JPH0735228A - Speed change control device for automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To provide a speed change control device for an automatic transmission for a vehicle without generating quick increase of driving force exceeding a value desired by a driver. CONSTITUTION:When pre-speed change driving force Fb is determined by a pre-speed change driving force determining means 92, and determination of speed change is detected by a speed change determination detection means 90, a post-speed change driving force Fa after speed change by the determination of the speed change is achieved by a post-speed change driving force determining means 94. In the where a change width between the pre-speed change driving force Fb and the post-speed change driving force Fa (=¦Fa-Fb¦) exceeds a preliminarily set determination reference value alpha1, the detected speed change determination is changed into speed change into a gear stage on the driving force restricting side. Quick increase of the driving force to a vehicle exceeding a value desired by a driver can be liminted, thereby favorable driving performance can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle having a plurality of forward gears, an engine load amount such as an accelerator pedal operation amount and a throttle valve opening amount and a vehicle speed can be calculated from a preset shift map. There is a shift control device of the type that determines the gear stage to shift based on. According to such a shift control device, there is an advantage that the automatic transmission can be automatically switched to the gear stage suitable for the running state of the vehicle. For example,
This is the shift control device for an automatic transmission for a vehicle, which is described in JP-A-4-25665.

[0003]

By the way, in the above-described conventional shift control device for an automatic transmission for a vehicle, when the driver depresses the accelerator pedal to a large extent, the shift diagram indicates the accelerator pedal operation amount. Thus, the speed reduction gear is determined and the speed is automatically downshifted to the speed reduction gear. However, in particular, in the case where a large operation of the accelerator pedal is performed, which is called kickdown, so that the throttle valve is fully opened, in addition to the fact that the engine output changes from a relatively small state to the maximum output, ,
Since the automatic transmission shifts down to the reduction gear, the driving force of the vehicle suddenly increases beyond the driver's desired value.
There is a possibility that good drivability may not be obtained. In particular,
Such inconvenience becomes more remarkable as the engine output of the vehicle increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shift control device for an automatic transmission for a vehicle, which does not cause a sudden increase in driving force exceeding a driver's desired value. To provide.

[0005]

SUMMARY OF THE INVENTION An object of the present invention to achieve such an object is to provide an automatic transmission for a vehicle having a plurality of forward gears from an engine load amount set according to a preset shift diagram. And a speed change control device that executes a speed change determination based on a vehicle speed and supplies a speed change output for obtaining a gear position determined by the speed change determination to the automatic transmission, wherein: A gear shift judgment detecting means for detecting, (b) a gear shift precursor power determining means for determining a gear shift precursor power which is an actual driving force of the vehicle before the gear shift, and (c)
A post-shift driving force determining means for determining a post-shift driving force after the shift is achieved by the shift determination when the shift determination is detected by the shift determination detecting means; and (d) the shift precursor power and the post-shift driving. When the change width or the change rate of the force exceeds a preset judgment reference value, the shift judgment changing means for changing the shift judgment detected by the shift judgment detecting means is included.

[0006]

According to this structure, the shift pre-driving power determining means determines the shift pre-driving power which is the actual driving force of the vehicle before the shift, and when the shift change determination detecting means detects the shift change, the post-shift drive force is generated. The determining means determines the post-shift driving force after the shift is achieved by the shift determination. When the change width or change rate of the shift pre-driving power and the post-shift drive force exceeds the preset judgment reference value by the shift judgment changing means, the shift judgment detected by the shift judgment detecting means is It is changed so that the gear is shifted to the gear that suppresses the force.

[0007]

Therefore, according to the present invention, when the change width or change rate of the shift pre-driving power and the post-shift driving force exceeds the preset judgment reference value, the shift judgment is changed. During a downshift of the transmission, the gear shifts to a gear that suppresses the driving force rather than the original gear, so that the driving force of the vehicle may suddenly increase beyond the driver's desired value. Limited and good drivability is obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a skeleton view showing an automatic transmission for a vehicle, the shift of which is controlled by a shift control device according to an embodiment of the present invention. In the figure, the output of the engine 10 is input to the automatic transmission 14 via the torque converter 12 and transmitted to the drive wheels via a differential gear unit and an axle (not shown).

