JP2969631B2 - Electronically controlled automatic transmission - Google Patents

Description

Description: Object of the Invention (Industrial Application Field) The present invention relates to an electronically controlled automatic transmission mounted on a vehicle, and more particularly to a clutch or brake for an engagement side of an automatic transmission. The present invention relates to an electronically controlled automatic transmission that gradually performs a combination.

2. Description of the Related Art Conventionally, in an automatic transmission for a vehicle, there is known a technique in which a clutch or a brake of an automatic transmission is gradually engaged, not suddenly engaged. This is intended to prevent abrupt clutch and brake engagement by gradually changing the engagement ratio and reduce shock.

(Problems to be Solved by the Invention) However, in the conventional device, since the engagement ratio is gradually increased from the start of engagement, the power transmission ratio is reduced at a low load even if the angle of the increase is increased. I will.

In view of the above, an object of the present invention is to prevent a reduction in power transmission efficiency at the time of starting engagement of a clutch or a brake on an engagement side at a low load.

[Configuration of the invention]

(Means for Solving the Problems) The technical means used in the present invention for solving the above problems includes a clutch and a brake which are operated by application of a fluid pressure, and the engagement and disengagement of the clutch and the brake. An automatic transmission for changing the gear ratio according to the combination, a fluid pressure switching means for controlling the application of fluid pressure to the clutch and the brake, and the fluid pressure switching means for driving the clutch and the brake in accordance with a running state of a vehicle. An electronic control means for changing engagement / disengagement of the electronically controlled automatic transmission, wherein a load detection means for detecting a load on the vehicle, and an engine speed detection means for detecting an engine speed. Setting means for setting the ratio setting at the start of engagement of the mating clutch or brake at a high load at a low load and a low setting at a high load. During shifting, after instructing the fluid pressure switching means to release the clutch or brake on the release side, the engagement of the clutch or brake on the engagement side is engaged by the engagement start ratio set by the setting means. And then instructs the fluid pressure switching means to gradually increase the engagement ratio.

(Operation) According to the above technical means, when the load on the vehicle is high, the engagement ratio at the time of starting the engagement can be kept low. At a low load, the ratio of engagement at the start of engagement increases. For this reason, when the load is low, the engagement is quickened, and the responsiveness is improved. At a high load, since the engagement is performed slowly, the shock is reduced. Further, since the overlap time of the hydraulic control of the clutch or the brake on the engagement side and the release side can be made uniform, the precision of the shift can be improved.

(Example) Hereinafter, an example using the present invention will be described with reference to the drawings. In the present embodiment, the automatic transmission main body uses a conventionally used 4-speed (with overdrive).

The operation of the automatic transmission will be described with reference to FIG. The turbine shaft 600, which is the input shaft of the overdrive mechanism 607, is connected to the engine via a torque converter. This turbine shaft 600 is the carrier 6 of the planetary gear set.
Connected to 09. Planetary pinion 610 rotatably supported by carrier 609 is OD planetary gear 601
Through the input shaft 611 of the gear transmission mechanism 608. The planetary pinion 610 is in mesh with the sun gear 612. A one-way clutch 606 and an OD clutch C0 are provided between the sun gear 612 and the carrier 609. An OD brake B0 is provided between the sun gear 612 and the housing 613. The input shaft 611 and the intermediate shaft 614 of the gear transmission 608
Between them, a forward clutch C1 is provided. A direct clutch C2 is provided between the input shaft 611 and the sun gear shaft 615. Sun gear shaft 615 and housing 6
13 and a second brake B1 is provided. A planetary pinion 619 rotatably supported by a carrier 617 coupled to the output shaft 605 includes a gear and a carrier 618.
Through an intermediate shaft 614. The planetary pinion 619 is in mesh with the sun gear shaft 615. Planetary pinion 612 meshes with carrier 617 and sun gear shaft 615. Planetary pinion 621 and housing 6
13 and a 1st and Rev brake B2 is provided. A one-way clutch 616 is provided between the planetary pinion 621 and the housing 613.

In this automatic transmission, the relationship between the clutches CO, C1, C2 and the brakes B0, B1, B2 and the shift speeds is as shown in the table below.

The clutches CO, C1, C2 and the brakes B0, B1, B2 are
The engagement and release are controlled by the hydraulic circuit shown in the figure.

Referring to FIG. 2, the hydraulic oil pumped by a hydraulic pump 702 from an oil reservoir 701 is controlled by a line pressure control solenoid valve 48, and a pressure adjusting valve 703 adjusts the oil pressure of a line pressure oil passage 704. The line pressure oil passage 704b is connected to the line pressure oil passage 704 via the pressure regulating valve 703, but the solenoid valve 41 for controlling the clutch C0 and the clutch C2
The solenoid valves are connected to manual valves 705, 706, 707, 708, and 709 via a control solenoid valve 42, a brake B0 control solenoid valve 43, a brake B1 control solenoid valve 44, and a brake B2 control solenoid valve 45, respectively.
The output of the hydraulic pump 702 is directly connected to the manual valves 705, 706, 707, 708, 709. The outputs of the manual valves 705, 706, 707, 708 are connected to the clutch C0, the clutch C2, the brake B0, and the brake B1, respectively. The output of the manual valve 709 is connected to the brake B2 via the valve 710. The valve 710 is connected to the shift valve 711 through the low / reverse prohibition solenoid valve 46.
It is connected to the. Shift valve 711 is also connected to manual valve 706. The shift valve 711 moves in response to the operation of the shift lever, and receives a hydraulic pressure from the hydraulic pump 702 inside the shift valve at times other than the P range. At the time of 1st, 2nd, 3rd and OD, clutch C
Hydraulic pressure is applied to 1. Then, the hydraulic pressure is supplied to the manual valve 706 in the L and R ranges, and the hydraulic pressure is supplied to the low and reverse prohibition solenoid valves 46 in the L and R ranges.

With this configuration, the solenoid valve for clutch C0 control
When the valve 41 is opened, the valve of the manual valve 705 moves, the output of the hydraulic pump 702 is applied to the clutch C0, and the clutch C0 is engaged. When the clutch C0 control solenoid valve 41 is closed, no oil pressure is applied to the clutch C0, and the clutch C0 is released.

The hydraulic pressure is applied to the clutch C1 at the time of 1st, 2nd, 3rd, and OD, and is engaged.

