At present, there are many kinds of smart terminals on the market. Due to the reduction of the overall volume of the smart terminal and the more compact internal parts, the nuts are generally made of injection-molded nuts. The traditional injection-molded nuts are directly fixed on the equipment. During the process, it is easy to loosen and fall off, which greatly reduces the service life of the injection nut and brings inconvenience to the use of the mobile terminal.
For a long time, the rivets used in general riveting, especially the ordinary rivets and bolts and other fasteners commonly used in steel structures such as vehicles and bridges, have low connection reliability, especially under alternating load and impact conditions. Looseness is easy to occur, the maintenance cycle is short, and the maintenance cost is high in the later period, which cannot meet the requirements of railway freight.
screw is a tool that uses the physical and mathematical principles of the circular rotation and friction of an object to fasten the mechanism of the object step by step. When using screws to fasten objects and parts, it is often necessary to use screws with churchill citychurchill cityspring washers and flat washers to lock and fix the relative position, so as to improve the stability of the fastening connection and make the screws less prone to loosening. However, in the prior art, the method of manually inserting the churchill citychurchill cityspring washer and the flat washer in sequence is generally used, which not only increases the workload of the staff, but also makes the installation efficiency relatively low. On the other hand, the traditional screw with a gasket only has the function of fixing, Without the function of sealing, it cannot be applied to special equipment such as oil tanks and airtight cabins. Therefore, it is necessary to design a screw that can reduce the workload and have its own sealing structure.
Materials and main equipment: 1.1 Bolts, nuts and washers shall be accompanied by quality certificates and shall comply with design requirements and national standards. 1.2 The high-strength bolts should be stored in categories according to their specifications, and should be protected from rain and moisture. Do not use if the bolts and nuts are not matched and the threads are damaged. If the bolts, nuts and washers are corroded, the tightening axial force should be sampled and used only after meeting the requirements. Bolts, etc. shall not be contaminated by soil or oil, and shall be kept clean and dry. It must be used in the same batch according to the batch number, and must not be mixed or mixed. 1.3 Main tools: electric torque wrench and controller, manual torque wrench, manual wrench, wire brush, tool bag, etc. 2 Operating conditions: 2.1 Friction surface treatment: The friction surface is treated by sandblasting, grinding wheel grinding and other methods, and the friction coefficient should meet the design requirements (a requirement is that the Q235 steel is above 0.45, and the 16 manganese steel is above 0.55). The friction surface wood is allowed to have residual iron oxide scale. The treated friction surface can generate red rust surface and then install the bolts (generally stored in the open air for about 10d). The sandblasted friction surface can be installed without rusting. When grinding with a grinding wheel, the grinding range is not less than 4 times the diameter of the bolt, the grinding direction is perpendicular to the direction of force, and the friction surface after grinding should be free of obvious unevenness. The friction surface should be prevented from being polluted by oil or paint. If polluted, it should be cleaned thoroughly. 2.2 Check the hole size of the bolt hole, the burrs on the edge of the hole must be removed. 2.3 The bolts, nuts and washers of the same batch number and specification should be packaged for use. 2.4 Electric wrenches and manual wrenches should be calibrated.
Ordinary churchill cityT-bolts, the bolt head is rectangular, the screw part and the bolt head are T-shaped, and the width of the head is smaller than the width of the opening part of the T-slot, so that the head of the T-bolt can extend from the length of the T-slot. Insert the T-slot into the T-slot at any position in the direction. When the workpiece needs to be fixed, turn the T-bolt 90 degrees so that the length of the head is perpendicular to the T-slot, hook the inside of the opening of the T-slot, and screw it by tightening The nut on the T-bolt threaded rod holds the workpiece in place. The T-bolt of this structure can easily connect the bolt and the base piece quickly, and is widely used, but there are also some shortcomings, due to the contact area between the head of the T-bolt and the inner side of the opening of the T-slot. If it is too small, the frictional resistance is correspondingly small. On the one hand, the bolts are easy to follow the rotation during the process of tightening the nut. Unreliable.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: square hole bridge rack bolts, churchill cityGB867 rivets, national standard metric screws, 6063 aluminum alloy screws and other products, we can provide you with suitable fasteners for you solution.