JP2554934B2 - Transmission control device for automatic transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for controlling a shift of an automatic transmission.

<Prior Art> A vehicle equipped with an automatic transmission with a torque converter is conventionally known to perform a shift according to a preset shift pattern based on a vehicle speed and a throttle valve opening. (See Japanese Utility Model Publication No. 62-194231, etc.).

<Problems to be Solved by the Invention> However, since the conventional gear shift control is performed independently of the cornering operation, the gear shifting is performed during the cornering operation, resulting in unstable traveling.

The present invention has been made in view of the above-mentioned conventional problems, and by performing gear shift control based on the bending state of the road surface obtained based on the detection information of the steering angle of the steering wheel, during cornering operation. However, it is an object of the present invention to provide a shift control device for an automatic transmission that is capable of performing stable shift control.

<Means for Solving the Problems> Therefore, as shown by the solid line in FIG. 1, the present invention is a gear shift control device for automatically controlling the gear shift position according to the driving condition, and detects the steering angle of the steering wheel. Steering angle detecting means, integrating means for integrating a plurality of turning angles detected by the turning angle detecting means within a predetermined time, and averaging for averaging the turning angles integrated by the integrating means When the processing means, the road surface determination means for determining the bending state of the road surface based on the turning angle averaged by the averaging processing means, and the road surface state with a high bending rate, the shift point is usually And a curved road surface shift pattern selecting means for selecting a curved road surface shift pattern that is shifted to a higher vehicle speed side than the traveling shift pattern and performing shift control.

Further, as shown by a dotted line in the figure, when the current steering angle is large, a gear shift permission / denial means may be included to permit the gear shift only when the lower limit engine speed set for the vehicle speed is exceeded. .

<Operation> The turning angle detecting means detects the turning angle of the steering wheel,
The integrating means integrates the plurality of turning angles detected by the turning angle detecting means within a predetermined time, the averaging processing means averages the integrated turning angles, and the road surface determining means , The bending state of the road surface is determined based on the steered angle that has been averaged. The bent road surface shift pattern selection means, when it is determined that the road surface state has a high bending rate, the shift point for the bent road surface is such that the shift point is shifted to a higher vehicle speed side than the shift pattern for normal traveling. To control gear shifting.

When the gear shift permission / denial means is included, the gear shift permission / denial means permits the gear shift only when the current steering angle is large and at or above the lower limit engine speed set for the vehicle speed.

<Example> Below, the Example of this invention is described based on drawing.

Referring to FIG. 2 showing the configuration of an embodiment, an automatic transmission 1 including a torque converter and a transmission.
In order to control the hydraulic pressure of each transmission element such as front clutch, rear clutch, brake band, low & reverse brake, one-way clutch,
Solenoid valves 2A to 2E are provided which are interposed in hydraulic passages guided by these and control the operating hydraulic pressure by controlling the valve opening duty thereof.

On the other hand, a throttle sensor 3 for detecting the opening degree of a throttle valve interposed in an engine passage (not shown), and a rotation speed sensor 4 mounted near the crankshaft or built in a distributor for detecting the engine rotation speed N are provided. To be In addition, the vehicle speed V near the output shaft of the transmission
A vehicle speed sensor 5 for detecting the gear position and a gear position sensor 6 for detecting a gear position G (shift position) are provided in the transmission.

Further, a turning angle sensor 7 is provided as a turning angle detecting means for detecting the turning angle S _a of the steering wheel. For this, for example, the one disclosed in Japanese Utility Model Laid-Open No. 62-158302 is used.

Each signal detected by these is input to the control unit 8.

The control unit 8 is configured by incorporating a microcomputer, determines the gear shift point of the transmission in consideration of the steering angle information based on the signals from the respective sensors, and opens the solenoid valves 2A to 2E. Shift control is performed by controlling the duty.

The shift control will be described below with reference to the flowcharts shown in FIGS. 3 and 4.

FIG. 3 shows a routine for measuring the turning state based on the information from the turning angle sensor 7. This routine is executed every unit time (for example, 1 _SEC ).

In step (denoted as S in the figure) 1, the steering angle sensor 7
The detected value of the steering angle S _a is read from.

In step 2, the steering coefficient f preset according to the detected value of the steering angle S _a is searched from the map (see the drawing) stored in the ROM.

In step 3, the integrated value Σ _n f of the steering coefficient f is obtained (Σ _n f = Σ _n-1 f + f). The function of step 3 corresponds to the integrating means.

In step 4, the average value f _m of the steered coefficients f searched in the predetermined time section (for example, 60 _SEC ) n ₀ is calculated by the following equation.

_{fm = (Σ n f-Σ} n-n0 f) / n 0 The function of this Step 4 is equivalent to averaging means.

FIG. 4 shows a routine of gear shift control according to the bending state of the road surface obtained based on the information on the turning state obtained in FIG.

In step 11, the detected values of the current engine speed N, throttle valve opening θ, vehicle speed V, gear position G, and steering angle S _a are read.

In step 12, a flag F which is set when the road surface condition has a high bending rate is determined by the determination described later.