In the clutch C2, if the solenoid valve 42 for controlling the clutch C2 is opened, the valve of the manual valve 706 moves,
Oil pressure is applied to the clutch C2, and the clutch C0 is engaged.
When the clutch C2 control solenoid valve 42 is closed, no oil pressure is applied to the clutch C2, and the clutch C2 is released. However, when the shift valve 711 is in the L, 2 range, the hydraulic pressure is supplied to the manual valve 706, and the hydraulic pressure to the clutch C2 is cut regardless of the movement of the solenoid valve 42 for controlling the clutch C2.

In the brake B0, if the brake B0 control solenoid valve 43 is opened, the valve of the manual valve 707 moves,
The hydraulic pressure is no longer applied to the brake B0, and the brake B0 is released. When the brake B0 control solenoid valve 43 is closed, hydraulic pressure is applied to the brake B0, and the brake B0 is engaged.

In the brake B1, if the brake B1 control solenoid valve 44 is opened, the valve of the manual valve 708 moves,
The hydraulic pressure is no longer applied to the brake B1, and the brake B1 is released. When the brake B1 control solenoid valve 44 is closed, hydraulic pressure is applied to the brake B1, and the brake B1 is engaged.

In the brake B2, if the solenoid valve 45 for brake B2 control is opened, the valve of the manual valve 709 moves,
The hydraulic pressure is no longer applied to the brake B2, and the brake B2 is released. If the brake B2 control solenoid valve 45 is closed, hydraulic pressure is applied to the brake B2 via the valve 710,
The brake B2 is engaged. However, at the time of the R range and the L range, the solenoid valve 46 for low and reverse prohibition is set.
When is turned on, the hydraulic pressure is applied to the valve 710 to cut off the supply of the hydraulic pressure to the brake B2, and the brake B2 is released.

In another configuration, reference numeral 712 denotes a lock-up control valve, and when the lock-up control solenoid valve 47 is turned on, the output shaft of the engine and the turbine rotating shaft 600 are directly connected to each other to be in a lock-up state.

Each solenoid valve is driven by an electronic control circuit to be described later, and each clutch / brake is set to a first position in accordance with running conditions.
It is controlled so as to have a table relationship. Each solenoid valve is operated at a relatively high frequency by an electronic control circuit described later.
The opening degree of each manual valve can be adjusted by repeating ON-OFF and controlling the duty ratio. When the duty ratio is increased, the manual valve is greatly opened, and the hydraulic pressure generated by the hydraulic pump 702 is quickly applied to each clutch / brake, so that the operating speed of each clutch / brake is increased. Also, when the duty ratio is reduced, the opening of the manual valve decreases, and it takes time for the hydraulic pressure generated by the hydraulic pump 702 to reach each clutch / brake, and the operating speed of each clutch / brake decreases. Therefore, by controlling the duty ratio, the operating speed of each clutch / brake can be adjusted, and the shock generated when each clutch / brake is engaged can be reduced, and the transmission efficiency can be improved.

FIG. 3 shows an electronic control circuit for driving each solenoid valve in the hydraulic circuit.

An input terminal of a constant voltage power supply 22 is connected via an ignition switch 21 to a terminal of a battery 20 mounted on the vehicle. Central processing unit CP is connected to the output of constant voltage power supply 22.
U power supply terminals VCC and GND are connected. The constant voltage power supply 22 converts the output voltage of the battery 20 into a voltage at which the central processing unit CPU can operate.

Each input terminal of the central processing unit CPU has an engine rotation sensor 23, a turbine rotation sensor 24, and an output shaft rotation sensor 2
5, throttle sensor 26, neutral start switch 2
7. The overdrive cut switch 31, the idle switch 32 and the brake switch 33 are connected. Third
In the figure, the input interface of each sensor and switch is omitted for simplicity.

The engine rotation sensor 23 is a sensor that detects the rotation speed of the engine of the vehicle. The engine rotation sensor is provided near the output shaft of the engine, and outputs a pulse signal having a frequency corresponding to the rotation speed of the engine. In this embodiment,
The engine rotation sensor is a rotation sensor of an electromagnetic pickup type installed opposite to the teeth of a ring gear attached to the output shaft of the engine.
Output pulse. This output is sent to the central processing unit CPU.

The turbine rotation sensor 24 is a sensor that detects the number of rotations of the turbine. The turbine rotation sensor is disposed near the turbine rotation shaft, and outputs a pulse signal having a frequency according to the rotation speed of the turbine. In the present embodiment, the turbine rotation sensor is a rotation sensor of an electromagnetic pickup type installed facing the teeth of the gear mounted on the turbine shaft 600, and outputs 57 pulses for one rotation of the gear. This output is sent to the central processing unit CPU.

The output shaft rotation sensor 25 is a sensor that detects the rotation speed of the output shaft of the automatic transmission. The output shaft rotation sensor is provided near the output shaft of the automatic transmission, and outputs a pulse signal having a frequency corresponding to the rotation speed of the output shaft of the automatic transmission. In the present embodiment, the output shaft rotation sensor is a rotation sensor of an electromagnetic pickup type installed facing the teeth of the gear attached to the output shaft, and outputs 18 pulses for one rotation of the gear. This output is sent to the central processing unit CPU. The output shaft rotation sensor may be replaced by another type of vehicle speed sensor that detects the speed of the vehicle, provided that the relationship between the output shaft of the automatic transmission and the rotation speed of the wheels is clearly understood.

The throttle sensor 26 is a sensor that detects the opening of the throttle valve of the engine. The throttle sensor detects the rotation angle of the throttle valve with a switch and divides the opening of the throttle valve into digital and mechanical throttle sensors. The throttle sensor converts the rotation angle of the throttle valve into a voltage value and converts the A / D converter. There are analog and electric throttle sensors that divide the opening of the throttle valve by using it. In the present invention, both throttle sensors are provided and used by switching, but in an ordinary apparatus, only one of them may be used. The throttle sensor outputs a signal obtained by dividing the opening of the throttle valve by 16 from four signal lines. The fully closed state is θ0, and the fully open state is θ15. The range between θ0 and θ15 is θ1 to θ14.

The neutral start switch 27 detects the position of the shift lever, and includes a D (drive) range switch, an L (low) range switch, a 2 (second) range switch, a 3 (third) range switch, and an N (neutral) range switch. , R (reverse) range switch and P
(Parking) Has a range switch, D, L, 2,3, N, R, P
Each range of is detected.

