JP2867738B2 - Transmission control device for automatic transmission - Google Patents

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, and more particularly, to a shift control corresponding to a shift prohibition condition while a predetermined shift prohibition condition such as incomplete warm-up is satisfied. The present invention relates to a shift control device for an automatic transmission for a vehicle, which inhibits a shift to a gear, and satisfies a shift prohibition condition such as completion of warm-up and permits a shift to the gear.

[0002]

2. Description of the Related Art Conventionally, there has been known an automatic transmission for a vehicle configured to prohibit a shift to a specific gear corresponding to a shift prohibition condition while a predetermined shift prohibition condition is satisfied.

[0003] For example, shifting to an overdrive stage or the like is prohibited until warm-up is completed, and the engine speed is maintained at a high level to prevent deterioration in driving performance due to the engine still being at a low temperature. Some are intended to complete the warm-up quickly.

In view of the purpose of prohibiting shifting to a predetermined high gear as described above, to prevent deterioration of driving performance, when the vehicle speed exceeds a predetermined vehicle speed, the output of the engine is reduced. Because it is sufficiently large and does not cause any particular problem in driving performance, there is also a technology that releases this shift to the predetermined high speed stage in consideration of fuel consumption efficiency and suppression of the generation amount of harmful components in exhaust gas. It has been disclosed (JP-A-58-34).
257).

[0005] Whether or not the warm-up has been completed is generally determined by determining whether or not the engine temperature or the engine coolant temperature has reached a predetermined value or more.

Japanese Patent Application Laid-Open No. S61-228148 discloses a shift control method for an automatic transmission for a vehicle in which a main transmission and a sub-transmission are simultaneously or alternately shifted to achieve a multi-stage shift. A technique has been disclosed in which the number of shift stages achieved when the oil temperature is low is reduced. According to the technique disclosed in Japanese Patent Application Laid-Open No. Sho 61-228148, when the oil temperature is low, the rising of the hydraulic pressure tends to be shifted as compared with the normal temperature, but the shift in which the shift shock is likely to be large is prohibited. The driving feeling can be improved.

[0007]

However, in the above-mentioned prior art, the following problems may occur.

That is, in the above-described conventional technology, the current traveling state is a state in which the gear should be the high speed gear, and the shift to the high gear is prohibited because the warm-up is not completed. Is satisfied, the warm-up is completed and the gear is shifted to the high speed stage.

For this reason, for example, the accelerator opening is constant,
Even when the vehicle is in a so-called steady running state, the shift to the high gear is executed suddenly (independent of the driver's accelerator operation or a change in vehicle speed) together with the detection of the completion of the warm-up, and the shift shock is generated. Will happen.

Generally, a shift occurs when the running state of a vehicle crosses a shift point on a shift diagram.
This is executed when one or both of the vehicle speed and the accelerator opening change (unsteady state).

[0011] Therefore, the shift shock is also masked during this unsteady state, so that the driver does not feel much discomfort. However, when the above-described conventional technology is executed, even when both the accelerator opening and the vehicle speed are constant and the vehicle is traveling in an extremely stable state, the detection of the warm-up completion and the high speed A shift to a stage is performed.

Therefore, the shift is executed when the driver does not expect the shift, and is felt as a large shift shock.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and it is intended to shift to a gear position in which gear shifting is prohibited when a predetermined gear shifting prohibition condition such as completion of warm-up is not satisfied. And a shift control device for an automatic transmission for a vehicle, wherein the shift is prevented when the vehicle is in a stable running state so that a shift shock not expected by a driver is prevented from occurring. .

[0014]

SUMMARY OF THE INVENTION The present invention relates to FIGS.
As shown in the gist, while a predetermined shift prohibition condition is satisfied, shifting to a specific shift speed corresponding to the shift prohibition condition is prohibited, and the shift prohibition condition becomes unsatisfied and the shift to the specific shift speed is prohibited. In a shift control apparatus for an automatic transmission that permits a shift, a shift request state determining unit that determines whether a current traveling state is a shift request state that should be the specific shift stage, and the predetermined shift inhibition condition is satisfied. A shift prohibition condition determining means for judging unsatisfaction, and when the predetermined shift prohibition condition is not satisfied under the shift request state, the shift is once released from the shift request state, and until the shift request state is reached again.
The above-mentioned problem has been solved by providing a shift prohibiting unit that prohibits the shift to the specific gear position.

