c. Use and maintenance of door closers, repairs
Newly installed door closers are used for approximately one to ten days, and all screws should be inspected and retightened.
Use hydraulic oil recommended by the manufacturer. For cold areas, use low-condensation hydraulic oil.
The door closer should be inspected regularly after being put into use. The contents of the inspection are: whether the mounting screws are loose or missing, whether the connecting arm rubs against the door or the door frame, whether the door body is deformed or loosened, the buffering effect of closing the door, and the support guiding Whether the piece leaks oil, etc.
Usually the following problems occur after the door closer has been used for a while:
1) The mounting screws are loose or missing, resulting in the door closer not being in the correct mounting position and the connecting arm being damaged;
2) When the door closer is closed, the buffering effect is deteriorated, causing the door to collide with the door frame and the door body is deformed;
From the structure point of view, the door closer is a closed whole, and its quality is basically not seen from the appearance.
The most critical quality problem of the door closer is whether it leaks oil, because the door closer relies on the throttling of the fluid in its internal hydraulic system to control the closing process. The oil leakage means the failure of the hydraulic system, so the hydraulic system is The only criterion that determines the life of the door closer.
The most important cause of oil leakage is that the pinion support guide wears to increase the clearance, the seal wear causes the sealing effect to decrease, or the throttle spool rotates counterclockwise away from the valve body when adjusting the cushioning effect.
The reduction in the cushioning effect of the door closer is caused by the entry of air due to oil leakage or the increase in the fit (throttle) gap between the rack plunger guiding cylinder and the valve body. Therefore, the quality and accuracy of the material of the pinion and the support guide, heat treatment and machining are very important.
For a door closer with poor cushioning effect, simply adjusting the throttle spool for throttling cannot solve the problem at all. It is necessary to repair the method. If there is oil leakage at the support guide, remove the support guide and check the condition of the seal. If it is worn or aged, replace the seal. If the gap between the support guide and the pinion shaft is too large, the support guide is replaced. If the rack plunger is worn on the guide cylinder, the clearance between the valve body and the valve body is increased, resulting in a decrease in the throttling effect. The rack plunger can be removed and the surface is chrome-plated. In addition, in the case of ensuring the cushioning effect of the door closer, the use of a softer spring is also a method of reducing the impact force of the door to the door frame due to the deterioration of the cushioning effect.