JP4811195B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a technique for controlling a vehicle including an automatic transmission that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement elements. .

  2. Description of the Related Art Conventionally, there is known a vehicle including an automatic transmission that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement elements. In such an automatic transmission, when one frictional engagement element is changed from the engaged state to the released state, and another one of the frictional engagement elements is changed from the released state to the engaged state, the shift is performed. There is. In such a shift, if the friction engagement element is suddenly engaged, a shock may occur. Therefore, it is necessary to gently engage the friction engagement elements at the time of shifting.

Japanese Unexamined Patent Publication No. 2000-145940 (Patent Document 1) discloses an automatic transmission that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement elements. In the automatic transmission described in Patent Document 1, during downshifting, the hydraulic pressure of the frictional engagement element that is brought into the engaged state from the released state is increased to a hydraulic pressure necessary to fill the hydraulic chamber of the hydraulic servo, Hold for hours. When a predetermined time elapses, the hydraulic pressure is swept down to a pressure that does not generate torque capacity (engagement force) and held until a predetermined time elapses. Thereafter, the hydraulic pressure is swept up (gradually increased) with a preset gradient until a predetermined time has elapsed.
JP 2000-145940 A

  However, when the hydraulic pressure is gradually increased at a predetermined gradient as in the automatic transmission described in Japanese Patent Application Laid-Open No. 2000-145940, the engagement force becomes lower or higher with respect to the input torque of the automatic transmission. It is possible that In this case, the engine speed may increase or the shock may increase during shifting.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a vehicle control device capable of suppressing the increase in engine speed and shock during shifting. .

  According to a first aspect of the present invention, there is provided a vehicle control device that automatically connects a power source and a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement elements. A control device for a vehicle including a transmission. This control device has a setting means for setting a target hydraulic pressure in accordance with an input torque of the automatic transmission, and a difference between the input shaft rotation speed and the synchronous rotation speed of the automatic transmission is determined in advance during the downshift. Control means for controlling the hydraulic pressure supplied to the frictional engagement element that is brought into the engaged state from the released state at the time of downshifting so as to be the target hydraulic pressure when the value is smaller than the predetermined value.

  According to the first invention, the target oil pressure is set according to the input torque of the automatic transmission. During downshift execution, when the difference between the input shaft speed and the synchronous speed of the automatic transmission is smaller than a predetermined value, the target oil pressure is engaged during the downshift so that the target hydraulic pressure is reached. The hydraulic pressure supplied to the frictional engagement element to be brought into a state is controlled. Thereby, the engagement force of the friction engagement element can be set to a value corresponding to the input torque of the automatic transmission. Therefore, it can suppress that engagement force becomes low with respect to the input torque of an automatic transmission, or becomes high. As a result, it is possible to provide a vehicle control device that can suppress the engine speed increase and shock during a shift.

  In the vehicle control apparatus according to the second invention, in addition to the configuration of the first invention, the setting means includes means for setting the target hydraulic pressure based on the output shaft rotational speed of the automatic transmission.

  According to the second invention, the target hydraulic pressure is set based on the output shaft rotational speed of the automatic transmission. The input shaft rotational speed of the automatic transmission is a rotational speed corresponding to the output shaft rotational speed except during shifting. Therefore, it can be said that the input torque after the shift is a value corresponding to the output shaft rotational speed. Further, it can be said that the output shaft rotational speed interlocked with the vehicle speed is stable after the shift compared to the input shaft rotational speed that is greatly influenced by the state of the friction engagement element during the shift. The target hydraulic pressure is set based on such output shaft rotation speed. Thereby, the target hydraulic pressure corresponding to the input torque can be set with high accuracy. Therefore, the engagement force of the friction engagement element can be made to correspond to the input torque with high accuracy.

  In the vehicle control apparatus according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the setting means sets the target hydraulic pressure so as to be smaller when the output shaft rotational speed of the automatic transmission is high than when it is low. Means for setting.

  According to the third aspect of the invention, the target hydraulic pressure is set to be smaller when the output shaft rotational speed of the automatic transmission is high than when it is low. This is because when the output shaft rotational speed of the automatic transmission, that is, the input shaft rotational speed is high, the input torque is smaller than when it is low. Thereby, the target hydraulic pressure corresponding to the input torque can be set with high accuracy.

  In addition to the configuration of any one of the first to third aspects, the vehicle control device according to the fourth aspect of the invention is such that the output shaft rotational speed of the power source when the vehicle is stopped and the power source is idle is the target idle rotational speed. Means for further controlling. The setting means includes means for setting the target hydraulic pressure so that the target hydraulic pressure is larger when the target idle speed is high than when it is low.

  According to the fourth invention, the target hydraulic pressure is set to be larger when the target idle speed is high than when it is low. This is because the input torque is larger when the target idle speed is high than when it is low. Thereby, the target hydraulic pressure corresponding to the input torque can be set with high accuracy.

  The vehicle control apparatus according to a fifth aspect of the invention further includes a correction means for correcting the target hydraulic pressure in accordance with the deceleration of the vehicle, in addition to the configuration of any one of the first to fourth aspects of the invention.

  According to the fifth invention, as the vehicle speed decreases, the reaction force received by the frictional engagement element by the inertia inside the power source and the automatic transmission changes accordingly, so that the target hydraulic pressure is corrected according to the deceleration of the vehicle. . Thereby, it is possible to accurately set an appropriate target hydraulic pressure at the time of shifting.

