JPH0384260A - Line pressure control device for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce the generation of a speed change shock based on a torque phase period, an amount or a rate of a change in the number of revolutions of a turbine during the period, a line pressure in an inertia phase period is varied. CONSTITUTION:An ECU 100 controls a speed change of a multistage transmission mechanism 10 of an automatic transmission AT through an oil pressure control circuit 30 by means of parameters being a throttle opening and the number of revolutions of a turbine from sensors 101 and 102 based on a speed change pattern. During the speed change, a line pressure control means 103 drives a duty solenoid valve 33 so that a line pressure in an inertial phase period is controlled based on a torque phase period and/or an amount of a change in the number of revolutions of a turbine during the period or a rate of a change in the number of revolutions of a turbine during the torque phase period, and varies a line pressure regulated by a pressure regulator valve 32. Based on an increase and a decrease in the number of revolutions of a turbine, a line pressure is properly controlled, and the generation of a speed change shock can be reduced.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention' relates to a line pressure control device for an automatic transmission, particularly for an automatic transmission that controls line pressure by controlling a pressure regulating valve via a solenoid valve. This invention relates to a line pressure control device.

"Prior Art" Generally, an automatic transmission includes a torque converter and a transmission mechanism using a planetary gear mechanism, etc., and the transmission mechanism includes various clutches for switching power transmission paths,
A friction element for speed change such as a brake is provided. These friction elements are operated by a hydraulic control circuit, and by controlling a solenoid valve and the like incorporated in the hydraulic control circuit, the friction elements are engaged and opened, and a gear change is performed. The line pressure of this hydraulic control circuit is
It is related to the engagement force of the friction elements, the switching timing of the friction elements during gear changes, etc., and affects gear shift shock, etc., so it is required to be appropriately adjusted according to the driving conditions of the vehicle.

In order to electrically adjust the line pressure of such a hydraulic control circuit, the hydraulic control circuit is provided with a pressure regulating valve that regulates the line pressure, and the pilot pressure of the pressure regulating valve is controlled by a duty solenoid valve. Devices designed to control this are known. According to such a device, the line pressure is controlled by the duty ratio of the drive signal to the duty solenoid valve, thereby securing the necessary friction element engagement force against the torque from the engine, and also securing the necessary friction element engagement force during gear changes. Line pressure is adjusted to reduce shift shock.

``Problem to be Solved by the Invention'' In this type of conventional device, line pressure is controlled based on the shift time. For example, Tokuko Sho 63-3183
In the device shown in the publication, the actual shift time is compared with the desired shift time and line pressure is controlled based on the difference between rainfalls.

When controlling the line pressure based on the shift time in this way, it is not possible to perform line pressure control appropriate to the shift state. For example, if the turbine speed rises, this is due to slow engagement of the friction elements, and to prevent this, the line pressure must be increased, and the turbine speed pulls in. in case of,
This is because the friction elements are fastened, and to prevent this, it is necessary to reduce the line pressure. However, the conventional device does not take into account such an increase or decrease in the turbine rotational speed, and therefore cannot appropriately control the line pressure, resulting in a shift shock.

Furthermore, when controlling the line pressure based on the shift time, the line pressure is controlled at the end of the shift, and therefore the line pressure cannot be controlled quickly.

It is an object of the present invention to reduce shift shock by appropriately controlling line pressure based on the rise and fall of turbine rotation speed, and further to reduce line pressure by controlling line pressure at the beginning of gear shifting. An object of the present invention is to provide a line pressure control device for an automatic transmission that can quickly control the line pressure.

"Means for Solving the Problems" First, the first invention includes, in a hydraulic control circuit for a friction element of an automatic transmission, a pressure regulating valve for regulating line pressure of the hydraulic control circuit; A line pressure control device for an automatic transmission, comprising: a solenoid valve that controls a regulating valve; and a line pressure control means that controls the pressure regulating valve via the solenoid valve to control line pressure. The control means is characterized in that the control means is configured to change the line pressure during the inertia phase period based on the torque phase period and the amount of change in the turbine rotation speed during the torque phase period.

