Driving-state switching device equipped with synchronizing mechanism

A driving state switching unit with a synchro-mechanism, comprising:

• a first gear and a second gear coaxially disposed;
• a gear connecting member axially movable so that the first gear and the second gear can be connected;
• a synchro-mechanism interposed between the first gear and the second gear;
• an electric actuator for moving the gear connection member;
• control means for controlling a supply current to the electric actuator;
• and
• judgement means for judging synchronization of the synchro-mechanism, based on a change in the supply current value to the electric actuator,
• equipped in a part-time four-wheel-drive vehicle and constructed as a driving state switching unit that performs switching of a driving state between a 2-wheel-drive state and a 4-wheel-drive state;
• and
• further comprising a switching mechanism for switching the 2-wheel-drive state and the 4-wheel-drive state by switching an engagement relationship between said plurality of gears through the synchro-mechanism;
• wherein the judgement means judges synchronization of the synchro-mechanism, based on a change in the supply current to the electric actuator, after switching a driving state from the 2-wheel-drive state to the 4-wheel-drive state has been started by the switching mechanism.

A driving state switching unit with a synchro-mechanism, comprising:

• a first gear and a second gear coaxially disposed;
• a gear connecting member axially movable so that the first gear and the second gear can be connected;
• a synchro-mechanism interposed between the first gear and the second gear;
• an electric actuator for moving the gear connection member;
• control means for controlling a supply current to the electric actuator;
• and
• judgement means for judging synchronization of the synchro-mechanism, based on a change in the supply current value to the electric actuator,
• constructed as a speed change stage switching unit for switching a stage of a speed change according to driver's shift manipulation;
• and
• further comprising a switching mechanism for switching a stage of a speed change corresponding to a shift position selected by a driver, by switching an engagement relationship between said plurality of gears through the synchro-mechanism;
• wherein the judgement means judges synchronization of the synchro-mechanism, based on a change in the supply current to the electric actuator, after switching of the speed change stage has been started by the switching mechanism,
• wherein the control means controls said supply current by setting a current indicating value to the electric actuator, and when the judgement means judges that the synchro-mechanism is in a synchronous state sets the current indicating value to a predetermined value corresponding to a speed change ratio of said speed change stages.