The working principle of the door closer is as follows: when the door is opened, the door body drives the connecting rod to act, makes the transmission gear rotate, and drives the rack plunger to move to the right. As the plunger moves to the right, the spring is compressed and the hydraulic oil in the right chamber is also pressurized. The check valve ball on the left side of the plunger is opened under the action of oil pressure, and the hydraulic oil in the right chamber flows to the left chamber through the check 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 connecting rod to rotate, so that the door is closed.

The factors that should be considered in selecting the door closer are: the width of the door, the frequency of opening the door, the use requirements and the use environment, etc. The width of the door is the main factor in selecting the model of the door closer. Generally, if the weight of the door is small, the model with smaller force shall be selected, and vice versa. The door opening frequency is a factor closely related to product quality. For frequently used occasions, the product should have good sealing performance and long service life.

What are the requirements for door closer of Dalian marine parts

1. corrosion resistance: according to en standard, the corrosion resistance requirements of conventional door closers are higher than grade 4 (passing the 240 hour salt spray test), while for marine door closers, the corrosion resistance needs to be significantly improved to grade 5 (passing the 480 hour salt spray test) or higher than the 960 hour salt spray test.

2. anti tilt: the closing function of the door closer needs to adapt to the bumpy and inclined state during the ship running. As for the conventional door closer, it can hardly meet the inclination test under the ship inclination of 2-4 °. Therefore, it is necessary to select the door closer that meets the professional purpose of the shipbuilding industry.

3. considering that the place of use is offshore, the wind / air pressure will also act on the door leaf to increase the force for the normal closing of the door leaf and door closer. Therefore, 1-2 force levels shall be added for the selection of marine door closer according to the actual situation.

Modern hydraulic door closer (hereinafter referred to as door closer) began with a patent registered by Americans in the early 20th century. It is different from the traditional door closer. It achieves the cushioning effect by throttling the liquid in the door closer. The core of the design idea of the hydraulic door closer is to realize the control of the door closing process, so that the various functional indicators of the door closing process can be adjusted according to the needs of people.

With its compact and compact overall design, it can be almost seamlessly embedded in wooden or metal doors or door frames. After the door is closed, the door closer can not be seen from the inside and outside, creating a delicate and concise space, making the overall appearance more perfect and achieving seamless connection.