JP4363456B2 - Control device for automatic transmission - Google Patents

Abstract

A control apparatus includes: a gear-shift prediction unit (31) that predicts whether a power-on downshift using a clutch-to-clutch shift operation needs to be performed as a next gear-shift; and a standby pressure supply control unit (32) that supplies a pressure for placing a first friction engaging element, which contributes to the next gear-shift, in the standby state, which is achieved immediately before engagement of the first friction engaging element is started, to the first friction engaging element, when the gear shift prediction unit (31) predicts that the power-on downshift using the clutch-to-clutch shift operation needs to be performed as the next gear-shift. When it is determined that a condition for performing the next gear-shift is satisfied based on the accelerator operation and the vehicle drive state, a shift command signal (Ia to Ie) is output to bring the first friction engaging element out of the standby state and engage the first friction engaging element

Description

  The present invention relates to a control device for an automatic transmission, and more particularly to a control device for an automatic transmission designed to achieve both reduction of shift shock and ensuring responsiveness to a sudden acceleration request.

  In an automatic transmission for a vehicle, a shift determination is made based on a driving state such as a vehicle speed and an accelerator opening degree and a traveling state. Therefore, when the accelerator opening degree suddenly increases or an uphill traveling to a steep slope road starts, A downshift to a shift stage that is two or more steps away from the current shift stage may be required. In such a case, a shift shock is likely to occur. Shift shocks can be reduced by performing a shift in order so that the downshift to the finally required shift stage is performed after the first downshift to the intermediate shift stage is performed. It will be long.

  In addition, some automatic transmissions for vehicles include a combination of a main transmission unit with a low number of shift stages and an auxiliary transmission unit that can be switched between high and low, and a multi-stage with a relatively simple configuration. If a simultaneous shift is performed such that one of the main and sub transmission units is upshifted and the other is downshifted, a shift shock is likely to occur. Also in this case, the shift shock can be reduced by first downshifting one of the transmission units and then downshifting the other transmission unit, but the shift time becomes longer.

  In view of this, conventionally, there has been proposed an automatic transmission control device that achieves both reduction of shift shock and ensuring of responsiveness to a sudden acceleration request.

  As a conventional control device for this type of automatic transmission, for example, when a first shift determination is made such that one of the main and sub transmission units is upshifted and the other is downshifted, the engine is It is determined whether or not the load change speed is equal to or higher than a predetermined value, and when the engine load change speed is equal to or higher than the predetermined value, it is predicted that a second shift determination different from the present will be made, and output for the first shift It is known that the second shift is executed when the second shift is judged without waiting for the second shift to be executed, so that the shift time is shortened (for example, patents). Reference 1).

  In addition, when air discharge control is executed in a hydraulic control circuit of an automatic transmission capable of shifting a clutch-to-clutch (clutch-to-clutch) by releasing one clutch and engaging the other clutch, the air discharge control is performed. In order to avoid the problem that the engagement hydraulic pressure of the friction engagement element becomes higher than usual when the engagement / engagement is required with respect to the friction engagement element in the middle, the shift shock is generated. In some cases, the occurrence of shift determination is predicted and air discharge control is not executed when the shift occurs (see, for example, Patent Document 2).

  Furthermore, in an automatic transmission having main and sub transmission units, it is necessary to supply hydraulic pressure to the friction engagement elements of the main and sub transmission units at the next shift, so that the sub transmission is downshifted to a low speed. In such a case, since the shift shock becomes large, in such a case, a predetermined holding pressure is set in advance in the hydraulic clutch on the side of the sub-transmission to be shifted next (for example, (See Patent Document 3).

Also, in order to reduce unnecessary engagement torque of the frictional engagement element and shorten the engagement delay, the possibility of engagement for each frictional engagement element at the next shift is determined, and the friction is determined according to the determination result. A device that controls the piston position of the engaging element is also known (see, for example, Patent Document 4).
JP 05-99310 A JP 2003-148603 A JP 2001-173771 A JP 2005-265063 A

  However, in the conventional automatic transmission control device as described above, for example, when the vehicle enters an uphill running on a steep slope and enters a sudden deceleration state or the accelerator operation continues, the current gear position is changed. It is necessary to downshift to two or more shift stages, and the downshift is a power-on downshift by clutch-to-clutch shift (downshift in a power-on state in which power is transmitted from the engine to the drive wheels). If the accelerator pedal is depressed slowly by the driver, or if the amount of accelerator pedal depression (accelerator opening increase) is insufficient, the next gear position that is two or more steps away from the current gear position is required. Is not made at once, downshifted from 4th to 3rd, then downshifted from 3rd to 2nd Order gear such as is has been made.

  In other words, if a power-on downshift is executed by a clutch-to-clutch shift without using a one-way clutch that takes down-synchronization timing, and the next shift is started during the first shift, The time required for the engagement-side frictional engagement element to generate a predetermined engagement torque (torque capacity) cannot be secured, and the turbine rotation speed cannot reach the timing synchronized with the gear stage after the next shift. Since the next shift will be performed and a noticeable shift shock will occur, the first shift will be completed even if it is time to pass the down line of the next shift in the shift diagram during the first power-on downshift. Until then, it is necessary to delay the supply of the engagement pressure to the friction engagement element on the engagement side of the next shift.

  For this reason, even if the driver intends to perform an accelerator operation suitable for changes in the driving state, the response of the driving force to the accelerator operation may not be ensured and a good acceleration feeling may not be obtained. Recently, automatic transmissions that are becoming more and more difficult to meet the high demands for drivability.

  Therefore, the present invention provides a high response even when a power-on downshift is performed by clutch-to-clutch shift without using a one-way clutch, and a downshift to a shift stage that is two or more steps away is prevented while preventing a shift shock. An object of the present invention is to provide a control device for an automatic transmission that can be executed and has improved responsiveness of driving force to accelerator operation.

