What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
screw is a common threaded connection part, which is mainly used to fix a part on the connection body. When it is necessary to connect, use the screw to pass through the hole on the connected parts, and screw the external thread on the screw into the connecting body to tighten it; The coupling part is separated from the coupling body. Existing common tools for screw disassembly and assembly are generally adjustable wrenches, open-end wrenches, Torx wrenches, socket wrenches, Allen wrenches, flat-blade screwdrivers, cross-shaped screwdrivers, etc., and a screw can only be disassembled with one or one type of tool. Assembly work; when the types of tools are not complete, the screw disassembly and assembly work is difficult to complete, and the screw disassembly and assembly work is greatly limited by the tools.
In the riveting operation, the rivet used is composed of a mandrel and a deformed collar. When in use, a through hole is drilled on the two components to be connected, and then the head of the rivet is passed through the through hole and clamped by a rivet. The tail of the rivet will break the rivet, the head of the rivet and the deformed collar remain in the through hole, and the whole riveting process is completed. The existing pull rivets have the following shortcomings: first, the parts where the pull rivet and the two components are connected cannot be completely and tightly fitted, which meets the requirements of non-sealing for parts that have waterproof and leak-proof requirements; second, the existing pull rivets The separation groove of the rivet mandrel is close to its head. When the mandrel is broken by the rivet during the riveting process, basically only the head of the mandrel remains in the deformation collar, and the connection of the two components depends on the deformation of the collar. Under the action of compressive stress, the inside of the deformed collar becomes hollow due to the breaking of the mandrel, and cannot bear large shear stress.
In the past production, gaskets were generally obtained from two channels: first, standard gaskets were mostly purchased from the market, and the cost was high; non-standard gaskets, due to the small demand, required separate tooling and molds, which were expensive and long production cycle. It is difficult to purchase; Second, the plate is purchased by the enterprise, and then the washer is formed by the automatic cutting machine. Because the cut nodules and cut marks produced by flame cutting do not meet the requirements for use, the inner and outer diameters need to be reserved 2 ～3mm machining allowance, and then finish the outer diameter and inner diameter by lathe.
On the surface of the mounting hole on the connector, a 90-degree conical socket is machined, and the head of the flat machine screw is in the socket and is flush with the surface of the connector. Flat machine screws are also used in some occasions with semi-circle head flat machine screws, which are more beautiful and are used for places where a little protrusion is allowed on the surface. Screws play the role of connecting two or more objects and are an indispensable necessity in daily life or industrial manufacturing. There are countersunk head bolts (with grooves) and countersunk head bolts (with tenon).
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
