JP3458708B2 - 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, and more particularly to a shift control technique during deceleration of a vehicle.

[0002]

2. Description of the Related Art An automatic transmission is, for example, Nissan Motor Co., Ltd.
"NISSAN RE4R" issued in March 1987 by
01A full-range electronically controlled automatic transmission maintenance manual ”(A261C07), the driver uses the shift lever to set the manual valve to the automatic speed change (D) range or the second speed engine brake (I
Power transmission of the gear transmission system by selectively engaging a plurality of friction elements for shifting such as a clutch and a brake during the forward traveling range such as the I) range and the first speed engine brake (I) range. By determining the path (shift stage), power can be transmitted from the input shaft to the output shaft at the selected shift stage, and by shifting the friction element to be engaged, shifting to another shift stage is performed. Constitute.

In determining the gear stage to be selected here, it is usually described in the above-mentioned document, but FIG.
As illustrated in FIG. 6, a shift pattern (solid line is an upshift shift line, broken line is a downshift shift line, which is set in advance for each range on the condition of at least the vehicle speed VSP (normally, a combination of this and the throttle opening TVO). It is customary to determine the gear stage to be selected by the gear shift judgment based on (1).

By the way, at the time of shifting to the shift speed determined in this way, a plurality of shift valves are stroked to switch the oil passages, thereby changing the friction elements to be engaged, thereby changing to the determined shift speed. Since gear shifting is performed, it is unavoidable that a gear shift response delay occurs before the gear stage to be selected is determined by the gear shift determination and the gear shifting to this gear stage is actually performed. Therefore, although the shift is determined according to the schedule defined by the shift line, the actual shift cannot be performed at the vehicle speed defined by the shift line during the relatively rapid acceleration or deceleration. However, the actual shift does not occur according to the schedule defined by the shift line, and the driver feels uncomfortable.

This tendency becomes particularly noticeable during rapid deceleration in which the time change rate of the vehicle speed can be made large, and the above-mentioned uncomfortable feeling becomes unacceptable. Therefore, conventionally, when the vehicle is decelerated as described in Japanese Patent Laid-Open No. 3-103661, a look-ahead vehicle speed on the low vehicle speed side is calculated according to the vehicle deceleration rather than the actual vehicle speed, and the look-ahead vehicle speed is used to shift gears based on the look-ahead vehicle speed. A shift control technique has been proposed that makes a judgment. According to this shift control, it is possible to make an early shift determination in anticipation of a shift response delay during deceleration, and prevent an actual downshift due to deceleration from occurring at a vehicle speed lower than the schedule defined by the shift line. can do.

[0006]

By the way, in the II range and the I range, as shown in FIGS. 5 and 6, respectively, comparison with the shift pattern for the D range (including the OD prohibition state) shown in FIG. Obviously, the downshift (3 → 2, 2 → 1) shift line is shifted to a higher vehicle speed side than the corresponding downshift shift line in the D range, and the gear position for engine braking (second speed, first speed) Set the shift pattern so that it is selected as long as possible. However, if the downshift (3 → 2, 2 → 1) shift line is shifted to the high vehicle speed side, the engine speed inevitably increases, and therefore,
Downshift of II range and I range (3 → 2, 2 →
1) When shifting the shift lines to the high vehicle speed side, it is usual to shift them to the high vehicle speed side as far as possible within a range where engine over-rotation does not occur.

Therefore, even if the shift range is determined based on the read-ahead vehicle speed even in the II range and the I range, the downshift shift line is shifted to the high vehicle speed side to the maximum extent in the range where engine over-rotation does not occur. However, there is a problem that the downshift is executed early (when the vehicle speed is high) by the shift determination based on the look-ahead vehicle speed, and the possibility that the engine overspeeds increases accordingly.

A first invention according to claim 1 proposes a shift control device for an automatic transmission, which solves the above-mentioned problem in the case of making a shift determination based on a look-ahead vehicle speed in a range in which a downshift shift line is shifted to a high vehicle speed side. The purpose is to do.

