JP2010164084A - Speed-change controller of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed-change controller of automatic transmission which can improve drivability when speed is changed by accurately studying an engaging-side hydraulic pressure. <P>SOLUTION: The speed-change controller of automatic transmission as follows: a transmission ECU increases an engine torque and obtains a turbine rotation number NT (A) when a downshift instruction is obtained (step S12); a turbine rotation number NT (B) is obtained (step S14), and a variation gradient of the turbine rotation number is calculated as a real ΔNT (step S15) after a measuring time T passes; a target ▵NT is calculated based on a vehicle speed and an engine torque Te (step S16); and the transmission ECU sets a value obtained by subtracting a compensating hydraulic pressure ▵P' from this engaging-side hydraulic pressure P as a next engaging-side hydraulic pressure (step S18) when the real ▵NT is the target ▵NT or more, and sets a value obtained by adding a compensating hydraulic pressure ▵P to this engaging-side hydraulic pressure P as a next engaging-side hydraulic pressure (step S19) when the real ▵NT is less than the target ▵NT. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control device for an automatic transmission that executes torque-up of a power source during a downshift.

  2. Description of the Related Art Conventionally, in a shift control device for an automatic transmission having a plurality of friction engagement devices, when performing shift control by releasing and engaging the friction engagement device, the release side that is supplied to the release friction engagement device The hydraulic pressure and the engagement-side hydraulic pressure supplied to the engagement-side friction engagement device are optimized to improve the drivability of the vehicle at the time of shifting.

  As a shift control device for this type of automatic transmission, there is known a device for instructing a power source to increase torque in a shift control at the time of downshift to shorten a time required for the downshift (for example, a patent Reference 1).

  In this conventional shift control device described in Patent Document 1, when a downshift instruction is input from the shift lever, the release side hydraulic pressure starts to decrease, and the power source is instructed to increase torque, and the torque converter By increasing the input shaft rotational speed of the automatic transmission connected to the output shaft of the power source through the input shaft, the input shaft rotational speed is brought close to the synchronous rotational speed at the end of the shift, and the shift time is shortened. Yes.

  Further, when executing torque increase, by stopping the generation of power by some of the cylinders constituting the internal combustion engine as a power source, the pumping loss in the internal combustion engine is reduced, thereby The increase in the output shaft rotation speed of the power source is accelerated, and the shift response is improved.

  Further, as a shift control device for this type of automatic transmission, one that changes the engagement hydraulic pressure in accordance with the progress of shift is known (for example, see Patent Document 2).

  In the conventional speed change control device described in Patent Document 2, during the power-on upshift, the release side hydraulic pressure is decreased to increase the input shaft rotational speed of the automatic transmission, and the engagement side hydraulic pressure is increased by a predetermined amount. Increasing at a rate. At this time, the engagement side hydraulic pressure is adjusted by hydraulic control according to the deviation between the target rotational speed and the actual input shaft rotational speed so that the input shaft rotational speed matches the target rotational speed. Thereby, the friction engagement device on the engagement side is smoothly engaged.

JP 2008-144738 JP-A-06-11028

  However, in the conventional transmission control device for an automatic transmission described in Patent Document 1, although the increase in the output rotational speed of the power source at the time of torque increase is accelerated, the engagement side hydraulic pressure is optimized. Was not considered. For this reason, even when the optimum value of the engagement side hydraulic pressure at the time of shifting varies due to a change in the traveling environment of the vehicle, the engagement side hydraulic pressure is not optimized and the shift characteristics vary. There was a case.

  Further, in the conventional transmission control device for an automatic transmission described in Patent Document 2, although the engagement-side hydraulic pressure is controlled according to the degree of progress of the shift control, the power source is torqued up during the shift. It was not like taking control into account. For this reason, the optimum engagement-side hydraulic pressure at the time of gear shifting varies with respect to the variation in torque output from the internal combustion engine, but the engagement side hydraulic pressure is engaged without considering the variation in torque caused by changes in the traveling environment. Since the side hydraulic pressure is set, as a result, there is a possibility that the hydraulic pressure actually supplied to the engagement-side frictional engagement device does not coincide with the optimum value for smoothly performing the shift.

  Therefore, in any case, the engagement-side hydraulic pressure is not accurately learned at the time of the shift for executing the torque increase, and as a result, the shift characteristics are varied, and the drivability is deteriorated such that the shift feeling is impaired. There was a case to do.

  The present invention has been made to solve such problems, and provides a shift control device for an automatic transmission that can improve the learning accuracy of the engagement side hydraulic pressure and improve the drivability at the time of shifting. With the goal.

  In order to achieve the above object, the shift control device for an automatic transmission according to the present invention is (1) connected to a power source via an input shaft, and a plurality of hydraulic friction engagement devices are selectively engaged. The predetermined engagement side frictional engagement device is released while the predetermined release side frictional engagement device is released among the plurality of hydraulic engagement devices with respect to the automatic transmission in which a plurality of gear stages having different gear ratios are established by In an automatic transmission shift control apparatus that executes downshift shift control for engaging the power source and torque-up the power source, instruction detection means for detecting the downshift instruction, and downshift instruction by the instruction detection means Vehicle speed detection means for detecting the vehicle speed when the vehicle is detected, and the torque increase for the power source is executed using the detection of the downshift instruction by the instruction detection means as a trigger. Torque up control means for controlling the amount of torque to be applied, and in the downshift, the engagement side hydraulic pressure supplied to the engagement side frictional engagement device is controlled in accordance with a target change speed predetermined with respect to the input shaft rotational speed. A hydraulic pressure control means for calculating, a change speed calculation means for calculating an actual change speed of the input shaft rotation speed in the downshift, and a torque amount calculation for calculating a torque amount output from the power source during execution of the torque increase Means, a target change speed setting means for setting a target change speed of the input shaft speed according to the torque amount calculated by the torque amount calculation means and the vehicle speed detected by the vehicle speed detection means, And a hydraulic pressure correction unit that learns a deviation between a change speed and the target change speed, and corrects the engagement side hydraulic pressure according to the learned deviation.