In order to achieve the above object, the automatic transmission control device of the present invention (1) selectively engages and disengages a plurality of hydraulic friction engagement elements of the automatic transmission according to the accelerator operation and the driving state of the vehicle. In a control device for an automatic transmission that outputs a shift instruction signal to execute shift control, the engagement of one friction engagement element and the release of the other friction engagement element of the plurality of friction engagement elements are involved. A shift prediction unit that predicts that a power-on downshift by clutch-to-clutch shift is required as the next shift, and a power-on downshift by the clutch-to-clutch shift by the shift prediction unit is predicted as the next shift Standby hydraulic pressure supply means for supplying the hydraulic pressure for setting the standby state immediately before starting the engagement to the one friction engagement element that executes the next shift when The waiting time of supplying the oil pressure to said standby state to the friction engagement element of the one by the hydraulic pressure supply means, determining whether said next speed change prediction by the gear shift prediction unit is maintained at a predetermined time interval Predictive maintenance determining means for performing the next shift according to the accelerator operation and the driving state of the vehicle when the predictive maintenance determining means determines that the prediction of the next shift is maintained. When the condition to perform is established, the one frictional engagement element is engaged from the standby state, and when the prediction maintenance determination unit determines that the prediction of the next shift is not maintained, the standby hydraulic pressure is determined. The supply means is configured to drain the hydraulic pressure that is supplied to the one frictional engagement element and enters the standby state .

  With this configuration, when a power-on downshift due to clutch-to-clutch shift is predicted as the next shift, a standby state (hydraulic piston immediately before starting engagement with the friction engagement element on the engagement side of the next shift in advance) The hydraulic pressure for supplying the friction plate to a sliding state in which the friction plate has not reached an effective frictional engagement torque even when the stroke end on the engagement side has been reached. Accordingly, even if the time until the next shift is short, the pressure increase time until the hydraulic pressure in the standby state is shortened, so that when the execution condition for the next shift is satisfied and the shift instruction signal is output, the friction engagement on the engagement side is performed. The element is immediately engaged from the standby state, and there is no need to delay the shift instruction signal output. As a result, the delay in starting the next shift is prevented, and the response of the driving force to the driver's operation can be improved.

In addition, even when the standby hydraulic pressure is supplied to one friction engagement element, the prediction of the next shift is maintained, and when the execution condition for the next shift is satisfied, the one friction engagement element is in the standby state. When engaged from the state, but the prediction of the next shift is not maintained, the standby hydraulic pressure supplied to one friction engagement element is drained. Therefore, the frictional engagement element is prevented from being rubbed by unnecessary standby hydraulic pressure, and the oil temperature is prevented from rising and the friction material is prevented from deteriorating.

(1) The automatic transmission control device according to (1) includes: (2) a first time during which the shift prediction means continues to increase the accelerator opening by the accelerator operation, and the driving state of the vehicle is the automatic shift. The power-on downshift by the clutch-to-clutch shift is required as the next shift based on at least one of the second time changing in the direction approaching the down line on the shift diagram of the machine It may be predicted to become.

  With this configuration, it is possible to accurately detect a state in which the next shift is predicted.

(1) The control device for the automatic transmission according to any one of (1) and (2) includes: (3) While the current shift is being executed according to the accelerator operation and the driving state of the vehicle, the shift prediction means When a power-on downshift due to the clutch-to-clutch shift is predicted as a next shift, a predicted wait time calculation that calculates a predicted wait time until the output of a shift instruction signal for the next shift is performed every first predetermined time Means for supplying the standby hydraulic pressure when the predicted standby time is shorter by a second predetermined time than the pressure increase time required for the one frictional engagement element to be in the standby state immediately before the start of the engagement. Preferably, the means supplies a hydraulic pressure for setting the standby state to the one friction engagement element that performs the next shift.

As a result, one of the friction engagement elements can be put into a standby state immediately before the start of engagement when a shift instruction signal for the next shift is output, and unnecessary friction of the friction engagement element occurs due to unnecessary standby hydraulic pressure. It is prevented that the oil temperature rises or the friction material deteriorates. It should be noted that the second predetermined time here is to release the other frictional engagement element that becomes the release side when the next shift is executed to the standby state immediately before the start of the engagement or slightly to the release side (standby hydraulic pressure). It is preferable that the time is required to reduce the hydraulic pressure to a hydraulic pressure slightly lower than that.

In the control device for the automatic transmission of (3) , (4) the predicted waiting time calculation means passes when the vehicle speed is decelerated from the current vehicle speed and the current vehicle speed on the shift diagram of the automatic transmission. The predicted waiting time may be calculated based on a vehicle speed difference between vehicle speeds when reaching the down line and a deceleration of the vehicle.

  With this configuration, the predicted waiting time is accurately calculated.

In the automatic transmission control device according to (3) or (4) , (5) the predicted standby time calculation means includes the current accelerator opening on the shift diagram of the automatic transmission and the current accelerator opening. The difference between the accelerator opening when the accelerator opening reaches at least one down line that passes when the accelerator opening increases from the accelerator opening, and the amount of change in the accelerator opening per unit time of the vehicle Based on this, the predicted waiting time may be calculated.

  Also with this configuration, the estimated standby time is accurately calculated.

The control device for an automatic transmission according to any one of the above (3) to (5) , further includes: (6) the shift prediction means is configured to perform a second shift from the current shift step based on the accelerator operation and the driving state of the vehicle. Predicting that the power-on downshift described above is required as the next shift and the subsequent shift, and the predicted standby time calculating means performs a first predicted standby until the output of the shift instruction signal for the next shift A second predicted waiting time until the output of the shift instruction signal for the next shift is calculated, and the second predicted waiting time is a predetermined time from the boost time for the subsequent shift. When the time is shortened, the hydraulic pressure for setting the standby state may be supplied to one friction engagement element that performs the successive shifts.

  In this case, when downshifting to a shift stage that is two or more steps away, an engagement that performs successive shifts in consideration of the release timing of the frictional engagement elements that are released during subsequent shifts, changes in the driving state after predicted shifts, etc. The engagement start point of the friction engagement element on the side can be set at a more suitable timing, and the prediction accuracy can be improved if the prediction maintenance determination for the successive shifts is performed from an early stage.

  According to the present invention, when a power-on downshift due to clutch-to-clutch shift is predicted as the next shift, the standby immediately before the start of engagement is established in advance on the friction engagement element on one side (engagement side) of the next shift. When the condition for executing the next shift is satisfied and the shift instruction signal is output by reducing the pressure increase time to the standby hydraulic pressure even if the time until the next shift is short Since the frictional engagement element on the engagement side is immediately engaged from the standby state, there is no need to delay the output of the shift instruction signal as in the prior art, and a shift that is two steps or more away while preventing a shift shock. It is possible to provide a control device for an automatic transmission in which the downshift to the gear stage can be executed with high response, and the responsiveness of the driving force to the accelerator operation is enhanced.