Further, in a second aspect of the invention, a hydraulic control circuit for a friction element of an automatic transmission includes a pressure regulating valve that adjusts line pressure of the hydraulic control circuit, and a solenoid valve that controls the pressure regulating valve. In a line pressure control device for an automatic transmission, the line pressure control device includes a line pressure control means for controlling a line pressure by controlling a pressure regulating valve via the solenoid valve. It is characterized by being configured to change the line pressure during the inertia phase period based on the amount of change in turbine rotation speed during the period.

Furthermore, in a third aspect of the invention, a hydraulic control circuit for a friction element of an automatic transmission includes: a pressure regulating valve that adjusts line pressure of the hydraulic control circuit; and a solenoid valve that controls the pressure regulating valve. In a line pressure control device for an automatic transmission, the line pressure control device includes line pressure means for controlling line pressure by controlling a pressure regulating valve via the electromagnetic valve, wherein the line pressure control means controls torque phase during gear shifting. It is characterized in that it is configured to change the line pressure during the inertia phase period based on the rate of change in the amount of change in turbine rotational speed with respect to the period.

"Operation" The shift period consists of a torque phase period and an inertia phase period following this, and in the present invention, the line pressure during the inertia phase period is changed according to the state of the turbine rotation speed during the torque phase period. I have to.

First, in the first invention, the line pressure during the inertia phase period is changed based on the torque phase period and the amount of change in the turbine rotation speed during the torque phase period.

Furthermore, in the second aspect of the invention, the line pressure during the inertia phase period is changed based on the amount of change in turbine rotational speed during the torque phase period.

Furthermore, in the third invention, the line pressure during the inertia phase period is changed based on the rate of change in the amount of change in turbine rotational speed with respect to the torque phase period.

"Example" Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the overall configuration of a line pressure control device for an automatic transmission according to an embodiment of the present invention.

1st! ! 1, the automatic transmission AT includes a torque converter 2 that receives an output from an engine E, a multi-stage transmission mechanism 10, and a hydraulic control circuit 30. The multi-stage transmission mechanism 1o incorporates various friction elements (brakes, clutches) that switch the power transmission path.
The engagement and release of each friction element is controlled by a hydraulic control circuit 30. Inside the hydraulic control circuit 30, there are a pressure regulator valve (pressure regulating valve) 32 that regulates the line pressure that becomes the hydraulic pressure supplied to the friction element, and a decourty solenoid valve 33 that controls the pressure regulator valve 32. The line pressure is regulated by the valves 32,33.

Reference numeral 100 denotes an electronic control unit (ECU) as a control section, which is composed of a microcomputer, etc., and this control unit 100 includes:
A signal from a throttle opening sensor 101 that detects the opening of a throttle valve provided in the intake passage of the engine E;
A signal from a turbine rotation speed sensor 102 that detects the turbine rotation speed of the torque converter 2 is inputted.

A drive signal 105 based on a duty signal is output from the control unit 100 to the duty solenoid valve 33.

The control unit 100 has a line pressure control means 103 that controls line pressure by setting a duty ratio of a drive signal 105 according to operating conditions and the like.

Note that the drive signal 105 output from the control unit 100 to the duty solenoid valve 33 is ○N.
The on-state and off-state are repeated, and the ratio of the on time in one cycle is the duty ratio, and this duty ratio can be changed by the line pressure control means 103 depending on the operating state.

In addition, the control unit 100 controls each of the solenoid valves 37, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 37, 40, 37, 37, 40, 40, 40, 40, 40, 40, 40, 40, 40, etc., the control unit 100 controls each solenoid valve 37, 40, . By controlling the lock-up solenoid valve 5, the lock-up solenoid valve 5, which will be described later, is controlled.
1 to lock-up clutch 2, which will be described later.
9 (see Figure 4).

FIG. 2 shows the structure of automatic transmission AT.

