What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The retaining ring is a ring-shaped body with an opening, and the traditional processing method is stamping. That is, a plate-shaped material is selected and punched out on the plate-shaped material (a circular body, and then the middle of the circular body is punched to form a ring-shaped ring body.) The punched material in the middle cannot be used again. This results in a waste of material.
Some electronic products need to install some plastic parts or protective sleeves for components on the PCB, which need to be fixed by screws. The function of the fixture is to locate the PCB and the required installation parts, and increase the work efficiency. The existing screw fixture is inconvenient According to the needs of the site, the positioning station of the screw can be changed, the accurate positioning of the screw is difficult and the clamping effect of the workpiece is poor. A screw jig is proposed.
Stamping die is a special process equipment for processing materials into parts in cold stamping processing, called cold stamping die. Stamping is to use the die installed on the press to apply pressure to the material at room temperature to make it produce Separation or plastic deformation to obtain the required parts of a pressure processing method, the technology generally used is to make corresponding holes and punches on the template, this method cannot meet the requirements for small batches and short delivery time products , the relative cost is relatively high, so a rivet die structure is required to improve the above problems.
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 13 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
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