JP6447182B2 - Control device for automatic transmission and shifting method for automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission control device and an automatic transmission shifting method, and more particularly, to an automatic transmission control device and an automatic transmission that realize acceleration by a kickdown operation intended by a driver during automatic shifting. The present invention relates to a speed change method.

  One of the shifting operations of the automatic transmission is a kick-down operation that lowers the gear stage by one step, that is, downshifts the gear stage when the driver depresses the accelerator pedal to accelerate.

  In this regard, a kickdown switch that detects further depression of the accelerator pedal beyond the full opening of the accelerator opening is provided, and when the driver intends to kick down, that is, there was further depression of the accelerator pedal. In some cases, a device capable of downshifting with the stepping operation as a kickdown operation has been proposed (see, for example, Patent Document 1).

  This device makes it possible to perform the kickdown operation intended by the driver by using a kickdown switch. On the other hand, the kickdown operation is performed in a situation where the vehicle speed and the accelerator opening are near the upshift line. Then, since a so-called shift busy state occurs in which the upshift is performed immediately after the downshift, there is a problem that fuel consumption and drivability deteriorate.

  Therefore, the inventor of the present invention provides a dead zone having a preset vehicle speed width in the vehicle speed axis direction from the high opening vehicle speed, which is the vehicle speed when the accelerator opening in the upshift line is fully opened, to the low vehicle speed side. When the kick down switch is turned on in the dead zone, control to prohibit downshifting of the gear stage is performed, and when the kick down switch is turned on at a lower vehicle speed than the dead band range, the gear stage is lowered. A control device for an automatic transmission has been devised which performs a control for executing a shift.

  According to this control device, when a kick-down operation occurs in the dead zone, the shift stage is not downshifted, so shift busy can be avoided.

  On the other hand, the control device for an automatic transmission includes a shift map for a normal mode and an eco-mode shift map in which the high opening side of the upshift line is set at a lower speed than the upshift line of the normal mode shift map. Some have a plurality of shift maps, and switch between them to upshift and downshift the shift stage of the automatic transmission.

  When the inventor of the present invention provides the dead zone for the plurality of shift maps, the gap between the downshift line and the dead zone becomes narrow, particularly in the eco-mode shift map. I discovered a new problem that acceleration by kickdown operation may not be realized.

JP 2013-87782 A

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device for an automatic transmission and a speed change method for the automatic transmission that realize acceleration by a kick down operation intended by the driver during automatic gear shifting. Is to provide.

  In order to solve the above problems, an automatic transmission control device according to the present invention includes a plurality of shift maps in which an upshift line and a downshift line based on a vehicle speed and an accelerator opening of an accelerator pedal are set for each shift stage. In the automatic shift, the control to execute the upshift and downshift of the shift stage of the automatic transmission using the selected shift map, and can be depressed even if the accelerator opening exceeds the full opening Connected to a kickdown switch provided in the accelerator pedal, when a kickdown operation is performed in which the accelerator pedal is depressed beyond the full opening of the accelerator opening, and the kickdown switch is turned on, In the control device for an automatic transmission that performs control to perform a downshift of the shift speed, the accelerator opening degree in the upshift line A dead zone with a preset vehicle speed range in the vehicle speed axis direction is provided on the low vehicle speed side from the high opening vehicle speed, which is the vehicle speed when fully open, and the kick down switch is turned on in the dead zone, and the gear position is lowered. Before executing the control for prohibiting the shift, after selecting a shift map in which the distance between the downshift line and the dead zone is wider than the currently selected shift map, and switching to the shift map, It is characterized in that the control for executing the downshift of the gear stage is performed, and the control for prohibiting the downshift of the gear stage due to the dead zone of the shift map before the switching is avoided.

  Further, in the automatic transmission speed change method of the present invention for solving the above-described problems, an upshift line and a downshift line based on the vehicle speed and the accelerator opening of the accelerator pedal are set for each shift stage during the automatic shift. In the shift method of the automatic transmission for upshifting and downshifting the shift stage of the automatic transmission by switching a plurality of shift maps, the vehicle speed at the time when the accelerator opening at the upshift line is fully opened is high open. When a downshift of the gear position is prohibited due to a kick-down operation in which the accelerator pedal is depressed beyond the full opening of the accelerator opening in a dead zone provided from the vehicle speed to the low vehicle speed side, the gear speed is reduced. Before the shift is prohibited, a shift map in which the distance between the downshift line and the dead band is set wider than the currently selected shift map. After switching to, down-shift the gear position is a method which is characterized in that to avoid the prohibition of downshifting gear by the dead zone of the shift map before being switched.

