JP6237438B2 - Vehicle neutral control device - Google Patents

Description

  The present invention relates to a neutral control device for a vehicle capable of estimating with high accuracy an engine torque upon return from neutral control in a vehicle capable of neutral control.

  For example, when a predetermined neutral control condition such as the accelerator off, the foot brake on, and the vehicle speed zero is satisfied at the driving position, the start is provided in the power transmission path from the engine to the drive wheels. 2. Description of the Related Art There is known a vehicle neutral control device capable of performing neutral control for suppressing an idling load of an engine by setting a clutch in a slip state or a disengaged state and setting a power transmission path to a power transmission suppression state. For example, the neutral control device for a vehicle described in Patent Documents 1 to 3 is that.

  By the way, in the neutral control device as described above, when the engagement capacity of the starting clutch is increased prior to the start of the vehicle when returning from the neutral control, the actual accelerator opening is determined from the engine output torque estimation map stored in advance. The engine output torque is estimated based on the engine speed (throttle opening) and the engine speed, and the engagement clutch engagement pressure is calculated based on the turbine torque obtained from the estimated value of the engine output torque.

JP 2011-220388 A JP 2007-263346 A International Publication WO2011125612

  However, since the engine rotational speed at idling is affected by changes in the auxiliary machine load and the rotational fluctuation is large, the accuracy of the engine output torque estimated based on the engine rotational speed from the engine output torque estimation map is sufficiently high. It's hard to get. Further, in the case of torque demand type idle speed control, feedback is performed even for a minute change in engine speed, so that the engine torque is likely to fluctuate. For this reason, the difference between the actual engine torque and the estimated engine torque is large when returning from the neutral control, and the engagement is controlled by the sudden engagement or engagement delay of the starting clutch whose engagement pressure is controlled based on the estimated engine torque. There was a problem that a combined shock occurred.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle neutral control device capable of suppressing the engagement shock of the starting clutch when the vehicle starts by returning from the neutral control. Is to provide.

In order to achieve this object, the gist of the invention according to claim 1 is as follows: (a) In a vehicle including an engine, a torque converter, and a starting clutch in series, the neutral control for releasing the starting clutch when the vehicle stops. And a neutral control device for a vehicle that increases the engagement capacity of the starting clutch with the engagement pressure based on the estimated engine output torque when returning from the neutral control. When the engine is off, the engine output torque estimated value is calculated based on the output operation amount of the driver. (C) When the engine is not idle, the engine output torque is estimated based on the engine speed and the capacity coefficient of the torque converter. An output torque estimated value is calculated, and (d) upon return from the neutral control, When the driving state of the vehicle changes from idle-on to idle-off, the starting clutch engagement pressure at the time of idle-off is calculated based on the estimated engine output torque at the time of idle-on. It is determined based on the turbine torque that is gradually increased from the torque to the turbine torque at the time of idling off calculated based on the estimated value of the engine output torque at the time of idling off at a predetermined increase rate.

In this way, when there is no engine demand load when the engine is idle, the engine output torque is accurately estimated based on the capacity coefficient of the torque converter. Compared to the case where the estimated output torque value is used, the difference between the actual engine torque and the estimated engine torque is small, and the engagement capacity of the starting clutch can be increased with high accuracy before the accelerator is turned on. Start is possible. Further, when the accelerator is off with the engine demand load, the starting clutch engagement pressure is determined based on the estimated engine output torque value based on the output operation amount of the driver, but when the vehicle starts, the starting clutch Even if there is an engagement shock, there is no problem if the vehicle is intended to start. In addition, when the vehicle operating state changes from idle on (accelerator off) to idle off (accelerator on) when returning from the neutral control, the engagement pressure of the starting clutch at idle off is idle on. Gradually increased from the turbine torque at idle-on calculated based on the estimated engine output torque at the time to the turbine torque at idle-off calculated based on the estimated engine output torque at idle-off at a predetermined increase rate It is determined based on the turbine torque. In this way, the starting clutch engagement pressure increase calculated based on the turbine torque that has been transiently increased from the turbine torque at idle-on to the turbine torque at idle-off at a predetermined increase rate. Also, the occurrence of the engagement shock of the starting clutch is eliminated.

Here, preferably, when the driving state of the vehicle changes from idle-off (accelerator-on) to idle-on (accelerator-off) when returning from the neutral control , the start clutch is engaged when idle is on. The pressure is determined on the basis of the turbine torque at idling off calculated based on the estimated engine output torque at idling off. In this way, since the sudden decrease in the estimated value of the turbine torque when changing from idle-off to idle-on is eliminated, the sudden decrease in the engagement pressure of the starting clutch calculated based on the turbine torque is also eliminated. Thus, the engagement delay of the starting clutch is suppressed.

