What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Installation method broadcast 1. One-time burying method: When pouring concrete, bury the anchor bolts. When the high tower is controlled by overturning, the anchor bolt should be buried once. 2. Reserved hole method: The equipment is in place, the holes are cleaned, the anchor bolts are placed in the holes, the equipment is positioned and aligned, and then poured with non-shrinkage fine stone concrete that is one level higher than the original foundation, and compacted and compacted. . The distance from the center of the anchor bolt once buried to the edge of the foundation should not be less than 2d (d is the diameter of the anchor bolt), and should not be less than 15mm (d≤20, it should not be less than 10mm), not less than half the width of the anchor plate Add 50mm, when the above requirements cannot be met, appropriate measures should be taken to strengthen it. The diameter of the anchor bolts used for the structure should not be less than 20mm. When subjected to earthquake action, double nuts should be used for fixing, or other measures to effectively prevent loosening should be adopted, but the anchorage length of anchor bolts should be increased by 5d compared with the anchorage length of non-seismic action. Installation planning of anchor bolts Treatment of anchor bolts loose in the foundation When the anchor bolts are tightened, the bolts may be pulled out. At this time, the bolts should be adjusted to their original positions, and the foundation around the bolts should be shoveled out enough. , and then weld two U-shaped steel bars vertically and horizontally on the bolts, and finally clean the pit with water and grouting, and then tighten the live anchor bolts after the concrete has solidified to the design strength. The treatment method of the live anchor bolt deviation is roughly the same as the dead ground. The method for the anchor bolts is the same, except that the anchor bolts can be pulled out for processing. If the bolt is too long, a section of the thread can be cut off on the machine tool; if the bolt is too short, it can be extended by hot forging; if the position is inconsistent, it can be corrected by bending. Application industry: suitable for various equipment fixing, steel structure foundation embedded parts, street lights, traffic signs, pump, boiler installation, heavy equipment embedded fixing, etc.
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 the design of modern aviation and aerospace vehicles, in order to reduce weight and save space, the space of the fastening installation system is getting narrower and narrower, and blind hole installation is often required. In this case, single-sided riveting installation is usually used for fastening connection. At present, this kind of fastening connection products are mainly blind rivets. The riveting installation principle of blind rivets is to use the method of pulling, pulling the mandrel, and extruding the nail sleeve to deform it at the blind end to achieve the function of fastened connection. This kind of fastening connection method requires special riveting, generally imported riveting, the replacement of internal parts is expensive, the installation process is complicated, and the installation cost is high.
The commonly used tools for fixing screws on the surface of the workpiece are electric screwdrivers and manual screwdrivers. Both of these screwdrivers manually attach the screws to the bits of the electric screwdriver or manual screwdriver, and then fix the screws on the surface of the workpiece. The screwdriver is inefficient in fixing the screw, and cannot accurately locate the screw fixing point.
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