP</SB>for crushing the cushion plate 68 is applied to the cushion plate 68. The sudden rise of oil pressure applied to a friction engaging element 52 when crushing the cushion plate 68 thereby starts from the vicinity of the imminent standby pressure P<SB>WDB</SB>. In comparison with the case where the clutch pressure Pc rises as it is to crush the cushion plate 68 without being temporarily put on standby at the imminent standby pressure P<SB>WDB</SB>immediately before the cushion crushing oil pressure P<SB>CPF</SB>is applied to the cushion plate 68, for instance, the sudden rise of the oil pressure applied to the friction engaging element 52 is reduced to suppress the engagement shock. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydraulic control device for a vehicle power transmission device that executes neutral control (N control), and more particularly to control when canceling neutral control.

  For example, when a predetermined neutral control condition such as when the foot brake is on and the vehicle is stopped at the traveling position is satisfied, the engagement device provided in the power transmission path from the engine to the drive wheels is slipped. A hydraulic control device for a vehicle power transmission device that performs neutral control for suppressing an idling load of an engine by setting the power transmission path to a power transmission suppression state as a release state is well known. In such neutral control, for example, transmission of the engine output to the drive wheel side is substantially cut off by slipping or releasing the engagement device while the shift position is in the “D” position. When the neutral control is released, that is, when returning from the neutral control, the engaging device is engaged.

  Here, for example, as shown in Patent Documents 1 and 2, when a cushion plate is interposed between a friction engagement element (friction plate) constituting the hydraulic friction engagement device and a pressing portion of the piston There is. Such a cushion plate does not control (or cannot control) the hydraulic pressure at the time of releasing the hydraulic friction engagement device, for example. In the case where a structure for releasing is adopted, it is provided for the purpose of reducing the shock at the time of releasing.

JP 2004-212182 A JP 2004-286182 A

  By the way, when the hydraulic friction engagement device is engaged, a low-pressure standby state (or a sweep-up state) is set after first fill (rapid filling), and then the hydraulic pressure is rapidly increased toward the final engagement pressure. It has been proposed. On the other hand, when a hydraulic friction engagement device having a cushion plate is engaged, the actual engagement pressure (actual engagement pressure) when the piston presses the friction plate is in the process of crushing the cushion plate. The hydraulic pressure for crushing the cushion plate is divided into the hydraulic pressure for pressing the friction plate (that is, the hydraulic pressure for increasing the torque transmission capacity). Then, in the process of increasing the engagement pressure, until the cushion plate is completely crushed, the controllability of the hydraulic pressure that presses the friction plate due to the shape change of the cushion plate (followability to the command hydraulic pressure) may be reduced. There is sex. That is, until the cushion plate is completely crushed, even if the command hydraulic pressure is increased and the actual engagement pressure is increased, the hydraulic pressure for pressing the friction plate is not increased by the hydraulic pressure for crushing the cushion plate, There is a possibility that the difference between the hydraulic pressure that presses the friction plate and the command hydraulic pressure (actual hydraulic pressure) increases. Therefore, if the cushion plate is completely crushed at a certain point in the process of increasing the engagement pressure, the actual engagement pressure becomes the hydraulic pressure that presses the friction plate as it is. Is rapidly increased to the actual engagement pressure. When such a phenomenon occurs, for example, in the process of rapidly increasing the command hydraulic pressure toward the final engagement pressure, the hydraulic pressure that presses the friction plate is suddenly increased and the hydraulic friction engagement device is rapidly engaged. There is a possibility that the engagement shock is increased by a sudden inertia change at that time. Such a problem is not yet known.

  The present invention has been made in the background of the above circumstances, the purpose of which is to increase the engagement pressure in order to engage the hydraulic friction engagement device in releasing the neutral control, An object of the present invention is to provide a hydraulic control device for a vehicle power transmission device that can suppress an engagement shock caused by a cushion plate being crushed.

  To achieve the above object, the gist of the present invention is that (a) the power of the engine is transmitted to the drive wheel side by engagement and a spring material is provided between the friction engagement element and the pressing portion of the piston. A hydraulic friction engagement device with a cushion plate interposed between the engine and the drive wheel when the neutral friction control device is in a slipping state or a release state when a predetermined neutral control condition is satisfied at the running position; A hydraulic control device for a vehicle power transmission device that executes neutral control for suppressing idling load of the engine by setting the power transmission path between the two to a power transmission suppression state, and (b) When increasing the engagement pressure to engage the hydraulic friction engagement device at the time of release, the cushion load for crushing the cushion plate Corresponding hydraulic pressure is to be temporarily waiting the rise of the engaging pressure at standby pressure immediately before acting on the cushion plate.

  In this way, when the engagement pressure is increased to engage the hydraulic friction engagement device when the neutral control is released, the hydraulic pressure corresponding to the cushion load for crushing the cushion plate is reduced. Since the increase in the engagement pressure is temporarily held at the standby pressure immediately before acting on the cushion plate, the sudden increase in the hydraulic pressure that presses the friction engagement element when the cushion plate is crushed is the above standby pressure. When the pressure rises from the vicinity, for example, when the hydraulic pressure corresponding to the cushion load is just before the pressure acting on the cushion plate, the increase in the engagement pressure is raised temporarily without being temporarily waited and the cushion plate is crushed In comparison with this, the sudden increase of the hydraulic pressure that presses the friction engagement element is reduced, and the engagement shock is suppressed. As described above, when the engagement pressure is increased in order to engage the hydraulic friction engagement device when the neutral control is released, it is possible to suppress the engagement shock caused by the collapse of the cushion plate.

  Here, preferably, during the temporary standby at the immediately preceding standby pressure, the rotational speed of the input side of the hydraulic friction engagement device associated with the hydraulic pressure corresponding to the cushion load acting on the cushion plate Based on this change, the next standby pressure when temporarily waiting for the increase in the engagement pressure is set by learning control. In this way, it is possible to set an optimum standby pressure for suppressing the engagement shock for each vehicle without being influenced by individual differences in the cushion load. That is, in order to suppress the engagement shock caused by the collapse of the cushion plate as much as possible, for example, it is desirable to set the standby pressure to a hydraulic pressure just before the hydraulic pressure corresponding to the cushion load acts on the cushion plate. If the standby pressure is set to the very limit without taking a margin for the hydraulic pressure corresponding to the load (there is no margin), there will be individual differences in the cushion load, etc., so the lower limit product will wait at the set standby pressure. If the hydraulic pressure corresponding to the cushion load is exceeded, a corresponding engagement shock may occur. Therefore, by detecting the amount of change in the rotational speed of the input side of the hydraulic friction engagement device that causes a change corresponding to the occurrence of such an engagement shock, the next standby pressure is appropriately corrected by learning control, and the vehicle Set the optimum standby pressure for each.

  Preferably, the learning control of the standby pressure is performed each time the amount of change in the input-side rotational speed during a temporary standby at the immediately preceding standby pressure drops more than a predetermined value. Is to gradually reduce the standby pressure from the current standby pressure. In this way, the optimum standby pressure for suppressing the engagement shock can be set more reliably for each vehicle without being influenced by individual differences in the cushion load.

  Preferably, the hydraulic friction engagement device is connected to the engine via a fluid transmission device, and when the neutral control with accelerator on is released, the engine rotational speed is increased. The engagement pressure is kept low so that the output rotation speed of the fluid transmission device is blown up, and after the output rotation speed of the fluid transmission device is blown up, toward the engagement of the hydraulic friction engagement device. The engagement pressure is increased again, and then the engagement pressure is changed by feedback control so that the differential rotational speed between the input and output of the hydraulic friction engagement device is zero with a predetermined change in rotation. When the engagement pressure is increased again after the low-pressure standby, the increase in the engagement pressure is temporarily caused by the standby pressure immediately before the hydraulic pressure corresponding to the cushion load acts on the cushion plate. There to be machine. In this way, when the neutral control with accelerator on is released, the engagement pressure is first waited for low pressure, and then the engagement pressure is increased again toward the engagement of the hydraulic friction engagement device, Further, by subsequently changing the engagement pressure by feedback control based on the differential rotational speed of the hydraulic friction engagement device, it is possible to suppress a drop in torque after engagement. In other words, when the neutral control with accelerator on is released, the engagement pressure is increased so that the hydraulic friction engagement device is engaged before the engine torque rises without blowing up the output rotational speed of the fluid transmission, for example. Then, before complete engagement, a driving force is generated by the torque transfer capacity of the hydraulic friction engagement device and the inertia torque due to the decrease in the output rotational speed of the fluid transmission device. The engine torque becomes the driving force, but if the driving force before the engagement is large, the driving force (acceleration) may drop once after the engagement. Therefore, the output rotational speed of the fluid transmission device is once blown up, and then the output rotational speed of the fluid transmission device and the output rotational speed of the hydraulic friction engagement device are slowly brought close to each other with a predetermined rotational change. Suppresses the drop in torque after merging. However, in the hydraulic friction engagement device having the cushion plate, the hydraulic pressure corresponding to the cushion load is increased in the process of increasing the engagement pressure again toward the engagement of the hydraulic friction engagement device after the low pressure standby. Acting on can increase the engagement shock. In contrast, when the engagement pressure is increased again after the low-pressure standby, the standby pressure immediately before the hydraulic pressure corresponding to the cushion load acts on the cushion plate is temporarily standby for the increase in the engagement pressure. Therefore, the sudden increase of the hydraulic pressure that presses the friction engagement element is reduced, and the engagement shock is appropriately suppressed.

