Versagensschutzmechanismus für ein Automatikgetriebe und in dem Versagensschutzmechanismus vorgesehenes Versagensschutzventil

摘要

In a fail-safe mechanism for an automatic transmission (3), when a predetermined gearshift (Rev) is positioned in the automatic transmission (3) during a non-failure state of the automatic transmission, a first valve unit (70) moves from a non-failure position toward a failure position as the oil pressure for positioning the predetermined gearshift (Rev) is caused to act on a fail-safe valve (50) as an extraneous matter-discharging oil pressure (PR).