JPH1047469A - Up-shifting control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce shift shock by temporarily increasing an escape pressure of a first fastening element when a sensed gear ratio reaches a preset value indicating the timing immediately before completion of an inertial phase at the determination of up-shifting. SOLUTION: Hydraulic application is eliminated from a first fastening element (a) based on determination of a traveling time up-shifting determination means (c), while hydraulic pressure is applied to a second fastening element (b). The fastening elements (a) and (b) are brought into sliding conditions. An inertial phase where a transmission gear ratio is varied is started. When a gear ratio reaches a preset value indicating the timing immediately before the phase is completed, an up-shifting escape pressure control means (f) outputs a command to an escape pressure controlling actuator (e) for temporarily increasing an escape pressure of the fastening element (a). The escape pressure of the fastening element (a) which is substantially under a released condition is increased again, bringing about substantially an interlocked state. A part of an output shaft torque is cut immediately before completion of the inertial phase. Torque difference before and after completion of the inertial phase is suppressed. Shock is thus reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upshift control device for an automatic transmission, and more particularly to a technique for controlling an accumulator back pressure of an engagement element on a release side during an upshift transition period.

[0002]

2. Description of the Related Art Conventionally, upshifts in automatic transmissions are
When the upshift is started and the input pressure to the engaged clutch reaches a certain pressure, the accumulator back pressure of the disengaged clutch is drained by the timing control based on the switching operation of the sequence valve and the like to reduce the clutch release pressure. Reduce the hydraulic capacity and end shifting.

In this upshift, when the throttle opening is low during gear shifting, the change in engine rotation (turbine rotation) is small, and the above-described timing control can suppress the shock sufficiently. When the opening is medium to high, as shown in FIG. 9, the rotation change of the engine rotation (turbine rotation) accompanying the shift is large, the rotation change due to the inertia (inertia) rides on the output shaft, and the output shaft A shock that greatly reduces the torque occurs.

Japanese Patent Laid-Open Publication No. 2-229959 discloses a technique for reducing the shock in the shift end region of the upshift, when an upshift is started and the speed ratio reaches a speed ratio indicating a time immediately before the end of the inertia phase. There is disclosed a technique for temporarily reducing the input pressure to a clutch to be engaged, delaying the progress of a shift, and reducing a change in rotation of engine rotation (turbine rotation).

[0005]

However, in the above-mentioned conventional upshift control apparatus, since the shift progress speed is slowed down by the input pressure reduction control at the time of the upshift, the input pressure is sufficiently reduced to suppress the shock. If the reduction allowance is increased, the shift time is lengthened and the shift is prolonged. On the contrary, if the input pressure reduction allowance is reduced, the shift time is shortened, but there is a problem that the shock remains. In other words, when only the input pressure reduction control is used, the control is performed by setting the input pressure reduction allowance so as not to lengthen the shift time, and there is a limit in suppressing the dust shock.

The problems to be solved by the present invention are listed below.

The first problem is that the hydraulic pressure is released from the first fastening element that was fastened at the gear position before the upshift and the hydraulic pressure is applied to the released second fastening element to change the gear position after the upshift. In an upshift control device for an automatic transmission to be achieved, it is an object of the present invention to provide a shift transient hydraulic control for reducing a shift shock without increasing a shift time during an upshift.

The second object is to achieve the first object by a simple and high-response accumulator back pressure control.

A third object of the present invention is to provide a shift transient hydraulic control which achieves both a high-level shift shock mitigation and an appropriate shift time at the time of an upshift.

The object 4 is to achieve the object 3 by controlling the accumulator back pressure with high response.

[0011]

[Means for Solving the Problems]

(Solution 1) Solution 1 of the above problem 1 (Claim 1)
As shown in the claim correspondence diagram of FIG. 1, the hydraulic pressure is released from the first fastening element a that was fastened at the gear position before the upshift and the hydraulic pressure was applied to the second fastening element b that was released. In an upshift control device for an automatic transmission for achieving a gear position after an upshift, an upshift determining means c for determining whether an upshift is performed, a gear ratio detecting means d for detecting a gear ratio, an upshift determination When the detected gear ratio reaches the set gear ratio indicating the timing immediately before the end of the inertia phase, an instruction to temporarily increase the release pressure of the first fastening element a is output to the release pressure control actuator e. Shift release pressure control means f;
It is characterized by having.

The operation will be described.

During traveling, when the upshift determination means c determines that an upshift is being performed, the hydraulic pressure is released from the first engagement element a by switching the shift valve and the like, and the hydraulic pressure is applied to the second engagement element b. Is supplied. And
When the first engagement element a and the second engagement element b both slip and the inertia phase in which the gear ratio changes is started, and when the detected gear ratio reaches the set gear ratio indicating the time immediately before the end of the inertia phase, the upshift is performed. Evacuation pressure control means f
, A command to temporarily increase the release pressure of the first fastening element a is output to the release pressure control actuator e.

Therefore, the release pressure of the first fastening element a, which is almost released at the time immediately before the end of the inertia phase of the upshift, rises again and the first fastening element a increases the fastening capacity, so that the first fastening element a tends to be interlocked. This first
Due to the fastening capacity of the fastening element a, a part of the output shaft torque is cut off immediately before the end of the inertia phase. Therefore, the torque difference between the peak output shaft torque immediately before the end of the inertia phase and the output shaft torque after the end of the inertia phase is suppressed to a small value, and the shock caused by the magnitude of the torque difference is reduced.