  In the vehicle control apparatus according to the sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, the correction means corrects the target hydraulic pressure to be larger when the deceleration of the vehicle is large than when it is small. Including means.

  According to the sixth invention, when the vehicle speed decreases, the reaction force received by the frictional engagement element by the inertia inside the power source and the automatic transmission increases accordingly. Therefore, when the deceleration is large, the target is smaller than when the deceleration is small. The oil pressure is corrected so as to increase. Thereby, it is possible to accurately set an appropriate target hydraulic pressure at the time of shifting.

  According to a seventh aspect of the present invention, there is provided a vehicle control apparatus, in addition to the configuration according to any one of the first to sixth aspects, wherein the rotational speed of the automatic transmission is synchronized with the input shaft rotational speed before the hydraulic pressure is controlled to reach the target hydraulic pressure. Means are further included for controlling the hydraulic pressure in response to the difference from the number.

  According to the seventh aspect, before controlling the hydraulic pressure to reach the target hydraulic pressure, the difference between the input shaft rotation speed and the synchronous rotation speed of the automatic transmission and the change amount (increase amount) of the input shaft rotation speed of the automatic transmission. ) To control the hydraulic pressure. For example, when the difference between the input shaft rotational speed and the synchronous rotational speed is large, the hydraulic pressure is controlled to increase more than when the difference is small. As a result, when it is necessary to increase the input shaft rotation speed more greatly in order to proceed with the shift, the input shaft rotation speed can be quickly increased by increasing the engagement force of the friction engagement element. Further, for example, when the amount of change in the input shaft rotation speed of the automatic transmission is large, the amount of increase in hydraulic pressure is controlled to be smaller than when it is small. As a result, if the amount of change in the input shaft rotation speed is large, and it can be said that the shift will proceed without increasing the engagement force of the friction engagement element, the increase amount of the engagement force is reduced to reduce the friction engagement element. The shock generated by the engagement can be reduced.

  According to an eighth aspect of the present invention, there is provided a control apparatus for a vehicle according to a difference between an input shaft rotational speed and a synchronous rotational speed of an automatic transmission and a change amount of the input shaft rotational speed of the automatic transmission. Before controlling the hydraulic pressure, the friction engagement element is maintained at a pressure at which the engagement force is not generated for the first time, and then increased to a pressure at which the friction engagement element generates the engagement force, and is maintained for the second time. And further includes means for controlling the hydraulic pressure.

  According to the eighth aspect of the invention, the frictional engagement element is applied before the hydraulic pressure is controlled in accordance with the difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission and the change amount of the input shaft rotational speed of the automatic transmission. The hydraulic pressure is controlled such that the pressure is maintained at a pressure that does not generate a resultant force for a first time, then increases to a pressure at which the frictional engagement element generates an engaging force, and is maintained for a second time. Thereby, the change of the oil pressure when the friction engagement element generates the engagement force can be suppressed. Therefore, the engagement force of the friction engagement element can be stabilized. As a result, it is possible to reduce a shock that occurs when the frictional engagement element is engaged.

  In the vehicle control apparatus according to the ninth invention, in addition to the configuration of the seventh or eighth invention, the control means includes a difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission and the input of the automatic transmission. Means for controlling the hydraulic pressure so as to become the target hydraulic pressure when the hydraulic pressure after the control according to the change amount of the shaft rotational speed is lower than the target hydraulic pressure is included.

  According to the ninth aspect, when the hydraulic pressure after the control according to the difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission and the change amount of the input shaft rotational speed of the automatic transmission is lower than the target hydraulic pressure. Then, the hydraulic pressure is controlled so as to reach the target hydraulic pressure. That is, if the hydraulic pressure after control according to the difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission and the amount of change in the input shaft rotational speed of the automatic transmission is higher than the target hydraulic pressure, the target hydraulic pressure is set. Hydraulic pressure control is not performed. Thereby, it is possible to suppress unnecessary control of the hydraulic pressure.

  According to a tenth aspect of the present invention, in addition to the configuration of any one of the first to ninth aspects, the vehicle control apparatus is configured to rotate synchronously with the input shaft rotational speed of the automatic transmission after the hydraulic pressure is controlled to become the target hydraulic pressure. Means are further included for controlling the hydraulic pressure to gradually increase with a slope depending on a value related to the difference from the number.

  According to the tenth invention, after the hydraulic pressure is controlled so as to become the target hydraulic pressure, the hydraulic pressure is controlled so as to gradually increase with a gradient corresponding to the value relating to the difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission. The For example, the hydraulic pressure is controlled so as to gradually increase with a gradient corresponding to the difference between the difference between the input shaft rotation speed and the synchronous rotation speed of the automatic transmission and the difference between the input shaft rotation speed and the synchronous rotation speed of the automatic transmission. . As a result, in the state where the difference between the input shaft rotation speed and the synchronous rotation speed of the automatic transmission is small, the friction engagement element is gently engaged or synchronized with the input shaft rotation speed of the automatic transmission. In a state where it can be said that the difference from the rotational speed is large, the friction engagement element can be quickly engaged. Therefore, the friction engagement element can be engaged in a manner corresponding to the progress state of the shift.

