JPH09310627A - Torque reduction control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an amount of torque to be reduced certainly without deteriorating operability while securing responsiveness in torque reduction controlling for reducing shift shock. SOLUTION: When torque-reduction is required at the time of transmission, a target opening of a throttle valve is controlled and the opening of the throttle valve which is opened and closed by a motor shows the corrected target value (S1 to S4). Within a specified time from correction of the target value (S5), a torque reduction request signal is output to an engine control module(ECM), and retarding controlling of an ignition timing is executed simultaneously (S6). After specified time has passed, the retarding controlling of the ignition timing is cancelled, and the torque is reduced only by controlling the opening of the throttle valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque down control device for an automatic transmission, and more particularly to a technique for forcibly reducing the output torque of an engine during gear shifting in order to reduce gear shift shock.

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, a torque down control for forcibly reducing the output torque of the engine by retarding the ignition timing or fuel cut during gear shifting has been performed in order to reduce gear shift shock and improve drivability. It is known (see Japanese Patent Laid-Open No. 3-81539, etc.).

[0003]

However, when the output torque is reduced by retarding the ignition timing, the exhaust temperature is increased by the retard control, and therefore, the retard amount is required to realize the required torque reduction. In some cases, the gear shift shock cannot be reduced sufficiently.

When the output torque is reduced by cutting the fuel, the required torque reduction can be realized, but if the fuel cut state is long, the liquid fuel (wall flow) adhered to the inner wall of the intake port. Therefore, when the fuel supply is restarted, the supplied fuel is used to restore the wall flow rate,
There was a risk of problems such as making the air-fuel ratio lean.

As a method of reducing the output torque of the engine, there is a method of reducing the intake air amount of the engine in addition to the retard of the ignition timing and fuel cut, and for example, the throttle valve opening is controlled by an actuator such as a motor. When the system is provided, by forcibly reducing the opening of the throttle valve, it is possible to satisfy a relatively large torque reduction request, and in this method, fuel cut is performed. Since it does not exist, it is possible to suppress the occurrence of air-fuel ratio fluctuations.

However, for example, when the throttle valve opening is controlled by an actuator such as a motor, the throttle valve opening reaches the target opening even if the control is started with the generation of the torque down request signal. Therefore, there is a problem that the output torque of the engine cannot be lowered with good response to the generation of the torque down request signal.

The present invention has been made in view of the above problems, and it is required that the output torque of the engine can be lowered with good response to the torque down request at the time of shifting and the drivability is not deteriorated. An object of the present invention is to provide a torque down control device for an automatic transmission that can achieve torque down.

[0008]

Therefore, the invention according to claim 1 is a torque down control device for an automatic transmission for forcibly reducing the output torque of the engine in order to reduce a shift shock when shifting the automatic transmission. At the time of a torque down request at the time of gear shifting of the automatic transmission, the control for forcibly reducing the output torque by the intake air amount control is performed, and during the response delay period of the intake air amount control,
It is characterized in that control for forcibly reducing the output torque is performed by at least one of ignition timing control and fuel supply amount control.

That is, even if the output torque of the engine is forcibly reduced by controlling the intake air amount, the output torque cannot be immediately reduced due to the response delay. Therefore, in the period in which the output torque cannot be sufficiently reduced due to the response delay,
The output torque is reduced by controlling the ignition timing and / or the fuel supply amount with good responsiveness.
Then, when the response of the intake air amount control catches up,
The ignition control and / or the fuel control are stopped so that the required torque reduction can be obtained only by controlling the intake air amount. Therefore, it is possible to avoid the influence on the drivability due to the ignition control and / or the fuel control (the rise of exhaust temperature, the fluctuation of the air-fuel ratio).

In addition to the so-called fuel cut, the control of the fuel supply amount includes a control for reducing the fuel amount with respect to the air amount so that the air-fuel ratio is leaner than usual. Also,
By retarding the ignition timing, the engine output torque can be reduced, and by reducing the intake air amount, the engine output torque can be reduced even when the air-fuel ratio is constant.

On the other hand, the invention according to claim 2 is a torque down control device for an automatic transmission for forcibly reducing the output torque of an engine to reduce a shift shock when shifting the automatic transmission. It is configured as shown in. FIG.
In the above, the torque down request means generates a torque down request signal when the automatic transmission shifts.