The overdrive cut switch 31 is a switch operated by the driver and prohibits overdrive.
This is a switch for setting permission. Instead of the overdrive cut switch, for example, an interface may be provided for inputting an overdrive cut signal from the constant speed traveling device for preventing an increase in speed during constant speed traveling by the constant speed traveling device.

The idle switch 32 is a sensor for detecting an idle state of the engine, and its contact is turned on at the time of idling (in this embodiment, the throttle opening is 1.5% or less).

The brake switch 33 detects whether the brake is on or off.

Each output terminal of the central processing unit CPU has a clutch C0
Solenoid valve 41 for control, solenoid valve 42 for clutch C2 control, solenoid valve 43 for brake B0 control, solenoid valve 44 for brake B1 control, solenoid valve 45 for brake B2 control, solenoid valve 46 for prohibiting low / reverse shift, lockup Control solenoid valve 47
And a line pressure control solenoid valve 48 is connected. In FIG. 3, the output interface or driving device of each lamp and solenoid is omitted for simplicity. Each of these solenoid valves is controlled by a central processing unit CPU.

The central processing unit CPU has internal memories such as RAM and ROM, a timer, and a register. When the ignition switch is turned on and voltage is supplied to the central processing unit CPU, the main routine shown in FIG. 4 is executed. Begin to.

FIG. 4 is a flowchart of a main routine of the central control unit CPU, a vehicle speed sensor interrupt, a turbine rotation sensor interrupt, an engine rotation sensor interrupt, and a periodic interrupt.

(Main Routine) When the central control unit CPU is started, first, the setting of the input / output direction of each input / output port, the initialization of each memory, and the setting of the presence / absence of an interrupt are performed (step 5)
0).

Thereafter, an input / output reading routine is executed to read the state of each sensor and switch connected to the input, remove noise, and set data according to the state of each sensor and switch (step 51).

Next, a rotation speed calculation processing routine is executed to calculate the vehicle speed, the turbine rotation speed, and the engine rotation speed (step 52).

The calculation of the engine speed NE is performed by the following equation. still,
Since the output from the engine rotation sensor has a high frequency,
It is calculated after dividing by 8.

Here, nEi: the number of revolutions of the engine by the current pulse, TEi: the time count up to the edge of the first pulse exceeding 10 mS from the previous pulse, PCi: the number of pulses in TEi, 8 × 10 ^-6 : the detection time The minimum unit (8 μS).

The calculation of the turbine rotational speed NT is performed by the following equation. still,
Since the output from the turbine rotation sensor has a high frequency,
It is calculated after dividing by 4.

Here, nTi: the number of revolutions of the turbine by the current pulse, TTi: the time count up to the edge of the first one pulse exceeding 10 mS from the previous pulse, and PCTi: the number of pulses in TTi.

 The calculation of the output shaft rotation speed N0 is performed by the following equation.

Here, n0i: the number of revolutions of the output shaft by the current pulse, T0i: the time count up to the edge of the first one pulse exceeding 10 ms from the previous pulse, and PC0i: the number of pulses in T0i.

The first calculation of the output shaft rotational speed N0 after the vehicle stops (determined in the regular interrupt routine described later) And

Since the gear ratio between the output shaft and the axle and the radius of the wheels are obtained in advance, the vehicle speed can be obtained from the output shaft rotation speed N0.

 The vehicle acceleration AG is obtained by the following equation.

The first calculation after the vehicle stops is And When N0i <N0 (i-1), AG is set to the maximum value (￥
FF).

Next, a line pressure control / shift control routine is executed,
The setting and control of the line pressure, the setting of the control mode, and the shift determination are performed (step 54). The line pressure set value is set based on the throttle opening and the turbine speed. The line pressure solenoid is duty driven according to this set value.

In the shift control, the presence or absence of a shift determination is determined based on a throttle opening, a vehicle speed, and a shift diagram created in advance at the current shift stage.

When the above processing is completed, next, it is determined that the shift is possible in the line pressure control / shift control routine, and when the shift is not currently being performed, the shift processing routine is executed.
A shift process is performed.

Next, a lock-up determination routine is executed. If there is a change in lock-up, a lock-up processing routine is executed, and lock-up processing is performed. here,
Engine brake control is performed as part of the lockup process. Here, when the throttle opening is fully closed (idle contact is on) and the vehicle speed is higher than the set vehicle speed (15 km / h), regardless of the shift speed, the lock-up solenoid is turned on and directly connected while the engine speed <turbine speed. Apply the engine brake. After the elapse of 0.6 seconds from the state where the idle contact is off or the engine speed> turbine speed, a shift determination is made based on the current speed.

Next, a squat control / oil temperature control routine is executed,
Scoot control to temporarily increase the gear to 3rd when the vehicle deviates from the neutral range when the vehicle stops and cushion the shock, and oil temperature control to change the gear when the hydraulic oil of the automatic transmission is at an abnormal temperature Is performed (step 61).

Next, fail-safe control is performed, and a fail-safe process is performed (step 64).

Finally, an output control routine is executed, and output control of the solenoid and the like is performed (step 65).

(Interrupt routine) The outputs of the output shaft rotation sensor, turbine rotation sensor, and engine rotation sensor are each connected to the interrupt input terminal of the central processing unit CPU. Each time the voltage level of the interrupt terminal changes, the output shaft rotation sensor An interruption routine, a turbine rotation sensor interruption routine, and an engine rotation sensor interruption routine are executed.

In the output shaft rotation sensor interruption routine, first, the time at the time of interruption is read from a timer, and here, a calculation flag for calculating the output shaft rotation speed is turned on. Next, a failure of the turbine rotation sensor and the engine rotation sensor is determined. (Steps 66-68). This failure determination is made by comparing the output shaft speed with the turbine speed and the engine speed.

In the turbine rotation sensor interruption routine, first, the time at the time of interruption is read from a timer, and when the interruption is counted four times in order to divide the input pulse by four, the operation flag for calculating the turbine rotation speed is turned on.
Then, a failure of the engine rotation sensor and the output shaft rotation sensor is determined. (Steps 69-71). This failure determination is made by comparing the turbine speed with the engine speed and the output shaft speed.

The frequency division may be performed by installing a frequency dividing circuit between the central control unit CPU and the rotation sensor.

In the engine rotation sensor interruption routine, first, the time at the time of interruption is read from a timer, and when an interruption is counted eight times in order to divide the input pulse by eight, a calculation flag for calculating the engine rotation speed is turned on.
Then, a failure of the output shaft rotation sensor and the turbine rotation sensor is determined. (Steps 72-74). This failure determination is made by comparing the engine speed with the output shaft speed and the turbine speed.