  According to the automatic transmission control device and the automatic transmission shift method of the present invention, when the kick down switch is turned on in the dead band, the down shift line and the dead band are prohibited before the downshift of the shift stage is prohibited. The driver shifts down the shift stage after switching to a wider shift map between the two and avoids the prohibition of shifting down the shift stage due to the dead zone of the shift map before the shift. Acceleration can be achieved by the intended kickdown operation.

  In particular, the present invention uses a shift map in which the distance between the downshift line and the dead band is set narrow, that is, a shift map with higher fuel efficiency than the high opening side of the upshift line is set to a lower speed side. It is suitable for driving, usually when driving with good fuel efficiency, and when the driver wants acceleration, the acceleration can be realized, so that the overall fuel efficiency can be improved and the drivability deteriorates Can be suppressed.

It is explanatory drawing which illustrates embodiment of the control apparatus of the automatic transmission of this invention. It is explanatory drawing of the shift map of the normal mode of FIG. It is explanatory drawing of the shift map of the eco mode of FIG.

  The automatic transmission control device and the automatic transmission shifting method of the present invention will be described below. FIG. 1 illustrates the configuration of an embodiment of a control device 20 for an automatic transmission 14 according to the present invention. The control device 20 performs control to execute upshift and downshift of the shift stage of the automatic transmission based on the shift map M1 and the kickdown switch 24 during automatic shift.

  As shown in FIG. 1, in the vehicle 10 including the automatic transmission 14, the power of the engine 11 is transmitted to the fluid coupling (fluid coupling) 12, and the clutch (friction engagement element) 13 is transmitted from the fluid coupling 12. Is transmitted to the automatic transmission 14. Then, it is transmitted from the automatic transmission 14 to a differential gear (differential gear) 16 via a propulsion shaft (propeller shaft) 15, and is transmitted from the differential gear 16 to a drive wheel 18 via a drive shaft (drive shaft) 17. ing. The automatic transmission 14 will be described using AMT as an example, but is not limited to AMT, and may be, for example, a torque converter type AT.

  The automatic transmission 14 has a plurality of shift stages (including a reverse shift stage) with different gear ratios, and when the manual shift mode is selected by a shift lever (not shown), the shift lever by the driver Based on these operations, the control device 20 performs upshift and downshift of the gear stage. Further, the automatic transmission 14 has a vehicle speed V detected by the vehicle speed sensor 21 and an accelerator opening Ao of the accelerator pedal 23 detected by the accelerator opening sensor 22 when the automatic shift mode is selected by the shift lever. Based on the above, the control device 20 performs upshift and downshift of the gear stage.

  The control device 20 performs shift control of the shift stage of the automatic transmission 14 and connection / disconnection control of the clutch 13, and is connected in communication with an engine control device that controls the engine 11 (not shown). The control device 20 has a shift map M1 for the normal mode and a shift map M2 for the eco mode that are used when the automatic transmission mode is selected by the shift lever. In the shift maps M1 and M2, an upshift line Lu and a downshift line Ld based on the vehicle speed V and the accelerator opening Ao are set for each shift stage.

  In contrast to the normal mode shift map M1, the eco mode shift map M2 is a region where the high opening degree side of the upshift line Lu is set to the low speed side, and the fuel consumption rate (SFC) is high due to the early upshift. This is a map that increases the chances of driving the engine 11 and improves fuel efficiency.

  The shift map M1 in the normal mode and the shift map M2 in the eco mode are configured to be switched by turning on and off the changeover switch 25 provided in the cab. For example, when the changeover switch 25 is turned on, the eco-mode shift map M2 is used, and when the changeover switch 25 is turned off, the normal mode shift map M1 is used.

The accelerator pedal 23 is a pedal that can be depressed even when the accelerator opening Ao exceeds fully open (100%). The accelerator opening sensor 22 detects the accelerator opening Ao and the fuel injection amount of the engine 11 or the like. Is configured by an electronically controlled type that is electronically controlled. In addition, although the accelerator pedal 23 of embodiment demonstrates the example of a suspension type pedal, you may comprise it with an organ type pedal. Further, in this accelerator pedal 23, the resistance to depression is gradually increased until the accelerator opening Ao exceeds fully opened and the kick down switch 24 is turned on, or the feeling of depression is made different when fully opened. At the same time, it is preferable that the sensation is further changed when the kick-down switch 24 is turned on beyond the fully open position. Thus, it is possible to notify the driver that the accelerator opening Ao is fully open, and further that when the accelerator opening Ao exceeds the full opening, the kick-down switch 24 is turned on.

  The accelerator pedal 23 is provided with a kick-down switch 24 in addition to an accelerator opening sensor 22 that detects an accelerator opening Ao. The kick-down switch 24 is an on / off switch that is turned off when the accelerator pedal 23 is depressed and the accelerator opening Ao does not exceed fully open, and is turned on when the accelerator opening Ao exceeds fully opened. It is configured.

  In this embodiment, an example is described in which the kickdown switch 24 is used to detect that the accelerator opening Ao exceeds fully open. However, instead of the kickdown switch 24, the accelerator opening whose setting has been changed is used. A degree sensor may be used. In the accelerator opening sensor instead of the kick down switch 24, the accelerator opening Ao is detected from a fully closed (0%) to a value exceeding the fully opened (100%) (for example, 110%), and the detected accelerator is detected. It is set to output fully closed at the opening Ao as fully closed, to output fully opened as a value less than fully opened (for example, 90%), and to output a value exceeding fully opened as fully opened. , 0% to 100% is replaced with a range of 0% to 90%, and 100% is set when 90% is exceeded. Further, when the accelerator opening sensor whose setting is changed instead of the kick down switch 24 is used, the setting of the control device 20 is also changed in the same manner as the change of the setting.

  When the accelerator pedal 23 is depressed beyond the full opening of the accelerator opening Ao and a kick down operation is performed to turn on the kick down switch 24, the control device 20 sets the selected gear position of the automatic transmission 14 one step. Control is performed to execute a downshift to shift to a gear stage with a high gear ratio.

  As described above, when the kick-down switch 24 provided on the accelerator pedal 23 configured to be able to be depressed even when fully opened is detected, it is detected that the kick-down operation has occurred. Downshift that accurately reflects the kickdown operation performed.

  In the control device of the prior art, when the kickdown operation is performed in a situation where the vehicle speed or the accelerator opening is in the vicinity of the upshift line, a so-called shift busy state occurs in which the upshift is performed immediately after the downshift. The fuel economy and drivability were getting worse.

  As a countermeasure against this, in the control device 20, when the dead zone R is provided in the shift maps M1 and M2, and the kick down switch 24 is turned on in the dead zone R, the control device 20 performs control to prohibit the downshift of the gear stage. When the kick down switch 24 is turned on at a lower vehicle speed than the range of the dead zone R, control is performed to perform a downshift of the gear position.

  When a kickdown operation occurs in the dead zone R, the shift stage is not downshifted, so it is possible to avoid an upshift immediately after the downshift and to suppress frequent shifts (shift busy) due to the kickdown operation. Thus, it is advantageous for improving fuel consumption and drivability.

  On the other hand, in the eco-mode shift map M2, by providing the dead zone R, the space between the downshift line Ld and the dead zone R is narrowed, and it is difficult to obtain acceleration by a kick down operation intended by the driver.

  Therefore, in the control device 20 of the automatic transmission 14 according to the present invention, the kick-down switch 24 is turned on in the dead zone R, and the currently selected shift map is executed before executing the control for prohibiting the downshift of the shift stage. Before selecting the shift map M1 in which the gap between the downshift line Ld1 and the dead band R is set wider than M2, and switching to the shift map M1, the control is performed to perform the downshift of the shift stage. The shift map M2 is configured to avoid the control for prohibiting the downshift of the shift speed by the dead zone R.

  FIG. 2 shows a part of the shift map M1 in the normal mode, and FIG. 3 shows a part of the shift map M2 in the eco mode. Since the basic configurations of the shift maps M1 and M2 are the same, the following description will be given by taking the normal mode shift map M1 shown in FIG. 2 as an example, and the eco mode shift map M2 shown in FIG. Differences from the map M1 will be described later.

  In the shift map M1, a plurality of downshift lines Ld1 and a plurality of upshift lines Lu2 based on the vehicle speed V and the accelerator opening Ao are set for each shift stage. For example, when the automatic transmission 14 has the first to sixth speeds, five downshift lines Ld1 and five upshift lines Lu2 are set in the shift map M1.

  The downshift line Ld1 is set to a shape in which the vehicle speed on the high opening side of the downshift line Ld1 is close to the low opening vehicle speed Vd1, in this embodiment, a linear shape parallel to the accelerator opening axis La. . The low opening vehicle speed Vd1 is the vehicle speed set to the fully open (0%) of the accelerator opening Ao, and the vehicle speed on the high opening side is the vehicle speed set to the fully open (100%) of the accelerator opening Ao. Yes, each is a vehicle speed determined in advance by experiments and tests.

  Thus, when the vehicle speed on the high opening side approaches the low opening vehicle speed Vd1, the vehicle speed V decelerates beyond the downshift line Ld, and the vehicle speed V is the low opening vehicle speed Vd1 and the high opening side vehicle speed. When the accelerator opening Ao reaches near full open, the gear G2 is downshifted to the gear G1 based on the downshift line Ld, otherwise the accelerator pedal 23 is opened to the accelerator pedal 23. Since the shift stage is downshifted only when a kickdown operation that is depressed beyond the fully open degree Ao occurs, that is, only when the kickdown switch 24 is turned on, the driver's intention The number of downshifts due to unintended kickdowns can be reduced by suppressing the occurrence of kickdown operations that are not performed, which is advantageous in improving fuel consumption.

  Further, since the shift stage of the automatic transmission 14 can be downshifted by a kickdown operation intended by the driver while traveling in the automatic shift mode, the shift map M1 prepared for a flat road can be used. On slopes, the kick-down operation can be used. As a result, it is possible to travel on the slope without using the shift map for the slope other than the shift map M1, and the control of the automatic transmission 14 can be prevented from being complicated.

  In the downshift line Ld, the high opening side vehicle speed that is the upper limit value of the vehicle speed V in the downshift line Ld is set to be lower than the low opening degree vehicle speed Vu1 that is the lower limit value of the vehicle speed V in the upshift line Lu. Is desirable. By setting in this way, it is possible to suppress a downshift of the gear stage contrary to the driver's intention between the vehicle speed on the high opening degree side and the vehicle speed Vu1 on the low opening degree.

  Further, as the vehicle speed on the high opening side becomes closer to the low opening vehicle speed Vd1, the downshift of the gear stage contrary to the driver's intention can be suppressed. Therefore, as in this embodiment, the accelerator opening Ao More preferably, the vehicle speed from fully closed (0%) to fully opened (100%) is made constant, that is, set to a linear shape parallel to the accelerator opening axis La in the shift map M1.

  By forming the downshift line Ld in a straight line in this manner, even if the accelerator pedal 23 is operated in the vicinity of the downshift line Ld and the accelerator operation is less than or equal to the fully open accelerator opening Ao, the downshift line Ld is reliably reduced by kickdown. Since the shift can be avoided, it is advantageous for suppressing the occurrence of kickdown not intended by the driver. In addition, the downshift line Ld can be set to a flat shape with respect to the low opening vehicle speed Vd1, and the high opening vehicle speed Vu2 of the upshift line Lu can be lowered to the lower vehicle speed side. Can be planned. This increases the chances of operating the engine 11 in a region where the fuel consumption rate (SFC) is high, which is advantageous for improving fuel consumption.

  Accordingly, the control device 20 determines, based on the downshift line Ld1, when the vehicle speed V decelerates from the right side to the left side of the shift map M1 beyond the downshift line Ld1, that is, the downshift line Ld1 starts from the right side. When the vehicle is crossed to the left, it is downshifted to a gear having a gear ratio that is one step higher than the currently selected gear, and in a range between the downshift line Ld and the low opening vehicle speed Vu1 on the upshift line Lu. Even if the vehicle speed V changes, the shift stage is not downshifted, and only when the kick down switch 24 is turned on, the shift stage is shifted down to a shift stage having a gear ratio higher than the currently selected shift stage. .

  The upshift line Lu1 is set so that the high opening vehicle speed Vu2 on the high opening side of the accelerator opening Ao is higher than the low opening vehicle speed Vu1 on the low opening side. When Ao is in the low opening portion, it substantially overlaps the line indicating the low opening vehicle speed Vu1 set based on the gear position, and as the opening degree increases, the vehicle speed V increases toward the higher speed side. It is set to a curved shape so as to be Vu2.

  Therefore, the control device 20 is based on the upshift line Lu1, when the vehicle speed V increases from the left to the right of the shift map M1 beyond the upshift line Lu1, and from above to below the shift map M1. When the accelerator opening Ao exceeds the upshift line Lu1 and returns to the closing direction, an upshift is performed to a gear having a gear ratio that is one step lower than the currently selected gear.

