What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Stud bolts generally need to be surface treated. There are many types of bolt surface treatments. Generally, electroplating, blackening, oxidation, phosphating, and electroless zinc flake coating are commonly used. However, electroplated fasteners account for a large proportion of the actual use of fasteners. Especially in automobiles, tractors, home appliances, instrumentation, aerospace, communications and other industries and fields are more widely used. However, for threaded fasteners, not only a certain anti-corrosion capability is required in use, but also the interchangeability of threads must be ensured, which can also be called screwability here. In order to meet the dual-use performance of anti-corrosion and interchangeability required by threaded fasteners in use, it is very necessary to formulate special plating standards. [1] The GB/T5267.1-2002 [Threaded Fastener Electroplating Coating] standard is one of the national standards Fastener Surface Treatment series of standards, which include: GB/T5267.1-2002 [Fastener Electroplating Layer]; GB/T5267.2-2002 [Fastener electroless zinc flake coating] two standards. This standard is equivalent to the international standard ISO4042; 1999 [Threaded fastener electroplating layer]. This standard replaces the GB/T5267-1985 [Threaded Fastener Electroplating Coating] standard.
At present, the stopping method of the pin shaft stop pin of the general hydraulic excavator is mainly by using a long bolt to pass through the pin shaft stop sleeve pin hole and the pin shaft pin hole, and then use a double nut on the other end of the bolt to force it away from the pin shaft. The outer circle of the stop sleeve is about 2 3mm away to prevent the bolts and nuts from falling off. Due to the structure in which the double nuts are pressed against each other, the disassembly and assembly efficiency of this pin shaft stop method is not high, and two wrenches are required for each assembly and disassembly, which is extremely troublesome.
The flange nut and the general hexagon nut are basically the same in size and thread specification, but compared with the hexagon nut, the gasket and the nut are integrated, and there are anti-skid tooth patterns on the bottom, which increases the nut and the workpiece. Compared with the combination of ordinary nut and washer, it is stronger and has greater tensile force. In some equipment with large vibration amplitude, due to the action of huge vibration force, the flange nut is prone to loosening, which often occurs. If the flange nut falls off the equipment or even damages, the staff also needs to install the flange nut repeatedly, which increases the labor intensity and brings great inconvenience to the use. Now a split type tightening nut is proposed.
At present, in the power industry, for the fixing of terminals, most of the terminals are directly locked to the fixing screws using U-shaped clips. However, since the contact surface often cannot reach the level of flatness, it will cause difficulties in locking, and it will take a long time. Easy to loose and fall off. Although the use of spring clips is effective, due to the influence of its own width, the use of spring clips is not very extensive. Contents of the utility model The purpose of Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. is to provide an automatic locking screw for fixing the U-shaped clip. In order to achieve the above purpose, Yueluo adopts the following technical solutions: an automatic locking screw. From bottom to top, there are screw head, screw rod and nut with external thread. The screw rod is a hollow screw rod, and the hollow screw rod is on both sides. Long holes are respectively provided, the width of the long holes is smaller than the inner diameter of the hollow screw rod, a spring is arranged in the inner cavity of the hollow screw rod, the upper end of the spring is provided with a plug, and the two wings of the plug protrude out of the hollow screw rod through the long hole. The spring described by Yueluo is not less than the length of the hollow screw rod in the free extension state. The distance between the two wings of the plug described by Yueluo is greater than the diameter of the nut. Yueluo adopts Guangdong Yueluo Hardware Industry Co., Ltd., which can easily realize the automatic locking of the U-shaped clamp, and can be adjusted according to the thickness of the U-shaped clamp to ensure the close contact between the U-shaped clamp and the connecting screw.
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