A control device executes, when a jump-down shifting is executed, shifting control in which, after engaging elements establishing a pre-shifting gear position are released, an intermediate gear position that is a gear position between the pre-shifting gear position and a post-shifting gear position is established, and after the intermediate gear position is established, the post-shifting gear position is established. When an engaging element able to reduce a rotation speed difference between two rotating bodies connected by engaging elements establishing the intermediate gear position is regarded as a speed difference reducing element, the control device executes a pre-engaging process for generating a torque capacity in the speed difference reducing element while the shifting control is being executed and before establishing the intermediate gear position.

A control device executes, when a jump-down shifting is executed, shifting control in which, after engaging elements establishing a pre-shifting gear position are released, an intermediate gear position that is a gear position between the pre-shifting gear position and a post-shifting gear position is established, and after the intermediate gear position is established, the post-shifting gear position is established. When an engaging element able to reduce a rotation speed difference between two rotating bodies connected by engaging elements establishing the intermediate gear position is regarded as a speed difference reducing element, the control device executes a pre-engaging process for generating a torque capacity in the speed difference reducing element while the shifting control is being executed and before establishing the intermediate gear position.

When starting a skip downshift, a controller for an automatic transmission disengages two or more engagement elements that are in an engaged state. The disengaging two or more engagement elements includes setting a first engagement element, which is one of the two or more engagement elements that are disengaged and is used to form an intermediate gear stage having a lower transmission ratio than a post-shifting gear stage, to an engagement preparation state that maintains a state immediately before the engaged state. Subsequently, the controller engages a second engagement element, which is used to form both the intermediate gear stage and the post-shifting gear stage, and temporarily increases engagement pressure of the first engagement element. The controller disengages the first engagement element and engages a third engagement element, which is used to form the post-shifting gear stage, to form the post-shifting gear stage.

When starting a skip downshift, a controller for an automatic transmission disengages two or more engagement elements that are in an engaged state. The disengaging two or more engagement elements includes setting a first engagement element, which is one of the two or more engagement elements that are disengaged and is used to form an intermediate gear stage having a lower transmission ratio than a post-shifting gear stage, to an engagement preparation state that maintains a state immediately before the engaged state. Subsequently, the controller engages a second engagement element, which is used to form both the intermediate gear stage and the post-shifting gear stage, and temporarily increases engagement pressure of the first engagement element. The controller disengages the first engagement element and engages a third engagement element, which is used to form the post-shifting gear stage, to form the post-shifting gear stage.

When a power-on downshift via an intermediate shift stage accompanied by input switching control is required and a predetermined shift stage is a shift stage lower than the intermediate shift stage, an electronic control unit performs torque phase control in a torque phase control time shorter than the torque phase control time that is set when the predetermined shift stage is a shift stage higher than the intermediate shift stage. Accordingly, it is possible to complete disengagement of a disengagement-side element early and to suppress a rapid increase of an input shaft rotation speed due to a clutch torque remaining.

When a power-on downshift via an intermediate shift stage accompanied by input switching control is required and a predetermined shift stage is a shift stage lower than the intermediate shift stage, an electronic control unit performs torque phase control in a torque phase control time shorter than the torque phase control time that is set when the predetermined shift stage is a shift stage higher than the intermediate shift stage. Accordingly, it is possible to complete disengagement of a disengagement-side element early and to suppress a rapid increase of an input shaft rotation speed due to a clutch torque remaining.

A gear train includes at least four gears sequentially engaged, multiple links configured to support the rotation shafts of the gears, and pins configured to fix the rotation shafts of the gears to the link, wherein the pins are installed such that, among the rotation shafts of the gears, two non-adjacent rotation shafts have both ends fixed to the link and one of adjacent rotation shafts has only one end fixed to the link.

A power transfer device that includes an automatic transmission that includes a plurality of engagement elements and a speed change gear mechanism capable of establishing a multiplicity of shift speeds by changing a power transfer path by engaging or disengaging the engagement elements; and a control device that is configured to control the automatic transmission.