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: 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: A method of manufacturing a valve sleeve is disclosed which is adapted to construct an oil rotary valve together with a valve rotor, and a valve sleeve of a configuration which is suitably formed by carrying out the method is also disclosed. The valve sleeve has an axially extending groove in its inner surface, and the bottom surface of the groove has a portion which is disposed at an angle with respect to the axis. The method of manufacturing comprises shaping a cylindrical member having an inner and an outer diameter, both of which are greater than those of a valve sleeve to be manufactured, inserting a punch into the material, and applying a compression to the material from the radially outside thereof to cause the internal surface of the material to bear against the punch.

Abstract: A method of manufacturing a valve sleeve is disclosed which is adapted to construct an oil rotary valve together with a valve rotor, and a valve sleeve of a configuration which is suitably formed by carrying out the method is also disclosed. The valve sleeve has an axially extending groove in its inner surface, and the bottom surface of the groove has a portion which is disposed at an angle with respect to the axis. The method of manufacturing comprises shaping a cylindrical member having an inner and an outer diameter, both of which are greater than those of a valve sleeve to be manufactured, inserting a punch into the material, and applying a compression to the material from the radially outside thereof to cause the internal surface of the material to bear against the punch.

Abstract: A method of manufacturing a valve sleeve which is combined with a valve rotor to form a hydraulic rotary valve comprises a first step of expanding one end of a cylindrical member, a second step of forming a plurality of axial grooves in the internal surface of the cylindrical member while leaving its opposite ends intact, and a third step of restoring the expanded portion to its original diameter which it assumes before the expanding step.