Almost all automatic door closers have two levels of adjustable functions: closing speed and locking speed. The locking speed is adjusted according to the hardness of the locking tongue to lock the movable leaf without generating unnecessary impact on the door frame. The adjustment of the whole closing speed is not affected by the locking speed.
Opening resistance is a very important function for building exterior doors. The automatic door closer should not only prevent the excessive opening of the movable fan due to the large thrust of people, but also prevent the damage of the door body caused by the excessive opening of the movable fan due to strong wind when opening. Generally speaking, only the high-grade door closer can have this function. The lagging door closing is a special function, which aims to make the movable fan stay in the open position for a period of time and then close the door. This function is very important when there are children and old people passing through. Adjustable door closing force is the sign of high-grade automatic door closer, which can accurately adjust the level of door closing force. The door closing force is usually the specific performance of a certain type of door closer, but sometimes the door closing force will also change. For example, when the wind is strong in winter, the outer door may need a large closing force, and when the wind is small in summer, the closing force is small, making it easier for people to open the movable fan.