The first torque control means is means for forcibly reducing the output torque of the engine by at least one of the ignition timing control and the fuel supply amount control, and the second torque control means is the engine by the intake air amount control. Is a means for forcibly reducing the output torque of. Here, the torque control switching means starts the torque control by the first torque control means and the second torque control means, respectively, when the torque down request signal is generated, and controls the intake air amount by the second torque control means. After the period corresponding to the response delay elapses, the torque control by the first torque control means is stopped, and the torque control by only the second torque control means is performed.

In such a configuration, the control by the first torque control means and the control by the second torque control means are started in parallel with the generation of the torque down request signal. Since the two-torque control means generally has poorer responsiveness, the output torque can be reduced only by the first torque control means in the initial stage. When the response of the second torque control means catches up, the control by the first torque control means is stopped and the output torque is reduced only by the second torque control means, that is, the intake air amount control.

According to the third aspect of the present invention, the second torque control means forcibly reduces the opening degree of the valve that changes the opening area of the intake system of the engine by the actuator, thereby reducing the intake air amount of the engine. The output torque is reduced to reduce the output torque. When the valve installed in the intake system is configured to open / close an actuator such as a motor, the opening area of the valve is forcibly reduced to reduce the opening area, thereby reducing the intake air amount of the engine. Forcibly reduce,
Therefore, the output torque of the engine is reduced.

According to a fourth aspect of the invention, the valve for controlling the opening of the second torque control means is a throttle valve. As a valve that controls the opening area of the intake system, an auxiliary air amount control valve (a so-called idle control valve) that bypasses the throttle valve and adjusts the amount of auxiliary air supplied to the engine
However, it is better to control the opening of the throttle valve.
A large amount of torque reduction can be secured, which is more preferable.

According to a fifth aspect of the present invention, the second torque control means forcibly changes the opening / closing characteristics of the intake valve to reduce the intake air amount of the engine and reduce the output torque. . For example, it is possible to forcibly change the filling efficiency by changing the overlap by changing the opening / closing timing of the intake valve to reduce the intake air amount, and it is also possible to reduce the intake air amount by reducing the lift amount. Is.

According to the sixth aspect of the invention, the period corresponding to the response delay in the torque control switching means is set to a period from the start of the intake air amount control to the elapse of a preset time. That is, when a predetermined time elapses from the start of the intake air amount control by the second torque control means, the response of the intake air amount control, specifically, the change of the opening degree of the valve, the change of the opening / closing characteristic of the intake valve, etc. catch up. It is estimated that the desired torque reduction will be obtained,
The ignition control and / or the fuel control by the torque control means is stopped after the lapse of the predetermined time.

In the invention according to claim 7, the period corresponding to the response delay in the torque control switching means is a period from the start of the intake air amount control until the engine is operated by a preset number of cycles. It was configured. That is, it is estimated that when the engine is operated for a predetermined number of cycles from the start of the intake air amount control by the second torque control means, the response of the intake air amount control catches up and the desired intake air amount is obtained. The ignition control by the first torque control means and / or the fuel is stopped after being operated for the predetermined number of cycles.

According to the eighth aspect of the present invention, the period corresponding to the response delay in the torque control switching means is set to the period until the opening of the valve reaches the target opening. That is, the ignition control and / or the fuel control by the first torque control means is stopped when the opening of the valve that changes the opening area of the intake system reaches the target opening.

[0020]

According to the invention of claim 1 or 2, the response delay of the intake air amount control is compensated by the ignition timing control and / or the fuel supply amount control, and the output of the engine is well responded to the torque down request. There is an effect that the torque can be reduced, and after the response catches up, the torque reduction necessary for reducing the shift shock can be reliably obtained by the intake air amount control without deteriorating the drivability.

According to the third aspect of the present invention, the intake air amount is reduced by forcibly reducing the opening degree of the valve provided in the intake system of the engine, thereby reducing the output torque of the engine. There is an effect that the shift shock can be reduced. According to the invention described in claim 4, there is an effect that it is possible to surely meet a large torque reduction request by reducing the opening degree of the throttle valve to reduce the intake air amount.