  Preferably, an automatic transmission is provided in the power transmission path from the engine to the drive wheels. In this automatic transmission, a plurality of gear stages (shift stages) are selectively achieved by selectively connecting the rotating elements of a plurality of planetary gear units by an engagement device, for example, forward four stages, forward Various planetary gear type automatic transmissions having 5 speeds, 6 forward speeds, and more, and a transmission belt functioning as a power transmission member are wound around a pair of variable pulleys having variable effective diameters. A so-called belt-type continuously variable transmission in which the gear ratio is continuously changed steplessly, a pair of cones rotated around a common shaft center, and a plurality of rollers that can rotate around the shaft center and rotate around the shaft center. For a so-called traction type continuously variable transmission in which the transmission gear ratio is variable by changing the crossing angle between the rotation center of the roller and the shaft center between the pair of cones, or the engine shaft or output shaft Power transmission possible It constituted by an automatic transmission which motor is mounted on a hybrid vehicle of a so-called parallel type provided in. Further, the mounting posture of the 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 axis of the automatic transmission is in the width direction of the vehicle. It may be a vertical installation type such as an FR (front engine / rear drive) vehicle in the longitudinal direction.

  Preferably, for example, the neutral control of a vehicle including a planetary gear type automatic transmission is used to release all the engaging devices or to form a gear stage of the transmission in the “R” or “D” position. This is executed by releasing one of the engaging devices to form a neutral state of the automatic transmission in which the power transmission path in the automatic transmission is interrupted. Further, for example, neutral control of a vehicle equipped with a belt type continuously variable transmission or a traction type continuously variable transmission includes well-known engagement devices and gear devices provided in a power transmission path from the engine to driving wheels. This is executed by forming the neutral state of the power transmission path by setting the engaging device in the forward / reverse switching device to the slip state or the release state. Further, for example, the engagement device provided in the power transmission path is set to the slip state or the release state separately from the engagement device included in the planetary gear type automatic transmission and the engagement device included in the forward / reverse switching device. Neutral control is also performed by forming a state.

  Preferably, as the engagement device, a friction engagement device such as a multi-plate or single-plate clutch or brake that is engaged by a hydraulic actuator is widely used. The oil pump for supplying the hydraulic oil for engaging the hydraulic friction engagement device may be driven by a driving power source for traveling to discharge the hydraulic oil, but is disposed separately from the driving power source, for example. It may be driven by a dedicated electric motor provided. The hydraulic control circuit including this hydraulic friction engagement device responds by supplying the output hydraulic pressure of a linear solenoid valve as an electromagnetic valve device directly to the hydraulic actuator (hydraulic cylinder) of the hydraulic friction engagement device, for example. Although it is desirable from the standpoint of performance, the shift control valve (shift control valve) is controlled by using the output hydraulic pressure of the linear solenoid valve as the pilot hydraulic pressure, and the hydraulic oil is supplied from the control valve to the hydraulic actuator. You can also. The linear solenoid valve is provided, for example, corresponding to each of a plurality of hydraulic friction engagement devices, but a plurality of hydraulic solenoid valves that are not simultaneously engaged, engaged, or controlled to be released. When a friction engagement device exists, various modes are possible, such as providing a common linear solenoid valve for them. In addition, it is not always necessary to perform the hydraulic control of all the hydraulic friction engagement devices with the linear solenoid valve. Some or all of the hydraulic control may be pressure control means other than the linear solenoid valve, such as duty control of the ON-OFF solenoid valve. You can go there.

  Preferably, an internal combustion engine such as a gasoline engine or a diesel engine is widely used as the engine. Further, an electric motor or the like may be used in addition to the engine as a driving power source for auxiliary traveling.

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

1 is a skeleton diagram illustrating a configuration of an automatic transmission provided in a vehicle to which the present invention is applied. FIG. 2 is an operation chart for explaining a combination of operations of friction engagement devices when a plurality of gear stages of the automatic transmission of FIG. 1 are established. It is principal part sectional drawing which shows a part of automatic transmission containing the clutch C1. It is a block diagram explaining the principal part of the electrical control system provided in the vehicle in order to control the automatic transmission etc. of FIG. FIG. 5 is a circuit diagram relating to a linear solenoid valve that controls the operation of each hydraulic actuator for clutches and brakes in the hydraulic control circuit of FIG. 4. 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 which shows an example of the relationship (engine torque map) calculated | required experimentally beforehand and memorize | stored by using the throttle valve opening as a parameter. It is a figure which shows an example of the shift map used for determination of the gear stage of the automatic transmission of FIG. It is an example of a clutch hydraulic pressure command value when neutral control is released, and is a predetermined engagement pattern when accelerator-off is normally released. It is a figure which shows an example at the time of using the engagement pattern before a change in a present Example (before application of this invention) as a predetermined engagement pattern at the time of neutral control cancellation | release with an accelerator on. 6 is a flowchart for explaining a control operation for suppressing an engagement shock caused by a cushion plate being crushed when canceling neutral control, that is, a main part of a control operation of the electronic control device of FIG. 4. FIG. 12 is a time chart corresponding to the control operation of FIG. 11 when the engagement pattern after the change in the present embodiment (after application of the present invention) is used as the predetermined engagement pattern at the time of neutral control release with accelerator on. It is a figure which shows an example. FIG. 7 is a functional block diagram illustrating a main part of a control function of the electronic control device of FIG. 4, and is another embodiment corresponding to the functional block diagram of FIG. 6. 6 is a flowchart for explaining a control operation for learning control of a main part of the control operation of the electronic control device of FIG. It is a time chart corresponding to the control action of FIG.

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

  FIG. 1 is a skeleton diagram illustrating a configuration of an automatic transmission 12 provided in a vehicle 10 to which the present invention is applied. FIG. 2 is an operation table for explaining an operation state of the friction engagement device when a plurality of gear stages GS (shift stages GS) of the automatic transmission 12 is established. This automatic transmission 12 is suitably used for an FF vehicle mounted in the left-right direction (horizontal) of the vehicle 10, and is a transaxle case 14 (hereinafter, case 14) as a non-rotating member attached to the vehicle body. Inside, a first transmission unit 18 mainly composed of a single pinion type first planetary gear device 16, a double pinion type second planetary gear device 20, and a single pinion type third planetary gear device 22 are mainly used. As a Ravigneaux-type second transmission unit 24 on a common axis C, and the input shaft 26 is rotated and output from the output gear 28. The input shaft 26 corresponds to an input rotating member of the automatic transmission 12, and in this embodiment, a turbine of a torque converter 32 as a fluid transmission device that is rotationally driven by an engine 30 that is a driving force source for traveling. It is constructed integrally with the shaft. Further, the output gear 28 corresponds to an output rotating member of the automatic transmission 12, and in this embodiment, for example, meshes with the diff ring gear 36 in order to transmit power to the differential gear device 34 shown in FIG. The counter drive gears constituting the counter gear pair are engaged with the counter driven gear arranged coaxially with the differential drive pinion constituting the final gear pair. In the automatic transmission 12 and the like configured as described above, the output of the engine 30 is output from the vehicle power transmission device 11 including the torque converter 32, the automatic transmission 12, the differential gear device 34, the pair of axles 38, and the like. Are sequentially transmitted to the left and right drive wheels 40 (see FIG. 4). The automatic transmission 12 and the torque converter 32 are substantially symmetrical with respect to the center line (axial center) C, and the lower half of the axial center C is omitted in the skeleton diagram of FIG.

  The torque converter 32 includes a lockup clutch 42 as a lockup mechanism that directly transmits the power of the engine 30 to the input shaft 26 without passing through fluid. The lock-up clutch 42 is a hydraulic friction clutch that is frictionally engaged by a differential pressure ΔP between the hydraulic pressure in the engagement-side oil chamber 44 and the hydraulic pressure in the release-side oil chamber 46, and is completely engaged (locked). The power of the engine 30 is directly transmitted to the input shaft 26. Further, for example, 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 26) is driven at a predetermined slip amount of, for example, about 50 rpm when the vehicle is driven (power-on). ) With respect to the output rotation member of the engine 30, while the vehicle is not driven (power off), the output rotation member of the engine 30 is rotated with respect to the turbine shaft with a predetermined slip amount of, for example, about −50 rpm. It is done.

  The automatic transmission 12 corresponds to the combination of any one of the rotation states (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) of the first transmission unit 18 and the second transmission unit 24. Six forward gear stages (forward shift stages) from the first gear stage “1st” to the sixth gear stage “6th” are established, and the reverse gear stage (reverse shift stage) of the reverse gear 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 clutch C1, C2 and the brakes B1 to B3 are all released to be in the neutral state. In the case 14, a mechanical oil pump 48 that generates a working hydraulic pressure that is a source pressure for operating the clutches C1 and C2 and the brakes B1 to B3 by being rotationally driven by the engine 30 is provided. Is provided.

The operation table of FIG. 2 summarizes the relationship between the gear stages GS and the operation states of the clutches C1 and C2 and the brakes B1 to B3, where “◯” indicates engagement and “◎” indicates engine braking. Only represents engagement. Since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first gear stage “1st”, it is not always necessary to engage the brake B2 at the time of start (acceleration). That is, it is sufficient to engage only the clutch C1 at the start, and for example, the clutch C1 is engaged when returning from the neutral control described later. Thus, the clutch C1 functions as a starting clutch. The gear ratio γGS (= the rotational speed N _IN of the input shaft 26 / the rotational speed N _OUT of the output gear 28) of each gear stage GS is determined by the first planetary gear device 16, the second planetary gear device 20, and the third planetary gear device. Each gear ratio of the gear unit 22 (= the number of teeth of the sun gear / the number of teeth of the ring gear) is appropriately determined by ρ1, ρ2, and ρ3.

  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 controlled by a hydraulic actuator such as a multi-plate clutch or a brake. This is a hydraulic friction engagement device that transmits the motive power to the drive wheel 40 side. The clutch C and brake B are engaged and disengaged by excitation, de-excitation, and current control of the linear solenoid valves SL1 to SL5 (see FIGS. 4 and 5) in the hydraulic control circuit 100. The transient engagement hydraulic pressure at the time of release is controlled.

