JP2007099221A - Controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress engine stall in reducing the intake air volume of an engine at deceleration of a vehicle. <P>SOLUTION: In a controller of a vehicle, an ECU executes a program including a step (S200) of controlling an electronic throttle valve so that it has the same opening as a throttle opening TH (N) at idling, when a shift range of an automatic transmission of is an N range, if the vehicle in the deceleration (YES, in S100); a step (S300) of calculating a turbine torque TT, when the throttle opening is the TH (N) and the number of engine rotations NE is the target number of rotations NET at idling in a D range; and a step (S400) of controlling the engagement force so that a torque quantity of a C1 clutch or a C2 clutch to be engaged for forming a gear stage becomes the same values as the calculated turbine torque TT in automatic transmission. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device equipped with an automatic transmission connected to an engine via a torque converter.

  In an engine (particularly a gasoline engine), fuel is injected so that a desired air-fuel ratio (for example, theoretical air-fuel ratio) is obtained with respect to the amount of air sucked into the engine (hereinafter also referred to as intake air amount). Therefore, in order to suppress the fuel to be injected and improve the fuel efficiency, there is a problem of how to reduce the intake air amount while ensuring the output necessary for driving the engine. Therefore, a technique has been proposed for reducing the amount of intake air at the time of deceleration where a large output is not required for the engine (for example, after returning from a fuel cut at the time of deceleration).

  Japanese Patent Laying-Open No. 2004-92411 (Patent Document 1) discloses a control device for an internal combustion engine (engine) that can reduce the amount of intake air and improve fuel efficiency during deceleration. The control device for an internal combustion engine described in Patent Document 1 controls an internal combustion engine in which an automatic transmission with a torque converter is connected to an output shaft. The control device includes a deceleration operation state determination unit that determines whether or not the engine is in a deceleration operation state, and a speed ratio of the torque converter (torque converter output shaft rotation speed / input shaft when the engine is in a deceleration operation state). Torque converter speed ratio detection unit that detects the rotational speed = turbine speed / engine speed) and the intake air amount of the engine is reduced in accordance with the detected speed ratio of the torque converter (the higher the speed ratio, the more suction is performed) An intake air correction amount calculation unit for calculating the intake air correction amount (to reduce the air amount), and an intake air amount correction control unit for correcting and controlling the intake air amount of the engine according to the calculated intake air correction amount. Including. If the intake air correction amount becomes “0” as a result of continuing the deceleration operation state, the intake air amount of the engine is temporarily increased.

According to the control apparatus for an internal combustion engine described in this publication, it is possible to accurately reduce the intake air amount according to the speed ratio of the torque converter at the time of deceleration, so that the required minimum air amount can be accurately reduced. For example, when the speed ratio is large and there is assistance from the vehicle side for driving the engine, the intake air amount can be further reduced. Thereby, fuel consumption can be reduced and fuel consumption can be improved. Further, as a result of continuing the deceleration operation state, from the time when the intake air correction amount becomes “0”, by performing a transient increase that temporarily increases the intake air amount of the engine, the air after the completion of the deceleration air reduction control is performed. It is possible to avoid rotation drop and engine stall due to response delay.
JP 2004-92411 A

  However, generally, since the amount of intake air is poorly responsive to changes, a transient increase that temporarily increases the amount of intake air is performed, as in the control device described in Japanese Patent Application Laid-Open No. 2004-92411. Even in such a case, the intake air amount does not increase rapidly, and the engine may stall.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce the amount of air taken into the engine when the vehicle is decelerated and to suppress the engine stall. It is to provide a control device.