According to a second aspect of the present invention, in the first aspect of the present invention, the conventional automatic shift determination that enables the conventional shift determination based on the look-ahead vehicle speed in a range other than the range in which the downshift transmission line is shifted to the high vehicle speed side is provided. An object of the present invention is to propose a shift control device for a transmission.

It is an object of a third aspect of the present invention to propose a shift control device for an automatic transmission that eliminates the adverse effect that the look-ahead vehicle speed decreases beyond an allowable range.

It is an object of a fourth aspect of the present invention to propose a shift control device for an automatic transmission in which an allowable lower limit value of the read-ahead vehicle speed can be set to a suitable value for each selected shift stage.

[0012]

For these purposes, first, a shift control device for an automatic transmission according to a first aspect of the present invention shifts gears based on a shift determination based on a shift line for each range, which is preset on the condition of at least vehicle speed. In the automatic transmission shift control device, which is used for an automatic transmission to perform deceleration of the vehicle, the shift control device of the automatic transmission is configured to make a shift determination based on the shift line by a look-ahead vehicle speed that is lower than the actual vehicle speed. In the range in which the downshift shift line is shifted to the high vehicle speed side, the shift determination is made based on the actual vehicle speed, not on the look-ahead vehicle speed even during deceleration.

Also, in the shift control device for an automatic transmission according to the second invention, in the first invention, the look-ahead vehicle speed is determined according to the vehicle deceleration, and the downshift transmission line is in a range other than the range shifted to the high vehicle speed side. During normal deceleration in which the look-ahead vehicle speed is equal to or higher than the limit vehicle speed obtained by subtracting the set value from the actual vehicle speed, the shift determination is performed based on the look-ahead vehicle speed.

In the shift control device for an automatic transmission according to the third aspect of the present invention, in the second aspect of the present invention, the look-ahead vehicle speed obtained in accordance with the vehicle deceleration becomes less than a limit vehicle speed obtained by subtracting a set value from the actual vehicle speed. At the time of deceleration, the read-ahead vehicle speed is configured so that the read-ahead vehicle speed is a read-ahead vehicle speed allowable lower limit value obtained by subtracting a constant vehicle speed smaller than the set value from the actual vehicle speed.

A shift control device for an automatic transmission according to a fourth aspect of the invention is characterized in that, in the third aspect of the invention, the constant vehicle speed is made different for each selected shift stage.

[0016]

According to the first aspect of the invention, the automatic transmission shifts gears based on at least the vehicle speed for each range on the basis of a preset shift line, and when the vehicle is decelerated, the vehicle speed is lower than the actual vehicle speed. The shift determination based on the shift line is performed according to the look-ahead vehicle speed. Therefore, at the time of deceleration, the shift judgment is made early in consideration of the shift response delay, and it is possible to prevent the actual downshift due to deceleration from occurring at a vehicle speed lower than the schedule defined by the shift line. . Therefore, the actual gear shift can always be performed at the vehicle speed according to the schedule defined by the shift line regardless of the vehicle deceleration, and when the vehicle decelerates, the actual gear shift varies depending on the degree of deceleration. The problem of occurring at vehicle speed can be avoided.

In the first aspect of the invention, in particular, in the range in which the downshift transmission line deviates to the high vehicle speed side, the shift determination is made based on the actual vehicle speed during deceleration regardless of the preread vehicle speed. If the shift is determined based on the look-ahead vehicle speed during deceleration in the range, the downshift due to the deceleration occurs early as described above, and the downshift transmission line is set to the highest level in the range where engine overspeed does not occur in the range. Since it is a common practice to shift to the vehicle speed side, it is easy to cause over-engine rotation that is absolutely desired to be avoided, but in the first aspect of the present invention, such over-engine rotation can be surely eliminated. Is obtained.

According to the second aspect of the invention, the look-ahead vehicle speed is obtained according to the vehicle deceleration, and the look-ahead vehicle speed is obtained by subtracting the set value from the actual vehicle speed in a range other than the range in which the downshift transmission line is shifted to the high vehicle speed side. During normal deceleration that is equal to or higher than the limit vehicle speed, the shift determination is performed based on the look-ahead vehicle speed.
The shift determination as described above can be performed based on the look-ahead vehicle speed in a range other than the range in which the downshift transmission line is shifted to the high vehicle speed side.

According to the third aspect of the invention, when the look-ahead vehicle speed obtained according to the vehicle deceleration is less than the limit vehicle speed obtained by subtracting the set value from the actual vehicle speed, the vehicle speed is deviated from the set value from the actual vehicle speed during the rapid deceleration. Since the read-ahead vehicle speed is the read-ahead vehicle speed allowable lower limit value obtained by subtracting a small constant vehicle speed,
It is possible to prevent the look-ahead vehicle speed from exceeding the lower limit of the look-ahead vehicle speed and to prevent the shift from becoming unnatural because the shift determination or the engagement / disengagement determination of the friction element for the engine brake becomes too fast. .

In the fourth aspect of the invention, the constant vehicle speed in the third aspect of the invention is made different for each selected shift stage, so that the lower limit of the pre-reading vehicle speed can be set to a suitable value for each shift stage, and at any shift stage. 4 The effects of the invention can be reliably achieved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an automatic transmission equipped with a shift control device according to an embodiment of the present invention, in which 1 is an engine, 2 is a torque converter, 3 is an automatic transmission, and the engine rotation passes through a torque converter 2. It shall be transmitted to the input shaft 4 of the automatic transmission.

The automatic transmission 3 is basically the same as that described in "RE4R01A type automatic transmission maintenance manual" (A261C07) issued by Nissan Motor Co., Ltd., and the input and output arranged in a coaxial butting relationship. A front planetary gear set 6 and a rear planetary gear set 7 are mounted on the shafts 4 and 5.

Further, the forward clutch F / C, the high clutch H / C, the band brake B / B, the low one-way clutch L / OWC, the forward one-way clutch F / OWC, and the reverse clutch R / C are provided as the friction elements for shifting. , Further rowan way clutch L / O
Low reverse brake LR / in parallel with WC
B, and an overrun clutch OR / C provided in parallel with the forward one-way clutch F / OWC, and by selectively engaging these friction elements in a combination indicated by a circle in FIG. 1st to 4th
The speed and the reverse gear can be selected.

2 (b) relating to the low reverse brake LR / B and the overrun clutch OR / C indicates that when engine braking is required in the first to third speeds (the driver will be described later). 3 by OD prohibition switch 13
(When commanding a high speed engine brake or, for details, a second speed engine brake or a first speed engine brake is commanded by selecting the II range or I range of a manual valve (not shown) via a shift lever 15 described later)
Indicates that the low reverse brake L
The R / B and the overrun clutch OR / C each constitute a friction element for engine braking. By the way, the fourth
In the case of FIG. 1, the speed is the gear train in which the engine braking is effective, and there is no engine braking friction element for the fourth speed.

Further, in order to execute the selective operation (engagement) of the friction element, particularly in the present embodiment, it is inserted into the control valve 8 of the automatic transmission 3 to shift gears A and B and the overrun. Clutch solenoid 1
0, and the control valve 8 is further provided with a line pressure solenoid 11 inserted therein for controlling a line pressure which is a hydraulic pressure for engaging and operating the friction elements of the automatic transmission. Then, the automatic transmission 3 controls the shift solenoids A and B to be a combination of ON (generation of solenoid pressure) and OFF (disappearance of solenoid pressure) shown in FIG. It is assumed that the friction elements F / C, H / C, B / B are selectively engaged according to the engagement logic of FIG. 2B so that the fourth speed is selected.

The low reverse brake LR / B and the reverse clutch R / C are set when the driver sets the shift lever 15 to the first speed engine brake (I) range position or the reverse running (R) range position, respectively. A hydraulic pressure is supplied from a port of a manual valve (not shown) that is interlocked with the engine, and is engaged in a predetermined manner to engage the engine brake at the first speed with the engagement of the low reverse brake LR / B and the overrun clutch described later. The OR / C is engaged, and the reverse gear is selected by engaging the low reverse brake LR / B and the reverse clutch R / C. Overrun clutch OR here
/ C is the O of the overrun clutch solenoid 10
It is assumed that the clutch is engaged by FF (disappearance of solenoid pressure) and released by turning on (generation of solenoid pressure) of the overrun clutch solenoid 10.

Further, the line pressure solenoid 11 is supposed to increase the line pressure of the automatic transmission by increasing the ON duty.

The ON / OFF of the solenoids A, B, 10 and the drive duty of the solenoid 11 are controlled by the controller 1.
4 and the controller selects the range selected by the shift lever 15 and the OD (fourth range).
Signal from the range sensor 16 that detects the third speed engine braking command from the speed prohibiting switch 13 and the engine 1
Signal from a throttle opening sensor 17 for detecting the throttle opening TVO, a signal from a vehicle speed sensor 18 for detecting the vehicle speed VSP, and an acceleration sensor 19 for detecting an acceleration (negative value represents deceleration) G of the vehicle. From the idle switch, a signal from the idle switch that is turned on when the accelerator pedal is released, and a signal from the brake switch 21 that is turned on when the brake pedal is depressed.

Shift lever 15 and range sensor 16
The supplementary explanation of the shift lever 15 will be made as described in the above-mentioned literature, and the parking (P) range position, the backward traveling (R) range position, the neutral (N) range position, and the forward automatic shift (D) are well known. ) The range position, the second speed engine brake (II) range position, and the first speed engine brake (I) range position are arranged in a straight line, and the OD (fourth speed) prohibition switch 13 is turned on in the D range. In this case, it is assumed that the shift to the 4th speed is prohibited and the engine braking at the 3rd speed can be obtained.

The range sensor 16 outputs to the controller 14 a signal indicating where in the range position the shift lever 15 is operated, and at the same time OD (4th speed).
A 3-speed engine brake command from the prohibiting switch 13 is output to the controller 14.

While the vehicle is traveling forward, the controller 14 executes the control program of FIG. 3 on the basis of the above-mentioned input information, and the following friction elements (overrun clutch OR / C) for engine braking, which is the object of the present invention, is targeted. Gear change control including engagement / release control during gear change shall be performed. First, in step 31, based on the signal from the range sensor 16, OD
(4th speed) It is determined whether the D range includes the prohibited state or the I range or II range other than the above.

If it is in the D range, in step 32, it is judged whether or not the vehicle speed range in which the shift control during deceleration aimed by the present invention is to be performed, that is, whether the vehicle speed VSP is less than a predetermined vehicle speed VSP _S , and then in step 33. , And determines whether other conditions for performing deceleration shift control are met. Here, the other deceleration shift control conditions are that the idle switch 20 is turned on by releasing the accelerator pedal, the brake pedal is depressed and the brake switch 21 is turned on.
It means three conditions that the vehicle acceleration G detected by the above is a negative value representing deceleration, and the deceleration shift control is performed when these three conditions are met.

If the vehicle speed conditions in step 32 are not met, or if the three conditions in step 33 are not met, step 3
4, based on the corresponding upshift and downshift lines in the shift map illustrated in FIG. 4 for the D range, it is determined whether the vehicle speed detection value VSP should be upshifted or downshifted. In order that a shift corresponding to the upshift shift determination and the downshift shift determination be executed, that is, the engagement / release switching of the friction element for the shift is performed based on the engagement logic of FIG. 2B. The solenoids A and B are switched on and off based on the logic of 2 (a). However, OD
When the third speed engine brake command is received by turning on the (fourth speed) prohibition switch 13, the shift control is performed so that the shift to the fourth speed does not occur.

