JP2878285B2 - Transmission control device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shift control device for an automatic transmission.

(Prior Art) In recent vehicles, an automatic transmission is often used as a transmission. The automatic transmission generally includes a torque converter, and a multi-stage transmission gear mechanism of a planetary gear type that performs a speed change by using a turbine speed of the torque converter as an input speed. The power transmission path of the multi-stage transmission gear mechanism is switched, that is, the speed is changed, by appropriately engaging or releasing a plurality of frictional engagement elements such as a brake and a clutch attached to the multi-stage transmission gear mechanism. .

On the other hand, in a vehicle with an automatic transmission, a problem is how to reduce a shock during shifting, that is, a shifting shock. It is known that the operation switching of the friction engagement element described above may be performed slowly to reduce the shift shock. However, switching the operation of the frictional engagement element too slowly is problematic in terms of securing the durability of the frictional engagement element, in addition to increasing the shift time.

From such a viewpoint, an optimal target shift time is set in advance, and the operating oil pressure (engagement of the friction engagement element during shifting) is set so that the actual shift time required for the actual shift matches the target shift time. It has also been proposed to correct the magnitude of the hydraulic pressure or the release hydraulic pressure
No. 56-10851).

(Problems to be Solved by the Invention) By the way, it has been considered that at the time of shifting, the turbine speed is changed at a predetermined change rate so that the shifting is smoothly performed. In this case, the change rate of the turbine speed can be changed at a predetermined setting time that is optimal for the shift and the change rate of the turbine speed according to the change of the speed ratio (gear ratio before and after the shift). Basically, it can be determined whether or not to do so.

In order to control the above-described turbine rotation speed to change at a predetermined change rate, it is necessary to detect the actual turbine rotation speed and change the turbine rotation speed at a predetermined target change rate, that is, the target change rate. It is advantageous to perform feedback control so as to achieve the target turbine speed corresponding to

On the other hand, depending on the mode of shifting, the two frictional engagement elements may be switched in operation. In this case, when the feedback control is performed on the engagement forces of the two friction engagement elements so as to have the above-described target change rates, both feedback controls interfere with each other, and the shift is not performed smoothly. Therefore, at the time of such a shift, it is conceivable that both of the friction engagement elements perform feedforward control, that is, a kind of prospective control, such that the turbine speed becomes a predetermined target change rate. However, in this case, although control interference can be prevented, it is difficult to change the turbine speed at a desired rate of change due to the limit of the feedforward control. Becomes difficult.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a shift control device for an automatic transmission, which can effectively prevent a shift shock when two frictional engagement elements are switched in operation.

(Means and Actions for Solving the Problems) In order to achieve the above object, the present invention has the following configuration. That is, FIG. 22, that is, FIG.
As shown in the block diagram in the figure, a torque converter, and a multi-stage transmission gear mechanism that performs a speed change by using the turbine speed of the torque converter as an input speed are provided. In the automatic transmission configured to perform a shift of the multi-speed transmission gear mechanism, a first engagement force adjusting unit that adjusts a magnitude of an engagement force of a first friction engagement element among the friction engagement elements; Second fastening force adjusting means for adjusting the magnitude of the fastening force of the second frictional fastening element, rotation speed detecting means for detecting the turbine speed, the first fastening force adjusting means and the second fastening force adjustment Control means for controlling the means, wherein the control means performs a predetermined gear shift when the engagement states of the first frictional engagement element and the second frictional engagement element change in opposite directions, and While the change in the turbine speed is occurring, the first fastening force adjusting unit is feedback-controlled so that the turbine speed detected by the speed detecting unit approaches a preset target speed. The second frictional engagement element is set so as to be feed-forward controlled such that the coupling force of the second frictional coupling element changes at a predetermined rate of change, and is further set so as to correct the predetermined rate of change. The correction of the predetermined change rate is performed for each predetermined control cycle obtained based on the actual change rate of the turbine rotation speed obtained based on the turbine rotation speed detected by the rotation speed detection means and the target rotation speed. This is performed based on the deviation from the target turbine speed change rate.

The correction of the predetermined change rate can be specifically performed as follows. That is, assuming that the predetermined shift time is an upshift, the correction is made so that the predetermined change rate becomes smaller as the actual change rate of the turbine speed is larger than the target turbine speed change rate by a predetermined value or more. You.
Further, the correction is made such that the predetermined change rate becomes larger as the actual change rate of the turbine speed is smaller than the target turbine speed change rate by a predetermined value or more.

(Effects of the Invention) According to the present invention, even during a shift in which the operation switching of the two frictional engagement elements is performed together, the control during such a shift is optimized and the shift is smoothly performed. Can be. In particular, since a predetermined change rate in the case of the feedforward control is corrected according to the progress of the shift,
The feedforward control is optimized, and the shift can be performed more smoothly.

Of course, any one of the two frictional engagement elements can be selected as an object to be subjected to feedback control, so that feedback is performed for each shift mode (shift from first gear to second gear, shift from second gear to third gear, etc.). The frictional engagement element on the side to be controlled (or feedforward control) may be determined in advance, and such setting makes it possible to more effectively prevent shift shock.

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

FIG. 1 is a skeleton view schematically showing an automatic transmission in which a hydraulic control device of the present invention is incorporated.

In FIG. 1, reference numeral 1 denotes a crankshaft of an engine (not shown) which is an input shaft, and a torque converter 2 and a multi-stage transmission 10 are arranged coaxially with the crankshaft 1 from the engine side. . The torque converter 2 includes a pump 3, a turbine 4, and a stator 5, and the pump 3 is fixed to the crankshaft 1. The stator 5 rotates via a one-way clutch 6 on a fixed shaft 7 integrated with a case 11 of the multi-speed transmission 10. The one-way clutch 6 allows the stator 5 to rotate in the same direction as the pump 3 but does not allow reverse rotation.

The multi-stage transmission gear device 10 has a base end fixed to the crankshaft 1 and a front end extending through the center of the multi-stage transmission gear device to drive an oil pump P disposed on a side wall of the multi-stage transmission gear device. It has a central shaft 12 connected to a pump.
Outside the center shaft 12, a base end is connected to the turbine 4 of the torque converter 2, and a front end extends to the side wall of the multi-stage transmission 10 and is a hollow turbine rotatably supported on the side wall. A shaft 13 is provided. A Ravigneaux-type planetary gear unit 14 is provided on the turbine shaft 13. It comprises a long pinion gear 17, a short pinion gear 18, and a ring gear 19.