The torque converter 12 is the engine 1
0 pump impeller 18 connected to crankshaft 16
A turbine runner 22 connected to the input shaft 20 of the automatic transmission 14, a lock-up clutch 24 that directly connects the pump impeller 18 and the turbine runner 22, and a one-way clutch 26 prevent rotation in one direction. And a stator 28 that is installed.

The automatic transmission 14 is provided with a first transmission 30 for switching between high and low gears, and a second transmission 32 for switching between reverse gear and four forward gears. The first transmission 30 includes an HL planetary gear device 34 including a sun gear So, a ring gear Ro, and a planetary gear Po rotatably supported by the carrier Ko and meshed with the sun gear So and the ring gear Ro, a sun gear So and a carrier. It includes a clutch Co and a one-way clutch Fo provided between Ko and a brake Bo provided between the sun gear So and the housing 41.

The second transmission 32 is a first planetary gear unit 36 comprising a sun gear S1, a ring gear R1, and a planet gear P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
, Sun gear S2, ring gear R2, and carrier K
2 and a second planetary gear unit 38, which is rotatably supported by the sun gear S2 and a ring gear R2 and is meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3, which are rotatably supported by the sun gear S2. S3 and a third planetary gear set 40 including a planet gear P3 meshed with the ring gear R3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2 and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. The ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and the sun gear S1 and the sun gear S are provided.
A clutch C2 is provided between the shaft 2 and the intermediate shaft 44. In addition, a band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2 is provided on the housing 41.
It is provided in. A one-way clutch F1 is provided between the sun gear S1 and the sun gear S2 and the housing 41.
And the brake B2 are provided in series. The one-way clutch F1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to rotate in the opposite direction to the input shaft 20.

A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 41. This one-way clutch F
2 is configured to be engaged when the ring gear R3 tries to rotate in the reverse direction. The clutch Co, C
1, C2, brake Bo, B1, B2, B3, B4,
It is a hydraulic friction engagement device in which a friction material is engaged when hydraulic pressure is applied.

In the automatic transmission 14 configured as described above, for example, according to the operation table shown in FIG. 2, the reverse first gear and the forward five gears are switched. In FIG. 2, the ∘ mark indicates the operating state, and the X mark indicates the non-operating state.

As shown in FIG. 3, in the intake pipe of the engine 10 of the vehicle, a first throttle valve 52 and a throttle actuator 54 operated by an accelerator pedal 50.
And a second throttle valve 56 operated by. Further, an engine rotation speed sensor 58 for detecting the rotation speed of the engine 10, an intake air amount sensor 60 for detecting the intake air amount of the engine 10, an intake air temperature sensor 62 for detecting the intake air temperature, the first throttle valve 5 described above.
The throttle sensor 64 for detecting the opening degree θth of 2 and the vehicle speed sensor 6 for detecting the vehicle speed V from the rotational speed of the output shaft 42 and the like.
6, a cooling water temperature sensor 68 for detecting the cooling water temperature of the engine 10, a brake switch 7 for detecting the operation of the brake
0, an operation position sensor 74 for detecting the operation position of the shift lever 72, etc. are provided.
Engine speed N _E , intake air amount Q, intake air temperature T
Signals representing Ha, the opening degree θth of the first throttle valve θ, the vehicle speed V, the engine cooling water temperature THw, the brake operating state BK, and the operation position Psh of the shift lever 72 are sent to the electronic control unit for engine 76 and the electronic control unit for shifting 78. It is being supplied. Further, a signal indicating the turbine rotation speed N _T is supplied from the turbine rotation speed sensor 75 that detects the rotation speed of the turbine runner 22 to the electronic shift control device 78. Further, a signal indicating the kick down operation is supplied from the kick down switch 77 that detects that the accelerator pedal (not shown) is operated to the maximum operation position to the electronic shift control device 78.

