HYDRAULIC CONTROL DEVICE OF AUTOMATIC TRANSMISSION

• Main Authors: KAMATA SHINYA, SAJI TSUNESHIRO, NAGAI SHOTARO
• Format: Patent
• Language: English; Japanese
• Published: 11.12.2014
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MECHANICAL ENGINEERING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To prevent a defect of a gear change operation caused by the fact that fastening hydraulic pressure is simultaneously supplied to three friction fastening elements due to a malfunction of a hydraulic control valve, in an automatic transmission which forms respective gear change stages by fastening two friction fastening elements.SOLUTION: In a constitution in which a first gear is formed by fastening an LR brake 60 and a low clutch 40, a third speed is formed by fastening a low clutch 40 and an R35-brake 80, and a retreat speed is formed by fastening the LR brake 60 and the R35-brake 80, the constitution comprises a cut valve 121 which is switched to a first state that an original pressure port of a third linear SV 113 for controlling hydraulic pressure supplied to the R35-brake 80 to a hydraulic pressure source, and a second state that the original pressure port is discharged in pressure. When the hydraulic pressure supplied to the low clutch 40 is lower than prescribed hydraulic pressure at a gear change of 3 to 1, the cut valve 121 is brought into the second state. 【課題】 ２つの摩擦締結要素の締結によって各変速段を形成する自動変速機において、油圧制御弁の不調により、３つの摩擦締結要素に締結用油圧が同時に供給されることによる変速動作不良を防止する。【解決手段】 ＬＲブレーキ６０とロークラッチ４０の締結によって１速が形成され、ロークラッチ４０とＲ３５ブレーキ８０の締結によって３速が形成され、ＬＲブレーキ６０とＲ３５ブレーキ８０の締結によって後退速が形成される構成において、Ｒ３５ブレーキ８０に供給される油圧を制御する第３リニアＳＶ１１３の元圧ポートを油圧源に接続する第１状態と、該元圧ポートを排圧させる第２状態とに切り換わるカットバルブ１２１を備え、３→１変速時に、前記ロークラッチ４０に供給されている油圧が所定油圧未満のときに、前記カットバルブ１２１が第２状態となるように構成する。【選択図】 図８