  With this configuration, even when the torque amount output from the power source is deviated from the requested torque amount due to a change in the driving environment during the torque increase in the downshift, it is actually output from the power source. The engagement-side hydraulic pressure can be learned according to the torque amount. Therefore, even when a shift in which the power source is torque-up during a downshift is executed, the learning accuracy for the engagement side hydraulic pressure can be improved and the drivability during the shift can be improved.

  Further, in the shift control device for an automatic transmission according to (1) above, (2) the torque up control means is configured to increase the torque when a predetermined time elapses after the downshift instruction is detected. A decrease in the amount of torque is started.

  With this configuration, when a predetermined time elapses from the start of the shift control, the degree of contribution that the change speed of the input shaft rotation speed is controlled by the engagement-side oil pressure increases from the contribution degree that is controlled by the torque increase. This makes it possible to execute highly accurate shift control.

  Further, in the shift control device for an automatic transmission according to (2) above, (3) the torque-up control means may increase the torque before the input shaft rotational speed reaches the synchronous rotational speed after completion of the downshift. The torque amount is reduced so as to end the process.

  With this configuration, at the time near the end of the downshift, the changing speed of the input shaft rotation speed depends only on the control on the engagement side hydraulic pressure, so that it is possible to execute highly accurate shift control by hydraulic control. It becomes possible.

  Further, in the shift control device for an automatic transmission according to (1) to (3) above, (4) the torque amount calculation means is after the torque up is started by the torque up control means, and The torque amount output from the power source is calculated before the reduction of the torque amount is started.

  With this configuration, since the torque amount at the time of torque increase that affects the actual change speed is accurately calculated, the target change speed set by the target change speed setting means includes fluctuations according to the running state of the actual torque amount. It is possible to set the target change speed in the state. Therefore, the learning of the deviation between the actual change speed and the target change speed by the hydraulic pressure correction means becomes accurate, and as a result, the learning accuracy for the engagement side hydraulic pressure can be improved and the drivability at the time of shifting can be improved.

  Even in the case of executing a shift in which the power source is torque-up during a downshift, it is possible to improve the learning accuracy for the engagement side hydraulic pressure and improve the drivability during the shift.

1 is a schematic configuration diagram illustrating a vehicle equipped with a shift control device for an automatic transmission according to an embodiment of the present invention. 1 is a skeleton diagram showing a configuration of an automatic transmission according to an embodiment of the present invention. It is an operation | movement table | surface of the automatic transmission which concerns on embodiment of this invention. 1 is a circuit diagram showing a schematic configuration of a hydraulic control circuit according to an embodiment of the present invention. It is a timing chart for demonstrating the control timing of transmission ECU which concerns on embodiment of this invention. It is a figure which shows the target (DELTA) NT setting map which concerns on embodiment of this invention. It is a flowchart for demonstrating the shift control process which concerns on embodiment of this invention.

  Hereinafter, a shift control apparatus for an automatic transmission according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

  FIG. 1 is a schematic configuration diagram showing a vehicle equipped with a shift control device for an automatic transmission according to an embodiment of the present invention. FIG. 2 is a skeleton diagram showing the configuration of the automatic transmission according to the embodiment of the present invention.

  In the present embodiment, a case will be described in which the shift control device for an automatic transmission according to the present invention is applied to an FF (Front engine Front drive) vehicle.

  As shown in FIG. 1, the vehicle 1 controls the engine 2 as a power source, a torque converter 3, a transmission mechanism 4 having a plurality of hydraulic friction engagement devices, and the torque converter 3 and the transmission mechanism 4 by hydraulic pressure. A hydraulic control circuit 9 for controlling the engine 2, an engine ECU (Electronic Control Unit) 11 for controlling the engine 2, and a transmission ECU 12 for controlling the hydraulic control circuit 9.

  The engine 2 constitutes 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 in the combustion chamber, and the crankshaft as the output shaft is rotated. An external combustion engine may be used instead of the internal combustion engine.

  The torque converter 3 increases the torque from the engine 2 to the speed change mechanism 4 to transmit the power of the engine 2 and, as will be described later, a pump impeller (hereinafter simply referred to as “impeller”) connected to the output shaft of the engine 2. An impeller), a turbine runner (hereinafter simply referred to as a turbine) connected to the input shaft of the speed change mechanism 4, and a stator that is prevented from rotating in one direction by a one-way clutch. The impeller and the turbine transmit power through a fluid.

  Further, the torque converter 3 is a lock-up clutch 47 (FIG. 2) for increasing the transmission efficiency of power from the engine 2 to the transmission mechanism 4 by mechanically directly connecting the impeller and the turbine when the vehicle 1 is traveling at high speed. See).

