JPH06307531A - Speed change control method of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent frequent speed change operation by slight operation of an accelerator by keeping a speed change ratio smaller than a maximum speed change ratio at a level no more than a specific throttle opening and a specific car speed when the change-over switch is switched from a normal traveling side to a traffic jam traveling side. CONSTITUTION:The output of an engine 1 is transmitted to a transmission mechanism 4 via the torque converter 3 of an automatic transmission 2. The discharged oil from an oil pump 5 driven by the torque converter 3 is pressure- fed to an oil pressure controller 6, and the friction factors of the transmission mechanism 4 are thus controlled. The solenoids 31-34 of the oil pressure controller 6 are controlled by an A/T control 30 based on the output signals from the sensors 13-15 for detecting the drive condition of the engine 1. A change-over switch 16 between a normal traveling side and a traffic jam traveling side is connected to the A/T controller 30. A speed change ratio smaller than a maximum speed change ratio is kept at a level no more than a specific throttle opening and a specific car speed at the time of switching of the traffic jam traveling side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control method for an automatic transmission for a vehicle, and more particularly to a shift control during traffic congestion.

[0002]

2. Description of the Related Art Generally, in the case of an automatic transmission for a vehicle, shift control is performed according to a traveling mode map set in correspondence with a vehicle speed and a throttle opening. FIG. 1 shows an example thereof, in which solid lines are upshift lines and broken lines are downshift lines. When a vehicle equipped with such an automatic transmission runs slowly on a congested road, it travels in a low throttle opening and low vehicle speed region as indicated by the shaded area in FIG. 1, so a slight accelerator operation is required. As a result, up-shifting and down-shifting are frequently repeated, which causes a driver discomfort. Further, during such traffic congestion, starting and stopping are frequently repeated, but the maximum gear ratio is selected as the gear position (gear ratio) at the time of starting in order to ensure the starting acceleration. Therefore, if the accelerator is roughly operated during a traffic jam, a large fluctuation of the driving torque will occur and the vehicle will be jerky, resulting in deterioration of the riding comfort of the vehicle.

In order to eliminate such discomfort during traffic congestion, it is possible to automatically detect that the vehicle is traveling on a traffic congestion road and perform automatic shifting in a shift pattern suitable for traffic congestion traveling. A control device has been proposed (JP-A-4-5).
No. 0549). As a shift pattern suitable for traveling in a traffic jam, for example, a gear position having a smaller gear ratio than that of a shift pattern for traveling on a general road is selected.

[0004]

However, in the case of this shift control device, the fact that the vehicle is traveling on a congested road is automatically detected by referring to the throttle opening and the vehicle speed in time series. There was a drawback that it was difficult to immediately respond to the change from traffic jam driving to normal driving when the traffic jam was resolved. Also,
Even when approaching a congested road, the driver is most aware of whether or not the congestion will continue for a long period of time.Therefore, in the method in which the automatic transmission automatically determines the shift pattern, the driver's own intention is reflected. There are difficult problems. Therefore, an object of the present invention is to provide a shift control method for an automatic transmission for a vehicle that eliminates discomfort during traffic congestion and can immediately respond to a change from traffic congestion to normal driving.

[0005]

In order to achieve the above object, the present invention relates to an automatic transmission for a vehicle, which performs a shift control according to a preset shift pattern from a vehicle speed and a throttle opening, in a normal traveling mode by a manual operation. Side, and equipped with a changeover switch that can be selectively switched between traffic congestion side,
When the changeover switch is switched to the traffic congestion running side, it is held at a gear ratio smaller than the maximum gear ratio in the range where the throttle opening is below a certain value and below a certain vehicle speed, and in other areas, gear shifting is performed according to the shift pattern during normal running. It's something that you do.

[0006]

When the vehicle approaches a traffic jam, the driver switches the changeover switch from the normal travel mode map to the traffic jam mode map. In the traffic jam driving mode map, the gear ratio smaller than the maximum gear ratio is held in a region where the throttle opening is equal to or less than the certain speed and the vehicle speed is less than the certain vehicle speed, and the same gear ratio as that in the normal driving mode map is selected in other regions. Therefore, when the vehicle speed is low and the throttle opening is low, the gear ratio smaller than the maximum gear ratio (for example, the second speed or the third speed) is maintained, and frequent shift-up and shift-down can be prevented and the vehicle By reducing the drive torque, it is possible to prevent jerky running even if the accelerator is roughly operated. Further, when the traffic jam is resolved, the shift switch is switched to the normal traveling mode map or the accelerator pedal is depressed, whereby the shift control suitable for the normal traveling can be immediately shifted.

[0007]

2 is a system diagram of a vehicle for carrying out a shift control method according to the present invention. The output of the engine 1 is transmitted to the speed change mechanism 4 via the torque converter 3 of the automatic transmission 2, and the speed change mechanism 4 is connected to wheels (not shown). The automatic transmission 2 includes an oil pump 5 driven by a torque converter 3, and the oil discharged from the oil pump 5 is sent to a hydraulic control device 6. The hydraulic control device 6 controls the hydraulic pressure of various friction elements such as a shift clutch and a brake built in the speed change mechanism 4 according to the vehicle speed and the throttle opening.

Throttle sensor 13, input rotation sensor 1
4 and vehicle speed sensor 15 signals are input to the A / T controller 30. The A / T controller 30 is a computer that compares and arithmetically processes an input signal and setting data according to a predetermined program and performs line pressure control, lockup control, and shift control, and is provided in the hydraulic control device 6. A command signal is output to the generated solenoids 31 to 34. Of these, 31 is a line pressure control solenoid, 32 is a lockup solenoid, and 33 and 34 are shift control solenoids. Is linearly regulated.