  According to an eleventh aspect of the present invention, there is provided a vehicle control device that automatically connects a power source and a plurality of gear stages having different gear ratios by selectively engaging a plurality of friction engagement elements. A control device for a vehicle including a transmission. This control device includes a setting means for setting a target hydraulic pressure in accordance with an input torque of the automatic transmission, a difference between an input shaft rotational speed and a synchronous rotational speed of the automatic transmission, and automatic transmission during downshifting. If the time until synchronization, which is predicted by the rate of change of the difference between the input shaft rotation speed and the synchronous rotation speed of the machine, is smaller than a predetermined value, it will be released from the released state at the time of shift down so that the target oil pressure is reached. Control means for controlling the hydraulic pressure supplied to the frictional engagement element to be engaged.

  According to the first invention, the target oil pressure is set according to the input torque of the automatic transmission. During downshifting, the time until synchronization is predicted by the change rate of the difference between the input shaft speed and the synchronous speed of the automatic transmission and the difference between the input shaft speed and the synchronous speed of the automatic transmission. When it is smaller than a predetermined value, the hydraulic pressure supplied to the frictional engagement element that is brought into the engaged state from the released state at the time of downshifting is controlled so that the target hydraulic pressure is reached. Thereby, the engagement force of the friction engagement element can be set to a value corresponding to the input torque of the automatic transmission. Therefore, it can suppress that engagement force becomes low with respect to the input torque of an automatic transmission, or becomes high. As a result, it is possible to provide a vehicle control device that can suppress the engine speed increase and shock during a shift.

  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 FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a torque converter 2100, a planetary gear unit 3000 that forms part of the automatic transmission 2000, a hydraulic circuit 4000 that forms part of the automatic transmission 2000, a propeller shaft 5000, A differential gear 6000, a rear wheel 7000, and an ECU (Electronic Control Unit) 8000 are included. The control device according to the present embodiment is realized by executing a program recorded in a ROM (Read Only Memory) 8002 of ECU 8000, for example.

  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. The auxiliary power 1004 such as an alternator and an air conditioner is driven by the driving force of the engine 1000. A motor may be used as a power source instead of or in addition to engine 1000.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 2100. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The driving force output from automatic transmission 2000 is transmitted to left and right rear wheels 7000 via propeller shaft 5000 and differential gear 6000.

  The ECU 8000 includes a position switch 8006 for the shift lever 8004, an accelerator opening sensor 8010 for the accelerator pedal 8008, a pedaling force sensor 8014 for the brake pedal 8012, a throttle opening sensor 8018 for the electronic throttle valve 8016, and an engine speed sensor 8020. The input shaft rotational speed sensor 8022, the output shaft rotational speed sensor 8024, the oil temperature sensor 8026, and the water temperature sensor 8028 are connected via a harness or the like.

  The position (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. The pedaling force sensor 8014 detects the pedaling force of the brake pedal 8012 (the force with which the driver steps on the brake pedal 8012), and transmits a signal representing the detection result to the 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 representing the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Instead of or in addition to the electronic throttle valve 8016, the amount of air drawn into the engine 1000 can be reduced by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  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 (turbine rotational speed NT of torque converter 2100), 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.

  Oil temperature sensor 8026 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 2000, and transmits a signal indicating the detection result to ECU 8000.

  Water temperature sensor 8028 detects the temperature (water temperature) of cooling water for engine 1000 and transmits a signal representing the detection result to ECU 8000.

  The ECU 8000 includes a position switch 8006, an accelerator opening sensor 8010, a pedal effort sensor 8014, a throttle opening sensor 8018, an engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, an oil temperature sensor 8026, and a water temperature sensor. Based on a signal sent from 8028 or the like, a map stored in the ROM 8002, and a program, the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000 has the forward 1st to 8th gears when the shift lever 8004 is in the D (drive) position and the D (drive) range is selected as the shift range of automatic transmission 2000. Automatic transmission 2000 is controlled so that one of these gears is formed. The automatic transmission 2000 can transmit a driving force to the rear wheel 7000 by forming any one of the first to eighth forward gears. In the D range, it may be possible to form a higher gear than the eighth gear. The gear stage to be formed is determined based on a shift diagram created in advance by experiments or the like using the vehicle speed and the accelerator opening as parameters.

  As shown in FIG. 1, ECU 8000 includes an engine ECU 8100 that controls engine 1000 and an ECT (Electronic Controlled Transmission) _ECU 8200 that controls automatic transmission 2000.

  Engine ECU 8100 and ECT_ECU 8200 are configured to be able to transmit and receive signals to and from each other. In the present embodiment, engine ECU 8100 transmits to ECT_ECU 8200 a signal representing the accelerator opening and the target idle speed of engine 1000. ECT_ECU 8200 transmits to engine ECU 8100 a signal representing a torque request amount determined as torque to be output by engine 1000.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 2100 having an input shaft 2102 coupled to the crankshaft.

  The planetary gear unit 3000 includes a front planetary 3100, a rear planetary 3200, a C1 clutch 3301, a C2 clutch 3302, a C3 clutch 3303, a C4 clutch 3304, a B1 brake 3311, a B2 brake 3312, and a one-way clutch (F). 3320.

  The front planetary 3100 is a double pinion type planetary gear mechanism. Front planetary 3100 includes a first sun gear (S1) 3102, a pair of first pinion gears (P1) 3104, a carrier (CA) 3106, and a ring gear (R) 3108.

  The first pinion gear (P1) 3104 meshes with the first sun gear (S1) 3102 and the first ring gear (R) 3108. The first carrier (CA) 3106 supports the first pinion gear (P1) 3104 so that it can revolve and rotate.

