JPS58221052A - Speed change control method for electronic control type automatic speed change gear - Google Patents

Abstract

PURPOSE:To lengthen the period for replacing a bracke pad and a lining by shortening a return time of an accelerating pedal or shifting down a speed change mechanism at the time of stepping on the brake. CONSTITUTION:At the step 2, it is judged whether a throttle is rapidly closed or not by a signal from a throttle position sensor. If No, that is, in the case where the throttle is rapidkoy closed, it advances to the step 4. If YES, it advances to the step 3 to judge whether a brake switch is turned on or not. If YES, it advances to the step 4. At the step 4, the shift position is judged, and subsequently a shift down operation is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed change control method for an electronically controlled automatic transmission.

Conventionally, cars equipped with an automatic transmission (hereinafter referred to as automatic cars) have had the problem that brake pads and finnings wear out relatively faster than cars equipped with a manual transmission (hereinafter referred to as manual cars). Ta.

Although this poses no problem in practical terms, it leaves room for improvement in terms of simplifying maintenance and saving resources.

The present invention was made in view of the above circumstances, and aims to provide a speed change control method for an electronically controlled automatic transmission that can further lengthen the period for replacing brake pads and finings. It is something to do.

First, a conventional control method will be explained. FIG. 1 is a shift diagram of a conventional automatic vehicle.

In the same figure, point A is a throttle opening of 50 and a vehicle speed of 60.
km and the gear is in 3rd gear. When the driver takes his foot off the accelerator pedal while the vehicle is running, the throttle opening becomes zero, so taking into account the slight deceleration of the vehicle speed, the control system shifts to three points. That is, in the S general shift, the speed is shifted from 6th gear to overdrive (hereinafter referred to as 4th gear) and decelerated. Therefore, in this situation, it was not possible to expect much deceleration of the vehicle by engine braking. .

Next, the present embodiment will be explained. However, in the following explanation, an automatic transmission using a planetary gear unit will be explained as an example, but since this is already known, a brief explanation will be given here.

The rotation of the engine 1 is transmitted to the planetary gear unit 6 via the torque converter 2 including the lock-up clutch 2a, and after being shifted to a predetermined rotation, the rotation speed is detected by the vehicle speed sensor 4, and the rotation speed is detected by the differential gear 5. The signal is transmitted to the drive wheels 6 via the . The speed change of the planetary gear unit 6 is carried out by two solenoid valves 7a and 7b provided in the hydraulic control section Z and a servo mechanism 8 operated thereby. The up clutch 2a is operated by a solenoid valve 7 provided in the hydraulic control section 7.
Controlled by C. The relationship between the operating states (on, off) of the 7V noid valves 7a and 7b and the gears selected therefor is set as shown in Table 1 below.

However, in Table 1, the O mark indicates that the solenoid valve is energized (
This indicates that the solenoid valve is in the non-energized (hereinafter referred to as off) state 61C. Further, O and D in Table 1 indicate overdrive.

The solenoid valve 7a1 provided in the hydraulic control section 7
7b and 7C are connected to the microcomputer ECU, and the microcomputer ECU also includes a throttle position sensor 9 that detects the throttle opening.
, a detection signal from the vehicle speed sensor 4 , and a signal from the brake sensor 10 that detects whether the brake pedal is depressed or not are respectively inputted. In addition, this microcomputer ECU also has a knock sensor.

Signals from the engine water temperature sensor, altitude sensor, pattern select switch, etc. are input, but are omitted from the diagram.

The microcomputer ECU receives a signal related to the throttle opening from the throttle position sensor 9, a signal related to the vehicle speed from the vehicle speed sensor 4, and a brake sensor 10.
It inputs signals related to brake operation from the microcomputer ECU, and determines what speed to shift to according to the gear shift twin preset in the microcomputer ECU, and also outputs control signals for solenoid valves 7a, 7b, and 7C5. The configuration is such that the gears are switched by sending the respective signals.

Next, the tree/example control will be explained based on the flowchart shown in FIG.

First, in step 1, various data are taken in.

