Wire drawing process
Pulling force is applied to the metal rod to pass through the die hole to obtain products with the same size and shape of the die hole. The plastic processing method standard drawing wire or wire drawing.
1. The main points of drawing round copper wire
1 When changing the appearance of the mold and changing the specifications, the wire diameter should be measured carefully and the surface quality of the wire should be observed
2 The coiled wire should be arranged neatly and evenly tensioned, and whether the gear opening is appropriate
3 The grease content of the lubricating fluid should meet the specified requirements
4 The processing requirements for the middle broken end of the copper wire in the coil, and the welding can be required to be flat
5 The amount of reel for each reel, the distance between the sides of the reel should be in accordance with the requirements
6Check the wire diameter frequently and change the mold immediately
Two, the main points of drawing round aluminum wire
1 No moisture is allowed on the surface of the aluminum rod
2 The drawn aluminum wire must have a special aluminum wire die
3The lubricant for drawing aluminum wire is special
4 There should be no oil stains on the surface of the aluminum wire
5 The drawing wire matching mold should be connected to the matching mold process card
Three, the type of drawing die:
Tungsten mold Polycrystalline mold Diamond mold
Fourth, the principle and method of wire drawing
1. Using the least number of stretching passes, each stretching takes full advantage of the plasticity of the metal
2. Reach the minimum number of wire breaks and increase the stretching coefficient
3. Obtain the exact required size and complete the plastic deformation of the metal
4. Obtain the required mechanical and electrical properties
Five, stretching equipment
Mainly divided into sliding wire drawing machine or non-sliding wire drawing machine
The development trend of wire drawing machines is high speed, high efficiency, continuity and multi-head.
Continuity refers to the realization of continuous production through processes such as wire drawing, annealing, tinning and extrusion: enameling. Multi-heading refers to multiple incoming wires, followed by twisting.
Six, wire annealing
During the stretching process of the metal material, the material is deformed. The essence is that the metallographic structure of the metal becomes tight, which causes work hardening, which is not conducive to further processing. The resistance also changes. The metal material needs to be heated at a certain temperature to make the metal The metallographic structure rearranges at a certain temperature and becomes recrystallized.
Now commonly used are continuous annealing and electric furnace annealing.
Continuous annealing should pay attention to: 1 wire tension is appropriate 2 wire contact wheel allows up and down jitter 3 annealing voltage and current should be constant.