  The dead zone R is provided on the low vehicle speed side from the high opening vehicle speed Vu2 which is the vehicle speed when the accelerator opening Ao on the upshift line Lu1 is fully opened. The value of the vehicle speed width Δd of the dead zone R in the direction of the vehicle speed axis Lb is determined in advance by experiments and tests when the accelerator pedal 23 is depressed beyond the full opening of the accelerator opening Ao, and the kick down switch 24 is turned on. It is desirable to set a range where the upshift line Lu1 is exceeded and the upshift of the gear stage is not executed immediately after the downshift when the downshift of the gear stage is performed. It is more desirable to set the acceleration based on the assumption that it has been executed.

  In the eco-mode shift map M2 shown in FIG. 3, the high-opening vehicle speed Vu4 of the upshift line Lu2 is set on the lower speed side than the shift map M1 in the normal mode.

  Next, the speed change method of the automatic transmission 14 performed by the control device 20 will be described. Here, one of a plurality of shift stages of the automatic transmission 14 is G1, a shift stage having a gear ratio lower than that of the shift stage G1 is G2, and the downshift lines Ld1 and Ld2 are shifted from the shift stage G2. The downshift line to the stage G1 is used, and the upshift lines Lu1 and Lu2 are the upshift lines from the speed stage G1 to the speed stage G2. Further, the driving situation in the eco-mode shift map M2, that is, the depression operation of the accelerator pedal 23 is indicated by points A1 to A11.

When the shift stage G2 is selected and the accelerator pedal 23 is depressed from the point A1 to the point A2, the downshift line Ld2 is not crossed and the kick down switch 24 is turned off. The device 20 does not shift the gear stage G2 of the automatic transmission 14.

  When the shift stage G2 is selected and the accelerator pedal 23 is depressed from the point A1 to the point A3, it does not cross the downshift line Ld2, but the accelerator opening Ao exceeds fully open (100%). Since the kick down switch 24 is turned on outside the range of the dead zone R, the control device 20 downshifts the gear stage G2 of the automatic transmission 14 to the gear stage G1.

  When the gear stage G2 is selected and the vehicle speed V is decelerated from the point A4 to the point A5, the kick down switch 24 is turned off, but the control device 20 crosses the downshift line Ld2 so that the control device 20 The shift stage G2 of the automatic transmission 14 is downshifted to the shift stage G1.

  When the gear stage G1 is selected, the vehicle speed V accelerates from the point A6 to the point A7 and crosses the upshift line Lu2, so the control device 20 upshifts the gear stage G1 of the automatic transmission 14 to the gear stage G2. To do.

  When the shift stage G2 is selected and the accelerator pedal 23 is depressed from the point A8 to the point A9, the accelerator opening Ao exceeds the full open (100%), and the kick down switch 24 is turned on. Since the points A8 and A9 are within the range of the dead zone R, the control device 20 does not shift the gear stage G2 of the automatic transmission 14.

  At this time, the control device 20 switches from the shift map M2 to the shift map M1 before the downshift of the gear stage G2 of the automatic transmission 14 is prohibited. As shown in FIG. 2, when the accelerator pedal 23 is depressed from the point A8 to the point A9 in the shift map M1, the accelerator opening Ao is fully opened (100%) although it does not cross the downshift line Ld1. Since the kick-down switch 24 is turned on at a vehicle speed that exceeds the dead zone R and exceeds the range of the dead zone R, the control device 20 downshifts the gear stage G2 of the automatic transmission 14 to the gear stage G1.

  As described above, in the shifting method of the automatic transmission 14, when the eco-mode shift map M2 is selected during traveling in the automatic shift mode, the dead zone R in the vicinity of the upshift line Lu2 of the shift map M2. When a downshift of the gear position is prohibited due to a kick-down operation, the distance between the downshift line Ld1 and the dead zone R is more than that of the currently selected shift map M2 before the downshift of the gear position is prohibited. After switching to a widely set shift map M1, the gear position is downshifted. Thereby, prohibition of downshifting of the gear stage due to the dead zone R of the shift map M2 before switching is avoided.

  Therefore, according to the control device 20 and the speed change method of the automatic transmission 14 of the present invention, when the kick down switch 24 is turned on in the dead zone R of the eco-mode shift map M2, the shift stage is shifted down. Before the prohibition, the shift stage is downshifted after switching to the shift map M1, thereby avoiding the prohibition of the shift stage downshift due to the dead zone R of the shift map M2 before being switched. This makes it possible to achieve acceleration by kickdown operation intended by the driver while driving.

  In particular, the present invention provides a shift map M2 in which the space between the downshift line Ld2 and the dead zone R is set narrow, that is, an eco mode with better fuel efficiency than the high opening degree side of the upshift line Lu2 being set on the lower speed side. This is suitable when using the shift map M2, and usually when driving with good fuel efficiency, and when the driver desires acceleration, the acceleration can be realized, so the overall fuel efficiency is improved. As well as being able to suppress deterioration of drivability.

In the control device 20 of the automatic transmission 14, the accelerator opening Ao is set to a predetermined opening after the kick-down switch 24 is turned on while the changeover switch 25 is kept on. In the case of α1, it is desirable to perform control to select the shift map M2 that was selected before the kick-down switch 24 was turned on.

  The return opening α1 is preferably set to an opening at which it can be determined that the driver does not require acceleration, and more preferably set to a value of 60% or more and 80% or less of the accelerator opening.

  According to this configuration, the downshift of the gear stage by the kickdown operation is urgent, and the changeover switch 25 is kept on, that is, based on the eco-mode shift map M2 in which the driver consumes less fuel. Further, when traveling in the automatic shift mode is intended, the shift map M1 can be switched to the shift map M2 as intended by the driver, which is advantageous in improving fuel consumption.

DESCRIPTION OF SYMBOLS 10 Vehicle 14 Automatic transmission 20 Control apparatus 21 Vehicle speed sensor 22 Accelerator opening degree sensor 23 Accelerator pedal 24 Kick down switch 25 Changeover switch Ao Accelerator opening degree La Accelerator opening degree axis Lb Vehicle speed axis Ld1, Ld2 Downshift line Lu1, Lu2 Upshift Lines M1, M2 Shift map V Vehicle speed Vd1 Low opening vehicle speed Vu2 High opening vehicle speed R Dead zone

Claims (5)

An automatic transmission having a plurality of shift maps in which an upshift line and a downshift line based on a vehicle speed and an accelerator opening of an accelerator pedal are set for each shift stage, and using the selected shift map at the time of automatic shift In addition to performing control to perform upshift and downshift of
Connected to a kick-down switch provided on an accelerator pedal configured to be able to be depressed even when the accelerator opening exceeds the full opening, a kick-down operation is performed in which the accelerator pedal is depressed beyond the full opening of the accelerator opening. When the kick down switch is turned on, a control device for an automatic transmission that performs control to execute a downshift of the shift stage,
A dead zone having a preset vehicle speed width in the vehicle speed axis direction is provided from the high opening vehicle speed, which is the vehicle speed when the accelerator opening is fully opened in the upshift line, to the low vehicle speed side,
The kick down switch is turned on in the dead zone, and before the control for prohibiting the downshift of the shift stage is executed, the gap between the down shift line and the dead zone is set wider than the currently selected shift map. After selecting the shift map and switching to the shift map, control is performed to perform the downshift of the shift stage, and the control to prohibit the downshift of the shift stage due to the dead zone of the shift map before the switch is avoided. A control device for an automatic transmission, characterized in that it is configured.   Control that selects the shift map selected before the kick-down switch is turned on when the accelerator opening is a predetermined return opening degree after the kick-down switch is turned on 2. The control device for an automatic transmission according to claim 1, wherein   The control apparatus for an automatic transmission according to claim 2, wherein the return opening is set to a value not less than 60% and not more than 80% of the accelerator opening.   The control apparatus for an automatic transmission according to any one of claims 1 to 3, wherein the downshift line is set in a linear shape parallel to an accelerator opening axis in the shift map. During automatic gear shifting, the upshift line and downshift line based on the vehicle speed and accelerator pedal opening are switched between multiple shift maps set for each gear stage to upshift and downshift the automatic transmission gear stage. In a shifting method of a shifting automatic transmission,
In the dead zone provided on the low shift speed side from the high opening vehicle speed that is the vehicle speed when the accelerator opening is fully opened in the upshift line, a kick down operation that is stepped on the accelerator pedal beyond the fully opening of the accelerator opening is performed. If this happens and you want to prohibit downshifting
Before prohibiting the downshift of the shift stage, after switching to a shift map that is set wider between the downshift line and the dead zone than the currently selected shift map, downshift the shift stage, A shift method for an automatic transmission characterized by avoiding prohibition of downshifting of a shift stage due to the dead zone of a shift map before switching.

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