According to the fifth aspect of the present invention, the intake air amount is reduced by forcibly changing the opening / closing characteristics of the intake valve, thereby reducing the output torque of the engine,
There is an effect that the shift shock can be reduced. According to the invention described in claim 6, it is possible to appropriately stop the ignition timing control and / or the fuel supply amount control, assuming that the control response of the intake air amount catches up when a predetermined time has elapsed from the start of the control. effective.

According to the seventh aspect of the invention, the control response of the intake air amount catches up after a predetermined number of cycles from the start of the control, and the ignition timing control and / or the fuel supply amount control can be appropriately stopped. effective. According to the invention of claim 8, in a configuration in which the opening degree of the valve interposed in the intake system is reduced to control the intake air amount, the ignition timing is reached when the opening degree of the valve reaches the target opening degree. There is an effect that the control and / or the fuel supply amount control can be surely stopped.

[0024]

Embodiments of the present invention will be described below. FIG. 2 is a system diagram showing a power system of a vehicle in the embodiment, in which the output of the engine 1 is transmitted to drive wheels (not shown) via a torque converter type automatic stepped transmission 2. ing.

A throttle valve 4 which is opened and closed by a motor 3 is interposed in the intake passage of the engine 1. The intake air amount of the engine 1 is adjusted by the opening of the throttle valve 4. The motor 3 is operated by a control signal from a throttle control module (hereinafter, referred to as TCM) 5.

A throttle valve opening signal from a throttle sensor 6 and a target throttle valve opening signal from an automatic transmission control unit (hereinafter referred to as A / T-C / U) 7 are input to the TCM 5 and the throttle valve is opened. The motor 3 is feedback-controlled so that the actual throttle valve opening detected by the sensor 6 matches the target throttle valve opening.

On the other hand, the A / T-C / U 7 has a vehicle speed signal from a vehicle speed sensor 8 and an accelerator opening signal from an accelerator opening sensor (not shown) for detecting the depression amount of an accelerator pedal operated by a driver. , Engine speed N
An engine speed signal from a rotation sensor 9 for detecting e (rpm) and a throttle valve opening signal from the throttle sensor 6 are input.

Then, the A / T-C / U 7 refers to a preset shift schedule based on the accelerator opening signal and the vehicle speed signal, and sends a shift signal to the automatic step-variable transmission 2. It is output and the automatic shift according to the shift schedule is performed. Also, the A / T-C / U
7 determines the target throttle valve opening signal, for example, as follows, and outputs it to the TCM 5.

First, the target driving force is set based on the accelerator opening and the vehicle speed, and then the target turbine torque is set based on the target driving force and the gear stage of the transmission 2. Then, the target throttle opening degree is determined based on the target turbine torque and the turbine speed, and is output to the TCM 5. However, the method for determining the target throttle valve opening is not limited to the above.

Furthermore, the A / T-C / U 7 generates a torque down request signal (torque down requesting means) to reduce the shift shock by forcibly reducing the output torque of the engine 1 at the time of shifting. An engine that controls the torque down request signal to control the ignition timing of the spark plug in the engine 1 and the fuel injection amount (fuel supply amount) by the fuel injection valve.
Output to the control module (hereinafter referred to as ECM) 10.

The ECM 10 executes retard control of ignition timing based on the torque down request signal or control for forcibly stopping fuel injection by the fuel injection valve (hereinafter referred to as fuel cut control), and the engine 1 Output torque is reduced (first torque control means). Further, the A / T-C / U 7 performs control to forcibly set the target throttle valve opening to decrease in response to the generation of the torque down request signal, and decreases the output torque by decreasing the intake air amount of the engine 1. It is designed to be lowered (second torque control means).

Here, the torque down control at the time of shifting will be described in detail with reference to the flow charts of FIGS. The flowchart of FIG. 3 shows the processing contents in the A / T-C / U 7. In step 1 (denoted as S1 in the drawing; the same applies hereinafter), it is determined whether or not a torque down request signal at the time of shifting is generated.

The torque down request signal is the A / T
It is assumed that it is generated in the processing of another routine by C / U7, and for example, the torque down signal is generated at the time of gear shifting in the acceleration state. The torque down signal may be added with information for distinguishing the degree of request for torque down. When the generation state of the torque reduction request signal is determined in step 1, the process proceeds to step 2 and the torque reduction amount is calculated. The torque reduction amount is calculated based on the type of shift (for example, first speed → second speed, etc.), engine torque (represented by throttle valve opening, etc.), engine speed, and the like.

