JP3627456B2 - Shift control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift control device for an automatic transmission, and more particularly to a manual shift mode for performing a shift that causes a stepwise change in a gear ratio by an upshift command or a downshift command based on a driver's manual operation, and a driving state. The present invention relates to a shift control device for an automatic transmission capable of selecting an automatic shift mode in which shifting is performed.
[0002]
[Prior art]
In a vehicle equipped with an automatic transmission, when an automatic shift range (D range) is selected, a shift is automatically performed based on a traveling state such as a vehicle speed or an engine load (throttle opening). However, even in a vehicle equipped with such an automatic transmission, a driver may desire a shift operation feeling like a manual transmission. In view of this requirement, an automatic transmission with a manual range (M range) that can shift to a predetermined gear stage by a driver's manual operation is proposed, for example, in Japanese Patent Laid-Open No. 5-320202. .
[0003]
In such an automatic transmission with an M range, when the driver performs an upshift command or a downshift command that causes a stepwise change in the gear ratio by manual operation when the M range is selected, the gear position corresponding to the command is changed. For example, when the downshift command is repeated twice at the fourth speed, the shift from the fourth speed to the second speed is performed.
[0004]
[Problems to be solved by the invention]
However, in the conventional automatic transmission with M range described above, even when the driver repeats the downshift command three or more times by manual operation when the M range is selected, the downshift command is unconditionally issued. Therefore, the shift from the “current shift speed” to the “shift speed that is three or more steps lower than the current shift speed” is performed. As a result, for example, when the downshift command is repeated three times at the fourth speed, the shift from the fourth speed to the first speed is performed, which may give the driver a feeling of excessive engine braking. .
[0005]
According to the present invention, the limit of the downshift to be permitted when a downshift gear shift command that gives an excessive engine brake feeling to the driver in the manual shift mode is set to a gear position that is two steps lower than the current gear position. It aims at solving the above-mentioned problem by doing.
[0006]
[Means for Solving the Problems]
For the above purpose, the configuration of claim 1 of the present invention includes a manual shift mode for performing a shift that causes a stepwise change in gear ratio by an upshift command or a downshift command based on a manual operation by the driver, and a traveling state. In an automatic transmission shift control device capable of selecting an automatic shift mode for performing a shift based on the engine brake determining means for determining whether or not the engine brake is being operated, and when it is determined that the engine brake is being operated, the driver Downshift limiting means for permitting an additional downshift command during the downshift in the manual shift mode only once so as not to give an excessive engine braking feeling to the vehicle. is there.
[0007]
According to the first aspect of the present invention, when it is determined that the engine brake is in operation, in the manual shift mode in which a shift that causes a stepwise change in the gear ratio is generated by an upshift command or a downshift command based on a manual operation by the driver. If an additional downshift command is issued more than once during the downshift operation, the additional downshift command is allowed only once so that the driver does not feel excessive engine braking. On the other hand, a downshift to a shift stage that is lower than three stages is prohibited.
[0008]
According to a second aspect of the present invention, the engine brake determining means according to the first aspect is configured such that when the throttle opening is equal to or less than a preset threshold value, or when the longitudinal acceleration of the vehicle is equal to or less than a preset threshold value, It is determined that the brake is operating.
[0009]
According to claim 2 of the present invention, when the throttle opening is less than or equal to a preset threshold value, or when the longitudinal acceleration of the vehicle is less than or equal to a preset threshold value, it is determined that the engine brake is in operation. .
[0010]
According to a third aspect of the present invention, in the first aspect, the engine brake determining means is configured to perform engine braking when the throttle opening is equal to or less than a preset threshold value and the longitudinal acceleration of the vehicle is equal to or less than a preset threshold value. It is determined that it is operating.
[0011]
According to claim 3 of the present invention, if the throttle opening is less than or equal to a preset threshold, and at the same time, if the longitudinal acceleration of the vehicle is less than or equal to a preset threshold, it is determined that the engine brake is operating. Is done.
[0012]
【The invention's effect】
According to claim 1 of the present invention, an additional downshift command during execution of the downshift while the engine brake is operating in the manual shift mode is allowed only once, so that the driver feels excessive engine braking. A downshift to a gear position that is three or more steps lower than the current gear position can be prohibited, and driving feeling is improved.
