Abstract: A transmission controller includes a rotatable shaft that controls engagement and disengagement of a variable speed clutch. An actuator, such as an electric motor, drives the shaft. The shaft is rotated alternately in the normal and reverse directions by supplying a low level current to such an extent that a clutch transfer mechanism is not operated by the rotation. Rotation stop positions are detected. A play area between the rotation stop positions is calculated and can be used to correct for manufacturing inaccuracies or for wear occurring over time.

Abstract: An electronically controlled transmission in which a single drive motor is used to drive a shift shaft, in which shift shock is reduced during continuous running. The transmission has a shift shaft, an actuator, a gear box and a control portion. The actuator causes the shift shaft to rotate. The gear box includes a gear shift mechanism, a clutch mechanism, and a crank case that houses the gear shift mechanism and the clutch mechanism. The gear shift mechanism is activated in association with rotation of the shift shaft. The clutch mechanism connects and disconnects transmission of power to the gear shift mechanism from the engine in association with rotation of the shift shaft. The control portion controls the actuator based on the temperature of the gear box.

Abstract: A straddle vehicle comprises a single actuator that controls clutch engagement as well as gear shifting. The actuator can be connected to the clutch and the shiftable transmission with a rotating shaft. When an engine speed reaches or exceeds a preset value during an up-shift operation, an ECU or other controller reduces the engine output to facilitate a smooth gear shift.

Abstract: A shift control device in which a number of times that an angle change amount per a defined time period is successively equal to or less than a determined value is calculated, when a rotation angle of a shift shaft is equal to or more than a threshold value. In addition, an abutting state determination is performed that determines whether the number of times is equal to or above a threshold value, and if it is determined that there is an abutting state (namely, the shift shaft has reached an actual mechanical maximum rotation angle), processing shifts to an engagement process of a shift clutch.

Abstract: A shift control device is provided for reducing a shock generated at a clutch engagement moment in a gearshift operation in a straddle type vehicle having a shift control device that makes the clutch operation and the gearshift operation using the power of an actuator. The actuator is controlled based upon a rotational position and a speed of a shift shaft. When the rotational position of the shift shaft is located between a first position and a second position, the shift shaft is rotated at a speed slower than a rotational speed at which the shift shaft is rotated before reaching the first position to engage a gearshift clutch at a low speed. The first position and the second position are set in such a manner that the gearshift clutch is in a halfway engaged state when the shift shaft is located at a rotational position between the first position and the second position.

Abstract: A gear change control device for improving the stability of shift changes in a straddle-type vehicle. In response to an operation of a shift up switch or a shift down switch, the target angular position (?max(up), ?max(down), ?meet(up), ?meet(down), ?on(up), ?on(down)) and the rotational speed (vmax(up), vmax(down), vo(up), vo(down), v12(up)-v34(up), v21(down)-v43(down)) of a shift shaft are set based on a gear change command input signal inputted from the shift up switch or the shift down switch to a CPU. The shift shaft is rotationally driven at the set rotational speed until the set target rotational position is reached.

Abstract: An electronically controlled transmission in which a single drive motor is used to drive a shift shaft, in which shift shock is reduced during continuous running. The transmission has a shift shaft, an actuator, a gear box and a control portion. The actuator causes the shift shaft to rotate. The gear box includes a gear shift mechanism, a clutch mechanism, and a crank case that houses the gear shift mechanism and the clutch mechanism. The gear shift mechanism is activated in association with rotation of the shift shaft. The clutch mechanism connects and disconnects transmission of power to the gear shift mechanism from the engine in association with rotation of the shift shaft. The control portion controls the actuator based on the temperature of the gear box.

Abstract: A straddle vehicle comprises a single actuator that controls clutch engagement as well as gear shifting. The actuator can be connected to the clutch and the shiftable transmission with a rotating shaft. When an engine speed reaches or exceeds a preset value during an up-shift operation, an ECU or other controller reduces the engine output to facilitate a smooth gear shift.

Abstract: A shift control device in which a number of times that an angle change amount per a defined time period is successively equal to or less than a determined value is calculated, when a rotation angle of a shift shaft is equal to or more than a threshold value. In addition, an abutting state determination is performed that determines whether the number of times is equal to or above a threshold value, and if it is determined that there is an abutting state (namely, the shift shaft has reached an actual mechanical maximum rotation angle), processing shifts to an engagement process of a shift clutch.

Abstract: A transmission controller includes a rotatable shaft that controls engagement and disengagement of a variable speed clutch. An actuator, such as an electric motor, drives the shaft. The shaft is rotated alternately in the normal and reverse directions by supplying a low level current to such an extent that a clutch transfer mechanism is not operated by the rotation. Rotation stop positions are detected. A play area between the rotation stop positions is calculated and can be used to correct for manufacturing inaccuracies or for wear occurring over time.

Abstract: A shift control device is provided for reducing a shock generated at a clutch engagement moment in a gearshift operation in a straddle type vehicle having a shift control device that makes the clutch operation and the gearshift operation using the power of an actuator. The actuator is controlled based upon a rotational position and a speed of a shift shaft. When the rotational position of the shift shaft is located between a first position and a second position, the shift shaft is rotated at a speed slower than a rotational speed at which the shift shaft is rotated before reaching the first position to engage a gearshift clutch at a low speed. The first position and the second position are set in such a manner that the gearshift clutch is in a halfway engaged state when the shift shaft is located at a rotational position between the first position and the second position.

Abstract: A gear change control device for improving the stability of shift changes in a straddle-type vehicle. In response to an operation of a shift up switch or a shift down switch, the target angular position (?max(up), ?max(down), ?meet(up), ?meet(down), ?on(up), ?on(down)) and the rotational speed (vmax(up), vmax(down), vo(up), vo(down), v12(up)-v34(up), v21(down)-v43(down)) of a shift shaft are set based on a gear change command input signal inputted from the shift up switch or the shift down switch to a CPU. The shift shaft is rotationally driven at the set rotational speed until the set target rotational position is reached.