On the other hand, the shift transient hydraulic control of the upshift is a control for increasing the release pressure of the released first fastening element a to cut a part of the output shaft torque. The shift time does not become longer as in the case of delaying the shift by reducing the input pressure of the fastening element b.

(Solution 2) Solution 2 of the above problem 2
(Claim 2) is, as shown in the claim correspondence diagram of FIG.
2. The upshift control device for an automatic transmission according to claim 1, wherein a first accumulator (g) is provided in the middle of an oil passage of the first fastening element (a), and an accumulator pressure to the back pressure chamber of the first accumulator (g). A timing valve h for switching over the supply of the accumulator pressure from the back pressure chamber, a timing solenoid as the release pressure control actuator e, and the upshift release pressure control means f
When the upshift is determined and the detected gear ratio reaches the set gear ratio indicating the timing immediately before the end of the inertia phase, the side is temporarily switched to the side that supplies the accumulator pressure to the back pressure chamber of the first accumulator g. A means for outputting a command to the timing solenoid is provided.

The operation will be described. During an upshift, when the detected gear ratio reaches a set gear ratio indicating the time immediately before the end of the inertia phase, the upshift release pressure control means f
In, a command to temporarily switch to the side for supplying accumulator pressure to the back pressure chamber of the first accumulator g is output to the timing solenoid.

Therefore, the timing valve h is switched from the drain side to the supply side by a command to the timing solenoid, and the accumulator pressure is supplied to the back pressure chamber of the first accumulator g, thereby releasing the first fastening element a. The pressure rises temporarily in response to the accumulator back pressure rise.

(Solution 3) Solution 3 of Problem 3
(Claim 3) is, as shown in the claim correspondence diagram of FIG.
3. The upshift control device for an automatic transmission according to claim 1, wherein when the upshift is determined and the detected gear ratio reaches a first set gear ratio indicating an inertia phase start timing, the second shift control is performed. The second pressure indicating the time immediately before the end of the inertia phase is increased by increasing the input pressure to the fastening element b.
Upshift input pressure control means j for outputting a command to temporarily lower the input pressure to the second fastening element b when the set gear ratio is reached to the input pressure control actuator i is provided.

The operation will be described. In the upshift input pressure control means j, when the upshift is determined, the detected gear ratio indicates the first inertia phase start timing.
When the set gear ratio is reached, the input pressure to the second fastening element b is increased, and when the set gear ratio reaches the second set gear ratio indicating the time immediately before the end of the inertia phase, the input pressure to the second fastening element b is temporarily reduced. A command to perform the control is output to the input pressure control actuator i.

Therefore, during a predetermined period after the gear ratio reaches the second set gear ratio, the release pressure of the first fastening element a is increased and the input pressure to the second fastening element b is reduced at the same time. Owing to the synergistic effect of the partial reduction of the output shaft torque and the suppression of the change speed of the engine rotation (turbine rotation) due to the decrease of the input pressure, the shock in the shock is greatly reduced.

In addition, during the period from the first set gear ratio indicating the start timing of the inertia phase to the second set gear ratio indicating the time immediately before the end of the inertia phase, the input pressure increase control to the second fastening element b is performed. Then, the speed at which the gear ratio changes is increased, so that the second fastening element b
Even if the shift speed is slightly reduced due to a decrease in the input pressure, the total shift time does not increase.

(Solution 4) Solution 4 of Problem 4
(Claim 4) is, as shown in the claim correspondence diagram of FIG.
The upshift control device for an automatic transmission according to claim 3, wherein a second accumulator (k) is provided in the middle of an oil passage of the second fastening element (b), and a back pressure of the second accumulator (k) is controlled. A pressure control valve m; a hydraulic control solenoid as the input pressure control actuator i; and an upshift input pressure control means j.
When the set gear ratio is reached, the back pressure of the second accumulator k is increased, and the second pressure indicating the time immediately before the end of the inertia phase is increased.
When the set gear ratio is reached, the second accumulator k is temporarily
Means for outputting a command to lower the back pressure to the hydraulic control solenoid.

At the time of the upshift, when the detected gear ratio reaches the first set gear ratio indicating the inertia phase start timing, the upshift input pressure control means j raises the back pressure of the second accumulator k to increase the inertia. When the second set gear ratio indicating the time immediately before the end of the phase is reached, a command to temporarily lower the back pressure of the second accumulator k is output to the hydraulic control solenoid.

Therefore, the accumulator back pressure control valve m
Then, a hydraulic pressure according to a command to the hydraulic control solenoid is generated, and this control hydraulic pressure is supplied as an accumulator pressure to the back pressure chamber of the second accumulator k, so that the input pressure of the second fastening element b is reduced. It changes in response to changes in pressure.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Embodiment 1 is an upshift control device for an automatic transmission corresponding to Solution 1 to Solution 3.

First, an overall outline of an automatic transmission to which the upshift control device according to the first embodiment is applied will be described.

FIG. 2 is a skeleton diagram showing a power transmission mechanism of the automatic transmission.