The flow chart shown in FIG. 2 is based on an example of the present invention, in which the processing is executed for each timer interrupt at each time interval without any problem in processing.

[0016]

According to the present invention, for example, when the accelerator opening and the vehicle speed are constant and the vehicle is traveling in an extremely stable state, the shift of the automatic transmission occurs at an unexpected timing of the driver. This is made by paying attention to giving an uncomfortable shift shock to the driver.

That is, while the predetermined shift prohibition condition is satisfied, the shift to the specific shift speed corresponding to the shift prohibition condition is prohibited, and the shift prohibition condition is not satisfied and the shift to the specific shift speed is permitted. This is intended to reduce unpleasant shift shock when the predetermined shift prohibition condition is changed from being satisfied to not being satisfied.

The above-mentioned JP-A-58-34257 and JP-A-61-61257
In general, shift prohibition conditions such as -228148 are set for various purposes. However, the predetermined shift prohibition conditions targeted by the present invention include a warm-up state of the engine (detected by measuring the temperature of the engine cooling water and the temperature of the engine body),
Conditions resulting from the oil temperature of the hydraulic control device of the automatic transmission (independent of the driver's intention) correspond.

The predetermined shift prohibition conditions of the present invention also include conditions resulting from abnormality detection of detectors such as proximity sensors and temperature sensors, and control devices such as hydraulic solenoid valves. For example, when an abnormality occurs in such a detector or a control device, there is a method in which a shift to a gear position affected by the abnormality is prohibited to ensure a certain level of vehicle travel. In other cases, the present invention can be applied to a case where the shift prohibition is released upon recovery from an abnormality.

In the present invention, even if the predetermined shift prohibition condition is not satisfied while the predetermined shift prohibition condition is satisfied under a shift request state in which the current traveling state is to be a specific gear corresponding to the predetermined shift prohibition condition. In this case, the shift to the corresponding gear is not immediately performed.

That is, when the predetermined shift prohibition condition is not satisfied in such a shift request state, once the gear shift request state is deviated, and until the shift request state is established again, the shift to the specific gear position is not performed. The shift ban is continued.

Accordingly, the shift due to the fact that such a predetermined shift prohibition condition is not satisfied during the shift is performed when the driver again enters the shift request state where the occurrence of a shift can be predicted.

As a result, it is possible to prevent an uncomfortable shift shock caused by a shift executed when the driver does not expect.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 3 shows the gist of the first embodiment of the present invention, and FIG.
1 shows an overall outline of a more specific vehicle automatic transmission to which the first embodiment of the present invention is applied.

This automatic transmission has a torque converter 20 as a transmission section, an overdrive section 40, an underdrive section 6 having three forward stages and one reverse stage.
0.

The torque converter 20 includes a pump 2
1, a turbine 22, a stator 23, and a lock-up clutch 24.

The pump 21 is connected to the crankshaft 1 of the engine 1.
0, and the turbine 22 is connected to the overdrive section 40.
Are connected to the carrier 41 of the planetary gear set.

In the overdrive section 40,
A planetary pinion 42 rotatably supported by the carrier 41 meshes with a sun gear 43 and a ring gear 44. A clutch C0 and a one-way clutch F0 are provided between the sun gear 43 and the carrier 41, and a brake B0 is provided between the sun gear 43 and the housing Hu.

The underdrive section 60 is provided with two front and rear rows of planetary gear units. This planetary gear set has a common sun gear 6.
1, ring gears 62, 63, planetary pinion 64,
65 and carriers 66 and 67.

Ring gear 44 of overdrive section 40
Are connected to the ring gear 62 via a clutch C1. A clutch C2 is provided between the ring gear 44 and the sun gear 61. The carrier 66
Are connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to the output shaft 70.

On the other hand, the carrier 67 and the housing Hu
Are provided with a brake B3 and a one-way clutch F2. A brake B2 is provided between the sun gear 61 and the housing Hu via a one-way clutch F1. Between the sun gear 61 and the housing Hu,
A brake B1 is provided.

