Service HotlineHigh-strength bolt connection has the advantages of simple construction, good mechanical performance, disassembly and replacement, fatigue resistance, and no loosening under dynamic load. It is a promising connection method. High-strength bolts use a special wrench to tighten the nut, so that the bolt generates a huge and controlled pre-tension. Under the action of pre-pressure, a large frictional force will be generated along the surface of the connected parts. Obviously, as long as the axial force is less than this frictional force, the components will not slip and the connection will not be damaged. This is the high-strength bolt connection. principle. High-strength bolted connections rely on the friction between the contact surfaces of the connectors to prevent them from sliding each other. In order to make the contact surfaces have sufficient friction, it is necessary to increase the clamping force of the components and increase the friction coefficient of the contact surfaces of the components. The clamping force between the components is achieved by applying pretension to the bolts, so the bolts must be made of high-strength steel, which is why it is called high-strength bolted connections. In high-strength bolted connections, the friction coefficient has a great influence on the bearing capacity. Tests show that the coefficient of friction is mainly affected by the form of the contact surface and the material of the components. In order to increase the friction coefficient of the contact surface, methods such as sandblasting and wire brush cleaning are often used to treat the contact surface of the components within the connection range during construction.
Fasteners are also divided into different types according to different uses, and new types of fasteners are developed according to the needs of special environments to meet the needs of all walks of life. The gasket combination bolt is a common fastening bolt. The combination gasket protects the surface of the connected parts from scratches, disperses the pressure on the connected parts, and has a sealing and anti-loosening effect. It is widely used. With the continuous improvement of requirements, the new zinc-aluminum coating surface treatment has gradually become the mainstream surface treatment process because it meets the environmental protection requirements, the surface is beautiful, and the corrosion resistance strength is higher than that of the zinc-nickel surface treatment.
(1) The surface rust, oil stains, burrs on the wall of the bolt holes, welding flashes, etc. should be cleaned up. (2) After the contact friction surface is treated, the specified anti-scratch coefficient requirements must be met. The high-strength bolts used should have matching nuts and washers, which should be used in accordance with the matching and should not be interchanged. (3) When the friction surface of the treated component is installed, it is not allowed to be stained with oil, soil and other sundries. (4) The friction surface of the module should be kept dry during installation and should not be operated in the rain. (5) Strictly check and correct the deformation of the connected steel plates before installation. (6) It is forbidden to hammer into the bolt during installation to prevent damage to the bolt thread. (7) The electric wrench, which is regularly tested during use, ensures the accuracy of the torque and operates in the correct tightening sequence. Main safety technical measures (1) The size of the wrench of the adjustable wrench should be consistent with the size of the nut, and the sleeve should not be added to the small wrench. A dead wrench should be used for high-altitude work. For example, when using an adjustable wrench, use a rope to fasten it, and people should fasten their seat belts. (2) When assembling the connecting bolts of steel components, it is strictly forbidden to insert your hands into the connecting surface or touch the screw holes. When picking and placing the bolster, your fingers should be placed on both sides of the bolster.
The elastic cylindrical pin, also known as the spring pin, is a headless hollow cylindrical body, which is slotted in the axial direction and chamfered at both ends. It is used for positioning, connection and fixation between parts. The outer diameter of the spring pin is usually slightly larger than the mounting hole. The deformation force generated by the elastic cylindrical pin to be restored to its original state by extrusion ensures the clamping effect of the elastic cylindrical pin. But just because of its clamping effect, it will play a big obstacle to the disassembly of the elastic cylindrical pin. When in use, the open end is extended out of the through hole on the pin shaft, and the open end is flared and separated to prevent the elastic cylindrical pin from sliding off the pin shaft to realize the function of preventing backlash. At present, the disassembly method of the elastic cylindrical pin usually uses a punching machine to remove the cylindrical pin, which easily destroys the equipment installed on the cylindrical pin, and the disassembled elastic cylindrical pin cannot be used again due to damage. One method is to insert the mounting pin with the clearance fit of the mandrel, punch the pin behind the mandrel to clamp the bottom of the cylindrical pin, and then pull out the cylindrical pin, which can only be used when the elastic mounting pin is installed in the through hole, and because it is necessary Applying force to the mandrel increases the difficulty of disassembly and increases the work intensity of the installer. Three methods are done by the installer using two needle nose pliers. Specifically, first use needle-nose pliers to clamp the ends of both sides of the elastic cylindrical pin, and then apply an inward force to the needle-nose pliers, so that both sides of the elastic cylindrical pin rotate in the same direction until the opening becomes smaller, and then Pull it out to remove it successfully. The defects of these existing methods are obvious. The shape of the disassembled elastic cylindrical pin is either unusable or the deformation of the cylindrical pin after disassembly is not uniform, which seriously affects the performance of the elastic cylindrical pin, resulting in waste and increased cost; The method is purely manual work, and sometimes it takes several repetitions to remove the elastic cylindrical pin. Due to the different installation positions of the elastic cylindrical pin, it sometimes increases the difficulty of disassembly, and it is difficult to remove the needle-nose pliers effectively. The pliers are difficult to construct, and the elastic cylindrical pins are easily damaged. If there are too many elastic cylindrical pins to be disassembled, the existing methods are often difficult to meet the needs, which not only consumes a lot of time and physical strength of the installer, but also makes it difficult to ensure the quality.
The side wall of the bolt hole is threaded, and the top of the nut is provided with several flattening notches. According to the locking nut of the preferred embodiment of Guangdong Yueluo Hardware Industry Co., Ltd., the number of flattening notches is three. Due to the above features, the three flattening notches can be used as the focal point of the tightening tool, and the
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