Shift device of transmission

A shift device of a transmission, comprising:

• a cylindrical or columnar shift cam that is formed, at an outer circumferential surface of the shift cam, with a cam groove for operating a shift fork;
• a drive plate that oscillates by rotation of a shift pedal shaft;
• a shift cam plate that is fixed to one end portion of the shift cam and rotates the shift cam according to the oscillation of the drive plate;
• a shift cam sensor that detects a rotation angle of the shift cam;
• and
• a transmission shaft that transmits the rotation of the shift cam to the shift cam sensor, wherein
• an insertion hole is provided in a position corresponding to a rotation axis of the shift cam at the one end portion of the shift cam,
• a through hole penetrating the shift cam plate is provided in the shift cam plate,
• the transmission shaft is disposed coaxially with the shift cam, one end portion of the transmission shaft is connected to or opposed to the shift cam sensor, and an other end portion of the transmission shaft penetrates the through hole and is fixed to the shift cam in a state of being press-fitted into the insertion hole,
• a diameter of the transmission shaft is larger at the one end portion of the transmission shaft than at the other end portion of the transmission shaft and than at an intermediate portion, connecting the one end portion and the other end portion, of the transmission shaft;
• and a part of the one end portion shaft of the transmission shaft is overlapped with the drive plate as viewed in an axial direction of the transmission shaft, and
• the one end portion of the transmission shaft is provided with an engagement groove that is engaged with an engagement projection piece of the shift cam sensor, and the engagement groove is provided at a portion on an outer circumferential surface of the one end portion of the transmission shaft from an outer edge of an end face of the one end portion of the transmission shaft.