  A vehicle control apparatus according to a first aspect of the invention controls a vehicle including an automatic transmission that is connected to an engine via a torque converter and that transmits a driving force by engaging a friction engagement element. The control device includes an adjustment unit for adjusting the amount of air taken into the engine, and a first unit for controlling the adjustment unit so that the operation amount of the adjustment unit becomes the first operation amount during idling. When the control means and the vehicle are decelerated, the operating amount of the adjusting means is set to the second operating amount, and the amount of air taken into the engine is smaller than when the operating amount of the adjusting means is the first operating amount. As described above, the second control means for controlling the adjusting means, and the operating amount of the adjusting means is the second operating amount, and the engine speed is required to maintain the idling state. And calculating means for calculating the output torque of the torque converter, and when the operating amount of the adjusting means is set to the second operating amount by the second control means, the torque capacity of the friction engagement element is calculating means. The output route calculated by Click to be less than, and a third control means for controlling the engaging force of the friction engagement elements.

  According to the first aspect of the invention, during idling, the operating amount of the adjusting means for adjusting the amount of air taken into the engine (for example, the opening degree of the throttle valve and the lift amount of the intake valve) is set to the first operating amount. When the vehicle is decelerating, the operating amount of the adjusting means is set to the second operating amount so that the amount of air sucked into the engine is smaller than when the operating amount of the adjusting means is the first operating amount. Thereby, the amount of intake air can be reduced to suppress the fuel injected when the vehicle is decelerated, and the fuel consumption can be improved. At this time, if the turbine speed (output shaft speed) of the torque converter decreases as the vehicle speed decreases, the engine speed decreases due to the friction torque of the torque converter. When the engine speed decreases more than necessary (for example, when the engine speed decreases to a value that is required to maintain the idle state), the engine may stall. Therefore, so that the operating amount of the adjusting means is the second operating amount and the engine speed is equal to or lower than the output torque of the torque converter in the case where the engine speed is the speed required for maintaining the idle state, The torque capacity of the frictional engagement element of the automatic transmission (torque that can be transmitted without sliding of the frictional engagement element) is controlled. As a result, when the engine speed is reduced to the speed required to maintain the idle state with the operating amount of the adjusting means being the second operating amount, the friction engagement element of the automatic transmission Can be slid. Therefore, it is possible to suppress a decrease in the turbine rotational speed as the vehicle speed decreases, and it is possible to suppress the engine rotational speed from decreasing below the rotational speed required for maintaining the idle state. As a result, it is possible to provide a vehicle control device that can suppress engine stall when reducing the amount of air taken into the engine during deceleration of the vehicle.

  In the vehicle control apparatus according to the second invention, in addition to the configuration of the first invention, the calculating means includes the output torque of the engine and the automatic transmission when the operating amount of the adjusting means is the second operating amount. Means for calculating the output torque of the torque converter based on the target engine speed during idling when the driving force can be transmitted.

  According to the second invention, the target engine speed at idling when the engine output torque when the operating amount of the adjusting means is the second operating amount and the automatic transmission can transmit the driving force. The torque capacity of the friction engagement element of the automatic transmission is controlled so as to be equal to or less than the output torque of the torque converter calculated from the above. As a result, the engine speed is reduced to the target engine speed at idling when the automatic transmission is in a state where the driving force can be transmitted with the operating amount of the adjusting means being the second operating amount. In some cases, the friction engagement element of the automatic transmission can be slid. Therefore, it is possible to suppress the turbine rotational speed from decreasing with a decrease in the vehicle speed, and to suppress the engine rotational speed from decreasing below the target rotational speed. As a result, engine stall can be suppressed when reducing the amount of air taken into the engine when the vehicle is decelerated.

  In the vehicle control apparatus according to the third aspect of the invention, in addition to the configuration of the first or second aspect, the second air amount is an operation amount of the adjusting means during idling when the automatic transmission is in the neutral state. is there.