The electronic control unit for engine 76 includes a CPU,
A so-called microcomputer having a RAM, a ROM, and an input / output interface, the CPU processes an input signal according to a program stored in the ROM in advance while utilizing a temporary storage function of the RAM, and executes various engine controls. For example, the fuel injection valve 80 is controlled to control the fuel injection amount, the igniter 82 is controlled to control the ignition timing, the bypass valve (not shown) is controlled to control the idle speed, and the throttle actuator is controlled to control the traction. The second throttle valve 56 is controlled by 54.

The electronic shift control device 78 is also a microcomputer similar to that described above, and the CPU uses the temporary storage function of the RAM while processing the input signal in accordance with the program stored in the ROM in advance, and the hydraulic control circuit 84. Each solenoid valve or linear solenoid valve is driven. For example,
The electronic shift control device 78 uses a linear solenoid valve SLT to generate an output pressure P _SLT having a magnitude corresponding to the opening degree θth of the first throttle valve 52, and a linear solenoid valve SLN to control the accumulator back pressure. To drive the linear solenoid valve SLU in order to control the slip amount of the lockup clutch 24. Further, the electronic shift control device 78 determines the gear position of the automatic transmission 14 and the engagement state of the lock-up clutch 24 based on the actual throttle valve opening θth and the vehicle speed V from the previously stored shift diagram. The solenoid valves S1, S2, S3 are driven so that the determined gear and engagement state are obtained, and the solenoid valve S4 is driven when engine braking is generated. The lock-up clutch 24 is released in the first speed gear stage and the second speed gear stage of the automatic transmission 14, but in the third speed gear stage and the fourth speed gear stage, the throttle valve opening θth and the vehicle speed Vth.
Based on the above, the release, slip, or engagement region is determined, and if it is the slip region, the lockup clutch 2
4 is slipped, and if it is an engagement area, it is engaged. This slip control is for suppressing the rotational loss of the torque converter 12 as much as possible while absorbing the rotational fluctuation of the engine 10.

FIG. 4 shows the control of the electronic shift control device 78.
It is a functional block diagram explaining the principal part of a control function. In the figure
In addition, the vehicle before shifting by the shift pre-driving power determining means 92
Gear shift precursor power F which is the actual driving force of_bIs determined and
When a speed change determination means 90 detects a speed change determination,
After the shift, the driving force determination means 94 determines the shift.
Post-shift driving force F after the shift is achieved_aIs determined.
Then, the shift determination change means 96 causes the shift precursor power F
_bAnd driving force F after shifting_aChange range (= | F_a-F _b|)
Preset reference value α₁If more than
The gear change judgment detected by the gear change judgment detecting means 90 is
Changed to shift to the shift gear that suppresses power.
Be done.

The main part of the operation of the electronic shift control device 78 will be described below with reference to the flow chart shown in FIG.

In step SR1 of FIG. 5, well-known input signal processing is performed, and the throttle valve opening θth corresponding to the load amount of the engine 10, the vehicle speed V, the operation position Psh of the shift lever 72, the automatic transmission 14 are processed. After the input signal such as the current gear position of the vehicle is read, in step SR2, the current driving force of the vehicle, that is, the shift pre-driving power F _b is calculated based on the actual throttle valve opening θth and the vehicle speed V from the relationship stored in advance. Is calculated. For example, based on the actual vehicle speed V, a relationship corresponding to the vehicle speed V is selected from the relationships shown in FIG. 6 stored in advance for each vehicle speed, and the actual throttle valve opening θth and the automatic Transmission 1
The gear shift precursor power F _b is obtained based on the current gear stage of No. 4. The current gear stage of the automatic transmission 14 is determined and read based on the shift output output from the electronic shift control device 78 to the automatic transmission 14, for example.

At the subsequent step SR3, whether or not the downshift shift determination is made based on the actual throttle valve opening θth and the vehicle speed V from the downshift shift diagram shown in FIG. 7 in the shift control. To be judged. If the determination in step SR3 is negative,
This routine is ended.

However, if the determination in step SR3 is affirmative, then in the subsequent step SR4, the post-shift driving force F _a when the gear stage to be achieved according to the downshift shift determination is actually achieved. It is calculated prior to the gear shift. The post-shift driving force F _a is calculated in the same manner as step SR2 by using the gear stage to be achieved in place of the current gear stage. In step SR5, after the transmission driving force F _a and the gear precursor power F _b
It is determined whether or not the change width (= | F _a −F _b |) between and is larger than the preset determination reference value α ₁ . This judgment reference value α ₁ is for judging whether or not the driving force change width is such that a sudden increase of the driving force exceeding the driver's desired value occurs due to the execution of the downshift, and an experiment is conducted in advance. This is the value that was calculated.

If the determination in step SR5 is negative, the amount of increase in the driving force due to the execution of the downshift is small, and the shift determination is changed to prevent the driving force from exceeding the driver's desired value. Since no control is required, this routine is ended. However, if the determination in step SR5 is affirmative, the shift output changing process is executed in step SR6. That is, for example, when the vehicle running state is changed from the point M to the point N in the shift diagram of FIG. 7 by depressing the accelerator pedal, the shift determination from the fifth gear to the second gear is performed in the above step. When detected in SR3, step S
At R6, the shift determination is changed from the fifth gear to the third gear. Then, in step SR7,
A shift command is output from the shift electronic control unit 78 based on the changed shift determination, and the automatic transmission 14 achieves the third speed gear.

As described above, according to this embodiment, before shifting
It is changed by step SR2 corresponding to the driving force determining means 92.
Fast precursor power F_bIs determined, and the shift determination detection means 90
If the shift determination is detected in step SR3
Step SR corresponding to the post-shift driving force determining means 94
4 changes after the shift is achieved by the shift determination.
Quick after-drive force F_aIs determined. And the shift judgment change hand
By the step SR6 corresponding to the step 96, the shift precursor power
F_bAnd driving force F after shifting_aChange range (= | F_a-F _b｜)
Is a preset judgment reference value α₁If the value exceeds
The gear shift judgment detected by step SR3 suppresses the driving force.
It is changed to shift to the gear on the controlling side.

As described above, the shift precursor power F_bAnd after shifting
Driving force F_aChange range (= | F_a-F _b|) Is preset
Judgment reference value α₁If it exceeds the
Therefore, when downshifting the automatic transmission 14,
Is a gear that suppresses the driving force rather than the original gear position.
As it shifts to the gear, it changes from point M to point C in FIG.
The driving force for the gear shift to is only increased. Therefore, the driver
It is restricted that the driving force of the vehicle suddenly increases beyond the desired value of
Therefore, good drivability can be obtained. Also kick
Immediately after the down operation to reduce the driving force of the vehicle.
Return the accelerator pedal to and shift up to the third gear.
There is no need for extra operations such as making it.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 8 shows another step SR5-1 used in place of the step SR5 of the embodiment shown in FIG. In the figure, in step SR5-1, if the rate of change (= F _a / F _b ) between the shift pre-driving power F _b and the post-shift driving force F _a exceeds the preset judgment reference value β ₁ , the following step In SR6, the shift determination is changed so that the shift is performed to the gear that suppresses the driving force. This judgment reference value β _{1 is} also for judging whether or not the driving force change rate is such that the driving force rapidly increases beyond the desired value of the driver due to the execution of the downshift. This is the value that was calculated. Also in this embodiment, the same effect as that of the above-mentioned embodiment can be obtained.

In the flowchart shown in FIG. 9, after the input signal processing is performed in step SS1, the current engine load amount, for example, the accelerator operation amount Accb is a signal from the throttle sensor 64 or an accelerator operation amount sensor (not shown) in step SS2. It is detected based on. Next, in step SS3, it is determined in the shift control whether or not the downshift shift determination is made based on the actual throttle valve opening θth and the vehicle speed V from the downshift shift diagram shown in FIG. 10, for example. It If the determination in step SS3 is negative,
This routine is ended.

However, if the determination in the above step SS3 is affirmative, in step SS4, the accelerator pedal operation amount Acca after the shift at that time, that is, the accelerator pedal that causes the shift determination of the downshift is depressed. The accelerator pedal operation amount Acca after being released is detected. Then, in step SS5, the accelerator operation amount Accb before the shift and the accelerator pedal operation amount Acca after the shift are performed.
It is judged whether or not the change width (= | Accb-Acca |) between and is larger than a predetermined judgment reference value α ₂ . This judgment reference value α ₂ is for judging whether or not the driving force change width is such that a sudden increase in the driving force exceeding the driver's desired value occurs due to the execution of the downshift. This is the value that was calculated.

If the determination in step SS5 is negative, the amount of increase in the driving force due to the execution of the downshift is small, and the shift determination is changed to prevent the driving force from exceeding the driver's desired value. Since no control is required, this routine is ended. However, if the determination in step SS5 is affirmative, the shift diagram changing process is executed in step SS6. That is, for example, in FIG.
In the gear shift diagram of Fig. 3, a part of the first gear shift line, the second gear shift line, and the third gear shift line shown by solid lines are changed as shown by broken lines, and based on the changed gear shift diagram, The shift determination is performed again. For example, in FIG. 10, when there is a change from the M ₁ point to the N ₁ point by depressing the accelerator pedal, in step SS3, the fourth gear is changed to the first gear.
Although the shift determination to the high speed gear stage is performed, the above step SS
In 6, the shift determination is changed from the fourth gear to the second gear. Similarly, changes to shift determination from shift determination from fifth gear due to the change from M ₂ points to the N ₂ points to the second gear is fifth gear to third gear stage, M ₃
The shift determination from the fifth speed gear stage to the third speed gear stage is changed to the shift determination from the fifth speed gear stage to the fourth speed gear stage due to the change from point _{3 to} point N ₃ .

Then, in step SS7, a shift command is output from the shift electronic control unit 78 based on the changed shift determination changed in step SS6, and the automatic transmission 14 attains the third speed gear. It Here, since the accelerator operation amount Acc corresponding to the engine load corresponds to the output torque of the engine 10, it can be used as the driving force of the vehicle for convenience.

[0033] Therefore, according to this embodiment, the shift precursor powered by step SS2 corresponding to the determining means 92 corresponding to the shift precursor power F _b pre-shift accelerator operation amount Accb is determined, corresponding to the shift decision detecting means 90 Step SS3
When the shift determination is detected by, in step SS4 corresponding to the post-shift driving force determining means 94, the post-shift accelerator pedal operation amount Acca corresponding to the post-shift driving force F _a after the shift has been achieved is determined . Then, in step SS6 corresponding to the shift determination changing means 96, the accelerator operation amount Accb before the shift and the accelerator pedal operation amount Acc after the shift are Acc.
When the range of change from a (= | Accb-Acca |) exceeds a preset determination reference value α ₂ , the shift determination detected in step SS3 is applied to the gear stage on the side that suppresses the driving force. It will be changed to shift. As a result, the same effect as that of the above-described embodiment can be obtained.

FIG. 11 shows step SS5 of the embodiment of FIG.
And SS6, an example is shown in which step SS5-1 for determining the kickdown operation of the accelerator pedal based on the signal from the kickdown switch 77 is inserted.
In the present embodiment, in addition to the case where the determination in step SS5 is affirmative, the shift determination is changed when it is determined that the kick down operation of the accelerator pedal is performed.
The present embodiment is characterized in that the shift determination change process is performed for a relatively large change in driving force.

FIG. 12 shows step SS5-2 used in place of step SS5 of FIG. In this step SS5-2, the rate of change between the accelerator operation amount Accb before the shift and the accelerator pedal operation amount Acca after the shift (= | Acc
b-Acca | / Δt) is a preset judgment reference value β ₂
It is determined whether or not the value exceeds, and if it exceeds, the step SS6 and subsequent steps are executed. This judgment reference value β _{2 is} also for judging whether or not the driving force change rate is such that the driving force suddenly increases beyond the driver's desired value due to the execution of the downshift. This is the value that was calculated. Also in this embodiment, the same effect as that of the above-mentioned embodiment can be obtained.