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

  FIG. 1 is an overall block diagram of an automatic transmission control device according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the automatic transmission and the control device. FIG. 3 is a diagram showing a fastening logic table of the automatic transmission according to the embodiment of the present invention, and FIG. 4 is a shift diagram in which the automatic transmission is made into a constant map.

  First, the configuration will be described. As shown in FIG. 1, the vehicle of the present embodiment (automobile not shown) includes an engine 11 that is a prime mover and wheels (running) that are not shown in the figure. An automatic transmission 12 that transmits to the output unit) side is mounted. The automatic transmission 12 includes a torque converter 14, a gear transmission mechanism 15, and a hydraulic control device 16.

  Although not shown in detail, the engine 11 has a combustion chamber partitioned by a piston in each cylinder, for example, as in a known multi-cylinder internal combustion engine, and the intake valve and the exhaust valve are opened and closed at a predetermined timing. A spark plug is disposed so as to be exposed to the combustion chamber. A throttle valve is provided upstream of the intake passage formed by the intake manifold, and an injector (fuel injection device) for injecting fuel is provided between the intake passage and the combustion chamber of each cylinder.

  As shown in FIG. 2, the torque converter 14 has a pump impeller 14a (input side member) connected to the output shaft 11a of the engine 11 via a shell cover 14s, and is opposed to the pump impeller 14a and has a gear transmission 15 The turbine runner 14b (output side member) connected to the transmission input shaft Min, the stator 14c positioned between the pump impeller 14a and the turbine runner 14b, and hydraulic oil contained in the shell cover 14s (not shown) When the hydraulic oil flow is generated by the rotation of the input-side pump impeller 14a driven by the output shaft 11a of the engine 11, the turbine runner 14b receives the inertial force of the flow. The transmission input shaft Min of the gear transmission mechanism 15 is rotated. In addition, the stator 14c rectifies the flow of the hydraulic oil returning from the turbine runner 14b to the pump impeller 14a, so that a torque amplifying action due to the reaction force of the stator 14c can be generated. The torque converter 14 is also provided with a lock-up clutch 14d that can selectively restrain the input-side pump impeller 14a and shell cover 14s and the output-side turbine runner 14b to each other. By doing so, the torque transmission efficiency can be increased. Further, the stator 14c is supported on the gear transmission mechanism 15 side via the one-way clutch 14e and has a structure capable of receiving the reaction force.

  The gear transmission mechanism 15 is composed of, for example, a planetary gear type gear train whose upper half is shown by a skeleton in FIG. 2, and a transmission input shaft Min for inputting rotation from the turbine runner 14b, and a clutch C1 ( A cylindrical first rotary shaft M1 which is selectively connected to the transmission input shaft Min by a reverse clutch) and connected to the transmission case 15h by a brake B1 (2-4 brake), and a transmission input shaft Min. And a cylindrical second rotary shaft M2 provided between the first rotary shaft M1 and selectively connected to the transmission input shaft Min by a clutch C0 (high clutch). A first planetary gear 17 and a second planetary gear 18 are provided.

  The first planetary gear 17 includes a sun gear S1 fixed to the first rotation shaft M1, a ring gear R1 connected to the carrier Cr2 of the second planetary gear 18, a pinion P1 meshing with the sun gear S1 and the ring gear R1, and a second rotation shaft. The carrier Cr1 is coupled to M2 and holds the pinion P1 rotatably, and is locked to the transmission case 15h via the low one-way clutch F1.

  The second planetary gear 18 includes a sun gear S2 fixed to the transmission input shaft Min, a ring gear R2 that is selectively coupled to the carrier Cr1 of the first planetary gear 17 via a clutch C2 (low clutch), the sun gear S2, and the ring gear. The pinion P2 meshes with R2, and the carrier Cr2 that holds the pinion P2 rotatably and is fixed to the ring gear R1 of the first planetary gear 17. Further, the carrier Cr2 is connected to the transmission output shaft Mout and rotates integrally therewith. The rotation of the transmission output shaft Mout of the gear transmission mechanism 15 is transmitted to the wheel side via a differential gear (not shown).

  Although the detailed hydraulic circuit configuration is not illustrated in the hydraulic control device 16, for example, the electromagnetic drive units 61a, 61b, 61c, 61d, and 61e provided corresponding to the plurality of clutches C0, C1, and C2 and the brakes B1 and B2, for example. And control valve parts 62a, 62b, 62c, 62d, 62e for controlling the hydraulic pressures of the plurality of clutches C0, C1, C2 and brakes B1, B2 according to the operating force from at least the electromagnetic drive parts 61a-61e, and automatic A modulator valve 63 that adjusts the line hydraulic pressure from the oil pump 19 provided in the transmission 12 to a predetermined pressure and supplies the pressure to the control valve portions 62a to 62e, and is switched according to the driver's selection operation. When the D (drive) range is selected, the line oil pressure is output to the D range oil passage L1, and the R (reverse) range is output. The time of selection is configured to include a manual valve 64 to be output to the R range oil path L2. Further, the control valve units 62a to 62e have at least the operation force from the electromagnetic drive units 61a to 61e among the operation force from the electromagnetic drive units 61a to 61e, the modulator pressure from the modulator valve 63, and the operation pressure from the manual valve 64. Accordingly, the hydraulic pressures of the plurality of clutches C0, C1, C2 and brakes B1, B2 are controlled.

  Further, the electromagnetic drive units 61a to 61e are each driven in a predetermined combination according to the required shift stage, and the instruction currents Ia, Ib, Ic, The clutches C0 to C2 and the brakes B1 and B2 in the gear transmission mechanism 15 are controlled by Id and Ie (shift control signals) so as to form an optimum shift stage according to a predetermined shift pattern. That is, the clutches C0, C1, and C2 and the brakes B1, B2 are friction engagement elements that can be switched between the engaged state and the released state by the hydraulic control device 16 in accordance with the shift speed to be formed by the gear transmission mechanism 15. As shown in FIG. 3, the engagement and disengagement are performed in a predetermined combination for each gear position.