The frequency division may be performed by installing a frequency dividing circuit between the central control unit CPU and the rotation sensor.

The central control unit CPU has a periodic interrupt that is generated every time a predetermined time elapses. In this embodiment, 4 ms
A periodic interrupt routine is executed each time. here,
First, various timers used for control are subtracted (step 75). Next, it is determined that the vehicle is stopped (step 76). In this embodiment, the vehicle stop speed Nstop = 144
Stop the vehicle below rpm (about 3km). When there is no pulse with an input frequency Tstop = 23.13 mS or more to the central control unit CPU, the vehicle is stopped.

Hereinafter, the details of the output control will be described based on a flowchart.

(Output Control Routine) FIG. 5 is a flowchart of the output control routine.

During shifting permission flag is ON, sets the time and upshift and power-off (θ <θ ₂ or idle switch ON) times power-off upshift flag of R-range, clear the shift permission flag, sets the shift flag (Steps 292, 295, 296). Upshift in a range other than the R range and the power-on (θ ≧ θ ₂₎ sometimes set a power-on upshift flag, clears the shift permission flag, sets the shift flag (step 293,
295,296). When downshifting outside the R range, the downshift flag is set, the shift permission flag is cleared,
The shifting flag is set (steps 294, 295, 296).

When the shift permission flag is on or the shifting flag is on, the downshift routine is executed if the downshift flag is on, and the power off upshift routine is executed if the power off upshift flag is on. If the upshift flag is on, a power-on upshift routine is executed (297-303).
If the duty ratio SD OFF of the release side solenoid valve set in each shift routine is not less than 0%, the release side solenoid valve is controlled with the duty ratio SD OFF (steps 304 and 305). If the duty ratio SD ON of the engagement side solenoid valve set in each shift routine is not 100% or more, the engagement side solenoid valve is controlled with the duty ratio SD ON (step 30).
6,307). The engagement side solenoid valve and the release side solenoid valve are set for each shift. The solenoid valve for each shift is shown in the table below.

During the reverse shift, the engagement side and release side solenoid valves are reversed.

Thereafter, if it is necessary to change another solenoid valve, for example, a solenoid valve for lock-up control, an output is issued so as to drive the solenoid valve, and thereafter, the process returns to the main routine.

(Power-On Upshift Routine) FIGS. 6a, 6b and 6c are flowcharts of the power-on upshift routine.

In this process, the timer counter is usually set from 0 to 1,
The numbers are changed in the order of 2,.

In this routine, first, the engine speed NE is monitored, and it is determined whether or not the engine speed NE has reached a predetermined value REND (step 452). REND is the engine speed that will reach after the end of the shift, and is obtained as (next shift stage) × (vehicle speed) at the time of shift determination, although not shown. Therefore, since NE ≠ REND at the start of shifting, the process proceeds to step 457. If NE = REND in the shifting process, the shift ending process is performed in steps 453 to 456. During this shifting process, the timer counter is set to 0 (step 454), so that at the start of shifting, steps 458 and thereafter are always executed first.

(1) Timer counter = 0 Since the timer counter is 0 immediately after the shift is determined,
Steps 458 to 466 are executed. First, the timer counter is set to 1 for the next processing (step 458), and TON is set.
The timer is set and the TON timer starts (step 459). In the TON timer, a time period from the shift determination to the engagement of the engagement side solenoid valve by 100% is set.

Next, the value of the TOFF timer is set to a value obtained by adding a value ΔTOFF obtained from an engine rotation rise peak value RTOP during the previous shift to a value VOFF set by performing a map search according to the shift condition. (Step 460). The value VOFF is a basic time until the solenoid valve on the release side is released, and the value Δ
TOFF is a correction value. After the TOFF timer is set, the TOFF timer is decremented by a periodic interrupt, and thus starts at this time. Then, the memory that is the memory for control
Set 0 to TOP, OVC, OVL, ΔROV and ROVC. Then, the current engine speed, that is, the engine speed at the start of the control, is set in the memory ROV (steps 461 to 461).
66).

Thereafter, the process returns to the main routine via the output control routine.

(2) Timer counter = 1 Timer counter = 1 when timer counter = 0
Therefore, when the power-on upshift routine is executed next, steps 468 to 476 are executed (step 467).

Here, it is determined whether the TON timer started when the timer counter is 0 has expired, and if it has expired, the TON timer is cleared, the TUP timer is started, and the memory SD ON is set to 100%. (Steps 469-471). As described above, the value of the memory SD ON is handled as the duty ratio of the solenoid valve on the engagement side during output control. Therefore, by this process, the duty ratio of the solenoid valve on the engagement side is 100%, that is, completely engaged. For the TUP timer, use the engaging solenoid valve.
100% engagement time is set.

Next, it is determined whether the TUP timer has expired. If the TUP timer has expired, clear the TUP timer, set the value searched from the map to the Tg1 timer, start the Tg1 timer, set the timer count to 2, and assign the value SD HOLD to the memory SD ON (Steps 473-476). SD HOLD is a duty ratio corresponding to the highest level of hydraulic pressure at which the manual valve does not start operating. By adding this duty ratio, the responsiveness at the next operation is improved.

As described above, from the end of the TON timer to the end of the TUP timer, the duty ratio of the engagement side solenoid valve becomes 100%. After the end of the TUP timer, the duty ratio of the engagement side solenoid valve becomes the value SD HOLD. In the Tg1 timer, a limit time for fixing the duty ratio of the engagement side solenoid valve to the value SD HOLD when the engine speed does not increase during gear shifting is set.

(3) Timer counter = 2 Since the timer counter is set to 2 at the end of the TUP timer, when the power-on upshift routine is executed next, steps 478 to 483 are executed (step 478).
477).

Here, it is determined whether the TOFF timer started when the timer counter is 0 has expired, and if it has expired, the TOFF timer is cleared and the memory SD OF
F is set to 0%, the current engine speed is set in the memory ROV, the timer counter is set to 3, and the flag FRU is set.
The SH is turned off (steps 478 to 483). This gives T
During the execution of the OFF timer, the solenoid valve on the release side retains the duty ratio before the shift is determined, and after the end of the TOFF timer, the solenoid valve is completely released at 0%.

(4) Timer counter = 3 Since the timer counter is set to 3 at the end of the TOFF timer, when the power-on upshift routine is next executed, Step 485 and the subsequent steps are executed (Step 484).

First, it is checked whether or not the engine speed has changed from the value ROV (step 485). At the start of the timer counter = 3, the value ROV is the engine speed at the end of the TOFF timer, ie, when the release solenoid valve is released. In the present embodiment, since the input of the engine speed is divided by 8, the value of the engine speed NE may not change during one round of the main routine. At this time, most of the processing is skipped by step 485. If there is a change in the engine speed, the value OVC is incremented by 1, and a value obtained by subtracting the value ROV from the current engine speed is added to the value ΔROV, and the value ROV is updated to the current engine speed (step 487,489-490). The value ΔROV is the difference between the engine speed before the engine speed changes and the current engine speed.

Next, it is checked whether ΔROV is higher than 20 rpm. ΔROV
Is higher than 20 rpm, .DELTA.ROV / OVC is substituted for the value AGL RUSH, and .DELTA.TOFF, VD1, and AGL1 are calculated from the value AGL RUSH (steps 492 to 494). VD1 and AGL1 are values representing the control time and control amount of the engagement side solenoid valve. Value AGL
RUSH divides the difference between the engine speed before the engine speed changes and the current engine speed by the number of updates of the value ΔROV, that is, the value corresponding to the difference between the time before the engine speed changes and the current time. It is a value corresponding to the rising speed of the engine rotation. Release both the release side solenoid valve and the engagement side solenoid valve (the duty of the engagement side solenoid valve is SD HOLD. This is the duty ratio corresponding to the maximum non-operating pressure, so the engagement side solenoid valve is released. When the load on the vehicle is large, the rising speed of the engine rotation is fast, and when the load on the vehicle is small, the rising speed of the engine rotation is slow. Therefore, the load on the vehicle can be estimated from the size of AGL RUSH. Since the values ΔTOFF, VD1 and AGL1 used for shifting are changed according to the value corresponding to the load of the vehicle, the shifting can be performed in accordance with the load of the vehicle.

Thereafter, SD1 which is an engagement ratio at the start of engagement is obtained from the throttle opening. This is obtained from the graph of FIG. 12 showing the value of SD1 with respect to the throttle opening (step 506). Thereafter, the duty of the engagement side solenoid valve is set to the value SD1 (step 507). Also, from the map,
Search for TD1 and ΔAGL1 (step 508). next,
The value VD1 is read from the map according to the running state (step 509). Then, the value obtained by adding ΔTD1 to VD1 is used as the timer T
Set to D1, start timer TD1, and AGL1
Is corrected by adding ΔAGL1 to (steps 509 and 511). Thereafter, the timer counter is set to 4 (steps 510 to 51).
2).

When the timer count = 3, if the Tg1 timer ends before the engine speed has increased by 20 rpm or more from the engine speed at the time of release of the release side solenoid valve, the Tg2 timer is started and the timer count is set to 9 (step 497). ~ 499). Normally, in the case of an upshift, when both the release side solenoid valve and the engagement side solenoid valve are released, no load is applied to the engine, so that the engine rotation increases. However, if the engine speed does not increase by 20 rpm or more within the predetermined time, an exception process of timer count = 9 (steps 544 to 547) is performed.

(5) Timer counter = 4 When the engine speed increases by a predetermined value, the timer counter is set to 4, so that when the power-on upshift routine is next executed, step 515 and subsequent steps are executed (step 514). ).

If the TD1 timer has not expired, the duty ratio of the engagement side solenoid valve is incremented by a value ΔSD (AGL1) based on the value AGL1 every time the timer counter = 4 (step 520).

Thereafter, when the TDRP timer expires, the value of the memory ROVC is increased by one, and the maximum value R of the engine speed is increased.
The value obtained by subtracting the current engine speed from TOP is stored in ΔROV. Then, if the value of the memory ROVC is not 4, substitute 40 ms into the TDRP timer and start again to clear ΔTD3 and ΔAGL3 (steps 524 and 52).
8,529). The value of the memory ROVC becomes 4, ie, 4 times TDRP
When the timer has finished running (approximately 20m from when the engine speed begins to fall until the first TDRP timer starts running)
s, since the first TDRP timer is 20 ms and the last three times are 40 ms, 160 ms have elapsed in total), ΔROV is divided by 16, and ΔROV is updated by the divided value (thus, ΔROV is the engine speed of 10 ms). Shows how much has dropped on average), TDRP
The timer is cleared, and ΔTD3 and ΔAGL3 are calculated from the value of ΔROV (steps 524 to 527).

When the TD1 timer ends when the timer counter is 4, the TD1 timer is cleared, the TD2 timer starts, AGL2 is obtained, and the timer counter becomes 5 (steps 515 to 520).

(6) Timer counter = 5 When the TD1 timer ends, the timer counter is set to 5, so that when the power-on upshift routine is executed next, steps 531 and thereafter are executed (step 530).

If the TD2 timer has not expired, the duty ratio of the engagement side solenoid valve is incremented by the value ΔSD (AGL2) based on the value AGL2 every time the timer counter = 5 (step 536). After this, the timer counter =
The process jumps to step 521 of step 4 and performs the same processing. That is,
When the TDRP timer runs four times (160 ms after the engine speed starts decreasing) four times before the TD2 timer ends after the engine speed starts decreasing, ΔTD3 and ΔAGL3 are calculated.

When the TD2 timer ends, the TD2 timer is cleared and the timer counter is set to 6 (steps 532 and 53).
3). Next, the value VD3 is searched from the map according to the traveling state at that time. Then, a value obtained by adding ΔTD3 to the value VD3 is set in the timer TD3, and the timer TD3 starts (steps 534 and 535). The value of ΔTD3 is 0 within 160 ms after the engine speed starts to decrease, and becomes a value obtained from the average decrease number ΔROV during 160 ms after 160 ms.

(7) Timer counter = 6 When the TD2 timer ends, the timer counter is set to 6, so that when the power-on upshift routine is executed next, steps 538 and thereafter are executed (step 537).

When the TD3 timer has not expired, the duty ratio of the engagement side solenoid valve is incremented by the value ΔSD (AGL3) based on the value AGL3 every time the timer counter = 6 (step 542).

When the TD3 timer ends, the TD3 timer is cleared, the timer counter becomes 7, and the value of AGL4 is calculated (steps 538 to 541).