FIG. 13 shows step SS5- of FIG.
2 and step SS5-1 of FIG. 11 are shown in place of step SS5 of FIG. Also in this embodiment, the same effect as that of the above-mentioned embodiment can be obtained.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other aspects.

For example, the throttle valve opening θth is a variable corresponding to the engine load, and is the accelerator pedal operation amount Acc.
Therefore, the throttle valve opening degree θth may be used instead of the accelerator pedal operation amount Acc in the embodiment of FIGS. 9 to 13. Further, instead of these variables, other variables representing the engine load such as the fuel injection amount and the intake pipe negative pressure may be used.

Further, in the embodiment of FIG. 8 described above, the change rate of the shift pre-driving power F _b and the post-shift driving force F _a is (F _a / F
_{Although b} ) was used, (| F _a −F _b | / Δt) may be used.

After steps SS5 and SS5-1 of FIG. 11, step SS5-2 of FIG. 12 may be executed.

Further, although the automatic transmission 14 having the five forward gear stages has been described in the above-mentioned embodiment, the automatic transmission 14 having the four or six or more forward gear stages is also applicable. It doesn't matter.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of an automatic transmission for a vehicle in which a gear stage is controlled by a shift control device according to an embodiment of the present invention.

FIG. 2 is a table showing a relationship between a combination of operations of a plurality of friction engagement devices and gear stages established by the combination in the automatic transmission of FIG.

FIG. 3 is a block diagram illustrating a hydraulic control circuit and an electric control circuit that form the control device for the automatic transmission of FIG.

FIG. 4 is a functional block diagram illustrating a main part of a control function of the electronic shift control device of FIG.

5 is a flowchart for explaining a main part of control operation of the electronic shift control device of FIG.

FIG. 6 is a diagram showing a pre-stored relationship used for calculating the driving force in FIG.

FIG. 7 is a diagram showing a shift diagram used for shift determination in FIG. 5;

FIG. 8 is a diagram showing a main part of operation in another embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 5 in another embodiment of the present invention.

FIG. 10 is a diagram showing a shift diagram used for shift determination and change of shift determination in the embodiment of FIG. 9;

FIG. 11 is a diagram illustrating an essential part of the operation of another embodiment of the present invention.

FIG. 12 is a diagram illustrating an essential part of the operation of another embodiment of the present invention.

FIG. 13 is a diagram illustrating an essential part of the operation of another embodiment of the present invention.

[Explanation of symbols]

 14: Automatic transmission 90: Gear shift determination detection means 92: Gear shift precursor power determination means 94: Post-shift drive force determination means 96: Gear shift determination change means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Hojo, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor, Masato Kaigawa 1, Toyota Town, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Masahiko Ando, 10 Takane, Fujii-cho, Anjo City, Aichi Prefecture, Aisin AW Co., Ltd. (72) Inventor, Mamoru Niimi, 10 Takane, Fujii-cho, Aki City, Aichi Prefecture Within

Claims (1)

[Claims] 1. In a vehicle automatic transmission having a plurality of forward gears, a gear shift determination is executed based on an engine load amount and a vehicle speed from a preset gear shift diagram, and the gear shift determined by the gear shift determination. A shift control device for supplying a shift output to the automatic transmission to obtain a shift determination detection means for detecting the shift determination, and a shift pre-driving power which is an actual driving force of a vehicle before shifting. A shift pre-driving force determining unit for determining the shift pre-driving force, and a shift-after driving force determining unit for determining a shift-after driving force after the shift is achieved by the shift determination when the shift determination is detected by the shift determination detecting unit; When the change width or the change rate of the shift pre-driving power and the post-shift drive force exceeds a preset judgment reference value, a shift judgment changing means for changing the shift judgment detected by the shift judgment detecting means is provided. A shift control device for an automatic transmission for a vehicle, comprising: