HYDRAULIC CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

• Main Authors: KAMATA SHINYA, SAJI TSUNESHIRO
• Format: Patent
• Language: English; Japanese
• Published: 28.04.2016
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To suppress overload on an electric pump supplying a hydraulic pressure to a friction coupling element during idle stop of an engine and furthermore to reduce a capacity of the electric pump, in an automatic transmission including the electric pump.SOLUTION: A hydraulic control device for an automatic transmission is provided which includes a mechanical pump 6 driven by an engine, an electric pump 106 operated during automatic stop of an engine, friction coupling elements 40, 60 coupled upon starting a vehicle, and a hydraulic circuit 100 for controlling supply of hydraulic pressure to the friction coupling elements, the hydraulic circuit 100 being provided with a switching valve 120 capable of switching a first condition in which the mechanical pump 6 is functioned as a hydraulic pressure supply source to the friction coupling elements 40, 60, and a second condition in which the electric pump 106 is functioned as the hydraulic pressure supply source. In the hydraulic control device, the hydraulic circuit 100 is constituted in such a way that discharge oil from the electric pump 106 is drained from a prescribed draining portion 154 when the switching valve 120 is in the first condition, and when the switching valve 120 is in the second condition, the draining is suppressed in comparison with that in the first condition.SELECTED DRAWING: Figure 3 【課題】エンジンのアイドルストップ中に摩擦締結要素へ油圧供給する電動ポンプを備えた自動変速機において、電動ポンプの過負荷を抑制しつつ、電動ポンプの容量低減を図る。【解決手段】エンジンによって駆動される機械ポンプ６と、エンジンの自動停止中に作動する電動ポンプ１０６と、車両発進時に締結される摩擦締結要素４０，６０と、該摩擦締結要素への油圧供給を制御するための油圧回路１００と、を備え、該油圧回路１００に、摩擦締結要素４０，６０への油圧供給源を機械ポンプ６とする第１状態と、油圧供給源を電動ポンプ１０６とする第２状態との間で切り換え可能な切換弁１２０が設けられた自動変速機の油圧制御装置において、切換弁１２０が第１状態にあるときに、電動ポンプ１０６からの吐出油を所定のドレン部１５４からドレンさせ、且つ、第２状態にあるときは第１状態にあるときに比べて前記ドレンを抑制するように、油圧回路１００を構成する。【選択図】図３