[0013]
According to claim 2 of the present invention, whether or not the engine brake is in operation is determined depending on whether or not the determination condition based on the throttle opening or the determination condition based on the longitudinal acceleration of the vehicle is satisfied. Can be judged well.
[0014]
According to claim 3 of the present invention, whether or not the engine brake is in operation is further determined by simultaneously satisfying both the determination condition based on the throttle opening and the determination condition based on the longitudinal acceleration of the vehicle. Can be judged well.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing functional blocks of a shift control device for an automatic transmission according to a first embodiment of the present invention. In this embodiment, a continuously variable transmission is used as the automatic transmission.
In general, a continuously variable transmission represented by a V-belt type continuously variable transmission and a toroidal type continuously variable transmission obtains a target gear ratio from a running condition such as an engine load requirement and a vehicle speed, and the actual gear ratio is the target gear ratio. Shift control is performed to achieve a ratio. The continuously variable transmission according to the present embodiment can set a stepped gear ratio, determine the first to sixth gears, and perform a shift to the gears manually by the driver. Thus, it is configured as a continuously variable transmission with a manual range (M range).
[0016]
Although not shown, the speed change control device 10 shown in FIG. 1 spans a V belt between a primary pulley that is an input side pulley and a secondary pulley that is an output side pulley, and changes the V groove width of both pulleys. Thus, the speed change control device is configured for a V-belt type continuously variable transmission that can change the gear ratio steplessly by changing the winding arc diameter of the V belt around these pulleys.
[0017]
The transmission control device 10 includes a signal from a primary pulley rotation sensor 11 that detects the rotation speed N _pri of the primary pulley,
A signal from the secondary pulley rotation sensor 12 for detecting the rotation speed N _sec of the secondary pulley;
A signal from the vehicle speed sensor 13 for detecting the vehicle speed VSP;
A signal from a throttle opening sensor 14 for detecting the throttle opening TVO of the engine in the preceding stage of the continuously variable transmission;
Selected range of the continuously variable transmission and a signal from the (parking range P, the reverse traveling range R, the forward normal driving range D, the forward sport travel range D _S) inhibitor switch 15 for detecting,
A signal from the M range switch 16 for detecting a manual travel range (M range) of the continuously variable transmission;
M range command shift speed detection sensor for detecting an M range command shift speed (first speed M1 ^* to sixth speed M6 ^* ) corresponding to operation of an upshift switch and a downshift switch (both not shown) in the M range. 17 is input.
[0018]
In the present embodiment, the shift control device 10 is particularly configured as follows.
The M range shift speed determining unit 20 is based on the throttle opening TVO detected by the sensor 14 and the M range command shift speed (first speed M1 ^* to sixth speed M6 ^* ) detected by the M range command shift speed detection sensor 17. Further, the M range gear (first speed M1 to sixth speed M6) is determined by executing a control program of FIG. 3 to be described later.
The target primary rotational speed calculation unit 21 includes a vehicle speed VSP and a throttle opening TVO detected by the sensors 13 and 14, a selected range position detected by the inhibitor switch 15 and the M range switch 16, and an M range shift stage determination unit 20. from the determined M range gear position (first speed M1~ sixth speed M6), the shift map corresponding to the shift diagram for the D range of FIG. 2 (a), the shift for the D _S range in FIG (b) The target primary rotation speed N _pri ^* is searched based on the shift map corresponding to the diagram and the shift map corresponding to the shift diagram for the M range in FIG.
[0019]
The final target speed ratio calculating unit 22 divides the target primary rotational speed N _pri ^* by the rotational speed N _sec of the secondary pulley to thereby obtain the final (steady) target speed ratio i _P0 (= N _pri ^* / N _sec ). Is calculated.
The speed ratio limiter 23 limits the upper limit value and the lower limit value of the final target speed ratio i _P0 to the hardware limit values and outputs them to the transient target speed ratio calculation unit 24. The final target speed ratio i _{P0 is described} below. What is referred to as "" means the final target speed ratio after being limited in this way.
The actual gear ratio calculation unit 25 divides the rotation speed N _pri of the primary pulley detected by the sensor 11 by the rotation speed N _sec of the secondary pulley detected by the sensor 12, so that the actual gear ratio i _P (= N _pri / N _sec )
The target speed ratio deviation calculating unit 26 is a target speed ratio deviation e _iP between the final target speed ratio i _P0 from the speed ratio limiter 23 and the transient target speed ratio i _PT obtained by the transient target speed ratio calculating unit 24. (= I _P0 −i _PT ) is calculated.