  According to the third invention, when the vehicle is decelerated, the operation of the adjusting means during idling in the neutral state is determined from the operating amount of the adjusting means during idling when the automatic transmission is in a state capable of transmitting the driving force. The adjusting means is controlled so that the quantity becomes equal. Thereby, the amount of intake air can be reduced to suppress the fuel injected when the vehicle is decelerated, and the fuel consumption can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This vehicle is an FF (Front engine Front drive) vehicle. A vehicle other than FF may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a planetary gear unit 3000 constituting a part of the automatic transmission 2000, a hydraulic circuit 4000 constituting a part of the automatic transmission 2000, a differential gear 5000, a drive shaft 6000, Front wheel 7000 and ECU (Electronic Control Unit) 8000 are included.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 3200. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage. Instead of the automatic transmission that forms the gear stage, CVT (Continuously Variable Transmission) that changes the gear ratio steplessly may be mounted.

  The output gear of automatic transmission 2000 is meshed with differential gear 5000. A drive shaft 6000 is connected to the differential gear 5000 by spline fitting or the like. Power is transmitted to the left and right front wheels 7000 via the drive shaft 6000.

  The ECU 8000 includes a vehicle speed sensor 8002, a position switch 8006 of a shift lever 8004, an accelerator opening sensor 8010 of an accelerator pedal 8008, a stroke sensor 8014 of a brake pedal 8012, a throttle opening sensor 8018 of an electronic throttle valve 8016, An engine speed sensor 8020, an input shaft speed sensor 8022, and an output shaft speed sensor 8024 are connected via a harness or the like.

  Vehicle speed sensor 8002 detects the speed of the vehicle from the rotational speed of drive shaft 6000 and transmits a signal representing the detection result to ECU 8000. The position of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. Stroke sensor 8014 detects the stroke amount of brake pedal 8012 and transmits a signal representing the detection result to ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000.

  ECU 8000 is sent from vehicle speed sensor 8002, position switch 8006, accelerator opening sensor 8010, stroke sensor 8014, throttle opening sensor 8018, engine speed sensor 8020, input shaft speed sensor 8022, output shaft speed sensor 8024, and the like. Based on the received signal, a map and a program stored in a ROM (Read Only Memory), the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000, when shift lever 8004 is in the D (drive) position and D (drive) range is selected as the shift range of automatic transmission 2000, out of 1st to 6th gears The automatic transmission 2000 is controlled so that any one of the gear positions is formed. The automatic transmission 2000 can transmit the driving force to the front wheels 7000 by forming any one of the first to sixth gears.

  Since the shift lever 8004 is in the N (neutral) position, the automatic transmission 2000 is controlled so that the neutral state is established when the N (neutral) range is selected as the shift range of the automatic transmission 2000.

  In addition, when engine 1000 is idling (when the accelerator opening is “0”), ECU 8000 causes engine speed NE to be set to a predetermined target speed by ISC (Idle Speed Control) control. Next, the throttle opening TH is controlled.

  The throttle opening TH (N) by ISC control in the N range is smaller than the throttle opening TH (D) by ISC control in the D range. This is because when the N range is selected, the load on the engine 1000 is lower than when the D range is selected.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 3200 having an input shaft 3100 coupled to a crankshaft. Planetary gear unit 3000 includes a first set 3300 of planetary gear mechanisms, a second set 3400 of planetary gear mechanisms, an output gear 3500, a B1 brake 3610, a B2 brake 3620 and a B3 brake 3630 fixed to gear case 3600, and C1. Clutch 3640 and C2 clutch 3650, and one-way clutch F3660 are included.

  The first set 3300 is a single pinion type planetary gear mechanism. First set 3300 includes sun gear S (UD) 3310, pinion gear 3320, ring gear R (UD) 3330, and carrier C (UD) 3340.

  Sun gear S (UD) 3310 is coupled to output shaft 3210 of torque converter 3200. Pinion gear 3320 is rotatably supported by carrier C (UD) 3340. Pinion gear 3320 is in mesh with sun gear S (UD) 3310 and ring gear R (UD) 3330.

  Ring gear R (UD) 3330 is fixed to gear case 3600 by B3 brake 3630. Carrier C (UD) 3340 is fixed to gear case 3600 by B1 brake 3610.

