JPS61105228A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE:To allow an impact due to shifting in a transmission to be relaxed by reducing an engine output when the number of revolution of an engine exceeds the stated value within the stated time since the time when a shift operation has been effected from a stop range to a run range where the car speed is lower than the stated one. CONSTITUTION:When a shift operation is effected by a driver from a stop range (N range for example) to a run range (D range for example) while an accel pedal is abruptly stepped, the number of revolution of an engine is rapidly increased where the throttle is quickly opened. This condition is detected as a quick start time when the number of revolution Ne of the engine is found to exceed the stated value within the stated time by both a shift operation detecting device 66 and a quick start detecting device 68 after the shift to run has been effected. Here, the shift operation detecting device detects a shift operation by an output from a shift position sensor 60, and the quick start detecting device receives the output signal from a car speed sensor 62 and an engine speed sensor 64. Consequently, this condition allows an output reducing device 72 to be operated permitting an engine output torque to be reduced.

Description

[Detailed description of the invention] Industrial use sorting The present invention relates to a control device for a vehicle automatic transmission.

In vehicles equipped with an automatic transmission, the accelerator pedal must be pressed to switch to N (neutral) range or P (baking) range.
A large shift error may occur when the range is shifted from the stop range L) to the driving range such as the drive J range, or when the accelerator pedal is pressed immediately after such a range shift to suddenly start the vehicle. This is because frictional engagement devices for travel ranges such as forward clutches and reverse clutches have a buffer area for their servo oil pressure (for example, this buffer area corresponds to the area in which the piston of an accumulator moves, and the increase in servo oil pressure is When the servo oil pressure becomes very gradual), the engagement is not completed and the next servo oil pressure shifts to a rapidly increasing region, and as the force acting on the travel range friction engagement device rapidly increases in this servo oil pressure rapidly increasing region, the automatic transmission This is because the output hm increases sharply.In a two-wheel drive vehicle, such a shift impact can be alleviated to some extent by slipping of the drive wheels, but if the weakest part of the drive system is damaged by the impact load at this time. In addition, the amount of work and power of the friction engagement device for the travel range may become excessive, and there is a risk that the friction material may be photographed.Furthermore,
In a four-wheel drive vehicle, the driving force is dispersed and slippage of the driving wheels is less likely to occur, so in order to withstand impact loads, it is necessary to significantly increase the capacity of each component of the drive system. There are significant manufacturing cost, weight, and size disadvantages.

Japanese Patent Application No. 58-112665 discloses that when there is a shift operation from the stop range to the drive range, the engine rotational speed is appropriately lowered and then the engagement operation of the friction engagement device for the drive range is not started immediately. Although the engagement operation has started, the engagement of the friction engagement device for the travel range may be delayed, and the start may be delayed against the driver's intention.

Problems to be Solved by the Invention The purpose of the present invention is to moderate the shift impact and impact load when a shift operation is made from the stop range to the drive range without delaying the engagement of the friction engagement device for the drive range. An object of the present invention is to provide a control device for an automatic transmission capable of alleviating the above.

Means for Solving the Problems To achieve this object, the automatic transmission control device of the present invention includes: a shift operation detection means for detecting a shift operation from a stop range to a driving range; and a shift operation detection means for detecting vehicle speed. Vehicle speed detection means to detect engine rotation speed 8! If there is a shift operation from the stop range to the drive range during a period when the bundle speed is below a predetermined vehicle speed and the engine rotation speed becomes equal to or higher than the predetermined engine rotation speed within a predetermined time after the shift operation. and output torque reducing means for reducing the engine output torque in parallel with the transition of the travel range friction engagement device to the locking state.

Effects of the invention When a driver tries to start suddenly with a shift operation,
In other words, if there is a shift operation from the stop range to the drive range while the vehicle speed is below a predetermined vehicle speed, and the engine rotation speed becomes higher than the predetermined engine rotation speed within a predetermined time after the shift operation, the drive range friction coefficient Since the engine output torque is reduced in parallel with the transition of the friction engagement device to the engaged state, the torque applied to the friction engagement device for the travel range when it is engaged is maintained within the allowable value, and As a result, when the frictional engagement device is engaged, the shift impact and impact load can be alleviated.

In addition, unlike the prior art, there is no need to delay the engagement operation of the friction engagement device for the travel range in order to alleviate the shift impact and impact load during the shift operation, so it is possible to avoid delays in starting the vehicle. can.

Preferably, the output torque reducing means gradually changes the engine output torque when the engine output torque is restored. Thereby, it is possible to suppress fluctuations in the automatic transmission gear output shaft torque upon completion of engagement of the travel range friction engagement device, and to alleviate impact.

