JPH0422740B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle.

BACKGROUND OF THE INVENTION Controlling engine output torque during gear shifting in order to alleviate gear shifting impact is well known, for example, as disclosed in Japanese Patent Application Laid-open No. 77138/1983. In that case, depending on the driving condition of the vehicle, if the engine output torque is already sufficiently small, such as when the throttle opening is low, controlling the engine output torque may actually worsen the gear shifting operation. Therefore, the control range of engine output torque is limited to a specific driving state of the vehicle.

Problems to be Solved by the Invention However, if the operating state of the vehicle is in the engine output torque control region at the start of the shift, but changes to the non-control region before the end of the shift operation, or vice versa. In such cases, despite such changes, if execution or cancellation of engine output torque control is determined based on the operating state at the start of the shift and is not changed, a large shift impact may occur.
On the other hand, the shift time becomes longer, which may cause damage to the friction material of the friction engagement device.

An object of the present invention is to provide an automatic gear shift capable of achieving good engine output torque reduction control when the driving state of a vehicle changes between an engine output torque reduction control area and a non-control area during gear shifting operation. The purpose of this invention is to provide a control device for the machine.

Means for Solving the Problems In order to achieve this object, the automatic transmission control device of the present invention is configured such that a predetermined parameter that quantitatively represents the degree of engine output torque related to the driving state of the vehicle is detecting means for detecting whether the engine output torque is in a control region or a non-control region in which the engine output torque should be reduced; engine output torque control means for executing or canceling output torque reduction control;
and The detection operation of the detection means is continued during the gear shifting operation, and when the predetermined parameter changes between a control region related to engine output torque reduction control and a non-control region, the engine output by the engine output torque control means is determined. It has a switching means for switching execution or cancellation of torque reduction control.

Effects and Effects of the Invention As a result of adopting such a configuration, the automatic transmission control device of the present invention provides a predetermined control system that quantitatively represents the degree of engine output torque related to the driving state of the vehicle at the time of starting a shift. Even if control is once executed to reduce the engine output torque during shift control based on the parameters, if the value of this parameter changes during the shift operation and moves out of the torque reduction control area,
Engine output torque reduction control is canceled. Conversely, even if the parameter is in the non-control region where engine output torque reduction control is not performed at the start of gear shifting, if the parameter value changes midway through and enters the control region, the engine output torque will be reduced. Control is switched to reduce the As a result, even though the engine output torque is in the engine output torque reduction control region during gear shifting, the engine output torque reduction control is not carried out, resulting in an excessive gear shifting time, which reduces the durability of the friction material of the friction engagement device. is avoided. Further, even though the engine output torque reduction control is in the non-control region during the gear shifting operation, the engine output torque reduction control is executed, and an increase in gear shift impact is avoided.

As a parameter that quantitatively represents the degree of engine output torque, for example, intake throttle opening can be used.

Further, it is advantageous that the engine output torque control means performs engine output torque reduction control by controlling the amount of advance of the ignition timing, the amount of fuel supply, the amount of intake air, the opening/closing timing of the intake and exhaust valves, or the boost pressure. be.

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

In FIG. 2, a fluid torque converter 14, an overdrive device 16, and an underdrive device 18 are coaxially provided between an input shaft 10 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, engine power is passed through the lock-up clutch L/C to the overdrive device 1 without passing through the fluid torque converter 14.
6. The overdrive device 16 has one planetary gear device 20, and the underdrive device 18 has two planetary gear devices 22, 24. The connection between the rotating elements of the planetary gear units 20, 22, 24 and the fixing of the rotating elements are provided by clutches C0 to C.
2, brakes B0 to B3 and one-way clutches F0 to F2.

FIG. 3 shows the relationship between the gear stage and the engagement state of each frictional engagement device. 〇 and × indicate the engaged state and released state, respectively, △ indicates that the engaged state is only when the engine is driven, D is the drive range, 2 is the second range, L is the low range, and R
stands for reverse range, and OD stands for overdrive.

Returning to FIG. 2, the hydraulic control circuit 30 has a plurality of solenoid valves 32, and these solenoid valves 32 operate the friction engagement devices (including the lock-up clutch L/C) excluding the one-way clutch. Engagement and release are controlled. Computer 36 for ECT (electronically controlled transmission)
calculates the gear position and shift timing from the vehicle speed V, intake throttle opening θ, etc., and controls the solenoid valve 32 based on the calculated values.

EFI (electronic fuel injection) computer 38
calculates the fuel injection amount and ignition timing from the engine rotational speed Ne, intake air flow rate Q, etc.
Controls 0.

