JP2004060734A - Transmission control device for automatic transmission - Google Patents

Abstract

An object of the present invention is to reduce as much as possible uncomfortable feeling when executing a process of forcibly increasing a gear ratio due to a decrease in vehicle speed during a manual shift mode.
A shift mode of an automatic transmission is switched between an automatic shift mode and a manual shift mode based on an operation of a shift lever. During the selection of the manual transmission mode, the gear position of the automatic transmission 11 is switched to and held by the operation of the shift switches 36 and 37. The electronic control unit 40 monitors the vehicle speed, and forcibly executes a downshift when the vehicle speed falls below an allowable speed range in the current gear position. At this time, the electronic control unit 40 also monitors that the internal combustion engine 10 switches from the driven state to the driven state, and executes the downshift in accordance with the switching.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic transmission mode in which a gear stage of an automatic transmission mounted on a vehicle internal combustion engine is automatically changed to a gear ratio set based on a vehicle running state and an engine operating state; The present invention relates to a shift control device for an automatic transmission that selectively switches between a shift mode and a manual shift mode in which a ratio is maintained at a shift ratio selected through a selection mechanism.
[0002]
[Prior art]
In general, in an automatic transmission mounted on an internal combustion engine for a vehicle, the most appropriate gear position according to a vehicle running state such as a vehicle speed and an engine operating state such as an accelerator opening is set through a shift control device. Selected. Then, the gear position of the automatic transmission is automatically switched based on a shift command output from the control device. Further, even in the shift control device that performs such an automatic shift mode, the driver can change the gear shift pattern of the device by a plurality of modes (for example, a mode that emphasizes acceleration and a mode that emphasizes fuel efficiency). Some of them can be selected from among them. As a result, the driver's will can be reflected to some extent when the gear is switched. However, this is also merely for switching the shift pattern, and the selection of the gear position itself is basically left to the shift control device.
[0003]
On the other hand, in recent years, as shown in, for example, Japanese Patent Application Laid-Open No. 8-193656, in addition to the automatic shift mode, switching to a so-called manual shift mode in which the shift pattern of such an automatic transmission is determined by the driver's will is described. Possible transmission control devices have also been proposed.
[0004]
In this manual shift mode, an arbitrary gear position is selected by the driver through a selection mechanism such as a shift lever or a shift switch provided on a steering wheel. Unless the gear position is selected again through such a selection mechanism, the gear position of the automatic transmission is basically controlled so as to be maintained at the selected gear position. As described above, by enabling the shift mode of the automatic transmission to be switched to the manual shift mode, the operational feeling of a vehicle including the manual transmission can be obtained in a pseudo manner as needed while the automatic transmission is mounted. become. As a result, the driver's will can be reflected to the maximum in the gear shifting operation of the vehicle.
[0005]
However, even when such a manual shift mode is selected, if a predetermined condition is satisfied, the selection of the gear by the driver is canceled, and the gear of the automatic transmission is forcibly forced through the shift control device. May be switched. For example, in a case where the vehicle shifts to a deceleration state when a braking operation is performed when the vehicle stops or turns, if the driver does not switch gears at all, the gear position of the automatic transmission becomes the fourth gear or the like. Therefore, the vehicle speed is reduced while being held in the low gear ratio. In such a case, there is a concern about a rise in the temperature of the automatic transmission due to the input of an excessive load, and a decrease in the running performance when shifting from such a deceleration state to an acceleration state, that is, a decrease in acceleration performance.
[0006]
Therefore, conventionally, an allowable speed is set in advance according to the currently selected gear position, and when the vehicle speed falls below this allowable speed, the manual shift mode is canceled to forcefully increase the speed ratio. A downshift is performed.
[0007]
[Problems to be solved by the invention]
As described above, by executing the downshift when the vehicle speed falls below the allowable speed, it is possible to suppress a rise in the temperature of the automatic transmission and a decrease in the traveling performance during subsequent acceleration. become.
[0008]
However, if such a downshift is executed simply by considering only a decrease in the vehicle speed, the following inconveniences cannot be ignored. Even though the driver has selected the manual shift mode and has not issued a shift request, the gear stage will be changed regardless of his or her intention. On the other hand, I feel great discomfort.
[0009]
It should be noted that in a continuously variable transmission (so-called "CVT") in which the gear ratio is continuously changed, a manual transmission mode similar to the above-described gear-type automatic transmission can be selected in addition to the automatic transmission mode. There is something. That is, when the manual transmission mode is selected as the transmission mode of such a continuously variable transmission, the transmission ratio can be selected only at a specific stage (for example, four stages), and the transmission control is substantially the same as that of the gear type automatic transmission. Is performed. For this reason, even with such a continuously variable transmission, the above-mentioned inconveniences associated with the shift shock in the manual shift mode are substantially common to those of the gear-type automatic transmission.
[0010]
SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional situation, and an object of the present invention is to provide a shift control device for an automatic transmission capable of switching between an automatic shift mode and a manual shift mode. Accordingly, it is desirable to reduce a sense of incongruity as much as possible when the process of forcibly increasing the speed ratio accompanying the execution is performed.
[0011]
[Means for Solving the Problems]
Hereinafter, means for solving the above-described problems and the effects thereof will be described.
In the invention according to claim 1, an automatic transmission mode in which a transmission ratio of an automatic transmission mounted on the internal combustion engine for a vehicle is automatically changed to a transmission ratio set based on a vehicle running state and an engine operating state; The speed ratio of the automatic transmission can be selectively switched to a manual speed mode in which the speed ratio is selected through a selection mechanism, and the vehicle speed is set based on the held speed ratio in the manual speed change mode. A shift control device for an automatic transmission for a vehicle, which releases the holding of the gear ratio and increases the gear ratio when the vehicle is in a low speed region equal to or lower than a first predetermined speed. Monitoring means for monitoring switching from the driven state to the driving state for driving the vehicle, and switching the internal combustion engine from the driven state to the driving state based on the monitoring result of the monitoring means. Waru fit in so that and a shift timing control means for executing the increasing process of the gear ratio.
[0012]
Shift shock of the automatic transmission occurs due to a sudden change in drive torque transmitted from the output shaft of the internal combustion engine to the vehicle drive system. In particular, the process of increasing the speed ratio at a somewhat high vehicle speed increases the driven force of the vehicle, and generally generates a large shock. Therefore, when the gear ratio increasing process is performed by the gear change control device while the driver is not making a gear change request in the manual gear change mode, the driver feels a great sense of discomfort. On the other hand, when the engine output increases due to the driver's accelerator operation or the like, the internal combustion engine changes from a driven state driven by the vehicle to a driven state driving the engine.
