What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Most electrical appliance manufacturers only require the size and riveting gap to be tested for riveted contact components. There is no clear requirement for riveting strength. Only a few manufacturers perform torsion testing on riveting strength. The torque detection method is as follows: use a saw blade to open a one-shaped groove on the rivet head of the riveted contact element, and then insert a torque wrench into the one-shaped open groove to rotate, and measure the torque value. Because most of the electrical contacts are made of copper-silver alloy, the strength is low, and it is easy to slip during the test, and when a saw blade is used to open the one-shaped groove, the width and depth cannot be accurately positioned, so the measured value fluctuates greatly. , has always been an unsolvable technical problem in the industry.
hand screw is a screw with a plastic head, and the user fixes the hand screw by turning the plastic head by hand. At present, a hand screw is disclosed in the market publication number CN202203253U, which includes a plastic head and a screw rod, the plastic head and the screw rod are connected together, and the height of the plastic head is higher than that of an ordinary screw, and the height is 12 cm. The screw of the hand screw is fixed in the plastic head by glue. After a period of use, the aging of the glue leads to the loosening of the screw and the plastic head. When the plastic head is stressed, the screw rod comes out of the plastic head, which affects the normal use of the hand screw.
The inner tooth elastic washer and the outer tooth elastic washer have many sharp elastic warping teeth on the circumference, which are pressed against the supporting surface and can prevent the loosening of the fastener. The inner tooth elastic washer is used under the screw head with smaller head size; the outer tooth elastic washer is mostly used under the bolt head and the nut. The elastic washer with teeth is smaller than the ordinary spring washer, and the fastener is evenly stressed and reliable to prevent loosening, but it is not suitable for frequent disassembly. Wave spring washer GB: GB/T 7246-1987 Wave washer is divided into WG type, WL type, WN type WG type wave washer WG type wave washer is an open elastic washer, which can usually be installed in a small space, such as giving The bearing is prestressed to reduce the noise of the bearing operation and improve the running accuracy and stability of the bearing. In addition, there are a large number of applied materials in electronic appliances, such as carbon steel, stainless steel, copper alloy and so on. WL-type wave washer WL-type wave washer is a lap-type elastic washer, which can usually be installed in a small space, such as prestressing the bearing, reducing the noise of the bearing operation, and improving the running accuracy and stability of the bearing. There are also a large number of applications in electronic appliances. Materials are carbon steel, stainless steel, copper alloy, etc. WN type wave washer WN type wave washer is a multi-layer wave crest overlapping elastic washer. Compared with the WL type, this series is composed of multi-layer materials, so the K value curve under the same compression stroke is flatter than that of the WL type, which is suitable for elastic force. Larger, and the elastic release of the entire working stroke is required to be more uniform. The materials used are carbon steel, stainless steel, copper alloy, etc. Disc spring washer Disc spring washer, also known as Belleville spring washer, was invented by the French Belleville. DIN6796 Disc Spring Washers (HDS Series) are lock washers designed for bolted and screwed connections. It is designed and manufactured according to DIN 6796 for the connection of medium or high strength bolts and screws. High bearing loads and elastic recovery make the HDS series very effective, and the bolt tension can withstand slack due to: wear of consumables, creep, relaxation, thermal expansion, contraction, or compression of seals. The HDS series increases the elasticity of the screw several times. It can effectively replace the ordinary spring washer, but it is not suitable for the combination of lock washer and flat washer. 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.
The use of stainless steel screw lines: The hardness of stainless steel screw lines causes them to have different uses. Generally, they are used as small screws in life, but also as car screws and compression screws. They are widely used in normal life. Types of stainless steel screw lines: In appearance, screw lines are generally divided into fog surface spring lines and bright surface screw lines. The hardness of matte surface screw lines is higher than that of bright surface screw lines. For products with low appearance requirements and relatively high elasticity requirements. Paper, oxalic acid, fertilizer and other production equipment; photography, food industry, facilities in coastal areas, ropes, CD rods, bolts, nuts.
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