Service HotlineThe existing screw generally includes a round table-shaped nail body with one large end and one small end, a threaded section is provided on the radial circumference of the nail body, a small end of the nail body is provided with an inclined tip, and the large end of the nail body is provided with a nail cover. , generally used on materials that are softer than the screw, and drill into the object to be nailed through its own rotation. When drilling, the thread plays the role of rotary cutting, so that the screw is drilled forward, but when the thread cuts the object to be nailed When it is shaken for a long time, the tightening force of the screw in the axial direction is not enough, it is easy to loosen, and there is a potential safety hazard.
The difference between high-strength bolt friction type and pressure-bearing type connection: High-strength bolt high-strength bolt connection is to clamp the plate of the connecting plate through a large tightening pre-pressure in the bolt rod, which is enough to generate a large friction force, thereby improving the connection. The integrity and stiffness of the bolt can be divided into two types: high-strength bolt friction type connection and high-strength bolt pressure type connection according to different design and force requirements when subjected to shear force. The essential difference between the two is that the limit state is different, although It is the same kind of bolt, but it is very different in terms of calculation method, requirements, and scope of application. In the shear design, the friction type connection of high-strength bolts is the limit state when the external shear force reaches the possible maximum friction force provided by the bolt tightening force between the contact surfaces of the plates, that is, the internal and external shear force of the connection is guaranteed not to exceed maximum friction. The plate will not undergo relative slip deformation (the original gap between the screw and the hole wall is always maintained), and the connected plate will be elastically stressed as a whole. In the design of shear resistance, the external shear force is allowed to exceed the maximum friction force in the high-strength bolt-bearing connection. At this time, relative slip deformation occurs between the connected plates until the bolt rod contacts the hole wall, and then the connection depends on the bolt rod. The shearing of the body and the bearing of the hole wall and the friction between the contact surfaces of the plates jointly transmit the force, and finally the shearing of the shaft or the bearing of the hole wall is regarded as the limit state of the connection shearing. In a word, friction type high-strength bolts and pressure-bearing high-strength bolts are actually the same type of bolts, but whether the design considers slippage. Friction type high-strength bolts can never slide, and the bolts do not bear shear force. Once slipped, the design is considered to reach a state of failure, which is technically mature; pressure-bearing high-strength bolts can slide, and the bolts also bear shear force, and the final damage is equivalent to ordinary Bolt failure (bolt shearing or steel plate crushing).
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.
However, Yueluo still feels that there should be room for improvement for the screw improvement and screw that integrates stability, labor, fast and multi-function in the above two cases; for example, No. 556784 screw improvement Although the rod has the function of cutting and collecting chips, when the screw starts to screw into the object such as wood, it is hindered by the hardness of the object's tissue, so the staff still needs to exert considerable force, resulting in the lock. In the solid operation, there is still a lack of difficulty in screwing in operation; another example, new cases such as No. 289408 screw that integrates locking, stability, labor, fast and multi-function, although the rod has the structural function of cutting and chip removal, it is The rod part is screwed into the middle section to the rear section of the object. Since the debris cannot be discharged, the rod part pushes the outer part of the object to the surrounding tissue of the object, so that the object expands outwards and even seriously damages the appearance of the object.
The assembly of hollow rivets and flat head screws riveted on the cover plate is assembled in the product. Compared with the method of connecting with bolts, the loading and unloading speed can improve the efficiency by about 80% to 90%, and is widely used. The assembly needs to riveted hollow rivets and flat head screws on the cover plate, and ensure that the riveted flat head screws can rotate flexibly. When riveting, it is necessary to use special tools to riveted the hollow rivets, flat head screws and cover plates together for riveting. In the existing riveting process, the oval head screw is often damaged due to the action of external force. The positioning process is cumbersome and the work efficiency is low.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: DIN582 lifting bolts, driving bolts, aluminum welding screws, welding square nuts and other products, we can provide you with suitable fasteners for you solution.