  FIG. 3 is a cross-sectional view of an essential part showing a part of the automatic transmission 12 including the clutch C1. Here, the hydraulic friction engagement device will be described by exemplifying the clutch C1, but the clutch C2 basically has the same configuration. Similarly to FIG. 1, the lower half of the axis C is omitted in the cross-sectional view of FIG. 2.

  As shown in FIG. 3, the input shaft 26 is supported by the case 14 so as to be relatively rotatable via a bearing, and is provided with a flange portion 26 a that extends perpendicularly to the axis C. An annular base member 50 is provided on the outer peripheral edge of the flange portion 26 a of the input shaft 26 and is integrally welded to the outer peripheral edge and supported so as to be relatively rotatable with respect to the case 14. A clutch drum 54 that supports a friction engagement element 52 that is a constituent member of the clutch C <b> 1 is integrally welded to the outer peripheral surface of the base member 50, and is rotated integrally with the input shaft 26.

  The clutch drum 54 is a bottomed cylindrical member that opens in one axial direction, and has a substantially annular plate-like (disc-like) bottom plate portion whose inner peripheral surface is welded to the outer peripheral surface of the base member 50. 54a and a cylindrical tube portion 54b connected to the outer peripheral surface of the bottom plate portion 54a and extending in parallel with the axis. Spline teeth extending in the longitudinal direction are provided on the inner peripheral surface of the cylinder portion 54b of the clutch drum 54, and a plurality of outer peripheral edges of the separate plate 52a of the friction engagement element 52 constituting the clutch C1 are spline-fitted. Yes.

  The friction engagement element 52 includes a plurality of substantially annular plate-shaped (disc-shaped) separate plates 52a whose outer peripheral edges are spline-fitted to the inner peripheral surface of the cylindrical portion 54b, and the plurality of separate plates 52a. And a plurality of substantially annular plate-like (disc-like) friction plates 52b whose inner peripheral edge is spline-fitted to the outer peripheral surface of the clutch hub 56. The clutch hub 56 is connected to the sun gear S3 of the third planetary gear unit 22 and transmits its rotation.

  Between the clutch drum 54 and the clutch hub 56, a piston 58 and a spring receiving plate 60 for pressing the friction engagement element 52 from the clutch drum 54 side are disposed. The piston 58 is fitted with an inner peripheral surface of the piston 58 so as to be slidable in the axial direction with respect to the input shaft 26 via a seal, and a pressing portion 58a extending in the direction of the friction engagement element 52 is provided on the outer peripheral edge. ing. The spring receiving plate 60 is prevented from moving in the axial direction by abutting against a snap ring 62 fitted to the input shaft 26, and is interposed between the piston 58 and the spring receiving plate 60. The spring 58 is prevented from moving in the other axial direction by a return spring 64 that urges the piston 58 to abut against the bottom plate portion 54a of the clutch drum 54.

  Further, in the clutch C1, a snap ring 66 for preventing the friction plates 52a and 52b from moving in the axial direction of the friction plates is fitted on the inner peripheral surface of the cylindrical portion 54b. Further, between the separation plate 52a on the opposite side of the snap ring 66 of the friction engagement element 52 and the pressing portion 58a of the piston 58, the outer peripheral edge is spline-fitted to the spline teeth of the cylindrical portion 54b and has a diameter. A cushion plate 68, which is a ring-shaped spring material, is provided on the inner side in the direction so as to extend to a length substantially equal to that of the separate plate 52a. Since the cushion plate 68 is configured to release the clutch C1 by simply draining (discharging) the hydraulic oil, the hydraulic pressure when the clutch C1 is released cannot be controlled as will be described later, for example. It is provided for the purpose of reducing time shock.

  In the clutch C1 configured as described above, when the hydraulic oil is supplied into the oil chamber 72 from the hydraulic oil passage 70 provided in the input shaft 26, the piston 58 is attached to the return spring 64 by the hydraulic pressure of the hydraulic oil. It is moved in the direction of the friction engagement element 52 against the force, and the pressing portion 58 a presses the inner peripheral edge of the cushion plate 68. By this pressing, a moment is generated with the outer peripheral edge of the cushion plate 68 as a fulcrum, and the separate plate 52a adjacent to the cushion plate 68 is pressed toward the snap ring 66 by this moment force. Thereby, the separate plate 52a and the friction plate 52b are pressed against the snap ring 66 side. Since the snap ring 66 prevents the separation plate 52a and the friction plate 52b from moving in the axial direction, the friction engagement element 52 is engaged, that is, the clutch C1 is engaged. The oil chamber 72 and the piston 58 function as a hydraulic actuator for the clutch C1 that is operated by the action of hydraulic oil.

  FIG. 4 is a block diagram illustrating a main part of an electrical control system provided in the vehicle 10 for controlling the engine 30, the automatic transmission 12, and the like. In FIG. 4, the vehicle 10 is provided with an electronic control device 120 including a hydraulic control device related to, for example, neutral control of the automatic transmission 12. The electronic control device 120 includes a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, for example. The CPU uses a temporary storage function of the RAM and stores a program stored in the ROM in advance. In accordance with the signal processing, the output control of the engine 30 and the shift control of the automatic transmission 12 are executed, and the engine control device for engine control and the linear in the hydraulic control circuit 100 are executed as necessary. It is divided into a hydraulic control device for shift control for controlling the solenoid valves SL1 to SL5.

The electronic control unit 120 detects, for example, a signal representing the hydraulic oil temperature T _OIL that is the temperature of the hydraulic oil (for example, a known ATF) in the hydraulic control circuit 100 detected by the hydraulic oil temperature sensor 74, and is detected by the accelerator opening sensor 76. A signal indicating the accelerator opening degree Acc, which is an operation amount of the accelerator pedal 78 as a required amount (driver required amount) for the vehicle 10 by the driver, and an engine which is the rotational speed of the engine 30 detected by the engine rotational speed sensor 80 signal representative of the rotational speed N _E, a signal representing the cooling water temperature T _W of the engine 30 detected by a coolant temperature sensor 82, a signal representing the intake air quantity Q of the engine 30 detected by an intake air amount sensor 84, a throttle valve opening signal representing the throttle valve opening theta _TH is a degree of the detected electronic throttle valve by degrees sensor 86, vehicle Signal representative of the output speed N _OUT is the rotational speed of the output gear 28 corresponding to the vehicle speed V detected by the sensor 88, in a foot brake operation is a service brake, which is detected by the brake switch 90 (in depressing) A signal indicating the operation (ON) B _ON of the foot brake pedal 92 shown, a signal indicating the lever position (operation position, shift position) P _SH of the shift lever 96 detected by the lever position sensor 94, and detection by the turbine rotational speed sensor 98 A signal representing the turbine rotational speed N _T that is the rotational speed of the turbine of the torque converter 32 (that is, the input rotational speed N _IN that is the rotational speed of the input shaft 26) is supplied.

Further, the electronic control unit 120 outputs an engine output control command signal S _E for controlling the output of the engine 30, for example, a drive signal to the throttle actuator for controlling the opening / closing of the electronic throttle valve according to the accelerator opening Acc, An injection signal for controlling the fuel injection amount injected from the fuel injection device, an ignition timing signal for controlling the ignition timing of the engine 30 by the igniter, and the like are output. Further, a hydraulic control command signal S _P for shift control of the automatic transmission 12, for example, excitation and non-excitation of the linear solenoid valves SL 1 to SL 5 in the hydraulic control circuit 100 for switching the gear stage GS of the automatic transmission 12, etc. A valve command signal (hydraulic command value, drive signal) for controlling the pressure, a drive signal to the linear solenoid valve SLT for controlling the pressure of the line oil pressure PL, and the like are output.

  Further, the shift lever 96 is disposed, for example, in the vicinity of the driver's seat and is manually moved to five lever positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It is designed to be operated.

  The “P” position (range) releases a power transmission path in the automatic transmission 12, that is, a neutral state (neutral state) in which the power transmission in the automatic transmission 12 is interrupted, and is mechanically output by the mechanical parking mechanism. This is a parking position (position) for preventing (locking) the rotation of 28. The “R” position is a reverse travel position (position) for making the rotation direction of the output gear 28 of the automatic transmission 12 reverse. The “N” position is a neutral position (position) for achieving a neutral state in which power transmission in the automatic transmission 12 is interrupted. Further, the “D” position is a shift range (D range) that allows the automatic transmission 12 to change gears, and the automatic shift is performed using all the forward gears from the first gear stage “1st” to the sixth gear stage “6th”. This is the forward travel position (position) for executing the control. The “S” position is a forward travel position (position) in which manual shift can be performed by switching among a plurality of types of shift ranges that limit the change range of the gear steps, that is, a plurality of types of shift ranges with different gear ranges on the high vehicle speed side. is there.

  The “D” position is an automatic transmission mode, which is a control mode in which automatic transmission control is performed in the range from the first gear to the sixth gear as shown in FIG. The “S” position is a lever position to be selected, and the automatic transmission control is executed within a range not exceeding the highest speed gear of each shift range of the automatic transmission 12 and the shift changed by manual operation of the shift lever 96 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).

  In the above embodiment, the shift range on the highest speed side is set (shift range is fixed) by operating the shift lever 96 to the “S” position, but based on the operation of the shift lever 96. The gear position (gear stage) may be designated (gear stage fixed). In this case, every time a manual shift operation is performed in the automatic transmission 12, the shift control is executed so that a desired gear stage corresponding to the operation is obtained.

  FIG. 5 shows a main part of the hydraulic control circuit related to the linear solenoid valves SL1 to SL5 for controlling the operation of the hydraulic actuators (hydraulic cylinders) ACT1 to ACT5 of the clutches C1 and C2 and the brakes B1 to B3 in the hydraulic control circuit 100. FIG.

