The door closer is a spring-like hydraulic device on the door head. When the door is opened, it can be compressed and released to automatically close the door. It acts like a spring door and can ensure that the door is opened accurately and timely to the initial position. .
The significance of the door closer is not only to automatically close the door, but also to protect the door frame and door body (smooth closing). More importantly, the door closer has become an important part of the intelligent management of modern buildings.
Door closers are mainly used in commercial and public buildings, but they are also used at home. They have many uses, the most important of which is to make the door close by itself to limit the spread of fire and ventilation in the building.
The basic components of hydraulic door closers are support guides, transmission gears, return springs, one-way valves, rack plungers, throttle valve cores and shells, end caps, sealing rings and connecting rods. The shell and the connecting rod play the role of fixing the door closer and connecting the door leaf and the door frame.
The working principle of the door closer is: when the door is opened, the door body drives the connecting rod to move, and rotates the transmission gear, driving the rack plunger to move to the right. When the plunger moves to the right, the spring is compressed, and the hydraulic oil in the right cavity is also compressed. The one-way valve ball on the left side of the plunger is opened under the action of oil pressure, and the hydraulic oil in the right cavity flows into the left cavity through the one-way valve. When the door opening process is completed, as the spring is compressed during the opening process, the accumulated elastic potential energy is released, pushing the plunger to the left, driving the transmission gear and the door closer link to rotate, so that the door is closed.
During the spring release process, because the hydraulic oil in the left cavity of the door closer is compressed and the one-way valve is closed, the hydraulic oil can only flow out through the gap between the housing and the plunger, and pass through the small hole on the plunger and 2 The flow path equipped with the throttle valve core flows back to the right cavity. Therefore, the hydraulic oil constitutes resistance to the release of the spring, that is, the effect of buffering is achieved by throttling, and the speed of closing the door is controlled. The throttle valve on the valve body can be adjusted to control the variable closing speed of different stroke sections. Although the structure and size of door closers produced by different manufacturers are different, the principles are the same.
The types of door closers can be divided into: exterior and built-in door top door closers, built-in door middle door closers, door bottom door closers, vertical door closers (built-in vertical door closers) and Other types of door closers.