Preferably, the output torque control means controls the ignition timing advance amount, fuel supply amount, intake air flow rate, opening/closing timing of intake and exhaust valves, or supercharging pressure.

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

In FIG. 2, a fluid torque converter 14, an overdrive device 16, and an amplifier drive device 18 are coaxially provided between an input shaft IO and an output shaft 12 of the 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 transferred to the overdrive device via the lock-up clutch L/C without passing through the fluid torque converter 14.
16. The overdrive device 16 has one planetary gearing 20 and the amplifier drive device 18 has two planetary gearings 22,24. The connection between the rotating elements of the planetary gear units 20, 22, 24 and the fixing of the rotating elements are performed by clutches CO to C2, brakes BO to B3, and one-way clutches FO to F2 r,'=.

Number 37 shows the relationship between the gear stage and the engagement state of each jiI friction engagement device. ○ and × indicate the engaged state and released state, respectively, Δ indicates that the engaged state is only when the engine is driven, D is the drive range, 2 is the second range,
shi means low range, R means reverse range, and O/D means overdrive.

Returning to FIG. 2, the hydraulic control circuit 30 includes a plurality of solenoid valves 32.
These electromagnetic valves 32 are used for friction engagement devices other than one-way clutches (including lock-up clutches L/C).

The binding and release of 2 is controlled. However, in general, for the forward clutch, the hydraulic control circuit is configured such that engagement is started by shifting to the travel range regardless of the state of the solenoid valve 32. ECT
The (electronically controlled transmission) computer 36 calculates the gear position and the gear timing from the vehicle speed V, the intake throttle opening θ, etc., and controls the solenoid valve 32 based on the calculated values.

An EFT (electronically controlled fuel injection) computer 38 calculates the fuel injection amount and ignition timing from the engine rotational speed Ne, intake air flow rate Q, etc., and controls the engine 40.

FIG. 4 illustrates a shift diagram in the D range. Each shift line is determined from the intake throttle opening θ and the vehicle speed V, and 1, 2, 3, and 0/D are 1st, 2nd, and 3rd gear, respectively.
speed, 4th gear (overdrive or direct connection M taste,
The direction of the arrow indicates the shift direction.

Figure 5 shows the changes in each parameter when the driver suddenly starts when the driver shifts from the stop range (for example, N range) to the driving range (for example, D range). The control principle of the invention will be explained.

At time t1, a range shift is performed from N range to D range, and the accelerator pedal is suddenly depressed.

Therefore, the intake throttle opening degree θ increases rapidly from time tl. Also, the servo oil pressure P of the forward clutch C1
sc starts to rise. Note that at time tl, the vehicle is generally stopped, that is, the vehicle speed V is below the predetermined value vl. The ECT computer detects that the shift has been performed using a shift position sensor.

It is determined whether the engine rotational speed Ne becomes equal to or higher than a predetermined value Ne1 during a period in which a predetermined time T1 elapses from time t1, and if Ne≧Nel, a command to reduce the engine output torque is generated, and the engine output torque is reduced to the specified value. Decrease quantitatively. If the driver depresses the accelerator pedal greatly, Ne≧Nel
At the time of normal starting, Ne<Nel, and no engine output torque reduction command is issued. The reduction in engine output torque is caused by the amount of ignition timing advance and the amount of fuel injected from the fuel injection valve (@
(opening time) or by reducing the intake air flow rate.

At time t3, the movement of the piston of clutch C1 ends, and clutch C1 begins to engage. Furthermore, at time t3, the engine output torque has already decreased sufficiently.

The piston of the accumulator for clutch CI begins to move at time t4, and ends its movement at time t5. The servo oil pressure Psc gradually increases from time t4 to t5, and this period is defined as a buffer region.

At time t6, engagement of clutch C1 is completed. Since the engine output torque is maintained at a small value in the time range including time t4 to t6, the clutch Ct smoothly completes engagement, and fluctuations in the output shaft torque of the automatic transmission when engagement is completed are suppressed. be done. As a result, the transmission collision connection,
It is possible to alleviate the impact zero load.

Due to the presence of the fluid torque converter 14, despite the engagement of clutch CI at time t6, the engine rotational speed Ne continues to decrease until time t7, and from time t7 Ne begins to increase. At time t7, that is, when a change in the engine rotational speed Ne from a decrease to an increase is detected, an engine output torque return command is generated, and the engine output torque gradually returns to its original value over time T2. , the return ends at time t8. Such gradual return suppresses fluctuations in the automatic transmission output shaft torque. Also, the time T2 required for recovery is determined by the intake swirler opening θ and the vehicle speed V.
It is preferable to use a function such as the following, whereby the output shaft torque of the automatic transmission is restored at an optimum time that can suppress fluctuations in the output shaft torque.

FIG. 6 is a flowchart of an engine output torque control routine according to the control principle explained in connection with FIG. As an example of the shift operation from the stop range to the running range, the shift operation from the N range to the D range is selected as in the case of FIG.

gkl! At step 4214, the values of T and r, which are flags that control the flow of control, are checked (step 4214).
3), if both are 0, proceed to step 44, and T=1
If l=0, proceed to step 48; if l=0, proceed to step 54. It is determined whether or not there has been a shift operation from the N range to the 0 range (step 44), and only if the determination is positive, the process proceeds to the following steps.

Next, compare the vehicle speed V and the predetermined value Vl (step 46),
It is determined whether the elapsed time T is within a predetermined value T1 since the shift operation to the N range or the IIE+D range is performed (step 48), and if T≦11, the engine rotation speed Ne is determined.
and a predetermined value Nel (step 50). If ■≦v1 at the time of the shift operation and Ne≧Net within the predetermined time Tl from the time of the shift operation, that is, only at the time of sudden start, clear the flag T and step J)
, Lu proceed to the step below. If Ne<Ne+, 1 is assigned to flag T (step 52).

Generating an engine output torque reduction command (step 53),
Sl! The output torque is decreased, and the time differential value Ne of Ne is reduced.
has changed from negative to positive, that is, at time t in FIG.
It is determined whether the number has reached 7 (step 54). If the determination is negative, flag I is cleared (step 55); if the determination is positive, an engine output torque return command is generated (step 56), the fi output torque is shifted to its original value, and flag [ is cleared (step 58).

FIG. 1 is a block diagram of the R function of the present invention. The shift position sensor 60, vehicle speed sensor 62, and engine rotational speed sensor 64 detect the position of the shift lever and the vehicle speed v, respectively.
1 and the engine rotational speed Ne are detected. The shift operation detection means 66 includes a shift range such as N and P; 2. Detects a shift operation to a driving range such as L. The sudden start detection means 68 detects that the above-mentioned shift operation is performed during the period M when the vehicle speed V is below the predetermined value v1, and the predetermined time T has elapsed since the shift operation time.
It is detected that the engine rotational speed Ne becomes equal to or higher than a predetermined value N1 within l, that is, a sudden start is detected.

Note that the timer 70 measures the elapsed time T from the time when the above-mentioned shift operation was performed, and the sudden start detection means 68 determines whether or not the predetermined time Tl has elapsed from this time T.

When a sudden start is detected, the output torque reducing means 72 reduces the output torque of the engine 40 by reducing the ignition timing advance amount in parallel with the transition of the friction engagement device for the travel range to the fully engaged state. decrease.

Although the present invention has been described with reference to embodiments, it will be obvious to those skilled in the art that the present invention is not limited thereto, and that various modifications and variations can be made within the spirit of the claims.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram of the present invention, Fig. 2 is a schematic diagram of the entire control system, Fig. 3 is a chart showing the operating state of each friction engagement device at each gear stage, and Fig. 4 is a shift in the D range. Figure 5 is a diagram showing changes in each parameter during sudden start,
FIG. 6 is a flowchart of a control routine for engine output torque at the time of sudden start. 40... Engine, 62... Vehicle speed sensor, 64... Engine rotation speed sensor, 66... Shift operation detection means, 7
0...Timer, 72...Output torque reduction means. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. Shift operation detection means for detecting a shift operation from the stop range to the drive range, vehicle speed detection means for detecting vehicle speed, engine rotation speed detection means for detecting engine rotation speed, and vehicle speed. If there is a shift operation from the stop range to the drive range during a period when the vehicle speed is below a predetermined vehicle speed, and the engine rotation speed becomes equal to or higher than the predetermined engine rotation speed within a predetermined time after this shift operation, the friction engagement device for the drive range A control device for an automatic transmission, comprising: output torque reducing means for reducing engine output torque in parallel with transition to an engaged state. 2. The control device according to claim 1, wherein the output torque reducing means gradually changes the engine output torque when the engine output torque is restored. 3. The output torque control means controls the amount of advance of the ignition timing, the amount of fuel supply, the flow rate of intake air, the opening/closing timing of the intake and exhaust valves, or the boost pressure. The control device according to item 1 or item 2.