In the next step 3, the target opening degree of the throttle valve is determined according to the torque reduction amount in order to reduce the intake air amount of the engine and reduce the output torque of the engine by the torque reduction amount. Specifically, the correction coefficient K _TVO of the target opening is determined according to the torque reduction amount as shown in FIG. 6, and the current target throttle valve opening set according to the target driving force or the like is set. The correction is set by the correction coefficient K _TVO .

Then, in the next step 4, the target throttle valve opening corrected and set according to the torque reduction amount is output to the TCM 5. In step 5, it is determined whether or not a predetermined time or a predetermined number of cycles has elapsed since the target opening degree corrected according to the torque down request signal was output to the TCM.

If the predetermined time or the predetermined number of cycles has not elapsed, the process proceeds to step 6 to output the torque down request signal to the ECM 10,
Torque down control by ignition timing control and / or fuel cut control is executed. Therefore, at the initial stage of the torque down request signal, the ignition timing control and / or the fuel cut control are performed in parallel with the throttle control for forcibly reducing the intake air amount of the engine.

On the other hand, if it is determined in step 5 that the predetermined time or the predetermined number of cycles has elapsed since the torque down request signal was generated and the correction control of the throttle opening was started, step 7 Go to and ECM
The output of the torque down request signal to 10 is canceled, and the retard control and / or the fuel cut control of the ignition timing by the ECM 10 are stopped.

Therefore, when the torque down request signal is generated and the correction control of the throttle opening is started for a predetermined time or for a predetermined number of cycles, the engine output torque is forced only by the correction control of the throttle opening. The state is changed to a state in which it is intentionally lowered (torque control switching means). Even if the control for forcibly reducing the throttle valve opening is started based on the generation of the torque down request signal, it takes a relatively long time to change the throttle opening until the effect of such control is obtained. There is a long response delay period. On the other hand, since the ignition timing correction and the fuel cut control have relatively good response, the ignition timing correction is performed until the effect of the intake air amount reduction control by the throttle opening correction can be obtained (response delay period). The fuel cut control is performed to decrease the output torque with good response.

Further, the ignition timing correction and the fuel cut control are limitedly performed only in the initial stage of the torque down request signal generation, and the final required torque down amount is obtained by the correction of the throttle valve opening. Even if the required torque reduction amount is relatively large, it is possible to reliably meet such a requirement, and it is possible to suppress the occurrence of air-fuel ratio fluctuations after the torque reduction control.

That is, in the retard control of the ignition timing, the exhaust temperature rises due to the retard, so that the retard amount, in other words, the torque reduction amount is limited, and it becomes difficult to secure the necessary and sufficient torque reduction amount. However, when the throttle valve opening is reduced to reduce the intake air amount, a large torque reduction amount can be secured without significantly affecting the drivability. Further, if the fuel cut is performed for a long time, the air-fuel ratio fluctuation at the time of restarting the fuel injection will be caused. However, if the fuel cut is limited to the response delay period of the air amount control, the air-fuel ratio fluctuation occurs. Can be sufficiently suppressed.

The predetermined time is preferably set based on the time from the start of correction of the target opening of the throttle until the opening of the throttle valve actually reaches the corrected target. It is more preferable to change it according to the deviation between the actual opening and the corrected target opening. Therefore,
As shown in the flowchart of FIG. 8, step 5 of the flowchart of FIG. 3 may be changed to determination (step 5A) of whether or not the target opening and the actual opening match. With the configuration, it is possible to reliably stop the ignition control and the fuel control when the target opening is reached, and shift to the state of only the air amount control.

The predetermined number of cycles is preferably set based on the number of cycles required for the intake air amount to decrease by an amount corresponding to the required torque down amount from the start of correction of the target opening of the throttle. It is more preferable to change it according to the amount of down. Furthermore, in the above, the throttle valve opening is reduced in order to forcibly reduce the intake air amount of the engine and reduce the output torque. For example, the opening degree of an auxiliary air amount control valve (so-called idle control valve) that opens and closes the air passage may be corrected. However, in the configuration in which the opening of the auxiliary air amount control valve is corrected, if the controllable air amount is small and the required torque reduction amount is large, it may not be possible to meet such a request, and the above throttle valve It is preferable to correct the opening.

