How is a copper busbar manufactured?

I. Introduction to Copper Busbars and Pre-Processing Preparation

Copper busbars, also known as busbars, are long, rolled conductors made of copper (usually pure copper or brass). Their cross-sections are mostly rectangular, but can also be round or other irregular shapes. They are essential components in power transmission and distribution equipment (such as distribution cabinets, transformers, and switchgear), carrying and distributing high currents.

Before processing, two key preparations are required:

1. Drawings and Programming: Engineers use software such as CAD to create unfolded and bending diagrams of the copper busbars, noting all dimensions, hole diameters, bend positions, and angles. Dedicated CAM software then converts the drawings into G-code or a specific machining program that can be interpreted by CNC machines. This program contains instructions for all machining steps, such as where to cut, where to punch holes of what size, and the angle and direction of the bends.
2. Equipment and Material Preparation: Operators place raw copper busbar material, either in rolls or in cut-to-length quantities, onto the machine’s loading rack. On the CNC three-in-one machine, the corresponding dies (shearing blade, punching die, and bending die) are set up, and the pre-programmed program is input into the CNC system.

II. Core Processing and Manufacturing Process (with the CNC three-in-one machine as the core)

With everything in place, the journey to automated copper busbar processing officially begins.

Step 1: Loading and Positioning

The operator straightens the copper busbar roll or directly feeds a long, straight busbar onto the processing machine’s feed platform. The CNC system drives a servo motor, which grips the busbar via precision rollers and precisely moves it to the programmed initial processing position. The machine’s clamps securely hold the busbar in place to prevent it from moving during processing.

Step 2: Cutting

This is the first step in the process, aiming to cut the long copper busbar into the desired length as programmed.

· Process: According to the program instructions, the CNC system drives the feed mechanism to feed the busbar to the desired length. Then, a powerful hydraulic or servo-electric system drives the upper blade downward, working in conjunction with the lower blade to cut the busbar cleanly and efficiently, like a pair of scissors. Technical Key Points: CNC shearing ensures perpendicularity, flatness, and burr-free cuts, preventing issues such as increased contact resistance and heat generation caused by uneven contact surfaces during subsequent installation.

Step 3: Punching/Mesh Punching
This is the most common and most varied process, used to create mounting holes, connection holes, grounding holes, insulator slots, or heat dissipation mesh holes on copper busbars.

Process: A feed mechanism moves the sheared copper busbar (or directly onto a long piece of stock) to the punching station. The punching unit is typically a “cross slide” that moves along the X and Y axes, with a punch die mounted on top. The system, according to the program, precisely locates the first hole. The hydraulically driven punch instantly descends, engaging the lower die below, punching a round, square, irregularly shaped, or oblong hole in the copper busbar. Upon completion, the slide moves to the next coordinate and continues punching until all holes are processed. Technical Key Points:

Mold Library: Three-in-one machines are typically equipped with a multi-station mold library (such as a turret type) that can pre-install dozens of molds of varying sizes and shapes. These are automatically called up by the program during processing, eliminating the need for manual replacement and significantly improving efficiency.

High Precision: CNC positioning ensures precise hole placement, with hole pitch tolerances controlled to within ±0.1mm, ensuring perfect alignment of all connection points within the complete machine.

Step 4: Bending
This is a critical step in giving the copper busbar a three-dimensional shape, enabling it to circumvent obstacles, fit within the confined space of electrical cabinets, and form three-dimensional connections.

Process: The punched copper busbar is transported to the bending station. The bending mechanism typically consists of an upper bending blade (punch) and a lower bending die (die). The copper busbar is placed on a V-shaped lower die. The upper bending blade, driven hydraulically, moves downward, pressing the copper busbar into the V-groove of the lower die, causing plastic deformation and achieving the desired bend angle. Technical Key Points:

Compensation Calculation: The CNC system automatically compensates for angles based on the material’s elasticity (springback), ensuring that the actual bending angle matches the programmed angle.

Complex Bending: By replacing the upper and lower molds, various complex forming operations such as multi-angle bending, embossing, and flattening can be accomplished. Advanced equipment can even perform multiple bends in three dimensions.

Step 5: Unloading and Inspection
The finished copper busbars are automatically received by a support rack or robotic arm at the rear of the machine and placed in the finished product area. Operators use calipers, angle rulers, and templates to inspect the dimensions, apertures, and angles of the first and sampled parts to ensure they meet the drawing specifications.

III. Summary of the Advantages of CNC Three-in-One Processing Machines

Compared to traditional, decentralized, and manually operated, single-function machine tools (shearing machines, punching machines, and press brakes), CNC three-in-one machines offer revolutionary advancements:

1. High Efficiency: Integrating three functions into one, they enable complete processing in a single clamping operation, eliminating the time required to transfer workpieces between different machine tools, repeatedly position them, and re-clamp them, thus increasing production efficiency severalfold.
2. High Precision: Full CNC operation eliminates human error, ensuring product consistency and interchangeability, making it particularly suitable for mass production.
3. Low Labor Intensity: The high degree of automation reduces operator skill requirements and significantly reduces labor intensity.
4. High Flexibility: By changing programs and molds, the system can quickly adapt to the processing of products of varying specifications and shapes, achieving rapid response times.

Conclusion

From an ordinary copper busbar to a sophisticated, dimensionally precise busbar, the CNC three-in-one copper busbar processing machine perfectly embodies the essence of modern intelligent manufacturing. Through digital instructions, it drives the machine tool to accurately and orderly perform a series of actions such as shearing, punching, and bending, efficiently and accurately converting design drawings into high-quality physical products, providing a solid foundation for the safe and stable operation of power equipment.

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