Forward and coast clutches 20, 21 are arranged side by side on the side of the planetary gear unit 14 farther from the engine. Forward clutch 20 above
Is a clutch for traveling forward, which interrupts power transmission between the small-diameter sun gear 15 and the turbine shaft 13 via the first one-way clutch 22. The coast clutch 21 interrupts power transmission between the small-diameter sun gear 15 and the turbine shaft 13 in parallel with the forward clutch 20. A 2-4 brake 23 is disposed radially outward of the coast clutch 21. The 2-4 brake 23 is a band brake, and has a brake drum 23-1 connected to the large-diameter sun gear 16 and a brake band 23-2 applied to the brake drum. A reverse clutch 24 is disposed radially outward of the forward clutch 20 and beside the 2-4 brake 23. This reverse clutch 24
Is a clutch for reverse running, and the above 2-4 brake
The large-diameter sun gear 16 is passed through the 23 brake drum 23-1.
And intermittent power transmission between the turbine shaft 13.

Outside the planetary gear unit 14 in the radial direction,
A low / reverse brake 25 for disengaging the carrier 14a of the planetary gear unit 14 and the case 10a of the multi-speed transmission 10 is arranged. A second one-way clutch 26 for disengaging the carrier 14a and the case 10a in parallel with the low reverse brake 25 is disposed between the brakes 23 and 25 between the above 2-4 and the low reverse. .
A 3-4 clutch 27 for interrupting power transmission between the carrier 14a of the planetary gear unit and the turbine shaft 13 is disposed on the side of the planetary gear unit 14 on the engine side. An output gear 28 connected to the ring gear 19 is arranged on the engine side of the 3-4 clutch 27, and the gear 28 is attached to an output shaft 28a. It should be noted that reference numeral 29 in FIG.
Denotes a lock-up clutch for directly connecting the turbine shaft 13 and the crankshaft 1 without passing through the torque converter 2.

Function of the multi-stage transmission gear device 10 The multi-stage transmission gear device 10 having the structure described above has four forward speed stages and one reverse speed stage by itself, and each clutch 20,
By appropriately operating the brakes 21, 24 and 27 and the brakes 23 and 25, a required gear can be obtained. Table 1 below shows the relationship between the gears and the operation of the clutch and brake in the above configuration. Of the clutches and brakes, only the 2-4 brake 23 (actuator) has two oil chambers, an apply side and a release side, as described later, to supply hydraulic pressure to the apply side and release the oil. Only when the hydraulic pressure on the side is released, the 2-4 brake 23 is engaged, and in other hydraulic supply modes, the 2-4 brake 23 is released. The remaining clutches and brakes (each actuator) have only one oil chamber, and are engaged when hydraulic pressure is supplied to the oil chamber, and when the hydraulic pressure in the oil chamber is released. Open to the public.

Hydraulic Circuit (Overview) Next, the hydraulic circuit for the automatic transmission shown in FIG. 1 will be described with reference to FIG.

Manual Valve 41 in FIG. 2 is a manual valve (hereinafter referred to as MB).
As is known, by manual operation, P, R, N,
D, two, and one of six range positions can be taken. The MB 41 has ports a, c, e, f, and g. The hydraulic pressure pumped from the reservoir tank 42 by the pump P is regulated by a pressure regulator valve (hereinafter referred to as PRV) 43 connected to the oil passage 101, and a line g is supplied to a port g. The other ports a, c, e, and f that communicate with the range position of the MB 41 and the port g to which the line pressure is supplied are as follows.

P range: No port to be connected R range: Only port f N range: No port to be connected D range: Port a and c 2 range: Port a and c 1 range: Port a and e Duty solenoid valve On the other hand, the pump The hydraulic pressure pumped by the P is reduced to a predetermined pressure by a solenoid reducing valve 44 through an oil passage 102, and the reduced hydraulic pressure is reduced to first to fourth duty solenoids (hereinafter referred to as DSL) 45.
Adjusted by A, 45B, 45C, 45D. The hydraulic pressure adjusted by the first DSL 45A is supplied through the oil passage 103 as the pilot pressure of the PRV 43. The oil pressure adjusted by the second DSL 45B is supplied as a pilot pressure of a 3-4 pressure control valve (hereinafter, referred to as 3-4PCV) 46 via an oil passage 104, and an oil passage branched from the oil passage 104. It is supplied as a pilot pressure of a reverse pressure control valve (hereinafter referred to as RPCV) 47 via 104a. Hydraulic pressure regulated by the third DSL45C passes through the oil passage 105, and then to a servo pressure control valve (hereinafter referred to as SPCV).
Supplied as a pilot pressure of 48. The hydraulic pressure adjusted by the fourth DSL 45D is supplied as the pilot pressure of the lock-up control valve 49 via the oil passage 106.

Here, the SPCV 48 adjusts the hydraulic pressure on the release side of the 2-4 brake actuator 23A, which will be described later, via the oil passage 138. After 107, it is supplied as pilot pressure of a coast control valve (hereinafter referred to as CCV) 50. Therefore, the third DSL45C is used for both the pilot pressure adjustment of the SPCV48 itself and the pilot pressure adjustment of the CCV50. Further, the regulated hydraulic pressure on the release side is also used as a forward clutch pressure which is switched by a forward control valve (hereinafter referred to as FCV) 51 through an oil passage 107a branched from the oil passage 107 as described later. It has become.

Clutch and brake actuators Among the gear shift clutches and brake actuation actuators, except for the 2-4 brake actuator 23A, the other actuators are of the type that are simply engaged when hydraulic pressure is supplied. The actuator in the figure is shown using the reference numerals assigned to the clutch and the brake as they are.