(8) Timer counter = 7 When the TD3 timer ends, the timer counter is set to 7, so that when the power-on upshift routine is next executed, step 548 is executed. Here, the duty ratio of the engagement side solenoid valve is added by a value ΔSD (AGL4) based on the value AGL4.

(9) Timer counter = 9 If the engine counter does not increase by more than 20 rpm within a predetermined time when the timer counter is 3, an exception process of timer count = 9 is performed. Here, the duty ratio of the engagement side solenoid valve is added by a value ΔSD (AGL3) based on the value AGL3 until the end of the Tg2 timer. When the Tg2 timer ends, the Tg2 timer is cleared, and the duty of the engagement side solenoid valve is reduced. 100% and the engaged solenoid valve is fully engaged.

(10) Completion of power-on upshift When the engine speed reaches the engine speed REND that will reach after the end of the gear shift during the processing described above, the shifting flag is cleared, the timer counter becomes 0, and the engagement side The duty of the solenoid valve is set to 100%, the Tg2 timer is cleared, and the control of the power-on upshift ends.

FIG. 9 is a time chart showing the flow of the processing described above. The duty of the engagement side solenoid valve becomes 100% after TON seconds from the shift determination, and becomes SD HOLD% after TUP seconds have elapsed. And when the engine speed rises more than 20rpm, it becomes SD1%. After that, it rises at the slope AGL1 for TD1 second, then rises at the slope AGL2 for TD2 seconds, rises at the slope AGL3 for TD3 seconds, and finally rises at the slope AGL4. If the engine speed reaches REND during this time, the duty of the engagement side solenoid valve is set to 100%, and the control is terminated. The release solenoid valve becomes 0% after TOFF from the shift determination.

The value SD1 is obtained from the throttle opening as a substitute for the engine load. When the throttle opening is high, the engine load is high, and when the throttle opening is low, the engine load is low. Here, when the throttle opening is high, the value SD1 is set low, and when the throttle opening is low, the value SD1 is set high. Therefore, when the load is high, the value SD1 becomes low, and the engagement of the clutch or brake on the engagement side is performed gradually, so that the shock is reduced. SD at low load
1 becomes higher, and the engagement side clutch and brake are quickly engaged. Therefore, the responsiveness is improved at a low load.

(Power Off Upshift Routine) FIGS. 7a, 7b and 7c are flowcharts of the power off upshift routine.

The processing in this is performed for each value of the timer counter as in the power-on upshift routine.

(1) Timer counter = 0 Since the timer counter is set to 0 at the end of any shift, the timer counter is 0 at the time of shift determination.

Here, after rewriting the value of the timer counter to 1, the TUP timer is set (steps 377 and 378).
Next, a value VOFF is searched from the map according to the traveling state. Then, the value obtained by adding ΔTOFF to VOFF is used as the timer T
The timer is set to OFF and the timer TOFF is started (step 379). Further, the Tgd timer is started, the duty of the engagement side solenoid valve is set to 100%, the memories OVC and OVL are set to 2, and the memories ROVC and ΔROV are set to 0 (steps 380 to 385).

(2) Timer counter = 1 Timer counter = 1 when timer counter = 0
Is set, so that the steps after step 387 are executed (step 386).

First, check if the TUP timer has expired,
If it has been completed, the TUP timer is cleared and the duty of the engagement side solenoid valve is set to SD HOLD (step 387).
389).

Also, it is checked whether the TOFF timer has expired. If the timer has expired, the TOFF timer is cleared, the duty of the release solenoid valve is set to 0%, the timer counter is set to 2, and the engine speed is substituted for ROV ( Steps 390-394).

(3) Timer counter = 2 When the TOFF timer ends, the timer counter = 2.

First, when the engine speed has not been updated at the time of calculation, the process jumps to step 413. When the engine speed increases, 2 is substituted for OVL, and the value of OVC is subtracted by 1 (steps 407 and 408). When the value of OVC becomes 0, the duty ratio of the release side solenoid valve is set to 100%, and the release side is engaged again. Then, the value of the TOV timer is read from the map, the TOV timer is started, and ΔTOFF is read from the map (steps 409 to 412).

If the engine speed is not increasing but decreasing and the speed is not fast, the engine speed is substituted for ROV (step 405).

If the engine speed drops rapidly, it is checked whether OVL is 2. If OVL is 2, OVL is set to 1 and the engine speed is substituted for ROV (steps 401 and 402). If OVL is not 2, a value of ΔTOFF is searched from the map, and a value obtained by adding a minus value to the value is set as ΔTOFF (step 403).
Then, the value of OVL is subtracted by 1 (step 404). In this case, OVC is set to 2. Note that the OVL is
Is negative, step 399 to step 406 are skipped in step 298.

Next, if the TOV timer has expired, the TOV timer is cleared and the duty ratio of the release side solenoid valve is set to 0.
% (Steps 413 to 415).

Then, check whether the Tgd timer has expired, if it has expired, clear the Tgd timer, start the 40 ms TROV timer and the TD1 timer set according to the running state, read the value of AGL1, read the ROV And the timer counter is set to 3 (step
416-422).

If the engine speed rises after the release solenoid valve is released by releasing the release solenoid valve, the release solenoid valve is engaged again for the TOV time, and at the same time, the TOFF time for the next shift is extended. Further, if the drop of the engine rotation is significant two consecutive times after releasing the release-side solenoid valve, a process of shortening the TOFF time at the next shift is performed.

(4) Timer counter = 3 When the Tgd timer ends, the timer counter becomes 3.

Here, we check whether the TD1 timer has expired,
If it has been completed, the timer counter is set to 4, the TD1 timer is cleared, the TD2 timer set according to the running state is started, and AGL2 is set (steps 424 to 42).
8). In addition, every time the timer counter = 3, the duty ratio of the engagement side solenoid valve is set to a value Δ based on the value AGL1.
SD ON (AGL1) is added (step 429).

Thereafter, it is determined whether the TROV timer has expired, and if it has expired, (ROV-engine speed) is added to ΔROV (step 431). Then, the engine speed is substituted for ROV, and 1 is added to ROVC (steps 432, 433). Until the ROVC becomes 4, the TROVC timer is set to 40 ms (steps 434 and 435). If ROVC is 4, ΔROV
Is substituted for ΔROV / 16, and ΔTD3 and ΔAGL3 are obtained from the ΔROV (steps 436 and 437). Since ΔROV is a value obtained by dividing the decrease value from the engine speed at the end of the Tgd timer 160 ms after the end of the Tgd timer by 16 by 16, the average decrease value during 10 ms, that is, the average descending speed is obtained.