[0013]
Focusing on this point, according to the first aspect of the present invention, the engine output increases as the driver operates the accelerator and the like, and the speed ratio increases as the internal combustion engine changes from the driven state to the driven state. The processing is executed. For this reason, the amount of increase in the driven force due to such speed ratio increase processing is suppressed, and the sense of discomfort associated with the speed change shock is reduced. Therefore, in the process of increasing the gear ratio, for example, forcibly performing a downshift accompanying a decrease in the vehicle speed during the selection of the manual shift mode, it is possible to minimize the discomfort that accompanies the process. The "gear ratio" means the rotation speed of the input shaft and the output shaft of the automatic transmission (input shaft rotation speed / output shaft rotation speed), and the "increase process" means that the gear speed is reduced. For example, this means a process of changing the gear ratio set in stages to a larger gear ratio.
[0014]
According to a second aspect of the present invention, in the shift control device for an automatic transmission according to the first aspect, the shift timing control unit is configured to execute a speed lower than a second predetermined speed lower than the first predetermined speed in the low speed range. When the vehicle speed shifts to the range, the speed ratio increasing process is forcibly executed regardless of whether the internal combustion engine is driven or driven.
[0015]
According to this configuration, the temperature rise of the automatic transmission and the subsequent acceleration when the vehicle stops or when the vehicle speed greatly decreases during a turn while minimizing the sense of discomfort associated with the gear ratio increase process are minimized. It is also possible to suppress a decrease in the acceleration performance when the state is shifted.
[0016]
Further, the switching from the driven state to the driving state as described above can be appropriately monitored based on the engine load, as in the third aspect of the present invention.
[0017]
Further, since such an engine load has a high correlation with the accelerator operation amount of the internal combustion engine, the accelerator operation amount of the internal combustion engine is used as a substitute value of the engine load, and based on the accelerator operation amount. A configuration in which switching from the driven state to the driving state is monitored can be adopted. In addition, as the state quantity having a high correlation with the engine load, for example, an intake air amount or an intake pressure can be adopted in addition to the accelerator operation amount.
[0018]
In monitoring the switching of the internal combustion engine from the driven state to the driving state based on the engine load such as the accelerator operation amount, the third or fourth aspect of the present invention provides the present invention. In the shift control device for an automatic transmission according to the first aspect, the monitoring means may be configured to control the internal combustion engine to operate in the driven state based on a change in the engine load from a state lower than a predetermined determination value to a value equal to or higher than the predetermined determination value in the low speed range. To determine that the driving state has been switched to the driving state.
[0019]
According to this configuration, the switching between the driven and driven states can be relatively easily determined. As for the determination value, an average value of the engine load when the internal combustion engine switches from the driven state to the driven state is obtained in advance based on an experiment or the like, and can be set as the same determination value. In addition, it is desirable to individually or comprehensively consider various parameters that affect the switching, such as the inertia of the vehicle, the driving resistance of the vehicle drive system, and the running resistance such as air resistance. Further, when these various parameters change according to the running state of the vehicle, a method of variably setting the determination value according to the running state is also effective in increasing the reliability of the switching determination. It is.
[0020]
According to a sixth aspect of the present invention, in the shift control device for an automatic transmission according to the fifth aspect, the monitoring means sets the predetermined determination value to be larger as the vehicle speed is higher.
[0021]
Generally, as the vehicle speed increases, traveling resistance such as air resistance acting on the vehicle increases. Therefore, when the engine load of the driven internal combustion engine is increased, the internal combustion engine switches from a higher engine load stage to a driven state as the vehicle speed increases.
[0022]
In the invention according to claim 6, when monitoring that the internal combustion engine switches from the driven state to the driven state, the determination value for determining the switching is set to be larger as the vehicle speed is higher. Therefore, the determination value can be appropriately set according to the running resistance that changes according to the air resistance and the like, and the reliability of the switching determination can be improved.
[0023]
Further, such running resistance changes in addition to the air resistance changing according to the speed of the vehicle as described above, and also changes depending on the state of the running path, that is, whether the running path is an uphill road or a downhill road. That is, the running resistance when the vehicle runs at a constant speed increases when the vehicle runs on an uphill road, and decreases when the vehicle runs on a downhill road. Therefore, on a downhill road, the internal combustion engine is driven under a smaller engine load, while on an uphill road, the internal combustion engine does not shift to the driven state until the engine load becomes higher.
[0024]
Focusing on this point, in the invention according to claim 7, the shift control device for an automatic transmission according to claim 5 or 6, further comprising estimating means for estimating a gradient of a traveling path of the vehicle, The monitoring means sets the predetermined determination value to a smaller value when the travel path of the vehicle is estimated to be an uphill road by the estimation means than when the travel path is estimated to be a downhill road. ing. Accordingly, the determination value can be appropriately set according to the traveling resistance that changes depending on the state of the traveling road, and the reliability of the switching determination can be further improved.
[0025]
In addition, the traveling resistance increases as the gradient (uphill gradient) increases on an uphill road and decreases as the gradient (downhill gradient) decreases on a downhill road.
Focusing on this point, the invention according to claim 8 is the shift control device for an automatic transmission according to claim 7, wherein the monitoring means is configured such that, when the traveling path of the vehicle is an uphill road, the gradient thereof increases as the gradient increases. While the predetermined determination value is set to a large value, when the traveling path of the vehicle is a downhill road, the predetermined determination value is set to a smaller value as the gradient thereof is larger.
[0026]
According to this configuration, the determination value can be appropriately set according to the degree of the gradient of the traveling road, and the reliability of the switching determination can be further improved.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0028]
FIG. 1 is a schematic configuration diagram illustrating a configuration of an automatic transmission that is a control target of a transmission control device according to the present embodiment, and an internal combustion engine in which the automatic transmission is mounted.
As shown in FIG. 1, an automatic transmission 11 including a torque converter 14 and a transmission main body 16 is connected to an output shaft 12 of the internal combustion engine 10. The torque generated as the output shaft 12 of the internal combustion engine 10 rotates is subjected to speed / torque conversion by the automatic transmission 11 at a predetermined speed ratio, and then the vehicle is driven from the output shaft 18 of the automatic transmission 11. It is output as a torque for use. The driving torque output in this manner is finally transmitted to driving wheels (not shown) of the vehicle via a differential gear (not shown). The “speed ratio” is the ratio of the rotational speeds of the input shaft of the automatic transmission 11, that is, the output shaft 12 of the internal combustion engine 10 and the output shaft 18 of the automatic transmission 11 (the rotational speed of the output shaft 12). / Rotational speed of output shaft 18).