Next, if there is the third speed engine brake command, in step 35, based on the unillustrated engagement area map of the friction element (overrun clutch OR / C) for engine braking, the friction is calculated from the vehicle speed detection value VSP. The element engagement / disengagement determination is performed, and the engine brake friction element (overrun clutch OR is appropriately performed according to the determination result.
/ C) is controlled so that the overrun clutch solenoid 10 is turned OFF and ON so that the third speed engine brake can be obtained.

When it is determined in step 33 that the gear shift control conditions during deceleration are complete, in step 36, from the vehicle speed detection value VSP which can be obtained in the same manner as described in the above-mentioned Japanese Patent Laid-Open No. 3-103661. Also checks the look-ahead vehicle speed VSP _INC on the low vehicle speed side according to the vehicle deceleration G. This look-ahead vehicle speed VSP _INC is the vehicle speed detection value VSP
Limit vehicle speed by subtracting a set value DerutaVSP _L from (VSP-
ΔVSP _L ) or more (VSP−ΔVSP _L ≦ V
If SP _INC <VSP, that is, during normal deceleration that produces a deceleration of a normal degree, then in step 37, the corresponding upshift and downshift shift lines in the shift map illustrated in FIG. Based on the read-ahead vehicle speed VSP _INC, whether to upshift or downshift is determined, and a shift corresponding to the upshift shift determination and the downshift shift determination is executed, that is, in FIG. 2B. Based on the engagement logic, engagement / release switching of the friction element for the gear shift is performed.
ON / O of solenoids A and B based on the logic of FIG.
FF switching is performed.

Next, at step 38, the look-ahead vehicle speed VSP is determined based on an unillustrated engagement area map of the friction element (overrun clutch OR / C) for engine braking.
Performing the engagement / disengagement determination of the friction element from _INC, and appropriately controlling the OFF / ON of the overrun clutch solenoid 10 to engage / disengage the friction element (overrun clutch OR / C) for engine braking according to the determination result. So that the engine brake at the selected gear can be obtained.

By the way, in the present embodiment, when the vehicle is normally decelerated as in step 37, the look-ahead vehicle speed VSP _INC on the low vehicle speed side corresponding to the vehicle deceleration G is higher than the actual vehicle speed VSP.
Since the shift determination based on the shift line is performed by the shift line, the shift determination is made earlier in anticipation of the shift response delay during the normal deceleration, and the actual downshift due to deceleration is less than the schedule defined by the shift line. It can be prevented from occurring at a low vehicle speed. Therefore, regardless of the vehicle deceleration G, the actual gear shift can always be performed at the vehicle speed according to the schedule defined by the shift line, and when the vehicle decelerates, the actual gear shift varies depending on the degree of deceleration. It is possible to avoid the problem that occurs at the vehicle speed of.

Further, in the present embodiment, in the case of the normal deceleration in which the shift determination is performed by the look-ahead vehicle speed VSP _{INC as} described above, the engagement / release determination of the engine brake friction element (overrun clutch OR / C) is performed as in step 38. The pre-read vehicle speed VSP _INC is also used. Therefore, during normal deceleration of the vehicle in which the pre-read vehicle speed VSP _INC makes the shift determination early, the look-ahead vehicle speed VSP _{INC also} makes the early decision on the engagement / release of the friction element for engine braking. Therefore, the engagement of the gear shift friction element for downshifting accompanying deceleration is preceded by the release of the engine brake friction element (overrun clutch OR / C) that should be released for gear shift shock countermeasures during the gear shift. Therefore, it is possible to reduce the possibility that gear shift shock will increase.

Moreover, the operation and effect can be achieved only by correcting the vehicle speed for obtaining the look-ahead vehicle speed VSP _INC from the actual vehicle speed VSP, and for increasing the engagement vehicle speed of the friction element (overrun clutch OR / C) for engine braking. Since the correction operation is unnecessary, the control can be simplified and the time required for the control can be shortened.

Look-ahead vehicle speed VSP in step 36
_{When the} vehicle has a rapid deceleration in which the _INC determination result is VSP _INC <VSP-ΔVSP _L , the selected shift speed determined from ON / OFF of the shift solenoids A and B in step 39 is the first speed or the second speed. In step 40, the pre-read vehicle speed is the pre-read vehicle speed allowable lower limit value (VSP-ΔVSP _C1 ) obtained by subtracting the constant vehicle speed ΔVSP _C1 for the first speed or the second speed smaller than the above-mentioned ΔVSP _L from the vehicle speed detection value VSP, Based on this, the same gear shift determination and gear shift as in step 37 are performed.

Next, at step 41, the same allowable lower limit value (VSP-ΔVSP _C1 ) of the pre-read vehicle speed is set as the pre-read vehicle speed, and based on this, the same friction element for engine braking (overrun clutch OR /
C) The engagement / release determination and the engagement / release based on the determination result are performed.

If the selected speed determined in step 39 is the third speed or the fourth speed, the constant vehicle speed for the third speed or the fourth speed smaller than the above-mentioned ΔVSP _L is detected from the vehicle speed detection value VSP in step 42. The read-ahead vehicle speed allowable lower limit value (VSP−ΔVSP _C2 ) obtained by subtracting ΔVSP _C2 is set as the read-ahead vehicle speed, and based on this, the same shift determination and shift as in step 37 are performed. Next, at step 43, the same permissible lower limit of the pre-read vehicle speed (VSP-Δ
VSP _C2 ) is set as the look-ahead vehicle speed, and based on this, the engagement / disengagement determination of the friction element (overrun clutch OR / C) for engine braking similar to that in step 38 and the engagement / disengagement based on the determination result are performed.

In the present embodiment, the look-ahead vehicle speed VS
In the case of rapid deceleration where P _INC becomes smaller than (VSP−ΔVSP _L ), as in steps 40 and 42, the constant vehicle speed ΔV smaller than the set value ΔVSP _L from the actual vehicle speed VSP.
The read-ahead vehicle speed falls below the read-ahead vehicle speed allowable lower limit value because the read-ahead vehicle speed allowable lower limit value obtained by subtracting SP _C1 and ΔVSP _C2 is used as a read-ahead vehicle speed for gear shift determination and engine brake friction element engagement / release determination. It is possible to prevent the shift from becoming unnatural because the shift determination and the engagement / disengagement determination of the friction element for engine braking become too early.

Further, the constant vehicle speeds ΔVSP _C1 , ΔVS
P _C2 is selected for each gear (first speed and second speed, and third speed
Since the read-ahead vehicle speed allowable lower limit value can be set to a suitable value for each gear, since the speed and the fourth gear are different, it is possible to reliably achieve the above-described operational effects at any gear.

Look-ahead vehicle speed VSP in step 36
_If the result of _INC determination is VSP _INC ≧ VSP, the vehicle is traveling at a constant speed or accelerating and is not subject to the shift control during deceleration, so the control is of course advanced to steps 34 and 35.

In step 31, the II range and the I range in which the downshift transmission line is shifted to the higher vehicle speed side than the downshift transmission line for the D range in FIG. 4 are selected as shown by the broken lines in FIGS. 5 and 6. If it is determined that the vehicle speed is VSP, the control proceeds to steps 34 and 35 regardless of whether the vehicle is decelerating or not.
Instead of using _INC , the vehicle speed detection value VSP
Also, the shift determination based on the shift pattern of FIG. 6 and the engagement / disengagement determination of the friction element for engine braking are performed.

Here, if the look-ahead vehicle speed VSP _{INC is used} to make a shift determination during deceleration in the II range and I range where the downshift transmission line is shifted to the high vehicle speed side, the downshift due to deceleration occurs early as described above. In that range, it is common practice to shift the downshift line to the high vehicle speed side within the range where engine over-rotation does not occur, so it is easy to avoid engine over-rotation that you absolutely want to avoid. Absent.