The 2-4 brake actuator 23A is as follows. That is, the inside of the cylinder 23a is
Is defined by an apply-side oil chamber 23c and a release-side oil chamber 23d.
The piston rod 23e connected to 3-2 is integrated. The piston 23b is urged downward in FIG. 2 by a spring 23f. And this actuator 23
In A, the 2-4 brake 23 is engaged only when the condition that the line pressure is supplied to the apply-side oil chamber 23a and the oil pressure of the release-side oil chamber 23d is released. In other words, even when the line pressure is supplied to the apply-side oil chamber 23c, when the line pressure is supplied to the release-side oil chamber 23d, the 2-4 brake 23 is released, and the release-side oil chamber 23c is released. 23d oil pressure regulated by SPCV48 (3DSL45C
), The engagement force of the 2-4 brake 23 is adjusted.

Connection Relationship between Manual Valve (MB) 41 and Each Friction Element (Actuator) The forward clutch 20 is connected to a port a of the MB 41 via an oil passage 121, the FCV 51, and oil passages 122 and 137.

Coast clutch 21 (actuator) is in the oil passage
123, the CCV 50, an oil passage 124, a coast exhaust valve (hereinafter referred to as CEV) 52 as a switching valve, an oil passage 125,
After 127, it is connected to port a.

3-4 clutch 27 (actuator) 27 is an oil passage
128, the 3-4PCV 46, the oil passage 129, the 2-3 shift valve (hereinafter referred to as SV) 54, and the oil passage 130, and are connected to the port c.

Low reverse brake (actuator for 25)
The oil passage 131 is connected to the port f via the switching valve 55. Also, the oil passage 132, 1-2SV56,
The oil passage 133 is connected to a port e via a low reducing valve (hereinafter referred to as LRV) 57.

The reverse clutch (actuator) 24 is an oil passage
134, the RPCV 47 and the oil passage 135 are connected to the port f.

The apply-side oil chamber 23c of the 2-4 brake actuator 23A is connected to the port a via the oil passages 136, 1-2SV56, and the oil passage 137. Also, the oil chamber 23d on the release side
Through the oil passage 138, the SPCV48, the oil passages 139 and 137,
It is connected to port a. The pressure in the release-side oil chamber 23d is increased by the oil passage 138 and the oil passage 107
It is supplied to FCV51 and CCV50 using 107a.

Shifting of shift valves (SV) 54, 56 The supply and release of the pilot pressure of the 2-3SV 54 is controlled by a 2-3 solenoid (hereinafter referred to as SL) 58 which is turned on and off. The pilot pressure regulated by the 2-3SL58 is the oil passage 13 extending from the port a of the MB41.
Oil pressure (pilot pressure) from oil passage 137a branched from 7
Is directly supplied to the 2-3SV 54 or drained. When the 2-3SL 58 is turned on, the drain is generated.

In the 1-2SV56, the supply and release of the pilot pressure are controlled by the 1-2SL59. As the pilot pressure controlled by the 1-2SL59, the line pressure from the oil passage 140 bypassing the MB41 is used, and the pilot pressure is drained when the 1-2SL59 is turned on (the pilot pressure is released). This 1-2SV56
The pilot pressure for use also includes the pilot pressure controlled by the 2-3SV54. That is, 2-3SL5
The pilot pressure controlled by 8
Also acts as V56 pilot pressure. These both SL58 and 59
The operation of the 1-2SV56 by both pilot pressures is as follows. First, assuming that the pilot pressure controlled by the 2-3SL58 is zero (2-3SL58 is turned on and drained), 1-2SL59 is turned off (the pilot pressure becomes the line pressure), whereby 1- The 2SV 56 is displaced to the left in the figure to make the oil passages 137 and 136 communicate with each other (line pressure is supplied to the apply side oil chamber 23c of the 2-4 brake actuator 23A). On the other hand, 2-3SL58 turns off and
If the pilot pressure for -3SV54 is the line pressure,
This line pressure is used as the pilot pressure for the 1-2SV56, regardless of whether the 1-2SL59 is on or off.
Is displaced rightward in the figure (the oil passages 137 and 136 are shut off).

As the pilot pressure of the coast exhaust valve (CEV) 52 CEV 52, the pilot pressure controlled by the 1-2SL59 is used as it is. That is, the pilot pressure controlled by the 1-2SL59 is supplied as the pilot pressure of the CEV 52 via the oil passage 142. For CEV52 as this switching valve,
The original pressure (line pressure) from the port e, which is generated only when the select valve 41 is in one range, is supplied as the pilot pressure via the oil passage 127.

As a result, the CEV 52 increases the pilot pressure controlled by the shift solenoid 59 for the 1-2 shift valve 56 at the 2nd speed of the D range, 3rd speed, 2nd speed of the 2nd range, 3rd speed and 2nd speed of the 1st range. Receiving the coast clutch
The state is switched to a state in which hydraulic pressure for fastening 21 can be supplied. In addition to this, the CEV52 is
The source pressure from port e is received as pilot pressure, and the state is switched to a state in which hydraulic pressure for engaging coast clutch 21 can be supplied.

The relationship between ON / OFF of the solenoid valves (SL) 58, 59 and each gear is shown in Table 2 below. In the fourth speed, both solenoid valves 58 and 59 can be turned off.

Lock-Up Clutch 29 As is known, the lock-up clutch 29 is normally engaged by receiving the pressure in the torque converter 2 and is disconnected when hydraulic pressure is supplied to the lock-up clutch 29. The lock-up clutch 29 is connected to the line pressure passage 101 that bypasses the MB 41 via the oil passage 151, the lock-up control valve 49, and the oil passage 152. Thus, by controlling the pilot pressure of the lock-up control valve 49 by the fourth DSL 106, the on / off state of the lock-up clutch 29 and the state of the half-clutch are controlled.

Torque converter 2 The torque converter 2 is connected to the lock-up control valve 49 via an oil passage 153. And
A converter relief valve 60 is connected to the oil passage 152 connected to the lock-up control valve 49, so that the pressure (oil passage 152) in the torque converter is always kept constant.

Details of the operation of various valves and the like in the hydraulic circuit Shift (shift valve) The shift in each range of D, 1, 2 is basically
It is obtained by appropriately turning on and off the shift SLs 58 and 59 as shown in Table 2 above. Specifically, 1-2S
By controlling the hydraulic pressure supply / discharge to / from the apply side oil chamber 23c by V56 (1-2SL59) and the hydraulic pressure supply / discharge to the release side oil chamber 23d by the third DSL45C, the engagement and release of the 2-4 brake 23 Control is performed as shown in Table 1.

