Hydraulic control system for a motor vehicle automatic transmission

Patent · Tue Aug 25 04:00:00 EDT 1987

OSTI ID:6050096

Aoyama, M; Fujiwara, T

A vehicle automatic transmission is described including a transmission gear mechanism having four gear stages including a 1st, 2nd, 3rd and 4th gear stages for forward drive, a 1-2 shift-valve for controlling shift operations between the 1st and 2nd gear stages, a 2-3 shift valve for controlling shift operations between the 2nd and 3rd gear stages, a 3-4 shift valve for controlling shift operations between the 3rd and 4th gear stages, kick-down valve means producing a kick-down pressure, a first kick-down line connecting the kick-down valve means with the 3-4 shift valve for applying kick-down pressure in a direction of biasing the 3-4 shift valve in a shift down direction, a second kick-down line connecting the kick-down valve means with the 2-3 shift valve for applying the kick-down pressure in a direction of biasing the 2-3 shift valve in a shift down direction, a first pilot type shut-off valve provided in the second kick-down line and having a first spool and a first pilot port at one end of the first spool, first means for connecting the first pilot port with a port in the 3-4 shift valve wherein a pressure change is produced when the 3-4 shift valve is moved in the shift down direction for opening the second kick-down line by moving the first spool under the pressure change to thereby connect the kick down valve means with the 2-3 shift valve to move the 2-3 shift valve in the shift down direction.

• Assignee: Mazda Motor Corp., Hiroshima
• Patent Number(s): US 4688452
• OSTI ID: 6050096
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
CONDUCTOR DEVICES
CONNECTORS
CONTROL
CONTROL EQUIPMENT
ELECTRICAL EQUIPMENT
EQUIPMENT
FLOW REGULATORS
GEARS
HYDRAULIC CONTROL DEVICES
MACHINE PARTS
MECHANICAL TRANSMISSIONS
PRESSURE CONTROL
PRESSURE EFFECTS
VALVES
VEHICLES