In FIG. 2, a torque converter 2 is connected to the output shaft l of the engine, and a multi-stage transmission mechanism IO is disposed on the output side of the torque converter 2. The torque converter 2 includes a pump 3 fixed to the output shaft 1 of the engine.
, a turbine 4 , and a stator 5 provided on a fixed shaft 7 via a one-way clutch 6 .

The multi-stage transmission mechanism 10 includes an oil pump driving solid shaft 12 whose base end is fixed to the output shaft load of the engine and whose tip end is connected to the oil pump 3I, and radially outward of the solid shaft 12, It includes a hollow turbine shaft 13 whose base end is connected to the turbine 4 of the torque converter 2, and on this turbine shaft 13, a Ravigneau-type planetary gear device 14 is provided. This planetary gear device 14 includes a small sun gear 15, a large diameter sun gear 16, a long pinion gear 17, a short pinion gear 18, and a ring gear 19. The following various friction elements are incorporated into this planetary gear device 14.

On the side far from the engine, a forward clutch 20 is connected between the turbine shaft 13 and the small sun gear 15.
and coast clutch 21 are arranged in parallel. The forward clutch 20 is a first one-way clutch 2
The coast clutch 21 connects and disconnects power transmission from the turbine shaft 13 to the small sun gear 15 via the turbine shaft 13 and the small sun gear 15 .

A brake drum 23a connected to the large-diameter sun gear 16 and a brake band 23 attached to the brake drum 23a are disposed radially outwardly of the coast clutch 21.
A 2-4 brake 23 with a
6 is fixed. A reverse clutch 24 for backward running is disposed on the side of the 2-4 brake 23 and connects and disconnects power transmission between the large-diameter sun gear 16 and the turbine shaft 13 via the brake drum 23a. A low reverse brake 25 that engages and disengages the carrier 14a and the case 10a is arranged between the carrier 14a of the planetary gear unit 14 and the case 10a of the transmission gear mechanism 10 on the outside of the planetary gear unit 14 in the radial direction. A second one-way clutch 26 is arranged in parallel with the brake 25.

A carrier 1 is provided on the side of the planetary gear device 14 on the engine side.
3- for intermittent power transmission between 4a and the turbine shaft 13;
4 clutches 27 are arranged.

An output gear 28 connected to a ring gear I9 is arranged on the side of this 3-4 clutch 27.
This gear 28 is attached to an out-up shaft 28a.

Furthermore, in the torque converter 2, reference numeral 29 denotes a lock-up clutch for directly connecting the output shaft 1 of the engine and the turbine shaft 13 without going through the torque converter 2.

The transmission gear mechanism 10 itself has four forward speeds and one reverse speed.
Clutch 20.21.24.27,
By operating the brakes 23, 25 as appropriate, a desired gear position can be obtained. Here, the relationship between each gear stage and the operation of each clutch and brake is shown in the following table.

FIG. 3 shows the hydraulic control circuit 30 in the automatic transmission AT. In FIG. 3, the hydraulic control circuit 30 has an oil pump 31 driven by the crankshaft 1,
Hydraulic oil is discharged from this pump 31 into the oil path L1.

The hydraulic oil discharged from the pump 31 into the oil path L1 is guided to the pressure regulator valve 32. The pressure regulator valve 32 regulates the hydraulic pressure (line pressure) of the hydraulic oil from the pump 31 and is controlled by a duty solenoid valve 33. That is, the hydraulic pressure of the hydraulic oil reduced to a predetermined pressure by the solenoid reducing valve 34 is duty-controlled by the duty solenoid valve 33. That is, the duty solenoid valve 33 is controlled by the drive signal 105 from the electronic control unit 100. The opening/closing time ratio is adjusted, and the amount of drain from the valve 33 is adjusted accordingly, thereby controlling the oil pressure to the valve 32. Then, by applying this oil pressure to the pressure regulator valve 32 as a pilot pressure, the line pressure is adjusted according to the pilot pressure.

The line pressure regulated by the pressure regulator valve 32 is supplied to port g of the manual shift valve 35. This manual shift valve 35 is manually shifted to P-R-N-D, 2, and Lunge, and hydraulic oil is supplied from port g to a predetermined port in each range.

