Door closer is a device used to control the automatic closing of door leaves, widely used in door control systems of various buildings. Its main functions and roles are as follows: Function: 1. Automatic closing of door leaf: The most basic function of a door closer is to enable the door leaf to automatically close after opening, thereby maintaining the enclosure and safety of the space. 2. Control closing speed: The door closer can control the closing speed of the door leaf by adjusting the hydraulic valve, ensuring smooth closing of the door leaf and avoiding noise or damage caused by closing too quickly. 3. Buffer function: The door closer provides a certain buffering force when the door leaf is about to close, preventing violent collision between the door leaf and the door frame, and protecting the door body and door frame from damage. 4. Door stopping function: Some door closers also have a door stopping function, which means that when the door leaf is opened to a certain angle, it can be fixed, making it convenient for personnel to enter and exit or for ventilation and other operations. 5. Fire prevention function: In the event of a fire, the door closer can quickly close the door leaf, prevent the spread of fire, and buy time for personnel evacuation. effect: 1. Improve safety: The door closer can ensure that the door leaf automatically closes when not needed, preventing unauthorized personnel from entering and improving the safety of the building. 2. Energy saving and environmental protection: Door closers help reduce the loss of energy such as air conditioning and heating, lower energy consumption, and achieve energy-saving and environmental protection effects. 3. Protecting the door body and door frame: The buffering function of the door closer can reduce the impact force between the door leaf and the door frame, extending the service life of the door body and door frame. 4. Improving user experience: The door closer enables the door leaf to close smoothly and slowly, avoiding noise and discomfort caused by sudden closure, enhancing the user experience. 5. Meet fire safety requirements: In public places and high-rise buildings, door closers are one of the important devices that meet fire safety requirements. They can quickly close door leaves in case of a fire, preventing the spread of the fire. In summary, door closers play an important role in building door control systems, and their functions and roles are of great significance for improving building safety, energy conservation, environmental protection, and user experience.