  The torque converter 3 and the speed change mechanism 4 constitute an automatic transmission 5. The automatic transmission 5 changes the rotational speed of a crankshaft (not shown) to a desired rotational speed by forming a desired gear stage. The power output from the output gear of the automatic transmission 5 is transmitted to left and right front wheels (not shown) via a differential gear and a drive shaft (not shown). The transmission mechanism 4 will be described in detail later.

  The hydraulic control circuit 9 has linear solenoid valves SL1 to SL5. The hydraulic control circuit 9 has an oil temperature sensor 33 for measuring the oil temperature of the hydraulic oil.

  The engine ECU 11 has a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an input / output interface (not shown). The engine ECU 11 controls the number of revolutions of the engine based on a signal input from an accelerator sensor and a throttle sensor, which will be described later, a map stored in the ROM, and the like. Further, as will be described later, based on a command from the transmission ECU 12, torque-up control of the engine 2 during downshifting, that is, blipping is executed.

  The transmission ECU 12 has a CPU, a RAM, a ROM, and an input / output interface (not shown). The ROM of the transmission ECU 12 stores a map that associates the vehicle speed and throttle opening with the gear stage of the transmission mechanism 4. Therefore, the transmission ECU 12 determines the gear stage of the speed change mechanism by the CPU based on a signal input from a vehicle speed sensor or a throttle sensor described later and a map stored in the ROM.

  The transmission ECU 12 changes the operating state of the linear solenoid valves SL1 to SL5, and selectively engages or releases the friction engagement device of the speed change mechanism 4 with an operating oil pressure using the line pressure as a source pressure. The ratio of the rotational speed between the input shaft and the output shaft of the speed change mechanism 4 is changed by a combination of engagement and release of these friction engagement devices, and a gear stage is configured. Further, as will be described later, the transmission ECU 12 learns the engagement-side hydraulic pressure supplied to the engagement-side friction engagement device at the time of downshift, and corrects the engagement-side hydraulic pressure at the next downshift. It is like that.

  As will be described later, the transmission ECU 12 includes a shift control device, instruction detection means, torque-up control means, hydraulic control means, change speed calculation means, torque amount calculation means, target change speed setting means, and hydraulic pressure correction according to the present invention. Configure the means.

  The vehicle 1 is further drawn into the engine 2 by an engine speed sensor 21 for detecting the output shaft speed NE of the engine 2, an intake air quantity sensor 22 for detecting the intake air quantity of the engine 2, and the engine 2. An intake air temperature sensor 23 for detecting the air temperature, a throttle sensor 24 for detecting the opening of the throttle valve 31, a vehicle speed sensor 25, and a cooling water temperature sensor 26 for measuring the cooling water temperature of the engine The brake sensor 27, the operation position sensor 29 for detecting the operation position of the shift lever 28, and the turbine speed sensor for detecting the turbine speed of the torque converter 3, that is, the input shaft speed NT of the automatic transmission. 30.

  The engine speed sensor 21 detects the speed of the engine 2 based on the rotation of the crankshaft.

  The throttle sensor 24 is constituted by, for example, a hall element that can obtain an output voltage corresponding to the throttle opening of the throttle valve 31. The throttle sensor 24 outputs this output voltage to the engine ECU 11 and the transmission ECU 12 as a signal representing the throttle opening of the throttle valve 31.

  The vehicle speed sensor 25 constituting the vehicle speed detecting means outputs a signal indicating the output shaft rotational speed of the speed change mechanism 4 to the engine ECU 11 and the transmission ECU 12. The engine ECU 11 and the transmission ECU 12 are configured to output the vehicle speed based on this signal. Is calculated.

  The cooling water temperature sensor 26 is composed of, for example, a thermistor whose resistance value changes according to the water temperature, and outputs a signal based on the resistance value that changes according to the cooling water temperature of the engine 2 to the engine ECU 11 and the transmission ECU 12. It has become.

  The brake sensor 27 sends a signal (stepping force switch signal) that switches from an OFF state to an ON state when a brake pedal (not shown) provided in the vehicle 1 is depressed by a driver with a predetermined depression amount to the engine ECU 11 and the transmission ECU 12. It is supposed to send.

  The operation position sensor 29 detects the position of the shift lever 28 and transmits a signal representing the detection result to the transmission ECU 12. The transmission ECU 12 forms the gear stage of the speed change mechanism 4 that is optimal from the range corresponding to the position of the shift lever 28. The operation position sensor 29 detects that the shift lever 28 is located at a manual position where the driver can select an arbitrary gear according to the operation of the driver.

  The accelerator opening sensor 32 is composed of, for example, an electronic position sensor using a hall element. When the accelerator pedal 34 mounted on the vehicle 1 is operated by the driver, the accelerator position indicated by the accelerator pedal 34 is indicated. A signal indicating the opening is output to the engine ECU 11.

  As shown in FIG. 2, the torque converter 3 is prevented from rotating in one direction by an impeller 43 connected to the output shaft 41 of the engine, a turbine 44 connected to the input shaft 48 of the transmission mechanism 4, and the one-way clutch 45. The stator 46 is provided. The impeller 43 and the turbine 44 transmit power via a fluid.

  The input shaft 48 of the transmission mechanism 4 is connected to the turbine 44 of the torque converter 3. Therefore, the input shaft 48 of the speed change mechanism 4 also functions as an output shaft of the torque converter 3. The transmission mechanism 4 includes a first set 50 of planetary gear mechanisms, a second set 60 of planetary gear mechanisms, an output gear 70, a B1 brake 72, a B2 brake 73 and a B3 brake 74 fixed to a gear case 71, and C1. The clutch 75, the C2 clutch 76, and the one-way clutch F77 are included. Here, as will be described later, the B3 brake 74 constitutes an engagement side frictional engagement device that is engaged during a downshift, and the C2 clutch 76 constitutes a disengagement side frictional engagement device that is released during a downshift. To do.