The A / T controller 30 has a normal traveling mode map suitable for normal traveling as shown in FIG.
As shown in, a traffic jam driving mode map suitable for traffic jam driving is set. In particular, in the traffic jam driving mode map, the third speed is set in a region where the throttle opening θ _{1 is} less than or equal to and the vehicle speed V _{1 is} less than the constant, and in other regions, the same gear ratio is set in the normal driving mode map. ing. A
The changeover switch 16 is connected to the / T controller 30. The changeover switch 16 selectively switches between the normal traveling mode map and the traffic jam traveling mode map by a manual operation.

When traveling in a traffic jam, the vehicle often travels in the shaded area in FIG. 3, but in this area the traffic jam mode map is held at the third speed, and therefore, a slight accelerator operation frequently causes an upshift and a downshift. It does not repeat and does not cause driver discomfort. Also, when the vehicle is running in a traffic jam, it often starts and stops repeatedly, but since the gear position (gear ratio) at the start is the third speed, the driving torque is small even if the accelerator is operated roughly, so it was jerky. You can prevent running. Although the driving torque is insufficient when the vehicle starts at the third speed, the engine 1 and the transmission mechanism 4
Since the torque is amplified by the torque converter 3 provided between and, smooth start is possible. It should be noted that if the accelerator pedal is strongly depressed while the vehicle is traveling in the traffic jam travel mode map, the gears are shifted in the same shift pattern as in the normal travel mode map.
You can accelerate quickly without operating.

Next, the shift control method according to the present invention will be described with reference to FIG. First, various signals such as the throttle opening, the input rotation speed, and the vehicle speed are input to the A / T controller 30 (step 40), and then the changeover switch 16 is switched to either the normal driving mode map side or the congestion driving mode map side. It is determined whether or not (step 41). If it is on the normal traveling mode map side, shift control is executed according to the shift pattern of FIG. 1 (step 42). On the other hand, on the side of the traffic jam traveling mode map, the shift control may be executed according to the shift pattern of FIG. 3 (step 43).

In the above embodiment, the example in which the two traveling mode maps, that is, the ordinary traveling mode map and the traffic jam traveling mode map, are set has been described, but the shift control may be executed by the method shown in FIG. That is, signal input (step 50)
After that, the position of the changeover switch 16 is determined (step 5
1) If the changeover switch 16 is on the normal traveling mode map side, shift control is performed according to the normal traveling mode map (step 52). On the other hand, if the changeover switch 16 is on the traffic jam mode map side, then it is determined whether the throttle opening is a constant value θ ₁ or less (step 53) and whether the vehicle speed is a constant value V ₁ or less (step 53). 54) is performed. If the throttle opening is θ ₁ or less and the vehicle speed is V ₁
In the following cases, the gear ratio is held at the third speed (step 55), and in other cases, gear change control is performed according to the normal traveling mode map (step 52). In the case of the shift control method as described above, it is not necessary to set a single map data as the traffic jam driving mode map, so there is an advantage that the memory capacity can be reduced.

In the above embodiment, only one type of normal driving mode map is shown, but a plurality of types of normal driving mode map may be set and any one of them may be selected by the changeover switch. Further, in the present invention, the changeover switch may be left as it is while being switched to the traffic jam traveling mode side. Therefore, when the throttle opening is opened to θ ₁ or more, the changeover switch may be automatically switched to the normal traveling mode side. In addition, when the power is turned off in the state where the traffic mode is switched to the traffic jam mode, the mode may be automatically switched to the normal mode when the power is turned on next time.

[0013]

As is apparent from the above description, according to the present invention, when the changeover switch is switched to the traffic jam mode, the maximum gear ratio is lower than the maximum gear ratio in a region where the throttle opening is equal to or less than and the vehicle speed is equal to or less than a certain speed. Since it is held at a small gear ratio and the gear shift is performed according to the gear shift pattern during normal running in other regions, frequent upshifts and downshifts can be prevented by a slight accelerator operation, and the vehicle The driving torque is reduced, and it is possible to prevent jerky running. Further, if the changeover switch is switched to the normal traveling mode map or the accelerator is depressed, the vehicle can travel in a normal gear shift pattern, so that the shift control suitable for normal traveling can be immediately shifted.

[Brief description of drawings]

FIG. 1 is a travel mode map diagram during normal travel.

FIG. 2 is a system diagram of a shift control system according to the present invention.

FIG. 3 is a travel mode map diagram during traffic jam travel.

FIG. 4 is a flowchart showing an example of a shift control method of the present invention.

FIG. 5 is a flowchart of another example of the shift control method according to the present invention.

[Explanation of symbols]

 2 Automatic transmission 13 Throttle sensor 15 Vehicle speed sensor 30 A / T controller

Claims (1)

[Claims] 1. An automatic transmission for a vehicle, which performs shift control according to a preset shift pattern from a vehicle speed and a throttle opening, and a changeover switch that can be selectively switched between a normal traveling side and a congested traveling side by a manual operation. When the changeover switch is switched to the traffic congestion side, it is held at a gear ratio smaller than the maximum gear ratio in the range below a certain throttle opening and below a certain vehicle speed, and in other areas, according to the shift pattern during normal running. A shift control method for an automatic transmission for a vehicle, characterized in that a shift is performed.