| 摘要 |
PURPOSE:To keep the line pressure within a designated change range in case of a failure by supplying oil pressure obtained by reducing the line pressure by a reducing valve to a regulator valve as the pilot pressure or auxiliary oil pressure by an increase in value. CONSTITUTION:The pressing force of a spring member 58B for pressing a spool 58A built in a regulator valve 53 can be set a value increased by the pressing force corresponding to the auxiliary oil pressure, as compared with the case where the second oil path 65 for supplying the auxiliary oil pressure is not provided in a regulator valve 53. Accordingly, for example, when there causes a failure that a spool of a reducing valve 58 is fixed in a condition where oil pressure is abnormally low due to the reduction of the line pressure and the pilot pressure and the auxiliary oil pressure supplied to the regulator valve 53 are abnormally low values, the line pressure formed by the regulator valve 53 is made correspond to the pressing force of a spring member increased in the pressing force so as to supply operating oil pressure which will not damage the speed change operation of a hydraulic transmission remarkably to an operating oil pressure supply portion. |