In FIG. 5, the hydraulic pressure supply device 102 adjusts the first line hydraulic pressure PL <b> 1 using, for example, the hydraulic pressure generated from a mechanical oil pump 48 (see FIG. 1) that is rotationally driven by the engine 30. A valve (first pressure regulating valve) 104, a secondary regulator valve (second pressure regulating valve) 106 that regulates the second line hydraulic pressure PL2 using the hydraulic pressure discharged from the primary regulator valve 104 as a source pressure, and a throttle valve opening θ _TH The signal pressure P _SLT is supplied to the primary regulator valve 104 and the secondary regulator valve 106 in order to regulate the first line oil pressure PL1 and the second line oil pressure PL2 corresponding to the engine load or the like represented by the intake air amount Q or the like. The linear solenoid valve SLT and the first line oil pressure PL1 A modulator valve 108 that regulates the modulator hydraulic pressure PM to a constant value as a source pressure is provided. The hydraulic pressure supply device 102 includes a manual valve 110 that can switch an oil path mechanically or electrically based on an operation of a shift lever 96. For example, when the shift lever 96 is operated to the “D” position or the “S” position, the manual valve 110 outputs the input first line oil pressure PL1 as the drive oil pressure PD, and the shift lever 96 is in the “R” position. When the shift lever 96 is operated to the “P” position or the “N” position, the output of the hydraulic pressure is cut off (drive hydraulic pressure). PD and reverse hydraulic pressure PR are led to the discharge side). In this way, the hydraulic pressure supply device 102 outputs the first line hydraulic pressure PL1, the second line hydraulic pressure PL2, the modulator hydraulic pressure PM, the drive hydraulic pressure PD, and the reverse hydraulic pressure PR.

The hydraulic control circuit 100 is provided with linear solenoid valves SL1 to SL5 (hereinafter referred to as linear solenoid valves SL unless otherwise specified) corresponding to the hydraulic actuators ACT1 to ACT5. In the hydraulic actuators ACT1, ACT2, ACT3, and ACT5, the drive hydraulic pressure PD supplied from the hydraulic supply device 102 by the corresponding linear solenoid valves SL1, SL2, SL3, and SL5 respectively corresponds to the command signal from the electronic control device 120. The engagement hydraulic pressures P _C1 , P _C2 , P _B1 , and P _B3 are adjusted and supplied directly. Further, each hydraulic actuator ACT4 adjusts the first line oil pressure PL1 supplied from the oil pressure supply device 102 to the engagement oil pressure P _B2 according to the command signal from the electronic control device 120 by the corresponding linear solenoid valve SL4. To be supplied directly. Incidentally, either the engagement hydraulic pressure P _B3 or the reverse hydraulic pressure PR adjusted by the linear solenoid valve SL5 is supplied to the hydraulic actuator ACT5 of the brake B3 via the shuttle valve 112.

As described above, the engagement hydraulic pressures P _C1 , P _C2 , P _B1 , and P _B3 supplied to the hydraulic actuators ACT1, ACT2, ACT3, and ACT5 are hydraulic pressures that are adjusted using the drive hydraulic pressure PD as a source pressure. In such a configuration of the hydraulic control circuit 100, for example, when the shift lever 96 is operated from the “D” position to the “N” position during the D → N operation, the drive hydraulic pressure PD as the original pressure cannot be supplied. The engagement hydraulic pressures P _C1 , P _C2 , P _B1 , and P _B3 when C2 and the brakes B1 and B3 are released cannot be adjusted. That is, during the D → N operation, the engagement hydraulic pressures P _C1 , P _C2 , P _B1 , and P _B3 at the time of release are simply discharged. In this embodiment, for example, as shown in FIG. 3, a cushion plate 68 for reducing the shock at the time of release is used as a clutch. C1 is provided. The other clutch C2 and the brakes B1 and B3 may also be provided with a cushion plate similarly to the clutch C1.

The linear solenoid valves SL1 to SL5 basically have the same configuration, and the hydraulic pressures supplied to the hydraulic actuators ACT1 to ACT5 are independently controlled by the electronic control unit 120, independently excited, de-energized, and current controlled. To control the clutch C1, C2 and the engagement hydraulic pressures P _C1 , P _C2 , P _B1 , P _B2 , P _B3 of the brakes B1 to _B3 , respectively. In the automatic transmission 12, for example, each gear stage GS is established by engaging a predetermined engagement device as shown in the engagement operation table of FIG. In the shift control of the automatic transmission 12, a so-called clutch-to-clutch shift is performed by, for example, re-engaging the disengagement side frictional engagement device and the engagement side frictional engagement device of the clutch C and brake B involved in the shift. The At the time of this clutch-to-clutch shift, the release transient engagement hydraulic pressure of the release side frictional engagement device and the engagement side frictional engagement device of the engagement side frictional engagement device are set so that the shift is executed as quickly as possible while suppressing the shift shock. The engagement transient engagement hydraulic pressure is appropriately controlled. 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. 6 is a functional block diagram for explaining a main part of the control function by the electronic control unit 120. In FIG. 6, the engine output control unit, that is, the engine output control means 122 controls the fuel injection amount by the fuel injection device for controlling the fuel injection amount, in addition to controlling the opening and closing of the electronic throttle valve by the throttle actuator, for example, for throttle control. and outputs an engine output control command signal S _E for controlling the ignition device such as an igniter for ignition timing control. For example, the engine output control means 122, the estimated value of the engine rotational speed N _E and engine torque T _E and the throttle valve opening theta _TH as shown in FIG. 7 as a parameter (hereinafter estimated engine torque) in advance experiments with T E _' manner sought controls the opening and closing of the electronic throttle valve so that the throttle valve opening theta _TH which target engine torque T _E ^* obtained based on the actual engine rotational speed N _E from the stored relationship (engine torque map) In addition, the fuel injection amount by the fuel injection device is controlled, and an ignition device such as an igniter is controlled. The target engine torque T _E ^* is obtained by the electronic control unit 120 so as to increase as the accelerator opening Acc increases, for example, based on the accelerator opening Acc corresponding to the driver required amount. Corresponds to torque.

The shift control unit, that is, the shift control means 124, for example, from the relationship (shift map, shift map) stored in advance with the vehicle speed V and the accelerator opening Acc as variables as shown in FIG. 8, for example, the actual vehicle speed V and the accelerator opening Acc. Based on the above, a shift determination is made to determine whether or not the shift of the automatic transmission 12 should be executed. Then, the shift control means 124 determines a gear stage to be shifted in the automatic transmission 12, and outputs a shift command for executing the automatic shift control of the automatic transmission 12 so that the determined gear stage is obtained. For example, the shift control means 124 engages and / or releases the hydraulic friction engagement device involved in the shift of the automatic transmission 12 so that the gear stage is achieved according to the engagement table shown in FIG. command signal and outputs the (shift output command value) _{S P} to the hydraulic control circuit 100.

In the shift map of FIG. 8, 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. The shift line in the shift map in FIG. 8 is, for example, whether or not the actual vehicle speed V crosses the line on the horizontal line indicating the actual accelerator opening Acc (%), that is, the value (shift point) at which the shift on the shift line is to be executed. This is for determining whether or not the vehicle speed (V _S ) has been exceeded, and is also stored in advance as a series of this value V _S, that is, the shift point vehicle speed.

The hydraulic control command signal _SP is a torque command value for controlling the torque transmission capacity (clutch torque) of the clutch C and the brake B, that is, a hydraulic pressure command for generating an engagement hydraulic pressure that provides a necessary torque transmission capacity. For example, a hydraulic pressure command value for discharging the hydraulic oil is output so that a necessary torque transmission capacity for releasing the release side frictional engagement device is obtained as a torque command value of the release side frictional engagement device. In addition, a hydraulic pressure command value to which hydraulic oil is supplied is output so as to obtain a torque transmission capacity necessary for engaging the engagement side frictional engagement device as a torque command value of the engagement side frictional engagement device. The Further, at the time of non-shifting in which any gear stage GS of the automatic transmission 12 is maintained, an engagement hydraulic pressure that can maintain a frictional force that can withstand the transmission input torque _TIN (that is, a torque transmission capacity can be secured) is generated. The hydraulic pressure command value is output.

The hydraulic control circuit 100 in accordance with the oil pressure control command signal S _P by the shift control means 124, as such shifting of the automatic transmission 12 is executed, or the current gear position GS of the automatic transmission 12 is maintained, The linear solenoid valves SL1 to SL5 in the hydraulic control circuit 100 are operated to operate the hydraulic actuators ACT1 to ACT5 of the hydraulic friction engagement device involved in the establishment (formation) of the gear stage GS.

  Here, in the vehicle 10 of the present embodiment, for example, neutral control is executed in order to reduce the idling load of the engine 30 while the vehicle is stopped. In this neutral control, for example, when a predetermined neutral control condition set in advance is satisfied, the power transmission path in the automatic transmission 12 is suppressed by setting the clutch C1, which is a starting clutch, to a predetermined slip state or released state. This is control for setting the state (that is, the state substantially equivalent to the power transmission cutoff state or the power transmission cutoff state). The predetermined slip state of the clutch C1 is a state equivalent to a disengaged state in which there is a slight slip but little engagement load is generated, that is, there is almost no torque transmission capacity.