  First sun gear (S1) 3102 is fixed to gear case 3400 so as not to rotate. First carrier (CA) 3106 is coupled to input shaft 3002 of planetary gear unit 3000.

  The rear planetary 3200 is a Ravigneaux type planetary gear mechanism. The rear planetary 3200 includes a second sun gear (S2) 3202, a second pinion gear (P2) 3204, a rear carrier (RCA) 3206, a rear ring gear (RR) 3208, a third sun gear (S3) 3210, a third Pinion gear (P3) 3212.

  Second pinion gear (P2) 3204 meshes with second sun gear (S2) 3202, rear ring gear (RR) 3208, and third pinion gear (P3) 3212. Third pinion gear (P3) 3212 meshes with third sun gear (S3) 3210 in addition to second pinion gear (P2) 3204.

  The rear carrier (RCA) 3206 supports the second pinion gear (P2) 3204 and the third pinion gear (P3) 3212 so that they can revolve and rotate. Rear carrier (RCA) 3206 is coupled to one-way clutch (F) 3320. The rear carrier (RCA) 3206 becomes non-rotatable when the first gear is driven. Rear ring gear (RR) 3208 is coupled to output shaft 3004 of planetary gear unit 3000.

  The one-way clutch (F) 3320 is provided in parallel with the B2 brake 3312. That is, the outer race of the one-way clutch (F) 3320 is fixed to the gear case 3400, and the inner race is connected to the rear carrier (RCA) 3206.

  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 the brakes and the clutches in the combinations shown in the operation table, a forward 1st to 8th gear and a reverse 1st and 2nd gear are formed.

  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”). SL2 (described as SL (4)) 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SL5 linear solenoid (hereinafter referred to as SL (3)). , SL (5)) 4250, SLT linear solenoid (hereinafter referred to as SLT) 4300, and 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 path 4102 is finally supplied to the C1 clutch 3301, the C2 clutch 3302, and the C3 clutch 3303. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3312.

  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 3301. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3302. SL (3) 4230 regulates the hydraulic pressure supplied to the C3 clutch 3303. SL (4) 4240 regulates the hydraulic pressure supplied to C4 clutch 3304. SL (5) 4250 regulates the hydraulic pressure supplied to the B1 brake 3311.

  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, SL (4) 4250, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3312. 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 SLU solenoid valve (not shown) and the biasing force of the spring.

  When 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 3312 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 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 3312.

  The ECU 8000 will be further described with reference to FIG. The functions of ECU 8000 described below may be realized by hardware or may be realized by software.

  Engine ECU 8100 of ECU 8000 includes a torque control unit 8110, a target idle speed setting unit 8120, and an idle control unit 8130.

  The torque control unit 8110 receives the torque request amount output from the ECT_ECU 8200, and the throttle opening of the electronic throttle valve 8016 and the ignition timing by the ignition plug so that the torque corresponding to the torque request amount is output from the engine 1000. To control.

  The target idle speed setting unit 8120 is a target that is a target value of the engine speed NE when the vehicle is at a standstill and when the vehicle is idling (when the accelerator opening is “0”) based on the water temperature and the load of the auxiliary machine 1004. Set the idle speed. As for the method for setting the target idle speed, a known general technique may be used, and therefore, detailed description thereof will not be repeated here.

  The idle control unit 8130 controls the throttle opening of the electronic throttle valve 8016, the ignition timing by the ignition plug, and the like so that the engine speed NE becomes the target idle speed when the accelerator opening is “0”. To do.

  ECT_ECU 8200 of ECU 8000 includes a vehicle speed detection unit 8210, a shift determination unit 8220, a shift control unit 8230, an up amount setting unit 8250, and a torque request unit 8260.

  The vehicle speed detector 8210 calculates (detects) the vehicle speed from the output shaft rotational speed NO of the automatic transmission 2000.

  Shift determination unit 8220 includes a first determination unit 8221 and a second determination unit 8222. As shown in FIG. 6, first determination unit 8221 determines whether to perform a gear stage to be formed, that is, whether to perform an upshift or a downshift, according to a shift diagram with vehicle speed and accelerator opening as parameters. . In other words, first determination unit 8221 determines the vehicle speed and accelerator opening at which upshift or downshift is performed. In the shift diagram, an upshift line and a downshift line are set for each type of shift (combination of the gear stage before the shift and the gear stage after the shift).

  Second determination unit 8222 determines whether or not to downshift based on the vehicle speed during coasting (running state when engine 1000 is in an idle state). That is, the second determination unit 8222 determines the vehicle speed at which the downshift occurs during the coasting.

  Hereinafter, downshifting during coasting is also referred to as coasting down. The vehicle speed to coast down is determined for each type of shift. As shown in FIG. 6, the coasting vehicle speed is set to a vehicle speed that is higher than the vehicle speed determined when the accelerator opening is “0” from the upshift line in the shift diagram.

  For example, when the accelerator opening is “0”, the vehicle speed at which coast down is performed from the third gear to the second gear rather than the vehicle speed determined by the upshift line from the second gear to the third gear. Is determined to be high.

  Shift control unit 8230 controls the hydraulic pressure supplied to the clutch and brake (friction engagement element) of planetary gear unit 3000 so as to perform upshift or downshift when it is determined that upshift or downshift is to be performed. .

  Shift control unit 8230 includes a first fill unit 3232, a first control unit 8241, a second control unit 8242, a third control unit 8243, and a fourth control unit 8244.