  The first set 50 includes a single pinion type planetary gear mechanism. The first set 50 includes a sun gear S (UD) 51, a pinion gear 52, a ring gear R (UD) 53, and a carrier C (UD) 54.

  Sun gear S (UD) 51 is connected to turbine 44 of torque converter 3 via input shaft 48. The pinion gear 52 is rotatably supported by the carrier C (UD) 54. Pinion gear 52 is engaged with sun gear S (UD) 51 and ring gear R (UD) 53.

  The ring gear R (UD) 53 can be fixed to the gear case 71 by a B3 brake 74. Carrier C (UD) 54 can be fixed to gear case 71 by B1 brake 72.

  The second set 60 is constituted by a Ravigneaux type planetary gear mechanism. The second set 60 includes a sun gear S (D) 61, a short pinion gear 62, a carrier C (1) 63, a long pinion gear 64, a carrier C (2) 65, a sun gear S (S) 66, and a ring gear R. (1) (R (2)) 67.

  Sun gear S (D) 61 is connected to carrier C (UD) 54. The short pinion gear 62 is rotatably supported by the carrier C (1) 63. Short pinion gear 62 is engaged with sun gear S (D) 61 and long pinion gear 64. The carrier C (1) 63 is connected to the output gear 70.

  Long pinion gear 64 is rotatably supported by carrier C (2) 65. Long pinion gear 64 is engaged with short pinion gear 62, sun gear S (S) 66, and ring gear R (1) (R (2)) 67. The carrier C (2) 65 is connected to the output gear 70.

  The sun gear S (S) 66 can be connected to the input shaft 48 via the C1 clutch 75. The ring gear R (1) (R (2)) 67 can be fixed to the gear case 71 by the B2 brake 73, and can be connected to the input shaft 48 by the C2 clutch 76. Further, the ring gear R (1) (R (2)) 67 is connected to the one-way clutch F77, and the gear stage is at the first speed and cannot rotate during driving.

FIG. 3 is an operation table of the automatic transmission according to the embodiment of the present invention.
In FIG. 3, “◯” represents engagement. “X” represents release. “◎” represents engagement only during engine braking. “Δ” represents engagement only during driving. By operating the brakes and the clutches by exciting and de-energizing linear solenoid valves SL1 to SL5 provided in the hydraulic control circuit 9 (see FIG. 1) and a transmission solenoid (not shown) in the combinations shown in the operation table. First to sixth forward gears and reverse gears are formed.

  In the present embodiment, when the automatic transmission 5 forms a fourth gear (4th), the C1 clutch 75 and the C2 clutch 76 are engaged as shown in the operation table. . From this state, for example, when a downshift to the third gear (3rd) is instructed by the driver operating the shift lever 28 (see FIG. 1), the transmission ECU 12 controls the automatic transmission 5, While the C2 clutch 76 is released, the gripping for engaging the B3 brake 74 is executed.

  Therefore, in the downshift from the fourth speed to the third speed, the B3 brake 74 according to the present embodiment constitutes an engagement-side friction engagement device that is engaged during the downshift, and the C2 clutch 76 is the downshift. A release side frictional engagement device that is sometimes released is configured. Similarly, in a downshift between other shift speeds, the friction engagement device that shifts from the released state to the engaged state constitutes the engagement side frictional engagement device according to the present invention, and the engaged state is released from the engaged state. The frictional engagement device that shifts to constitutes the release-side frictional engagement device according to the present invention.

  The shift lever 28 (see FIG. 1) has a D position corresponding to a drive range (hereinafter simply referred to as a D range), an N position corresponding to a neutral range, and an R position corresponding to a reverse range from the rear to the front of the vehicle. The P position corresponding to the parking range is taken.

  When the shift lever 28 (see FIG. 1) is located in the D range, the gear stage forms one of the first to sixth gears. As described above, the transmission ECU 12 The gear stage is selected based on the vehicle speed and the throttle opening.

  The shift lever 28 (see FIG. 1) further includes an M position representing a manual position for shifting the gear stage of the automatic transmission 5 (see FIG. 1) in the manual shift mode, and a plus position (instruction for instructing an upshift). + Position) and a minus position (-position) for instructing a downshift. The M position is located beside the D position, and when the shift lever 28 (see FIG. 1) is moved laterally from the D position, it is held at the M position by a spring (not shown). .

  FIG. 4 is a circuit diagram showing a schematic configuration of the hydraulic control circuit according to the embodiment of the present invention.

  As shown in FIG. 4, the hydraulic oil pumped from the oil pump 38 is regulated by the relief-type first pressure regulating valve 40 to become the first line pressure PL1. The oil pump 38 is constituted by, for example, a mechanical pump that is rotationally driven by the engine 2.

  The hydraulic oil having the first line pressure PL1 is supplied to the manual valve 39 that is interlocked with the shift lever 28 (see FIG. 1). When the shift lever 28 is located at a position corresponding to the forward range, hydraulic oil having a forward position pressure PD equal to the first line pressure PL1 is supplied from the manual valve 39 to the linear solenoid valves SL1 to SL5. It has become.