[0020]
The time constant calculating unit 27 selects the vehicle speed VSP and the throttle opening TVO detected by the sensors 13 and 14, the selection range from the inhibitor switch 15 (parking range P, reverse travel range R, forward normal travel range D, forward sport travel range D. _S ), a signal related to the manual travel range (M) from the M range switch 16, a signal related to the M range shift stage (first speed M1 to sixth speed M6) determined by the M range shift stage determination unit 20, and the above-mentioned A target speed ratio deviation e _iP is inputted, and a time constant T of the shift control is determined based on the input information.
Here the time constant T, the final target speed ratio i _P0 to determine the responsiveness of the transient target speed ratio i _PT for intended for determining the shift speed, the transient target transmission ratio calculation unit 24 is the final target speed ratio i _P0 Is used when the transient target speed ratio i _PT is calculated from the above.
[0021]
The lower limiter 28 and the change speed upper limiter 29 limit the lower limit value of the time constant T and the upper limit of the change speed obtained by the time constant calculator 27 and input them to the transient target gear ratio calculator 24. In the following description, the term “time constant T” means all time constants after the lower limit value and the upper limit of the change rate are limited by the lower limiter 28 and the change rate upper limiter 29.
The transient target speed ratio calculation unit 24 uses the final target speed ratio i _P0 from the speed ratio limiter 23 described above, the time constant T, and the Laplace operator S to determine the transient target speed ratio i _PT , i _PT = [1 / (1 + T)] i _P0 and outputs this to the motor drive signal calculator 30.
[0022]
Motor drive signal computation unit 30 calculates the motor drive signal to match accordance with the deviation between the transient target speed ratio i _PT and the actual gear ratio i _P, the actual gear ratio i _P in transient target speed ratio i _PT, This is output to the stepping motor 31 for shift control of the continuously variable transmission.
The step motor 31 strokes a shift control valve (not shown) in response to the drive signal, and shifts the continuously variable transmission to the above-described transient target gear ratio i _PT by the shift control hydraulic pressure from now on.
[0023]
Next, the determination of the M range gear position in the present embodiment will be described in detail. FIG. 3 is a flowchart showing a control program for determining the M range shift stage executed by the M range shift stage determining unit 20 in the first embodiment. This control program is used in the M mode of the continuously variable transmission (M range selection). When).
[0024]
In the control program of FIG. 3, first, in step 51, based on the M range command shift speed (any one of the first speed M1 ^* to the sixth speed M6 ^* ) detected by the M range command shift speed detection sensor 17, It is determined whether or not a downshift gear shift command is issued to a gear position lower than the current M range gear position (Mi = any one of the first speed M1 to the sixth speed M6), and the downshift gear shift command is issued. Control proceeds to step 52 only if
In step 52, it is determined whether or not a downshift is being performed. The determination in step 52 is NO only for the first control (immediately after selection of the M range), and the control proceeds to step 53. In step 53, the current M range shift stage CurGp is lowered by one stage (CurGp = CurGp-1). On the other hand, after the second control, the determination at step 52 is YES, and the control proceeds to step 54.
[0025]
In step 54, it is determined whether or not the engine brake operation by whether the throttle opening TVO detected by the throttle opening sensor 14 is a threshold TVO ₀ below the preset. The determination in step 54 is NO when the driver depresses the accelerator, and the control proceeds to step 53 where the current M range shift stage CurGp is lowered by one stage. On the other hand, when the driver performs the accelerator release operation, the determination in step 54 is YES, and the control proceeds to step 55.
[0026]
In step 55, it is determined whether or not the counter value C is zero. In step 55, since the counter value C has been reset to 0 at the end of the previous shift, the first control is YES, and control proceeds to step 56. In step 56, after the counter value C is incremented (C = C + 1), the control proceeds to step 53, and the current M range shift stage CurGp is lowered by one stage. On the other hand, after the second control, the determination at step 55 is NO, so the control proceeds to step 57, where the current M range gear stage CurGp is held (CurGp = CurGp).
[0027]
Next, the operation of this embodiment will be described.
