Door hinge

A door hinge comprising:

• a fixed board fixed to a door frame;
• a cover housing fitted to the upper end of the fixed board;
• an operation frame fixed to a door;
• an operation cam member rotatably disposed inside the cover housing and axially coupled to the operation frame fixed to the door by means of a shaft, so that the operation cam member rotates around the shaft according to the rotating operation of the operation frame;
• a link coupled eccentrically to one side of the operation cam member by means of a second pin and linearly moving according to the rotating operation of the operation cam member;
• a slider coupled to the link by means of a first pin and moving horizontally in forward and backward directions according to the linear movements of the link in the state of being disposed inside the cover housing;
• and
• a spring fitted to the outer circumferential surface of the slider and compressed according to the horizontal movements of the slider to elastically support the closing operation of the door.