| 摘要 |
<p>PURPOSE:To suppress generation of a transmitting shock by connecting a hydraulic pilot pressure relief valve, by which supply oil from a clutch upper side location is partly discharged only in a predetermined range, to the clutch upper side location of a pressure oil supply path. CONSTITUTION:A pressure relief valve 15 is interposed in a discharge oil path 16 formed between a clutch upper side location 8a and a tank T. The first pilot oil path 17 is connected to a valve upper side of the discharge oil path 16, and the second pilot oil path 18 in the other side is connected to a high speed operation side oil path 19 of a subtransmission operating hydraulic cylinder T3. In a condition that a subtransmission is selected to a low speed side, that is, when the second pilot oil path 18 is placed in an oil discharge condition, and when supply pressure increasing action is started gradually by a boost mechanism, the pressure relief valve 15 is set to a communication position (d) to discharge partly supply pressure oil only in the vicinity of a predetermined pressure adjacent to a clutch meet pressure in the boost characteristic. Accordingly, a rapid increase of supply pressure, at the time of clutch meet, can be suppressed.</p> |
