JPS6118528A - Controller for internal-combustion engine for automatic transmission - Google Patents

Abstract

PURPOSE:To soften the sharp starting-up of the output-shaft torque of an automatic transmission after the completion of engagement accompanied by starting- up by decreasing the output torque of an internal-combustion engine after the completion of the engagement from a frictional engagement apparatus for high- speed stage to a frictional engagement apparatus for low-speed stage. CONSTITUTION:A hydraulic control circuit 30 is equipped with a solenoid valve 32, and an EFI computer 38 calculates the fuel injection amount and the ignition timing and controls an engine 40. Said computer 38 receives an input signal from a switch 42 for detecting that the piston of the accumulator of a frictional engagement apparatus for high-speed stage is set at an oil discharge position. A standard time is detected on the basis of the detection signal of the switch 42 or the speed-change signal supplied from an ECT computer 36, and an advance amount control means 74 as engine output torque increasing and decreasing means decreases the advance amount in relation to the lapse time measured by a timer 72, and an ignition coil 76 is controlled by a means 74.

Description

TECHNICAL FIELD The present invention relates to an internal combustion engine control device for an automatic transmission vehicle.

Prior art When a downshift is performed during power-on, that is, during a period when positive 1-lux is being transmitted from the engine to the drive wheels, the (rotating member of) the frictional engagement device N for low speed gears substantially ends its engagement. (particularly when the low-speed frictional engagement device is a one-way clutch, the engine rotational speed increases until the automatic transmission reaches the synchronous state), but the rise of the engine's output torque does not occur after synchronization, that is, after engagement. This causes a sudden rise in the output shaft torque, causing an increase in shift impact.

Japanese Patent Application Laid-open No. 5a-20, 7,556 and Patent Application No. 58-4
No. 00 discloses that the amount of advance of the ignition timing is changed during the shift period to reduce the output torque of the engine, thereby suppressing the shift impact. discloses or suggests nothing.

Purpose An object of the present invention is to provide an internal combustion engine control device for an automatic transmission vehicle that is capable of suppressing a shift impact after the substantial engagement of a low-speed frictional engagement device is completed during a downshift. It is.

Structure In order to achieve this object, the internal combustion engine control device for an automatic transmission vehicle of the present invention includes an output torque increase/decrease means for an internal combustion engine;
The automatic transmission includes a high-speed friction engagement device that achieves a high-speed gear, and a low-speed friction engagement device that achieves a low gear that is one step lower than the high-speed gear. At the time of downshifting from the gear friction engagement device to the low gear friction engagement device, the output torque of the internal combustion engine is reduced after the low gear friction engagement device substantially ends the sliding engagement.

Function and Effect After the substantial engagement of the low-speed friction engagement device is completed, the internal combustion t?
3. As a result of reducing the output torque of the engine, the rise of the output torque of the engine is suppressed, and the sudden rise of the output shaft torque of the automatic transmission after the end of engagement accompanying the rise is also alleviated.

In this way, it is possible to suppress the shift impact of the low-speed frictional engagement device in the case of downshifting.

Preferably, the low-speed frictional engagement device is a one-way clutch, the output torque increasing/decreasing means of the internal combustion engine is an advance angle control means for controlling the amount of advance of the ignition timing, and the advance angle control means is a one-way clutch. The advance angle control means reduces the amount of advance of the ignition timing within a predetermined time after the synchronization time of the directional clutch.
In the first period, the amount of advance angle is decreased by a slope α, and in the second period following the first amount of paddy, the amount of advance angle is kept constant,
In the third period following the second period, it is increased toward the original value at a slope β.

Since the rise of the output torque of the engine after synchronization differs depending on the driving conditions of the vehicle, the length of the first to third periods,
Preferably, the slopes α and β are functions of the vehicle speed or the intake throttle opening.

Preferably, the synchronization time detection means for detecting the synchronization time of the one-way clutch includes means for detecting a reference time, a timer for measuring elapsed time from the reference time, and detecting the time when the elapsed time reaches a predetermined value as the synchronization time. It has a means for determining that.

The reference time is the time when the piston of the accumulator of the high-speed gear friction engagement device, which is released by downshifting as the amount of accumulator depression increases, or the time when the piston of the accumulator of the high-speed gear friction engagement device reaches the oil discharge position. This can be the time at which the electric signal for the control solenoid valve of the shift valve that is switched from the high speed position to the low speed position is changed.

Example The present invention will be explained with reference to the embodiments shown in the drawings.