Further, by controlling the hydraulic pressure supply / discharge to the 3-4 clutch 27 by the 2-3SV54 (2-3SL58), the engagement and release of the 3-4 clutch 27 are controlled as shown in Table 1.

Low reducing valve (LRV) 57 Adjusts the pressure so that the engagement pressure of low / reverse brake 25 in one range is kept at a low constant pressure.

Reverse pressure control valve (RPCV) 47 When selecting from the N range to the D range, the pilot pressure is adjusted by the second DSL45B and the reverse clutch 2
Adjust the fastening pressure of 4 to reduce the shock at the time of this selection.

Coast control valve (CCV) 50 This is to ensure that the coast clutch 21 is released at the 4th speed. The pilot pressure of CCV50 is 2-4
In addition to the oil pressure in the release-side oil chamber 23d of the brake actuator 23A, an oil pressure for engaging the 3-4 clutch 27 is used via an oil passage 143. Thereby, 3-
At the 4th speed when the 4 clutch 27 is engaged and the 2-4 brake 23 is engaged, since the pressure in the release side oil chamber 23d of the 2-4 brake actuator 23A is released, the 3-4 clutch 27 Under the fastening pressure, CCV50
The engagement hydraulic pressure of the coast clutch 21 is released. This is because the planetary gear unit 14 is locked internally when the 3-4 clutch 27 and the 2-4 brake 21 are engaged, and this is done to prevent this internal locking. As described above, since the hydraulic pressure indicating the engaged state of the 3-4 clutch 27 and the 2-4 brake 23 is directly used as the pilot pressure of the CCV 50, the occurrence of the internal lock at the fourth speed is reliably prevented. Is done. This means that when the shift SL58 and 59 are both turned off at the 4th speed,
By the stick of the coast exhaust valve 52, etc.
In the case where the shift signal and the actual hydraulic pressure supply mode are different from each other, the fail-safe function for reliably preventing the internal lock is effective.

As described above, the coast exhaust valve (CEV) 52 is controlled by the pilot pressure controlled by the 1-2SL59 and the base pressure as the pilot pressure from the port e, and performs the basic engagement and release of the coast clutch 27. (See Tables 1 and 2).

The CEV 52 may temporarily cause the above-described internal lock depending on the operation timing of the 3-4 clutch 27 and the 2-4 brake 23 when shifting from the second speed to the third speed. Internal lock is reliably prevented. That is, first, the 2-3SL58 is turned off (to be a line pressure as the pilot pressure), and the 1-2S
The V56 is fixed to the second speed side, and then the CEV 52 is set to the drain side by the pilot pressure (line pressure) of 1-2SL59, and the hydraulic pressure for engaging the coast clutch 21 is released. Of course, such an operation is performed only during the shift, and the coast 21 is re-engaged after the shift to the third speed is completed.

Forward control valve (FCV) 51 When shifting from the N range to the D range, the SPCV 48 is controlled by the third DSL 45C to adjust the oil pressure of the oil passage 107 (107a). When the oil passage 107a is lower than the predetermined pressure, the FCV 51
Supplies a hydraulic pressure less than the predetermined pressure to the forward clutch 20, and supplies the line pressure from the oil passage 122 to the forward clutch 20 as it is when the hydraulic pressure of 107a becomes a predetermined pressure or more.
In this way, the shock at the time of shifting from the N range to the D range is reduced.

3-Pressure control valve (3-4PCV) 46 At the time of shifting, receiving the adjustment of the pilot pressure by the second DSL 45B, the engagement force of the 3-4 clutch 27 is adjusted (shift shock prevention).

Servo pressure control valve (SPCV) 48 The pilot pressure is controlled by 3DSL45C.
The pressure of the release-side oil chamber 23d of the 4 brake 23 is adjusted (prevention of shift shock) and the engagement pressure of the forward clutch 20 is adjusted (see the description of the FCV 51).

At the time of shifting from the first gear to the second gear, the fastening hydraulic pressure is supplied to the apply-side oil chamber 23c by the 1-2SV56.
At this time, the shift shock is reduced by adjusting the pressure in the release-side oil chamber 23d.

At the time of shifting from the second speed to the third speed, the opening hydraulic pressure is finally supplied to the release-side oil chamber 23d while adjusting the pressure of the release-side oil chamber 23d while taking the timing of engaging the 3-4 clutch 27 ( Shift shock prevention). That is, in both the second speed and the third speed, the engagement hydraulic pressure is supplied to the apply-side oil chamber 23c. However, by switching between the supply and release of the hydraulic pressure to the release-side oil chamber 23d, the engagement of the 2-4 brake 23 is performed. The shift is switched between open and open, and the hydraulic pressure supplied to the release-side oil chamber 23d is adjusted by the SPCV 48, thereby preventing a shift shock (2-4 brake 23 is slowly engaged).

At the time of shifting from the third speed to the second speed, while adjusting the pressure of the release side oil chamber 23d while taking the timing of releasing the 3-4 clutch 27, the hydraulic pressure of the release side oil chamber 23d is finally released ( 2-4 Application of brake 23).

Next, the control at the time of shifting will be described. At the time of this shift, the first and second gears are used to prevent a gear shift shock.
By adjusting the engagement force between the 2-4 brake 23 and the 3-4 clutch 27 by the DSL 45B and 45C, more specifically, by controlling the duty of both the DSL 45B and 45C, the turbine speed is changed at a predetermined rate. Is controlled to change.

The control during gear shifting is performed by a control unit U using a microcomputer. While signals from the sensors 211 to 214 are input to the control unit U, the signals are output from the control unit U to at least the DSLs 45B and 45C. The sensor 211 detects the throttle opening. The sensor 212 detects a vehicle speed. The sensor 213 detects the turbine speed. The sensor 214 detects the oil temperature. The control unit U basically includes a CPU, a ROM, a RAM, and a CLOCK, and further includes an input / output interface, an A / D converter, and the like. However, since these are known configurations using a microcomputer, Further description is omitted.

