Abstract: An automatic-clutch control system of a transmission for a vehicle is arranged to calculate a deceleration of the vehicle when shifting is not being executed, when an automatic shift mode is being selected, when an idle switch is set at ON state, and when a brake switch is set at OFF state, and when the vehicle is being decelerated. Further, the automatic-clutch control system decreases an engagement force of the automatic clutch according to an increase of the deceleration and a decrease of a vehicle speed to vary the engagement state.

Abstract: A transmission system is comprised of a twin-clutch transmission which comprises a first clutch for selecting a first gear-ratio group and a second clutch for selecting a second gear-ratio group. A control unit for controlling the twin-clutch transmission is arranged to calculate an estimated engine revolution speed produced in the event that one of two gear ratios adjacent to the present gear ratio is selected by executing one of upshift and downshift, and to disengage one of the first and second clutches which is engaged to select the gear-ratio group including the other of the two gear ratios adjacent to the present gear ratio when the estimated engine revolution speed is out of a normal operation speed range.

Abstract: A control unit is provided for controlling a twin clutch mechanism which includes first and second automatic clutches respectively incorporated with first and second groups of gears. The control unit is configured to carry out establishing a condition wherein both the first and second automatic clutches are in their engaged conditions and wherein one of the first and second groups of gears is operated to select a certain speed gearing with the aid of a corresponding selection mechanism while leaving the other of the first and second groups of gears in a neutral condition with the aid of the other corresponding selection mechanism; and releasing the engaged condition of the automatic clutch incorporated with the other of the first and second groups of gears when the other of the first and second groups of gears is in a critical condition to induce a gear hit noise.

Abstract: A transmission system is comprised of a twin-clutch transmission which comprises a first clutch for selecting a first gear-ratio group and a second clutch for selecting a second gear-ratio group. A control unit for controlling the twin-clutch transmission is arranged to calculate an estimated engine revolution speed produced in the event that one of two gear ratios adjacent to the present gear ratio is selected by executing one of upshift and downshift, and to disengage one of the first and second clutches which is engaged to select the gear-ratio group including the other of the two gear ratios adjacent to the present gear ratio when the estimated engine revolution speed is out of a normal operation speed range.

Abstract: An automatic-clutch control system of a transmission for a vehicle is arranged to calculate a deceleration of the vehicle when shifting is not being executed, when an automatic shift mode is being selected, when an idle switch is set at ON state, and when a brake switch is set at OFF state, and when the vehicle is being decelerated. Further, the automatic-clutch control system decreases an engagement force of the automatic clutch according to an increase of the deceleration and a decrease of a vehicle speed to vary the engagement state.

Abstract: A control unit is provided for controlling a twin clutch mechanism which includes first and second automatic clutches respectively incorporated with first and second groups of gears. The control unit is configured to carry out establishing a condition wherein both the first and second automatic clutches are in their engaged conditions and wherein one of the first and second groups of gears is operated to select a certain speed gearing with the aid of a corresponding selection mechanism while leaving the other of the first and second groups of gears in a neutral condition with the aid of the other corresponding selection mechanism; and releasing the engaged condition of the automatic clutch incorporated with the other of the first and second groups of gears when the other of the first and second groups of gears is in a critical condition to induce a gear hit noise.

Abstract: A system and method for controlling an ignition timing for an internal combustion engine mounted in a vehicle are disclosed in which a limit value for the ignition timing value is provided so that a difference between a current ignition timing and a previous ignition timing is within the limit value and the limit value is set according to a magnitude of an engine acceleration. For example, when an abrupt engine acceleration occurs, the limit value is set to 15 degrees. When the engine is in a steady state (no abrupt acceleration from an idling condition), the limit value is set to four degrees. Therefore, no vehicle body shock occurs due to the abrupt change in an engine output torque caused by the abrupt change in the ignition timing and a response characteristic of a rise in the engine output torque during the abrupt acceleration can be assured.