What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
concealed screw fastener includes a washer, a screw and a shield, one end of the screw is provided with an end cap, the screw penetrates the washer and the end cap is supported on the washer, and the shield covers the end of the screw The cap is peripheral and connected to the gasket. When in use, firstly pass the screw through the washer and then drive it into the screw hole of the connected piece, and then cover the shield on the outer circumference of the end cap of the screw and connect it with the washer.
In the riveting connection of various structural parts, waterproof lantern rivets have been widely used in riveting environments that require waterproofing. After the riveting parts are riveted, the waterproof structure area of the mandrel and the waterproof structure of the rivet body There is no complete close fit between the areas. In some riveting ranges, the waterproof performance of the rivet is affected. The main reason is that the traditional processing technology of the mandrel and the materials used bring many troubles to the riveting process. is a problem to be solved at present.
As my digital TV technology becomes more and more mature, more and more people with digital-to-analog signal conversion function enter people's lives. Therefore, the number of production and processing is also increasing day by day. There are many requirements for the form, reliability and cost of PCB fixing screws in production. One of the existing fixing methods is to fix by means of bolts and nuts. The operation steps are to place the PCB board on the inner threaded copper column connected to the casing, and pass through the bolts with fine teeth. Screw holes on the PCB board, and then fix them on the copper posts with nuts. The connection method of this solution is reliable, but its manufacturing cost is high, and the copper column and the metal shell need to be screwed together, resulting in low production efficiency and high cost. In addition, there is also a common way that the PCB is supported by a plastic column, and the self-tapping screw is passed through the screw hole on the PCB board, and the PCB board and the metal bottom shell are connected by the self-tapping thread on the screw. The main disadvantage of this solution is that after the screw is fixed on the metal shell, the screw head is exposed at the bottom of the machine. If the user is not careful during use, the hand scratching phenomenon will occur, which will bring changes and harm to the user's use. . And when the machine slides on the desktop, if the screw head is too exposed, it will scratch the desktop. Therefore, how to provide a PCB fixing method with convenient operation, reliable connection and low production cost is a technical problem to be solved urgently in the industry.
In order to meet the needs of different assembled installation components, there are also hand-tightening methods for tightening the screws, but in actual use, ordinary manual screws can easily cause hand pain to the user, and the operation is extremely inconvenient; at the same time, due to tightening The contact area between the screw and the installation component is too small. If the user exerts too much force, the uneven force per unit area of the installation component will cause deformation and depression, which will affect the use. Therefore, a manual screw is proposed to solve the above problems.
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