Now, how the ECM 10 is controlled based on the torque down request signal will be described with reference to the flow charts of FIGS. The flowchart of FIG.
A case where the ignition timing is retarded according to the torque down request signal is shown. When the input of the torque down request signal is determined in step 11, the process proceeds to step 12, and the torque down amount is calculated in the same manner as in step 2.

The torque reduction amount is the A / T-
A configuration using the calculation result in C / U7 may be used. In step 13, the retard amount of the ignition timing is determined according to the torque reduction amount (see FIG. 7). And step
At 14, the basic ignition timing according to the engine load, the number of revolutions, etc. is retarded by the retard amount, and the retard control is performed to reduce the output torque of the engine.

On the other hand, the flow chart of FIG. 5 shows the case where the fuel cut is performed in response to the torque down request signal.
When it is determined in step 21 that the torque down request signal is input, the process proceeds to step 22. For example, in the case of a 6-cylinder engine, a fuel cut for forcibly stopping the fuel injection for 3 cylinders of the 6 cylinder engines is executed, and the engine is cut by the fuel cut. The output torque of is forcibly reduced.

Here, only one of the ignition timing control shown in the flow chart of FIG. 4 and the fuel cut shown in the flow chart of FIG. 5 may be executed, or both of them may be executed simultaneously. Alternatively, the ignition timing control may be executed when the torque reduction request amount is small, and the fuel cut may be executed when the torque reduction request amount is large. The composition is good.

Further, in an engine capable of lean combustion (for example, a direct injection type gasoline engine), the output torque is reduced by forcibly making the air-fuel ratio lean according to the torque down signal instead of fuel cut. It is also possible. By the way, in the above, as a method of reducing the output torque by reducing the intake air amount of the engine, a method of reducing the opening area of the valve such as the throttle valve provided in the intake system to reduce the opening area is shown. In an engine equipped with a mechanism (hereinafter referred to as a variable valve mechanism) that changes the opening / closing characteristics (opening / closing timing and / or lift amount) of the intake valve, for example, the intake air amount can be changed by changing the overlap angle or the lift amount. It is possible to reduce the output torque of the engine by reducing (charging efficiency).

The flowchart of FIG. 9 shows the EC when the opening / closing characteristics of the intake valve are controlled by the ECM10.
The state of the torque down control in M10 is shown. First, in step 31, it is determined whether or not the torque-down request signal from the A / TC / U7 side is input. If there is a torque down request, the process proceeds to step 32, and the torque down amount is calculated in the same manner as above.

In the next step 33, the opening / closing characteristic of the intake valve for realizing the torque reduction amount is determined (second torque control means). For example, when the opening / closing timing of the intake valve can be changed, the intake air amount (charging efficiency) can be reduced by setting the overlap angle between the opening timing of the intake valve and the opening timing of the exhaust valve. When the lift amount can be changed, the intake air amount can be reduced by reducing the intake valve lift amount, and further, the intake air amount can be reduced by both the overlap angle and the lift amount. It is possible.

In step 34, a control signal is output to the variable valve mechanism so as to achieve the determined opening / closing characteristics. In step 35, a control signal is output to the variable valve mechanism, and it is determined whether or not a predetermined time has elapsed since the change of the opening / closing characteristics of the intake valve was started. The predetermined time is the time required to actually switch the opening / closing characteristics of the intake valve by the variable valve mechanism.If the predetermined time has not elapsed, the routine proceeds to step 36, where retard control of ignition timing and Fuel cut (or lean air-fuel ratio) control is performed (first torque control means).

When the predetermined time has elapsed, the routine proceeds to step 37, where the ignition timing retard control and fuel cut (or lean air-fuel ratio) control are stopped, and the air amount control is performed by changing the opening / closing characteristics of the intake valve. The output torque is reduced only by (torque control switching means). In the case of an engine that has a variable valve mechanism, but does not have a mechanism that electronically controls the opening of the throttle valve, the above control forcefully reduces the intake air amount of the engine when a torque down request is made, and the output torque is reduced. It is possible to reduce and reduce the occurrence of gear shift shock.