Specifically, the neutral control condition determination unit, that is, the neutral control condition determination unit 126 determines whether or not a predetermined neutral control condition is satisfied at the travel position of the shift lever 96, for example. That is, the neutral control condition determining unit 126 is a neutral control execution determining unit that sequentially determines whether or not to start execution of neutral control by determining whether or not a predetermined neutral control condition is satisfied. The predetermined neutral control condition is, for example, that the vehicle 10 is stopped, the accelerator pedal 78 is not depressed, and the foot brake pedal 92 is depressed. For example, when the lever position P _SH is the “D” position, the neutral control condition determining means 126 is a predetermined vehicle speed zero determination value for determining whether the vehicle is stopped, and the accelerator opening Acc is accelerator-off. It is determined that the neutral control condition is satisfied when a predetermined opening degree determination value for determination and a signal indicating operation (ON) B _ON is output from the brake switch 90.

Further, the neutral control condition determining means 126 determines whether or not to release (end) the neutral control by determining whether or not the predetermined neutral control condition is satisfied during the neutral control by the neutral control means 128 described later. This is also a neutral control release determination means for sequentially determining whether or not to return from neutral control. For example, the neutral control condition determining means 126 is a predetermined value that determines that, for example, the lever position P _SH is operated from the “D” position or the accelerator pedal 78 is depressed during the neutral control by the neutral control means 128. When the brake opening degree is equal to or greater than the accelerator opening determination value or when the brake switch 90 no longer outputs a signal indicating the operation (ON) B _ON , the start of neutral control release is determined.

  For example, when the neutral control condition determination unit 126 determines that the predetermined neutral control condition is satisfied at the “D” position of the shift lever 96, the neutral control unit, that is, the neutral control unit 128 changes the first speed gear stage. A neutral control execution command for setting the clutch C1, which is an engagement device to achieve, to a predetermined slip state or release state is output to the shift control means 124, and the power transmission path including the automatic transmission 12 is set to the power transmission suppression state or Neutral control is executed to shut off the power transmission. In accordance with the neutral control execution command, the shift control means 124 hydraulically issues a clutch release command for reducing the engagement pressure of the clutch C1 according to a predetermined release pattern that is predetermined so as to place the clutch C1 in a predetermined slip state or release state. Output to the control circuit 100. When the power transmission in the automatic transmission 12 is suppressed or interrupted (released), the load on the rear stage (downstream side) of the torque converter 32 is suppressed, and the torque converter 32 rotates substantially integrally so that the engine 30 rotates. The idling load of the vehicle is suppressed, and fuel efficiency and NVH (noise / vibration / riding comfort) performance are improved. As described above, in the neutral control, the clutch C1 is brought into a released state (or a state just before engaging so as to be slightly slip-engaged), so that the power transmission path in the automatic transmission 12 is substantially released. At the same time, a start standby state in which the vehicle can start immediately by switching from half-engagement to engagement of the clutch C1 is set.

The neutral release control unit, that is, the neutral release control unit 130 includes the automatic transmission 12 when the neutral control condition determination unit 126 determines that the neutral control release start is performed during the neutral control by the neutral control unit 128, for example. A neutral control release command for engaging the clutch by increasing the torque transmission capacity of the clutch C1, which is the engagement side engagement device of the first gear stage, is set to the shift control means 124 so that the power transmission path is in a power transmission enabled state. To output (cancel) the neutral control, that is, return from the neutral control. In accordance with the neutral control release command, the shift control means 124 hydraulically outputs a clutch engagement command for increasing the engagement hydraulic pressure P _C1 of the clutch C1 according to a predetermined engagement pattern that is set in advance so that the clutch C1 is engaged. Output to the control circuit 100.

Here, the predetermined engagement pattern at the time of releasing the neutral control (at the time of releasing the neutral control), that is, the hydraulic pressure command value of the clutch C1 will be examined. When for example, the neutral control is canceled by the brake-off remains accelerator-off yet, since the engine torque T _E is not increased, even if immediately engaged the clutch C1, the occurrence of engagement shock is suppressed . Therefore, as a predetermined engagement pattern at the time of normal release of the accelerator-off, as shown in FIG. 9, the rotation of the sun gear S3 in which the turbine rotational speed _NT is restricted to the vehicle speed V as the rotational speed on the output side of the clutch C1. to decrease rapidly toward the speed _{N S3,} i.e. to face the differential rotation speed _{ΔN C1 (= N T -N S3} ) is rapidly zero between the input and the output of the clutch C1, the torque transmission capacity of the clutch C1 ( The engagement hydraulic pressure P _C1 ) is increased to obtain a hydraulic pressure command value for engagement.

In FIG. 9, as the hydraulic pressure command value for the clutch C1 at the time of releasing the accelerator-off neutral control, first, the hydraulic pressure command value for first fill (rapid filling) is started to be output (at time t1), and then at a low pressure. _Is maintained at the low-pressure standby pressure P _WL for this purpose (from time t2 to time t4). When the clutch C1 starts to have a torque transmission capacity and the turbine rotation speed _NT starts to decrease when the low pressure standby pressure _PWL is set (at time t3), the differential rotation speed ΔN _C1 is reduced while suppressing the engagement shock. A hydraulic pressure command value that gradually increases from the low-pressure standby pressure _PWL is output at a predetermined gradient for increasing the torque transmission capacity of the clutch C1 so that the clutch C1 is engaged so that the clutch C1 is engaged (at time t4). To t5). When the differential rotation speed .DELTA.N _C1 is zero, is a hydraulic command value for obtaining a final engagement pressure P _C1 (t5 after the time).

The rotational speed N _S3 of the sun gear S3 is different from the input rotational speed N _IN of the agreement between the turbine rotational speed N _T, since the input rotational speed N _IN of the same rotational speed by the engagement of the clutch C1, the automatic It can also be regarded as the input rotational speed of the transmission 12. Thus, in this embodiment, the rotational speed of the input shaft 26 as an input rotational speed N _IN, the rotation speed N _S3 of the sun gear S3 and the transmission input rotational speed N _S3. Also, the transmission input side rotational speed _NS3 may be detected directly using a rotational sensor, like the turbine rotational speed _NT, etc., but the electronic control unit 120 determines the output rotational speed _NOUT and the automatic transmission. The transmission input side rotational speed N _S3 (= γGS × N _OUT ) may be calculated based on the transmission gear ratio γGS at the current 12 gear stage GS.

On the other hand, for example, at the time of cancellation of neutral control with accelerator-on, the engine torque T _E increases with a certain response delay in accordance with the increase of the accelerator opening Acc. In this case, increasing the engaging pressure P _C1 in the hydraulic pressure command value when the accelerator is off, as shown in FIG. 9, for example to quickly engage the clutch C1 before the rise of the engine torque T _E, final and the torque transmitting capacity of the clutch C1 becomes higher already before engagement, in the occurrence of inertia torque due to the turbine rotational speed N _T is promptly reduced, the driving force does not depend on the engine torque T _E is in front engagement appear. Then, although after engagement of the clutch C1 driving force by the transmission of the engine torque T _E is generated, the driving force after engagement is when the driving power of the front engagement is relatively large (acceleration) possibly drops once There is. Therefore, as a predetermined engagement pattern at the time of releasing the neutral control accompanied by accelerator-on, as shown in FIG. 10, the turbine rotational speed _NT is once blown up to suppress the drop of the output torque after the engagement. Thereafter, the turbine rotational speed _NT and the transmission input side rotational speed _NS3 (the rotational speed NS3 of the sun gear _S3 ) are brought closer to each other with a predetermined rotational change, that is, the differential rotational speed between the input and output of the clutch C1. The torque transmission capacity (engagement oil pressure P _C1 ) of the clutch C1 is increased to be a hydraulic pressure command value to be engaged so that ΔN _C1 (= N _T −N _S3 ) goes to zero with a predetermined rotation change.

In FIG. 10, as the hydraulic pressure command value for the clutch C1 when the neutral control with accelerator-on is released, first, the hydraulic pressure command value for first fill (rapid filling) is started to be output as in the case of the normal release in FIG. Next, the pressure is maintained at the low pressure standby pressure P _WL for waiting at a low pressure (time t2 to time t4). Clutch C1 when there is a low standby pressure P _WL is beginning to have a torque transmission capacity and begins to decrease the turbine speed N _T (t3 time point), then, racing of the engine rotational speed N _E corresponding to the accelerator-on the second is maintained low standby pressure P _WL2 for waiting for the racing of the turbine rotational speed N _T as blown up the turbine rotational speed N _T with the (t4 time to time point t5). After the turbine speed N _T is blown up, the hydraulic pressure command value increases rapidly from the second low standby pressure P _WL2 for increased quickly the engagement pressure P _C1 toward the engagement of the clutch C1 is outputted (t5 time ), then blown up turbine rotational speed N oil pressure command value gradually increasing for increasing the engagement pressure P _C1 to reduce the _T is output (t5 time to time t6). Thereafter, when the differential rotational speed ΔN _C1 is reduced, the differential rotational speed ΔN _C1 is set to zero at a predetermined rotation change obtained in advance for engagement while suppressing the engagement shock. is a hydraulic command value for causing the engaging pressure _{P C1} changes (pressure regulation) is the feedback control based on .DELTA.N _C1 (t6 time to time t7). When the differential rotational speed ΔN _C1 is set to zero and the clutch C1 is engaged, the feedback control is terminated to obtain a hydraulic pressure command value for obtaining the final engagement hydraulic pressure P _C1 (time t7). Or later).