Overall Overview The shift control is roughly divided into a first area (control area), a second area (control area), and a third area (control area) sequentially from the start of the shift as shown in FIG. You. In addition,
The shift mode described below refers to a shift between any two shift speeds among the first to fourth shift speeds.
A shift from the second speed to the second speed, a shift from the first speed to the third speed, and the like.

The first area is an area in which a change in turbine speed hardly occurs due to the relationship between the play of the brake and the clutch, etc., and is an area in which gear shifting is actually prepared.
In this case, DSL45B and 45C (duty ratio to)
Is feed-forward controlled for a predetermined set time.

The second region is a speed change region in which the turbine speed is greatly changed, and is a region to be controlled by the present invention. In the second area, a predetermined set time is set, and a plurality of control cycles obtained by equally dividing the set time are set. In each control cycle, the DSL 45B and 45C are feedback-controlled in principle. However, at the time of gear shifting in which both the 2-4 brake 23 and the 3-4 clutch 27 are switched, the one of the DSLs 45B and 45C is feedback-controlled and the other is feed-forward controlled. This is to prevent mutual interference between the two DSLs 45B and 45C when feedback control is performed. Therefore, of the two DSLs 45B and 45C, the DSL for which feedback control is more advantageous in preventing shift shock is determined in advance according to the shift mode.

The third area is an area where post-processing of the shift is performed. In the third area, the duty control for preventing the shift shock is no longer required for the DSL 45B and 45C, and the duty ratio is maintained at 0% or 100% according to the operation relationship as shown in Table 2. (ON or OFF). In the third area, a process for obtaining a learning value is also performed because learning control is performed between the first area and the second area.

Predetermined set time t _T carried out in detail the first region of the control in the first region, it is so varied in accordance with the throttle opening as shown in Figure 5. As apparent from FIG. 4, because although t _T as the throttle opening is small becomes large, which during operation the throttle opening is small often particularly averse equal shift shock steady running is being performed It is. Further, the setting of t _T is apparent from the reason described later, but is determined in units of 16 msec. Therefore, in actual control, the value of t _T is a coefficient by which 16 msec is multiplied. It is determined (32 msec when t _T = 2). Note that this t
_T uses the same value at the time of shift-up and at the time of shift-down for simplification of control.

Duty ratio by the feedforward control in the first region, and setting a plurality of control cycles obtained by equally dividing the predetermined time t _T every 16 msec, a duty ratio in each control cycle is determined by the following equation (1) .

_{D = D S × C 3 +} ΔD × C 4 (t T -t) × S ··· (1) D: duty ratio D _S of each control cycle: learning value (initial value) [Delta] D: base value t: shift start elapsed time from C _3: correction coefficient C _4: correction coefficient S: factor hydraulic increase or decrease setting the learning value D _S is to be determined in the third region which will be described later. If there is no learning value, an initial value set in advance for each shift mode is used. In addition,
This initial value is set based on when the throttle opening is 50%.

Correction factor C ₃ to correct the D _S is the throttle opening is 1 /
The value of 2 is set as the reference "1", and is gradually increased as the throttle opening becomes smaller than 1/2, and is gradually decreased as the throttle opening becomes larger than 1/2.

The above ΔD indicates a basic gradient of a change in hydraulic pressure, and is determined in advance according to a shift speed. This correction coefficient C ₄ of ΔD to correct, depending on the magnitude of the turbine speed change amount in the first region in, is set as shown in Figure 6. The amount of change in the turbine speed in FIG. 6 is for 16 msec (the amount of change per control cycle). The above S indicates the direction of increase or decrease of the hydraulic pressure,
When increasing the pressure, the value is “+”, and when the pressure is reduced, the value is “−”. Therefore, this S is uniformly determined by the speed before and after the shift.

The duty ratio D determined by the expression (1) is finally corrected according to the oil temperature, and the duty ratio after the oil temperature correction is output to one or both of the DSL 45B and 45C.

The control of the first region as described above is performed by the above-described set time t _T.
Is terminated when elapses.

Details of the control in the second area First, a predetermined set time T for performing the control in the second area
_m is determined using the throttle opening as a parameter, as shown in FIG. The T _m is the same as the control time t _T of the first region mentioned above, is set to 16msec units, in determining the T _m is the coefficient multiplied to the control on 16msec (T _m = 30 of Time is 480msec). For simplicity of control, T _m is are together upshifting and downshifting to use the same value.

−1: Feedback control The feedback control in the second region is performed based on the set time T _m.
The target value is updated in each control cycle in which the target value is equally divided every 16 msec. When this point will be described sequentially, first, turbine speed that will become after the shift is calculated as the target turbine rotational speed N _R. This target turbine speed N
_E is the gear ratio before shifting, and the actual turbine speed N _S of the pre-shift, by a gear ratio after shifting, is proportionally calculated by the following equation (2).

N _E = N _S × gear ratio after shifting / before shifting gear ratio (2) Then, set the actual value obtained by subtracting the turbine rotation speed N _S of the target turbine speed N _E of the pre-shift time T By reducing by _m , the target turbine speed change rate α _m is calculated. That is, α _m = (N _S −N _E ) / T _m (3) Thereafter, the change amount α _m (k) of the target turbine speed for each control cycle is determined by the following equation (4).

α _m (k) = α _m × C ₁ × C ₂ (4) α _m (k): target turbine speed change amount at k-th control cycle C ₁ : correction coefficient C ₂ : correction coefficient C ₁ is the correction according to the elapsed time T from the start of control of the second region is set as shown in FIG. 8.
As apparent from FIG. 8, the region of the beginning and end of the T _m small C _1, also an intermediate region of the T _m C ₁ is increased. As a result, the target turbine rotational speed change amount, that is, the rate of change of the turbine rotational speed, which will be described later, is made larger in a region intermediate _Tm (a region intermediate the second region) than in regions before and after it. . The correction coefficient C ₂ is
It is as deviation of the actual turbine speed and the target turbine speed N _E is greater increases. In Example, C ₂ is the time the deviation is more than 140rpm as "1", deviation are set to be gradually smaller as less than 140rpm.

In each control cycle, the target turbine speed is determined by the following equation (5) so as to achieve the target turbine speed change amount α _m (k) determined as described above.

