Application principle of expansion screw application scope of expansion screw
expansion screw is composed of screw, expansion pipe and other components. The tail of the screw is conical, and the inner diameter of the cone is larger than the inner diameter of the expansion pipe. When the nut is tightened, the screw moves outward, and the conical part moves through the axial movement of the thread, thus forming a great positive pressure on the outer peripheral surface of the expansion pipe
bolt composite cable support, and the angle of the cone is very small, Thus, friction self-locking is formed between the wall, expansion pipe and cone, so as to achieve the fixing effect. For example, Sanfeng composite cable support is fixed by friction self-locking between the wall, expansion pipe and cone
scope of use of expansion screws
☆ expansion screws are flat due to small drilling, large tension and exposure after use. If not used, they can be removed at will to keep the wall flat. They have significant advantages and are widely used in various decoration occasions:
☆ fastening air conditioners, water heaters, range hoods, etc.
☆ fixing frameless balcony windows, anti-theft doors and windows, kitchens Bathroom components, etc.
☆ ceiling screw fixation (combined with casing and cone cap)
☆ other occasions that need to be fixed
detection of screwed high-strength bolt connection pairs
with the rapid development of society, the friction type connection of high-strength bolt connection pairs has been widely used in long-span structures, plant structures and bridges until now. It is also widely used in high-rise building frames and other related steel structures that are convenient for specimen clamping. The use of high-strength bolts for construction has the advantages of simple and convenient construction, reasonable stress and fatigue resistance, and the rapid development of China's extruder market, which is safe and reliable. In order to ensure the construction quality of high-strength bolt connection project, engineers and technicians must do a good job in the mobilization inspection of high-strength bolts and the control of quality inspection in the construction process with a high heart. And implement quality assurance measures
when tightening high-strength bolts, electric wrenches and constant torque ring wrenches need to be used, and the torsion axis instrument is used to calibrate. The dial wrench used for inspection shall be calibrated by hanging weight method. At this time, the torque error shall not be greater than 1% of its applied torque. Each electric wrench, ring wrench and dial wrench should be checked and calibrated by a specially assigned person, and a resume should be established, and a detailed registration should be made
the research of high strength and low temperature polycrystalline silicon (LTPs), AMOLED and in cell and on cell embedded touch screens was carried out. The quality inspection of bolts was in the charge of a specially assigned person. The tightening of high-strength bolts made on the same day should be checked and completed on the same day, and the construction records should be made, the more detailed the better. This is the initial tightening. Wait about four hours after the initial tightening and check the final tightening torque within 24 hours, It is required to rectify the fees charged by enterprises involved in violation of regulations in the liquidation of the 48th small enterprise to reduce the burden of enterprises "The clearing and rectification of the enterprise related charges is to complete the inspection of the final tightening torque within the time of reducing the burden of the enterprise. The technicians should use a small hammer weighing about 0.3 kg to knock one side of the nut after the initial tightening, and use their fingers to press and hold the other side of the opposite side of the nut for inspection. If high-strength bolts are found to vibrate greatly, they are considered to be unqualified products. At this time, the initial tightening inspection should be carried out again. The initial tightening inspection is carried out by Self inspection of bolt tightening team
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