By the way, when the clutch C1 having the cushion plate 68 is engaged as in the present embodiment, the actual clutch pressure P _C1 (actual clutch pressure P _C1 ) when the piston 58 presses the friction engagement element 52 is In the process of crushing the cushion plate 68, the hydraulic pressure mainly acting to crush the cushion plate 68 and the hydraulic pressure acting to press the friction engagement element 52 itself (that is, to increase the torque transmission capacity). Hydraulic pressure). Then, the hydraulic component in the process of increasing the oil pressure command value gradually increases the actual clutch pressure P _C1, until the cushion plate 68 as possible fully collapsed, acting on the friction engagement element 52 by the shape change of the cushion plate 68 Controllability (following performance with respect to the hydraulic pressure command value) may be reduced. In other words, until the cushion plate 68 is completely crushed, even if the hydraulic pressure command value is increased and the actual clutch pressure _PC1 is increased, the hydraulic pressure acting on the cushion plate 68 is taken and applied to the friction engagement element 52. Therefore, there is a possibility that the difference between the hydraulic pressure acting on the friction engagement element 52 and the hydraulic pressure command value (or the actual clutch pressure P _C1 ) may increase. Therefore, when the cushion plate 68 at some point the process of actual clutch pressure P _C1 rises hangs fully collapsed, since the actual clutch pressure P _C1 is exclusively hydraulic component which acts on the friction engagement elements 52, results to the hydraulic component acting to the friction engagement element 52 will be caused to jump to the actual clutch pressure P _C1. Such a phenomenon occurs in a process in which the actual clutch pressure _PC1 is suddenly increased in association with a rapid increase in the hydraulic pressure command value, for example, from time t5 to time t5 'in FIG. 10 from the second low pressure standby pressure _PWL2. Then, the hydraulic pressure acting on the friction engagement element 52 is suddenly raised and the clutch C1 is suddenly engaged, and the engagement shock may be increased by a sudden inertia change at that time. That is, in the clutch C1, the cushion collapse hydraulic pressure P _CPF corresponding to the cushion load F _CP for crushing the cushion plate 68 in the process in which the actual clutch pressure P _C1 is rapidly increased after the second low pressure standby pressure P _WL2 is the cushion plate 68. As a result, the hydraulic pressure acting on the friction engagement element 52 is suddenly increased, and the engagement shock may be increased.

Therefore, in this embodiment, when raising the clutch pressure Pc for engaging the clutch C1 at the time of cancellation of the neutral control, in order to suppress the occurrence of engagement shock, crush cushion corresponds to cushion the load F _CP The increase of the clutch pressure Pc is temporarily waited at the immediately preceding standby pressure P _WDB immediately before the hydraulic pressure _CPPF acts on the cushion plate 68. For example, when the clutch pressure Pc is increased again after the second low-pressure standby pressure _PWL2 as a predetermined engagement pattern at the time of releasing the neutral control with the accelerator on, the clutch pressure Pc is increased at the immediately preceding standby pressure _PWDB. Wait temporarily. Thus, the difference between the actual clutch pressure Pc and the cushion collapse pressure P _CPF immediately before the standby pressure P _WDB is small, rapid increase in the hydraulic component acting on the frictional engaging element 52 when the cushion plate 68 is crushed Increases from the vicinity of the immediately preceding standby pressure P _WDB , and the sudden increase in hydraulic pressure acting on the friction engagement element 52 is reduced as compared with the increase from the vicinity of the second low pressure standby pressure P _WL2 . The cushion load F _CP is, for example, a specification obtained experimentally or design in advance for crushing the cushion plate 68, and the cushion collapse hydraulic pressure P _CPF is, for example, an engagement hydraulic pressure P _C1 corresponding to the cushion load F _CP. advance is experimentally or designed to oil pressure value obtained immediately before standby pressure P _WDB is experimentally beforehand as the hydraulic pressure command value with a predetermined margin (safety margin, margin) to the hydraulic P _CPF crushed cushion, for example, as a The hydraulic pressure value is smaller than the cushion collapse hydraulic pressure _PCPF obtained by design or design.

  More specifically, returning to FIG. 6, the accelerator operation determination unit, that is, the accelerator operation determination means 132 is based on, for example, whether or not the accelerator opening Acc exceeds a predetermined opening zero determination value for determining accelerator off. Thus, it is determined whether or not the accelerator pedal 78 has been depressed when the neutral release control means 130 releases the neutral control, that is, whether or not the accelerator is on.

Neutral release progression determination unit i.e. neutral release progress determining means 134, for example, in release process of neutral control by the neutral cancellation control unit 130, the engine rotational speed N whether i.e. the engine rotational speed N _{E E} blew start rising Determine whether or not. For example, neutral release progress determining unit 134, based on whether or not a predetermined change amount .DELTA.N E _'or for variation .DELTA.N _E of the engine rotational speed N _E to determine the increase start of the engine rotation speed N _E Thus, it is determined whether or not the engine rotation speed _NE has started to increase. Here, the amount of change in the engine rotational speed N _E at .DELTA.N _E, for example control the sequence is repeatedly executed on an extremely short cycle time of about several msec to several tens msec, a change in effect of the engine rotational speed N _E Treat as agreement with speed (dN _E / dt). Therefore, whether or not the change amount .DELTA.N _E of the engine rotational speed N _E reaches a predetermined change amount .DELTA.N E _'or, in effect, the rate of change of the engine rotational speed N _E (dN _{E /} dt) is given It can be regarded as the change rate whether a (dN E _/ dt) 'above.

Further, the neutral release progress determination means 134 determines whether or not the turbine rotational speed _NT has been blown, that is, whether or not the turbine rotational speed _NT has started to rise in the neutral release cancellation process by the neutral release time control means 130, for example. judge. For example, neutral release progress determining unit 134, based on whether the change amount .DELTA.N _T of the turbine rotational speed N _T is a predetermined amount of change .DELTA.N T _'or for determining the increase start of the turbine rotational speed N _T Then, it is determined whether or not the turbine rotation speed _NT has started to increase. Incidentally, the variation .DELTA.N _T of the turbine rotational speed N _T here, for example, control over which is repeatedly executed with an extremely short cycle time of several msec to several tens msec, a change in effect of the turbine rotational speed N _T Treat as agreement with speed (dN _T / dt). Therefore, the turbine rotational speed N _T variation .DELTA.N _T is whether or not a predetermined change amount .DELTA.N T _'or is substantially, the rate of change of the turbine rotational speed N _T (dN _{T /} dt) is given It can also be seen whether or not the rate of change (dN _T / dt) ′ is exceeded.

Further, the neutral release progress degree determination means 134 determines whether or not the engagement of the clutch C1 has been completed in the neutral control release process by the neutral release time control means 130, for example. For example, the neutral release progress degree determination means 134 determines a predetermined differential rotation zero determination value for determining whether the differential rotation speed ΔN _C1 (= N _T −N _S3 ) between the input and output of the clutch C1 is complete. It is determined whether or not the engagement of the clutch C1 is completed based on whether or not.

If it is determined by the accelerator operation determination means 132 that the accelerator is not turned on, the shift control means 124 engages the clutch C1 according to a predetermined engagement pattern when the accelerator is normally released as shown in FIG. It outputs a clutch engagement command to raise the P _C1 to the hydraulic control circuit 100. On the other hand, when it is determined by the accelerator operation determination means 132 that the accelerator is turned on, the shift control means 124 increases the engagement hydraulic pressure P _C1 of the clutch C1 according to a predetermined engagement pattern when the neutral control with accelerator on is released. A clutch engagement command is output to the hydraulic control circuit 100.

For example, when it is determined that the accelerator is turned on by the accelerator operation determination unit 132, the shift control unit 124 gradually increases from the low-pressure standby pressure _PWL with a predetermined gradient after the turbine rotation speed _NT starts to decrease. Instead of the hydraulic pressure command value when the accelerator is normally released, the hydraulic pressure command value that is maintained at the second low pressure standby pressure _PWL2 after the low pressure standby pressure _PWL is output to the hydraulic pressure control circuit 100. Further, the shift control means 124 performs the first fill (rapid filling) from the second low-pressure standby pressure _PWL2 when the neutral release progress determination means 134 determines that the engine speed _NE has started to increase. Following the hydraulic pressure command value, the hydraulic pressure command value that is maintained at the standby pressure P _WDB immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68 is output to the hydraulic pressure control circuit 100. Further, the shift control means 124, when the turbine rotational speed N _T is determined to have started rising by the neutral release progress determining unit 134, rapidly increases the engagement pressure P _C1 toward the engagement of the clutch C1 The hydraulic pressure command value rapidly increasing from the immediately preceding standby pressure P _WDB for causing the hydraulic pressure control circuit 100 to output is output to the hydraulic pressure control circuit 100. Further, when the neutral release progress determination unit 134 determines that the engagement of the clutch C1 is completed, the shift control unit 124 changes the engagement hydraulic pressure P _C1 by feedback control based on the differential rotation speed ΔN _C1 . instead of the hydraulic pressure command value for, it outputs a hydraulic pressure command value for obtaining a final engagement pressure P _C1 to the hydraulic control circuit 100.

  FIG. 11 is a flowchart illustrating a control operation of the electronic control device 120, that is, a control operation for suppressing an engagement shock caused by the cushion plate 68 being crushed when the neutral control is canceled. It is repeatedly executed with an extremely short cycle time of about several tens of msec. At the start of the flowchart of FIG. 11, it is assumed that neutral control by the neutral control means 128 is being executed. FIG. 12 is a time chart corresponding to the control operation of FIG.

In FIG. 11, first, in S10 corresponding to the neutral control condition determining means 126, it is sequentially determined whether or not to cancel the neutral control by determining whether or not the predetermined neutral control condition is satisfied. That is, it is sequentially determined whether or not the return control from the neutral control is started. If the determination in S10 is negative, this routine is terminated. If the determination is positive, in S20 corresponding to the neutral release time control means 130 and the shift control means 124, for example, a neutral control release command for engaging the clutch C1. Is output, and the neutral control is released, that is, the return from the neutral control is started (time t1 in FIG. 12). At this point in time, the accelerator-on state has not yet been determined. Therefore, the predetermined relationship at the time of normal release of the accelerator-off state as shown in FIG. 9 is set in advance so as to engage the clutch C1 in accordance with the neutral control release command. clutch engagement command to raise the engagement pressure P _C1 of the clutch C1 according engagement pattern is output to the hydraulic control circuit 100. For example, a hydraulic pressure command value for first fill (rapid filling) is started to be output (at time t1 in FIG. 12), and subsequently, a hydraulic pressure command value to be maintained at the low-pressure standby pressure _PWL is output (t2 in FIG. 12). Time). Next, in S30 corresponding to the accelerator operation determination means 132, it is determined whether or not the accelerator is turned on, for example, based on whether or not the accelerator opening Acc exceeds a predetermined opening zero determination value. If the determination in S30 is negative, in S40 corresponding to the shift control means 124, for example, according to a predetermined engagement pattern at the time of normal release of accelerator-off as shown in FIG. The output of the clutch engagement command for increasing the engagement hydraulic pressure _PC1 is continued.

On the other hand, if the determination in S30 is affirmative, in S50 corresponding to the shift control means 124, for example, after the turbine rotational speed _NT starts to decrease (at time t3 in FIG. 12), the low pressure standby is performed at a predetermined gradient. instead of the hydraulic pressure command value for the normal release of the accelerator-off, which gradually increases from the pressure P _WL, so blown up the turbine rotational speed N _T with the racing of the engine speed N _E corresponding to the accelerator-on (i.e. intentionally hydraulic pressure command value to keep the second low-pressure standby pressure P _WL2 is outputted to the turbine rotational speed N _T such that blow rise to) after low standby pressure P _WL in (t4 time in Figure 12). Next, in S60 corresponding to the neutral release progress determining unit 134, for example, variation .DELTA.N _E of the engine speed N _E is engine speed N _E, based on whether or not a predetermined change amount .DELTA.N E _'or blowing It is determined whether or not. If the determination in S60 is negative, the process returns to S50. If the determination is positive, in S70 corresponding to the shift control means 124, for example, the hydraulic pressure for first fill (rapid filling) from the second low-pressure standby pressure _PWL2. A command value is output (at time t4 ′ in FIG. 12), and subsequently, a hydraulic pressure command value that is maintained at the standby pressure P _WDB immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68 is output (FIG. 12). t4 "time) of. then, in S80 corresponding to the neutral release progress determining unit 134, for example, variation .DELTA.N _T of the turbine rotational speed N _T is based on whether or not a predetermined change amount .DELTA.N T _'or turbine whether or not the rotational speed N _T blew is determined. shift control hand if if the determination in S80 is negative and the process returns to S70, but is positive In S90 corresponding to 124, for example, a hydraulic command value surge from the previous standby pressure _{P WDB} for increased quickly the engagement pressure _{P C1} toward the engagement of the clutch C1 is outputted (t5 point in FIG. 12), Subsequently, (t5 after the time of FIG. 12) which blow up turbine rotational speed N oil pressure command value gradually increasing for increasing the engagement pressure P _C1 to reduce the _T is output. then, the clutch C1 If the differential rotational speed ΔN _C1 (= N _T −N _S3 ) between the input and output is made smaller than a predetermined rotational speed difference ΔN _C1 ′ for shifting to feedback control, or the change in the differential rotational speed ΔN _C1 decreases. Turning the, in S100 which corresponds to shift control means 124, for example, the difference between the predetermined rotation change previously obtained for rotational speeds .DELTA.N _C1 is engaged while suppressing engagement shock Hydraulic pressure command value for changing the engaging pressure P _C1 (pressure regulating) by feedback control based on the differential rotation speed .DELTA.N _C1 to face the zero is outputted (t6 after the time point of FIG. 12). Then, the neutral release progresses in S110 corresponding to degrees judging means 134, for example, differential speed .DELTA.N _C1 whether the engagement of the clutch C1 has been completed based on whether or not equal to or less than a predetermined differential rotation-zero determination value is determined. the If S110 the determination is negative are present routine is ended to return to the S100 but is positive. for example, when the completion of the engagement of the clutch C1 is determined by differential speed .DELTA.N _C1 becomes zero, hydraulic pressure command value for obtaining a final engagement pressure P _C1 is feedback control terminates in the S100 is output (t7 after the time point of FIG. 12).

As described above, according to this embodiment, when raising the clutch pressure Pc for engaging the clutch C1 at the time of cancellation of the neutral control is equivalent to the cushion load F _CP for crushing the cushion plate 68 Since the increase in the clutch pressure Pc is temporarily waited by the standby pressure P _WDB immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68, the friction engagement element 52 when the cushion plate 68 is crushed is used. A sudden increase in the hydraulic pressure that acts (the hydraulic pressure that presses the friction engagement element 52) increases from the vicinity of the immediately preceding standby pressure _PWDB . For example, the immediately prior standby pressure P immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68. increase in clutch pressure Pc in _WDB is caused to directly increase without being allowed to temporarily wait cushion plate 68 As compared with the case where crushed, hydraulic component spike amount is small has been engaging shock action is suppressed to the friction engagement element 52. As described above, when the clutch pressure Pc is increased in order to engage the clutch C1 when the neutral control is released, it is possible to suppress the engagement shock caused by the cushion plate 68 being crushed.

Further, according to this embodiment, at the time of cancellation of neutral control with accelerator-on, it is maintained at the second low standby pressure P _WL2 to temporarily blow up the turbine rotational speed N _T after low standby pressure P _WL, thereafter the clutch C1 the clutch pressure Pc toward the engagement is raised again from the second low standby pressure P _WL2, input and output of the clutch C1 as the rotational speed N _S3 of the turbine rotation speed NT and the sun gear S3 close slowly at a predetermined rotation change Since the clutch pressure Pc is changed by feedback control based on the difference rotational speed ΔN _C1 (= N _T −N _S3 ), it is possible to suppress a drop in output torque (acceleration) after engagement of the clutch C1. . In addition, when increasing again clutch pressure Pc from the second low-pressure standby pressure P _WL2 toward the engagement of the clutch C1, the cushion collapse pressure P _CPF corresponding to cushion the load F _CP is immediately before acting on the cushion plate 68 Since the increase of the clutch pressure Pc is temporarily waited at the immediately preceding standby pressure P _WDB , the sudden increase of the hydraulic pressure acting on the friction engagement element 52 is reduced and the engagement shock is appropriately suppressed.

  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 the above-described embodiment, the immediately preceding standby pressure P _WDB is a cushion that is uniformly set as a hydraulic pressure command value having a predetermined margin (safety width, margin) with respect to the cushion collapse hydraulic pressure P _CPF corresponding to the cushion load F _CP. The oil pressure value was smaller than the collapse oil pressure _PCPF . By the way, in order to suppress the engagement shock caused by the collapse of the cushion plate 68 as much as possible, for example, it is desirable to set the immediately preceding standby pressure P _WDB to a hydraulic pressure just before the cushion collapse hydraulic pressure _PCPF acts on the cushion plate 68. but, setting the immediately preceding standby pressure P _WDB to barely without taking a margin for cushioning collapsing pressure P _CPF, individual differences of the cushion load F _CP etc. (product variation) lower the like cushion load F _CP is small because of the article There is a possibility that the cushion collapse hydraulic pressure _PCPF will be exceeded during the standby at the set immediately preceding standby pressure P _WDB and a corresponding engagement shock will occur.

Therefore, in this embodiment, in addition to the above-described embodiment, the cushion collapse hydraulic pressure P _CPF corresponding to the cushion load F _CP acts on the cushion plate 68 during the temporary standby at the immediately preceding standby pressure P _WDB. Based on the change in the input side rotational speed of the clutch C1, for example, the change in the turbine rotational speed _NT , the next immediately preceding standby pressure P _WDB when temporarily waiting for the clutch pressure Pc to rise is set by learning control. In other words, by detecting the immediately preceding standby pressure P change of the turbine rotational speed N _T which change corresponding to the occurrence of engagement shock due to exceeding the cushion collapse pressure P _CPF occurs while waiting in _WDB .DELTA.N _T, The next immediately preceding standby pressure P _WDB is appropriately corrected by learning control, and the optimum immediately preceding standby pressure P _WDB is set for each vehicle. For example, the learning control just before standby pressure P _WDB, every time immediately before the standby pressure P temporary predetermined value or more dips in the variation .DELTA.N _T of the turbine rotational speed N _T during waiting on the _WDB has occurred, the next The immediately preceding standby pressure P _WDB is reduced stepwise from the current immediately preceding standby pressure P _WDB .

More specifically, FIG. 13 is a functional block diagram for explaining a main part of the control function by the electronic control unit 120. The shock occurrence determination means 136 and the standby pressure are compared with the functional block diagram of FIG. The difference is that a learning control means 138 is provided. 13, the shock occurrence determination unit i.e. shock occurrence determination unit 136, whether a predetermined value or more dips occurs in variation .DELTA.N _T of the turbine rotational speed N _T of the temporary waiting just before standby pressure P _WDB not Determine whether. For example, the shock occurrence determination unit 136, during a predetermined time, detects a change in the predetermined value or more to the reduction side of the variation .DELTA.N _T, and a change of more than a predetermined value to the increasing side of the variation .DELTA.N _T based on whether determines whether occurred predetermined value or more dips in the variation .DELTA.N _T of the turbine rotational speed N _T. The predetermined value is used in advance to determine a change in the turbine rotational speed _NT corresponding to the occurrence of the engagement shock caused by exceeding the cushion collapse hydraulic pressure _PCPF during the temporary standby at the immediately preceding standby pressure P _WDB. This is a judgment value obtained experimentally.