[0029]
The shift operation of the automatic transmission 11 is controlled by the electronic control unit 40. Specifically, by controlling a hydraulic drive mechanism (not shown) provided inside the automatic transmission 11 through the electronic control device 40, the gear ratio, here, the gear stage is “first speed”, It can be selectively switched between "2nd speed", "3rd speed", "4th speed", and "reverse".
[0030]
The shift control of the automatic transmission 11 by the electronic control unit 40 is roughly divided into automatic shift control and manual shift control. In the automatic shift control, the shift mode of the automatic transmission 11 is set to the automatic shift mode, and the gear is switched based on the vehicle running state and the engine operating state. On the other hand, in the manual shift control, the shift mode of the automatic transmission 11 is set to the manual shift mode, and the gear is switched to the gear selected by the driver.
[0031]
The electronic control unit 40 temporarily stores, in addition to a control program for executing each of these controls, calculation results of these controls, or a calculation map or the like necessary for executing these controls. It has.
[0032]
The internal combustion engine 10 and the vehicle are provided with various sensors for detecting an engine operating state and a vehicle running state in order to execute a shift control of the automatic transmission 11 by such a transmission. For example, a rotation speed sensor 31 that detects the rotation speed of the output shaft 12, that is, the engine rotation speed, is provided near the output shaft 12 of the internal combustion engine 10. An accelerator sensor 32 for detecting the operation amount (accelerator opening) is provided near the accelerator pedal 24. In the vicinity of the output shaft 18 of the automatic transmission 11, a vehicle speed sensor 33 for detecting the running speed (vehicle speed) of the vehicle from its rotation speed is provided. Further, an intake air amount sensor 34 is provided upstream of the throttle valve 21 in the intake passage 13 of the internal combustion engine 10.
[0033]
In addition to these sensors, a shift position sensor 35 for detecting a shift position is provided near a shift lever 28 provided in a vehicle compartment (not shown). The shift position of the shift lever 28 is selectively switched by the driver to any one of “L”, “2”, “N”, “D”, “R”, and “M”.
[0034]
The steering wheel 26 is provided with a downshift switch 36 and an upshift switch 37 whose operation is effective only when the shift lever 28 is at the shift position “M”. The downshift switch 36 is used to increase the gear ratio of the automatic transmission 11. Each time the downshift switch 36 is operated, a downshift is executed through the shift control of the electronic control unit 40, and the gear position of the automatic transmission 11 is changed. The gear can be switched to one lower than the current gear. On the other hand, the upshift switch 37 is for lowering the gear ratio of the automatic transmission 11, and each time the switch is operated, a downshift is executed through the shift control of the electronic control unit 40, and the automatic transmission The eleven gears are switched to a gear one higher than the current state.
[0035]
When the shift position selected through the operation of the shift lever 28 is at a position other than “M”, that is, at any of the positions “L”, “2”, “N”, “R”, and “D”, Automatic shift control is performed by the control device 40.
[0036]
In this automatic transmission control, basically, the gear position of the automatic transmission 11 is automatically selected based on the shift position of the shift lever 28, the vehicle speed, and the accelerator opening, and the selected automatic transmission The gear of the machine 11 is switched. For example, when the shift position of the shift lever 28 is “L”, the gear position of the automatic transmission 11 is fixed to “1st speed”. When the shift position is “2”, the gear position of the automatic transmission 11 is selectively switched between “first speed” and “second speed”. Further, when the shift position of the shift lever 28 is at “D”, the gear position of the automatic transmission 11 is selectively switched between “1st speed” to “4th speed”. When the shift position is “N”, the output of the driving torque from the automatic transmission 11 (specifically, the output shaft 18 thereof) is stopped, and the automatic transmission 11 enters a so-called neutral state. In addition, when the shift position of the shift lever 28 is “R”, the gear position of the automatic transmission 11 is fixed to “reverse”.
[0037]
When the shift position of the shift lever 28 is “2” or “D”, the electronic control unit 40 determines the gear most suitable for the current vehicle running state and the engine operating state based on the vehicle speed and the accelerator opening. And the gear of the automatic transmission 11 is switched to the selected gear. In order to select such gears, the memory 42 of the electronic control unit 40 stores in the memory 42 the relationship between the vehicle speed and the accelerator opening and the corresponding gears, which are separately defined for vehicle acceleration and deceleration. In the point map, each shift position is stored corresponding to “2” and “D”.
[0038]
When the shift position of the shift lever 28 is “M” with respect to the automatic shift control, the electronic control unit 40 executes the manual shift control.
In the manual shift control, the gear of the automatic transmission 11 is switched to the gear selected by the driver through the operation of the downshift switch 36 and the upshift switch 37. Therefore, unless the driver operates the shift switches 36 and 37, the gear position of the automatic transmission 11 is basically maintained at the currently selected gear position.
[0039]
However, when the vehicle speed decreases due to a braking operation performed when the vehicle stops or turns, if the gear stage of the automatic transmission 11 is held at a low gear ratio such as the fourth speed, As described above, there is a concern that the temperature of the automatic transmission will increase due to the input of an excessive load, and that the acceleration performance will decrease thereafter.
[0040]
Therefore, in the present embodiment, the allowable speed is set in advance according to the currently selected gear position, and when the vehicle speed falls below the allowable speed, the manual shift mode is released to forcibly downshift. I am trying to run. Further, when such a downshift is performed, it is monitored whether the internal combustion engine 10 is in a driven state or a driven state, and the execution timing of the downshift is set based on the monitoring result, so that the shift shock is performed. Therefore, the driver's discomfort due to the vehicle is reduced as much as possible.
[0041]
Hereinafter, in such manual shift control, a procedure for monitoring the driven / driven state of the internal combustion engine 10 (drive state change determination processing) and a procedure for setting the execution timing of the downshift based on the monitoring result. The procedure (downshift execution timing setting processing) will be described with reference to FIGS.