N (k) = N (k−1) −α _m (k) (5) N (k): Target turbine speed at kth control cycle N (k−1): k−1th control cycle The target turbine rotation speed N (k), which is sequentially determined for each control cycle as described above, shows how the turbine rotation speed changes with the pulse width output to the DSL45B or 45C. This is shown in FIG. In FIG. 9, a direction in which the turbine rotational speed decreases is shown as an example.

-2: Feedforward control In the feedforward control in the second area, the duty ratio is determined for each control cycle based on the following equation (6).

D (k) = D (k−1) + ΔD × C ₅ × S (6) D (k): Duty ratio at control cycle kth D (k−1): Duty at control cycle k−1 Ratio ΔD: slope of change (base value) C ₅ : correction coefficient S: coefficient indicating increase / decrease direction of oil pressure The above D (k) will be described later in the first control cycle (when k = 1). A learning value is used, and when this learning value does not exist, an initial value set in advance for each shift mode is used (see the description of Expression (1)).

The above S is the same as S in the equation (1), and is either “+1” or “−1”. The above ΔD is a basic rate of change in turbine speed, and is determined in advance in accordance with a shift mode (for example, shift from first gear to second gear). The correction coefficient C ₅ is determined by the amount of change turbine speed (in fact would mean change rate indicating a rate of change between 16msec in). More specifically, the correction coefficient C _5, when the shift-down is set to "1" uniformly, based case of upshift only to the amount of change of the turbine rotational speed is calculated based on the following equation (7) Is read from the previously created map.

Turbine rotation speed change amount = (N _k −N _k−1 ) −α _m (k) (7) N _k : Actual turbine rotation speed at the _k- th control cycle N _k−1 : Control cycle k−1 th actual turbine rotational speed alpha _{m (k):} control cycle k-th target turbine speed change amount C ₅ in ((4) reference) upshift is specifically a turbine in the formula (7) The rotation speed change amount is set to "1" during the range of -10 to 10 rpm, gradually increased as the turbine rotation speed change amount increases in the negative direction, and gradually decreased as the turbine rotation speed change amount increases in the positive direction. Is done.

During such feedforward control, 2
-4 The duty is limited only when shifting between the 2nd and 3rd gears, and when shifting between the 1st and 4th gears, in which the operation switching between the brake 23 and the 3-4 clutch 27 is performed together. The minimum value D _MIN (> 0%) and the maximum value D _MAX (<100%) are set in the ratio, and the duty ratio is determined in the above-described manner until the ratio reaches the minimum value or the maximum value. Then, after a predetermined time set in advance (0.4 seconds is set uniformly in the embodiment), the duty ratio is set to 0% or 100%.
To be. If the minimum value D _MIN or the maximum value D _MAX is reached before the set time, the minimum value D _MIN or the maximum value D _MAX is maintained until the set time elapses. FIGS. 10 and 11 schematically show such control modes. FIG. 10 shows the case of feedforward control in the direction in which the duty ratio decreases, and FIG. The figure shows the case of feedforward control in the direction in which the ratio increases.

The control of the second region as described above, the deviation of the actual turbine speed and the target turbine speed N _E is a predetermined value (Example 40
when the state became rpm) or less is maintained for a predetermined time, or when one is satisfied when the control time T _m of a second region has elapsed, it is terminated.

-3 Driving of DSL45B and 45C DSL45B and 45C are 2ms for both the 1st area and the 2nd area
The drive is performed at the duty ratio determined as described above by the interrupt processing for each ec. In addition, reading of the actual turbine speed is also performed by interruption every 2 msec. However, the actual turbine speed used for control is 6 pulses (12 mse
The average value during c) is used, and this average value is updated every pulse.

In the feedback control of the second area, DSL45B,
The timing for turning 45C ON and OFF is set as follows. That is, when the hydraulic pressure decreases (when S = -1), the actual turbine speed and the target turbine speed in each control cycle are compared, and the DSL45B or 45C is used until the values match. Is kept ON, and turned OFF after a match. When the hydraulic pressure increases (S = +
1) until the target turbine speed in each control cycle becomes equal to or higher than the actual turbine speed.
Alternatively, 45C is kept OFF, and remains ON after the target turbine speed becomes larger than the actual turbine speed. The reason for adopting such a method is to avoid situations where the DSL45B and 45C are frequently turned on and off every 16 ms in one control cycle. The responsiveness of the change will be taken into account.

FIGS. 12A and 13A show examples of the above two embodiments, FIG. 12A shows a case where the oil pressure decreases at the time of upshifting, and FIG. 13A shows an example of a case where the oil pressure increases at the time of downshifting Is shown. The manner in which the duty ratio changes over time is shown in FIG.
FIG. 2B is shown, and the one corresponding to FIG. 13A is shown as FIG. 13B. Note that, within a predetermined time (<T _m ) from the start of the control in the second area, the minimum value D _MIN and the maximum value D _MAX are set in the duty ratio, and until the control in the second area ends. , DSL45B, 45C do not become 0% or 100%.

Details of the control in the third area In the third area, first, the hydraulic pressure adjustment by the DSL 45B and 45C is completed.
ON or depending on the state of engagement and disengagement of clutch 27
OFF (duty ratio is 0% or 100%). Second
Then, as described later, a learning value for further optimizing the control values used in the above-described first and second regions is determined.

The determination of the learning value differs between for feedback control and for feedforward control. For feedback control, basically, DSL45B per control cycle during the feedback control in the second region, and 45C average ON time, it is determined on the basis of the final duty ratio D _L in the feedback control. Above 1 DSL45B in the control cycle, 45C average ON time of the average value by ON time of the second region all period (total ON time), divided by the set time T _m for controlling the second region D is determined as _mean . Then, according to the following equation (8), the primary learning value
D _S1 is determined.