  The linear solenoid valves SL1 to SL5 are arranged to correspond to the C1 clutch 75, the C2 clutch 76, the B1 brake 72, the B2 brake 73, and the B3 brake 74, respectively. The transmission ECU 12 adjusts the hydraulic pressures PC1, PC2, PB1, PB2, and PB3 by controlling these linear solenoid valves SL1 to SL5 with a solenoid current, and the C1 clutch 75, the C2 clutch 76, the B1 brake 72, and the B2 brake 73 are adjusted. , Switching the engagement and release of the B3 brake 74, and adjusting the engagement pressure.

  Hereinafter, a characteristic configuration of a transmission ECU constituting a shift control device for an automatic transmission according to an embodiment of the present invention will be described with reference to FIG. In the following description, a case where the vehicle 1 is downshifted from the fourth gear to the third gear in response to a downshift instruction from the shift lever 28 will be described as an example.

  The transmission ECU 12 detects a signal indicating a downshift instruction via the operation position sensor 29 when the shift lever 28 moves to the minus position. Therefore, the transmission ECU 12 according to the present embodiment constitutes an instruction detection unit according to the present invention.

  When the transmission ECU 12 detects a signal indicating a downshift instruction, the transmission ECU 12 transmits an instruction to execute torque increase to the engine ECU 11 so that the engine 2 executes torque increase. Further, as will be described later, when a predetermined time has elapsed since the transmission ECU 12 detects the downshift instruction, the transmission ECU 12 starts to decrease the torque amount and sets the engine ECU 11 to end the torque increase before the shift is completed. The engine 2 is controlled via this.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a torque-up control unit according to the present invention.

  Further, when the transmission ECU 12 detects a signal indicating a downshift instruction, the engagement-side friction is caused so that the input shaft rotational speed, that is, the turbine rotational speed NT approaches the preset target value of the change speed at a timing described later. The engagement pressure for the engagement device is controlled. Specifically, when the transmission ECU 12 detects a signal indicating a downshift instruction, the transmission ECU 12 immediately reduces the hydraulic pressure PC2 for the C2 clutch 76 that constitutes the disengagement side frictional engagement device, and the engagement side frictional engagement device. The engagement pressure PB3 with respect to the B3 brake 74 is controlled so that the changing speed of the turbine rotation speed approaches a preset target value. At this time, the transmission ECU 12 corrects the engagement pressure based on a shift control process (see FIG. 7) described later.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a hydraulic control means according to the present invention.

  Further, the transmission ECU 12 acquires the turbine rotational speed NT input from the turbine rotational speed sensor 30 at a predetermined time interval. Further, the transmission ECU 12 takes the difference between the turbine rotational speed NT acquired from the turbine rotational speed sensor 30 at two time points T2 and T4 (see FIG. 5), which will be described later, during downshift transmission control, and calculates the difference from T2. By dividing by the time until T4, the actual change speed of the turbine rotational speed NT is calculated.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a change speed calculation means according to the present invention.

  Further, the transmission ECU 12 calculates the amount of torque output from the engine 2 during execution of the torque increase described above.

  Specifically, the transmission ECU 12 receives a signal representing the throttle opening from the throttle sensor 24 and a signal representing the engine speed NE from the engine speed sensor 21. The transmission ECU 12 calculates the torque amount output from the engine 2 based on the throttle opening degree and the engine speed NE and the torque amount map stored in the ROM. The torque amount map is obtained by experimental measurement for the engine 2 mounted on the vehicle 1 and is stored in advance in the ROM.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a torque amount calculating means according to the present invention.

  Further, the transmission ECU 12 sets a target change speed of the turbine rotational speed NT according to the calculated torque amount and the vehicle speed. Specifically, when the transmission ECU 12 calculates the amount of torque as described above and acquires a signal representing the vehicle speed from the vehicle speed sensor 25, the turbine is referred to a target ΔNT setting map (see FIG. 6) as described later. A target ΔNT representing a target change speed with respect to the rotational speed NT is set.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a target change speed setting means according to the present invention.

  Further, the transmission ECU 12 calculates a deviation between the actual change speed of the turbine rotation speed NT calculated as described above and the target change speed, and stores this deviation in the RAM as a learning value. Then, the transmission ECU 12 corrects the engagement pressure PB3 for the B3 brake 74 constituting the engagement side frictional engagement device in accordance with the learned value when the next downshift shift control is executed. Yes. The correction amount of the engagement pressure corresponding to the learning value is obtained in advance by experimental measurement, and is stored in the ROM as a correction amount map.

  Therefore, the transmission ECU 12 according to the present embodiment constitutes a hydraulic pressure correction unit according to the present invention.

  FIG. 5 is a timing chart for illustrating the control timing of the transmission ECU according to the embodiment of the present invention.

  Here, the graph (a) represents the change in the instructed gear stage that is instructed by the shift lever 28. Graph (b) represents the change in turbine speed NT during downshifting. Graph (c) represents a change in the engagement side hydraulic pressure, and in the present embodiment, a change in the engagement pressure PB3 with respect to the B3 brake 74. Further, the graph (d) represents a change in the requested torque-up amount requested from the engine 2 by the transmission ECU 12 via the engine ECU 11. Further, the graph (e) represents the change in the torque amount actually output from the engine 2 in accordance with the torque increase request amount.

  When the transmission ECU 12 acquires a signal indicating a downshift instruction from the shift lever 28 at time T0 (see graph (a)), the disengagement hydraulic pressure supplied to the C2 clutch 76 is quickly reduced to "0". Let Further, the transmission ECU 12 stores the turbine rotational speed acquired from the turbine rotational speed sensor 30 in the RAM as the turbine rotational speed NT [0]. Further, the transmission ECU 12 acquires a signal representing the vehicle speed from the vehicle speed sensor 25. Note that acquisition of a signal representing the vehicle speed may be executed, for example, when the torque is increased.

  Next, at time T1, the transmission ECU 12 increases the engagement-side hydraulic pressure to a predetermined first fill pressure and rapidly fills the hydraulic oil (see graph (c)).

  Then, the transmission ECU 12 requests the engine ECU 11 to increase the torque of the engine 2 (see graph (d)). Specifically, the transmission ECU 12 calculates the torque-up request amount by referring to the torque-up request amount stored in advance in the ROM based on parameters such as the current gear stage, the required gear stage, and the current vehicle speed. It is like that. Then, the transmission ECU 12 transmits a signal indicating the calculated torque increase request amount to the engine ECU 11.

  When the engine ECU 11 acquires a signal indicating the torque increase request amount, the engine ECU 11 controls the opening degree of the throttle valve 31 in accordance with the torque increase request amount, and increases the torque amount output from the engine 2. At this time, the actual torque amount actually output from the engine 2, that is, the engine torque Te fluctuates due to a change in the traveling environment of the vehicle 1 (see graph (e)).

  Next, at time T2, the transmission ECU 12 maintains the engagement side hydraulic pressure at a predetermined constant pressure standby pressure (see graph (c)), and increases the turbine speed NT with the engagement pressure at this time (graph (b)). See) Progress downshift.

  At this time, the transmission ECU 12 acquires signals representing the engine speed and the throttle opening from the engine speed sensor 21 and the throttle sensor 24 respectively, and refers to the engine torque map stored in the ROM, whereby the engine torque Te. Is calculated and stored in the RAM. The calculated engine torque Te is used for calculating the target ΔNT as will be described later.

  Next, the transmission ECU 12 starts calculating the change gradient ΔNT of the turbine speed NT at time T3. Specifically, if the turbine rotational speed input from the turbine rotational speed sensor 30 reaches a value obtained by adding a predetermined value α to the turbine rotational speed NT [0] stored in the RAM, the transmission ECU 12 Immediately after this time, the turbine rotational speed acquired from the turbine rotational speed sensor 30 is stored in the RAM as the turbine rotational speed NT [A]. At the same time, the transmission ECU 12 starts timing by a timer. The predetermined value α is based on the detection accuracy of the turbine rotational speed sensor 30 and the like, although the turbine rotational speed NT has not actually started increasing, the transmission ECU 12 has started increasing the turbine rotational speed NT. It is set to a value that can prevent erroneous determination.

  Note that the transmission ECU 12 may acquire the turbine rotational speed NT [A] when a predetermined time has elapsed from the time T0. In this case, the transmission ECU 12 starts the time measurement for acquiring the turbine speed NT [A] at the time T0 by the timer.

  Next, the transmission ECU 12 requests the engine ECU 11 to start a decrease in torque increase at time T4. The engine ECU 11 controls the throttle valve 31 so that the torque increase request amount becomes “0” at time T6 (see graph (d)). Here, the time T6 means a time point immediately before the turbine speed NT reaches the synchronous rotation after the shift.

  Next, when the measurement time T elapses from time T3 and reaches time T5, the transmission ECU 12 stores the turbine rotational speed at this time in the RAM as the turbine rotational speed NT [B]. Thereby, the transmission ECU 12 can calculate the change speed of the turbine rotational speed NT as an actual ΔNT using the turbine rotational speeds NT [A] and NT [B] stored in the RAM and the measurement time T. It becomes possible.

  Next, the transmission ECU 12 starts increasing the engagement side hydraulic pressure when the turbine rotational speed NT reaches around the synchronous rotational speed of the post-shift gear stage at time T6 (see graph (c)).

  Next, when the transmission ECU 12 determines at time T7 that the turbine rotational speed NT has reached the synchronous rotational speed of the post-shift gear stage and the shift has been completed, the transmission ECU 12 increases the engagement side hydraulic pressure to the first line pressure PL1. (See the graph (c)), and the shift control is finished.

  Then, the transmission ECU 12 calculates a deviation between the actual ΔNT and the target ΔNT based on the actual ΔNT acquired in the current shift control and a target ΔNT setting map (see FIG. 6) described later, and stores it in the RAM as a learning value. It comes to memorize. And transmission ECU12 correct | amends the engagement side hydraulic pressure in the next downshift according to the learning value memorize | stored in RAM.

  FIG. 6 is a diagram showing a target ΔNT setting map according to the embodiment of the present invention.

  The target ΔNT setting map associates the engine torque Te and the vehicle speed with the target ΔNT, and is stored in the ROM in advance.

  The transmission ECU 12 stores in the ROM two maps, a map corresponding to the engine torque Te = Te1 shown in FIG. 6A and a map corresponding to the engine torque Te = Te2 shown in FIG. 6B. It has become. Here, the engine torque Te1 represents the minimum engine torque that can be assumed based on the traveling environment of the vehicle as the actual engine torque at the time of downshift, and the engine torque Te2 represents the vehicle as the actual engine torque at the time of downshift. Represents the maximum engine torque that can be assumed based on the driving environment.

  When the transmission ECU 12 acquires a signal representing the vehicle speed from the vehicle speed sensor 25, the transmission ECU 12 acquires the target ΔNT from the map shown in FIG. 6A and the map shown in FIG. Next, the transmission ECU 12 calculates a ratio of the engine torque Te calculated by the method described above to the engine torques Te1 and Te2. Then, the target ΔNT obtained by applying the calculated ratio to the two target ΔNTs acquired as described above is set as the target ΔNT for the engine torque Te.

  Note that the value of the target ΔNT in the target ΔNT setting map according to the present embodiment is set to be higher in the case of Te2 than Te1, and is set to be higher as the vehicle speed increases. Accordingly, in the map shown in FIG. 6, the relationships A1 <A2, B1 <B2, and C1 <C2 are established, and in the map shown in FIG. 6A, the relationship A1 <B1 <C1 is shown. In the map shown in FIG. 6B, the relationship of A2 <B2 <C2 is established.

  FIG. 7 is a flowchart for explaining the shift control process according to the embodiment of the present invention. The following processing is executed when the transmission ECU 12 acquires a downshift request from the shift lever 28, and implements a program that can be processed by the CPU.

  First, the transmission ECU 12 determines whether or not a measurement start condition is satisfied (step S11). Specifically, when the transmission ECU 12 obtains a downshift speed change request from the shift lever 28 via the operation position sensor 29, the transmission ECU 12 obtains a signal representing the turbine revolution speed from the turbine revolution speed sensor 30, and the turbine revolution speed is obtained. Store in the RAM as NT [0]. Further, the transmission ECU 12 increases the torque for the engine 2 by the method described above.

  Then, the transmission ECU 12 determines that the measurement start condition is satisfied when the signal acquired from the turbine speed sensor 30 becomes NT [0] + α.

  If the transmission ECU 12 determines that the measurement start condition is satisfied (Yes in step S11), the transmission ECU 12 proceeds to step S12. On the other hand, when the transmission ECU 12 determines that the measurement start condition is not satisfied (No in step S11), the transmission ECU 12 repeats this step.

  As described above, the transmission ECU 12 at this time point is based on the engine speed and throttle opening respectively input from the engine speed sensor 21 and the throttle sensor 24 and the engine torque map stored in advance in the ROM. Thus, the engine torque Te output from the engine 2 due to the torque increase is calculated.

  Next, the transmission ECU 12 acquires the turbine rotational speed NT [A] (step S12). Specifically, when determining that the measurement start condition is satisfied in step S11, the transmission ECU 12 acquires the turbine rotational speed from the turbine rotational speed sensor 30, and stores it in the RAM as the turbine rotational speed NT [A]. At this time, the transmission ECU 12 starts timing by a timer.

  Next, the transmission ECU 12 determines whether a measurement end condition is satisfied (step S13). Specifically, the transmission ECU 12 determines whether or not the time measured by the timer started in step S12 has passed the measurement time T.

  When the transmission ECU 12 determines that the time measured by the timer has passed the predetermined measurement time T, the transmission ECU 12 proceeds to step S14. On the other hand, if the transmission ECU 12 determines that the time measured by the timer has not passed the measurement time T, this step is repeated.

  Next, the transmission ECU 12 acquires the turbine rotational speed from the turbine rotational speed sensor 30, and stores it in the RAM as the turbine rotational speed NT [B] (step S14).

Next, the transmission ECU 12 calculates a change gradient ΔNT of the turbine rotational speed NT (step S15). Specifically, the transmission ECU 12 acquires the turbine speeds NT [A] and NT [B] stored in the RAM. And according to the following formula | equation (1), change gradient (DELTA) NT of turbine speed NT is calculated as real (DELTA) NT.
ΔNT = (NT [B] −NT [A]) / T (1)

  Next, the transmission ECU 12 calculates a target ΔNT based on the vehicle speed and the engine torque Te during blipping (step S16). Specifically, the transmission ECU 12 obtains the signal representing the vehicle speed output from the vehicle speed sensor 25 and the engine torque Te during torque-up, that is, during blipping, stored in the RAM in step S11, as shown in FIG. The target ΔNT is calculated based on the map. At this time, the transmission ECU 12 acquires the target ΔNT corresponding to the acquired vehicle speed from the maps shown in FIGS. 6 (a) and 6 (b). Then, the target ΔNT corresponding to the engine torque Te stored in the RAM is calculated by interpolating the target ΔNT acquired from the maps shown in FIGS. 6 (a) and 6 (b). The interpolation method is not limited to the above-described proportional method, and a known interpolation method using a quadratic function or other functions may be used.

  Next, the transmission ECU 12 determines whether or not the actual ΔNT calculated in step S15 is greater than or equal to the target ΔNT calculated in step S16 (step S17).

  If the transmission ECU 12 determines that the actual ΔNT is equal to or greater than the target ΔNT (Yes in step S17), the transmission ECU 12 subtracts the correction hydraulic pressure ΔP ′ from the engagement hydraulic pressure P in the current downshift and sets the value in the next downshift. The engagement side hydraulic pressure is set (step S18). The corrected hydraulic pressure ΔP ′ is set according to the difference between the actual ΔNT and the target ΔNT, that is, the target deviation. The corrected hydraulic pressure ΔP ′ for the target deviation is determined in advance by experimental measurement and is stored in the ROM as a corrected hydraulic pressure map.

  On the other hand, if the transmission ECU 12 determines that the actual ΔNT is less than the target ΔNT (No in step S17), the value obtained by adding the correction hydraulic pressure ΔP to the engagement-side hydraulic pressure P in the current downshift is set to the next downshift. The engagement side hydraulic pressure is set to (step S19).

  As described above, in the shift control device for an automatic transmission according to the embodiment of the present invention, the amount of torque output from the engine 2 due to a change in the travel environment during execution of torque increase in downshift is reduced. Even when the torque amount deviates from the requested amount of torque, the engagement side hydraulic pressure can be learned according to the amount of torque actually output from the engine 2. Therefore, even when a shift in which the power source is torque-up during a downshift is executed, the learning accuracy for the engagement side hydraulic pressure can be improved and the drivability during the shift can be improved.

  In addition, when a predetermined time elapses from the start of the shift control, the degree of contribution of the change speed of the input shaft rotation speed controlled by the engagement side hydraulic pressure increases from the degree of contribution controlled by the torque increase. It is possible to execute high speed shift control.

  In addition, since the torque amount at the time of torque up that affects the actual change speed is accurately calculated, it is possible to set the target change speed in a state where the target change speed includes fluctuations according to the running state of the actual torque amount. It becomes possible. Therefore, learning of the deviation between the target change speed and the actual change speed becomes accurate, and as a result, the learning accuracy with respect to the engagement-side hydraulic pressure can be improved and the drivability at the time of shifting can be improved.

  In the above description, the case where the shift control device for an automatic transmission according to the present invention is applied to a vehicle equipped with an engine as a power source has been described. However, the shift control device for an automatic transmission according to the present invention may be applied to a vehicle equipped with a motor generator as a power source, or a vehicle equipped with an engine and a motor generator.

  In the above description, the case where the target ΔNT is calculated by interpolating the target ΔNT acquired from the two target ΔNT setting maps shown in FIGS. 6A and 6B has been described. However, the transmission ECU 12 stores two or more target ΔNT setting maps in the ROM, and sets the target ΔNT based on the target ΔNT setting map corresponding to the engine torque closest to the calculated engine torque Te. Also good.

  As described above, the shift control device for an automatic transmission according to the present invention increases the learning accuracy of the engagement side hydraulic pressure and improves the drivability during a shift even when the torque of the power source is increased during a downshift. This is useful for a shift control device for an automatic transmission that can be instructed to downshift by a shift lever.

1 vehicle 2 engine (power source)
3 Torque converter 4 Transmission mechanism 9 Hydraulic control circuit 11 Engine ECU
12 Transmission ECU (shift control device, instruction detection means, torque up control means, hydraulic pressure control means, change speed calculation means, torque amount calculation means, target change speed setting means, hydraulic pressure correction means)
21 Engine speed sensor 22 Intake air amount sensor 23 Intake air temperature sensor 24 Throttle sensor 25 Vehicle speed sensor (vehicle speed detection means)
26 Cooling water temperature sensor 27 Brake sensor 28 Shift lever 29 Operation position sensor 30 Turbine speed sensor 31 Throttle valve 33 Oil temperature sensor 41 Engine output shaft 43 Impeller 44 Turbine 45 One-way clutch 46 Stator 48 Input shaft 70 Output gear 71 Gear case 72 B1 Brake 73 B2 Brake 74 B3 Brake (engagement side friction engagement device)
75 C1 clutch 76 C2 clutch (release side frictional engagement device)

Claims (4)

For an automatic transmission that is connected to a power source via an input shaft and that has a plurality of hydraulic friction engagement devices selectively engaged to establish a plurality of gear stages having different gear ratios, An automatic transmission that performs a downshift shift control that releases a predetermined disengagement side frictional engagement device among the hydraulic engagement devices while engaging the predetermined engagement side frictional engagement device and torque-up the power source. In the gear shift control device of the machine,
Instruction detection means for detecting an instruction of the downshift;
Vehicle speed detection means for detecting a vehicle speed when a downshift instruction is detected by the instruction detection means;
Torque up control means for executing torque up for the power source triggered by detection of a downshift instruction by the instruction detection means, and controlling a torque amount in the torque up;
A hydraulic control means for controlling an engagement side hydraulic pressure to be supplied to the engagement side frictional engagement device in accordance with a target change speed predetermined with respect to the input shaft rotation speed in the downshift;
A change speed calculating means for calculating an actual change speed of the input shaft speed in the downshift;
Torque amount calculating means for calculating a torque amount output from the power source during execution of the torque increase;
Target change speed setting means for setting a target change speed of the input shaft rotational speed in accordance with the torque amount calculated by the torque amount calculation means and the vehicle speed detected by the vehicle speed detection means;
A shift control apparatus for an automatic transmission, comprising: a hydraulic pressure correction unit that learns a deviation between the actual change speed and the target change speed and corrects the engagement side hydraulic pressure according to the learned deviation. .   2. The automatic shift according to claim 1, wherein the torque-up control means starts a decrease in the torque amount in the torque-up when a predetermined time has elapsed after the downshift instruction is detected. Gear shift control device.   The automatic torque-up control unit according to claim 2, wherein the torque-up control means reduces the amount of torque so that the torque-up is completed before the input shaft rotational speed reaches the synchronous rotational speed after completion of the downshift. A transmission control device for a transmission.   The torque amount calculation means calculates the torque amount output from the power source after the torque increase is started by the torque increase control means and before the torque amount starts to decrease. A shift control apparatus for an automatic transmission according to any one of claims 1 to 3.

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