In FIG. 1, a fluid torque converter 14, an overdrive device 16, and an adder drive device 18 are coaxially provided between an input shaft 10 and an output shaft 12 of an automatic transmission. The lock-up clutch L/C is provided in parallel with the fluid torque converter 14, and under predetermined operating conditions, the engine power is transmitted to the overdrive device 1 via the lock-up clutch L/C without passing through the fluid torque converter 14.
6. The overdrive device 16 has one planetary gear device 20, and the adder drive device 1118 has two planetary gear devices 20.
It has two planetary gears 22 and 24. The connection between the rotating elements of the planetary gear system N20, 22.24 and the fixing of the rotating elements are the clutches CO to C2 and the brakes 80 to B3.
, and one-way clutches FO to F3.

FIG. 2 shows the relationship between the gear stage and the engagement state of each frictional engagement device. O indicates the engaged state, △ indicates the engaged state only when the engine is driven, D is the drive range, 3 is the third range, 2 is the second range, shi is the low range, R is the reverse range, 0/D respectively mean overdrive.

Returning to FIG. 1, the hydraulic control circuit 30 includes a plurality of electromagnetic valves 32.
These electromagnetic valves 32 are used for friction engagement devices other than one-way clutches (including lock-up clutches L/C).

) is controlled. The ECT (electronically controlled transmission) computer 36 calculates the gear position and gear timing from the vehicle speed ■ and the intake throttle opening O, etc.
The solenoid valve 32 is controlled based on the calculated value.

An EFI (m-control fuel injection) computer 38 calculates the fuel injection rate and ignition timing from the engine rotational speed Ne, intake air flow rate Q, etc., and controls the engine 40.

Koshicomputer 38 high-speed acquisition friction engagement device for EFI (
When downshifting from 4th gear to 3rd gear, brake BO1 When downshifting from 3rd gear to 2nd gear, brake C2 When downshifting from 2nd gear to 1st gear, brake An input signal can also be received from the switch 42 that detects when the piston of the accumulator in B2) is in the oil discharge position.

FIG. 3 shows a control mode when a downshift from third speed to second speed is performed during power-on. With this downshift, clutch C2 is switched from an engaged state to a released state, and one-way clutch Fl is switched from a released state to an engaged state.

At time tl, a switching command from the third speed to the second speed is generated, and the control signal for the 2-3 shift electric aerosol valve 32 is switched.

In this way, the 2-3 shift valve of the hydraulic control circuit 30 is
The clutch C2 is switched from the high speed position to the second speed position, and the servo oil pressure Pc2 of the clutch C2 begins to decrease.

At time t2, the piston of the accumulator of clutch C2 begins to move from the oil storage position to the oil discharge position, and the decrease in servo oil pressure Pc2 becomes gradual.

At time t3, the piston of the accumulator of clutch C2 reaches the oil discharge position, and thereafter the servo oil pressure rapidly decreases.

At time t4, the rotating members of the one-way latch F1 are synchronized, that is, the one-way clutch F1 is in an engaged state. During the period from time t3 to time t4, the one-way latch F] is still in an idle state, so the engine rotational speed Ne increases and the output shaft torque of the automatic transmission decreases.

After time t4, the one-way clutch F1 is engaged, so the output shaft torque of the automatic transmission increases.

After time t4, from time t4 to time t5 is the first
The period TI from time t5 to time t6 is defined as a second period T2, and from time t6 to time t7 is defined as a third period T3. Before time t4 and after time t7, the ignition timing advance amount rt is controlled to the original value ■[0. The original value 1tO is defined based on the engine load and the engine rotational speed, and is usually the advance angle amount at which the magnitude of knocking is within an allowable value and the engine output torque is maximum.

Within the first period PJJTI, the advance angle amount rt is decreased from ItO at a slope α. Within the second period T2, the advance angle It
is held at a value lower than the original value ■tO by a predetermined value Ia. Within the third period T3, the advance angle It has a slope β of ItO
be raised towards.

As a result of the decrease in the advance angle amount It from time t4 to time t7, the rise in the output torque of the engine is suppressed, and thereby the rise in the output shaft torque of the automatic transmission is also suppressed, and the shift @
J-connection is relaxed. If such advance angle reduction control is not performed, the output shaft torque of the automatic transmission will be at time t4.
Induced by the subsequent sudden rise in engine output torque, the third
As shown by the broken line in the figure, it rises rapidly and fluctuates greatly.

In order to detect time t4, the base time is detected, and the time when the elapsed time from the reference time reaches TO is set as time t4. & As for residence time, solenoid valve 3 is activated for downshift.
The time tl at which the control signal No. 2 switches, or the time t3 detected by the switch 42 and at which the piston of the accumulator of the clutch C2 reaches the oil discharge position is used. Note that even if the time at which the predetermined time TO has elapsed from the reference time is not exactly t4, and therefore the time at which the advance angle amount rt is reduced is slightly shifted before or after time t4, the impulse S is suppressed.
=, there is no effect at all.

FIG. 4 is a flowchart of a routine for decreasing the amount of advance of the ignition timing.

First, it is determined whether the reference time is, for example, time t3 or apricot in FIG. 3 (step 50), and if it is the reference time, a timer is set (step 52), and the elapsed time T from the reference time is measured. Elapsed time T and To, TO + TI, To +
Compare TI +T2 and TO+TI +T2+T3 (steps 54.58, 62.66), TO≦T
< In case of TO+TI, rto-α・t (however, t
is the elapsed time from time t4), TO+TI≦T<
In the case of To + TI -1-T2, ItO-Ia,
TO±TI + 72≦T < To + TI+T2
+ In the case of T3, ItO−Ia+β・t (however, t
is the elapsed time from time t6), and the advance angle fiIt is
(Steps 56, 60, and 64).

FIG. 5 is a functional block diagram of the present invention. The synchronization time detection means 70 detects the actual engagement end time of the friction engagement device engaged by the downshift 1 during power-on (if this friction engagement device is a one-way clutch, the actual engagement end time). = synchronized time) is detected. A reference time is detected based on the detection signal of the switch 42 or the shift signal from the ECT computer 36, and the time when the elapsed time measured by the timer 72 reaches a predetermined value TO is determined as the actual engagement end time (synchronization time). ). Advance angle amount control means 474 as an output torque increase/decrease means of the engine controls the first to third M interval T in relation to the elapsed time measured by the timer 72.
At I-T3, the advance angle It is decreased as shown in FIG. The ignition coil 76 is controlled to turn on and off the primary current by the advance amount control means 74, and when the primary current changes from on to off, a spark is generated in the ignition plug 78 and the mixture in the combustion chamber is ignited. .

In the embodiment, the low-speed friction engagement device is a one-way clutch that does not require hydraulic opening and opening, but the present invention can also be applied to a case where the low-speed friction engagement device is a hydraulic type that requires hydraulic control. will be obvious to those skilled in the art.

In the embodiment, the effective engagement end time of the low-speed friction engagement device is detected based on the elapsed time from the reference time, but it can be detected based on the output shaft torque of the automatic transmission and the rotational speed of the engine. Alternatively, it may be directly detected from the turbine rotational speed of the fluid torque converter and the rotational speed of the output shaft of the automatic transmission.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the entire internal combustion engine control device for an automatic transmission vehicle, FIG. 2 is a diagram showing the relationship between gears and the engaged state of each frictional engagement device, and FIG. 3 is according to the present invention. Diagram 4 showing changes in the amount of advance of ignition timing in the internal combustion engine control device, etc.
FIG. 5 is a flowchart of a routine for decreasing the amount of advance of ignition timing. FIG. 5 is a functional block diagram of the present invention. 36... ECT computer, 42... switch, 70... synchronous time detection means, 72... timer 74
...Advance angle control means. Figure 1 Figure 3 - Invention □ Time t

Claims (1)

[Scope of Claims] 1. An output torque increase/decrease means for an internal combustion engine, a high speed friction engagement device for achieving a high speed, and a low speed friction for achieving a low speed that is one step lower than the high speed. The automatic transmission includes an engagement device, and when downshifting from a high speed friction engagement device to a low speed friction engagement device, after substantial engagement of the low speed friction engagement device is completed, An internal combustion engine control device for an automatic transmission vehicle, characterized in that the output torque of the internal combustion engine is reduced. 2. The low-speed friction engagement device is a one-way clutch, and the output torque increasing/decreasing means of the internal combustion engine is an advance amount control means that controls the amount of advance of the ignition timing, and the advance amount control means is a one-way clutch. 2. The internal combustion engine control device according to claim 1, wherein the amount of advance of ignition timing is decreased within a predetermined time after the synchronization time. 3. The advance angle amount control means decreases the advance angle amount at a slope α in the first period, maintains the advance amount constant in the second period following the first period, and decreases the advance angle amount at a slope α in the second period following the first period. 3. The internal combustion engine control device according to claim 2, wherein the internal combustion engine control device increases the internal combustion engine control device toward the original value at a slope β during the period 3. 4. The internal combustion engine control device according to claim 3, wherein the lengths of the first to third periods and the slopes α and β are functions of vehicle speed or intake throttle opening. 5. The synchronization time detection means for detecting the synchronization time of the one-way clutch includes means for detecting a reference time, a timer for measuring the elapsed time from the reference time, and determining the time when the elapsed time reaches a predetermined value as the synchronization time. The internal combustion engine control device according to claim 2, characterized in that it has the following means. 6. A patent claim characterized in that the reference time is the time when the piston of the accumulator of the high-speed gear friction engagement device, which is released by downshifting as the amount of depression of the accumulator increases, reaches the oil discharge position. The internal combustion engine control device according to item 5. 7. The reference time is characterized in that the reference time is the time at which the electrical signal of the control solenoid valve of the shift valve is switched from the high gear position to the low gear position due to a downshift associated with an increase in the amount of depression of the accumulator. An internal combustion engine control device according to claim 5.