This data is from each of the sensors mentioned above, including throttle position sensor 9. JJ [Includes signals from speed sensor 4 and brake sensor 10.

This data is stored in the microcomputer ECU 1.
It can be set to RAM (not shown).

Next, in step 2, it is determined based on the signal from the throttle position sensor 9 whether or not the throttle of the engine (not shown) has been rapidly closed. This is based on a predetermined throttle opening θ1. θ2 (θ1>θ2) is set respectively, and the time required for the throttle opening to change from 01 to θ2 is determined based on whether the time I14'Itθ1→θ2 is larger than a preset reference time 1ljto. . And this judgment is N.

If the throttle is rapidly closed (that is, it is determined that υ deceleration is occurring), the process proceeds to step 4 and predetermined control is performed.

On the other hand, if the determination in step 2 is YES, the process proceeds to step 6, where it is determined whether the brake switch has been turned on. When this is YES, it is a deceleration state, so the process advances to step 4 and predetermined control is performed. On the other hand, at 140, the vehicle is not in a deceleration state;
Therefore, the process returns to the main routine (not shown).

Next, in step 4, the shift position is determined based on the signal regarding the shift position IW from the shift position Vyn sensor 10. Based on this judgment, the shift position is set to 4.
When the speed is high, go to step 9; when the speed is 6, go to step 5.
When the vehicle is in second gear, the process proceeds to step 7.

Here, to explain the case where the process proceeds to step 5 as an example, in step 5, the current vehicle speed V is set to a predetermined * speed V3 (this vehicle speed V3 is a speed at which the engine does not overrev when downshifting is performed). If the judgment is YES, that is, if it is smaller, proceed to step 6 and close the solenoid valve 71L.
Turn e on and shift down to 2nd gear. When the planetary gear unit 6 is in the state 5a, as shown in Table 1, the renoid valve 7 is turned off and 7b is turned on.
From this state, when solenoid pulp Z& is turned on, Table 1
A downshift to second gear is achieved as shown in FIG.

In this way, when the accelerator is suddenly released or the brake is stepped on, this is detected by the sensor and the planetary gear unit 8 is downshifted, so that the effect of engine braking is further increased by 1π than before.
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Further, as described above, since downshifting is performed only when the vehicle speed is below a predetermined speed (in step 5, when the speed is below V6), over-revving of the engine and shift shifting can be prevented at the same time.

Note that the same control as described above is performed when the shift position determination in step 4 determines that the gear is in the second or fourth gear.

That is, when the shift position is 2nd speed, the process proceeds to step 7 to determine the vehicle speed, and when it is less than v2, the process proceeds to step 8 to downshift to 1st speed. When the shift position is 4th gear, the process proceeds to step 9 to determine the vehicle speed, and when tL is less than v2, the process proceeds to step 10 to perform an S/downshift to 6a.

As explained above, in the present invention, when the accelerator is released quickly or the brake is depressed (including when both of the same conditions are satisfied), the microcomputer detects this and changes the transmission mechanism. Due to the shift control method of electronically controlled automatic transmissions that perform downshifts, it is possible to extend the period for replacing brake pads and finnings, which contributes to simplifying maintenance and saving resources. There is something big.

Note that the shift control method according to the present invention can be applied to any automatic transmission.

[Brief explanation of drawings]

The drawings show one embodiment embodying the present invention.
The figure is an explanatory diagram showing the speed change fin in the conventional control method.
The figure is an explanatory diagram showing an outline of the electronically controlled automatic 1IiJJ transmission, and FIG. 6 is a flowchart showing the speed change control in this example. 5... Planetary gear unit (speed change mechanism) 9...
Throttle position V! 1 sensor 10...Brake sensor ECU--Microcomputer

Claims (1)

[Claims] A gear change control method for an electronically controlled automatic transmission in which the gear shift of a transmission mechanism is controlled by a solenoid valve controlled by a microcomputer, and the above method is applied when the accelerator is released quickly or the brake is depressed. A shift control method for an electronically controlled automatic transmission, characterized in that a microcomputer detects this and downshifts the shift mechanism.