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

FIG. 5 shows changes in the values of each parameter when the operating state of the vehicle changes from a non-control region to a control region of engine output torque during a gear shift operation. In this example, a case where the intake throttle opening degree θ is a predetermined value θ ₁ is defined as a non-control region of engine output torque, and a case where θ>θ ₁ is defined as a control region. On and off of the lock-up clutch mean the engaged state and the released state of the lock-up clutch, respectively, and a change in the gear shift output means that the control signal of the solenoid valve 32 has been switched and a gear shift operation has started.

Case A will be explained first.

At time _t1 , the change in gear determined based on the driving state of the vehicle is determined by the ECT computer 36.
judged by.

At time _{t2 ,} when a predetermined time T1 has elapsed from time _t1 , a shift command is generated based on the shift determination at time _t1 , and the control signal for the control valve 32 of the hydraulic control circuit 30 is switched.

After time _t2 , the time change in the engine rotational speed Ne is monitored. Although Ne changes greatly in the inertia phase, it remains almost constant before and after the inertia phase.

In this case, it is assumed that the intake throttle opening degree θ changes from a predetermined value θ ₁ or less to a value larger than θ ₁ at time t ₃ . Note that time t ₃ is a time before the inertia phase.

At time _t4 , the start of the inertia phase is detected, and in conjunction with this, the lock-up clutch L/C is turned from on to off. Lockup clutch L/
By turning off C, the fluid torque converter 14 absorbs fluctuations in the output shaft torque of the automatic transmission due to gear shifting. Furthermore, since the operating state of the vehicle is in the engine output torque control region at time t4, the engine output torque is decreased. Engine output torque is changed by controlling the amount of advance in ignition timing, the amount of fuel supplied from the fuel injection valve, the amount of intake air, the opening/closing timing of the intake and exhaust valves, or the boost pressure, which reduces the engine output torque. As a result, fluctuations in the output shaft torque of the automatic transmission are suppressed.

At time _t5 , the inertia phase ends, and along with this, the engine output torque is returned to its original value. This return is performed slowly over time _T2 , and undershoot or overshoot of the output shaft torque of the automatic transmission immediately after the inertia phase ends is suppressed.

At time _t6 , when a predetermined time _T3 has elapsed from time _t2 , the lock-up clutch L/C is turned back on from off.

Case B will be explained. In case B, it is determined that the operating state of the vehicle changes from the non-control region of the engine output torque to the control region at time _t7 after the start of the inertia phase. Since time t4 is in the non-control region, the reduction in engine output torque is suspended,
The engine output torque starts to decrease from time _t7 .
The return of engine output torque is the same as in case A.

FIG. 6 shows changes in each parameter when the operating state of the vehicle changes from the engine output torque control region to the non-control region during the gear shifting operation. time t ₄
Since this is in the control region, the engine output torque starts to decrease. When the operating state of the vehicle changes from the control region to the non-control region at time _t8 , a command to restore the engine output torque is immediately issued, and the engine output torque quickly returns to its original value.

Figures 7 and 8 show the upshift speed change control performed when the lock-up clutch L/C is on (engaged) when the torque transmitted from the engine to the drive wheels is positive (power on). This is a routine flowchart. The variable T is a flag used to detect the stage of control of the lock-up clutch L/C, and the variable I is a flag used to detect the stage of control of the engine output torque.
The variable S is a flag used to detect that the engine is in a period related to execution or termination of engine output torque control.

First, the process proceeds to each step depending on the values of variables T and I (steps 46 and 48).

When both T and I are 0, that is, before the shift control starts, the corresponding gear is determined based on the intake throttle opening θ, the vehicle speed V, the shift prohibition signal, etc., and the shift is performed. It is determined whether or not there is a need for shifting (step 50), and only if there is a need for shifting, the process proceeds to the next step 52.

Next, the elapsed time Ta since it was determined that there is a need for gear shifting is compared with a predetermined value _T1 (step 5).
2), if Ta<T ₁ , assign 1 to the variable T (step 54); if TaT ₁ , assign 0 to T (step 56), issue a speed change command (step 58), and The control signal for the valve 32 is switched.

After that, the change in engine speed Ne is monitored, and Ne
and a predetermined value Ne ₁ (step 60). The predetermined value Ne ₁ is set corresponding to the product No.Il of the automatic transmission output rotational speed No. and the automatic transmission gear ratio Il before upshifting, and when the inertia phase starts, Ne decreases. Becomes NeNe ₁ . Ne＞Ne ₁
In this case, assign 1 to variable I (step 62),
When NeNe becomes ₁ , 1 is assigned to the variable S (step 64), and the process proceeds to step 66.