  The second set 3400 is a Ravigneaux type planetary gear mechanism. The second set 3400 includes a sun gear S (D) 3410, a short pinion gear 3420, a carrier C (1) 3422, a long pinion gear 3430, a carrier C (2) 3432, a sun gear S (S) 3440, and a ring gear R. (1) (R (2)) 3450.

  Sun gear S (D) 3410 is coupled to carrier C (UD) 3340. Short pinion gear 3420 is rotatably supported by carrier C (1) 3422. Short pinion gear 3420 is in mesh with sun gear S (D) 3410 and long pinion gear 3430. Carrier C (1) 3422 is coupled to output gear 3500.

  Long pinion gear 3430 is rotatably supported by carrier C (2) 3432. Long pinion gear 3430 is in mesh with short pinion gear 3420, sun gear S (S) 3440, and ring gear R (1) (R (2)) 3450. Carrier C (2) 3432 is coupled to output gear 3500.

  Sun gear S (S) 3440 is coupled to output shaft 3210 of torque converter 3200 by C1 clutch 3640. Ring gear R (1) (R (2)) 3450 is fixed to gear case 3600 by B2 brake 3620 and connected to output shaft 3210 of torque converter 3200 by C2 clutch 3650. The ring gear R (1) (R (2)) 3450 is connected to the one-way clutch F3660, and cannot rotate when the first gear is driven.

  The one-way clutch F3660 is provided in parallel with the B2 brake 3620. That is, the outer race of the one-way clutch F3660 is fixed to the gear case 3600, and the inner race is connected to the ring gear R (1) (R (2)) 3450 via the rotation shaft.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating each brake and each clutch with the combinations shown in this operation table, a forward gear stage of 1st to 6th speed and a reverse gear stage are formed.

  As shown in FIG. 3, the C1 clutch 3640 is engaged in all gears from the first gear to the fourth gear. That is, it can be said that the C1 clutch 3640 is an input clutch in the first gear to the fourth gear. C2 clutch 3650 is engaged at the fifth and sixth gears. In other words, it can be said that C2 clutch 3650 is an input clutch in the fifth and sixth gears.

  The main part of the hydraulic circuit 4000 will be described with reference to FIG. The hydraulic circuit 4000 is not limited to the one described below.

  The hydraulic circuit 4000 includes an oil pump 4004, a primary regulator valve 4006, a manual valve 4100, a solenoid modulator valve 4200, an SL1 linear solenoid (hereinafter referred to as SL (1)) 4210, and an SL2 linear solenoid (hereinafter referred to as “the solenoid valve”). 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SLT linear solenoid (hereinafter referred to as SL (2)). , SLT) 4300 and a B2 control valve 4500.

  Oil pump 4004 is connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump 4004 is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 4004 is regulated by the primary regulator valve 4006 to generate a line pressure.

  Primary regulator valve 4006 operates using the throttle pressure regulated by SLT 4300 as a pilot pressure. The line pressure is supplied to the manual valve 4100 via the line pressure oil passage 4010.

  Manual valve 4100 includes a drain port 4105. From the drain port 4105, the oil pressure in the D range pressure oil passage 4102 and the R range pressure oil passage 4104 is discharged. When the spool of the manual valve 4100 is in the D position, the line pressure oil passage 4010 and the D range pressure oil passage 4102 are communicated, and hydraulic pressure is supplied to the D range pressure oil passage 4102. At this time, the R range pressure oil passage 4104 and the drain port 4105 are communicated, and the R range pressure of the R range pressure oil passage 4104 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the R position, the line pressure oil passage 4010 and the R range pressure oil passage 4104 are communicated, and the oil pressure is supplied to the R range pressure oil passage 4104. At this time, the D range pressure oil passage 4102 and the drain port 4105 are communicated, and the D range pressure in the D range pressure oil passage 4102 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the N position, both the D range pressure oil passage 4102 and the R range pressure oil passage 4104 are connected to the drain port 4105, and the D range pressure and R of the D range pressure oil passage 4102 are communicated. The R range pressure of the range pressure oil passage 4104 is discharged from the drain port 4105.