[0042]
FIG. 2 is a flowchart illustrating a processing procedure of the driving state change determination processing. A series of processing shown in this flowchart is periodically executed by the electronic control device 40 at a predetermined interrupt cycle. Note that this series of processing is executed on the condition that the manual transmission mode is selected as the transmission mode of the automatic transmission 11, in other words, that the shift position of the shift lever 28 is "M".
[0043]
In this series of processing, first, it is determined whether or not the gear position of the automatic transmission 11 selected through the operation of each of the shift switches 36 and 37 is "first speed" (step S200). Here, if the gear position of the automatic transmission 11 is other than "1st speed", that is, any of "2nd speed" to "4th speed" (step S200: NO), the downshift map corresponding to that gear position Is selected (step S205). The downshift map is prepared for each of the second to fourth speeds of the automatic transmission 11 and stored in the memory 42 of the electronic control unit 40.
[0044]
FIG. 3 shows an example of a map in which the gear position is set to “fourth speed” among these maps. As shown in the figure, in this map, the area defined by the vehicle speed V and the accelerator opening ACCP is the first predetermined speed V1 and the second predetermined speed V2 related to the vehicle speed V, and the determination regarding the accelerator opening ACCP. The area is divided into four areas such as an area A, an area B, an area C, and an area D by the value ACCP1. It should be noted that the "third speed" and "second speed" maps also differ only in the manner of setting these areas, and have the same basic configuration.
[0045]
Here, the second predetermined speed V2 is extremely lower than the speed at which the vehicle speed V matches the currently selected gear position, and the temperature of the automatic transmission 11 increases due to the application of an excessive load. This is a value for determining that the vehicle is in a state where the decrease in acceleration performance cannot be ignored. That is, when the vehicle speed V is lower than the second predetermined speed V2, the vehicle speed V decreases to such an extent that the heat generation and the decrease in acceleration performance of the automatic transmission 11 cannot be ignored anymore. (Area D). Therefore, in this case, the downshift is forcibly executed regardless of the magnitude of the accelerator opening ACCP.
[0046]
On the other hand, the first predetermined speed V1 is a value for determining whether or not the vehicle speed V is in a speed range corresponding to the gear position of the automatic transmission 11. That is, when the vehicle speed V is equal to or higher than the first predetermined speed V1, it is determined that the vehicle speed V is in a speed range corresponding to the gear position of the automatic transmission 11 (region C). Therefore, in this case, the forced downshift as described above is not performed.
[0047]
Further, when the vehicle speed V is in a speed range (V2 <V <V1) sandwiched between the predetermined speeds V1 and V2, there is a concern that the temperature rise of the automatic transmission 11 and the decrease in the acceleration performance may occur. However, it is determined that the degree is low (areas A and B). Therefore, in this case, by appropriately controlling the execution timing of the downshift through the comparison between the accelerator opening ACCP and the appropriate determination value ACCP1 through the processes of steps S210 to S250, the driver's response to the shift shock is reduced. I try to reduce the discomfort as much as possible.
[0048]
That is, in these processes, first, the vehicle speed V is compared with the first predetermined speed V1 (step S210). If the vehicle speed V is equal to or lower than the first predetermined speed V1 (step S210: NO), the vehicle speed V is further compared with the second predetermined speed V2 (step S220).
[0049]
If a negative determination is made in each of steps S210 and S220 (step S210: NO, step S220: NO), the current accelerator opening ACCP is then compared with a predetermined determination value ACCP1. .
[0050]
Here, the determination value ACCP1 is a value for determining whether the internal combustion engine 10 is in a driven state or a driven state. The determination value ACCP1 is an average value of the accelerator opening ACCP when the internal combustion engine 10 switches from the driven state to the driven state, and is obtained in advance based on experiments and the like.
[0051]
If the accelerator opening ACCP is smaller than the determination value ACCP1 in this determination processing, it is determined that the internal combustion engine 10 is in the driven state (area A), and the driven state flag XDWNRDY is set to “ON” ( Step S260). Then, this series of processing is temporarily ended.
[0052]
On the other hand, when accelerator opening ACCP is equal to or greater than determination value ACCP1 (step S230: NO), it is next determined whether driven state flag XDWNRDY is set to "ON" (step S240). That is, here, it is determined whether or not the engine operating state and the vehicle running state have just shifted from the area A to the area B shown in FIG. 3, in other words, at the timing when the internal combustion engine 10 switches from the driven state to the driven state. It is determined whether there is.
[0053]
If it is determined that the driven state flag XDWNRDY is set to "ON" (step S240: YES), it may be determined that the timing at which the internal combustion engine 10 switches from the driven state to the driven state. it can. Therefore, the downshift execution flag XDWNEXE is set to “ON” to execute the downshift in accordance with this (step S250). Then, this series of processing is temporarily ended.
[0054]
On the other hand, when the driven state flag XDWNRDY is set to “OFF” (step S240: NO), it is determined that the engine operating state and the vehicle running state are maintained in the area B shown in FIG. You. Therefore, in this case, the “ON” operation of the downshift execution flag XDWNEXE is not performed, and this series of processing is temporarily ended.
[0055]
On the other hand, when it is determined in the previous step S210 that the vehicle speed V is higher than the first predetermined speed V1 (step S210: YES), the engine operating state and the vehicle running state are changed. 3 is in the area C shown in FIG. As described above, in this case, the vehicle speed V is in an appropriate speed range for the currently selected gear of the automatic transmission 11, and the temperature of the automatic transmission 11 increases and the acceleration performance decreases. There is no need to consider such things. Therefore, there is no need to perform a downshift. Therefore, in this case, both the downshift execution flag XDWNEXE and the driven state flag XDWNRDY are set to “OFF” (steps S270 and S280). Similarly, when it is determined in step S200 that the gear position of the automatic transmission 11 is set to "1st speed" (step S200: YES), the flags XDWNEXE and XDWNRDY are similarly set. It is set to “OFF”. After the "OFF" operation is performed on these flags XDWNEXE and XDWNRDY in this manner, this series of processing is temporarily terminated.
[0056]
On the other hand, if the vehicle speed V is lower than the second predetermined speed V2 in the previous step S220 (step S220: YES), the engine operating state and the vehicle running state are in the area D in FIG. As described above, in this case, the vehicle speed V greatly decreases in the speed range corresponding to the gear stage of the currently-selected automatic transmission 11, and the temperature of the automatic transmission 11 increases and the vehicle speed V increases after that. It is in a situation where the deterioration of the acceleration performance when shifting to the state cannot be avoided. Therefore, in this case, the downshift execution flag XDWNEXE is set to "ON" to forcibly execute the downshift regardless of the magnitude of the accelerator opening ACCP, in other words, regardless of the driven / driven state of the internal combustion engine 10. Is performed (step S250).
[0057]
Through the series of processes described above, the engine operating state and the vehicle running state are monitored. Then, when one of the following conditions (1) and (2) is satisfied, the downshift execution flag XDWNEXE is set to “ON”, and the downshift is executed.
[0058]
(1) When the vehicle speed V is in a speed range that satisfies (V2 ≦ V ≦ V1) and the accelerator opening ACCP switches from a state that satisfies (ACCP <ACCP1) to a state that satisfies (ACCP ≧ ACCP1).
(2) When the vehicle speed V is in a speed range satisfying (V <V2)
Next, the processing procedure of the downshift execution timing setting processing will be described with reference to the flowchart shown in FIG. A series of processing shown in this flowchart is periodically executed by the electronic control device 40 at a predetermined interrupt cycle.
[0059]
In this series of processing, first, it is determined whether or not the current shift mode is set to the manual shift mode (step S100). Here, when the automatic shift mode is selected, that is, when the shift position of the shift lever 28 is a shift position other than "M" (step S100: NO), this series of processing is temporarily ended. In this case, the electronic control unit 40 selects a gear position most suitable for the current shift position, the vehicle running state, and the engine operating state by a process different from the present process, and the gear of the automatic transmission 11 is selected. The gear is switched to this selected gear.
[0060]
On the other hand, if the shift position of shift lever 28 is at "M" (step S100: YES), it is then determined whether or not downshift execution flag XDWNEXE is set to "ON" (step S110). .
[0061]
Here, when the downshift execution flag XDWNEXE is “OFF” (step S110: NO), it is not necessary to execute the downshift, or the timing is not appropriate for executing the downshift. This series of processing is temporarily ended.
[0062]
On the other hand, when the downshift execution flag XDWNEXE is “ON” (step S110: YES), the downshift is executed (step S120). That is, when the currently-selected gear of the automatic transmission 11 is, for example, “fourth speed”, the speed is changed to “third speed”. Similarly, when the gear position of the automatic transmission 11 is, for example, “third speed”, the speed is switched to “second speed”, and when the gear speed is “second speed”, the speed is switched to “first speed”.
[0063]
After the downshift is performed in this manner, both the downshift execution flag XDWNEXE and the driven state flag XDWNRDY are set to “OFF” (steps S130 and S140). After the "OFF" operation of each of the flags XDWNEXE and XDWNRDY is performed, the series of processing is temporarily terminated.
[0064]
Hereinafter, an example of a control mode based on the drive state change determination processing and the downshift execution timing setting processing will be described with reference to FIG.
In FIG. 3, for example, the solid line P1 indicates that the accelerator pedal 24 is gradually depressed when the vehicle turns and the vehicle shifts to a deceleration state, and then the accelerator pedal 24 is depressed again to shift the vehicle to an acceleration state. In such a case, changes in the vehicle speed V and the accelerator opening ACCP are shown. In this case, the vehicle running state and the engine operating state shift from the area C to the area B and the area A, and finally shift from the area A to the area B, as indicated by the solid line P1. Then, when shifting from the area A to the area B, the downshift execution flag XDWNEXE is set to “ON”, and the downshift is executed.
[0065]
In FIG. 3, the dashed line P2 indicates, for example, a case where the vehicle travels on an uphill, the vehicle speed V gradually decreases, and then the accelerator pedal 24 is depressed and the vehicle shifts to an acceleration state. The transitions of the vehicle speed V and the accelerator opening ACCP are shown. In this case, the vehicle running state and the engine operating state shift from the area C shown in the figure to the area B, and finally shift to the area A. Also in this case, similarly to the example shown by the solid line P1, the downshift execution flag XDWNEXE is set to "ON" when the area A shifts from the area A, and the downshift is executed.
[0066]
Therefore, in these two examples, the downshift is executed in accordance with the switching of the internal combustion engine 10 from the driven state to the driven state, and the gear position of the automatic transmission 11 changes from “fourth speed” to “third speed”. You will be able to switch.
[0067]
On the other hand, in FIG. 3, a two-dot chain line P3 indicates, for example, changes in the vehicle speed V and the accelerator opening ACCP in the case where the accelerator pedal 24 is released and the braking operation is performed to stop the vehicle. Is shown. In this case, the vehicle running state and the engine operating state shift from the area C to the area B and then to the area A, and finally shift to the area D, as indicated by the two-dot chain line P3. In this case, the downshift execution flag XDWNEXE is set to “ON” when shifting to the area D, and the downshift is performed.
[0068]
Therefore, in this example, regardless of whether the internal combustion engine 10 is driven or driven, the vehicle running state and the engine operating state shift to the region D, in other words, the vehicle speed V becomes lower than the second predetermined speed V2. At this point, the downshift is forcibly executed, and the gear position of the automatic transmission 11 can be switched from "4th speed" to "3rd speed".
[0069]
Incidentally, when the downshift is executed and the gear position of the automatic transmission 11 is switched from “fourth speed” to “third speed” as in each of these examples, in step S205 shown in the flowchart of FIG. The map corresponding to the subsequent gear position, that is, "3rd speed" is selected. Then, the above-described processing is performed again based on the map. Therefore, for example, in the example shown by the two-dot chain line P3, even if the driver does not operate the downshift switch 36, the gear position of the automatic transmission 11 changes from “4th speed” → “3rd speed” → “2nd speed”. The speed is switched in the order of “speed” → “first speed”.
[0070]
According to the embodiment described above, the following operational effects can be obtained.
In the present embodiment, the internal combustion engine 10 monitors the switching from the driven state to the driving state through the previous driving state change determination processing, executes a downshift in accordance with the switching, and adjusts the gear ratio of the automatic transmission 11. I try to increase it. Normally, when the internal combustion engine 10 is switched from the driven state to the driven state, the driver intends to increase the engine output, such as depressing the accelerator pedal 24, and eventually accelerate the vehicle. For this reason, even if a shift shock occurs due to the execution of the downshift, the sense of incongruity due to the shift shock is small. Therefore, when performing the downshift due to the decrease in the vehicle speed during the selection of the manual shift mode, the uncomfortable feeling accompanying the downshift can be reduced as much as possible.
[0071]
Further, when the vehicle running state and the engine operating state shift to the region D shown in FIG. 3, in other words, the vehicle speed V falls within the speed range of the second predetermined speed V2 or lower, which is lower than the first predetermined speed V1. Upon shifting, the downshift is forcibly executed regardless of the driven / driven state of the internal combustion engine 10. Therefore, in the case where the vehicle stops or the vehicle speed V greatly decreases when turning, the temperature of the automatic transmission 11 is increased and the decrease in the acceleration performance when the vehicle is shifted to the acceleration state is also suppressed. Will be able to
[0072]
Also, when detecting the timing at which the internal combustion engine 10 switches from the driven state to the driven state, it is monitored that the accelerator opening degree ACCP becomes greater than or equal to the determination value ACCP1 from a state less than the determination value ACCP1. I have to. Therefore, the switching of the internal combustion engine 10 from the driven state to the driven state can be easily determined based on the monitoring result of the accelerator opening ACCP.
[0073]
[Second embodiment]
Next, a second embodiment of the present embodiment will be described focusing on differences from the first embodiment.
[0074]
In the first embodiment, the determination value ACCP1 relating to the accelerator opening ACCP for determining whether the internal combustion engine 10 is in the driven state or the driving state is set to a constant value regardless of the vehicle speed V. I am trying to do it.
[0075]
However, in general, as the vehicle speed V increases, traveling resistance such as air resistance acting on the vehicle increases. Therefore, when the engine load is increased by increasing the accelerator opening ACCP of the internal combustion engine 10 in the driven state, the higher the vehicle speed V, the larger the internal load of the internal combustion engine 10 in the stage of the engine load, in other words. For example, the driving state shifts from a stage where the accelerator opening ACCP is larger. Therefore, in order to more accurately determine that the internal combustion engine 10 switches from the driven state to the driven state, it is desirable to consider the influence of the vehicle speed V.
[0076]
Therefore, in the present embodiment, as shown in FIG. 5, the determination value ACCP1 related to the accelerator opening ACCP is set as a function of the vehicle speed V, and the larger the vehicle speed V, the larger the value. I have. Accordingly, as the vehicle speed V increases, it is determined that the vehicle running state and the engine operating state shift from the area A to the area B shown in FIG. 3, that is, the internal combustion engine 10 is switched from the driven state to the driven state. The accelerator opening ACCP increases. As a result, for example, when the accelerator opening ACCP is gradually increased from a low opening, the downshift is executed at an earlier stage as the vehicle speed V is lower.
[0077]
According to the present embodiment described above, the determination value ACCP1 relating to the accelerator opening ACCP for determining that the internal combustion engine 10 has switched from the driven state to the driven state is set to the running resistance that changes according to the air resistance or the like. Accordingly, the switching determination can be further enhanced in reliability.
[0078]
[Third Embodiment]
In the second embodiment, the determination value ACCP1 is set as a function of the vehicle speed V in order to consider a change in running resistance such as an air resistance that changes according to the vehicle speed V. Here, the running resistance changes depending on the state of the running road, that is, whether the running road is an uphill road or a downhill road, in addition to the air resistance that changes according to the vehicle speed V.
[0079]
Therefore, in the present embodiment, the gradient of the traveling road is estimated, and among the traveling resistances, the above-described determination value is set in consideration of a change due to the gradient of the traveling road, and the internal combustion engine 10 is set based on the determination value. The switching from the driven state to the driving state is determined.
[0080]
Hereinafter, a processing procedure for estimating the gradient of the traveling road (traveling road gradient estimation processing), a processing procedure for calculating the determination value based on the estimation result (determination value calculation processing), and the determination to be calculated The drive state change determination process based on the value will be described with reference to FIGS.
[0081]
FIG. 6 is a flowchart showing a processing procedure of the above-described travel road gradient estimation processing. A series of processing shown in this flowchart is periodically executed by the electronic control device 40 at a predetermined interrupt cycle.
[0082]
In this series of processing, first, the actual acceleration GACT of the vehicle is calculated based on the change in the vehicle speed V (step S300). Next, it is determined whether the accelerator opening ACCP is greater than "0", that is, whether the accelerator pedal 24 is depressed (step S310).
[0083]
Here, when the accelerator opening ACCP is “0”, that is, when the accelerator pedal 24 is not depressed (step S310: NO), the gradient DDWN of the downhill road is calculated based on the actual acceleration GACT calculated previously. (Downhill gradient) is calculated (step S350). In calculating the gradient DDWN, it is determined that the accelerator pedal 24 has not been depressed, that a predetermined time has elapsed since the accelerator opening ACCP became “0”, and that the braking operation is not performed. It is a condition. Here, when the actual acceleration GACT is larger than the predetermined value, it is estimated that the traveling road is a downhill road, and the gradient DDWN is calculated based on the actual acceleration GACT. Here, the gradient DDWN is a positive value, and the smaller the gradient DDWN, the more the vehicle is traveling on a steep downhill road.
[0084]
On the other hand, if the accelerator opening exceeds “0”, that is, if the accelerator pedal 24 is depressed (step S310: YES), then the engine torque is calculated based on the current intake air amount. (Step S320). Then, a reference acceleration GBASE is calculated based on the engine torque (step S330). Further, the gradient DUP (uphill gradient) of the uphill road is calculated based on the reference acceleration GBASE and the actual acceleration GACT (step S340).
[0085]
Note that the reference acceleration GBASE is an acceleration generated when the vehicle runs on a flat road with the engine torque calculated previously. Therefore, if the actual acceleration GACT substantially matches the reference acceleration GBASE, it can be estimated that the vehicle is traveling on a flat road. On the other hand, when the actual acceleration GACT is smaller than the reference acceleration GBASE, it can be estimated that the vehicle is traveling on an uphill road, and based on the deviation (GBASE-GACT) of these accelerations. The slope DUP on the road can be calculated. Here, the gradient DUP is a positive value, and the larger the gradient DUP is, the more the vehicle is traveling on an uphill road with a steep gradient.
[0086]
When the gradients DUP and DDWN on the uphill road and the downhill road are calculated in this way, this series of processing is temporarily ended.
FIG. 7 is a flowchart showing a processing procedure of the determination value calculation processing. A series of processing shown in this flowchart is periodically executed by the electronic control device 40 at a predetermined interrupt cycle.