When the manual shift valve 35 is set to lunge, it is communicated to boats a and e, and when it is set to 2 range, it is communicated to ports a and c,
When the D range is set, it is communicated with baud a and C, and when the R range is set, it is communicated with port f.

Port a of the manual shift valve 35 is connected to a 1-2 shift valve 36 via an oil line. A pilot pressure controlled by a 1-2 solenoid valve 37 acts on the 1-2 shift valve 36 . In the first gear, the 1-2 solenoid valve 37 is turned OFF, so that the spool of the 1-2 shift valve 36 is operated to the left in the figure, and the oil path leading to the apply chamber 23c of the 2-4 brake 23 is activated. The 1-2 solenoid valve 37 is turned on during the 2nd to 4th speeds, so that the 1-2 solenoid valve 37 is connected to the drain side.
The spool of the shift valve 36 is actuated to the right in the figure,
Hydraulic pressure from a) is supplied to the apply chamber 23c of the 2-4 brake 23 via an oil path. Furthermore, this 1-
The 2-shift valve 36 connects the low pressure reducing valve 38 from port e of the manual shift valve 35 when the lunge is in first gear.
Hydraulic oil is supplied to the low reverse clutch 25 via the hydraulic oil.

The oil pressure from port a of the manual shift valve 35 is
The pressure is also applied to the 2-3 shift valve 39 as pressure. This 2-3 shift oil valve 39 is connected to port C of the manual shift oil rib 35 via an oil line, and the pilot pressure is controlled by a 2-3 solenoid valve 40. And the first.
In 2nd gear, the 2-3 solenoid valve 40 is turned ON, so that the spool of the 2-3 shift valve 39 is operated to the right in the figure, and in this state, the 3-4 clutch 27
The oil passage leading to the drain side is communicated with the drain side, and the 3-4 clutch 27 is released. Also, at 3rd and 4th speeds, 2
By turning off the -3 solenoid valve 40, the spool of the 2-3 shift valve 39 is operated to the left in the figure, and in this state, the hydraulic pressure at port c of the valve 35 is sent to the oil path. , the 3-4 clutch 27 is engaged.

The oil passage Ls is also connected to a 3-4 shift valve 41, and a pilot pressure controlled by a 3-4 solenoid valve 42 acts on this 3-4 shift valve 41. When the 3-4 solenoid valve 42 is turned on, the spool of the 3-4 shift valve 41 moves to the right side in the diagram at the 1st, 2, and 4th speeds of the D range and the 1st speed of the 2nd range. and in this state,
2-4 Oil passage L leading to the release chamber 23d of the brake 23
6 is connected to the drain side. Also, at the 3rd speed of the D range, the 2.3rd speed of the 2nd range, and the 1.2nd speed of the lunge, the 3-4 solenoid valve 42 is turned OFF, so that the 3-4 shift valve 41 is turned off. The spool is operated to the left in the figure, and in this state, the oil passage L6 and the oil passage connected to the 2-3 shift valve 39 are communicated, and the 2-3 shift valve 39 is connected to the oil passage L6.
3. Depending on the operation of the shift valve 39, the release chamber 23d
Hydraulic pressure is supplied and discharged to and from. Furthermore, this 3-4 shift valve 41 performs this switching by switching the supply and discharge of hydraulic pressure between the oil path leading to port a of the manual shift valve 35 and the oil path leading to the coast clutch 21. The coast clutch 21 is released and engaged accordingly.

In this way, each shift valve 36.39.4 is controlled by a solenoid valve 37.40.42.
1, the 2-4 brake 23 (this 2-4 brake 23 is applied to the apply chamber 23c) is a friction element for shifting.
(It is engaged when hydraulic pressure is supplied and the hydraulic pressure in the release chamber 23d is drained, and is otherwise released) and 3-4
The clutch 27 is engaged and released as shown in the table above. In addition, each shift valve 36, 39, 41 and 2-
In the hydraulic circuit between the 4 brakes 23 and the 3-4 clutches 27, there are 1-2 accumulators 43, 2-3 accumulators 44, 2-3 timing valves 45, and 32 timing valves 46 for alleviating shift shocks. ,as well as,
A bypass valve 47 is incorporated.