The intake throttle opening degree θ is compared with a predetermined value θ ₁ (step 66), that is, it is determined whether the operating state of the vehicle is in the engine output torque control region or in the non-control region. only turns off the lock-up clutch L/C (step 6).
8).

If it is within the control range, the lock-up clutch L/C is turned off and the engine output torque is reduced (step 70). Furthermore, the time change of the engine rotational speed Ne is monitored, and Ne is compared with a predetermined value _Ne2 (step 72). The predetermined value Ne2 is set corresponding to the product No.Ih of the output shaft rotation speed No of the automatic transmission and the gear ratio Ih of the automatic transmission after upshifting, and when the inertia phase approaches the end, Ne<Ne It becomes ₂ . If Ne＞Ne ₂ , the variable I
2 is substituted into (step 74), and when NeNe reaches ₂ , the engine output torque is restored (step 76), and then 0 is substituted into variable S (step 78).

Time elapsed since the shift command in step 58 was issued
Tb is compared with a predetermined value _T3 (step 80), and Tb
In the case of _T3 , 2 is assigned to the variable T (step 82), but when the predetermined value _T3 has elapsed, the lock-up clutch L/C is allowed to turn on (step 84), and the variables T and I are set to 0. (step 86). If the vehicle operating state after shifting is in the engagement range of the lock-up clutch L/C, step 84
By executing the lock-up clutch L/C, the lock-up clutch L/C becomes engaged.

The value of S is determined (step 88), and only when S=1, that is, when the period is related to execution or cancellation of engine output torque control, the process proceeds to step 90. The time change of the intake throttle opening θ is monitored (step 90), the intake throttle opening θ is compared with a predetermined value _θ1 (step 92), and it is determined whether engine output torque control is being executed (step 94). Alternatively, it is determined whether engine output torque control is not being executed (step 96). If the engine output torque control is being executed at θθ ₁ , that is, if the vehicle operating state switches from the engine output torque control area to the non-control area while the engine output torque control is being executed, step 7
Proceed to step 6 and cancel engine output torque control. θ＞
If the engine output torque control is not being executed at θ ₁ , that is, if the driving state of the vehicle is switched from the engine output torque non-control area to the control area while the engine output torque control is not being executed, the process proceeds to step 70. Start engine output torque control. In other cases, ie, if the operating state of the vehicle does not change between the engine output torque control region and non-control region, the reset is performed.

FIG. 1 is a functional block diagram of the present invention. The throttle opening sensor 100 is the intake throttle opening θ
Detect. The vehicle operating state detection means 102 detects whether the vehicle operating state is in the engine output torque reduction control region or in the non-control region based on, for example, the intake throttle opening θ. When the shift command is sent from the shift command generation means 106, the output torque control means 104 executes or cancels the output torque control of the engine 40 based on the control region and non-control region of engine output torque reduction. The switching means 108 monitors the output of the vehicle driving state detection means even after the transmission command is generated, and when the vehicle driving state changes between the engine output torque reduction control region and the non-control region, the switching means 108 changes the output of the engine output torque control means 104. Switches execution or cancellation of engine output torque reduction control.

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 can be implemented with various modifications and variations.

[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 device, Fig. 3 is a chart showing the operating state of each friction engagement device at each gear stage, and Fig. 4 is a diagram showing the operating state of each friction engagement device in each gear stage. Diagram illustrating a shift diagram, No. 5
Figure 6 shows changes in each parameter when the vehicle driving state changes from a non-control area to a control area.
Figure 7 shows changes in each parameter when the vehicle driving state changes from a controlled region to a non-controlled region.
This figure is a flowchart of the speed change control routine, and FIG. 8 is a flowchart of the engine output torque control change routine. 40... Engine, 102... Vehicle operating state detection means, 104... Engine output torque control means, 10
8...Switching means.

Claims (1)

[Claims] 1. A predetermined parameter that quantitatively represents the degree of engine output torque related to the driving state of the vehicle is defined as a control region and a non-control region in which the engine output torque should be reduced when performing a gear shift operation. Detection means for detecting which of the following is present; Engine output torque control means for executing or canceling engine output torque reduction control during shift operation in relation to the detection result by the detection means at the time of starting the shift;
and The detection operation of the detection means is continued during the gear shifting operation, and when the predetermined parameter changes between a control region related to engine output torque reduction control and a non-control region, the engine output by the engine output torque control means is determined. A control device for an automatic transmission, comprising: switching means for switching execution or cancellation of torque reduction control.