[0087]
In this series of processing, first, it is determined whether or not the traveling path of the vehicle is an uphill road based on the result of the preceding traveling path gradient estimation processing (step S400). If it is determined that the road is an uphill road (step S400: YES), the uphill road determination value ACCUP is calculated based on the determination value ACCP1 and the uphill road gradient DUP shown in the first embodiment. (Step S410). On the other hand, when it is determined that the vehicle is on a downhill road (step S400: NO), the downhill road determination value ACCPDWN is calculated based on the determination value ACCP1 and the downhill gradient DDWN shown in the first embodiment. (Step S415).
[0088]
FIG. 8 is a calculation map showing the relationship between each of the gradients DUP, DDWN and each of the determination values ACCPUP, ACCPDWN. As shown by the one-dot chain line in the figure, the uphill grade determination value ACCUP is set to the standard value as the uphill gradient DUP increases when the slope DUP exceeds a predetermined value (> 0). It is set to a value gradually larger than ACCP1. On the other hand, as shown by the two-dot chain line in FIG. 3, when the gradient DDWN of the downhill road exceeds a predetermined value, the determination value ACCPDWN for the downhill road increases with the increase of the gradient DDWN. It gradually becomes smaller than that. Therefore, the following magnitude relationship is always established between the uphill road determination value ACCPUP and the downhill road determination value ACCPDWN.
[0089]
Uphill Decision Value ACCPUP> Downhill Decision Value ACCPDWN
The reason why the respective judgment values ACCPUP and ACCPDWN are set is as follows.
[0090]
The traveling resistance when the vehicle travels at a constant speed increases when the vehicle travels on an uphill road and decreases when the vehicle travels on a downhill road. Therefore, on an uphill road, the internal combustion engine 10 is driven under a higher engine load, in other words, under a larger accelerator opening ACCP, while on a downhill road, a smaller engine load (or accelerator opening ACCP). , The internal combustion engine 10 does not shift to the driving state. In consideration of this point, in the present embodiment, the magnitude relationship as shown in the above expression is set for the uphill road determination value ACCPP and the downhill road determination value ACCPDWN.
[0091]
In addition, the traveling resistance increases as the gradient DUP (uphill gradient) increases on an uphill road and the gradient DDWN (downhill gradient) decreases on a downhill road. In consideration of this point, in the present embodiment, when the traveling road is an uphill road, the ascending road determination value ACCCP is set to a larger value as the gradient DUP is larger. Further, when the traveling road is a downhill road, the descending road determination value ACCPDWN is set to a smaller value as the gradient DDWN is larger.
[0092]
As shown in FIG. 8, when the gradients DUP and DDWN are in the range near “0”, the estimation accuracy when estimating the traveling road as an uphill road or a downhill road is low. The determination value ACCPUP and the downhill road determination value ACCPDWN are made to match the standard determination value ACCP1. That is, when each of the gradients DUP and DDWN is in a range near “0”, the traveling road is regarded as a substantially flat road.
[0093]
In the present embodiment, when setting the determination value for determining the switching between the driven and the driven state of the internal combustion engine 10, the gradient of the traveling road is taken into consideration. Therefore, among the areas A to D defined in the downshift map shown in FIG. 3 above, the areas A and B are changed according to the state of the traveling road as shown in FIG. Become. That is, as shown in FIG. 9, when the vehicle is traveling on an uphill road, the uphill road determination value ACCPUP is set relatively small in accordance with the gradient DUP, so that the area of the area A Increases, and the area of the region B decreases by the increase. On the other hand, when the vehicle is traveling on a downhill road, the downhill road determination value ACCPDWN is set to be relatively large in accordance with the gradient DDWN. The area of the region B increases.
[0094]
As a result, when the vehicle running state and the engine operating state shift from the area A to the area B shown in FIG. 9 and the internal combustion engine 10 switches from the driven state to the driven state, the determination is earlier on a downhill road than on an uphill road. It will be done at the timing. Further, when the gradient DUP is small on an uphill road, and when the gradient DDWN is large on a downhill road, the switching is determined earlier.
[0095]
According to the embodiment described above, the following operational effects can be obtained.
According to the present embodiment, the determination value for determining whether the internal combustion engine 10 is switched between the driven state and the driven state is determined by the traveling resistance that changes according to the state of the traveling road, that is, whether the traveling road is an uphill road or a downhill road. Accordingly, the switching determination can be further enhanced in reliability.
[0096]
Further, the determination values ACCPUP and ACCPDWN can be appropriately set according to the gradients DUP and DDWN of the uphill road and the downhill road, and the reliability of the switching determination can be further improved. .
[0097]
The embodiments of the present invention have been described above. However, these embodiments can be implemented by partially changing the configuration and control structure as described below.
In the above embodiments, the timing at which the internal combustion engine 10 switches from the driven state to the driven state is determined based on the vehicle running state and the engine operating state. On the other hand, for example, a torque sensor is provided on the output shaft 18 of the automatic transmission 11, and it is monitored that the direction of the torque detected by the sensor is reversed, and the switching timing is determined based on the monitoring result. It may be.
[0098]
In setting the determination value for determining the above-mentioned switching in consideration of the running resistance, a change in air resistance caused by a change in the vehicle speed V as shown in the second embodiment is shown in the third embodiment. Both such changes due to the gradient of the traveling road may be considered together.
[0099]
-In a cold state or the like, the viscosity of the lubricating oil used in the drive system tends to be high, so that the drive resistance tends to increase. Therefore, for example, the temperature of the lubricating oil may be detected (or estimated from the engine cooling water temperature or the like), and the switching determination value may be corrected based on the lubricating oil temperature.
[0100]
In each of the above embodiments, the timing at which the internal combustion engine 10 switches from the driven state to the driven state is basically monitored based on the accelerator opening. It is also possible to change to a parameter having a correlation with the engine load, such as the throttle opening. Further, the engine speed may be monitored in combination with these parameters.
[0101]
-The process of step S230 of Fig. 2 shown in the first embodiment may be changed by replacing it with a series of processes shown in Fig. 10, for example. That is, as shown in FIG. 10, when a negative determination is made in step S220 in FIG. 2, the output from the output shaft 18 of the automatic transmission 11, such as the intake air amount, the gear position of the automatic transmission 11, the engine rotation speed, etc. The actual driving torque TACT is calculated based on various parameters that affect the driving torque to be performed (step S231). Next, based on the vehicle speed V, the gradients DUP, DDWN of the traveling road, and the like, a reference drive torque TBASE required to cause the vehicle to normally travel at the vehicle speed V is calculated (step S232). Then, the reference drive torque TBASE is compared with the actual drive torque TACT (step S233). Then, when it is determined that the reference drive torque TBASE is higher than the actual drive torque TACT (step S233: YES), the process proceeds to step S260 shown in FIG. On the other hand, when it is determined that the actual drive torque TACT is equal to or larger than the reference drive torque TBASE (step S233: NO), the process proceeds to step S240 shown in FIG. With such a configuration, the operation and effect similar to those of the device according to the first embodiment can be obtained, and the switching of the internal combustion engine 10 from the driven state to the driven state can be more accurately monitored. .
[0102]
In each of the above embodiments, the shift mode of the automatic transmission 11 is switched from the automatic shift mode to the manual shift mode when the shift position of the shift lever 28 is “M”. May be performed in any manner. For example, when a specific operation is performed on one or both of the shift switches 36 and 37 while the shift position of the shift lever 28 is “D”, the shift mode is switched to the manual shift mode. It may be.
[0103]
In the third embodiment, the gradient of the traveling road is estimated based on the comparison between the actual acceleration and the reference acceleration. However, for example, the gradient of the traveling road may be directly detected by a slope sensor or the like. Good.
[0104]
In each of the above embodiments, both the downshift switch 36 and the upshift switch 37 are provided on the steering wheel 26, but the arrangement thereof is also arbitrary. For example, the shift lever 28 may have the functions of the shift switches 36 and 37 together.
[0105]
In the above embodiments, the automatic transmission in which the gear is switched to four forward gears is described as an example. However, for example, an automatic transmission having three or less gears or five or more gears may be applied to the present invention. Such a device can be applied.
[0106]
In each of the above embodiments, a gear type transmission in which the gear stage of the automatic transmission can be switched only to a specific stage has been described as an example, but the device according to the present invention is limited to such a gear type automatic transmission. Not something. For example, in a continuously variable automatic transmission in which the gear ratio is continuously changed, the gear ratio can be selected only at a specific stage, and the gear mode is changed to a manual gear mode substantially equivalent to that of a gear type automatic transmission. The device according to the present invention can be applied as long as it can be changed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing the configuration of a shift control device for an automatic transmission according to the present invention.
FIG. 2 is a flowchart showing a processing procedure of a driving state change determination processing.
FIG. 3 is a map for setting downshift execution and execution time;
FIG. 4 is a flowchart showing a processing procedure of a downshift execution timing setting process.
FIG. 5 is a map for setting downshift execution and execution timing.
FIG. 6 is a flowchart showing a processing procedure of a traveling road gradient estimation process.
FIG. 7 is a flowchart showing a processing procedure when calculating a drive / drive state switching determination value of the internal combustion engine.
FIG. 8 is a calculation map for calculating a switching determination value of a driven / driven state of the internal combustion engine.
FIG. 9 is a map for setting execution of a downshift and its execution timing.
FIG. 10 is a flowchart illustrating a processing procedure of a modified example of the driving state change determination processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Automatic transmission, 12 ... Output shaft, 13 ... Intake passage, 14 ... Torque converter, 16 ... Transmission body, 18 ... Output shaft, 21 ... Throttle valve, 24 ... Accelerator pedal, 26 ... Steering Wheel, 28 shift lever (selection mechanism), 31 rotational speed sensor, 32 accelerator sensor (monitoring means), 33 vehicle speed sensor (monitoring means), 34 intake air amount sensor, 35 shift position sensor, 36 ... downshift switch (selection mechanism), 37 ... upshift switch (selection mechanism), 40 ... electronic control unit (monitoring means, estimation means, shift timing control means), 42 ... memory, V1 ... first predetermined speed, V2 ... second predetermined speed, V: vehicle speed.

Claims (8)

An automatic transmission mode in which the transmission ratio of the automatic transmission mounted on the vehicle internal combustion engine is automatically changed to a transmission ratio set based on the vehicle running state and the engine operating state, and the transmission ratio of the automatic transmission is selected. A manual transmission mode maintained at a transmission ratio selected through a mechanism, wherein the vehicle speed is equal to or less than a first predetermined speed set based on the maintained transmission ratio in the manual variable speed mode. A shift control device for an automatic transmission for a vehicle, which releases the holding of the gear ratio and increases the gear ratio when in the low speed range of
Monitoring means for monitoring that the internal combustion engine is switched from a driven state driven by the vehicle to a driving state for driving the vehicle,
A shift timing control unit that executes a process of increasing the speed ratio in accordance with the switching of the internal combustion engine from the driven state to the drive state based on the monitoring result of the monitoring unit. Gear shift control device. The shift control device for an automatic transmission according to claim 1,
When the vehicle speed shifts to a speed range equal to or lower than a second predetermined speed lower than the first predetermined speed in the low speed range, the shift timing control means forcibly operates regardless of whether the internal combustion engine is driven or driven. A shift control device for an automatic transmission, which executes the speed ratio increasing process. The shift control device for an automatic transmission according to claim 1 or 2,
A shift control device for an automatic transmission, wherein the monitoring means monitors switching from the driven state to the driven state based on an engine load. The shift control device for an automatic transmission according to claim 3,
A shift control device for an automatic transmission, wherein the monitoring means monitors a switch from the driven state to the drive state based on the accelerator operation amount using the accelerator operation amount of the internal combustion engine as the engine load. The shift control device for an automatic transmission according to claim 3 or 4,
The monitoring means determines that the internal combustion engine has switched from the driven state to the driven state based on a change in the engine load from a state less than a predetermined determination value to a value equal to or greater than the predetermined determination value in the low speed range. A shift control device for an automatic transmission. The shift control device for an automatic transmission according to claim 5,
The shift control device for an automatic transmission, wherein the monitoring means sets the predetermined determination value to be larger as the vehicle speed is higher. The shift control device for an automatic transmission according to claim 5 or 6,
The vehicle further includes estimating means for estimating a gradient of the traveling path of the vehicle,
The monitoring means automatically sets the predetermined determination value to a larger value when the travel path of the vehicle is estimated to be an uphill road by the estimation means than when the travel path is estimated to be a downhill road. Transmission control device for transmission. The shift control device for an automatic transmission according to claim 7,
When the traveling path of the vehicle is an uphill road, the monitoring means sets the predetermined determination value to a larger value as the gradient thereof is larger, while when the gradient of the vehicle is a descending road, A shift control device for an automatic transmission, wherein the predetermined determination value is set to a smaller value as the value becomes smaller.

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