(5) Timer counter = 4 When the TD1 timer ends, the timer counter becomes 4. Here, ΔSD ON (AGL
2) The duty ratio of the engagement side solenoid valve is increased at a time (steps 439, 444).

When the TD2 timer ends, the TD2 timer is cleared and the timer counter is set to 5 (steps 440 and 441). Next, the values VD3 and AGL3 are searched from the map according to the traveling state. Then, the value obtained by adding ΔTD3 to VD3 is used as the timer TD3
And start timer TD3. Also, AGL
Then, ΔAGL3 is added to 3 for correction (steps 442 and 443).

(6) Timer counter = 5 When the TD2 timer ends, the timer counter becomes 5. The processing here is the same as the processing of the timer counter of power-on upshift = 6, and the duty ratio of the engagement side solenoid valve is increased by ΔSD ON (AGL3) until the TD3 timer ends.

(7) Timer counter = 6 When the TD3 timer ends, the timer counter becomes 6. The processing here is the same as the processing of the timer counter of power-on upshift = 7, and increases the duty ratio of the engagement side solenoid valve by ΔSD ON (AGL4).

(8) Completion of power-off upshift When the engine speed reaches the engine speed REND that will reach after the end of the gear shift during the process described above, the gear shift flag is cleared, the TD3 timer is cleared, and the engagement side solenoid valve is cleared. Is set to 100% (steps 386 to 370). Then, the timer counter is set to 0, 2 is substituted for OVC and OVL, and 0 is substituted for ROVC and ΔROV, and the control of the power-off upshift ends.

FIG. 10 is a time chart showing the flow of the processing described above. The duty ratio of the solenoid valve on the release side is T
0% after OFF seconds. However, if the engine speed rises after TOFF seconds, the duty ratio will again be 10 TOV seconds.
0%. The duty ratio of the engagement side solenoid valve is fixed at 100% for TUP seconds from the shift determination, and then becomes SD HOLD% until Tgd seconds after the shift determination. During the subsequent TD1 second, it rises at the slope AGL1, and similarly, during the subsequent TD2 second, the slope AGL
It rises by 2 and rises by AGL3 for 3 seconds in TD. After that, it keeps rising at the slope AGL4. Engine speed is REND
, The duty ratio is fixed at 100%, and the control ends.

(Downshift Routine) FIGS. 8a and 8b are flowcharts of the downshift routine.

The processing in this is performed for each value of the timer counter as in the power-on upshift routine.

(1) Timer counter = 0 Since the timer counter is set to 0 at the end of any shift, the timer counter is 0 at the time of shift determination.

Here, after rewriting the value of the timer counter to 1, the TUP timer is set (steps 315 and 316).
Next, a value VOFF is searched from the map according to the traveling state. Then, the value obtained by adding ΔTOFF to VOFF is used as the timer T
The timer is set to OFF and the timer TOFF is started (step 317). Next, substituting the engine speed into ROVTOP,
The ROV is read from the memory, and the ROV is updated with a value obtained by adding the engine speed to the ROV (step 318). Also T
The gd timer is started, the duty of the engagement side solenoid valve is set to 100%, and OVC is set to 0 (steps 319 to 320).

(2) Timer counter = 1 Timer counter = 1 when timer counter = 0
, So that the steps from step 322 are executed (step 321).

First, check if the TUP timer has expired,
If completed, the TUP timer is cleared and the duty of the engagement side solenoid valve is set to SD HOLD (step 322).
~ 324).

Also, it is checked whether the TOFF timer has expired, and if it has expired, the TOFF timer is cleared, and the duty of the solenoid valve on the release side is set to 0% (step
325-327).

Next, it is checked whether or not the engine speed has become larger than the value ROV. If it is, the current time is stored in the time memory (A).
And assigns 2 to OVC, and sets the duty ratio of the engagement side solenoid valve to SDST (steps 329 to 332).
Next, check whether OVC is 0 or not. When OVC is not 0, the engine speed is compared with the value ROVTOP. If the engine speed is larger than ROVTOP, the engine speed is substituted into ROVTOP, and OVC is set to 2 (steps 334, 339, 340). If the engine speed is smaller than ROVTOP, the value of OVC is subtracted by 1 (step 335). When the value of OVC becomes 0, the value obtained by subtracting the time stored in the time memory (A) from the current time is set as ΔTOFF, and the duty ratio of the engagement side solenoid valve is set as SD HOLD. (Steps 336-338).

Then, when the Tgd timer expires, the Tgd timer is cleared, the TD1 timer is started, and after searching AGL1, the timer count is set to 2 (step 34).
1-345).

The memory OVC is set to 0 at the start of a shift, and becomes 2 when the engine speed increases by a predetermined value or more than at the start of the shift. The value of the memory OVC remains at 2 when the engine speed is increasing, and is decremented by 1 when the engine speed reaches a peak and stops increasing. When the engine speed does not increase continuously for two times, the value becomes zero. The duty ratio of the solenoid valve on the engaging side is SD S between the time when the engine speed rises by a predetermined value or more than the time when the shift is started and the time when the engine speed no longer rises two consecutive times.
Changed to T%. Further, the time from when the engine speed increases by a predetermined value or more than when the shift is started to when the engine speed does not continuously increase twice is stored in ΔTOFF. Since this ΔTOFF is added to the time until the release solenoid valve is released at the next shift, the sudden increase in the engine speed is unlikely to occur at the next shift.

(3) Timer counter = 2 When the Tgd timer ends, the timer counter = 2.

Here, we check whether the TD1 timer has expired,
If completed, the TD1 timer is cleared, the TD2 timer is started, AGL2 is set, and the timer counter is set to 3 (steps 347 to 351). Also, the timer counter =
For each process of step 2, the value ΔSD ON (AGL1) based on the value AGL1 is added to the duty ratio of the engagement side solenoid valve (step 352).

(4) Timer counter = 3 When the TD1 timer ends, the timer counter becomes 3. Here, ΔSD ON (AGL
2) Increase the duty ratio of the engagement side solenoid valve at a time. (Step 359).

When the TD2 timer ends, the TD2 timer is cleared and the TD3 timer set according to the running state is started. Further, the value AGL3 is searched from the map according to the running state, and the timer counter is set to 4 (steps 355 to 3
58).