  The hydraulic pressure supplied to the D range pressure oil passage 4102 is finally supplied to the B1 brake 3610, the B2 brake 3620, the C1 clutch 3640, and the C2 clutch 3650. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3620.

  The solenoid modulator valve 4200 adjusts the hydraulic pressure (solenoid modulator pressure) supplied to the SLT 4300 to a constant pressure using the line pressure as the original pressure.

  SL (1) 4210 regulates the hydraulic pressure supplied to the C1 clutch 3640. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3650. SL (3) 4230 regulates the hydraulic pressure supplied to the B1 brake 3610. SL (4) 4240 regulates the hydraulic pressure supplied to the B3 brake 3630.

  The SLT 4300 adjusts the solenoid modulator pressure in accordance with a control signal from the ECU 8000 based on the accelerator opening detected by the accelerator opening sensor 8010, and generates a throttle pressure. The throttle pressure is supplied to the primary regulator valve 4006 via the SLT oil passage 4302. The throttle pressure is used as a pilot pressure for the primary regulator valve 4006.

  SL (1) 4210, SL (2) 4220, SL (3) 4230, SL (4) 4240, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies the hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3620. A D range pressure oil passage 4102 and an R range pressure oil passage 4104 are connected to the B2 control valve 4500. The B2 control valve 4500 is controlled by the hydraulic pressure supplied from the SL solenoid valve (not shown) and the SLU solenoid valve (not shown) and the biasing force of the spring.

  When the SL solenoid valve is off and the SLU solenoid valve is on, the B2 control valve 4500 is in the state on the left side in FIG. In this case, the B2 brake 3620 is supplied with the hydraulic pressure adjusted from the D range pressure using the hydraulic pressure supplied from the SLU solenoid valve as a pilot pressure.

  When the SL solenoid valve is on and the SLU solenoid valve is off, the B2 control valve 4500 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the B2 brake 3620.

  With reference to FIG. 5, a control structure of a program executed by ECU 8000 which is the control device according to the present embodiment will be described.

  In step (hereinafter, step is abbreviated as S) 100, ECU 8000 determines whether or not the vehicle is decelerating. For example, when the vehicle speed is decreasing, the accelerator opening is “0”, and the stroke amount of the brake pedal 8014 is not “0”, it is determined that the vehicle is decelerating. If the vehicle is decelerating (YES in S100), the process proceeds to S200. Otherwise (NO in S100), this process ends.

  In S200, ECU 8000 controls the electronic throttle valve so that it has the same opening as throttle opening TH (N) during idling (by ISC control) in N range (when shift lever 8004 is in the N position). 8016 is controlled.

  Instead of setting the same opening as the throttle opening TH (N) during idling in the N range, the throttle opening TH during idling (when the shift lever 8004 is in the D position) (D ) May be set to an arbitrary opening degree smaller than.

  In S300, ECU 8000 causes turbine torque (output torque) of torque converter 3200 when the throttle opening is TH (N) and engine speed NE is the target speed NET during idling in the D range. TT is calculated.

Turbine torque TT is calculated using output torque TE of engine 1000 and torque ratio R (R = TT / TE).
TT = R × TE (1)
It is represented by

  Therefore, the turbine torque TT is the engine output torque TE and the torque ratio R when the throttle opening is TH (N) and the engine speed NE is the target speed NET when idling in the D range. Is calculated from

Here, the output torque TE of the engine uses a capacity coefficient C (C = TE / NE ² ),
TE = C × NE ² (2)
It is represented by

By substituting equation (2) into equation (1) and substituting target engine speed NET for engine speed NE, the throttle opening is TH (N) and engine speed NE is in the D range. The turbine torque TT when the target rotational speed NET at the time of idling is
TT = R × C × NET ² (3)
It is represented by

  Here, as is well known, the torque ratio R and the capacity coefficient C are the performance curves of FIG. 6 using the turbine speed (input shaft speed NI of the automatic transmission 2000) NT and the speed ratio E of the engine speed NE as parameters. It can ask for.