  The first fill unit 3232 and the first control unit 8241 to the fourth control unit 8244 control the hydraulic pressure supplied to the friction engagement element that is brought into the engaged state from the released state at the time of downshift (including the time of coast down). To do.

  When it is determined that a downshift is to be performed, first fill section 3232 increases stepwise to a predetermined pressure P (1) at time T (1) as shown in FIG. At a time T (2) after the predetermined time has elapsed, the hydraulic pressure is controlled so as to decrease stepwise to a pressure P (2) that is predetermined to a value that does not generate the engagement force of the friction engagement element. By the hydraulic control by the first fill portion 3232, ATF is filled in the hydraulic cylinder of the friction engagement element.

  As shown in FIG. 7, the first control unit 8241 maintains the pressure P (2) for a first predetermined time, and at time T (3), the friction engagement element generates an engagement force. Is slightly increased by a predetermined step-up amount ΔP (1), and the hydraulic pressure is controlled so as to be maintained for a predetermined second time.

  As shown in FIG. 7, the second control unit 8242 controls the hydraulic pressure so as to gradually increase at a sweep up amount (gradient) set by a first sweep up amount setting unit 8252 described later at time T (4). . As will be described later, the sweep-up amount may be set to “0”. That is, the hydraulic pressure may not increase gradually. Hereinafter, the increase amount of the hydraulic pressure gradually increased by the second control unit 8242 is also referred to as ΔP (2).

  As shown in FIG. 7, the third control unit 8243 sets the pressure P (2) to be described later at time T (5) when the difference between the turbine rotational speed NT and the synchronous rotational speed becomes smaller than a predetermined value. The hydraulic pressure is controlled so as to increase stepwise to the target hydraulic pressure to which the step-up amount (increase amount) ΔP (3) set by the step-up amount setting unit 8253 to be added is maintained for a predetermined time.

  Here, the synchronous rotational speed is a value calculated from the product of the gear ratio of the gear stage after completion of the downshift and the output shaft rotational speed NO of automatic transmission 2000. As shown in FIG. 7, the step-up amount ΔP (3) is set as an increase amount of the hydraulic pressure from the pressure P (2).

  The third control unit 8243 uses the step-up amount setting unit 8253 to set the hydraulic pressure step-up amount ΔP (1) by the first control unit 8241 and the sum of the hydraulic pressure increase amount ΔP (2) by the second control unit 8242. When the set step-up amount ΔP (3) is large, the hydraulic pressure is controlled so as to increase stepwise.

  As shown in FIG. 7, the fourth control unit 8244 controls the hydraulic pressure so as to gradually increase at a sweep up amount (gradient) set by a second sweep up amount setting unit 8254 described later at time T (6). .

  The up amount setting unit 8250 includes a first sweep up amount setting unit 8252, a step up amount setting unit 8253, and a second sweep up amount setting unit 8254.

  As shown in FIG. 8, the first sweep-up amount setting unit 8252 has a difference between the synchronous rotational speed and the turbine rotational speed NT (input shaft rotational speed NI) (synchronous rotational speed−turbine rotational speed NT) and a predetermined value. The sweep-up amount is set using the change amount dNT of the turbine rotational speed NT per time as a parameter.

  When the difference between the synchronous rotation speed and the turbine rotation speed NT is large, the sweep-up amount is set to be larger than when the difference is small. When the change amount dNT of the turbine rotational speed NT is small, the sweep-up amount is set to be larger than when it is large. When the change amount dNT of the turbine rotational speed NT is larger than dNT (0), the sweep-up amount is set to “0”. This is because if the hydraulic pressure is increased in a state where the turbine rotational speed NT is changing rapidly, the shock associated with the engagement of the friction engagement elements increases.

  The step-up amount setting unit 8253 sets the step-up amount ΔP (3) as the sum of the basic amount according to the input torque of the automatic transmission 2000 and the correction amount according to the deceleration of the vehicle, and the pressure P ( The pressure obtained by adding the step-up amount ΔP (3) to 2) is set as the target hydraulic pressure. The basic amount corresponding to the input torque is set because a larger engagement force is required as the input torque increases.

  The correction amount corresponding to the deceleration is set because the reaction force received when the frictional engagement element is engaged increases as the vehicle speed, that is, the output shaft rotational speed NO decreases, and a larger engagement force is required. Because it becomes.

  As shown in FIG. 9, step-up amount setting unit 8253 sets a basic amount of step-up amount using target idle speed and output shaft speed NO of automatic transmission 2000 as parameters.

  The target idle speed is a parameter representing the output shaft speed of the engine 1000, that is, the output torque. When the target idle speed is high, it can be said that the input torque of automatic transmission 2000 is larger than when the target idle speed is low. Accordingly, the basic amount of the step-up amount is set so that when the target idle speed is high, it is larger than when it is low.

  The output shaft rotational speed NO is a parameter representing the synchronous rotational speed, that is, the future turbine rotational speed NT. When the output shaft rotational speed NO is high, it can be said that the input torque of the automatic transmission 2000 is smaller than when the output shaft rotational speed NO is low. That is, when the turbine speed NT is high, it can be said that the torque amplifying effect in the torque converter 2100 is small and the input torque of the automatic transmission 2000 is small compared to when the turbine speed NT is low. Therefore, the step-up amount is set to be smaller when the output shaft rotational speed NO is high than when it is low.

  As shown in FIG. 10, the step-up amount setting unit 8253 sets a correction amount for the step-up amount using the change amount (decrease amount) dNO of the output shaft rotational speed NO as a parameter. In the present embodiment, the correction amount is a positive value.

  When the change amount dNO of the output shaft rotational speed NO is large, it can be said that the deceleration of the vehicle is larger than when the change amount dNO is small. That is, it can be said that when the change amount dNO of the output shaft rotational speed NO is large, the reaction force that the friction engagement element receives during engagement is larger than when the change amount dNO is small. Therefore, the correction amount of the step-up amount is set so that the change amount dNO of the output shaft rotational speed NO is larger when compared with the small change amount dNO.

  As shown in FIG. 11, the second sweep-up amount setting unit 8254 has a difference (synchronous rotational speed−turbine rotational speed) between the synchronous rotational speed and the turbine rotational speed NT (input shaft rotational speed NI), and the synchronous rotational speed and the turbine. The sweep-up amount is set with the change amount of the difference from the rotational speed NT as a parameter.

  In a state where the difference between the synchronous rotational speed and the turbine rotational speed NT is small, when the change amount of the difference between the synchronous rotational speed and the turbine rotational speed NT is small (when negative), it is larger than when it is “0”. The sweep-up amount is set so that In a state where the difference between the synchronous rotational speed and the turbine rotational speed NT is small, the change amount of the difference between the synchronous rotational speed and the turbine rotational speed NT is small, that is, when the turbine rotational speed NT is approaching the synchronous rotational speed. However, the shock that can be generated when the friction engagement element is engaged is small.

  In a state where the difference between the synchronous rotational speed and the turbine rotational speed NT is small, when the amount of change in the difference between the synchronous rotational speed and the turbine rotational speed NT is large (when positive), it is larger than when it is “0”. The sweep-up amount is set so that This is because the difference between the synchronous rotational speed and the turbine rotational speed NT is widened, and it is considered that the engagement force of the friction engagement element is insufficient.

  In a state where the difference between the synchronous rotational speed and the turbine rotational speed NT is large, the sweep-up amount is set to be larger when the change amount of the difference between the synchronous rotational speed and the turbine rotational speed NT is large than when it is small. .

  This is because it is necessary to quickly engage the friction engagement element in a state where the difference between the synchronous rotational speed and the turbine rotational speed NT is large and the difference between the synchronous rotational speed and the turbine rotational speed NT is widened.

  Torque requesting unit 8260 sets a torque request amount that is a torque required for engine 1000 based on the accelerator opening and the like.

  A control structure of a program executed by ECU 8000 serving as the control device according to the present embodiment will be described with reference to FIGS. Note that the program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter step is abbreviated as S) 100, ECU 8000 determines whether or not to downshift. If it is determined that a downshift is to be performed (YES in S100), the process proceeds to S110. Otherwise (NO in S100), this process ends.

  In S110, ECU 8000 controls the hydraulic pressure so as to increase stepwise to pressure P (1) and then decrease stepwise to pressure P (2) after a predetermined time has elapsed.

  In S120, ECU 8000 maintains the pressure P (2) for a predetermined first time, and then increases the step-up amount ΔP (1) and controls the hydraulic pressure so as to maintain it for the second time. To do.

  In S130, ECU 8000 uses the difference (synchronous rotational speed−turbine rotational speed NT) between synchronous rotational speed and turbine rotational speed NT (input shaft rotational speed NI) and change amount dNT of turbine rotational speed NT as parameters for the sweep-up amount. Set. In S132, ECU 8000 controls the hydraulic pressure so as to gradually increase with the set sweep-up amount (gradient).

  In S140, ECU 8000 determines whether or not the difference between turbine rotational speed NT and synchronous rotational speed is smaller than a predetermined value, or whether synchronous prediction time TSNC is smaller than a predetermined value. .

  The predicted synchronization time TSNC is calculated by dividing the difference NTS4X between the turbine rotational speed NT and the synchronous rotational speed by the change amount dNTS4X of the difference NTS4X. That is, the synchronization prediction time TSNC = NTS4X / dNTS4X.

  If the difference between turbine rotational speed NT and synchronous rotational speed is smaller than a predetermined value (YES in S140), the process proceeds to S150. If synchronization predicted time TSNC is smaller than a predetermined value (YES in S140), the process proceeds to S150. If not (NO in S140), the process returns to S140.

  In S150, ECU 8000 sets step-up amount ΔP (3) using target idle speed, output shaft speed NO of automatic transmission 2000, and change amount (decrease amount) dNO of output shaft speed NO as parameters.

  In S152, ECU 8000 determines whether or not step-up amount ΔP (3) is greater than the sum of step-up amount ΔP (1) and gradually increased hydraulic pressure increase amount ΔP (2). If step-up amount ΔP (3) is larger than the sum of step-up amount ΔP (1) and gradually increased hydraulic pressure increase amount ΔP (2) (YES in S152), the process proceeds to S154. If not (NO in S152), the process proceeds to S160.

  In S154, ECU 8000 increases the pressure to a target hydraulic pressure obtained by adding step-up amount ΔP (3) to pressure P (2) in S110, and controls the hydraulic pressure so as to maintain it for a predetermined time.

  In S160, ECU 8000 sets the sweep-up amount using as parameters the difference between synchronous rotational speed and turbine rotational speed NT (synchronous rotational speed−turbine rotational speed) and the amount of change in the difference between synchronous rotational speed and turbine rotational speed NT. To do. In S162, ECU 8000 controls the hydraulic pressure so as to gradually increase with the set sweep-up amount.

  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.

  If it is determined that a downshift is to be performed (YES in S100), as shown in FIG. 14, in order to fill the hydraulic pressure in the hydraulic servo cylinder of the friction engagement element at time T (7), pressure P ( The hydraulic pressure is controlled so as to increase stepwise to 1) and then decrease stepwise to pressure P (2) at time T (8) after a predetermined time has elapsed (S110).

  At time T (9) after maintaining the pressure P (2) for a predetermined first time, the hydraulic pressure is controlled so as to increase by the step-up amount ΔP (1) and maintain for the second time. (S120).

  Thereby, as shown in FIG. 14, the change of the hydraulic pressure actually supplied to the friction engagement element after time T (9) can be reduced. Therefore, the engagement force at the initial stage of engagement of the friction engagement element can be stabilized.

  Thereafter, the sweep-up amount is set using the difference (synchronous rotational speed−turbine rotational speed NT) between the synchronous rotational speed and the turbine rotational speed NT (input shaft rotational speed NI) and the change amount dNT of the turbine rotational speed NT as parameters ( S130). As shown in FIG. 15, at time T (10), the hydraulic pressure is controlled so as to gradually increase with the set sweep-up amount (gradient) (S132).

  When the difference between turbine rotational speed NT and synchronous rotational speed is smaller than a predetermined value at time T (11) in FIG. 15 (YES in S140), or synchronous predicted time TSNC is a predetermined value. (YES in S140), the step-up amount is set using the target idle speed, output shaft speed NO of automatic transmission 2000, and change amount dNO of output shaft speed NO as parameters (S150).

  Here, as shown in FIG. 15, when the engine speed NE is low, the turbine speed NT is low. Therefore, the difference between the synchronous rotational speed and the turbine rotational speed NT is increased. In this state, the sweep-up amount is set large.

  In this case, the step-up amount ΔP (3) can be smaller than the sum of the step-up amount ΔP (1) and the gradually increased hydraulic pressure increase amount ΔP (2). If step-up amount ΔP (3) is smaller than the sum of step-up amount ΔP (1) and gradually increased oil pressure increase amount ΔP (2) (NO in S152), it is necessary to increase the oil pressure further. Absent.

  Accordingly, without increasing the hydraulic pressure stepwise, at time T (12), the difference between the synchronous rotational speed and the turbine rotational speed NT (synchronous rotational speed−turbine rotational speed), and the synchronous rotational speed and the turbine rotational speed NT. The sweep-up amount is set using the change amount of the difference as a parameter (S160). The hydraulic pressure is controlled so as to gradually increase with the sweep-up amount (S162).

  On the other hand, when the engine speed NE is high, the turbine speed NT is high. Therefore, the difference between the synchronous rotation speed and the turbine rotation speed NT is reduced. In this state, the sweep-up amount is set small. If the change amount dNT of the turbine rotational speed NT is larger than dNT (0), the step-up amount is set to “0” as shown in FIG.

  In these cases, the step-up amount ΔP (3) can be larger than the sum of the step-up amount ΔP (1) and the gradually increased hydraulic pressure increase amount ΔP (2). As shown in FIG. 16, when step-up amount ΔP (3) is larger than the sum of step-up amount ΔP (1) and gradually increased hydraulic pressure increase amount ΔP (2) (YES in S152), pressure The hydraulic pressure is controlled so as to increase stepwise to the target hydraulic pressure obtained by adding the step-up amount ΔP (3) to P (2) and to maintain for a predetermined time (S154).

  Thereafter, at time T (12), the amount of sweep-up is set using the difference between the synchronous rotational speed and the turbine rotational speed NT (synchronous rotational speed−turbine rotational speed) and the amount of change in the difference between the synchronous rotational speed and the turbine rotational speed NT as parameters. Is set (S160). The hydraulic pressure is controlled so as to gradually increase with the sweep-up amount (S162).

  As described above, according to the ECU that is the control device according to the present embodiment, the step-up amount according to the input torque of automatic transmission 2000 using the target idle speed and the output shaft speed NO of automatic transmission 2000. ΔP (3) is set. In a state where the difference between the turbine rotational speed NT and the synchronous rotational speed is smaller than a predetermined value, or in a state where the synchronous prediction time TSNC is smaller than a predetermined value, the step-up amount is increased to the pressure P (2). (Increase amount) The oil pressure is controlled to increase stepwise up to the target oil pressure to which ΔP (3) is added. Thereby, the engagement force of the friction engagement element can be set to a value corresponding to the input torque of the automatic transmission. Therefore, it can suppress that engagement force becomes low with respect to the input torque of an automatic transmission, or becomes high. As a result, engine speed increase and shock during shifting can be suppressed.

  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 of a vehicle. It is a skeleton figure which shows the planetary gear unit of an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the hydraulic circuit of an automatic transmission. It is a functional block diagram of ECU. It is a figure which shows a shift map. It is a timing chart (the 1) which shows the oil pressure directions value at the time of a downshift. It is a figure (the 1) which shows the map which defined sweep-up amount. It is a figure which shows the map which defined the basic amount of step-up amount (DELTA) P (3). It is a figure which shows the map which defined the correction amount of step-up amount (DELTA) P (3). It is a figure (the 2) which shows the map which defined sweep-up amount. It is FIG. (1) which shows the control structure of the program which ECU performs. It is FIG. (2) which shows the control structure of the program which ECU performs. It is a timing chart (the 2) which shows the oil pressure directions value at the time of a downshift. It is a timing chart (the 3) which shows the oil pressure directions value at the time of a downshift. It is a timing chart (the 4) which shows the oil pressure directions value at the time of a downshift.

Explanation of symbols

  1000 engine, 2000 automatic transmission, 2100 torque converter, 3000 planetary gear unit, 4000 hydraulic circuit, 8000 ECU, 8002 ROM, 8004 shift lever, 8006 position switch, 8008 accelerator pedal, 8010 accelerator opening sensor, 8012 brake pedal, 8014 pedal force sensor 8016 electronic throttle valve, 8018 throttle opening sensor, 8020 engine speed sensor, 8022 input shaft speed sensor, 8024 output shaft speed sensor, 8026 oil temperature sensor, 8028 water temperature sensor, 8100 engine ECU, 8110 torque control unit, 8120 Target idle speed setting unit, 8200 ECT_ECU, 8210 vehicle speed detection unit, 8220 Shift determination unit, 8221 first determination unit, 8222 second determination unit, 8230 shift control unit, 3231 first fill unit, 8241 first control unit, 8242 second control unit, 8243 third control unit, 8244 fourth control unit, 8250 Up amount setting unit, 8252 First sweep up amount setting unit, 8253 Step up amount setting unit, 8254 Second sweep up amount setting unit, 8260 Torque request unit.

Claims (10)

A vehicle control device comprising: a power source; and an automatic transmission that is coupled to the power source and selectively engages a plurality of friction engagement elements to establish a plurality of gear stages having different gear ratios. There,
Setting means for stepwise setting a target hydraulic pressure according to the input torque of the automatic transmission;
During the downshift, when the difference between the input shaft rotational speed and the synchronous rotational speed of the automatic transmission is smaller than a predetermined value, the engine is released from the released state at the time of downshifting so that the target hydraulic pressure is obtained. Control means for controlling the hydraulic pressure supplied to the friction engagement element to be engaged ;
Before the hydraulic pressure is controlled to reach the target hydraulic pressure, the frictional engagement element increases stepwise to a pressure that generates an engagement force, and then the input shaft rotational speed and the synchronous rotational speed of the automatic transmission are increased. And a means for controlling the hydraulic pressure in accordance with the difference between the two and the amount of change in the input shaft rotational speed of the automatic transmission .   The vehicle control device according to claim 1, wherein the setting means includes means for setting the target hydraulic pressure based on an output shaft rotational speed of the automatic transmission.   The vehicle control device according to claim 2, wherein the setting means includes means for setting the target hydraulic pressure so that the output hydraulic pressure of the automatic transmission is smaller when the output shaft rotational speed is high than when it is low. The control device further includes means for controlling the output shaft rotational speed of the power source to be a target idle rotational speed when the vehicle is stopped and the power source is idle.
The vehicle control device according to any one of claims 1 to 3, wherein the setting means includes means for setting the target oil pressure so that the target idle speed is higher when the target idle speed is high than when the target idle speed is low. .   The vehicle control device according to any one of claims 1 to 4, wherein the control device further includes correction means for correcting the target hydraulic pressure in accordance with a deceleration of the vehicle.   6. The vehicle control device according to claim 5, wherein the correction means includes means for correcting the target hydraulic pressure to be larger when the deceleration of the vehicle is large than when the deceleration is small. The control device includes the friction engagement before controlling the hydraulic pressure in accordance with a difference between the input shaft rotation speed of the automatic transmission and the synchronous rotation speed and a change amount of the input shaft rotation speed of the automatic transmission. The hydraulic pressure is such that the pressure is maintained at a pressure at which the element does not generate an engagement force for a first time , and then increases stepwise to a pressure at which the friction engagement element generates an engagement force, and is maintained for a second time. further comprising means for controlling the control apparatus for a vehicle according to claim 1. The control means has a hydraulic pressure lower than the target hydraulic pressure after being controlled according to a difference between the input shaft rotational speed of the automatic transmission and the synchronous rotational speed and a change amount of the input shaft rotational speed of the automatic transmission. The vehicle control device according to claim 7, further comprising means for controlling the hydraulic pressure so that the target hydraulic pressure is reached. After the hydraulic pressure is controlled so as to become the target hydraulic pressure, the control device gradually increases the hydraulic pressure with a gradient according to a value related to a difference between the input shaft rotational speed of the automatic transmission and the synchronous rotational speed. further comprising means for controlling a control apparatus for a vehicle according to any one of claims 1-8. A vehicle control device comprising: a power source; and an automatic transmission that is coupled to the power source and selectively engages a plurality of friction engagement elements to establish a plurality of gear stages having different gear ratios. There,
Setting means for stepwise setting a target hydraulic pressure according to the input torque of the automatic transmission;
During the downshift, the time until the synchronization predicted by the difference between the difference between the input shaft speed and the synchronous speed of the automatic transmission and the difference between the input shaft speed and the synchronous speed of the automatic transmission is reached. Control means for controlling the hydraulic pressure supplied to the frictional engagement element that is brought into the engaged state from the released state at the time of the shift down so that the target hydraulic pressure is reached when the time is smaller than a predetermined value and,
Before the hydraulic pressure is controlled to reach the target hydraulic pressure, the frictional engagement element increases stepwise to a pressure that generates an engagement force, and then the input shaft rotational speed and the synchronous rotational speed of the automatic transmission are increased. And a means for controlling the hydraulic pressure in accordance with the difference between the two and the amount of change in the input shaft rotational speed of the automatic transmission .

Images