Patent ID: 8393992

Claim:
A vehicle differential gear comprising: a ring gear engaged with a pinion gear provided on a propeller shaft; a differential case attached to a side surface of the ring gear, forming a differential mechanism chamber; a differential mechanism accommodated in the differential case; a side gear engaged with the differential mechanism for transmitting a driving force from the propeller shaft via left and right driven shafts to vehicle wheels; a lock pin, inserted through the differential case into a pin hole formed in the side gear to stop a differential operation of the differential mechanism to set a differential lock status; an operation member for operating the lock pin; a boss integrally formed to insert the driven shaft through the ring gear or the differential case; an annular member provided in the boss, said annular member being slidable along an axial direction of the boss, and provided with the lock pin therein; wherein a locking piece that rotates along with rotation of the ring gear or the differential case is attached to the ring gear or the differential case; and a contact piece contactable with the locking piece is formed in the operation member; wherein when a number of revolutions of the ring gear or the differential case becomes a predetermined number of revolutions, the locking piece moves to a position facing the contact piece to regulate actuation of the operation member.