In addition to the above, the hydraulic control circuit 30 includes D, 2,
The N-D accumulator 48 connected to the oil line that sends hydraulic pressure from bow a) and the core passage so that the forward clutch 20 is engaged in the lunge, and the reverse clutch 24 is engaged in the R range. An oil line that sends hydraulic pressure from port f to. and N-R connected to the oil passage L1°.
An accumulator 49, a lock-up control valve 50 for controlling the lock-up clutch 29, a lock-up solenoid valve 51 for controlling the valve 50, a converter relief valve 52, and the like are provided.

Next, FIG. 4 shows the relationship between turbine rotational speed and line pressure with respect to time in the control method using the line pressure control device according to the first embodiment of the present invention.

In FIG. 4, the gear shift is started at time t1, at which time the turbine rotational speed is T□7°, and the line pressure is changed from PLo to PLI. During the shift at time t2, the turbine rotational speed reaches a jerk value Tm5vp, and the time between time t and time t2 becomes a torque phase period T. At this time t, the torque phase period T and the torque phase period T.

Turbine rotation speed change amount ΔT miv (= T *s
vp-T RlV. ), the line pressure P during the inertia phase period T following the torque phase period T1.
.

is changed, and this change in line pressure PL will be explained below.

First, judging from the torque phase period T1 and the turbine rotational speed change amount ΔTl1tv, when the turbine rotational speed is shown by the ideal curve T□v1, there is no need to change the line pressure from PLl, and therefore, the inertia phase period T, Also, the line pressure is maintained at PLI. Furthermore, when the turbine rotational speed is shown by the blow-up curve T□v2, this is because the engagement of the friction elements is slow;
In order to prevent this blow-up, it is necessary to increase the line pressure from P, and therefore, during the inertia phase period T2
At , the line pressure is increased from P Ll to PL2. On the other hand, the turbine rotation speed is the pull-in curve TIEV
3, this is because the friction element is fast engaged, and in order to prevent this pull-in, the line pressure needs to be lowered from PLI. Therefore, during the inertia phase period T, the line pressure is P, to P
It is lowered to L3.

The line pressure correction amount PLa is obtained from the map shown in FIG. 5 based on the torque phase period T and the turbine rotational speed change amount ΔTiny.

In addition, as shown in FIG. 6, the torque phase period T
, the line pressure correction amount Pta increases, and as shown in FIG.
As IIV increases, the line pressure correction amount P also increases.

Next, FIG. 8 shows a flowchart of a control method by the line pressure control device according to the first embodiment of the present invention.

In FIG. 8, starting at step 200, at step 202, time 1. Shifting starts at step 2.
In step 04, the line pressure PL is changed from PLO to PLI, and in step 206, the actual turbine rotation speed Tl[lV is read, and in step 208, the target turbine rotation speed at the end of the shift is determined from the turbine rotation speed TlfVO at the start of the shift t1. T□
Vt1IO is determined by gear ratio, etc.

If T1itV≦T**vl:wo is not determined in step 210, the actual turbine rotational speed Tov is set to the target turbine rotational speed T.
□VEII. has not been reached, the process proceeds to step 212, and if the differential of Tlt, that is, d/dt T□, is not 0, the turbine rotational speed T-9 will increase or remain constant, so the process proceeds to step 21.4, and d /dtT**v
If not = 0, the turbine rotational speed T□V is increasing, so the process returns to step 206.

After that, if d/dtT□7=0 in the stave 214, the turbine rotational speed T□ is constant, so step 2
Step 16 determines the torque phase period T1, step 218 determines the turbine rotation speed T□vp (peak value) at time t, and step 220 determines the turbine rotation speed variation ΔTIIIv (=TII): vpT*tv. > is determined, and in step 222, the torque phase period T1 and the turbine rotational speed change amount ΔT□ are determined.

Based on the correction amount map (FIG. 5), the line pressure correction amount PLa is determined.

Then, in step 212, d/dt T ml! v
= 0, the actual turbine rotation speed T□V decreases, so proceed to step 224, change the line pressure PL from PLl (predetermined amount) to PL (predetermined amount) 10P (correction amount), As a result, the inertia phase period T.

Then, the line pressure Pt is changed to PLl+PL-.

In addition, in step 226, PLl (predetermined amount) is updated and P
Set LI (predetermined amount) + PL (correction amount).

After that, in step 210, Ti1v≦Tov□. , the actual turbine rotation speed T□9 becomes the target turbine rotation speed Ti
1l! Since VEII11 has been reached, step 22
Ends at 8.

Next, FIG. 9 shows the relationship between turbine rotation speed and line pressure with respect to time in a control method using a line pressure control device according to a second embodiment of the present invention.

In FIG. 9, the shift starts at time t1, and at this time the turbine rotational speed is 1. Ti! vo, and the line pressure is changed from PLo to PLI. During the shift at time t2, the turbine rotation speed reaches the peak value TR1VP,
The time between time t and time t2 is the torque phase period T,
become. At this time t2, the turbine rotational speed change amount ΔTRH9("T 1ivp
Based on T m[, vo), the torque phase period T1
The line pressure PL during the inertia phase period T2 that follows is changed, and this change in line pressure PL will be explained below.

First, the amount of change in the turbine rotational speed ΔT *, ! during the torque phase period T. Judging from v, when the turbine rotation speed is shown by the ideal curve TIIIVI, the line pressure is P,
Therefore, the line pressure is maintained at P Ll even during the inertia phase period T2. Furthermore, when the turbine speed is indicated by the blow-up curve T REV2, this is because the engagement of the friction elements is slow, and in order to prevent this blow-up, the line pressure is reduced to P.
Therefore, during the inertia phase period T2, the line pressure increases from PLI to PL2.
It is raised to On the other hand, when the turbine rotation speed is
When indicated by RFiv3, this is because the friction elements are fastened, and in order to prevent this pulling,
The line pressure needs to be reduced from PLI and therefore:
During the inertia phase period T, the line pressure is P
It is lowered from LI to PL3.

The line pressure correction amount PLa is obtained from the graph shown in FIG. 10 based on the turbine rotational speed variation ΔT RPV.

Next, FIG. 11 shows a flowchart of a control method by a line pressure control device according to a second embodiment of the present invention.

In FIG. 11, the start is at step 200, at step 202, gear shifting is started at time t1, and at step 204, the line pressure PL is changed from PLO to PLI,
In step 206, the actual turbine rotation speed T is determined. , read
In step 208, the turbine rotational speed T at the start of gear shift t1
From IEVO, target turbine rotation speed T 1t during gear shifting
Find vE*n using gear ratio, etc.

In step 210, TRHV≦T++iv): x. Otherwise, since the actual turbine rotation speed TREV has not reached the target turbine rotation speed T1lEVE+io, the process proceeds to step 212, and the differential of TR+:v, that is, d/dt
If T IIEV < 0, the turbine rotation speed T
Since REV is increasing or constant, the process proceeds to step 214, and if d /dt T 1ivO, the turbine rotational speed T, , is increasing, so the process returns to step 206.

Thereafter, in step 214 d /dt T w! v=
Since the turbine rotational speed Tl1tv is constant if it is O, the process proceeds to step 218, and in step 218, the turbine rotational speed T□7. Find (peak value),
In step 220, the amount of change in the turbine rotational speed ΔT may
(=T m1vp T 1ivo), and in step 222, the line pressure correction amount Pta is obtained from the correction amount graph (Fig. 1O) based on the turbine rotational speed change amount ΔT□7.

Then, in step 212, a/dt THEY < 0
Then, the actual turbine rotation speed T. Since y decreases, the process proceeds to step 224, where the line pressure PL is set to PL, (predetermined amount)
is changed to PLI (predetermined amount) + Pta (correction amount), and thereby, in the inertia phase period T2, the line pressure PL is changed to PLl + PLa.