  FIG. 4 is a shift diagram that defines the basic conditions of the shift control executed by the automatic transmission 12. As shown in FIG. 4, the shift speed of the automatic transmission 12 includes the vehicle speed and the accelerator opening (or throttle throttle). It is determined by the ECU 30 according to a data map of a shift diagram with the opening degree as a parameter. In the figure, the vehicle is upshifted to the high gear position at the vehicle speed and accelerator opening on the upshift line indicated by the solid line, and is downshifted to the low gear stage at the vehicle speed and accelerator opening indicated by the broken line.

  On the other hand, as shown in FIG. 1, the engine 11 includes an accelerator opening sensor 21 that detects a depression amount of an accelerator pedal (not shown), a throttle opening sensor 22 that detects an opening of a throttle valve (not shown), and the engine 11. A water temperature sensor 23 for detecting the cooling water temperature, an intake air amount sensor 24 such as an air flow meter, and an engine speed sensor 25 comprising a crank angle sensor capable of detecting crank rotation at every predetermined angle are mounted.

  Further, on the vehicle body side (not shown), there are a brake pedal sensor 26 that detects the amount of depression of the brake pedal or a pedaling force applied to the brake pedal, and a shift position sensor 27 that detects an operation position of a shift lever provided in the vehicle interior. It is installed.

  A turbine rotation speed sensor 28 for detecting a rotation speed Nt corresponding to the rotation speed of the turbine runner 14 b is provided on the output side of the torque converter 14, and the rotation of the transmission output shaft Mout is provided on the output side of the gear transmission mechanism 15. A vehicle speed sensor 29 for detecting the speed is provided.

  Further, the vehicle according to the present embodiment is provided with a gradient sensor 41 that detects the inclination of the vehicle body from the horizontal posture in the front-rear direction, and a G sensor 42 that detects the acceleration and deceleration of the vehicle.

  Information detected by the sensor groups 21 to 29 and 41 and 42 is taken into an ECU (electronic control unit) 30 which is a transmission computer integrated with the engine control computer.

  The ECU 30 includes a CPU, a ROM, a RAM, a B-RAM (a backup RAM using a battery as a backup power source), an A / D converter, a constant voltage power source, a communication IC, and the like, although a specific hardware configuration is not illustrated. Thus, signals from control computers of other electronic control systems not shown can also be captured. In addition, the ECU 30 controls the plurality of electromagnetic drive units 61a to 61e in the hydraulic control device 16 to change the shift point of the gear transmission mechanism 15 according to the shift position, the vehicle speed, the accelerator opening, and the traveling state of the vehicle. Control, lock-up control of the torque converter 14 and the like are executed, and line hydraulic pressure control of the automatic transmission 12 is executed so as to obtain an optimum line hydraulic pressure according to engine generated torque.

  The ECU 30 also has a power-on downshift by a clutch-to-clutch shift among the clutches C0 to C2 and the brakes B1 and B2 (a plurality of friction engagement elements) as a new plurality of functional units. A shift prediction unit 31 (shift prediction unit) that predicts that it is necessary from a third speed (4th to 3rd in FIG. 3) or a third to second speed (from 3rd to 2nd in FIG. 3); When a power-on downshift due to clutch-to-clutch shift is predicted as the next shift by this function, one friction engagement element that executes the next shift, for example, engagement at the time of downshift from the fourth speed to the third speed Standby clutch C2 or just before starting effective frictional engagement with the engagement-side brake B1 during the downshift from the third speed to the second speed A standby hydraulic pressure supply control unit 32 (standby hydraulic pressure supply means) that supplies hydraulic pressure (hereinafter referred to as standby hydraulic pressure) and a condition for executing the next shift in accordance with the accelerator operation and the driving state of the vehicle, An engagement hydraulic pressure control unit 33 (standby hydraulic pressure supply means) that selectively outputs shift instruction signals Ia to Ie to shift the one friction engagement element from the standby state to the friction engagement state with a predetermined torque capacity; I have.

  Here, the clutch-to-clutch shift is a shift by re-engagement of the friction engagement element, which involves engagement of one friction engagement element and release of the other friction engagement element. Shift that involves switching between clutch C2 and brake B1, such as shifting from 4th to 3rd speed, or switching between clutch C0 and brake B1, such as shifting from 3rd to 2nd in FIG. Shifting is applicable. The power-on downshift is a shift to the low shift stage side in the power transmission state in the gear transmission mechanism 15 of the automatic transmission 12.

  For example, based on detection information from the accelerator opening sensor 21, the throttle opening sensor 22, the vehicle speed sensor 29, and the like, the shift predictor 31 continuously increases the accelerator opening by an operation of increasing an accelerator pedal (not shown). The first time and the second time when the driving state of the vehicle is changing in the direction approaching the down line D21, D32 or D43 on the shift diagram of the automatic transmission 12 are calculated, and the first, first Based on at least one of the two times, it is predicted that a power-on downshift by clutch-to-clutch shift will be required as the next shift. Then, when predicting that a power-on downshift by clutch-to-clutch shift is necessary as the next shift, the shift prediction unit 31 sets a next shift prediction flag to be described later to ON (= 1), and other than that In this case, the next shift prediction flag is set to OFF (= 0).

  Further, as another new functional unit, the ECU 30 determines whether or not the prediction of the next shift by the shift prediction unit 31 is maintained when the standby hydraulic pressure supply controller 32 supplies the standby hydraulic pressure to one friction engagement element. Is provided with a prediction maintenance determination unit 34 (prediction maintenance determination unit), and the engagement hydraulic pressure control unit 33 is determined by the prediction maintenance determination unit 34 to maintain the prediction of the next shift. In this case, when the condition for executing the next shift is established according to the accelerator operation and the driving state of the vehicle, the clutch C2 or the brake B1 which is one of the friction engagement elements is immediately and effectively engaged from the standby state. The standby hydraulic pressure supply control unit 32 is supplied to the clutch C2 or the brake B1, which is one of the friction engagement elements, when the prediction maintenance determination unit 34 determines that the prediction of the next shift is not maintained. The standby hydraulic pressure is drained.

  The standby hydraulic pressure supply control unit 32 constitutes standby hydraulic pressure supply means together with the clutches C0 to C2 and the brakes B1 and B2. The standby hydraulic pressure by the standby hydraulic pressure supply means is achieved by the following configuration, for example.