In FIG. 2, IN is an input shaft, OUT is an output shaft, FPG is a front planetary gear, RPG is a rear planetary gear, and the front planetary gear FPG is a first sun gear S.
1, a first ring gear R1, a first pinion P1, and a first pinion carrier C1.
Sun gear S2, second ring gear R2, and second pinion P2
And a second pinion carrier C2.

Using the gear train, 4 forward speeds, 1 reverse speed
A reverse clutch R is used as a fastening element for obtaining a high speed.
EV / C (hereinafter R / C), high clutch HIGH / C
(Hereinafter, H / C), a 2-4 brake 2-4 / B, a low clutch LOW / C (hereinafter, L / C), a low & reverse brake L & R / B, and a low one-way clutch LOW OWC.

The first sun gear S1 is connected to the input shaft IN via a first rotating member M1 and a reverse clutch R / C, and the first rotating members M1 and 2-4.
It is connected to the case K via the brake 2-4 / B.

The first carrier C1 is connected to the input shaft IN via a second rotating member M2 and a high clutch H / C, and via a third rotating member M3 and a low & reverse brake L & R / B. It is connected to the case K. The first carrier C1 is provided with a third rotating member M3.
And the second ring gear R2 via a low clutch L / C. In addition, low & reverse brake L & R /
A low one-way clutch LOW OWC is provided in parallel with B.

The first ring gear R1 is directly connected to the second carrier C2 via a fourth rotating member M4.
The output shaft OUT is directly connected to the second carrier C2.

The second sun gear S2 is directly connected to the input shaft IN.

The characteristics of this power transmission mechanism are as follows: 4-3
A one-way clutch that was adopted to obtain a shift timing without shift shock during upshifting,
The use of this one-way clutch eliminates the use of a hydraulically-engaged clutch required to secure engine braking, and achieves a reduction in size and weight by reducing the number of fastening elements.

FIG. 3 shows the above-described power transmission mechanism for the fourth forward speed.
FIG. 7 is a diagram illustrating engagement logic for obtaining a first reverse speed.

The first speed (1st) is a low clutch L / C
And the hydraulic engagement of the low & reverse brake L & R / B (when the engine brake range is selected) or the mechanical engagement of the low one-way clutch LOW OWC (when accelerating). That is, the second sun gear is input, the second ring gear is fixed, and the second carrier is output.

The second speed (2nd) is a low clutch L / C
And 2-4 brake hydraulic pressure 2-4 / B. That is, the input is the second sun gear input, the first sun gear fixed, and the second carrier output.

The third speed (3rd) is a high clutch H / C
And the low clutch L / C is hydraulically engaged. That is, the simultaneous input of the second ring gear and the second sun gear,
Carrier output (speed ratio = 1).

The fourth speed (4th) is a high clutch H / C
And 2-4 brake hydraulic pressure 2-4 / B. That is, the overdrive speed is set by the first carrier and the second sun gear input, the first sun gear fixed, and the second carrier output.

The reverse speed (Rev) is determined by the reverse clutch R
It is obtained by hydraulically engaging the EV / C and the low & reverse brake L & R / B. That is, the first and second sun gears are input, the first carrier is fixed, and the second carrier is output.

The 2-4 brake 2-4 / B is a multiple disc brake having the same structure as the multiple disc clutch.

FIG. 4 shows the first to fourth ranges of the D range among the above-mentioned shift speeds.
FIG. 3 is a control system diagram showing a fastening element, a control valve unit, and an electronic control unit for achieving automatic speed change.

FIG. 4 shows a low clutch L as a fastening element.
/ C, 2-4 brake 2-4 / B, and high clutch H / C
Is provided.

The control valve section of FIG. 4 includes a shift valve (A) 1, a shift valve (B) 2, an accumulation control valve (A) 3, an accumulation control valve (B) 4, and a low clutch timing valve. 5
, A low clutch sequence valve 6, a 2-4 brake timing valve 7, a 2-4 brake sequence valve 8, a low clutch accumulator 9, a 2-4 brake accumulator 10, and a high clutch accumulator 11. .

The shift valve (A) 1 and the shift valve (B) 2 are operated in the first to fourth speeds (O to O) according to the operation of the shift solenoid (A) 21 and the shift solenoid (B) 22.
The oil path is switched at each shift speed of D).

The accumulation control valve (A) 3
Is the line pressure PL according to the magnitude of the solenoid pressure PSOLA generated by the line pressure duty solenoid 23.
And accumulate control pressure (A) to adjust PACCMA. The solenoid pressure PSOLA generated by the line pressure duty solenoid 23 is also guided to a pressure modifier valve for adjusting a modifier pressure which is a signal pressure of the line pressure PL generated by a pressure regulator valve (not shown).

The accumulation control valve (B) 4
Reduces the line pressure PL in accordance with the magnitude of the solenoid pressure PSOLB generated by the 2-4 / B duty solenoid 24, and regulates the accumulation control pressure (B) PACCMB.

The low clutch timing valve 5 is
When the low clutch timing solenoid 25 is turned off, the signal pressure oil passage is set to the drain side, and when the low clutch timing solenoid 25 is turned on, the signal pressure oil passage is set to the communication side by generating hydraulic pressure.

The low clutch sequence valve 6 is
The back pressure control of the low clutch accumulator 9 is performed at the time of upshifting to the fourth speed or at the time of downshifting from the fourth speed.

