What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The traditional fixture shown in Figure 2 is composed of a hardened support cylinder and a hardened shear bar, and has a simple structure. The cylindrical pin is loaded into the hardened support cylinder, and the shear test is completed by applying an axial load to the hardened shear bar. Since the standard stipulates that the gap between the loading part and the supporting part does not exceed 0.15mm, in order to ensure the matching of the gap during the shear test of the cylindrical pin, the diameter of the cylindrical pin on the cylinder is generally equal to the theoretical cylindrical pin. In practical application, the cylindrical pin is irregular in size after heat treatment. To realize the shear test, the cylindrical pin must be inserted into the hole with the help of external force, which is difficult to install and clamp and takes a long time. If the double-sided shearing is performed, that is If the cylindrical pins need to be installed on both sides, the time is doubled, and the notch of the cylindrical pins cannot be guaranteed to face upwards.
A nut provided by Yueluo. The nut is in the shape of a sleeve and has a threaded section inside. An annular groove is set on the inner wall of one end of the threaded section. The notch of the groove points to the hole core. The hole diameter at the groove notch at the front end is larger than the nominal size of the thread segment or the hole diameter at the groove notch at the rear end in the screwing direction is smaller than the nominal size of the thread segment.
Blind rivets are a type of rivets for single-sided riveting, but they must be riveted with a special tool - a rivet gun (manual, electric, pneumatic). This type of rivet is especially suitable for riveting occasions where it is inconvenient to use ordinary rivets (which must be riveted from both sides), so it is widely used in construction, automobiles, ships, aircraft, machinery, electrical appliances, furniture and other products. Among them, the open type oblate head blind rivets are the most widely used, the countersunk head blind rivets are suitable for riveting occasions that require smooth performance, and the closed blind rivets are suitable for riveting occasions that require higher load and certain sealing performance.
The defect of the existing press-fit solution is: when the retaining ring is placed in the chamfering section or the guide section of the shaft head, the retaining ring cannot be accurately fixed, and the retaining ring is easy to tilt or fall, especially when the shaft head is located inside the bearing chamber depression, The inclination of the retaining ring will make it difficult to press the retaining ring, affect the production efficiency, and even cause the product to be scrapped.
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