FIG. 5 is a schematic cross-sectional view of a frictional engagement element according to an embodiment of the present invention.
In each of the clutches C0 to C2 and the brakes B1 and B2 (hereinafter simply referred to as a hydraulic multi-plate friction engagement element in a broad sense) as hydraulic multi-plate friction engagement elements, FIG. Similarly to the hydraulic multi-plate clutch 50 shown, the piston 57 is displaced against the urging force of the return spring 58 within a predetermined stroke range according to the supply hydraulic pressure Pc, and a stopper mounted on the piston 57 and one element 51. 53, a plurality of friction plates 52 supported in a spline-coupled state on one rotating or fixed element 51, and a plurality of friction plates 56 supported in a spline-coupled state on the other rotating or fixed element 55. However, they are fastened and engaged by being pinched together. Further, when the piston 57 of the hydraulic multi-plate clutch 50 is pushed back by the urging force of the return spring 58 as the supply hydraulic pressure is reduced or released, the plurality of friction plates 52 supported by one element 51 and the other element 55 are separated. The hydraulic multi-plate clutch 50 is disengaged by releasing the clamping state with the plurality of supported friction plates 56.

  Further, in the hydraulic control device 16 in the automatic transmission 12, for example, an electromagnetic proportional solenoid valve is used to change the hydraulic pressure supplied to the clutch or the brake including the hydraulic multi-plate clutch 50, thereby the friction plate 52. , 56 and a fully released state in which a substantial gap more than slidable is produced, and there is no gap between the friction plates 52, 56, and a substantial slip (relative rotation) between the one and the other elements 51, 55. Between the friction plates 52 and 56 is less than the predetermined value and sufficient slippage (relative rotation) is obtained between the one and the other elements 51 and 55. A half-engaged state is made possible. This half-engaged state is equivalent to a standby state immediately before the hydraulic multi-plate clutch 50 starts effective engagement to reach the engaged / engaged state, and the hydraulic pressure supplied to the piston 57 of the hydraulic multi-plate clutch 50 in the standby state. The (standby oil pressure) is, for example, about 1/10 to 1/3 of the oil pressure (hereinafter referred to as engagement oil pressure) when the engagement / engagement state is established. In this standby state, the hydraulic multi-plate clutch 50 moves the piston 57 from the fully released state to the engagement side against the urging force of the return spring 58, so that the friction engagement is effective so as to contribute to the change of the gear position. The gap (and the oil film thickness) between the friction plates 52 and 56 can be reduced within the range of the sliding state where no torque is generated.

  The standby hydraulic pressure supply control unit 32 of the ECU 30 selectively supplies the electromagnetic drive units 61a to 61e with a support current for generating the standby hydraulic pressure that is smaller than the command current when the engagement hydraulic pressure is supplied, so that the clutches C0 to C2 and the brake are supplied. One of B1 and B2 which is a friction engagement element on the engagement side of the next shift is set in a standby state.

As yet another function unit, the ECU 30 performs a power-on downshift by the clutch-to-clutch shift by the shift prediction unit 31 while the current shift is being executed according to the accelerator operation and the driving state of the vehicle. When predicted as a shift, a predicted standby time calculation unit 35 (predicted standby time calculation means) calculates a predicted standby time Tpr (see FIG. 7) until the output of a shift instruction signal for the next shift every first predetermined time. ).

Then, the standby hydraulic pressure supply control unit 32 determines whether the predicted standby time Tpr calculated by the predicted standby time calculation unit 35 is a frictional engagement element on the engagement side of the next shift, for example, when downshifting from 4th to 3rd gear. From the pressure increase time Tc (Tc1 or Tc2 in FIG. 7) required until the engagement-side clutch C2 or the engagement-side brake B1 during the downshift from the third speed to the second speed is brought into a standby state immediately before the start of the engagement. When the second predetermined time is shortened, the frictional engagement element on the engagement side of the next shift, for example, the clutch C2 on the engagement side during the downshift from the 4th speed to the 3rd speed or the downshift from the 3rd speed to the 2nd speed The standby hydraulic pressure is supplied to the brake B1 on the engagement side during the shift. The second predetermined time here is the other frictional engagement element that becomes the release side when the next shift is executed, for example, the brake B1 during the downshift from the fourth speed to the third speed or the downshift from the third speed to the second speed. It is necessary to release the clutch C0 at the time of shifting to the standby state just before the start of engagement or slightly to the disengagement side (reducing the hydraulic pressure to the standby hydraulic pressure of the other friction engagement element or slightly lower than that). Although it is about the time, if the supply of the engagement hydraulic pressure to the frictional engagement element on the engagement side of the next shift does not involve a rapid pressure increase when the shift condition is satisfied, the time may be shorter.

  Further, the predicted standby time calculation unit 35 of the ECU 30 includes a current vehicle speed (for example, a point N in FIG. 4) on the shift diagram of the automatic transmission 12 and a down line that passes when the vehicle speed is decelerated from the current vehicle speed, for example, The predicted standby time can be calculated based on the vehicle speed difference between the vehicle speeds when reaching the down line D43 and the deceleration of the vehicle.

  The deceleration mentioned here may be a detection value of the G sensor 42, a deceleration obtained from a change in a detection value of a wheel speed sensor (not shown), a detection value of the vehicle speed sensor 29, or a transmission output. Any of the deceleration obtained from the change in the rotational speed, the presence / absence of increase in the output port pressure of the brake master cylinder (not shown), the detection information from the gradient sensor 41, etc. It may be the vehicle deceleration determined by the method.

  The predicted standby time calculation unit 35 also increases the accelerator opening from the current accelerator opening on the shift diagram of the automatic transmission 12, for example, the accelerator opening at the point N in FIG. 4 and the current accelerator opening. Predicted waiting time Tpr based on the difference in accelerator opening between the accelerator opening when reaching at least one down line, for example, D43, and the amount of change in the accelerator opening per unit time of the vehicle Can also be calculated.

  The standby hydraulic pressure supply control unit 32 of the ECU 30 immediately after the predicted standby time Tpr becomes shorter than a predetermined time, for example, the pressure increase time Tc until the standby state of the engagement side frictional engagement element that performs the next shift. The standby hydraulic pressure starts to be supplied to the engagement side frictional engagement element, but the hydraulic pressure exceeds the standby hydraulic pressure because of the stroke up to the engagement side stroke end (position in the standby state) of the piston 57 as in the case where the shift condition is satisfied. The pressure is not once increased to the hydraulic pressure, but the piston 57 is stroked to the position where the standby pressure is reached by the standby hydraulic pressure. Further, the shift prediction unit 31 performs power-on by clutch-to-clutch shift when the predicted standby time Tpr becomes shorter than the pressure increase time Tc until the standby state of the engagement-side frictional engagement element that performs the next shift. The downshift may be predicted as the next shift. In that case, the next shift flag has a predicted standby time Tpr shorter than the boost time Tc until the standby state of the engagement side frictional engagement element that performs the next shift. At that point, it is set to ON.

  Next, the operation will be described.

FIG. 6 is a flowchart showing a shift control procedure repeatedly executed by the ECU 30 every first predetermined time during the operation of the vehicle in the automatic transmission control apparatus of the present embodiment. In the automatic transmission according to the embodiment, when the two-speed shift is executed from the fourth speed to the third speed and further to the second speed, the change in the input rotational speed of the gear transmission mechanism and the engagement side of each gear stage It is a timing chart which shows the change of the engagement oil pressure of a friction engagement element.

  In the shift control shown in FIG. 6, it is first determined whether or not a next shift prediction flag is ON (step S11).

The next shift prediction flag here is set to ON by the shift prediction unit 31 as follows. For example, (1) A first time (time length) in which the accelerator opening continuously increases by an operation of increasing the accelerator pedal is a predetermined step-up time Tf [msec], for example, several seconds (within 10 seconds) (2) The driving state of the vehicle is changing in a direction approaching the down line D21, D32 or D43 on the shift diagram of the automatic transmission 12, for example, the vehicle continues to decelerate at a certain deceleration. Has reached a predetermined change time , for example, several seconds (within 10 seconds), or (3) the estimated waiting time Tpr until the next shift is the waiting state of the frictional engagement element on the engagement side that performs the next shift. The shift prediction unit 31 sets (sets) the next shift prediction flag to ON when at least one of the conditions (1) to (3) that the pressure increase time Tc is shorter is satisfied. Alternatively, the shift prediction unit 31 sets the next shift prediction flag to ON when one or two specific conditions determined as high priority among the conditions (1) to (3) are satisfied. Alternatively, the next shift prediction flag may be set to ON only when all the conditions are satisfied.

  The state where the next shift flag is set to ON indicates that the power-on downshift by the clutch-to-clutch shift is predicted to be required as the next shift as described above.

If the next shift prediction flag is not set to ON in the first determination step, it is determined again whether or not the next shift prediction flag is ON within the first predetermined time (step S11). That is, this determination step is repeated until the next shift prediction flag is set to ON.

  When the next shift prediction flag is set to ON by the shift prediction unit 31, the determination result in the determination step S11 is YES.

  At this time, for example, assuming that a downshift from the fourth speed to the third speed is being executed as the current speed change operation, the standby hydraulic pressure supply control unit 32 of the ECU 30 performs the friction engagement element on the engagement side of the next speed change, for example, 3 Prior to the next shift, a standby hydraulic pressure equal to or lower than the piston stroke end pressure is supplied to the brake B1, which is an engagement side frictional engagement element at the time of the downshift from the second speed to the second speed (step S12).

  Next, it is determined whether or not the next shift prediction flag is OFF (step S13). That is, it is checked whether the prediction of the next shift is not maintained after the standby hydraulic pressure is supplied to the engagement side frictional engagement element that executes the next shift.

  At this time, if the next shift prediction flag is not OFF and the ON setting of the next shift prediction flag is maintained, then, on the shift diagram which is a constant map stored in the ROM of the ECU 30, the next shift is It is checked whether or not a power-on downshift condition is satisfied (step S14). If the condition is still satisfied, the process returns to the determination step of whether or not the immediately preceding next shift prediction flag is OFF.

  Here, if the shift prediction unit 31 sets the next shift flag to OFF (reset to 0) due to a change in the accelerator operation of the driver or a change in the slope of the uphill road, the standby hydraulic pressure supply control unit 32 sets the next shift. The standby hydraulic pressure of the engagement side clutch (meaning the friction engagement element including the brake) is drained (step S15).

  On the other hand, if the ON setting of the next shift prediction flag is maintained and the condition for the power-on downshift of the next shift is satisfied on the shift diagram, then a shift control signal for executing the shift of the next shift is output. Is done. That is, the command current corresponding to each of the electromagnetic drive units 61a to 61e is supplied according to the predetermined combination shown in FIG. 3 (step S16).

  In such an automatic transmission control apparatus of this embodiment, as shown by a solid line in FIG. 7, for example, even if the time from the current third shift speed to the second shift is short, as shown by the solid line in FIG. The brake B1 that becomes the engagement side at the time of shifting is previously set to the standby state by the standby hydraulic pressure (see the 2nd engagement side hydraulic pressure in FIG. 7), and when the shift instruction signal from the third speed to the second speed is output, the engagement side The brake B1, which is the friction engagement element, has already been boosted to a standby state or a state close thereto. Then, the other frictional engagement element that is disengaged in the shift from the third speed to the second speed, for example, the hydraulic pressure of the clutch C0 is lowered to the standby hydraulic pressure or a pressure slightly lower than that by the shift instruction signal from the third speed to the second speed. When the brake B1 is engaged (see the lowering portion of the 3rd engagement side hydraulic pressure in FIG. 7), the brake B1, which is the engagement side frictional engagement element, is boosted to the standby hydraulic pressure. Thus, the engagement hydraulic pressure is reached and the frictional engagement can be performed immediately.

  On the other hand, the 2nd engagement side hydraulic pressure of the conventional device indicated by the broken line in FIG. 7 starts to be supplied after the gear shift instruction signal from the 3rd speed to the 2nd speed is output, and then waits after the piston stroke is once started above the standby hydraulic pressure. The state is maintained at the hydraulic pressure, and the pressure is increased from there to the engagement hydraulic pressure. Therefore, conventionally, when a shift from the 4th speed to the 2nd speed is performed, the shift becomes a sequential shift, and the drive force change occurs twice as shown by the broken line near the 3rd synchronous rotation speed in FIG.

  On the other hand, in this embodiment, the speed-up time until the standby state of the brake B1, which is the frictional engagement element on the engagement side, is shortened at the time of the next shift, so that the shift instruction is issued when the execution condition for the next shift is satisfied. The signal output can be output without delay. As a result, the delay of the start of the next shift is prevented, and a change in driving force is substantially realized by approximating one shift from the fourth speed to the second speed indicated by a two-dot chain line in the vicinity of the 3rd synchronous rotation speed in FIG. Therefore, the response of the driving force to the operation of the driver can be improved.

  In this embodiment, when the prediction of the next shift is maintained and the execution condition for the next shift is satisfied, one friction engagement element, for example, the brake B1 is engaged from the standby state. If the prediction of the next shift is no longer maintained after the standby hydraulic pressure is supplied to the brake B1, the standby hydraulic pressure supplied to the brake B1 is drained, and therefore the unnecessary standby hydraulic pressure may cause the brake B1 to be rubbed. This prevents future increases in oil temperature and deterioration of friction materials.

  Further, the shift prediction unit 31 has a first time during which the accelerator opening continues to increase due to the accelerator operation, and a second time during which the driving state of the vehicle changes in a direction approaching the down line on the shift diagram. Based on at least one of the above times, it is predicted that the power-on downshift by the clutch-to-clutch shift will be required as the next shift, so that the state where the next shift is predicted can be accurately detected. .

Further, when the ECU 30 predicts that the power-on downshift by the clutch-to-clutch shift is predicted as the next shift by the shift prediction unit 31 during execution of the current shift, the prediction until the output of the shift instruction signal for the next shift is performed. A predicted standby time calculation unit 35 that calculates the standby time Tpr every first predetermined time is provided, and the predicted standby time Tpr is determined from the pressure increase time until the standby state immediately before the engagement of the friction engagement element on the engagement side of the next shift is started. when the became shorter by a second predetermined time, the standby hydraulic pressure supply control unit 32 supplies a standby hydraulic pressure to the frictional engagement element on the engagement side to perform the next gear shift, the frictional engagement during shift instruction signal output of the next shift The element can be brought to a standby state just before the start of engagement. In addition, it is possible to prevent the frictional engagement element from being excessively rubbed due to unnecessary standby hydraulic pressure, leading to an increase in oil temperature and deterioration of the friction material.

  Further, the predicted standby time calculation unit 35 obtains the vehicle speed difference between the current vehicle speed on the shift map and the vehicle speed when reaching the down line that passes when decelerating from the current vehicle speed, and the G sensor 42. Based on the deceleration of the vehicle, the estimated waiting time Tpr is calculated, or at least one is passed when the accelerator opening is increased from the current accelerator opening on the shift diagram and the current accelerator opening. Since the estimated standby time is calculated based on the accelerator opening difference between the accelerator openings when reaching one down line and the amount of change in the accelerator opening per unit time of the vehicle, the predicted standby time Tpr is It can be calculated accurately.

  In the above-described embodiment, the shift prediction unit 31 of the ECU 30 predicts the next shift for the current shift stage. However, the shift prediction unit 31 predicts the next shift for the current shift stage and the next shift ( The prediction of the next shift of the next shift) may be performed.

That is, the shift prediction unit 31 predicts that the current shift stage, for example, a power-on downshift from the 4th speed to the 2nd shift is required as the next shift and the subsequent shift based on the accelerator operation and the driving state of the vehicle. At the same time, the predicted standby time calculation unit 35 shifts the first predicted standby time (Tpr1 in FIG. 7) until the output of the shift instruction signal for the next shift, for example, the shift from the 4th speed to the 3rd speed. The second predicted waiting time (Tpr2 in FIG. 7) until the output of the shift instruction signal for the first shift is calculated for each first predetermined time , and the second predicted waiting time is calculated from the boost time Tc2 for the next shift. When Tpr is shortened by a predetermined time, for example, a second predetermined time , the standby hydraulic pressure may be supplied to the engagement side frictional engagement element that executes the next shift, for example, the brake B1.

  In this case, when downshifting to two or more shift stages, the disengagement friction engagement element, for example, the release timing at the next shift of the clutch C0, the shift after the shift prediction and the change in the driving state, etc. are considered. In addition, it is possible to set the engagement start time of the brake B1, which is an engagement side frictional engagement element that performs the next shift, to a more suitable timing, and to perform the prediction maintenance determination from an early stage to predict the accuracy of the subsequent shift. Can also be increased. As a result, even if the shift time is short, there is no need to delay the output of the shift instruction signal as in the prior art, and a downshift to a shift stage two or more steps away can be executed with high response while preventing a shift shock. Thus, it is possible to provide a control device for an automatic transmission that improves the response of the driving force to the accelerator operation.

  Further, the next shift and the subsequent shift are predicted when the rate of increase of the accelerator opening per unit time is a predetermined value or more, or a kickdown sensor (not shown) is turned ON (the accelerator opening is maximum). It can also be made only at the time of a rapid acceleration request operation such as in the case of. Furthermore, although the standby hydraulic pressure is shown as a constant hydraulic pressure in FIG. 7, it may be considered that the standby hydraulic pressure is gradually increased or dithered until the standby pressure is reached.

  In the above-described embodiment, the automatic transmission 12 does not include a sub-transmission. However, the present invention relates to a sub-transmission in which the automatic transmission is connected to a main transmission unit and its front stage or rear stage. The present invention can also be applied to the case where a power-on downshift of the clutch-to-clutch is executed in the automatic transmission.

  As described above, according to the present invention, when a power-on downshift due to clutch-to-clutch shift is predicted as the next shift, the standby immediately before the start of engagement is established in advance in the friction engagement element on the engagement side of the next shift. Even if the time until the next shift is short, the hydraulic pressure is supplied, and the pressure increase time until the standby hydraulic pressure is shortened, so that the execution condition for the next shift is satisfied and the frictional engagement on the engagement side when the shift instruction signal is output Since the elements can be immediately engaged from the standby state, there is no need to delay the output of the shift instruction signal as in the prior art, and it is possible to downshift to a shift stage that is two or more steps away while preventing a shift shock. It is possible to provide a control device for an automatic transmission that can be executed with a high response and enhance the responsiveness of the driving force to the accelerator operation. Machine control device is particularly useful for the control device in general for an automatic transmission so as to achieve both responsiveness secured on the reduction of shift shock and sudden acceleration request.

FIG. 1 is an overall block diagram showing an automatic transmission control apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of an automatic transmission and its control device according to an embodiment of the present invention. FIG. 3 is a diagram showing an engagement logic table of the automatic transmission according to the embodiment of the present invention. FIG. 4 is a shift map of the automatic transmission according to one embodiment of the present invention that is converted into a constant map. FIG. 5 is a schematic cross-sectional view of a friction engagement element according to an embodiment of the present invention. FIG. 6 is a flowchart of the shift control executed by the automatic transmission control apparatus according to the embodiment of the present invention. FIG. 7 shows changes in the input rotational speed of the gear transmission mechanism when a two-stage shift is executed from the fourth speed to the third speed and further to the second speed in the automatic transmission according to the embodiment of the present invention. It is a timing chart which shows the change of the engagement oil pressure of the friction engagement element of the engagement side of a gear stage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Engine 11a Output shaft 12 Automatic transmission 14 Torque converter 15 Gear transmission mechanism 15h Transmission case 16 Hydraulic control device 17 1st planetary gear 18 2nd planetary gear 19 Oil pump 21 Accelerator opening sensor 22 Throttle opening sensor 23 Water temperature sensor 24 Suction Air amount sensor 25 Engine speed sensor 26 Brake pedal sensor 27 Shift position sensor 28 Turbine speed sensor 29 Vehicle speed sensor 30 ECU (electronic control unit)
31 Shift prediction unit (shift prediction means)
32 standby hydraulic pressure supply control unit (standby hydraulic pressure supply means)
33 Engagement hydraulic control unit (engagement hydraulic control means)
34 Prediction maintenance determination unit (prediction maintenance determination means)
35 Predicted standby time calculation unit (predicted standby time calculation means)
41 Gradient sensor 42 G sensor 50 Hydraulic multi-plate clutch 51 One rotation or fixed element 55 The other rotation or fixed element 52, 56 Friction plate 57 Piston 58 Return spring 61a, 61b, 61c, 61d, 61e Electromagnetic drive part 62a, 62b , 62c, 62d, 62e Control valve portion 63 Modulator valve 64 Manual valve B1 Brake (Friction engagement element on one side, standby hydraulic pressure supply means)
B2 Brake (Standby hydraulic pressure supply means)
C0, C1 clutch (standby hydraulic pressure supply means)
C2 clutch (frictional engagement element on one side, standby hydraulic pressure supply means)
Cr1, Cr2 carrier D21, D32, D43 Down line F1 Low one-way clutch Ia, Ib, Ic, Id, Ie Indication current (shift control signal)
L1 D range oil path L2 R range oil path M1 1st rotation shaft M2 2nd rotation shaft Min Transmission input shaft Mout Transmission output shaft P1, P2 Pinion R1, R2 Ring gear S1, S2 Sun gear Tc1, Tc2 Boost time Tpr Prediction standby Time Tpr1 First predicted waiting time Tpr2 Second predicted waiting time

Claims (6)

In a control device for an automatic transmission for executing a shift control by outputting a shift instruction signal for selectively engaging and releasing a plurality of hydraulic friction engagement elements of the automatic transmission according to an accelerator operation and a driving state of the vehicle ,
It is predicted that a power-on downshift by clutch-to-clutch shift with the engagement of one friction engagement element and the release of the other friction engagement element among the plurality of friction engagement elements will be required as the next shift. Shift prediction means for
When a power-on downshift due to the clutch-to-clutch shift is predicted as the next shift by the shift prediction means, the standby immediately before starting the engagement with the one friction engagement element that executes the next shift Standby hydraulic pressure supply means for supplying hydraulic pressure for making a state;
Engagement hydraulic control that outputs the shift instruction signal and engages one of the friction engagement elements from the standby state when a condition for executing the next shift is established according to the accelerator operation and the driving state of the vehicle Means,
It is determined at predetermined time intervals whether or not the prediction of the next shift by the shift prediction unit is maintained when the standby hydraulic pressure supply unit supplies the one frictional engagement element with the hydraulic pressure for setting the standby state. Predictive maintenance determining means for
When it is determined by the prediction maintenance determination means that the prediction of the next shift is maintained, and when the condition for executing the next shift is satisfied according to the accelerator operation and the driving state of the vehicle, Engaging the friction engagement element from the standby state;
When the prediction maintenance determination means determines that the prediction of the next shift is not maintained, the standby hydraulic pressure supply means supplies the hydraulic pressure for setting the standby state supplied to the one friction engagement element. A control device for an automatic transmission characterized by draining . The shift predicting means changes in a direction in which the accelerator opening continues to increase due to the accelerator operation and the driving state of the vehicle approaches a down line on the shift diagram of the automatic transmission. The power-on downshift by the clutch-to-clutch shift is predicted to be required as the next shift based on at least one of the second times. Automatic transmission control device. When a power-on downshift due to the clutch-to-clutch shift is predicted as the next shift by the shift prediction means while the current shift is being executed according to the accelerator operation and the driving state of the vehicle, the next shift An estimated waiting time calculating means for calculating an estimated waiting time until the output of the shift instruction signal for shifting, every first predetermined time;
When the predicted standby time is shorter by a second predetermined time than the pressure increase time required for the one friction engagement element to be in a standby state immediately before the start of the engagement, the standby hydraulic pressure supply means performs the next shift. The control apparatus for an automatic transmission according to claim 1 or 2 , wherein a hydraulic pressure for setting the standby state is supplied to the one friction engagement element that performs the operation . The predicted waiting time calculating means is a vehicle speed difference between a current vehicle speed on a shift diagram of the automatic transmission and a vehicle speed when reaching a down line that passes when decelerating from the current vehicle speed; 4. The control device for an automatic transmission according to claim 3, wherein the predicted standby time is calculated based on the deceleration . When the predicted waiting time calculation means reaches the current accelerator opening on the shift diagram of the automatic transmission and at least one down line that passes when the accelerator opening increases from the current accelerator opening. 5. The predicted waiting time is calculated based on an accelerator opening difference between accelerator openings and an amount of change in the accelerator opening per unit time of the vehicle. 6. Control device for automatic transmission. The shift prediction means predicts that the power-on downshift of two or more stages from the current shift stage is required as the next shift and the subsequent shift based on the accelerator operation and the driving state of the vehicle,
The predicted standby time calculation means includes a first predicted standby time until output of the shift instruction signal for the next shift, and a second predicted standby time until output of the shift instruction signal for the next shift. And calculate
When the second predicted standby time is shortened by a predetermined time from the pressure increase time for the next shift, a hydraulic pressure for setting the standby state is supplied to one friction engagement element that performs the next shift. The control device for an automatic transmission according to any one of claims 3 to 5, wherein: