What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Hydraulic wrench or pulling method Use hydraulic torque wrench or puller to fasten large screws, which saves effort and has high precision. However, hydraulic tools are expensive, screws of different sizes need to be equipped with different wrenches, and now the hydraulic pullers in the world are generally only M160×6. If the screws are too large, special specifications or very few in number, it is extremely uneconomical to equip them with hydraulic tightening tools.
1. First remove the sludge on the surface of the broken head of the broken screw, use the center gun to kill the center gun of the section, and then use an electric drill to install a drill bit with a diameter of 6-8 mm to drill the hole in the center of the section, pay attention to the hole must be drilled through. After the hole is drilled through, remove the small drill bit and replace it with a drill bit with a diameter of 16 mm, and continue to expand and drill through the hole of the broken bolt. 2. Take a welding rod with a diameter of less than 3.2 mm and use a medium and small current to carry out surfacing welding from the inside to the outside in the hole of the broken bolt. Take half of the entire length of the broken bolt at the beginning of the surfacing welding. When starting the surfacing welding, the arc should not be too long. In order to avoid burning through the outer wall of the broken bolt, surfacing to the upper end face of the broken bolt, and then continue surfacing to weld a cylinder with a diameter of 14-16 mm and a height of 8-10 mm. 3. After the surfacing is completed, hammer the end face with a hammer to make the broken bolt vibrate along its axial direction. Due to the heat generated by the previous arc and the subsequent cooling plus the vibration at this time, the broken bolt and the thread of the body will be loose in between. 4. Carefully observe, when it is found that a small amount of rust leaks from the fracture after the knock, take the M18 nut and put it on the surfacing column head and weld the two together. 5. After welding, use a torx wrench to cover the nut while it is still hot, and twist it back and forth, or tap the end face of the nut with a small hand hammer while twisting back and forth, so that the broken bolt can be taken out. 6. After taking out the broken bolt, use a suitable tap to process the thread in the frame to remove rust and other debris in the hole.
High-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.
The tooling for screw standard parts provided by Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. mainly solves the problems of low manual operation matching efficiency, wrong specifications of screw standard parts, and easy falling of screw standard parts into the product when assembling screws in the prior art. . The specific technical solutions of Guangdong Yueluo Hardware Industry Co., Ltd. are as follows. The screw standard parts supporting tooling includes a stud sleeve hole plate, a gasket sleeve hole plate and a nut sleeve hole plate with matching structure; the stud sleeve hole plate There is at least one stud hole matching with the assembled stud structure, at least one gasket hole matching with the assembled gasket structure is arranged on the gasket sleeve hole plate, and the nut sleeve hole plate is provided with at least one gasket hole matching with the assembled gasket structure. At least one nut hole matched with the assembled nut structure; the number of stud holes, gasket holes and nut holes are equal. The above-mentioned stud sleeve hole plate is provided with a positioning device, and the gasket sleeve hole plate is provided with a matching positioning hole; or the gasket sleeve hole plate is provided with a positioning device, and the stud sleeve hole plate is provided with a matching positioning hole. The above stud holes are through holes; the nut holes are blind holes. Forty to one hundred and fifty stud holes are arranged on the stud sleeve hole plate. The above-mentioned positioning device is a positioning plate and/or a positioning column. The advantage of Guangdong Yueluo Hardware Industry Co., Ltd. is that the matching tooling for screw standard parts improves the matching quality of screw standard parts, effectively prevents screw standard parts from falling into the product easily and screw specifications are wrong; it simplifies the matching difficulty of screw standard parts and improves assembly efficiency. . The screw standard parts supporting tooling can be processed differently according to different screw standard parts specifications, and the applicability is very wide.
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