There are many kinds of door and window hardware that affect the sealing performance of doors and windows. According to the sealing performance of doors and windows, it can be divided into two categories: multi lock point hardware and single lock point hardware. The effect of door and window hardware on air tightness of doors and windows should be paid enough attention by door and window enterprises.

After the doors and windows are locked, the lock points and the lock seats are firmly buckled together and cooperate with the hinge (hinge) or sliding brace to produce a strong sealing and pressing force, which makes the sealing strip elastic deformation, so as to provide sufficient sealing performance for doors and windows, and make the leaves and frames form an integral whole; Therefore, multi lock point hardware has many advantages to the sealing of doors and windows, which can greatly improve the sealing performance of doors and windows. However, the sealing performance of single locking point hardware is relatively poor. Because the single locking point can only provide single point locking at the open side of doors and windows, it can only produce 3 or 4 locking points when it is cooperated with hinge (hinge) or sliding brace, which makes four corners of doors and windows in unconstrained state. Therefore, the gap between two unconstrained angles and locking points seriously reduces the sealing performance of doors and windows.

Take the layout of the handle side lock point as an example: set the window width as B, the window height as h, and the window leaf bending stiffness e × I, which can be divided into three situations: single locking point, two locking point and three locking point (the distance between the lock point and the leaf edge is not less than 0.1 mm). According to the mechanical formula, the maximum deformation value of the handle side of the window sash in the sealing direction is given. Thus, it can be seen that the deformation of the door and window sash can be greatly reduced and the sealing performance can be improved by adopting the three locking points. Of course, under the condition of meeting the strength and sealing requirements, it is not suitable to use too many locking points, otherwise it will cause waste.

Similarly, most of the hinges used in doors and windows need to cut off the sealant strip at the hinge position in the process of use, and have you considered the impact on air tightness caused by the installation of hinge? In fact, the negative effect of gap penetration caused by cutting off the sealant strip on energy saving is basically ignored.