The 2-4 brake timing valve 7
Means that the 2-4 brake timing solenoid 26 is OFF
The switching valve sets the signal pressure oil passage to the drain side at the time of, and sets the signal pressure oil passage to the communication side by generating oil pressure at the time of ON.

The 2-4 brake sequence valve 8
Performs the back pressure control of the 2-4 brake accumulator 10 when shifting up to the third speed or downshifting from the third speed.

In the low clutch accumulator 9, the accumulating control pressure (A) PACCMA is guided to the back pressure chamber via the low clutch sequence valve 6, and the low clutch L / C is smoothly engaged and released.

The 2-4 brake accumulator 10
The accumulator control pressure (B) PACCMB is guided to the back pressure chamber via the 2-4 brake sequence valve 8 to smoothly apply and release the 2-4 brake 2-4 / B.

The high clutch accumulator 11
Accumulation control pressure (A) PACCMA is guided to the back pressure chamber as it is to smoothly engage and disengage the high clutch H / C.

The electronic control unit shown in FIG. 4 includes a shift solenoid (A) 21 as an actuator for controlling a hydraulic pressure in accordance with a drive command from the A / T control unit 20.
, Shift solenoid (B) 22, line pressure duty solenoid 23, 2-4 / B duty solenoid 24
And low clutch timing solenoid 25 and 2-4 / B
A timing solenoid 26 is provided.

As information sources for providing input information to the A / T control unit 20, a throttle sensor 27 for detecting a throttle opening, a vehicle speed sensor 28 for detecting a vehicle speed, and a turbine sensor 2 for detecting turbine rotation are provided.
9, an oil temperature sensor 30 for detecting the oil temperature, and other sensors
Switches 31 are provided.

The shift control for automatically shifting the first to fourth speeds in the D range is performed based on a shift point characteristic model diagram as shown in FIG. 6 and the detected throttle opening and vehicle speed.
A shift command is issued when the vehicle crosses the upshift or upshift shift line, and the next shift gear position is determined according to the shift command, and in order to obtain the determined gear position, the shift solenoid operation table shown in FIG. 5 is obtained. A / T
Shift solenoid from control unit 20 (A)
ON or O for 21 and shift solenoid (B) 22
It is controlled by issuing an FF command.

Next, the operation will be described.

[2-3 Electronic Control Operation of Upshift] FIG. 7 shows a 2-4 brake 2-4 / B (corresponding to the first fastening element a).
5 is a flowchart showing a flow of an upshift control operation performed by the A / T control unit 20 at the time of a 2-3 upshift in which is released and a high clutch H / C (corresponding to a second engagement element b) is engaged.

First, in step 70 of FIG.
It is determined whether or not a 3 upshift has occurred. This decision
The determination is made based on the output of the 2-3 upshift command signal across the 2-3 upshift line on the shift point model characteristics shown in FIG. (Corresponding to upshift determination means c).

If it is determined that the time is 2-3 upshift, a timer value T representing an elapsed time from the determination is used.
Is performed, and necessary input information such as the throttle opening TH is read.

When it is determined that a 2-3 upshift has occurred, the vehicle speed (transmission output shaft speed) from the vehicle speed sensor 28 and the tie bin rotation (transmission input shaft speed) from the turbine sensor 29 are used to determine the actual speed. The gear ratio G is calculated as needed (corresponding to the gear ratio detecting means d).

Further, if it is determined that it is the time of the 2-3 upshift, a command to the shift solenoid (A) 21 is set to O.
With the FF left, a shift control for switching a command to the shift solenoid (B) 22 from ON to OFF is performed.

If it is determined that it is during the 2-3 upshift, (1) release pressure control (steps 71 to 78)
And (2) input pressure control (steps 79 to 86) and (3) torque down control (steps 87 to 94), respectively.

(1) Release pressure control (corresponding to upshift release pressure control means f) In step 72, the 2-4 / B timing solenoid 26
An ON command is output to (equivalent to the release pressure control actuator e), and a command with a high duty ratio is output to the 2-4 / B duty solenoid 24.

In step 73, it is determined whether the timer value T is equal to or greater than the first set timer value T1. Note that the first set timer value T1 is set to a time required from the start of gear shifting to the end of the piston stroke of the high clutch H / C.

In step 74, the ON command to the 2-4 / B timing solenoid 26 is maintained as it is,
A command is issued to the duty solenoid 24 to reduce the duty ratio from a high duty ratio at once, and to gradually reduce the duty ratio with the passage of time.

In step 75, it is determined whether the actual gear ratio G is equal to or less than the second set gear ratio G2. Incidentally, the second set gear ratio G2 is set to a value close to the gear ratio at the third gear position after the shift indicating the timing immediately before the end of the inertia phase.

In step 76, the command for the 2-4 / B timing solenoid 26 is switched from the ON command to the OFF command, and the duty ratio of the 2-4 / B duty solenoid 24 is increased by reducing the reduced duty ratio. Is output.

In step 77, it is determined whether or not the timer value T is equal to or more than the shift end timer value T2.

In step 78, YES in step 77
Is determined, the command to the 2-4 / B timing solenoid 26 is switched from the OFF command to the ON command.
A command is output to the 4 / B duty solenoid 24 to return to the high duty ratio at the start of shifting.