This automatic transmission uses a computer (EC
U) 84. The computer 84 has an engine 1
Sensor 80 for detecting the throttle opening degree reflecting the load condition of the vehicle, and vehicle speed sensor 8 for detecting the vehicle speed
A signal such as 2 is input.

Based on the input signal, the computer 84 operates a solenoid valve S in the hydraulic control circuit 86 in accordance with a preset vehicle speed-throttle opening shift pattern.
1. Drive and control S2.

Here, reference numeral 87 denotes a water temperature sensor which detects the temperature of the cooling water of the engine in order to know the warm-up state of the engine. Reference numeral 99 denotes a C0 sensor for detecting the rotational speed of the clutch C0.

In this automatic transmission, as shown in FIG. 5, a combination of engagement of each clutch, brake, and the like is performed to perform a shift. The solenoid valve SL in the figure is used for controlling the lock-up clutch 24 of the torque converter 20. The solenoid valve SD is used for hydraulic control of a specific clutch.

In FIG. 5, ○ indicates that the clutch or brake is engaged, and ◎ indicates that the one-way clutch is locked when power is transmitted from the engine to the wheels. Is shown.

FIG. 6 shows a control flow executed by the computer 84.

In the first embodiment, shifting to the fourth speed (overdrive) is prohibited until the warm-up is completed.

The process shown in FIG. 6 is executed at substantially regular intervals by a timer interrupt.

First, in step 201, it is determined whether or not the current running state is a state that should be the overdrive gear. That is, the throttle opening θ and the vehicle speed N0
It is determined whether or not the current running state is a state that should be the overdrive stage from the above.

If it is determined that the current running state is not a state in which the vehicle should be in the overdrive stage, the routine proceeds to step 205, where the flag F indicating the continuation of shift inhibition is turned off. After that, the process directly proceeds to the end (reset).

On the other hand, if it is determined in step 201 that the vehicle should be in the overdrive stage, the process proceeds to step 202 to determine whether or not the cooling water temperature is 50 ° C. or higher, ie, whether or not the warm-up has been completed. Is determined.

If the cooling water temperature is lower than 50 ° C., that is, if it is determined that the warming-up has not been completed, step 20
The program proceeds to step S4, where the flag F indicating the continuation of the shift prohibition is turned on. Thereafter, the program proceeds to step 207 to maintain the overdrive prohibition state.

Eventually, when the cooling water temperature becomes 50 ° C. or higher,
The process proceeds from step 202 to step 203. In step 203, it is determined whether the flag F indicating the shift prohibition continuation is set to ON.

If the flag F is ON, the process proceeds to step 207, and the overdrive prohibition is maintained as it is.

As described above, the flag F indicates that the current running state is other than the overdrive stage, that is, from the first speed stage to the third speed stage at step 201 based on the vehicle speed and the throttle opening.
Since it is not turned off unless it is determined that the gear is one of the speed stages, it is possible to prevent the shift to the overdrive stage immediately due to the cooling water temperature becoming 50 ° C. or higher.

Once the vehicle is out of the state to become the overdrive stage and the determination of "NO" is made in step 201, the shift prohibition continuation flag F is turned off in step 205.
It is said. Therefore, if the conditions of the overdrive traveling are satisfied thereafter, steps 201, 202, and 203 are each determined to be "YES", so that step 206
And the vehicle can travel in the overdrive stage.

As a result, the shift to the overdrive stage is executed only under exactly the same conditions as usual.
Since this shift is a shift that is performed due to a change in the throttle opening or the vehicle speed, the shift shock is masked to some extent and does not reach a level that causes a problem.

The shift based on the change in the accelerator pedal and the vehicle speed is a shift that can be sufficiently predicted for the driver, and does not give the driver an uncomfortable feeling in this sense.

In the first embodiment, the predetermined shift prohibition condition is that the warm-up has not been completed, and whether the warm-up has been completed is determined by determining whether the engine coolant temperature has reached 50 ° C. or higher. The predetermined shift prohibition condition determining means in the present invention is not limited to this. For example, the predetermined shift prohibition condition may be a determination of incomplete engine warm-up, and may directly detect the temperature of the engine body. Further, even when the cooling water temperature is used, the threshold value is not limited to 50 ° C.

The present invention relates to, for example,
The present invention can be applied to an automatic transmission employing a configuration disclosed in Japanese Patent No. 34257, which permits a shift to a high gear when the vehicle speed is equal to or higher than a predetermined value even before completion of warm-up. It is. In this case, when the vehicle speed is equal to or lower than the predetermined value and the current traveling state is a state where the high speed gear is not originally set because the warm-up has not been completed while the current high speed gear should be originally the high speed gear. The present invention will be applied to this.

FIG. 7 shows an overall outline of a more specific automatic vehicle transmission to which the second embodiment of the present invention is applied.

In the automatic transmission according to the second embodiment of the present invention shown in FIG. 7, the transmission portion of the automatic transmission according to the first embodiment of the present invention shown in FIG. It has the same transmission section.

In the transmission section of the automatic transmission shown in FIG. 7, two transmission sections are organically combined to perform a plurality of gears. In the second embodiment of the present invention shown in FIG. 7, reference numeral 60 indicates a first transmission unit, and reference numeral 40 indicates a second transmission unit.

Further, in order to combine the respective shifts of the first transmission unit 60 and the second transmission unit 40 in this manner to perform a more multi-stage shift, the present invention shown in FIG. In the second embodiment, the processing performed by the hydraulic control circuit 106 and the computer (ECU) 84 is partially different from the first embodiment of the present invention described above.

In the first embodiment of the present invention shown in FIG. 7, reference numerals 1, 10, 20 to 24, 40 to 44, 60 to 6
7, 70, 80, 82, 87, 99, C0 to C2, B0
B3, F0 to F2, and HU are the same as those described above with the same reference numerals in FIG. Also, in FIG.
Reference numeral 112 denotes a shift position sensor for reading a shift position operated by the driver, and reference numeral 112 denotes an oil temperature sensor for detecting the oil temperature of the automatic transmission.

The automatic transmission according to the second embodiment of the present invention shown in FIG.

The computer 84 receives signals from a throttle sensor 80 for detecting a throttle opening reflecting a load state of the engine 1 and a vehicle speed sensor 82 for detecting a vehicle speed.

Based on the input signal, the computer 84 sets a predetermined vehicle speed, which will be described later with reference to FIG.
Hydraulic control circuit 1 according to shift pattern of throttle opening
The solenoid valves S1 to S3 in 06 are driven and controlled.

As a result, as shown in FIG. 8, the combination of engagement of each clutch, brake and the like is performed, and the shift is executed.

The solenoid valve SL shown in FIG. 7 is used for controlling the lock-up clutch 24 of the torque converter 20.

In FIG. 8, ○ indicates that the clutch or brake is engaged, and ◎ indicates that the one-way clutch is locked when power is transmitted from the engine to the wheels. , And the crosses indicate the released state of the clutch, brake or one-way clutch.

In the second embodiment of the present invention, when the operating oil of the automatic transmission is at a low temperature, the intermediate stage (the second stage shown in FIG.
Speed) is prohibited.

That is, when the oil temperature is low, the upshift from the first gear is not performed to the second gear, but the gear is shifted to the third gear under predetermined conditions. The downshift from the third gear is not performed to the second gear, but is shifted to the first gear under predetermined conditions.

This is because when the operating oil is at a low temperature,
This is because the shift control of the upshift from the second speed to the third speed is relatively difficult, and the shift shock is likely to increase.

The basic concept of the control for inhibiting the shifting to the second speed in the second embodiment of the present invention is to inhibit a predetermined intermediate speed or the like due to a slight temporary failure of a rotation sensor or the like. The same can be applied to the case of performing the above.

FIG. 9 shows a control flow executed by the computer 84.

First, at step 401, the oil temperature T of the operating oil of the automatic transmission is detected using the oil temperature sensor 112.

In step 402, the oil temperature T detected in step 401 is compared with a predetermined inhibition level To. That is, when the oil temperature T is equal to or lower than the prohibition level To, it is determined that the operating oil of the automatic transmission is still low, and the process proceeds to step 407. On the other hand, if the oil temperature T is higher than the prohibition level To, the process proceeds to step 403.

In step 403, the shift prohibition flag F
Is set. This shift prohibition flag F is set (corresponding to "1") when the hydraulic oil temperature of the automatic transmission is equal to or lower than To, and when the hydraulic oil temperature exceeds To and a downshift to the second speed is newly performed. When it is determined, it is reset (corresponding to "0"), and thereafter remains reset.

In step 403, the shift prohibition flag F
Is determined to be "1", the process proceeds to step 404.
On the other hand, if it is determined in step 403 that the shift prohibition flag F is “0”, the process proceeds to step 409.

At step 404, the engine load is detected by inputting a signal from the throttle sensor 80 for detecting the throttle opening reflecting the load state of the engine 1.

At step 405, the running speed of the vehicle equipped with this automatic transmission is detected by the vehicle speed sensor 82.

In step 406, the aforementioned step 40
According to the throttle opening, that is, the engine load detected in step 4, and the vehicle speed detected in step 405, the second
It is determined whether or not a downshift to a gear is required. This determination is based on a shift point in FIG. 11 described later.

If it is determined in step 406 that the downshift to the second speed is to be performed, the process proceeds to step 407. On the other hand, if it is determined in step 406 that it is not in the state to perform the downshift to the second speed, the process proceeds to step 409.

In step 407, a second-speed prohibited shift point is set, which will be described later with reference to FIG.

Following step 407, step 408
Then, the shift inhibition flag F is set ("1"), and the entire flow shown in FIG. 9 is completed.

On the other hand, at step 409, a second speed permission shift point is set, which will be described later using FIG.

Following step 409, step 410
Then, the shift prohibition flag F is reset ("0"), and the processing shown in the control flow of FIG. 9 is completed.

According to the control flow of FIG. 9, it is possible to obtain a shift point shown in FIG. 11, which will be described later, in which the setting is partially changed according to the level of the operating oil temperature of the automatic transmission.

FIG. 10 is a second control flow executed by the computer 84 according to the second embodiment of the present invention.

The processing content obtained in the second control flow of FIG. 10 is the same as the processing content of the first control flow of FIG.

In the second control flow of FIG. 10, the control flow showing the gist of the present invention shown in FIG. 2 and the control flow of the first embodiment of the present invention shown in FIG. The correspondence has been made easier.

The second control flow of the second embodiment shown in FIG. 10 has substantially the same processing contents as the first control flow in the method of setting the logical state of the shift inhibition flag F and the like.

That is, in the second control flow of the second embodiment of the present invention shown in FIG. 10, the setting point is partially changed depending on the level of the operating oil of the automatic transmission as shown in FIG. Can be obtained.

That is, in the second control flow, after it is determined that the downshift to the second speed is newly performed after the temperature of the hydraulic oil becomes equal to or higher than To, the shift inhibition flag F
Is always reset, and the shift prohibition flag F is set when the hydraulic oil becomes equal to or more than To for the first time in a state where it is determined that the downshift to the second speed should be performed.

FIG. 11 is a graph of vehicle speed versus throttle opening showing shift points according to the second embodiment of the present invention.

The shift point shown in FIG. 11 is common to the control flow of FIG. 9 and the control flow of FIG.

In FIG. 11, a solid line indicates a shift point during an upshift, and a broken line indicates a shift point during a downshift.

A thick solid line indicates a shift point of an upshift from the first speed to the second speed. A thick broken line indicates a shift point of the downshift from the third speed to the second speed, and this thick broken line corresponds to step 406 of the control flow of FIG. 9 and step 503 of FIG.

In the automatic transmission according to the second embodiment of the present invention, shifting to the second speed is prohibited when the operating oil temperature of the automatic transmission is equal to or lower than To.

Therefore, when the operating oil is lower than To, the shift point indicated by the thick solid line and the shift point indicated by the thick broken line in FIG. 11 are not used. As a result, when the oil temperature is low, there is no upshift from the second speed to the third speed, and the upshift to the third speed is performed from the first speed. Similarly, at low temperatures, there is no downshift from the second gear to the first gear, and the third gear is downshifted to the first gear.

For example, when the operating oil temperature of the automatic transmission is equal to or lower than To, the state of the vehicle speed and the state of the throttle opening are shown in FIG.
When the operating oil temperature rises in the region indicated by the symbol * A of 1, the downshift from the third speed to the second speed is not performed, and the third speed is shifted to the first speed. No downshift is performed.

