What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The embedded nut is made of copper nuts made of various embossed wires (usually lead brass, such as H59, 3604, 3602). The embedded knurled copper nuts that we come into contact with on a daily basis are processed by precision automatic lathes. The reference standard for embedded knurled copper nuts comes from the national standard GB/T809. The main operation method of the anti-loose nut is to inject the embedded knurled copper nut. After heating, it is embedded into the plastic part or directly injected into the mold. If the mold is injection-molded, the melting point of PA/NYLOY/PET is above 200°C , After the embedded nut is hot melted into the plastic part, the temperature rises rapidly. After injection molding, the plastic body rapidly cools and crystallizes and becomes hard. If the embedded nut temperature is still at a high temperature, it may fall to the place where the copper nut contacts the plastic part. Start to loosen or crack. Therefore, copper nuts are used instead of carbon steel nuts in the injection molding of embedded nuts. There are two ways to form the external knurling of the embedded copper nut. One is to use copper raw material to draw the knurl and then to produce it on the upper equipment. Generally, the pattern of this method is straight, and the other is to use The round copper material is directly embossed while tapping during the production process. This processing method can produce some non-standard size knurled copper nuts. The embossed shape of the embedded copper nut can be selected by the user, such as mesh, Character embossing, herringbone embossing and other knurling patterns.
With the vigorous development of the construction market, fastener-type steel pipe scaffolding and formwork support have been widely used, and a large number of fasteners are used in the fastener-type steel pipe scaffolding and formwork support system. The commonly used fastener structure generally includes a fastener body 1, a blade 2, and a rivet 3 for connecting the fastener body and the blade. An arc-shaped cavity 4 for penetrating the steel pipe is provided between the fastener body and the blade. Figure 1 Right-angle fasteners shown. However, in the process of building construction, the blades of the fasteners have different degrees of cracks and fractures, which lead to the scrapping of the fasteners, or the fasteners are scrapped due to the poor anchoring of the rivets of the fasteners, resulting in a lot of waste, and the fasteners are damaged. There is a large safety construction hazard. However, repairing damaged fasteners entirely by hand has many disadvantages, such as technical difficulty, time-consuming and labor-intensive, and high operating costs. Therefore, researching and designing an auxiliary device for installing rivets in the process of repairing damaged fasteners to reduce labor intensity of workers, improve repair efficiency, and reduce operating costs is a technical problem to be solved urgently by those skilled in the art.
Yueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 4 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
pressure riveting nut pressure riveting tool Yueluo relates to a tool, specifically a pressure riveting nut pressure riveting tool. [Background Art] In order to quickly press riveting nuts, and to quickly switch press rivet nuts of different specifications and properties, and to ensure the press riveting strength between the press riveting nut and the piece during the press riveting process, a kind of Press riveting tooling. In order to overcome the deficiencies of the prior art, Yueluo provides a pressure riveting tool that can improve the strength of the pressure riveting and can switch the pressure riveting nut of different specifications and properties.
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