In addition, in step 226, P, (predetermined amount) is updated to P,
(predetermined amount)+PLa (correction N).

Thereafter, in step 210, TiEv≦Tuitv.

[110, the actual turbine rotation speed T□7 is the target turbine rotation speed T l! Since V□ has been reached, the process ends at step 22.8.

Next, FIG. 12 shows the relationship between turbine rotational speed and line pressure with respect to time in a control method using a line pressure control device according to a third embodiment of the present invention.

In FIG. 12, the gear shift is started at time tl, at which time the turbine rotational speed is T□9°, and the line pressure is changed from PLll to P. During the shift at time t2, the turbine rotational speed reaches a peak value Tm1vp, and the time between time t1 and time t becomes a torque phase period T. At this time t, the turbine rotational speed change amount ΔT iiv (= T l!V
P T 1ivo), i.e. ΔT, v/T1
Based on this, the line pressure PL during the inertia phase period T following the torque phase period T is changed, and this change in line pressure PL will be described below.

First, judging from the rate of change of the turbine rotational speed variation ΔTi1v with respect to the torque phase period T, that is, ΔT-9/T, when the turbine rotational speed is shown by the ideal curve T□□, the line pressure is changed from PLI. There is no need,
Therefore, even during the inertia phase period T, the line pressure is maintained at PLI. Moreover, when the turbine rotation speed is shown by the blow-up curve Tm1v2, this is
This is because the engagement of the friction element is slow, and in order to prevent this blow-up, it is necessary to increase the line pressure from PLI.
Therefore, during the inertia phase period T2, the line pressure is increased from PLl to TL2. On the other hand, when the turbine speed is shown by the pull-in curve TIIIVI, this is because the friction elements are fast engaged, and in order to prevent this pull-in, the line pressure needs to be lowered from PLI, and therefore the inertia During phase period T, the line pressure is reduced from PLI to PL3.

The above line pressure correction amount PLa can be determined from the graph shown in FIG.
obtained based on.

Next, FIG. 14 shows a flowchart of a control method by a line pressure control device according to a third embodiment of the present invention.

In FIG. 14, the shift starts at step 200, and at step 202, the shift is started at time t, and at step 204, the line pressure Pt is changed from PLO to PLI,
In step 206, the actual turbine rotation speed T□9 is read,
In step 208, the turbine rotational speed T of 1+ at the start of the shift
From i1liVO, the target turbine rotation speed T at the end of the shift
Find □□ using gear ratio, etc.

In step 210, T IEV≦Tll: vll, lfl
Otherwise, since the actual turbine rotation speed T■7 has not reached the target turbine rotation speed TIEVEIII+, the process proceeds to step 212, and the differential of TliV, that is, /dtT
If iiv < 0, the turbine rotation speed T
tT□.

If it is not 20, the turbine rotation speed T□9 has increased, so the process returns to step 206.

Then, in step 214, d/dt T msv =
If it is 0, the turbine rotation speed T7 is constant, so the process proceeds to step 216 to find the torque phase period T1, and in step 218 the turbine rotation speed Tm1vp (peak value) at time t2 is found, and in step 220 The amount of change in turbine speed ΔT□v (=T□□−T□9°) is determined in step 222, and the rate of change of the amount of change in turbine speed ΔT□7 with respect to the torque phase period T1, that is, ΔT
Based on iiv/T+, the line pressure correction amount PLa is determined from the correction amount graph (FIG. 13).

Thereafter, in step 212 d/dt T iiv
< 0, the actual turbine rotational speed T liV
Since the line pressure P decreases, the process proceeds to step 224 and the line pressure P
.

PL, (predetermined amount) to PLl (predetermined amount) + p L
a (correction amount), and thereby, in the inertia phase period T2, the line pressure P is changed to PLllPL-. Note that in step 226, PLl (predetermined amount)
is updated to PLI (predetermined amount) + PL, (correction amount).

Then, in one step 210, T l! V≦Ti1via
Then, the actual turbine rotation speed T ++iv is the target turbine rotation speed Tl! v! Since Nfl has been reached, the process ends at step 228.

``Effects of the Invention'' As explained above, according to the present invention, during a gear shift, the transmission is performed based on the torque phase period and the amount of change in the turbine rotation speed during the torque phase period, or based on the amount of change in the turbine rotation speed during the torque phase period. The line pressure during the inertia phase period is configured to be changed based on the change rate of the turbine rotational speed change amount with respect to the torque phase period.

Therefore, it is possible to reduce shift shock by appropriately controlling the line pressure based on the rise and pull of the turbine speed, and furthermore, by controlling the line pressure at the beginning of the shift, the line pressure can be controlled quickly. I can do it.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a line pressure control device for an automatic transmission according to an embodiment of the present invention, Fig. 2 is a structural diagram of the automatic transmission, and Fig. 3 is a circuit diagram of a hydraulic control circuit in the automatic transmission. 4 is a graph showing a control method using the line pressure control device according to the first embodiment of the present invention, and FIG. 6 is a graph showing the relationship between the torque phase period and the line pressure correction amount. FIG. 7 is a graph showing the relationship between the turbine rotational speed change and the line pressure correction amount. 9 is a flowchart of a control method using a line pressure control device according to a first embodiment of the present invention, FIG. 9 is a graph diagram showing a control method using a line pressure control device according to a second embodiment of the present invention, and FIG. 11 is a flowchart of the control method by the line pressure control device according to the second embodiment of the present invention, and FIG. A graph diagram showing a control method by a line pressure control device according to a third embodiment of the invention, FIG. FIG. 14 is a flowchart of a control method by a line pressure control device according to a third embodiment of the present invention. 2... Torque converter, 10... Multi-stage transmission mechanism, 30... Hydraulic control circuit, 32... Pressure regulator valve, 33...
Duty solenoid valve, 100... control unit, 103... line pressure control means. Fig. 4 (Start of shift M) (During gear shift) (End of shift) Fig. 5 T1 (Torque phase period) Fig. 6 Fig. 7 (8"-') (9-Mourning i""') Fig. 9 Figure 10 (9-Main “2)

Claims (3)

[Claims] (1) A hydraulic control circuit for a friction element of an automatic transmission is provided with a pressure regulating valve that adjusts the line pressure of the hydraulic control circuit, and a solenoid valve that controls the pressure regulating valve. A line pressure control device for an automatic transmission including a line pressure control means for controlling line pressure by controlling a pressure regulating valve via a solenoid valve, wherein the line pressure control means controls a torque phase period and the torque during a shift. A line pressure control device for an automatic transmission, characterized in that the line pressure during an inertia phase period is changed based on the amount of change in turbine rotational speed during the phase period. (2) A hydraulic control circuit for friction elements of the automatic transmission is provided with a pressure regulating valve that adjusts the line pressure of the hydraulic control circuit, and a solenoid valve that controls the pressure regulating valve. A line pressure control device for an automatic transmission including a line pressure control means for controlling line pressure by controlling a pressure regulating valve via a solenoid valve, wherein the line pressure control means controls turbine rotation during a torque phase period during gear shifting. 1. A line pressure control device for an automatic transmission, wherein the line pressure control device for an automatic transmission is configured to change the line pressure during an inertia phase period based on the amount of change in number. (3) A hydraulic control circuit for friction elements of the automatic transmission is provided with a pressure regulating valve that adjusts the line pressure of the hydraulic control circuit, and a solenoid valve that controls the pressure regulating valve. A line pressure control device for an automatic transmission including a line pressure control means for controlling line pressure by controlling a pressure regulating valve via a solenoid valve, wherein the line pressure control means controls turbine rotation for a torque phase period during gear shifting. A line pressure control device for an automatic transmission, characterized in that the line pressure control device for an automatic transmission is configured to change a line pressure during an inertia phase period based on a rate of change in a number change amount.