What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
With the rapid development of electronic technology, the integration of circuit boards is getting higher and higher, and the number of layers of circuit boards is increasing. Press-fit and fix to ensure accurate alignment during riveting and pressing. The rivets used on PCB boards are basically brass rivets. When riveting and pressing multi-layer PCB boards, metal chips are prone to appear, inner layer short circuits or foreign objects between layers, and because of the brass rivets With higher hardness and larger wall thickness, the riveted area of the PCB is thicker than the non-riveted area, which is easy to cause damage to the middle steel plate of the auxiliary tool. At the same time, the protruding rivets hinder the free expansion of the copper foil, which is easy to produce copper foil. wrinkling phenomenon. Now there are improved plastic rivets used to manufacture multi-layer PCB boards. The advantage is that no metal debris is generated, and at the same time, the tool steel plate is not damaged to the greatest extent. However, the existing plastic rivets are insufficient due to the inherent strength of plastics. When the PCB board is riveted and pressed, it is easy to deform, and the positioning is inaccurate, resulting in dislocation between layers, resulting in poor improvement of the product defect rate.
The general nut will loosen itself due to vibration and other reasons during use. In order to prevent this phenomenon, the self-locking nut was invented. The main functions of self-locking nuts are anti-loose and anti-vibration. For special occasions. Its working principle is generally self-locking by friction. The types of self-locking nuts classified by function include those with nylon rings, those with neck closures, and those with metal anti-loosening devices. They are all effective torque type lock nuts (refer to GB/T3098.9-2002 national standard)
Compared with the prior art, the technical effect of Yueluo Company is: during the screwing process of the nut, the tube wall of the nut is elastically deformed so that the convex ring on the screw is matched with the groove on the nut, and the slope of the convex ring matches the groove. The groove wall is abutted against to limit the relative position of the nut tube and the screw shaft in the axial direction, which not only ensures the reliability of the threaded connection, but also achieves a significant anti-loosening and anti-falling effect. After the threaded connection, excessive force is applied to remove the nut and screw, so that it can be reused to save costs.
1. When the main body is large equipment, accessories need to be installed, such as sight glass, mechanical seal seat, deceleration frame, etc. At this time, a stud bolt is used, one end is screwed into the main body, and the other end is equipped with a nut after the accessory is installed. Since the accessory is often disassembled, the thread will be worn or damaged, and it is very convenient to use the stud bolt to replace. 2. When the thickness of the connecting body is very large and the bolt length is very long, stud bolts will be used. 3. It is used to connect thick plates and places where it is inconvenient to use hexagonal bolts, such as concrete roof trusses, roof beam suspension monorail beam suspension parts, etc.
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