| 摘要 |
The present invention relates to a door closing device which can simply be installed in a door frame without damage to wall portions around the door frame, thereby having low installation costs; reduces a number of components and has a simple structure, thereby drastically saving manufacturing costs and being easily used while having excellent durability; and moreover, uses an independent alarm type sensor having low manufacturing costs and being easily repaired as a fire sensing unit, thereby largely enhancing reliability for a fire sensing function of the fire sensing unit. The present invention comprises: a support unit; a fixated unit provided on a rear side of the support unit to be fixated to the door frame; a door opening maintenance unit provided on a front side of the door, and touching the door in an opened state provided on an inner side of the door frame to maintain an opened state of the door; and a control unit releasing the door opening maintenance state of the door opening maintenance unit to control the door opening maintenance unit to close the door. |