Standby pressure learning control unit i.e. standby pressure learning control unit 138, drop in more than a predetermined value change amount .DELTA.N _T of the turbine rotational speed N _T during the temporary waiting immediately before standby pressure P _WDB by shock occurrence determination unit 136 Is determined to have occurred, the next immediately preceding standby pressure P _WDB is lowered by one step from the current immediately preceding standby pressure P _WDB . For example, the standby pressure learning control means 138, by setting the hydraulic pressure to reduce the predetermined pressure amount previously set as the decrease amount of one step from the current just before the standby pressure P _WDB as the next immediately before standby pressure P _WDB The next immediately preceding standby pressure P _WDB is lowered by one step from the current immediately preceding standby pressure P _WDB .

The shift control means 124 uses the immediately preceding standby pressure P _WDB set by the learning control by the standby pressure learning control means 138 to set the hydraulic pressure command value for the first fill (rapid filling) from the second low pressure standby pressure P _WL2. Subsequently, a hydraulic pressure command value that is maintained at the standby pressure P _WDB immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68 is output to the hydraulic pressure control circuit 100.

FIG. 14 is a flowchart for explaining a main part of the control operation of the electronic control unit 120, that is, a control operation for learning control of the immediately preceding standby pressure P _WDB . For example, the control operation is repeated with a very short cycle time of about several milliseconds to several tens of milliseconds. Executed. The flowchart of FIG. 14 is executed, for example, when step 70 in the flowchart of FIG. 11 is being executed, that is, when a hydraulic pressure command value that is maintained at the immediately preceding standby pressure P _WDB is being output. FIG. 15 is a time chart corresponding to the control operation of FIG.

14, first, in S200 which corresponds to the shock occurrence determination unit 136, for example, a predetermined between the time, and the change of predetermined value or more to the reduction side of the variation .DELTA.N _T of the turbine rotational speed N _T, the turbine speed N based on whether a predetermined value or more changes and is detected in _T to the increasing side of the variation .DELTA.N _T, whether the turbine rotational speed N _T predetermined value or more dips in the variation .DELTA.N _T of occurred Determined. In S210 if corresponding to the standby pressure learning control unit 138 the determination at S200 is negative, for example, used this immediately before standby pressure _{P WDB} grounds it as the next immediately before standby pressure _{P WDB.} On the other hand, when the determination in S200 is affirmed, in S220 corresponding to the standby pressure learning control unit 138, for example, the next immediately preceding standby pressure P _WDB is lowered by one step from the current immediately preceding standby pressure P _WDB . That is, the hydraulic pressure reduced predetermined hydraulic component from this immediately before standby pressure P _WDB is set as the next immediately before standby pressure P _WDB.

In FIG. 15, as shown in FIG. 15 (a), when the set immediately preceding standby pressure P _WDB is larger than the cushion collapse hydraulic pressure P _CPF corresponding to the cushion load F _CP , the standby at the immediately preceding standby pressure P _WDB is performed. If the cushion collapse pressure _PCPF is exceeded, a corresponding engagement shock is generated. In this case, by monitoring the variation .DELTA.N _T of the turbine rotational speed N _T, if the turbine rotational speed N _T of the variation .DELTA.N predetermined value or more dips in _T is determined to have a sudden change occurred, immediately before the current It is determined that the standby pressure P _WDB is too high. The lower one step next immediately before standby pressure _{P WDB} from this immediately before standby pressure _{P WDB} by learning control. By repeating this, as shown in FIG. 15B, the immediately preceding standby pressure P _WDB can be set to an optimum value.

As described above, according to this embodiment, during the temporary standby at the immediately preceding standby pressure P _WDB , the turbine rotation associated with the cushion collapse hydraulic pressure P _CPF corresponding to the cushion load F _CP acting on the cushion plate 68. based on the change amount .DELTA.N _T speed N _T, since the set by learning control for the next immediately before standby pressure P _WDB when to temporarily wait an increase in clutch pressure Pc, depends on the individual difference or the like of the cushion load F _CP Instead, the optimum immediately preceding standby pressure P _WDB for suppressing the engagement shock can be set for each vehicle.

Further, according to this embodiment, the immediately preceding learning control of standby pressure P _WDB is just before the standby pressure P temporary predetermined value or more dips in the variation .DELTA.N _T of the turbine rotational speed N _T during standby in _WDB is Each time it occurs, the next immediately preceding standby pressure P _WDB is stepped down from the previous immediately preceding standby pressure P _{WDB in} stages, so that the engagement shock is suppressed for each vehicle without being influenced by individual differences in the cushion load F _CP , etc. Therefore, it is possible to set the most suitable immediately preceding standby pressure P _WDB for the purpose.

  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, (step S70 in FIG. 11) in the illustrated embodiment, the shift control means 124, starting from the time when the engine rotational speed N _E has started rising, fast-fill from the second low standby pressure P _WL2 (rapid filling) The hydraulic pressure command value that is maintained at the standby pressure P _WDB immediately before the cushion collapse hydraulic pressure _CPPF acts on the cushion plate 68 is output to the hydraulic pressure control circuit 100 following the hydraulic pressure command value for the engine pressure N _E. It is not necessary to start from the time when the rise starts. For example, the starting point may be the time when the engine speed has increased to some extent. Further, the shift control means 124 (step S90 in FIG. 11) immediately before the engagement hydraulic pressure _PC1 is quickly increased toward the engagement of the clutch C1, starting from the time when the turbine rotation speed _NT starts to increase. Although the hydraulic pressure command value rapidly increasing from the standby pressure P _WDB is output to the hydraulic pressure control circuit 100, it is not always necessary to start from the time when the turbine rotational speed _NT starts to increase. For example, as shown in FIG. 15, the starting point may be a point in time when the turbine rotational speed _NT is blown up to some extent.

  In the above-described embodiment, the neutral control unit 128 executes neutral control at the “D” position of the shift lever 96, but may execute it at the “R” position of the shift lever 96. In this case, at least one of the brake B2 and the brake B3, which are engagement devices for achieving the reverse gear, is set to the slip state or the release state. The present invention can be applied even when neutral control is executed in such an “R” position.

  Further, the neutral control condition determining means 126 starts the neutral control release when the temperature of the clutch C1 reaches a predetermined temperature or more that impairs the durability of the clutch C1 or when the state of the predetermined temperature or more continues for a predetermined time or more. You may judge. In this way, various other conditions can be set in order to determine the start of neutral control release. The temperature of the clutch C1 may be directly detected by a temperature sensor, or may be estimated from a relative rotational speed difference of the clutch C1 in a slip state, a slip duration time, or the like.

  In the above-described embodiment, the automatic transmission 12 is an automatic transmission capable of shifting 6 forward speeds and 1 reverse speed. However, the automatic transmission 12 is not particularly limited in terms of the number of shift stages and the internal structure. It is not limited to. 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. Further, the present invention can be applied to a continuously variable transmission such as a belt type continuously variable transmission. In the case of a belt type continuously variable transmission or the like, for example, an engagement device capable of connecting / disconnecting a power transmission path between the engine and the belt type continuously variable transmission or a well-known forward / reverse switching device may be used. The present invention is applied to the provided engagement device or the like.

  In the above-described embodiment, the torque converter 32 provided with the lock-up clutch 42 is used as the fluid transmission device. However, the lock-up clutch 42 is not necessarily provided, and the torque amplifying function is not necessarily provided. No fluid coupling may be used.

  In addition, each of the above-described embodiments can be implemented in combination with each other, for example, by setting priorities.

  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.

10: Vehicle 11: Vehicle power transmission device 30: Engine 32: Torque converter (fluid transmission)
40: driving wheel 52: friction engagement element 58: piston 58a: pressing portion 68: cushion plate 120: electronic control device (hydraulic control device)
C1: Clutch (hydraulic friction engagement device)

Claims (4)

It is provided with a hydraulic friction engagement device that transmits engine power to the drive wheel side by engagement and a cushion plate that is a spring material interposed between the friction engagement element and the pressing portion of the piston. When a predetermined neutral control condition is satisfied, the hydraulic friction engagement device is brought into a slip state or a released state, and the power transmission path from the engine to the drive wheel is set to a power transmission restrained state, thereby idling the engine. A hydraulic control device for a vehicle power transmission device that executes neutral control for suppressing a load,
When the engagement pressure is increased in order to engage the hydraulic friction engagement device when the neutral control is released, a hydraulic pressure corresponding to a cushion load for crushing the cushion plate acts on the cushion plate. A hydraulic control device for a vehicle power transmission device, wherein the increase in the engagement pressure is temporarily waited at the immediately preceding standby pressure.   Based on a change in the rotational speed of the input side of the hydraulic frictional engagement device due to the hydraulic pressure corresponding to the cushion load acting on the cushion plate during the temporary standby at the immediately preceding standby pressure, 2. The hydraulic control device for a vehicle power transmission device according to claim 1, wherein the next standby pressure when temporarily waiting for the increase in the engagement pressure is set by learning control.   The standby pressure learning control is configured to set the next standby pressure to the current value every time a drop of a predetermined value or more occurs in the amount of change in the input side rotational speed during the temporary standby at the immediately preceding standby pressure. The hydraulic control device for a vehicle power transmission device according to claim 2, wherein the pressure is lowered stepwise from the standby pressure. The hydraulic friction engagement device is connected to the engine via a fluid transmission device,
When the neutral control with the accelerator on is released, the engagement pressure is made to wait for a low pressure so that the output rotation speed of the fluid transmission device increases as the engine rotation speed increases, and the output of the fluid transmission device After the rotational speed is blown up, the engagement pressure is increased again toward the engagement of the hydraulic frictional engagement device, and then the differential rotational speed between the input and output of the hydraulic frictional engagement device changes to a predetermined rotational change. The engagement pressure is changed by feedback control so as to go to zero at
When the engagement pressure is increased again after waiting for the low pressure, the increase in the engagement pressure is temporarily waited at the standby pressure immediately before the hydraulic pressure corresponding to the cushion load acts on the cushion plate. The hydraulic control device for a vehicle power transmission device according to any one of claims 1 to 3.

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