The problem addressed by the proposed method in sealing automotive window seals involves the continuous roll forming process, which is carried out on a roller press line using multiple pairs of rollers. A typical rolling production line consists of four main components: the feeding system, which loosens the coil and feeds the strip continuously to the forming machine; the forming machine itself, responsible for shaping the cross-section of the rolled part through multiple pairs of rollers (each pair consisting of upper and lower rollers mounted on horizontal shafts); the cutting system, which cuts the finished product to the required length; and the collection system, which automatically transfers the cut parts to the stocker without stopping the machine.
The forming machine is the core component of the entire production line, and the rollers play a crucial role as the molding molds for the sealing strips. Their shape and dimensional accuracy are key factors in determining the quality of the final product. For example, the middle window seal of a certain car model is made from a 155.5mm-wide and 0.7mm-thick SPCC steel strip, which is continuously rolled using an imported production line with 36 pairs of rollers. Due to the high cost of importing worn-out roller parts, local manufacturing and repair have become necessary.
To achieve this, we conducted a detailed mapping and reverse engineering of the existing rollers, even without original drawings or technical data. The complexity of the roller profile—composed of straight lines and circular arcs—combined with the fact that all 72 rollers are unique and require high hardness, posed significant challenges in both design and machining. As a result, traditional cutting methods proved ineffective, leading us to adopt polycrystalline cubic boron nitride (PCBN) tools, known for their high hardness and thermal stability, making them ideal for machining hardened materials like die steels.
For the CNC machining plan, we opted for numerical control processing due to its flexibility and efficiency, especially for single-piece production. The process involved rough and semi-finishing with hard alloy tools before heat treatment, followed by finishing with PCBN tools after quenching. This approach not only ensured precision but also reduced costs and development time.
In terms of programming, we used UG software for automatic image-based NC programming, allowing us to input tool paths, cutting parameters, and other essential data interactively. Tool selection was based on the specific requirements of each stage, with different configurations used for roughing and finishing. The cutting parameters were carefully set to ensure optimal performance and tool life.
Simulation of the NC program was an essential step to verify the feasibility of the machining process and prevent any potential collisions or tool interference. Both graphical simulation and dry-run functions were employed to check the tool path and confirm that everything was functioning correctly before actual machining began.
Through this comprehensive approach, the use of high-performance PCBN tools in the CNC machining of automotive window seals has proven to be an effective solution, significantly improving quality, reducing costs, shortening the development cycle, and enabling localized production and repair of critical components.
Coating Machinery,Bottom Spray Coater,Pharmaceutical Coating Machine,Tablet Film Coating Machine
Changzhou Bole Tech Co.,Ltd , https://www.boledrying.com