What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Pins are widely used. In the connection of the rotating mechanism of two moving components, such as the crank mechanism, the turning mechanism, the connection between the hydraulic cylinder and the moving parts, the pins are used. kind. In order to ensure the normal use of the running equipment and prevent the cylindrical pin from slipping out and falling off during use, some anti-falling methods are usually used at the head of the pin, such as 1. Drill holes and insert cotter pins to prevent the pins from slipping out; 2. The external thread is tightened with a nut to prevent the pin from slipping out; 3. The slot is clamped with a circlip to prevent it from slipping out, etc. These measures make the cylindrical pin very practical in the case of infrequent disassembly and assembly, but in the actual use of the field, in order to prevent the collision of some equipment during each troubleshooting or maintenance, the pin needs to be pulled out and turned up, etc. After the failure or maintenance is completed, put down and then insert the pin to restore, this process will bring trouble to the actual operator. For example, special tools must be brought with you every time you disassemble and assemble the pin, and the split pin or the circlip is easily damaged after repeated disassembly and assembly. , In order to save trouble, the operator sometimes uses iron wire to thread or fasten it instead, and even does not remove the pin for the sake of speed and convenience, which is easy to cause damage to the equipment when dealing with faults.
Since the HDS series is a disc spring that can be folded or overlapped. The combination of the butt joint can increase the deformation of the disc spring group, and the combination of the overlapping method can increase the spring force of the disc spring group. The ideal installation method is to flatten as much as possible. The closer it is to the flattened state, the faster the tension torque increases, and the proper bolt tension can be obtained without a torque wrench.
At present, with the development of the manufacturing industry, many parts with strange shapes are widely used in aviation, aerospace and other industrial fields, one of which is an L-shaped cylindrical pin. The upper end is provided with a 2.55×4.95 U-shaped boss. The parallelism error between the upper end face and the lower end face of the boss is required to be less than 0.01 mm. The L-shaped cylindrical pin requires high machining accuracy and is difficult to clamp on the machine tool. It is difficult to process. When the forming part is cut off, the cut surface, that is, the upper end surface of the boss, will leave a small column platform. When processing this end surface, in the prior art, a vise is generally used to process such an L-shaped cylindrical pin. Or copper sleeves are clamped, and then processed; however, due to the small size of the parts, the L-shaped cylindrical pin workpiece is difficult to clamp; due to the high precision required for each machined surface of the workpiece, when clamping with a vise , the clamping force of the vise is difficult to control, and it is easy to crush and scratch the surface of the workpiece; and when using a vise or a copper set clamp, only one workpiece can be clamped for each processing and production, and it is difficult to ensure the upper and lower planes of the parts after the clamping is completed. Parallelism machining error, resulting in low parts processing quality and low production efficiency.
In CN203807560, nails and bolts are used to connect the plates, but the heads of the nails and the bolts are enlarged ends that are wider than the rods, and the heads of the nails and the bolts cannot penetrate into the interior of the door body, so in terms of appearance, the more More nails and bolts will leave more spots on the surface of the door that are not suitable for the door itself. In the prior art, the treatment method for these spots is generally to paint with paint, which can only make the door panel consistent with the head of the nail and the bolt in color, but cannot change the shape of the head of the nail and the bolt, and the appearance is still good. Obvious spots were noticed, which made the door panels connected by nails and bolts to the panels, which could not be used as door panels for household doors.
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