Therefore, in the present embodiment, when the gear change judgment based on the gear change patterns of FIGS. 5 and 6 is performed in the II range and the I range, the actual vehicle speed VSP does not depend on the look-ahead vehicle speed VSP _INC even during deceleration. As a result, the downshift due to deceleration can be prevented from occurring at an early stage, and therefore the above-mentioned over-revolution of the engine, which should be absolutely avoided, can be completely eliminated.

[Brief description of drawings]

FIG. 1 is a shift control system diagram of an automatic transmission including a shift control device according to an embodiment of the present invention.

2A and 2B are operation logic diagrams of the same automatic transmission, in which FIG. 2A is a drawing showing a relationship between ON / OFF of a shift solenoid and a selected shift speed, and FIG. 2B is engagement of a selected shift speed and a friction element. It is a figure showing the relationship of.

FIG. 3 is a flowchart showing shift pressure control executed by a controller in the automatic transmission.

FIG. 4 is a shift pattern diagram illustrating an upshift shift line and a downshift shift line for the D range.

FIG. 5 is a shift pattern diagram illustrating an upshift shift line and a downshift shift line for the II range.

FIG. 6 is a shift pattern diagram illustrating an upshift shift line and a downshift shift line for the I range.

[Explanation of symbols]

1 Engine 2 Torque Converter 3 Automatic Transmission 4 Input Shaft 5 Output Shaft 6 Front Planetary Gear Set 7 Rear Planetary Gear Set 8 Control Valve A Shift Solenoid B Shift Solenoid 10 Overrun Clutch Solenoid 11 Line Pressure Solenoid 13 OD Prohibition Switch 14 Controller 15 Shift Lever 16 Range sensor 17 Throttle opening sensor 18 Vehicle speed sensor 19 Acceleration sensor 20 Idle switch 21 Brake switch F / C Forward clutch (Friction element for shifting) H / C High clutch (Friction element for shifting) B / B Band brake (For shifting) Friction element) LR / B Low reverse brake OR / C Overrun clutch (friction element for engine brake) L / OWC Low one-way clutch F / OWC Forward one-way clutch

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-1-229145 (JP, A) JP-A-10-110816 (JP, A) JP-A-3-103661 (JP, A) JP-A-4- 78370 (JP, A) JP 10-103494 (JP, A) JP 9-42438 (JP, A) JP 10-89455 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-61/22 F16H 61/16-61/24 F16H 63/40-63/48

Claims (4)

(57) [Claims] 1. An automatic transmission that shifts according to a shift determination based on a shift line for each range, which is preset with at least the vehicle speed as a condition, and when the vehicle is decelerated, a look-ahead ahead of the actual vehicle speed is lower than the actual vehicle speed. In a shift control device for an automatic transmission configured to determine a shift based on the shift line depending on a vehicle speed, in a range in which the downshift shift line is deviated to a high vehicle speed side among the ranges, even when deceleration No
A shift control device for an automatic transmission, characterized in that the shift determination is made according to an actual vehicle speed. 2. The read-ahead vehicle speed according to claim 1,
Calculated according to both decelerations, and the downshift line is on the high vehicle speed side.
The read-ahead vehicle speed is the actual vehicle speed in a range other than the range
It is above the limit vehicle speed obtained by subtracting the set value from
A shift control device for an automatic transmission, characterized in that the shift determination is made based on the look-ahead vehicle speed during deceleration . 3. The vehicle according to claim 2 , wherein the vehicle deceleration is applied.
The look-ahead vehicle speed obtained by subtracting the set value from the actual vehicle speed
At the time of sudden deceleration that is less than the limit vehicle speed obtained by the above, the pre-read vehicle speed is configured so that the pre-read vehicle speed is set to the pre-read vehicle speed allowable lower limit value obtained by subtracting a constant vehicle speed smaller than the set value from the actual vehicle speed. Gear change control device for transmission. 4. The shift control device for an automatic transmission according to claim 3 , wherein the constant vehicle speed is different for each selected shift stage.