Preferably, when returning from the neutral control, the turbine torque at idle-off calculated based on the estimated engine output torque at idle-off is based on the estimated engine output torque at idle-on. If the vehicle operating state changes from idle-on to idle-off when the turbine torque is smaller than the calculated idle-on turbine torque, the idle-off turbine torque used to calculate the engagement pressure of the starting clutch A lower limit guard is applied with the turbine torque at the time of idling on. In this way, the drop in the estimated value of the turbine torque used for calculating the engagement pressure of the starting clutch is eliminated, so the sudden decrease in the engagement pressure of the starting clutch calculated based on the turbine torque is also eliminated. Thus, the delay in engagement of the starting clutch and the occurrence of the engagement shock are eliminated.

  Preferably, an automatic transmission is provided in a power transmission path from the engine to the drive wheels, and the start clutch is a clutch that establishes the first speed gear stage of the automatic transmission.

  Preferably, in the automatic transmission, the plurality of gear stages are alternatively achieved by selectively connecting the rotating elements of the plurality of sets of planetary gear devices by the engaging device, for example, forward four-stage. Various planetary gear type multi-stage transmissions having five forward speeds, six forward speeds, and more, etc., and a plurality of pairs of transmission gears that mesh with each other between two shafts. A synchronous mesh parallel two-shaft automatic transmission in which one of the gears is selectively switched to a power transmission state by a synchronizer driven by a hydraulic actuator or the like, and the transmission stage is automatically switched, and a transmission belt that functions as a power transmission member Is a belt type continuously variable transmission that is wound around a pair of variable pulleys whose effective diameter is variable and the gear ratio is continuously changed continuously, and a pair of cone members that are rotated around a common axis. Its axis A plurality of rollers that can rotate around intersecting rotation centers are pinched between the pair of cone members, and the crossing angle between the rotation center of the rollers and the shaft center is changed, so that the gear ratio changes continuously. Toroidal-type continuously variable transmission of the type to be operated, or a differential mechanism composed of, for example, a planetary gear device that distributes power from the engine to the first electric motor and the output rotating member, and an output rotating member of the differential mechanism. And a second motor, and mechanically transmits the main part of the power from the engine to the drive wheels by the differential action of the differential mechanism, and the remaining power from the engine is transferred from the first motor to the second motor. An automatic transmission in which a gear ratio is electrically changed by electrical transmission using a path, for example, a hybrid vehicle drive device that functions as an electric continuously variable transmission or the like alone or It constructed by the combined.

  Preferably, the automatic transmission is mounted on the vehicle even when the automatic transmission is a horizontal 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. A vertical installation type such as an FR (front engine / rear drive) vehicle may be used.

  Preferably, the starting clutch is interposed in a power transmission path from the engine to the drive wheels in order to bring the power transmission path into a power transmission suppression state in a slip state or a released state during neutral control. Any engagement device may be used, and when the automatic transmission is a planetary gear type multi-stage transmission, an engagement device capable of bringing the planetary gear type multi-stage transmission into a neutral state, for example, a first gear is established. In the case of an automatic transmission, such as a CVT, in which a coupling device is used and an engagement device for bringing the inside of the transmission into a neutral state is not provided, for example, a power transmission path from the engine to the automatic transmission or an automatic transmission outside the automatic transmission An engagement device capable of connecting and disconnecting the power transmission path from the drive wheel to the drive wheel is used.

  Preferably, as the starting clutch, a hydraulic friction engagement device such as a multi-plate type or a single-plate type clutch engaged by a hydraulic actuator, an electromagnetic clutch having an electromagnetic coil for adsorbing the clutch plate, or a magnetic powder type An electromagnetic clutch or the like is used. The oil pump that supplies the hydraulic oil for engaging the hydraulic friction engagement device may be driven by the engine and discharges the hydraulic oil, for example, a dedicated electric motor arranged separately from the engine, etc. It may be driven by.