From the primary learning value _DS1 obtained by the above equation (8), the final learning value _DS3 is determined by the following processing. That is, the primary learning value D obtained by the above equation (8)
_The secondary learning value D _S2 is determined by multiplying _S1 by the oil temperature correction coefficient and the throttle opening coefficient. Note that the oil temperature correction coefficient is determined so that the base value is at 80 ° C.
The throttle opening correction coefficient is determined so that the basic value is obtained when the throttle opening is 50%. Then, the secondary learning value for the shift mode (shift from first gear to second gear, etc.)
By arithmetic mean and the previous one and that of the current of the D _S2, the final learning value D _S3 is determined. If the previous learning value does not exist in the shift mode, the current 2
The next learning value _DS2 is used as it is as the initial value of the final learning value _DS3 .

On the other hand, the learning value D _S3 ′ in the case of feedforward control
Is determined as follows. First, the primary learning value _DS1 is
When the coefficient S indicating the oil pressure increase / decrease direction is “−1”, it is determined by the following equation (9), and when S is “+1”, it is determined by the following equation (10).

D _S1 ′ = D _MIN + ΔD × elapsed time (9) D _S1 ′ = D _MAX + ΔD × elapsed time (10) In the above equations (9) and (10), D _MIN and D _MAX are ,
This is as shown in FIG. 10 or FIG. In addition, the elapsed time is a time required to reach D _MIN or D _MAX as shown in FIGS. Of course, ΔD is given by equation (6).

Primary learning value expressed by the above equation (9) or (10)
D _S1 ′ is multiplied by an oil temperature correction coefficient and a throttle opening correction coefficient, like the secondary learning value D _S1 for feedback control, to obtain a secondary learning value D _S2 ′. Then, among the secondary learning values _DS2 ', the final learning value _DS3 ' is determined by arithmetically averaging the current value and the previous value. However, if the previous final learning value _DS3 'does not exist, the current secondary learning value _DS2 ' is used as (the initial value of) the final learning value _DS3 '.

The learning values _DS3 and _DS3 'for the feedback control and the feedforward control obtained as described above are stored (updated) in the RAM for each speed change mode.

FIGS. 14 and 15 show how the control is further optimized by the learning value determined as described above. FIGS. 14 and 15 show a case where a learning value does not exist for α rays and a case where a learning value exists for β rays.

Flowchart The flowchart for executing the control described above is described in FIG.
This is shown in FIGS. Hereinafter, this flowchart will be described. In the following description, P indicates a step.
Note that portions that are clear in the description so far will be described as simplified as possible.

FIG. 16 FIG. 16 shows the overall flow of control by the control unit U. That is, after the system initialization at P1 and the reading of the input signal at P2 are performed, the shift control, line pressure control, and lockup control are sequentially performed at P3 to P5.

Note that the line pressure control at P4 is for obtaining an optimal engagement force of a brake, a clutch, or the like according to the gear position, as is known.

FIG. 17 At P3 in FIG. 17, the shift is performed when a shift is performed,
The loop is turned every 16 msec. That is, the control of the first area, the control of the second area, and the control of the third area are sequentially performed, but the control of the next area is not performed unless the control of the previous area is completed.

FIG. 18 (control of first area) This corresponds to the process of P11 in FIG. First, the gear to be shifted is determined by P21, whereby the first gear to the third gear are determined.
A shift mode such as a shift to a high speed is determined. In P22, the throttle opening is read, and in P23, the control time t for the first region is read.
_T is determined. After this, by the processing of P24 to P27,
The duty ratio based on equation (1) is determined, and P2
At 8, the final duty ratio D is determined by the oil temperature correction (the output of D is made in a separate flow). Then, in P29, the control ends when the control time t _T has elapsed.

19A to 19C (control of second area) First, P31 to P40 and P51 to P55 are for feedback control. P58 to H63 and P83 are for feedforward control. P56, P57, and P64 to P66 are for the determination of the end of the second area and the subsequent processing.

Assuming the above, in P31-P35, DSL45
The DSL to be feedback-controlled is determined from B and 45C, and the flag for the DSL to be subjected to the feedback control is turned ON (P33 or P35). Also, P36
In P40, the target turbine speed N (k) of the next control cycle is finally determined (P40). Then, this determined N (k) is by treatment of P51～P55, is the final target turbine speed N _E after the shift to the range of the limit value.

In feedforward control starting from P59, P
The duty ratio D (k) is determined by the processing from 58 to P63. When the determinations of P71 and P72 are both NO, that is, when the set times shown in FIGS. 10 and 11 have not been reached, the processes of P73 to P76 are performed. This is the upper limit D
D (k) above as long as it does not exceed _MAX or the lower limit D _MIN
Is set. At the same time, the current elapsed time from the start of the control of the second area is updated by P76, P80, and P77. Further, the duty ratio setting after the lapse of the set time shown in FIGS. 10 and 11 is performed by the processes of P71, P72, and P81 to P83.

In the P56, and the deviation between the actual turbine rotational speed N and the target turbine speed N _E is below the set value, and when such a condition is determined to have continued for the predetermined time, the second region Is completed. In this case, P6
In 4, the elapsed time from the start of the control in the second area to the present time is stored as one mode of the learning value. You. Also, YES is determined in the determination of P57.
Is also the time to end the control in the second area, and in this case, the processes of P65 and P66 are performed. In addition,
Not perform processing P64 when the result is YES in the determination of P57, because the set time T _m of a this time was not always optimal.

FIGS. 20A and 20B (DSL drive control) FIGS. 20A and 20B show a case where feedback control is performed in the second area (feed control in the first area and the second area). For forward control, output is performed according to the duty ratio determined as described above).

Assuming the above, first, after confirming that the second region is being controlled in Q1, the target and the current turbine speeds N (k) and N are read in Q2 and Q3. Thereafter, by the processing of Q4 to Q18, FIG.
As described in the figure, DSL is basically turned on by the distinction between upshift and downshift, and + and-of S.
The control to turn off after turning on (Fig. 12A) or the control to turn on after turning off DSL (Fig. 12B) is identified. In the former case, the DSLON flag is set in Q18, and in the latter case, in Q7.
The DSLOFF flag is set. Q10, Q11, Q14, Q
The processing of 15 is for bringing the current turbine rotation speed N close to the target turbine rotation speed N (k), and depends on whether or not the set time in FIGS. 12A and 13A has elapsed in Q12 and Q16. D _MIN at Q13 or Q17 (Figure 13A), D
_A determination is made as to whether it is time to set _MAX (FIG. 12A).