Then, when the flag F is not set, the routine proceeds to step 13, where the standard shift pattern set according to the vehicle speed V and the throttle valve opening θ is selected as in the conventional case, but the flag F is set. If yes, step 14
Going to, the shift pattern for curved road surface is selected.

The curved road surface shift pattern is also set based on the vehicle speed V and the throttle valve opening θ, but as shown in the figure, the throttle valve opening θ is about a correction, and the shift point is set based on the vehicle speed V. It has a characteristic that it is fixed at a low gear position (low, or second / low two-stage switching) at an intermediate vehicle speed or lower. For simplicity, the vehicle speed V alone may be set at the shift point. The function of steps 12 and 14 constitutes a bent road surface shift pattern selection means.

Next, at step 15, the current steering angle S _a is the predetermined value S _a0
It is determined whether or not the size is the above, that is, whether or not the current traveling condition is a cornering operation with a large bend.

And when the steering angle is relatively small such that S _a <S _a0 ,
Proceeding to step 16, the target gear position G _a searched by the shift pattern selected in step 13 or step 14
And the current gear position G are compared to make a shift determination.

When both gear positions are not coincident with each other in the above judgment, the routine proceeds to step 17, where the gear position is shifted to the gear position searched by the shift pattern. When they are coincident with each other, the gear is not shifted and the routine proceeds to step 18.

In step 18, it is determined whether or not the flag F for bending road surface determination is set based on the average value f _m of the steering coefficient f obtained in the routine of FIG.

Specifically, when f _m is equal to or greater than a predetermined value f _m0 , it is determined to set the flag F, and when f _m is less than the predetermined value f _m0 , determination is made to reset the flag F, but hunting is prevented and stability is provided. For this reason, the predetermined value f _m0 has a predetermined width of hysteresis Δf.

According to the determination in step 18, the flag F is set in step 19, and the flag F is reset in step 20.

In addition, since the shift pattern is switched by switching between setting and resetting the flag F according to the steering state,
This is done not at the shift point but at the most stable running state even during cornering (during gear shifting or during cornering, hunting of gear shifting may be caused).

On the other hand, when it is determined in step 15 that S _a ≧ S _a0 ,
Proceed to step 21, and similar to step 16, the target gear position G searched by the shift pattern selected in step 14
Shift determination is performed by comparing _a with the current gear position G.

Then, when the gear positions match, this routine is terminated without performing gear shifting, but when they do not match, the routine proceeds to step 22.

In step 22, based on the vehicle speed V and the engine speed N,
Whether or not shifting is permitted is determined based on a map stored in ROM in advance. Specifically, as shown in the figure, in a region where the current engine speed N is equal to or higher than the lower limit engine speed N ₀ set for the vehicle speed V, gear shifting is permitted, but is lower than the lower limit engine speed N _0. In the area of, the judgment is made to prohibit the shift. In other words, if the engine torque is large enough to allow stable running even when gear shifting is performed, the vehicle speed should be increased early even during cornering. To secure the sex.

If the vehicle speed is permitted based on the above judgment, step
The routine proceeds to 17 and shifts to the gear position searched for by the shift pattern, but if it is determined that shift is prohibited, this routine is terminated without shifting.

The routine of FIG. 3 and steps 18, 19, 20 of FIG.
Function of the road surface determination means, and the function of steps 22 and 17 form the gear shift permission / denial means.

<Effects of the Invention> As described above, according to the present invention, when a road surface situation with a high bending rate is determined based on the detection information of the turning state, the vehicle is fixed at a low gear position or during large cornering. The stable cornering traveling property can be obtained by performing the control for suppressing the shift, such as permitting the shift only when the torque has a sufficient margin.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, and FIG. 2 is
FIG. 3 is a diagram showing a configuration of an embodiment of the present invention, FIG. 3 is a flowchart showing a steering state determination routine of the same embodiment, and FIG.
The figure is a flow chart showing a shift control routine of the above embodiment. 1 ... Automatic transmission, 2A-2E ... Solenoid valve, 3 ...
Throttle sensor, 4 ... Revolution sensor, 5 ... Vehicle speed sensor, 6 ... Gear position sensor, 7 ... Steering angle sensor, 8
……control unit

Claims (2)

(57) [Claims] 1. A shift control device for automatically switching a shift position according to operating conditions, comprising: a steering angle detecting means for detecting a steering angle of a steering; and a steering angle detecting means for detecting a steering angle within a predetermined time. A totalizing means for integrating the turning angles of a plurality of times, an averaging processing means for averaging the turning angles integrated by the integrating means, and a turning angle averaged by the averaging processing means. A road surface determining means for determining a road surface bending state based on the road surface, and a road surface for a bent road surface in which the shift point is shifted to a higher vehicle speed side as compared with a shift pattern for normal traveling when it is determined that the road surface state has a high bending rate. A shift control device for an automatic transmission, comprising: a bent road surface shift pattern selecting means for selecting a shift pattern for controlling the shift. 2. The automatic transmission according to claim 1, further comprising a gear shift permission / denial means for permitting a gear shift only when the current steering angle is large and at least the lower limit engine speed set for the vehicle speed. Shift control device.