Patent ID: 9193345
Filing Date: 2015-11-24
Classification: B60W,F16H,Y10T

Abstract:
1. An automatic transmission comprising: an input member disposed in a casing to receive power transferred from a drive source; a planetary gear set including a plurality of elements; a plurality of engagement mechanisms each capable of connecting the plurality of elements to each other or connecting the plurality of elements to the casing; an output member to output the power transferred from the input member, the output member having a first rotational speed different from a second rotational speed of the input member; a switching mechanism to switch a mode of one of the plurality of elements between a reverse rotation prevention mode in which a forward rotation is allowed and a reverse rotation is prevented and a fixed mode in which said one of the plurality of elements is fixed to the casing, the forward rotation representing a rotation in a direction to move a vehicle forward, the reverse rotation representing a rotation in a direction to move the vehicle backward; an engine braking determination device configured to determine based on predetermined vehicle information whether the vehicle is in an engine braking mode in which engine braking occurs; a vehicle speed detector configured to detect a travel speed of the vehicle; and a controller configured to control the plurality of engagement mechanisms and to control the switching mechanism to be in the reverse rotation prevention mode when a shift position is set to a forward drive range and to be in the fixed mode when the shift position is set to a reverse drive range, the controller being configured to prevent the switching mechanism from switching the mode from the fixed mode to the reverse rotation prevention mode when the shift position is changed from the reverse drive range to the forward drive range, and if the engine braking determination device determines that the vehicle is in the engine braking mode or if the travel speed of the vehicle detected by the vehicle speed detector is higher than a predetermined speed.