HYDRAULIC CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To surely prevent the internal locking of a transmission and making a device respondent to different requests for speed change due to the difference of an driving condition by making constitution for adjusting switching timing of a switching valve switching a joint pressure passage to a communicated condition. CONSTITUTION:When the releasing oil pressure of one end chamber 83e exceeds a set pressure value obtained by subtracting the energizing force of a spring 83b from the joint oil pressure of the other end chamber 83f, the joint oil pressure is supplied to a coast clutch 42 by moving a spool 83a toward a right direction by a pressure difference. When the joint oil pressure is released to the other end chamber 83f, the joint oil pressure of a joint pressure passage 127 is supplied to a port 83d and concurrently the joint oil pressure is supplied to the coast clutch 42 by moving the spool 83a toward the right direction by the energizing force of the spring 83b. This composes an adjusting means in which the movement timing of the spool 83a as the supply timing of the joint oil pressure to the coast clutch 42 can be adjusted with a 1-2 shift valve.