Control gear of automatic gearbox

Abstract

The invention provides a control device of automatic gearbox, which can be used in an oil pressure control of lock-up clutch during speed change, thereby preventing oil pressure reduction caused by speed change prepration pressure, and appropriately adjusting oil pressure in required area for the lock-up clutch, and not only inhibiting slipping of the lock-up clutch, but also preventing generation of abnormal noise. When the oil pressure instruction of the lock-up clutch is sent, whether the speed change instruction for a speed change mechanism is sent is judged; if the speed change instruction is sent, summing of adjusting oil pressures (PA) for the control oil pressure (P) for the lock-up mechanism is carried out. Moreover, a timer (TM) is set used from summing the adjusting oil pressures (PA) to the end. The timer (TM) is set as that the adjusting oil pressures (PA) are summed after the speed change signals are connected and the ending is before the speed change mechanism begins to change speed.

Description

technical field [0001] The present invention relates to a control device for an automatic transmission having a torque converter with a lock-up clutch, and more particularly to a control device for controlling the engagement capacity of the lock-up clutch. Background technique [0002] In an automatic transmission for a vehicle, as disclosed in, for example, Patent Documents 1 and 2, a lock-up clutch capable of mechanically coupling an output shaft of an engine and an input shaft of an automatic transmission is provided in a torque converter. In addition, by engaging the lock-up clutch under certain conditions, the engine speed is kept low and fuel efficiency is improved. [0003] Normally, the lock-up clutch is engaged when the gear stage set by the automatic transmission is a predetermined gear stage. However, when the lock-up clutch is fully engaged, shocks and torque fluctuations transmitted between the input shaft and the output shaft cannot be absorbed. Therefore, sl...

AI Technical Summary

Problems solved by technology

As a result, compared with the case where the engagement capacity (slip ratio) of the lockup clutch is controlled to the target slip ratio, the supplied oil pressure is too high, and the lockup clutch becomes a state closer to being fully engaged (a so-called stuck state). ), thus having the problem of generating abnormal noise (click) in the shifting mechanism

On the other hand, if the above correction oil pressure is not applied to the lock-up clutch or the applied correction oil pressure is reduced in order to prevent the generation of the abnormal noise, it is difficult to suppress the slipping of the lock-up clutch when shifting.

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