  Further, as is well known, a relationship as shown in the connection diagram of FIG. 7 is established for each throttle opening TH between the engine speed NE and the turbine speed NT. That is, if the throttle opening TH and the engine speed NE are determined, the speed ratio E can be obtained by obtaining the turbine speed NT by using the connection diagram of FIG.

  The performance curve in FIG. 6 and the connection diagram in FIG. 7 are stored in advance in the memory of the ECU 8000 as maps and data. The ECU 8000 uses the connection diagram of FIG. 7 to indicate the throttle opening TH (N) when idling in the N range, and the engine speed NE becomes the target speed NET during idling in the D range. The turbine rotational speed NT is obtained. A speed ratio E is obtained from the engine speed NE (target speed NET) and the turbine speed NT. The torque ratio R and the capacity coefficient C are obtained from the speed ratio E and the performance curve of FIG. Turbine torque TT is calculated from torque ratio R, capacity coefficient C and target rotational speed NET.

  Returning to FIG. 5, in S400, ECU 8000 causes torque capacity of C1 clutch 3640 or C2 clutch 3650 (torque that can be transmitted without slipping of the clutch) to be the same value as turbine torque TT calculated in S300. In addition, the engagement force of the C1 clutch 3640 or the C2 clutch 3650 is controlled.

  When any one of the first to fourth gears is formed, the torque capacity of the C1 clutch 3640 is controlled to be the same value as the turbine torque TT calculated in S300. When the fifth speed gear stage or the sixth speed gear stage is formed, the torque capacity of the C2 clutch 3650 is controlled to be the same value as the turbine torque TT calculated in S300.

  Note that the engagement force of the C1 clutch 3640 or the C2 clutch 3650 may be controlled so that the torque capacity is smaller than the turbine torque TT. Further, the torque capacity of other clutches and brakes may be controlled to be the same value as the turbine torque TT. Further, when the CVT is mounted, the engagement force of the forward clutch that is engaged during forward traveling may be controlled. Thereafter, this process ends.

  The operation of ECU 8000 serving as the control device according to the present embodiment based on the structure and flowchart as described above will be described.

  When the vehicle is decelerating (YES in S100), even if the D range is actually selected, the electronic control is performed so that the throttle opening TH (N) during idling in the N range is obtained. The throttle valve 8016 is controlled (S200).

  Thus, the amount of air taken into engine 1000 can be reduced as compared with the case where the vehicle is decelerated at throttle opening TH (D) during idling in D range. Therefore, the amount of fuel injected according to the amount of air can be reduced, and fuel consumption can be improved.

  At this time, the turbine torque TT is calculated when the throttle opening is TH (N) and the engine speed NE is the target speed NET (S300). The engagement force of the C1 clutch 3640 or the C2 clutch 3650 is controlled so that the torque capacity of the C1 clutch 3640 or the C2 clutch 3650 becomes the same value as the turbine torque TT (S400).

  Here, as shown in FIG. 8, the turbine torque TT increases as the turbine rotational speed NT decreases. Therefore, when the engine speed NE decreases to the target engine speed NET during idling in the D range (when the turbine speed NT decreases to NT (1) in FIG. 8), the torque of the C1 clutch 3640 or the C2 clutch 3650 The turbine torque TT is larger than the capacity (T (1) in FIG. 8).

  As a result, when the engine speed NE decreases to the target engine speed NET during idling in the D range, the C1 clutch 3640 or the C2 clutch 3650 can be slid to further suppress a decrease in the turbine speed NT. As a result, it is possible to suppress the engine speed NE from decreasing below the target speed and to suppress engine stall.

