| 摘要 |
PURPOSE:To prevent the generation of shock by pressure-reducing the line pressure and supplying said pressure into a frictional element for engine brake at the max. speed stage and supplying the line pressure as it is at other speed stage, thus allowing the transmission capacity of the frictional element for engine brake to correspond to the speed change stage. CONSTITUTION:A pressure reducing valve 7 which discharges a portion of the working oil pressure from a drain port 7e and reduces pressure is inserted into the working-oil pressure circuit 9 of a frictional element 2 for engine brake. Though, when engine brake is performed at the max. speed stage, the line pressure pressure-reduced by the frictional element 2 is supplied, if engine brake is applied at other speed change stage, the line pressure is supplied into an engine brake control valve 6 through conduits 14 and 15, and then the line pressure is supplied into the drain port 7e of the pressure reducing valve 7 through a conduit 12. Therefore, the drain port 7e of the pressure reducing valve 7 is locked, and the line pressure is supplied into the frictional element 2 through a working oil pressure circuit 8. |
