1 Introduction
The production process of rod breakdown machine includes three processes: drawing, annealing and coiling. Wire breakage is a big problem during the drawing process, which generate a large amount of waste wire, increase working hours, and reduce production efficiency. Therefore, studying and analyzing the reasons for wire breakage and adopting corresponding effective measures to reduce the wire breakage rate is of extremely important significance to the stable operation of the copper rod breakdown machine.
2 Analysis of causes of wire breakage
The main reasons for wire breakage during the drawing process of copper rod breakdown machine include raw materials, drawing dies, drawing capstans, drawing emulsions, copper rod welding, etc. The performance of wire breakage caused by different reasons is different. Through in-depth exploration and analysis, the main reasons as follows.
2.1 Raw materials
Most of the raw materials used by the copper rod breakdown machine are φ8mm copper rods produced by CCR line. The quality of the copper rods directly affects the production of the copper rod breakdown machine.Common causes of wire breakage in raw materials include hollows and inclusions. Because pores are generated during the casting process of the CCR line, and the pores cannot be completely eliminated in the subsequent rolling process, hollows are generated and lead to wire breakage. During the casting process of the copper rod, impurities such as refractory materials and cold copper particles are brought in, which causes the copper rod to break during the subsequent drawing process.
2.2 Drawing die
The copper rod breakdown machine achieves drawing by plastic deformation of the drawing die. The selection and quality of the die play a very important role in the production flow and product quality of the copper rod breakdown machine. The main reasons for die affect wire breakage are the following three aspects.
Die structure: For different copper wires, the optimal die angle is also different. The specifications of the die must meet the process requirements. For example, if the die angle is too large, the lubrication distance is too short, and the lubrication is insufficient, it will cause wire breakage.
Die matching: At present, most copper rod breakdown machine adopt multi-die continuous drawing production technology. The die ratio of each pass in the entire production process is comprehensively set based on the production process, transmission, etc. When the die size changes, This leads to changes in the pass processing rate and can easily cause wire breakage.
Copper powder: During the drawing process of the copper wire, some copper powder is produced due to the base material itself and the friction between the base material and the die. As the drawing progresses, some of the copper powder will follow the copper wire. Through the die hole, it is brought into the finished die cavity. As time goes by, the copper powder accumulates more and more, forming hard lumps, resulting in wire breakage.
2.3 Drawing capstan
During the copper drawing process, most of the copper wires are driven through the drawing capstan. If the surface of the drawing capstan is grooved, or the angle of the drawing capstan is too large or too small, this will cause the copper wire to be unable to form on the drawing capstan. The copper wires are arranged in sequence on the surface of the tensile capstan, causing the copper wires to squeeze each other and fold with each other to produce wire pinches, resulting in wire breakage.
2.4 Drawing emulsions
In the copper wire drawing process, drawing emulsion is a very important auxiliary material. The correct use and management of drawing emulsion play an extremely important role in further improving the quality of copper wire and reducing the wire breakage rate. The main functions of the drawing emulsion are lubrication, antioxidant, cooling, cleaning, etc. All functions should meet the requirements of the copper rod drawing production process. The emulsion forms a lubricating film between the copper rod blank and the die hole to reduce friction. At the same time, the copper mud on the drawing ring and die can be cleaned. If the lubrication and cleaning effects are not good, wire breakage will occur.
2.5 Welding
In order to ensure the continuous and stable production of copper rod breakdown machine, welding technology must be used to connect the copper rod blanks end to end. At present, there are two types of copper rod welding: hot melt welding and cold pressure welding. The welding quality directly affects the stable production of copper rod breakdown machine. Reasons such as uneven and skewed welding joints, oil stains and other impurities on the surface of the welding end, failure of the welding temperature to meet process requirements, and weak clamping of the welding fixture will affect the welding quality and cause wire breakage in subsequent production.
3 Solutions for wire breakage
Through long-term production practice exploration and analysis of the causes of the above surface defects, further optimization of the process, and continuous improvement of equipment, the wire breakage rate of copper rod breakdown machine can be greatly reduced. The main measures include the following aspect.
3.1 Quality assurance
Choosing high-quality copper rods is a prerequisite for ensuring the smooth production of copper rod breakdown machine. To ensure the quality, the quality of the copper rod blanks is judged according to the production process of the previous process (continuous casting and rolling copper rod production line), , choose the appropriate production.
3.2 Drawing die
Die is one of the important components in the production of copper rod wire drawing machine. Its selection is directly related to the quality of the product and the smoothness of production. Therefore, reasonable dies and processes should be selected. Every time a new die or a reworked die is used, the dimensions must be measured online to confirm whether the dimensions meet the process requirements, the maintenance and upkeep of the drawing die must be done, the die use and maintenance regulations must be formulated, and the die must be removed from the machine for maintenance on a regular basis during the production process. The copper mud in the finished die cavity must be cleaned regularly.
3.3 Drawing capstan
During the use of the drawing capstan, the process requirements must be met, and the size must be controlled within the tolerance range. As production proceeds, grooves will appear on the surface of the drawing capstan to varying degrees. When the grooves are deep and affect the production of large copper drawings, The side must be changed or a new drawing capstan must be replaced.
3.4 Drawing emulsions
Most of the drawing systems use immersion lubrication. The concentration, pH, temperature and bacterial content of the drawing emulsion must be ensured. Various indicators of the emulsion must be regularly tested. During the production process, if the indicators of the emulsion do not meet the standards, they must be adjusted in place before starting the machine.
4 Summary
(1)There are many factors that affect the wire breakage in the production process of copper rod breakdown machine. The main reasons are: raw materials, dies, drawing capstans, emulsions, etc. Therefore, analyzing and determining the cause based on the specific circumstances of the breakage and taking effective targeted measures are crucial to improving product quality and ensuring stable production operation.
(2) Through measures such as raw material selection, die optimization, equipment optimization and reasonable control of production processes, the occurrence of wire breakages in the production process of copper rod breakdown machine can be greatly reduced and the normal production of copper rod breakdown machine can be ensured.