  As described above, according to the ECU that is the control device according to the present embodiment, the throttle opening during deceleration of the vehicle is set to the same opening as the throttle opening TH (N) during idling in the N range. The The torque capacity of the C1 clutch or C2 clutch, which is a friction engagement element for forming a gear stage in an automatic transmission, is when the throttle opening is TH (N) and the engine speed NE is in the D range when idling. It is set to the same value as the turbine torque TT in the case of the target rotational speed NET. Thus, when the engine speed NE decreases to the target speed NET during idling as the turbine speed NT decreases, the C1 clutch or the C2 clutch can be slid. Therefore, it is possible to suppress further decrease in the turbine rotational speed NT, and to suppress the engine rotational speed NE from being equal to or lower than the target rotational speed NE during idling. As a result, engine stall can be suppressed.

  In the present embodiment, the intake air amount is adjusted by changing the throttle opening, but the intake air amount is changed by changing the lift amount and the opening / closing timing (crank angle) of the intake valve of the engine 1000. May be adjusted.

  Further, an idle speed control valve may be separately provided on the intake passage that bypasses the electronic throttle valve 8016, and the intake air amount may be adjusted by changing the opening of the idle speed control valve.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the power train controlled by ECU which is a control apparatus which concerns on embodiment of this invention. It is a skeleton figure which shows the gear train in an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows a part of hydraulic circuit in an automatic transmission. It is a flowchart which shows the control structure of the program which ECU which is a control apparatus which concerns on embodiment of this invention performs. It is a figure which shows the performance curve of a torque converter. It is a figure which shows the coupling diagram of a torque converter. It is a figure which shows the relationship between turbine rotation speed NT and engine rotation speed NE, and the relationship between turbine rotation speed NT and turbine torque TT.

Explanation of symbols

  1000 engine, 2000 automatic transmission, 3000 planetary gear unit, 3100 input shaft, 3200 torque converter, 3210 output shaft, 3610 B1 brake, 3620 B2 brake, 3630 B3 brake, 3640 C1 clutch, 3650 C2 clutch, 3660 one-way clutch F, 4000 hydraulic Circuit, 4004 Oil pump, 4006 Primary regulator valve, 4100 Manual valve, 4200 Solenoid modulator valve, 4210 SL1 linear solenoid, 4220 SL2 linear solenoid, 4230 SL3 linear solenoid, 4240 SL4 linear solenoid, 4300 SLT linear solenoid, 4500 B2 control valve, 8000 E U, 8002 Vehicle speed sensor, 8004 Shift lever, 8006 Position switch, 8008 Accelerator pedal, 8010 Accelerator opening sensor, 8012 Brake pedal, 8014 Stroke sensor, 8016 Electronic throttle valve, 8018 Throttle opening sensor, 8020 Engine speed sensor, 8022 Input shaft speed sensor, 8024 Output shaft speed sensor.

Claims (3)

A control device for a vehicle equipped with an automatic transmission that is coupled to an engine via a torque converter and transmits a driving force by engaging a friction engagement element,
Adjusting means for adjusting the amount of air taken into the engine;
First control means for controlling the adjusting means so that the operating amount of the adjusting means becomes the first operating amount at the time of idling;
When the vehicle is decelerated, the amount of air taken into the engine is smaller than when the adjustment unit operates at the second operation amount and the adjustment unit operates at the first operation amount. Second control means for controlling the adjusting means,
In order to calculate the output torque of the torque converter when the operating amount of the adjusting means is the second operating amount and the engine speed is the engine speed required to maintain the idle state. Means for calculating
When the operation amount of the adjusting unit is set to the second operation amount by the second control unit, the torque capacity of the friction engagement element is less than or equal to the output torque calculated by the calculation unit. And a third control means for controlling the engagement force of the friction engagement element.   The calculating means is configured to output the engine at an idle time when the output power of the engine and the automatic transmission can transmit driving force when the operating amount of the adjusting means is the second operating amount. The vehicle control device according to claim 1, comprising means for calculating an output torque of the torque converter based on a target rotational speed.   3. The vehicle control device according to claim 1, wherein the second operation amount is an operation amount of the adjusting means during idling when the automatic transmission is in a neutral state. 4.

Images