The intake air amount can be forcibly reduced by various intake control valves (such as a swirl control valve and a variable intake control valve for switching the length of the intake port). The controllable intake air amount is small, and the operating conditions are limited, which is not preferable. In addition, in a configuration in which the opening of the throttle valve is reduced to reduce the engine output, in addition to the first throttle valve that is linked to the accelerator, a second motor-driven second throttle valve for traction control is used as the first throttle valve. In an engine provided in series with, the opening degree of the second throttle valve may be controlled.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the invention described in claim 2;

FIG. 2 is a system diagram showing a power system of the vehicle in the embodiment.

FIG. 3 is a flowchart showing torque down control by correcting a target throttle opening.

FIG. 4 is a flowchart showing torque down control by retard control of ignition timing.

FIG. 5 is a flowchart showing torque down control by fuel cut.

FIG. 6 is a diagram showing a correlation between a correction coefficient of a target throttle opening and a torque reduction amount.

FIG. 7 is a diagram showing a correlation between a retard amount of ignition timing and a torque reduction amount.

FIG. 8 is a flowchart showing control for switching torque control based on a comparison between an actual opening and a target opening.

FIG. 9 is a flowchart showing torque down control in which the air amount is reduced by changing the opening / closing characteristics of the intake valve.

[Explanation of symbols]

 1 Engine 2 Automatic Stepped Transmission 3 Motor 4 Throttle Valve 5 TCM 6 Throttle Sensor 7 A / T-C / U 8 Vehicle Speed Sensor 9 Rotation Sensor 10 ECM

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location F02D 41/04 310 F02D 41/04 310G 330 330G 43/00 301 43/00 301K 301B 301H F02P 5 / 15 F16H 61/00 F16H 61/00 F02P 5/15 F // F16H 59:18

Claims (8)

[Claims] 1. A torque down control device for an automatic transmission for forcibly reducing an output torque of an engine in order to reduce a shift shock during a gear shift of the automatic transmission, which is a torque down request during a gear shift of the automatic transmission. At the same time, the control for forcibly reducing the output torque is performed by the intake air amount control, and the output torque is forcibly controlled by at least one of the ignition timing control and the fuel supply amount control during the response delay period of the intake air amount control. 1. A torque down control device for an automatic transmission, characterized in that the control is performed to reduce the torque. 2. A torque down control device for an automatic transmission for forcibly reducing the output torque of an engine to reduce a shift shock during a shift of the automatic transmission, the torque down request signal being applied during a shift of the automatic transmission. For reducing the engine output torque by at least one of the ignition timing control and the fuel supply amount control, and the engine output torque forcibly by the intake air amount control. Second torque control means for reducing the amount of the intake air, and when the torque down request signal is generated, the torque control by the first torque control means and the second torque control means is started, respectively, while the intake air amount by the second torque control means is started. After the period corresponding to the control response delay has elapsed, the torque control by the first torque control means is stopped and the second torque control means is stopped. A torque down control device for an automatic transmission, comprising: torque control switching means for shifting to torque control only by the torque control means. 3. The second torque control means forcibly reduces the opening of a valve that changes the opening area of the intake system of the engine by an actuator, thereby reducing the intake air amount of the engine and increasing the output torque. 3. The torque down control device for an automatic transmission according to claim 2, wherein the torque reduction control device reduces the torque. 4. The torque down control system for an automatic transmission according to claim 3, wherein the valve whose opening degree is controlled by the second torque control means is a throttle valve. 5. The second torque control means forcibly changes the opening / closing characteristics of the intake valve to decrease the intake air amount of the engine and decrease the output torque. Automatic transmission torque down control device. 6. The period corresponding to the response delay in the torque control switching means is a period from the start of the intake air amount control to the passage of a preset time. 2. A torque down control device for an automatic transmission according to any one of 1. 7. The period corresponding to the response delay in the torque control switching means is a period from the start of the intake air amount control until the engine is operated for a preset number of cycles. Item 6. A torque down control device for an automatic transmission according to any one of items 2 to 5. 8. The method according to claim 3, wherein the period corresponding to the response delay in the torque control switching means is a period until the opening of the valve reaches a target opening. Torque down control device for automatic transmission.