Neutral control for vehicular automatic transmission
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsAkio Sugawara, Masaru Morise, Hideki Miyata, Yuji Yasuda, Hiroaki Takeuchi
Life of this patent
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Abstract
A friction apply device, from among each pair of friction apply devices that are applied to achieve a speed from first speed to fourth speed, that is to be placed in a slipping state is selected based on a heat load when a neutral control is executed. As a result, it is possible to continue to execute the neutral control without the durability of the friction apply device being impaired by the heat load, for example, thereby increasing a fuel efficiency effect and the like achieved by the neutral control.
Claims10
An automatic shifting system for a vehicle, comprising:
- an automatic transmission which is provided with a plurality of engaging elements including a first engaging element and a second engaging element, and which achieves a first running speed by applying the first engaging element and the second engaging element;
- and
- a controller that executes a neutral control that interrupts the transmission of power by placing at least one of the applied first and second engaging elements in a released or slipping state when the automatic transmission is in a predetermined operating state in the first running speed,
- wherein the controller is adapted to select, when the neutral control is executed, one of the first and second engaging elements based on a predetermined condition and place the selected first or second engaging element in the released or slipping state.
A method for executing a neutral control in an automatic transmission for a vehicle which is provided with a plurality of engaging elements, comprising:
- achieving a first running speed by applying a first engaging element and a second engaging element which are included in the plurality of engaging elements;
- and
- executing the neutral control by selecting one of the first and second engaging elements based on a predetermined condition, placing the selected first or second engaging element in a released or slipping state, and interrupting the transmission of power when the automatic transmission is in a predetermined operating state in the first running speed.
Dependencies are inferred from the claim text.