(5) Timer counter = 4 When the TD2 timer ends, the timer counter becomes 4. The processing here is the same as the processing of the timer counter of power-on upshift = 6, and the duty ratio of the engagement side solenoid valve is increased by ΔSD ON (AGL3) until the TD3 timer ends.

(6) Timer counter = 5 When the TD3 timer ends, the timer counter becomes 5. The processing here is the same as the processing of the timer counter of power-on upshift = 7, and increases the duty ratio of the engagement side solenoid valve by ΔSD ON (AGL4).

(7) End of downshift When the engine speed reaches the engine speed REND which will be reached after the end of the gear shift during the above-described processing, the shift flag is cleared, the TD3 timer 1 is cleared, and the engagement side solenoid valve is turned off. The duty ratio is set to 100% (steps 310 to 312). Then, the timer counter is set to 0, and the downshift control ends.

FIG. 11 is a time chart showing the flow of the downshift process described above. The duty ratio of the solenoid valve on the release side is set to 0% after TOFF seconds. The duty ratio of the engagement side solenoid valve is 100
%, Then SD HOLD until Tgd seconds after shifting
%become. However, when the engine speed increases by a predetermined value or more, the duty ratio of the engagement side solenoid valve is increased to SD ST% until the engine speed reaches a peak. During the subsequent TD1 second, the gradient rises at the gradient AGL1, similarly, at the subsequent TD2 seconds, the gradient AGL2 increases, and similarly, at TD3 seconds, the gradient AGL3 increases. After that, it keeps rising at the slope AGL4.
When the engine speed reaches REND, the duty ratio becomes 100%
And the control ends.

〔The invention's effect〕

As described above, according to the present invention, at the time of shifting, after the fluid pressure switching unit is instructed to release the clutch or brake on the release side, the engagement of the clutch or brake on the engagement side is set by the setting unit ( Engage by the engagement start ratio (SD1) set in step 506), and then
The fluid pressure switching means is instructed to gradually increase the engagement ratio (step 520) (step 307).

 The load detection of the vehicle is performed by load detection means (26).

The setting of the engagement-side clutch or brake at the start of engagement is set high by a setting means (step 506, FIG. 12) at low load and low at high load.

Therefore, when the load on the vehicle is low, the engagement is quickly performed, the response is improved, and the transmission efficiency is improved. At the time of a high load, the engagement is gradually performed, so that the shock is reduced. In addition, since the shock is smaller at the time of low load than at the time of high load, the magnitude of the shock can be suppressed as a whole.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the structure of an automatic transmission of an electronically controlled automatic transmission according to an embodiment of the present invention. FIG. 2 shows a hydraulic circuit for driving the automatic transmission of FIG. FIG. 3 shows an electronic control circuit for controlling the hydraulic circuit of FIG. FIG. 4 is a flowchart of a CPU main routine, a vehicle speed sensor interrupt, a turbine rotation sensor interrupt, an engine rotation sensor interrupt, and a periodic interrupt of the electronic control circuit of FIG. FIG. 5 is a flowchart of an output control routine of the CPU of the electronic control circuit of FIG. 6a, 6b and 6c are flowcharts of the power-on upshift routine in the output control routine of FIG. FIGS. 7a, 7b and 7c are flowcharts of the power-off upshift routine in the output control routine of FIG. 8a and 8b are flowcharts of a downshift routine in the output control routine of FIG. FIGS. 9, 10, and 11 are time charts at the time of power-on upshift, power-off upshift, and downshift in the embodiment of the present invention. FIG. 12 is a graph for obtaining the ratio SD1 at the start of engagement from the throttle opening in the embodiment of the present invention. CPU: Central processing unit, 20: Battery, 21: Ignition switch, 22: Constant voltage power supply, 23: Engine rotation sensor, 24: Turbine rotation sensor, 25: Output shaft rotation sensor, 26: Throttle sensor, 27 Neutral start switch, 31 Overdrive cut switch, 32 Idle switch, 33 Brake switch, 41 Solenoid valve for clutch C0 control, 42 Solenoid valve for clutch C2 control, 43 …… Brake B0 control solenoid valve, 44 …… Brake B1 control solenoid valve, 45 …… Brake B2 control solenoid valve, 46 …… Low, reverse prohibition solenoid valve, 47 …… Lock-up control solenoid valve , 48 …… Solenoid valve for line pressure control, B2 …… 1st and Rev brake, C2 …… Die Recto clutch, B1 ... Second brake, C0 ... OD clutch, B0 ... OD brake, C1 ... Forward clutch, 600 ... Turbine shaft, 601 ... OD planetary gear, 605 ... Output shaft, 606,616 ... 1 Way clutch, 607… Overdrive mechanism, 608… Gear speed change mechanism, 609,617,618 …… Carrier, 610,619,621 …… Planetary pinion, 611 …… Input shaft, 612 …… Sun gear, 613 …… Housing, 614 …… Intermediate shaft, 615… Sun gear shaft, 701… Sump, 702… Hydraulic pump, 703… Pressure adjustment valve, 704 …… Line pressure oil passage, 705,706,707,708,709… Manual valve, 710 …… Valve, 711… Shift valve, 712 ... Lock-up control valve.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-103041 (JP, A) JP-A-62-106159 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 59/00-63/28

Claims (3)

(57) [Claims] A clutch and a brake which are operated by application of a fluid pressure are provided.
An automatic transmission that changes a gear ratio by disengagement, a fluid pressure switching unit that controls application of fluid pressure to the clutch and the brake, and a drive unit that drives the fluid pressure switching unit according to a running state of a vehicle.
An electronic control unit that changes engagement / disengagement of the clutch and the brake; a load detection unit that detects a load on a vehicle; and an engine speed detection that detects an engine speed. Means, setting means for setting the ratio setting at the start of engagement of the clutch or brake on the engagement side to be high at the time of low load and low at the time of high load. By detecting the operation of the disengagement side clutch or brake in response to the increase in the engine speed, the hydraulic pressure of the engagement side clutch or brake is set to increase, and the disengagement of the release side clutch or brake is performed by the fluid pressure switching means. After the instruction is given, the engagement of the clutch or brake on the engagement side is engaged by the engagement start ratio set by the setting means. After gradually directs the fluid pressure switching means so as to increase the engagement ratio, the electronic control automatic transmission. 2. The electronically controlled automatic transmission according to claim 1, wherein the load of the vehicle detected by said load detecting means is a throttle opening. 3. The electronically controlled automatic transmission according to claim 1, wherein the ratio setting at the start of engagement is performed only during an upshift at a high throttle opening.