After the above Q18, by the processing of Q25 to Q28 in FIG. 20B,
The feedback flag at P33 or P35 in FIG.
N-side DSL is turned on. Similarly, after Q7, the feedback flag is set by the processing of Q21 to Q24.
The DSL that is turned on is turned off.

After the processing of Q25 to Q28 or Q21 to Q24, in Q29, the value of k indicating the unit of 2 msec (indicating the ON or OFF time of 2 msec of DSL) is counted up.
Then, in Q30, it is determined whether or not this k is 7 (whether or not 14 msec has elapsed among 16 msec which is one control cycle). If the determination in Q30 is NO, the process is returned as it is. If the determination in Q30 is YES, the current ON time counter value is added to the total counter value of the time during which the DSL is ON after the control of the first area is started, by the processing in Q31 to Q33. Then, the total counter value is updated. At Q34, ON time count value of the current DSL is updated as D _L.

21A and 21B (control of third region) The flow of FIGS. 21A and 21B corresponds to the process of P15 in FIG. First, at R1, the DSL 45B, 45C is set to a duty ratio of 0% or 100% (OFF or ON) in response to the completion of the hydraulic pressure adjustment according to the shift speed after the shift. Thereafter, in R2, it is determined whether or not the learning flag is turned on. If the learning flag is turned on, the setting of the learning value performed as described later when the control of the second area is completed is performed. This means that (update) has already been performed (see FIG. 19P, FIG. P65, and FIG. 21B, FIG. R28). Therefore, when the determination of R2 is YES, the control for obtaining the learning value, which will be described later, has been completed, and the process ends.

If the determination of R2 is NO, by the process of shifting to R3,
The learning value is determined. That is, by the processing of R3 to R11, the final learning value D for feedback control described above is obtained.
_S3 is determined. Further, the processing of R21 to R26, the final learning value D _S3 for feedforward described above 'is determined.

R27~R29 the final learning value D _S3, 'a post-treatment after obtaining, the final learning value D _S3, D _S3 will be appreciated that' D _S3 is
It is stored in the RAM (R27). Further, the learning flag is turned on because the control for obtaining the learning value is ended (R28).
Finally, various data stored in the RAM for obtaining the current final learning value are cleared for new data input when obtaining the next learning value. The data to be cleared include the control time t _T of the first area, the control time T _m of the second area, the ON time count value of the DSL, and the OF time of the DSL.
F time count value, a total count value and a final duty ratio D _L of the DSL ON time.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an example of a torque converter and a multi-speed transmission gear mechanism. FIG. 2 is a diagram showing an example of a hydraulic circuit of the automatic transmission shown in FIG. FIG. 3 is a diagram showing a control system of the present invention. FIG. 4 is a diagram showing a first region, a second region, and a third region during shifting, together with a manner in which the turbine speed changes. Figure 5 is a diagram showing a map for determining the control time t _T of the first region. Figure 6 Figure showing a map for determining a correction factor C _4. FIG. 7 is a view showing a map for _obtaining a control time Tm of a second area. Figure 8 Figure showing a map for determining a correction coefficient C _1. FIG. 9 is a diagram showing the operation of the duty solenoid and the manner in which the turbine speed changes during feedback control performed in the second region. FIG. 10 and FIG. 11 are diagrams showing how the duty ratio changes during feedforward control in the second area. FIG. 12A is a diagram showing a state of duty control during feedback control in the second region. FIG. 12B is a diagram showing a state where the duty ratio changes over time by the duty control in FIG. 12A. FIG. 13A is a diagram showing a state of duty control during feedback control in the second region. FIG. 13B is a diagram showing a state where the duty ratio changes over time by the duty control in FIG. 13A. FIG. 14 is a diagram showing how control is optimized by a learning value for feedback control. FIG. 15 is a diagram showing how the control is optimized by a learning value for feedforward control. 16 to 21B are flowcharts showing a control example of the present invention. FIG. 22 is a block diagram showing the configuration of the present invention. 1: Torque converter 10: Multi-speed transmission gear mechanism 13: Turbine shaft 28a: Output shaft 23: Brake (friction fastening element) 27: Clutch (friction fastening element) 46, 47: Valve (for adjusting hydraulic pressure) 45B, 45C: Duty solenoid (For hydraulic adjustment) 213: Sensor (turbine speed) U: Control unit

Claims (3)

(57) [Claims] 1. A multi-stage transmission gear mechanism, comprising: a torque converter; and a multi-stage transmission gear mechanism that performs gear shifting by using a turbine rotation speed of the torque converter as an input rotation speed. In the automatic transmission configured to perform the above-described speed change, a first fastening force adjusting unit that adjusts a magnitude of a fastening force of a first friction fastening element among the friction fastening elements; Second fastening force adjusting means for adjusting the magnitude of the fastening force of the friction fastening element; rotation speed detecting means for detecting the turbine speed; and control for controlling the first fastening force adjusting means and the second fastening force adjusting means. Means for controlling the turbine speed at a predetermined speed when the engagement states of the first friction engagement element and the second friction engagement element change in directions opposite to each other, and While the change is occurring, the first frictional force adjusting means is feedback-controlled so that the turbine rotational speed detected by the rotational speed detecting means approaches a preset target rotational speed, while the second frictional engagement is performed. The second fastening force adjusting means is set to be feed-forward controlled so that the fastening force of the element changes at a predetermined rate of change, and the predetermined rate of change is set by the control means. Is corrected by the actual change rate of the turbine speed obtained based on the turbine speed detected by the speed detecting means and the target turbine speed change for each predetermined control cycle obtained based on the target speed. A shift control device for an automatic transmission, which is performed based on a deviation from a rate. 2. The system according to claim 1, wherein the predetermined shift is a shift-up time, and the predetermined change is set such that the actual change rate of the turbine speed is larger than the target turbine speed change rate by a predetermined value or more. A shift control device for an automatic transmission, wherein the shift ratio is corrected to be small. 3. The method according to claim 1, wherein the predetermined shift time is a shift-up time, and the predetermined change rate is set such that the actual change rate of the turbine speed is smaller than the target turbine speed change rate by a predetermined value or more. The shift control device for an automatic transmission, wherein the shift ratio is corrected to increase.