In the continuously variable transmission, when switching from the D range selection state to the M range, the M speed range (Mi = first speed M1 to sixth speed M6) has a speed ratio closest to the current speed ratio. When the M range is selected, the control program shown in FIG. 3 is started.
By the way, in the continuously variable transmission, when the M range is selected, the driver may instruct a shift to an M range shift stage that is three or more steps lower than the current M range shift stage by pressing the downshift switch a plurality of times. For example, when the downshift switch is pressed three times in the M range fourth speed, a downshift from the fourth speed to the first speed is commanded. In this case, if the downshift command is allowed as it is, there is a risk of giving the driver an excessive engine braking feeling during a 4 → 1 shift.
[0028]
Therefore, in the present embodiment, when the M range is selected, for example, when a downshift command from the fourth speed to the first speed is issued, first of step 51 in the control program of FIG. The downshift from the 4th speed to the 3rd speed is permitted by the execution, and then the third by the execution of YES of step 51 -YES of step 52 -YES of step 54 -YES of step 55 -step 56 -step 53 The downshift from the second speed to the second speed is allowed, and then the second speed is decreased from the second speed to the first speed by executing YES in step 51 -YES in step 52 -YES in step 54 -NO in step 55 -step 57 The shift is prohibited and the second speed is maintained. As a result, a downshift to a gear position that is three or more lower than the current gear position that gives the driver a feeling of excessive engine braking is prohibited, and driving feeling is improved.
[0029]
In the first embodiment, the case where a continuously variable transmission is used as the automatic transmission has been described. Needless to say, the present invention can also be applied to a configuration using a stepped automatic transmission.
In the first embodiment, when the throttle opening TVO detected by the throttle opening sensor 14 is equal to or less than the preset threshold TVO ₀ , it is determined that the engine brake is operating. the case where the signal G from the sensor (longitudinal acceleration sensor) for detecting a longitudinal acceleration threshold G ₀ below the preset may be determined that during operation the engine brake. Further, when the throttle opening TVO is equal to or less than a preset threshold value TVO ₀ and when the longitudinal acceleration G of the vehicle is equal to or less than G ₀ , it may be determined that the engine brake is operating. The accuracy of judgment is improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing functional blocks of a shift control device for an automatic transmission according to a first embodiment of the present invention.
Figure 2 (a), (b), (c) respectively show the target primary pulley speed of the continuously variable transmission used as an automatic transmission in the first embodiment, the D-range, the D _S range It is a shift control pattern diagram for the M range.
FIG. 3 is a flowchart showing a control program for determining an M range shift speed executed by an M range shift speed determining unit in the first embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Shift control apparatus 11 Primary pulley rotation sensor 12 Secondary pulley rotation sensor 13 Vehicle speed sensor 14 Throttle opening sensor 15 Inhibitor switch 16 M range switch 17 M range shift stage detection sensor 20 M range shift stage determination part 21 Target primary rotation speed calculation part 22 final target gear ratio calculation unit 23 gear ratio limiter 24 transient target gear ratio calculation unit 25 actual gear ratio calculation unit 26 target gear ratio deviation calculation unit 27 time constant calculation unit 28 time constant lower limit limiter 29 time constant change speed upper limit limiter 30 motor Drive signal calculation unit 31 Step motor for shift control

Claims (3)

Automatic transmission that allows selection between a manual shift mode that changes gears that cause a stepwise change in gear ratio according to an upshift command or a downshift command that is based on a driver's manual operation, and an automatic shift mode that changes gears based on driving conditions In the gear shift control device of the machine,
Engine brake determination means for determining whether or not the engine brake is in operation;
Downshift limiting means for permitting only one additional downshift command during the downshift in the manual shift mode so as not to give the driver a feeling of excessive engine braking when it is determined that the engine brake is being operated; A shift control device for an automatic transmission, comprising: 2. The engine brake determination unit according to claim 1, wherein the engine brake determination unit determines that the engine brake is in operation when the throttle opening is equal to or less than a preset threshold value or when the longitudinal acceleration of the vehicle is equal to or less than a preset threshold value. Shift control device for automatic transmission. 2. The automatic engine according to claim 1, wherein the engine brake determining means determines that the engine brake is in operation when the throttle opening is equal to or less than a preset threshold value and the longitudinal acceleration of the vehicle is equal to or less than a preset threshold value. A transmission control device for a transmission.

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