Locking device for opening and closing lid

A locking device comprising:

• a lid supported to be openable and closable by a spindle at one end portion thereof and slidably attached to one side surface of a main body case in a direction orthogonal to a length direction of the spindle;
• a pair of unlocking knobs slidably arranged along a front surface of the lid;
• and
• a locking portion formed on a main body case side and configured to set the lid in a locked state by locking a free end portion side of the lid by sliding the lid in one direction in a state where the lid is closed, wherein
• by sliding the pair of unlocking knobs in the locked state of the lid, a sliding operation of the lid in another direction is enabled to unlock the lid,
• on a back side of each of the pair of unlocking knobs in a state where the lid is closed, a knob guide provided with a prism-shaped protrusion is arranged on the main body case side,
• a projection pin is formed so as to project from a back surface of each of the pair of unlocking knobs, and a side surface of the projection pin of each of the pair of unlocking knobs is configured to position along any one of two orthogonal side surfaces of the prism-shaped protrusion formed in each of the knob guides, and
• the sliding operation of the lid is enabled when each of the projection pins is positioned along a first side surface of the prism-shaped protrusion, and the sliding operation is disabled when each of the projection pins is positioned along a second side surface of the prism-shaped protrusion.