(2) Input pressure control (corresponding to upshift input pressure control means j) In step 80, the line pressure duty solenoid 23
A command with a low duty ratio is output to the input pressure control actuator i.

In step 81, it is determined whether the actual gear ratio G is equal to or less than the first set gear ratio G1. The first set gear ratio G1 is set to a value close to the gear ratio at the second gear position before the shift, which indicates the inertia phase start timing.

In step 82, a command is issued to the line pressure duty solenoid 23 with the duty ratio rising at a predetermined gradient and the duty ratio after the startup is maintained as it is.

In step 83, it is determined whether the actual gear ratio G is equal to or less than the second set gear ratio G2.

In step 84, a command is output to the line pressure duty solenoid 23 to reduce the duty ratio at a predetermined gradient and to maintain the reduced duty ratio as it is.

At step 85, it is determined whether or not the timer value T is equal to or more than the shift end timer value T2.

In step 86, YES in step 85
Is determined, a command is output to the line pressure duty solenoid 23 to return to a duty ratio for performing normal line pressure control corresponding to the throttle opening.

(3) Torque-Down Control In step 88, the engine torque is maintained as it is.

In step 89, it is determined whether the timer value T is equal to or greater than the first set timer value T1.

At step 90, a command to gradually reduce the engine torque is output. In the case of torque-down control using a throttle valve, control is performed by decreasing the throttle opening, and in the case of torque-down control by fuel cut, control is performed by gradually increasing the number of fuel cut cylinders. It is.

In step 91, it is determined whether the actual gear ratio G is equal to or less than the first set gear ratio G1.

In step 92, a command to suppress the engine torque is output. In the case of the torque-down control using the throttle valve, the control is performed by the throttle fully-closed control. In the case of the torque-down control by the fuel cut, the control is performed by the fuel cut control of all the cylinders or the set cylinder.

In step 93, it is determined whether the actual gear ratio G is equal to or less than the third set gear ratio G3. Note that the third set gear ratio G3 (<G2) is set to a value very close to the gear ratio at the third gear position after the shift, which indicates immediately before the end of the inertia phase.

In step 94, YES in step 93
Is determined, a command to return the engine torque to the original is output.

The low clutch timing solenoid 2
5, an ON command is output.

[2-3 Upshift Control Operation] The 2-3 upshift control operation at medium to high throttle opening will be described with reference to a time chart shown in FIG.

When the shift is determined to be 2-3 upshift due to the increase of the vehicle speed while traveling with the accelerator depressed, the command to the shift solenoid (B) 22 is switched from ON to OFF, and the high clutch H / C is switched from the drain side to the D range pressure supply side,
The oil path to the -4 brake 2-4 / B is switched from the D range pressure supply side to the drain side.

Then, the 2-4 brake 2-4 /
The release pressure control from B is performed by the 2-4 brake accumulator 10 provided in the middle of the oil path to the 2-4 brake 2-4 / B.
The pressure control to the high clutch H / C during the shift period is performed by the high clutch accumulator provided in the middle of the oil passage to the high clutch H / C. 11 (corresponding to the second accumulator k), and the torque down control during the shift transition period is performed by the A / T control unit 20.
By outputting a control command to the engine control unit.

(1) Release pressure control operation In the region from the start of the upshift to the time when the second set gear ratio G2 is reached, the following is required.
Since the ON command is output to the 4 / B timing solenoid 26, the 2-4 / B timing valve 7 (corresponding to the timing valve h) is set to the high signal which is the operation signal pressure of the 2-4 brake sequence valve 8. It has been switched to the side that communicates the clutch pressure PH / C.

Accordingly, when the differential pressure ΔP between the accumulation control pressure (A) PACCMA and the high clutch pressure PH / C reaches the set differential pressure, the 2-4 brake sequence valve 8 sets
The mode switches from the side supplying the accumulator control pressure (B) PACCMB to the four-brake accumulator 10 to the side draining.

Therefore, the 2-4 brake pressure P2-4 / B is
As shown by the P2-4 / B characteristic in FIG. 8, the characteristic shows a sudden decrease from the shelf pressure characteristic at the switching point of the 2-4 brake sequence valve 8.

The shift progresses as the 2-4 brake pressure P2-4 / B decreases, and the actual gear ratio G becomes equal to the second set gear ratio G.
2-4 / B in the area from 2 to the end of gear shifting
The output to the timing solenoid 26 is switched from the ON command to the OFF command, and the command to the 2-4 / B duty solenoid 24 is also switched to a command to increase the duty ratio.

Therefore, in the 2-4 brake sequence valve 8, the high clutch pressure PH / C acting on one end of the valve spool is drained, and only the accumulation control pressure (A) PACCMA is used as the operation signal pressure again. The brake accumulator 10 switches to the side that supplies the accumulator control pressure (B) PACCMB.

Therefore, the 2-4 brake pressure P2-4 / B is
As shown in the P2-4 / B characteristic of FIG. 8, the characteristic shows that the oil pressure rises again from the time of the OFF command to the 2-4 / B timing solenoid 26 to the end of the shift.

(2) Injection pressure control operation In the region from the start of the upshift to the time when the inertia phase starts to reach the first set gear ratio G1, a command with a low duty ratio is output to the line pressure duty solenoid 23. Therefore, the low-pressure accumulator control pressure (A) PACCMA increases the high clutch accumulator 1
1 back pressure chamber.