Thereafter, when the vehicle speed once increases and enters the region indicated by the symbol * B, and then the vehicle speed decreases again to the region indicated by the symbol * A, in the present embodiment, the third speed is established. From the second
A downshift to a gear is performed.

Alternatively, when the state of the vehicle speed and the state of the throttle opening are within the range of the symbol * A and the hydraulic oil is equal to or greater than To, and the shift from the third speed to the second speed is prohibited, the symbol * In the area C, a downshift from the third speed to the first speed is performed.

The change (setting) of the shift point with respect to the thick solid line and the thick broken line in FIG. 11 is performed in step 407 or 409 of the control flow of FIG. 9 or in step 509 or step 510 of the control flow of FIG. Done.

As described above, according to the second embodiment of the present invention,
Downshifting and upshifting to the second speed stage when the operating oil temperature of the automatic transmission exceeds To is performed when the throttle opening and the vehicle speed change. Therefore, the shift based on such a change in the accelerator pedal and the vehicle speed is a shift that can be sufficiently predicted for the driver, and thus does not give a sense of incongruity to the driver in this sense.

Although the shift to the second speed is prohibited in the second embodiment, the present invention is not limited to this. Further, in the second embodiment, the shift prohibition condition is set when the hydraulic oil of the automatic transmission is equal to or less than To. However, the shift prohibition condition of the present invention is not limited to this. A shift prohibition condition may be such that a shift to a predetermined shift speed is prohibited due to a minor temporary failure of a rotation sensor or the like that detects the rotation speed of the member.

[0100]

As described above, according to the present invention, when the accelerator opening and the vehicle speed are constant and the vehicle is in a stable running state, the shift is detected together with the detection of the failure of the predetermined shift prohibition conditions such as the completion of warm-up. The shift to the prohibited gear stage is executed, and the occurrence of a large shift shock can be prevented.

Further, it is also possible to prevent a sudden shift shock from occurring when the driver does not intend, and to prevent the driver from feeling uncomfortable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a flowchart showing the gist of the present invention.

FIG. 3 is a block diagram showing the gist of the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of an automatic transmission for a vehicle to which the first embodiment is applied;

FIG. 5 is a diagram showing an engaged / disengaged state of the friction engagement device of the automatic transmission according to the first embodiment.

FIG. 6 is a flowchart showing a control flow executed in the automatic transmission according to the first embodiment.

FIG. 7 is a schematic configuration diagram of an automatic transmission for a vehicle to which a second embodiment of the present invention is applied;

FIG. 8 is a diagram showing an engaged / disengaged state of the friction engagement device of the automatic transmission according to the second embodiment.

FIG. 9 is a flowchart showing a first control flow executed in the automatic transmission according to the second embodiment.

FIG. 10 is a flowchart showing a second control flow executed in the automatic transmission according to the second embodiment.

FIG. 11 is a graph of vehicle speed-throttle opening showing shift points of the automatic transmission according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine, 80 ... Throttle sensor, 82 ... Vehicle speed sensor, 84 ... Computer, 87 ... Engine cooling water temperature sensor.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideaki Ohtsubo 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Noriaki Asahara 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yasuo Hojo 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-61-119427 (JP, A) JP-A-2-253052 (JP, A) Hei 2-225872 (JP, A) JP-A-58-203255 (JP, A) JP-A-58-34257 (JP, A) JP-A-61-228148 (JP, A) JP-A-62-177356 (JP, A) JP-A-2-296066 (JP, A) JP-A-2-29667 (JP, A) JP-A-2-266158 (JP, A) JP-A-62-103225 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 59/00-6 1/12 F16H 61/16-16/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] A shift to a specific gear corresponding to the shift prohibition condition is prohibited while a predetermined shift prohibition condition is satisfied, and the shift to the specific shift speed is permitted while the shift prohibition condition is not satisfied. A shift request state determining unit that determines whether a current traveling state is a shift request state that should be the specific shift speed, and determines whether the predetermined shift inhibition condition is satisfied or not. A shift prohibition condition determining means for judging, and when the predetermined shift prohibition condition is not satisfied under the shift request state, the specific gear position is deviated from the shift request state once and is returned to the shift request state again. A shift control device for an automatic transmission, comprising: shift prohibition means for continuing to prohibit shift to a transmission.