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

1 is a skeleton diagram schematically illustrating a configuration of an automatic transmission provided in a vehicle according to an embodiment of the present invention. 2 is an operation table for explaining combinations of operations of friction engagement elements, that is, friction engagement devices, when a plurality of shift stages of the automatic transmission for vehicle of FIG. 1 are selectively established. It is a figure explaining schematic structure of the power transmission system from the electronic control apparatus provided in the vehicle in order to control the automatic transmission etc. with which the vehicle of FIG. 1 was equipped, and an engine to a drive wheel. FIG. 4 is a circuit diagram relating to a linear solenoid valve that controls the operation of each hydraulic actuator of clutches C1 and C2 and brakes B1 to B3 in the hydraulic control circuit of FIG. 3. It is a functional block diagram explaining the principal part of the control function of the electronic control apparatus of FIG. FIG. 6 is a diagram showing a change in turbine torque when there is no transient processing when an idle-off (accelerator-on) operation is performed during a neutral control return mode during idle-on, and a dotted line indicates an estimated turbine torque Tta at idle-on, The solid line indicates the estimated turbine torque Ttb at the time of idling off, and the broken line indicates the turbine torque Tt used for calculating the engagement torque of the starting clutch. FIG. 11 is a diagram showing a change in turbine torque when there is a transient process when an idle-off (accelerator-on) operation is performed during a neutral control return mode during idle-on, and a dotted line indicates an estimated turbine torque Tta at idle-on, The solid line indicates the estimated turbine torque Ttb at the time of idling off, and the broken line indicates the turbine torque Tt used for calculating the engagement torque of the starting clutch. FIG. 7 is a diagram illustrating a change in turbine torque when transient processing is not performed when an idle-on (accelerator-off) operation is performed during a neutral control return mode during idle-off, and corresponds to FIG. 6. FIG. 8 is a diagram illustrating a change in turbine torque when a transient process is performed when an idle-on (accelerator-off) operation is performed during a neutral control return mode during idle-off, and corresponds to FIG. 7. FIG. 7 is a diagram illustrating a change in turbine torque when there is no transient processing when an idle-off (accelerator on) operation is performed during the neutral control return mode during idle-on, and corresponds to FIG. 6. FIG. 8 is a diagram illustrating a change in turbine torque when there is a transient process when an idle-off (accelerator-on) operation is performed during a neutral control return mode during idle-on, and corresponds to FIG. 7. FIG. 6 is a control block diagram illustrating the control contents of a neutral control return process of the neutral control means of FIG. 5 that executes model-based neutral control. FIG. 4 is a flowchart for explaining a main part of the control operation of the electronic control device of FIG. 3, that is, a control operation for suppressing the occurrence of a shock accompanying the engagement of the clutch in the return process from the neutral control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram of a vehicular automatic transmission (hereinafter referred to as an automatic transmission) 10. FIG. 2 is an operation table for explaining an operation state of the friction engagement element, that is, the friction engagement device when a plurality of shift speeds are established. The automatic transmission 10 is preferably used for an FF vehicle mounted in the left-right direction (horizontal) of the vehicle, and is a single pinion type first in a transmission case 26 as a non-rotating member attached to the vehicle body. A first transmission unit 14 mainly composed of one planetary gear unit 12, a double pinion type second planetary gear unit 16 and a single pinion type third planetary gear unit 18 are mainly composed of a Ravigneaux type. The second transmission unit 20 is provided on a common axis CL, and the rotation of the input shaft 22 is shifted and output from the output rotation member 24. The input shaft 22 corresponds to an input member. In this embodiment, the input shaft 22 is a turbine shaft of a torque converter 32 as a fluid transmission device that is rotationally driven by an engine 30 that is a power source for traveling. The output rotating member 24 corresponds to the output member of the automatic transmission 10, and an output gear that meshes with the differential driven gear (large-diameter gear) 42 to transmit power to the differential gear device 40 shown in FIG. That is, it functions as a differential drive gear. The output of the engine 30 is transmitted to the pair of drive wheels 46 via the torque converter 32, the automatic transmission 10, the differential gear device 40, and the pair of axles 44 (see FIG. 3). The automatic transmission 10 and the torque converter 32 are substantially symmetrical with respect to the center line (axial center) CL, and the lower half of the center line CL is omitted in the skeleton diagram of FIG. .

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

  The automatic transmission 10 corresponds to a combination of any one of the rotational states (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) of the first transmission unit 14 and the second transmission unit 20 according to the combination. Six forward shift stages (forward gear stages) from the first shift stage “1st” to the sixth shift stage “6th” are established, and the reverse shift stage (reverse gear stage) of the reverse shift stage “R” is established. It is done. As shown in FIG. 2, for example, in the forward gear stage, the first speed gear stage is set by engagement of the clutch C1 and the brake B2 or the one-way clutch F1, and the second speed gear stage is set by engagement of the clutch C1 and the brake B1. However, the third gear is set by engagement of the clutch C1 and 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 clutch C2 and the brake B1. Further, the reverse gear stage is established by the engagement of the brake B2 and the brake B3, and the neutral state is established by releasing any of the clutches C1, C2 and the brakes B1 to B3. Since the clutch C1 of the present embodiment is engaged at the time of forward traveling from the first speed to the fourth speed, it functions as a forward clutch.

  The operation table of FIG. 2 summarizes the relationship between the above-mentioned shift speeds and the operation states of the clutches C1, C2 and the brakes B1 to B3, where “◯” indicates engagement and “◎” indicates only during engine braking. Represents the event. Particularly, since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first shift stage “1st”, only the clutch C1 is engaged and the engine brake is applied when starting (acceleration). Sometimes the clutch C1 and the brake B2 are engaged. Therefore, the so-called neutral control for suppressing the idling load of the engine 30 can be performed by setting the clutch C1 to the slipping state or the releasing state when the vehicle in which the first shift speed is established. Further, the gear ratios of the respective gear stages are the gear ratios of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18 (= number of teeth of the sun gear / number of teeth of the ring gear) ρ1, ρ2. , Ρ3 as appropriate.

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

  FIG. 3 is a block diagram illustrating a schematic configuration of a main part of a control system provided in the vehicle for controlling the automatic transmission 10 and the like of FIG. 1 and a power transmission system from the engine 30 to the drive wheels 46. .

  In FIG. 3, the electronic control unit 100 is configured to include a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface and the like, for example, and the CPU stores in the ROM in advance using the temporary storage function of the RAM. By performing signal processing according to the programmed program, the output control of the engine 30, the shift control of the automatic transmission 10, the on / off control of the lock-up clutch 34, the power transmission path in the automatic transmission 10 when the vehicle is stopped and the accelerator is off. Neutral control or the like is performed to reduce the engine load by releasing the engine, for controlling the engine, for controlling the linear solenoid valves SL1 to SL5, and for the linear solenoid valve SLU of the hydraulic control circuit 50. And a lock-up clutch that controls the solenoid valve SL. Configured divided into control and the like.

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

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

  The wheel brake device 80 shown in FIG. 3 supplies braking hydraulic pressure to a wheel cylinder WC (not shown) provided in the wheel brake in association with the operation of the foot brake pedal 68 and the like. In the wheel brake device 80, usually, a brake hydraulic pressure having a magnitude corresponding to the depression force of the foot brake pedal 68 generated in the master cylinder is directly supplied to the wheel cylinder WC. For example, ABS control, traction control, VSC control, etc. Or, at the time of so-called hill hold control that prevents the movement of the vehicle on the slope regardless of the foot brake operation, in order to hold or maintain the vehicle stopping, starting, turning traveling on the low μ road, or the vehicle stop in the middle of the slope A brake fluid pressure that does not correspond to the pedal effort is supplied to the wheel cylinder WC.

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

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

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

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

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

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

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

FIG. 5 is a functional block diagram for explaining the main part of the control function of the electronic control device 100 that also functions as a neutral control device. In FIG. 5, the engine output control means 102 controls opening and closing of an electronic throttle valve by a throttle actuator for throttle control, controls fuel injection by a fuel injection device for fuel injection control, and controls ignition timing. The output control of the engine 30 is executed by controlling the ignition timing by an ignition device such as an igniter. For example, the engine output control unit 102 drives the throttle actuator based a predetermined stored relationship of the accelerator opening Acc, the throttle control to increase the throttle valve opening theta _TH as the accelerator opening Acc is increased Run.

Further, the engine output control means 102 executes throttle control so as to control the idle rotation speed _NIDL at a target value when the vehicle is stopped or decelerated when the accelerator opening degree Acc is substantially zero (fully closed). For example, the engine output control means 102 determines the fast idle rotation speed that is set higher than the normal idle rotation speed N _IDL after warming up based on the engine coolant temperature _TW and the catalyst temperature signal from the relationship stored in advance. Throttle control is executed so that N _IDLF is obtained and that the normal idle speed N _IDL after the warm-up is obtained.

  The shift control means 104 makes a shift determination based on the actual vehicle speed V and the accelerator opening Acc based on the relationship (map, shift diagram) (not shown) stored in advance with the vehicle speed V and the accelerator opening Acc as variables, and automatically shifts. It is determined whether or not the shift of the machine 10 should be executed, for example, the shift stage to be shifted of the automatic transmission 10 is determined, and the automatic shift control of the automatic transmission 10 is executed so that the determined shift stage is obtained. . At this time, the shift control means 104 engages and / or releases the hydraulic friction engagement device involved in the shift of the automatic transmission 10 so that the shift stage is achieved according to, for example, the engagement table shown in FIG. A command (shift output, hydraulic command) is output to the hydraulic control circuit 50.

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

The neutral control condition determination unit 106 determines whether or not a predetermined neutral control condition is satisfied at the travel position of the shift lever 72. The predetermined neutral control condition is, for example, that the vehicle is stopped, the accelerator pedal 52 is not depressed, the throttle valve opening θ _TH is zero, and the foot brake pedal 68 is depressed. For example, the neutral control condition determining means 106, for example, when the lever position P _SH is the “D” position, the vehicle speed V is less than or equal to a predetermined stop determination value, the accelerator opening is zero (accelerator off), and When the brake switch 70 is ON B _ON, it is determined that the neutral control condition is satisfied, and the determination result is output to the neutral control means 108.

In addition, the neutral control condition determination unit 106 determines whether or not to release (or end) the neutral control by determining whether or not the predetermined neutral control condition is satisfied during the neutral control by the neutral control unit 108. This is also a neutral control return (cancellation) determination means for sequentially determining whether or not to start recovery from neutral control. Specifically, the neutral control condition determining means 106 performs a predetermined accelerator opening that determines that, for example, the lever position P _SH is operated from the “D” position or the accelerator pedal 52 is depressed during the neutral control. If degrees judgment value or whether a (accelerator-on), or the brake switch 70 is no longer on B _oN, determines the release start of the neutral control, and outputs the determination result to the neutral control means 108.

The estimated turbine torque calculating means 109 is configured to output the engine output based on the actual accelerator opening degree and the engine rotational speed Ne from a well-known engine output torque map stored in advance when the engine load is demanded at idle-off (accelerator-on). Torque Te is calculated, and the engine output torque Te is multiplied by the torque ratio t (Tout / Tin, that is, Tt / Te) of the torque converter 32 to calculate the estimated turbine torque Tta at the time of idling off. Further, when the engine load is not idling (accelerator off) during the neutral control recovery, the estimated turbine torque calculation means 109 calculates the capacity coefficient C of the torque converter 32 that is not affected by the operation of the auxiliary machine, etc. The engine output torque Te (= Ne ² × C) is accurately calculated by multiplying the square (square) value of the number Ne, and the engine output torque Te is multiplied by 1 or the torque ratio t of the torque converter 32. (= Tout / Tin, that is, Tt / Te) is multiplied to calculate the estimated turbine torque Ttb at the time of idling off, and the neutral control means is switched from the estimated turbine torque Tta at the time of idling on to the estimated turbine torque Ttb at the time of idling on. To 108. The torque ratio t and the capacity coefficient C are calculated based on the actual speed ratio e (= Nout / Nin, that is, Nt / Ne) from the characteristics of the torque converter 32 stored in advance. In the neutral control means 108, the estimated turbine torque Tta at the time of idling on and the estimated turbine torque Ttb at the time of idling off based on a predetermined relationship for setting the magnitude of the engagement pressure necessary and sufficient for torque transmission. Based on the above, the engagement pressure of the clutch C1 at the time of idling on and idling off is calculated. Since the estimated turbine torque Tta at the time of idling on and the estimated turbine torque Ttb at the time of idling off are calculated based on the engine output torque Te at idling on and idling off, the clutch C1 at idling on and idling off is calculated. Is calculated based on the engine output torque Te at the time of idling on and idling off.

  Estimated turbine torque calculation means 109 is smooth in order to eliminate a step (a step-like sudden change) at the time of switching from the estimated turbine torque Tta at the time of idling on to the estimated turbine torque Ttb at the time of idling off when the accelerator is turned on. Turbine torque smoothing means 110 for generating a turbine torque Tttr during transition for connection or delaying switching is provided. When an idle-off (accelerator-on) operation is performed during the neutral control return mode during idling-on, and there is no transient processing, for example, as shown in FIG. The estimated turbine torque Ttb during idle-off, which is larger than that, is increased stepwise. The turbine torque smoothing means 110 generates a transient turbine torque Tttr that linearly increases at a predetermined increase rate in order to eliminate the step between them, and the transient turbine torque Tttr is generated at idle off time. Until the estimated turbine torque Ttb is reached, the estimated turbine torque Ttb is output instead of the estimated turbine torque Ttb at the time of idle-off, and the estimated turbine torque Tt that changes gently as shown by the broken line in FIG. 7 is output. Further, when an idle-on (accelerator-off) operation is performed during the neutral control return mode during idle-off, if the transient process is not performed, for example, as shown in FIG. 8, the estimated turbine torque Ttb at the time of idle-off indicated by a solid line To the estimated turbine torque Tta at the time of idle-on indicated by a dotted line smaller than that. The turbine torque smoothing means 110 prohibits such switching to the estimated turbine torque lowering side to eliminate the step between them, and outputs the estimated turbine torque Tt indicated by the broken line in FIG. A sudden change in engagement torque and engagement delay of C1 are prevented. That is, after the idle-on operation, a max-select process for selecting and outputting the larger of the estimated turbine torque Ttb at idle-off and the estimated turbine torque Tta at idle-on is performed. Further, when an idle-off (accelerator-on) operation is performed during the neutral control return mode during the idle-on state, if there is no transient process, for example, as shown in FIG. The estimated turbine torque Ttb at the time of idling off smaller than that shown in FIG. Turbine torque smoothing means 110 eliminates the level difference between them until estimated turbine torque Ttb, which increases the switching time point at a predetermined increase rate from the idle-off time, reaches estimated turbine torque Tta at the idle-on time. The estimated turbine torque Tt that changes slowly as shown by the broken line in FIG. 11 is output and the movement in the direction opposite to the actual turbine torque is prevented. That is, after the idle-on operation, a max-select process for selecting and outputting the larger of the estimated turbine torque Ttb at idle-off and the estimated turbine torque Tta at idle-on is performed.

Returning to FIG. 5, the target turbine speed calculation means 111 is experimentally obtained in advance so as to obtain both fuel efficiency and acceleration feeling at the time of start, and based on the actual accelerator opening from the relationship stored in advance. The target turbine speed Nt ^* in the section from the accelerator-on operation at the time of vehicle start-up until the engagement of the clutch C1 is completed is sequentially calculated and output to the neutral control means 108.

When the neutral control condition determining means 106 determines that the predetermined neutral control condition is satisfied, for example, at the “D” position of the shift lever 72, the neutral control means 108 is configured to achieve the first gear. the clutch C1 is a coupling device, the shift control means a neutral command to the clutch C1 by supplying a slip state or released state of the clutch pressure P _C1 calculated by the clutch pressure control unit 126 described later to function as a clutch pressure calculator The neutral control is executed to output the power to the power transmission path including the automatic transmission 10, for example, the clutch C <b> 1 in the power transmission path of the first speed stage in a non-power transmission state. The shift control means 104 outputs to the hydraulic control circuit 50 a control signal for reducing the engagement pressure of the clutch C1 in accordance with a predetermined pattern so that the clutch C1 is in the slip state or the release state in accordance with the neutral command. . When the power transmission in the automatic transmission 10 is suppressed or cut off (released), the torque converter 32 rotates substantially integrally and the idling load of the engine 30 is suppressed, and fuel consumption and NVH (noise / vibration / riding) are reduced. Comfort) performance is improved.

The neutral control means 108 is estimated during the return of the neutral control in which the brake-off operation (return operation) is performed by the foot brake pedal 68 during the neutral control and the neutral control condition determination means 106 determines that the neutral control is released. calculating the clutch pressure P _C1 based on the turbine torque Tt calculated by the turbine torque calculation means 109, which the clutch pressure P _C1 that is higher than to be supplied to the clutch C1 engagement torque capacity of the clutch C1 Increase the standby state to start immediately. Further, when the accelerator is turned on during the return of the neutral control, the neutral control means 108 is actually (based on the turbine torque Tt calculated by the estimated turbine torque calculation means 109 and the target turbine speed Nt ^*. Estimate) The engine output torque command value and the clutch pressure _PC1 are calculated so that the turbine speed Nt follows the target turbine speed Nt ^* , and the output torque of the engine 30 and the engagement torque of the clutch C1 are controlled. The clutch C1 is smoothly and completely engaged while starting the vehicle. The clutch pressure P _C1 is calculated based on the turbine torque Tt so that sudden engagement and clutch slippage of the clutch C1 are eliminated with respect to the actual torque rising.

The neutral control means 108 executes return control from neutral control on a model basis using a hydraulic response model that outputs a time function having a predetermined time constant and an engine torque response model. FIG. 12 is a control block diagram illustrating the control contents of the neutral control return process of the neutral control means 108. In the return control from the neutral control shown in FIG. 12, with respect to the engine torque control, the engine torque FB control unit 112 determines that based on the actual deviation ΔNt between the target turbine speed Nt ^* and the actual turbine speed Nt. The engine speed FF control unit 114 outputs a rotational speed feedback control amount Tefb for canceling the torque based on the torque deviation ΔTt between the torque feedforward amount Tcff output from the clutch torque FF control unit 120 and the estimated turbine torque Tt. Based on the model deviation ΔNtm between the model turbine rotational speed Ntm output from the pre-clutch model 116 and the target turbine rotational speed Nt ^* , a rotational speed feedforward control amount Teff for reducing it is output, and the engine torque The control unit 118 controls the rotation speed. The throttle actuator (not shown) is controlled based on the total rotational speed control amount (Teff + Tefb) of the feedback control amount Tefb and the rotational speed feedforward control amount Teff, and the output of the engine 30 is such that the actual deviation ΔNt and the model deviation ΔNtm are eliminated. Control torque. Further, in the return control from the neutral control shown in FIG. 12, for the engagement torque control of the clutch C1, the clutch torque FF control unit 120 outputs the torque feedforward amount Tcff based on the model deviation ΔNtm, and the clutch torque FB The control unit 122 outputs a torque feedback amount Tcfb for canceling it based on the actual deviation ΔNt, and the clutch torque control unit 124 is a total torque control amount (Tcff + Tcfb) of the torque feedforward amount Tcff and the torque feedback amount Tcfb. The clutch internal pressure control unit 126 outputs the engagement pressure P corresponding to the total control amount based on the total torque control amount (Tcff + Tcfb) using the clutch internal pressure model 128 and the control V inverse model 130 stored in advance. _C1 to determine And supplies to the clutch C1 in the automatic transmission 10. In the present embodiment, the engine torque control unit 118 corresponds to an engine torque determination unit during neutral control, and the clutch internal pressure control unit 126 corresponds to a clutch pressure determination unit during neutral control.

  FIG. 13 is a flowchart for explaining a main part of the control operation of the electronic control apparatus 100, and is repeatedly executed with a cycle time of, for example, about several milliseconds to several tens of milliseconds.

In FIG. 13, in step S1 (hereinafter, step is omitted) corresponding to the neutral control means 108, for example, when the lever position P _SH is the “D” position, the vehicle speed V is equal to or less than a predetermined stop determination value. When the accelerator opening is zero (accelerator off) and the brake switch 70 is on B _ON , the neutral control based on the determination that the neutral control condition is satisfied is executed, and the clutch The engagement pressure of C1, that is, the engagement torque is reduced, and the power transmission path including the automatic transmission 10 is set to the non-power transmission state to reduce the load on the engine 30 in the idle-on state.

Next, in S2 corresponding to the neutral control condition determining means 106, for example, when the neutral control return start condition is satisfied by turning off the brake, the neutral control return control is started. Next, in S3 corresponding to the estimated turbine torque calculation means 109 and the clutch internal pressure control unit 126, the engine squared value of the engine speed Ne is multiplied by the capacity coefficient C of the torque converter 32 at the time of idling without an engine load request. The output torque Te is accurately calculated, and the estimated turbine torque Tt is calculated by multiplying the engine output torque Te by the torque ratio t of the torque converter 32. Based on the estimated turbine torque Tt, the clutch pressure (engagement) of the clutch C1 is calculated. application _{pressure) P C1} is calculated.

Next, at S4, whether or not the accelerator is on based on whether or not the accelerator opening Acc, which is the operation amount of the accelerator pedal 52 detected by the accelerator opening sensor 54, exceeds a preset accelerator on determination value. Is judged. When the determination in S4 is negative, in S5 corresponding to the estimated turbine torque calculation means 109 and the clutch internal pressure control unit 126, the engine speed Ne is not in the engine-on state and there is no engine load request similar to S3. The engine output torque Te is accurately calculated by multiplying the square value by the capacity coefficient C of the torque converter 32, and the estimated turbine torque Tt is calculated by multiplying the engine output torque Te by the torque ratio t of the torque converter 32, Calculation of the clutch pressure (engagement pressure) PC1 of the clutch _C1 is continued based on the estimated turbine torque Tt.

However, if the determination in S4 is affirmative, in S6 corresponding to the estimated turbine torque calculation means 109 and the clutch internal pressure control unit 126, it is an idle-off time when an engine load is requested, so that it is well known in advance. The engine output torque Te is calculated from the engine output torque map based on the actual accelerator opening and the engine speed Ne, and the estimated turbine torque Tta at the time of idling off is calculated from the engine output torque Te, and the estimated turbine torque Tt is calculated. Based on this, the clutch pressure (engagement pressure) PC1 of the clutch _C1 is calculated.

Then, the clutch pressure determined as described above (engagement pressure) P _C1 is supplied to the clutch C1 engagement of the clutch C1 is brought to completion, the neutral control is then completed.

As described above, according to the present embodiment, when the accelerator is off (idle on) without the engine demand load when idling is on, the engine output torque Te is accurate based on the capacity coefficient C of the actual torque converter 32. Since it is well estimated, the difference between the actual engine torque Te and the estimated engine torque Te is small compared to the case where an engine output torque estimated value that is influenced by the engine speed Ne and has a large variation is used from the engine output torque map. Prior to the accelerator being turned on, the torque capacity of the clutch C1 can be increased with high accuracy, and the vehicle can be started without the engagement shock of the clutch C1 (starting clutch). When the accelerator is on (idle off) with a required engine load, the clutch C1 (based on the engine output torque estimated value Te estimated from the engine output torque map based on the accelerator opening (output operation amount of the driver). Although the engagement pressure P _C1 of the starting clutch) is determined, at the start of the vehicle is the driver not a problem since the intended start even with if the starting clutch engagement shock.

Further, according to the present embodiment, when the neutral control is returned, as shown in FIG. 7, when the driving state of the vehicle changes from idle on (accelerator off) to idle off (accelerator on), The engagement pressure P _C1 of the clutch C1 (starting clutch) is an engine output torque that is gradually increased from a turbine torque Tta calculated at the time of idling to a turbine torque Ttb calculated at the time of idling off at a predetermined increase rate, that is, a transient turbine torque. It is determined based on Tttr. Thus, since the turbine torque Tta calculated at the time of idling on is smoothly increased at a predetermined increase rate from the turbine torque Tta calculated at the time of idling off, the clutch C1 (starting) calculated based on the turbine torque Tt is started. increase in the engagement pressure P _C1 of the clutch) is turned smoothly, the occurrence of engagement shock of the clutch C1 is eliminated.

Further, according to this embodiment, when the neutral control is returned, as shown in FIG. 9, when the engine is changed from idle-off (accelerator-on) to idle-on (accelerator-off), the clutch C1 (starting clutch) at the time of idle-on is changed. the engagement pressure P _C1 of the), without using the estimated turbine torque Tta idle on, is determined using the estimated turbine torque Ttb based on the engine output torque Te calculated at the time of idle off. For this reason, since the sudden decrease in the turbine torque Tt when changing from idle-off to idle-on is eliminated, the sudden decrease in the engagement pressure P _C1 calculated based on the turbine torque Tt is also eliminated, so that the clutch C1 The engagement delay of the (start clutch) is suppressed.

Further, according to this embodiment, when the neutral control is restored, as shown in FIG. 11, the estimated turbine torque Ttb based on the engine output torque Te calculated at the time of idling off is estimated based on the engine output torque Te calculated at the time of idle on. is smaller than the turbine torque Tta, if it changes from idle on to idle off, idle on the engine output torque estimated value calculated by the idle off used for calculating the engagement pressure P _C1 of the clutch C1 (start clutch) A lower limit guard is applied with the calculated estimated turbine torque Ttb. Therefore, since the drop in the estimated turbine torque Tt used for calculating the engagement pressure of the clutch C1 (starting clutch) is eliminated, also eliminating the drop in the engagement pressure P _C1 calculated based on the turbine torque Tt Therefore, the engagement delay and engagement shock of the clutch C1 are eliminated.

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

  For example, in the above-described embodiment, the torque converter 32 is provided between the engine 30 and the automatic transmission 10, but instead of the torque converter 32, a fluid coupling having no torque amplification action is provided. May be. In this case, the engine output torque Te and the turbine torque Tt have the same value.

  In the above-described embodiment, the neutral control unit 108 executes neutral control at the “D” position of the shift lever 72, but may execute it at the “R” position of the shift lever 72. 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 106 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. Note that 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.

  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: Automatic transmission 30: Engine 32: Torque converter 46: Drive wheel 100: Electronic control device (neutral control device)
108: Neutral control means 109: Estimated turbine torque calculation means C1: Clutch (starting clutch)

Claims (3)

In a vehicle having an engine, a torque converter, and a start clutch in series, neutral control is performed to release the start clutch when the vehicle is stopped, and when returning from the neutral control, the engagement pressure based on the estimated engine output torque is used. A vehicle neutral control device for increasing an engagement capacity of a starting clutch,
The engine output torque estimated value is calculated based on the output operation amount of the driver when the engine load is demanded, and based on the engine speed and the capacity coefficient of the torque converter when the engine is not idle. To calculate the estimated engine output torque,
When the driving state of the vehicle changes from idle-on to idle-off when returning from the neutral control, the engagement pressure of the starting clutch at idle-off is based on the estimated engine output torque at idle-on. To be determined based on the turbine torque obtained by gradually increasing the turbine torque at the time of idle off to the turbine torque at the time of idle off at a predetermined increase rate from the turbine torque at the time of idle on calculated in the above. A neutral control device for a vehicle. When the driving state of the vehicle changes from idle-off to idle-on when returning from the neutral control, the engagement clutch engagement pressure at the time of idle-on is based on the engine output torque estimated value at the time of idle-off. The vehicle neutral control device according to claim 1, wherein the vehicle neutral control device is determined based on the turbine torque calculated at the time of idling off. When returning from the neutral control, the idle-off turbine torque calculated based on the estimated engine output torque at idle-off is calculated based on the estimated engine output torque at idle-on. When the vehicle operating state changes from idle-on to idle-off when the turbine torque is smaller than the turbine torque of the idle clutch, the turbine torque at idle-off used for calculating the engagement pressure of the starting clutch is The vehicle neutral control device according to claim 1, wherein a lower limit guard is applied by a turbine torque.

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