For this reason, the high clutch pressure PH / C is calculated as shown in FIG.
As shown in the PH / C characteristics of the above, after the passage of the clutch piston stroke range, the oil pressure gradually rises to the accumulator back pressure level.

In the inertia phase region from the first set gear ratio G1 to the second set gear ratio G2, a high duty ratio command is output to the line pressure duty solenoid 23 to increase the high pressure. Accumulation control pressure (A) PACCMA is supplied to the back pressure chamber of the high clutch accumulator 11.

For this reason, the high clutch pressure PH / C is calculated as shown in FIG.
As shown in the PH / C characteristics of FIG.

Further, when the actual gear ratio G is equal to the second set gear ratio G2
In the region from when the gearshift has been reached to the end of the shift, a command with a low duty ratio is output to the line pressure duty solenoid 23 again, so that the low-pressure accumulator control pressure (A) PACCMA becomes high clutch accumulator 1.
1 back pressure chamber.

For this reason, the high clutch pressure PH / C is calculated as shown in FIG.
As shown in the PH / C characteristics, the oil pressure decreases in the shift end region.

(3) Torque-Down Control Function In particular, in the inertia phase region from the first set gear ratio G1 to the third set gear ratio G3 immediately before the end of the inertia phase, the engine is designed to reduce the output shaft torque TQ. Control for reducing the torque is performed.

[Shock Reduction Action] As described above,
In the release pressure control from the 4-brake 2-4 / B, in the region from when the actual gear ratio G reaches the second set gear ratio G2 indicating the time immediately before the end of the inertia phase to the end of the gear shift,
4. The brake pressure P2-4 / B temporarily increases in response to the increase in the accumulator back pressure.

Therefore, the 2-4 brake 2-4 / B, which is almost released at the time immediately before the end of the inertia phase of the upshift, becomes slightly interlocked by increasing the engagement capacity. A part of the output shaft torque TQ is cut off just before the end of the inertia phase due to the engagement capacity of. That is, the portion indicated by hatching in the output shaft torque characteristic in FIG. 8 is the effect margin in the release pressure control.

Also, as described above, the high clutch H / C
In the input pressure control, when the actual gear ratio G reaches the second set gear ratio G2 indicating the time immediately before the end of the inertia phase and ends in the shift, that is, in the same region as the release pressure control, the high clutch pressure PH / C is temporarily reduced by a low duty ratio command to the line pressure duty solenoid 23.

Therefore, the speed of change of the engine rotation (turbine rotation), that is, the speed of change of the gear ratio, is reduced by reducing the engagement capacity of the high clutch H / C which is almost in the engaged state immediately before the end of the inertia phase of the upshift. Is suppressed. That is, the peak output shaft torque immediately before the end of the inertia phase is suppressed to a low level.

As described above, in the range from when the second set gear ratio G2 is reached to the end of the shift, the increase in the release pressure of the 2-4 brake 2-4 / B and the decrease in the input pressure to the high clutch H / C are reduced. At the same time, the peak output shaft torque and the inertia phase just before the end of the inertia phase are obtained by the synergistic effect of partially reducing the output shaft torque TQ due to the increase in the extraction pressure and suppressing the change speed of the engine rotation (turbine rotation) due to the decrease in the injection pressure. The damping shock determined by the torque difference from the output shaft torque after the termination is greatly reduced.

In addition, since the torque-down control for reducing the engine torque in the inertia phase region is also used, the output shaft torque TQ is suppressed to a low value in the inertia phase region, and a good shift quality without shock is achieved. Incidentally, the dotted line characteristic in the output shaft torque characteristic of FIG. 8 indicates the characteristic when the torque down control is not performed.

[Time Required for Shifting] In the case of adopting a control for reducing the input pressure of the fastening element to be engaged in the shift transient hydraulic control of the upshift and delaying the progress of the shift, a reliable shock prevention effect is intended. The larger the input pressure reduction amount, the longer the shift time.

On the other hand, according to the present invention, since the release pressure of the 2-4 brake 2-4 / B released by the upshift is increased to reduce a part of the output shaft torque TQ, the shift time becomes longer. Never.

Further, in the present application, the control for reducing the input pressure of the high clutch H / C engaged in the upshift is also used, but from the first set gear ratio G1 indicating the start time of the inertia phase to the time immediately before the end of the inertia phase. The second showing
Up to the set gear ratio G2, the input pressure increase control to the high clutch H / C is performed, so that the shift progress speed at which the gear ratio changes in this region is increased. Even if the shift progress speed is slightly reduced due to the decrease in the input pressure, the total shift time does not increase.

Next, effects will be described.

(1) At the time of the 2-3 upshift determination, when the actual gear ratio G reaches the second set gear ratio G2 indicating the time immediately before the end of the inertia phase, the 2-4 brake 2-4 / B until the shift is completed. 2-4 / B OFF command to increase the release pressure
Since the apparatus is provided with an upshift release pressure control means for outputting to the timing solenoid 26, a shift transient hydraulic control for mitigating a shift shock (don't shock) without increasing the shift time during 2-3 upshifts is provided. Can be.

(2) A 2-4 brake accumulator 10 is provided in the oil passage of the 2-4 brake 2-4 / B.
2-4 brake sequence valves 8 and 2-4 / 2 for switching between supply of accumulator pressure to the back pressure chamber of brake accumulator 10 and removal of accumulator pressure from the back pressure chamber.
A B timing valve 7 is provided, a 2-4 / B timing solenoid 26 is provided as a release pressure control actuator, and the upshift release pressure control means is switched to a second set gear ratio G2 that indicates the time immediately before the end of the inertia phase. When the shift is reached, the OF is switched to the side supplying the accumulator pressure to the back pressure chamber of the 2-4 brake accumulator 10 until the shift is completed.
Since the F command is output to the 2-4 / B timing solenoid 26, a simple and high-response accumulator back pressure control can reduce shift shock without lengthening the shift time during 2-3 upshifts. Hydraulic control can be provided.

(3) At the time of upshift determination, when the detected actual gear ratio G reaches the first set gear ratio G1 indicating the inertia phase start timing, the input pressure to the high clutch H / C is increased. When the gear ratio reaches the second set gear ratio G2 indicating the time immediately before the end of the inertia phase, 2-4 until the shift is completed.
Since the upshift input pressure control means for outputting a duty command for reducing the input pressure to the brake 2-4 / B to the line pressure duty solenoid 23 is provided, a high-level shift shock mitigation and a shift time during 2-3 upshifts are provided. It is possible to provide a shift transient hydraulic control that achieves compatibility with optimization.

(4) A high clutch accumulator 11 is provided in the middle of the oil passage of the high clutch H / C, and an accumulation control valve (A) 3 for controlling the back pressure of the high clutch accumulator 11 is provided. The line pressure duty solenoid 23 is provided, and the upshift input pressure control means is controlled by the first set gear ratio G1 indicating that the detected actual gear ratio G indicates the inertia phase start timing.
, The back pressure of the high clutch accumulator 11 is increased, and when a second set gear ratio G2 indicating a time immediately before the end of the inertia phase is reached, a duty command for reducing the back pressure of the high clutch accumulator 11 until the shift is completed is transmitted to the line pressure duty solenoid. 23, the accumulator back pressure control with high response
It is possible to provide a shift transient hydraulic control that achieves both a high-level shift shock mitigation and an appropriate shift time during an upshift.

(Other Embodiments) In the first embodiment, the example of the 2-3 upshift has been described. However, the low clutch L / C is released and the 2-4 brake 2-4 / B is engaged. It can be applied to the case of 3-4 upshift.
In this case, the back pressure of the low clutch accumulator 9 is controlled by the low clutch sequence valve 6. The upshift control of the present invention can be applied to a 4-5 upshift when the automatic transmission has 5 speeds.

In the first embodiment, an example in which the release pressure and the input pressure are controlled by the back pressure control of the accumulator has been described. However, the release pressure and the input pressure may be controlled by directly controlling the clutch hydraulic pressure and the brake hydraulic pressure. .

In the first embodiment, an example of a system in which two line pressure duty solenoids 23 and a 2-4 / B duty solenoid 24 are used as the duty solenoids, but at least one duty solenoid is used as the duty solenoid for controlling the accumulator pressure. The present invention can also be applied to a system provided with a solenoid.

In the first embodiment, when the 2-3 upshift is determined, the release pressure control of the first engagement element and the input pressure control of the second engagement element are performed irrespective of the magnitude of the throttle opening. However, the release pressure and the input pressure may be controlled only when the throttle opening is medium to high, which causes a problem of the shock. Incidentally, even when the throttle opening is low as in the first embodiment, there is no particular problem even if the release pressure and the injection pressure are controlled.

In the first embodiment, an example was given in which a predetermined increase in the release pressure and a decrease in the input pressure were given at the time of 2-3 upshift. However, depending on the magnitude of the throttle opening, the larger the throttle opening, the larger the throttle opening. An embodiment may be used in which the amount of increase in the withdrawal pressure and the amount of decrease in the injecting pressure are large.

[0123]

According to the first aspect of the present invention, the hydraulic pressure is released from the first fastening element that has been fastened at the gear position before the upshift and the hydraulic pressure is released to the second fastening element that has been released. In the upshift control device for an automatic transmission that achieves the gear position after the upshift by inserting the gear ratio, the upshift determination unit determines the upshift, and the gear ratio detected by the gear ratio detection unit is the timing immediately before the end of the inertia phase. When the gear ratio reaches the set gear ratio, the device includes an upshift release pressure control means for temporarily outputting a command to increase the release pressure of the first fastening element to the release pressure control actuator. It is possible to provide shift transient hydraulic control for reducing shift shock without lengthening.

According to the second aspect of the present invention, the first aspect
In the upshift control device for an automatic transmission according to the present invention, a first accumulator is provided in the middle of the oil passage of the first fastening element, and the accumulator pressure is supplied to a back pressure chamber of the first accumulator from the back pressure chamber. A timing valve for switching the accumulator pressure rejection is provided, a timing solenoid is provided as a release pressure control actuator, and the upshift release pressure control means is used for upshift determination, and the detected gear ratio is just before the end of the inertia phase. When a set gear ratio is reached, a command to temporarily switch to the side for supplying accumulator pressure to the back pressure chamber of the first accumulator is output to the timing solenoid, so that the accumulator back pressure control with simple and high response allows The effect of the invention described in claim 1 can be achieved.

According to the third aspect of the present invention, the first aspect
In the upshift control device for an automatic transmission according to claim 2, when the upshift is determined and the detected gear ratio reaches a first set gear ratio indicating an inertia phase start timing, the operation is shifted to a second engagement element. Increase the filling pressure of
Upshift input pressure control means for temporarily outputting to the input pressure control actuator a command to reduce the input pressure to the second fastening element when the second set gear ratio indicating the time immediately before the end of the inertia phase is reached is provided. It is possible to provide shift transient hydraulic control that achieves both a high-level shift shock mitigation and a proper shift time at the time of a shift.

According to the invention set forth in claim 4, claim 3
In the upshift control device for an automatic transmission according to the present invention, a second accumulator is provided in the middle of an oil passage of the second fastening element, and an accumulator back pressure control valve for controlling a back pressure of the second accumulator is provided. A hydraulic control solenoid is provided as a pressure control actuator, and the upshift input pressure control means is used to increase the back pressure of the second accumulator when the detected gear ratio reaches a first set gear ratio indicating the inertia phase start timing. A means for temporarily outputting to the hydraulic control solenoid a command to reduce the back pressure of the second accumulator when the gear ratio reaches the second set gear ratio indicating the time immediately before the end of the phase. Item 3 can achieve the effects of the invention.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing an upshift control device for an automatic transmission according to the present invention.

FIG. 2 is a skeleton diagram showing a power transmission mechanism of the automatic transmission to which the hydraulic control device according to the first embodiment is applied.

FIG. 3 is a diagram illustrating a fastening logic table of the automatic transmission to which the hydraulic control device according to the first embodiment is applied.

FIG. 4 is an overall system diagram showing a hydraulic control unit and an electronic control unit to which the upshift control device according to the first embodiment is applied.

FIG. 5 is a diagram showing a shift solenoid operation table of the hydraulic control device according to the first embodiment.

FIG. 6 is a diagram illustrating an example of a shift point characteristic model of the hydraulic control device according to the first embodiment.

FIG. 7 is a flowchart illustrating a flow of a 2-3 upshift control operation performed by the A / T control unit according to the first embodiment;

FIG. 8 is a time chart showing each transient characteristic such as a control command, a hydraulic pressure, a gear ratio, and an output shaft torque during a 2-3 upshift in the first embodiment.

FIG. 9 is a time chart showing transient characteristics of output shaft torque, turbine speed, input pressure, and release pressure at the time of 2-3 upshift in the conventional device.

[Explanation of symbols]

a first fastening element b second fastening element c upshift determining means d gear ratio detecting means e release pressure control actuator (timing solenoid) f upshift release pressure control means g first accumulator h timing valve i input pressure control Actuator (hydraulic control solenoid) j Upshift input pressure control means k Second accumulator m Accumulator back pressure control valve

Claims (4)

[Claims] 1. A gear position after an upshift is achieved by releasing hydraulic pressure from a first fastening element that was fastened at a gear position before an upshift and applying hydraulic pressure to a released second fastening element. An upshift control device for an automatic transmission, comprising: an upshift determining means for determining whether an upshift is being performed; a gear ratio detecting means for detecting a gear ratio; Upshift release pressure control means for temporarily outputting to the release pressure control actuator a command to increase the release pressure of the first fastening element when a set gear ratio indicating a time immediately before the end of the phase is reached. Upshift control device for automatic transmission. 2. The upshift control device for an automatic transmission according to claim 1, wherein a first accumulator is provided in the middle of an oil passage of the first fastening element, and a first accumulator is provided to a back pressure chamber of the first accumulator. Providing a timing valve for switching between accumulator pressure supply and accumulator pressure exclusion from the back pressure chamber, providing a timing solenoid as the release pressure control actuator, the upshift release pressure control means, when determining an upshift, Means for outputting, to the timing solenoid, a command for temporarily switching to a side for supplying accumulator pressure to the back pressure chamber of the first accumulator when the detected gear ratio reaches a set gear ratio indicating a time immediately before the end of the inertia phase. An upshift control device for an automatic transmission, characterized by: 3. The upshift control device for an automatic transmission according to claim 1, wherein the gear ratio detected at the time of upshift determination is a first set gear ratio indicating an inertia phase start timing. When it reaches, the input pressure to the second fastening element is increased, and when it reaches the second set gear ratio indicating the time immediately before the end of the inertia phase, the command to temporarily reduce the input pressure to the second fastening element is input pressure control. An upshift control device for an automatic transmission, comprising upshift input pressure control means for outputting to an actuator. 4. The upshift control device for an automatic transmission according to claim 3, wherein a second accumulator is provided in the middle of an oil passage of the second fastening element, and a back pressure of the second accumulator is controlled. An accumulator back pressure control valve is provided, a hydraulic control solenoid is provided as the input pressure control actuator, and the upshift input pressure control means is turned on when the detected gear ratio reaches a first set gear ratio indicating an inertia phase start timing. Means for increasing the back pressure of the accumulator 2 and temporarily outputting a command to lower the back pressure of the second accumulator to the hydraulic control solenoid when the second set gear ratio indicating the time immediately before the end of the inertia phase is reached. An upshift control device for an automatic transmission, characterized by: