JP4197867B2 - Shift control device for automatic transmission for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift control device for a vehicular automatic transmission, and more particularly to a shift pattern switching control during uphill traveling.
[0002]
[Prior art]
Conventionally, as a technology for controlling to a gear stage suitable for climbing, from a normal shift pattern to a climbing shift pattern, such as switching to a climbing shift map or prohibiting shifting to overdrive in an uphill running state Switching control is known.
[0003]
Further, in the device disclosed in Japanese Patent Laid-Open No. Hei 7-066361, even if the uphill traveling state is determined, the throttle opening is not immediately switched to the uphill shifting pattern, but the throttle opening is equal to or higher than a certain reference value, or After the speed of change of the throttle opening exceeds a certain reference value, or even in a normal shift pattern, the shift is performed in accordance with the uphill shift pattern, which is not intended by the driver. Shifting is prevented from being performed.
[0004]
[Problems to be solved by the invention]
However, in the configuration in which the shift to the uphill shifting pattern is performed after the throttle opening exceeds a certain reference value, if the reference value is high, the vehicle will be lowered if the accelerator is not depressed greatly when the vehicle is in the uphill driving state at a low opening. If the reference value is set low, the original purpose of avoiding the gear shift not intended by the driver cannot be achieved.
[0005]
In addition, in the configuration in which the speed change rate of the throttle opening changes to a certain reference value or more and then switches to the uphill shift pattern, when the accelerator is frequently operated to adjust the vehicle speed in the low opening range, the driver's intention Downshifting may occur.
Furthermore, in the configuration in which the shift to the uphill shift pattern is performed after the shift is performed even in the normal shift pattern, the shift characteristic demands that the downhill is positively downshifted even when the accelerator is depressed lighter than the flat road. There was a problem that it could not fit.
[0006]
The present invention has been made in view of the above-described problems, and it is possible to perform a downshift without greatly delaying the driver's acceleration intention while avoiding a gear change not intended by the driver when traveling uphill. An object of the present invention is to provide a shift control device for an automatic transmission for a vehicle.
[0007]
[Means for Solving the Problems]
Therefore, in the first aspect of the invention, when it is detected that the vehicle is in the uphill traveling state, a switching request from the normal shift pattern to the uphill shifting pattern is determined, and after the switching request is determined, When the accelerator depression speed becomes equal to or greater than a predetermined value set to a smaller value as the accelerator opening is larger , the normal shift pattern is switched to the uphill shift pattern.
[0008]
According to the above configuration, the driver's intention to accelerate is determined from the accelerator depressing speed, and switching to the uphill shifting pattern is executed. However, the level of the depressing speed for determining the acceleration intention depends on the accelerator opening at that time. Will be changed accordingly .
[0009]
Furthermore, since the predetermined value to be compared with the accelerator depression speed is set to a smaller value as the accelerator opening is larger, switching to the uphill shifting pattern is possible even in the area where the accelerator opening is large, even at a relatively slow depression speed. On the other hand, in the region where the accelerator opening is small, unless the accelerator is depressed relatively quickly, the shift pattern for the uphill is not switched.
[0010]
According to the second aspect of the present invention, when it is detected that the vehicle is in an uphill traveling state, a request for switching from the normal shift pattern to the shift pattern for uphill is determined, and after the request for switching is determined, the accelerator is When the stepping speed of the vehicle is greater than or equal to a predetermined value set to a smaller value as the accelerator opening is larger, switching from the normal shift pattern to the shifting pattern for climbing is performed, and the stepping speed of the accelerator is When the accelerator opening is less than the predetermined value and the accelerator opening is greater than the predetermined value from the accelerator opening at the time when the switching request is determined, switching from the normal shift pattern to the uphill shift pattern is executed. The configuration.
[0011]
According to the above configuration, after the switching request to the uphill shift pattern is determined, depression speed of the accelerator, if more than a predetermined value the accelerator opening is set to a smaller value larger at that time, shifting uphill If the accelerator opening is greater than the accelerator opening at the time when the switching request is determined even if the accelerator depression speed is less than the predetermined value, the climbing to the pattern is performed. Switch to the gear shift pattern.
[0012]
【The invention's effect】
According to the first aspect of the present invention, if the accelerator is not depressed more quickly in the low opening range, the shift pattern for the uphill is not switched. Therefore, the uphill shifting pattern is achieved by the accelerator operation for adjusting the vehicle speed in the low opening range. Thus, there is an effect that the switching to the uphill shift pattern can be appropriately performed.
[0014]
According to the second aspect of the present invention, it is possible to accurately determine the driver's intention to accelerate from the accelerator depression speed in conformity with the accelerator operation characteristics for each accelerator opening range, and even if the accelerator depression speed is low, The driver's intention to accelerate can be accurately determined from the accelerator depression amount based on the accelerator opening at the time when the request for switching to the shift pattern is determined, so that the switch to the shift pattern for climbing can be performed appropriately. There is an effect that can be.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram showing a system configuration of a shift control apparatus for a vehicle automatic transmission.
