Hinge device

The utility model provides a hinge device which is suitable for a machine shell and comprises a first hinge, a locking piece and a shifting button. The first hinge is located in the machine shell and comprises a first contact face. The axis of the first hinge is parallel to the first axis. The locking piece is located in the machine shell and comprises a second contact face and a first inclined face which are opposite, and the locking piece makes contact with the first contact face through the second contact face. The shifting button is partially located outside the machine shell and comprises a second inclined face. The second inclined plane is contacted with the first inclined plane, and the shifting button is movably arranged on the machine shell along the second axis. When the shifting button moves along the second axis, the second inclined plane pushes the first inclined plane to enable the locking piece to move relative to the first hinge along the first axis, and then the second contact surface is in c