| 摘要 |
PURPOSE:To improve a speed change response characteristic, by temporarily increasing a line pressure higher than at normal time under a condition necessary for a rapid speed change to prevent a V-belt from slipping at the rapid speed change. CONSTITUTION:When a speed change operating mechanism 112 is moved largely or rapidly to any of the directions, pressure of oil in pulley cylinder chambers 28 and 44 is changed, before a speed change is started, a spool 152 is moved to communicate a port 122g to a port 122f or 122h. In consequence, oil in a port 118i of a line pressure regulating valve 102 is discharged through an oil path 1,001, the ports 122g and 122f or 122h. Accordingly, leftward force applied to a spool 132 of the valve 102 is decreased, and line pressure of a port 118h is increased so as to compensate a decrease of said force. That is, the line pressure increases at a rapid speed change to improve a speed change response characteristic. |
