JPS6289560U

JPS6289560U -

Info

Publication number: JPS6289560U
Application number: JP18186385U
Authority: JP
Priority date: 1985-11-26
Filing date: 1985-11-26
Publication date: 1987-06-08

Description

[Brief explanation of the drawing]

第１図は本考案の自動変速機のロツクアツプ制
御回路の一実施例を示す概略構成図、第２図は従
来の自動変速機のロツクアツプ制御回路を示す概
略構成図である。１……トルクコンバータ、２……ロツクアツプ
クラツチ、３……締結圧回路、４……解除圧回路
、５……元圧供給回路、６……ロツクアツプコン
トロール弁、９……バイパス回路、１０……ドレ
ン回路、１２……クーラー、１３……オリフイス
、２０……ロツクアツプ制御回路、２１……可変
絞り手段。 FIG. 1 is a schematic diagram showing an embodiment of a lock-up control circuit for an automatic transmission according to the present invention, and FIG. 2 is a schematic diagram showing a lock-up control circuit for a conventional automatic transmission. DESCRIPTION OF SYMBOLS 1... Torque converter, 2... Lock-up clutch, 3... Engaging pressure circuit, 4... Release pressure circuit, 5... Source pressure supply circuit, 6... Lock-up control valve, 9... Bypass circuit, 10 ... Drain circuit, 12 ... Cooler, 13 ... Orifice, 20 ... Lock-up control circuit, 21 ... Variable throttle means.

Claims

[Scope of utility model registration request]

A torque converter has a lock-up clutch that is locked up by supplying lock-up engagement pressure and released by supplying lock-up release pressure; a engagement pressure circuit that supplies the lock-up engagement pressure; The lock-up control valve is provided between the supply release pressure circuit and the lock-up control valve for switching the connection between one of the engagement pressure and release pressure circuits and the source pressure supply circuit, and the lock-up control valve is provided between the engagement pressure circuit and the release pressure circuit. A bypass circuit with an orifice that bypasses the lock-up control valve and a drain circuit that is connected to the lock-up pressure circuit when the lock-up control valve is switched to the release pressure circuit side are provided, and after these bypass circuit and drain circuit, In an automatic transmission in which a cooler is disposed on the flow side to cool the working fluid, the release pressure circuit includes:
1. A lock-up control circuit for an automatic transmission, characterized in that a variable throttle means is provided that reduces the diameter of the throttle when the release pressure in the torque converter is low, and increases the diameter of the throttle when the release pressure is high.