What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
As a commonly used data communication device, connectors are widely used in computers and TVs. Because common connectors such as D-SUB and DVI are composed of a male seat and a female seat, the iron shell of the male seat and the female seat is The corresponding position is provided with holes, the holes of the male seat are connected with rivets, and the holes of the female seat are correspondingly provided with screws for fixing. After the male seat and the female seat are connected, tighten the screws so that the male seat and the female seat are tightly connected together. When assembling on a computer or a TV, the rivet has a fixed assembly direction, and the fixation of the rivet direction is very important for assembly. However, there is no anti-rotation device on the iron shell hole connected with the rivet on the existing connector, and the rivet cannot be positioned during the assembly process, and it is easy to rotate and dislocate. production efficiency.
The positioning pin is a pin designed to accurately position the two adjacent parts of the mold in a mold composed of two or more parts. It can be seen that the positioning pin plays a positioning role, and the mold must be accurately synchronized when it is closed. product, and the positioning pin can make the upper and lower molds play a role in accurate positioning. In the mold design and manufacture of Yueluo, the positioning pin is one of the most common parts. Since it is only used for positioning between parts, few people will pay too much attention to it. In the cold stamping process of Yueluo, the dimensional accuracy of the blanking parts depends on the size of the working part of the punch and the concave die, and the dimensional difference between them constitutes the blanking die gap. Gap is an important process parameter for die design, and its size has a great influence on the quality of the section of the blanking part, the blanking force, and the life of the die. If the gap is too large, punching burrs will appear in punching; if the gap is too small, secondary cracks will occur in the section and extrusion burrs will appear, which will make the quality of the section after punching unsatisfactory, and a reasonable gap will not only help the punching section. The improvement of quality also contributes to the improvement of the lifespan of the 5-pack.
Standards are norms, and each country and sector has its own standards. GB—Chinese National Standard (National Standard) ANSI—American National Standard (American Standard) DIN—German National Standard (German Standard) ASME—American Society of Mechanical Engineers Standard JIS—Japanese National Standard (Japanese Standard) BSW—British National Standard GB—National Standard The standard is one of the many standards in my country, and there are also industry standards, professional standards and department standards. National standards are divided into: GB (mandatory standards) and GB/T (recommended standards) and GBn (national internal standards) and so on. We usually see GB30, GB5783, etc. are mandatory standards. In addition to some basic dimensions such as head-to-side, head thickness, etc., the above standards are mainly different in the threaded part. The threads of GB, DIN, JIS, etc. are all in MM (millimeters), which are collectively referred to as metric threads. Another thread like ANSI, ASME, etc. is called American standard thread in inches. In addition to metric threads and American threads, there is also a BSW-imperial standard, whose threads are also in inches, commonly known as Wyeth threads. In the usual domestic sales business, the most common standards we encounter are GB (National Standard) and DIN (German Standard). In terms of production products, the following standards are mainly encountered: GB30; GB5783; GB5782; GB52; GB6170; GB818; GB819; GB845; GB846; GB70; DIN912; DIN933; DIN931 and so on. GB30 (old national standard) has been replaced by GB5783 (new national standard) in the standard book. GB52 (old national standard) has been replaced by GB6170 (new national standard) in the standard book.
Shaft retaining ring (hereinafter referred to as retaining ring) is a very common part and is widely used in shaft parts. The existing solution for pressing the retaining ring is: place the retaining ring sleeve in the chamfering section or the guiding section of the shaft head, and then use an indenter whose inner hole diameter is larger than the diameter of the shaft head to press the retaining ring into the groove, and then press the retaining ring into the groove through the shaft head. The retaining ring is combined with the slot to prevent the indenter from continuing to move downward.
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