| 摘要 |
PURPOSE: To reduce an oil consumption rate of the pilot valve of a variable transmission control valve with a minimum transmission ratio most frequently used by setting a pilot pressure with zero primary pressure by the variable transmission control valve of a pilot type current control mode, to some value close to zero, and setting the stepping ratio of a spool within a specific range. CONSTITUTION: An electronic hydraulic controller 40 in a belt type continuously variable transmission comprises a pilot type line pressure control valve 60 and a variable transmission control valve 70. The variable transmission control valve 70 comprises a pilot valve 74 for generating a pilot pressure in compliance with a solenoid electric current, the pilot pressure is loaded to one end of a stepping spool 72 and the elastic force, etc., of a spring 73 is loaded to the other end thereof so that variable transmission control may be carried out by controlling primary pressure Pp so as to set balance between both of the pilot pressure and the elastic force. Then, the variable transmission control valve 70 sets a pilot pressure Po under zero primary pressure Pp to a value close to zero, and sets the stepping ratio of the spool 72 from 1.11 to 1.50, so as to restrain the flow rate of oil consumption at the part of a pilot valve 74. |