In FIG. 1, an automatic transmission 2 connected to the output side of the engine 1 performs a fastening / releasing operation of a torque converter 3, a gear-type transmission 4, and various friction engagement elements in the gear-type transmission 4. And a control valve 5 for performing.
[0016]
The supply of the hydraulic pressure to the control valve 5 is controlled by a shift solenoid, a line pressure solenoid, a lock-up solenoid or the like, but only the shift solenoids 6A and 6B for shifting are shown here.
Signals are input from various sensors to the control unit 7 that controls the shift solenoids 6A and 6B.
[0017]
The various sensors include a vehicle speed sensor 9 that detects a vehicle speed VSP by obtaining a rotation signal from the output shaft 8 of the automatic transmission 2, and an opening TVO (accelerator opening) of a throttle valve 10 that opens and closes in conjunction with the accelerator. A throttle sensor 11 for detecting, a turbine sensor 12 for detecting the turbine rotational speed Nt of the torque converter 3 and the like are provided.
[0018]
The control unit 7 refers to a basic shift map in which the shift speed is stored in advance corresponding to the vehicle speed VSP and the throttle opening TVO, and the shift solenoid 6A, The combination of ON and OFF of 6B is controlled, and the gear type transmission 4 is controlled to the gear stage via the control valve 5.
[0019]
Further, when the vehicle is traveling uphill, the basic shift map is switched to an uphill shift map adapted to the uphill travel, and the shift solenoids 6A and 6B are turned ON / OFF according to the shift speed determined from the uphill shift map. Control the combination.
The flowchart in FIG. 2 shows the switching control to the uphill shift map (uphill shift control).
[0020]
In the flowchart of FIG. 2, in step S1, the gradient i (%) of the road surface on which the vehicle is traveling is calculated.
In calculating the road surface gradient i, first, the gradient resistance Ri is calculated.
The gradient resistance Ri is based on the current driving force F1, acceleration resistance Ra, rolling / air resistance Rrl,
Ri = F1-Ra-Rrl
Is calculated as
[0021]
Here, the current driving force F1 is based on the turbine torque Tt calculated based on the current throttle opening TVO and the turbine rotational speed Nt, the gear ratio RATIO, and the constant k1 determined by the tire radius and the like.
F1 = Tt × RATIO × k1
Is calculated as
[0022]
Further, the acceleration resistance Ra is obtained from the amount of change ΔVSP per unit time of the vehicle speed VSP, the vehicle weight W, and the constant k2.
Ra = ΔVSP × W × k2
Is calculated as
Further, the rolling / air resistance Rrl is calculated based on the vehicle speed VSP.
[0023]
The gradient resistance Ri and the road inclination angle θ are:
Ri = W · sinθ
Therefore, the inclination angle θ is obtained from the above equation, and the gradient i is based on the inclination angle θ.
i = tan θ × 100 (%)
Is calculated as
[0024]
However, instead of estimating and calculating the road surface gradient i as described above, the road surface gradient i is detected by an inclination sensor that detects the inclination of the vehicle, or estimated from information on the geographical traveling position, The configuration may be such that information on the road surface gradient i is read from the outside.
In step S2, whether or not there is a request for switching to the uphill shift map is determined based on the road surface gradient i. Specifically, when it is determined that the vehicle is traveling on an uphill with a predetermined slope or more, it is determined that there is a request for switching to the uphill shift map.
[0025]
In step S3, it is determined whether or not there is a request for switching to the uphill shift map.
If it is determined that there is a request to switch to the uphill shift map, the process proceeds to step S4, where the throttle opening change speed DTVO, in other words, the accelerator depression speed is calculated from the amount of change in the throttle opening TVO over a certain period of time. To do.
[0026]
In step S5, a threshold value DTVOSL of the change speed DTVO is set based on the current throttle opening TVO.
As shown in the flowchart, the threshold value DTVOSL is set to a smaller value as the throttle opening TVO is larger.
In step S6, it is determined whether or not the change speed DTVO is greater than a threshold value DTVOSL.
[0027]
When it is determined that the change speed DTVO is larger than the threshold value DTVOSL and the accelerator is depressed at a speed equal to or higher than a predetermined speed, the process proceeds to step S7, and switching to the uphill shift map is executed.
On the other hand, when the change speed DTVO is equal to or lower than the threshold value DTVOSL, the routine is terminated by bypassing step S7.
[0028]
Therefore, even if it is determined that there is a request for switching to the uphill shift map, the basic shift map is not actually switched to the uphill shift map until the accelerator is depressed at a change speed DTVO greater than the threshold value DTVOSL. The shift control based on is continued.
As described above, if it is determined that there is a request for switching to the uphill shift map and then the accelerator is depressed at a change speed DTVO greater than the threshold value DTVOSL, then the driver switches to the uphill shift map. Downshifts that are not intended for acceleration are avoided.
[0029]
Further, if the threshold value DTVOSL of the change speed DTVO is increased in a region where the throttle opening TVO is small, it is determined that the driver intends to accelerate when the accelerator is operated for vehicle speed adjustment in the low opening range. In the high opening range where the driver is demanding high output, the downshift can be performed without delaying the driver's request.
[0030]
The flowchart of FIG. 3 shows a second embodiment of the switching control to the uphill shift map (uphill shift control).
In steps S11 to S13, as in steps S1 to S3, it is determined whether or not there is a request for switching to the uphill shift map based on the road gradient i.
If it is determined in step S13 that there is a request for switching to the uphill shift map, the process proceeds to step S14, and it is determined whether or not it has been determined that there is also a switching request in the previous time.
[0031]
If it was determined that there was no switching request last time, this is the first determination that there is a switching request. In this case, the process proceeds to step S15, and the throttle opening TVO at that time is determined as the reference opening. Set to MTVO.
In steps S16 to S18, as in steps S4 to S6, it is determined whether or not the change speed DTVO of the throttle opening TVO is equal to or greater than a threshold value DTVOSL that is set to be smaller as the throttle opening TVO is larger. .
[0032]
If the change speed DTVO is greater than the threshold value DTVOSL, the process proceeds to step S21 to switch to the uphill shift map.
If it is determined in step S18 that the change speed DTVO is equal to or less than the threshold value DTVOSL, the process proceeds to step S19 to calculate a deviation TVOSA between the current throttle opening TVO and the reference opening MTVO.
[0033]
TVOSA = TVO-MTVO
Since the reference opening MTVO is the throttle opening TVO when it is determined that there is a request for switching to the uphill shift map for the first time, the deviation TVOSA is determined to be the first request for switching to the uphill shift map. The amount of change in throttle opening TVO from the point in time (accelerator depression amount) is shown.
[0034]
In step S20, the deviation TVOSA is compared with a threshold value SASL stored in advance.
When the deviation TVOSA is larger than the threshold value SASL, the process proceeds to step S21 to switch to the uphill shift map.
On the other hand, when the change speed DTVO is equal to or less than the threshold value DTVOSL and the deviation TVOSA is equal to or less than the threshold value SASL, this routine is terminated without executing switching to the uphill shift map.
[0035]
In the second embodiment, even if the accelerator is not depressed at a speed exceeding the threshold value DTVOSL, the accelerator depression amount from the time when it is first determined that there is a request for switching to the uphill shift map exceeds the threshold value SASL. At that time, switching to the uphill shift map is executed.
Therefore, even if the depression speed is slow, if the accelerator is depressed more than a predetermined amount for acceleration on the uphill road, it will be switched to the uphill shift map, and the driver's acceleration intention will be detected accurately and the optimum A downshift can be performed at the timing.
[0036]
Further, since the accelerator depression amount is based on the time point when it is first determined that there is a request for switching to the uphill shift map, it is possible to accurately determine the uphill depression regardless of the opening range .
[0037]
In the first and second embodiments, the switching from the basic shift map to the uphill shift map is performed from the normal shift pattern to the uphill shift pattern. The shift to overdrive may be prohibited, and the method of realizing the uphill shift pattern is not limited to the shift map switching.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a shift control device for an automatic transmission for a vehicle.
FIG. 2 is a flowchart showing a first embodiment of uphill shift control.
FIG. 3 is a flowchart showing a second embodiment of uphill shift control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Automatic transmission 3 ... Torque converter 4 ... Gear type transmission 5 ... Control valve 6A, 6B ... Shift solenoid 7 ... Control unit 9 ... Vehicle speed sensor 10 ... Throttle valve 11 ... Throttle sensor 12 ... Turbine sensor

Claims (2)

When it is detected that the vehicle is in an uphill driving state, a request for switching from a normal shift pattern to a climbing shift pattern is determined, and after the switch request is determined, the accelerator depression speed is determined by the accelerator opening degree. A shift control apparatus for an automatic transmission for a vehicle, wherein the switching from the normal shift pattern to the uphill shift pattern is executed when the value becomes equal to or greater than a predetermined value set as a smaller value as the value increases. When it is detected that the vehicle is in an uphill driving state, a request for switching from a normal shift pattern to a climbing shift pattern is determined, and after the switch request is determined, the accelerator depression speed is determined by the accelerator opening degree. When the value becomes equal to or greater than a predetermined value set as a smaller value as the value increases, switching from the normal shift pattern to the uphill shift pattern is performed, and the accelerator depression speed is less than the predetermined value and the accelerator Switching from the normal shift pattern to the uphill shift pattern is performed when the opening is greater than a predetermined value from the accelerator opening at the time when the switching request is determined. A transmission control device for a transmission.

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