Design Matters – Maximizing Performance in Transfer Line Machines
In the age of modern manufacturing, industries demand fast and effective solutions for mass production, and transfer line machines are designed and equipped for this purpose. Transfer lines consist of several work stations with different types of tools for diverse machining operations such as turning, drilling, milling, and boring. Each station may include several spindles with cutting tools for machining different surfaces of a workpiece, which means that several dozen tools might be performing simultaneously.
Transfer line machines are robust and can be used only to produce specific items. With the growing demand for even higher mass-produced parts, transfer line machines have been widely adopted specifically for small cylindrical parts produced from rods. This phenomenon makes these machines highly popular.
The transfer line concept aims to induce manufacturing by applying the fastest and most economical methods. High performance depends in no small measure on effective tooling and finding an optimal tool is a task that requires cooperation between machine manufacturers, tool producers, and machine users. There is a direct correlation between the links of this coordination chain and ultimate operation efficiency - the closer the collaboration, the more effective the chosen tool will be. Continuous cooperation and communication with leading machine tool builders (MTB) has furnished ISCAR with a foundation of know-how and experience to improve development of cutting tools and tool holders for transfer line machines.
According to ISCAR’s MTB specialists, achieving success depends on the right tool design. Most of the tools are specially tailored and complicated due to the complexity of a machining process that features very tight cycle times. Combined tools maintain exact cycle times and reduce the number of stations required for a given machining process.
Often the tools are combined to perform several types of machining such as drilling, boring, countersinking, chamfering, spot facing, and more. These tools often include adjusting mechanisms. A combined tool must ensure comprehensive chip evacuation capabilities from multiple machining zones. This is a major requirement for the tool design.
Combined tools for drilling, trepanning and chamfering operations usually operate internal and external surfaces simultaneously. Here, the overall design has to ensure high rigidity to avoid vibrations caused by the specific shape of the tools that are required for machining several surfaces simultaneously, especially for those that have a complicated shape.
Drilling and internal slotting tool combinations void the need for an extra station, saving total cost and cycle time. With these types of combination, it is essential that the design prevents tool collisions between operations and facilitates good chip evacuation from internal areas.
Plunging operations with direct and back chamfering, for example, are generally performed in sequence using long tools; consequently the design requires enforced rigidity and vibration damping.
Selecting optimal cutting tool and tool holders for transfer lines usually requires specific tool dimensions dictated by the parameters of a work station, stroke limitation, and reliable chip evacuation to ensure non-stop production cycles. Cooperation between machine and tool producers is necessary for verification and validation of planned process and right tool selection, from the initial design to the run-off stage, and even to post-production optimization.
Tight tolerances can be achieved with mono-block tools combined with specially tailored tools that have different adaptations such as CAMFIX or HSK. Tools designed with adjusting mechanisms also enable tolerance precision, while allowing stability and rigidity of both the tools and the process.
Rotating and non-rotating shape forming tools equipped with ISCAR’s FTB, XNUW and PENTA inserts facilitate a reduction in cycle time by machining complicated profiles in a single pass.
Turning operations such as external turning, boring and reverse boring are often performed by linear axis machining perpendicular to the spindle’s centerline. This type of machining is commonly referred to as “U-axis, ” a term used for placing tools on special heads with complicated block systems and counterweight. These tools are either mounted on blocks or directly on the head.
Both concepts include integral and modular tools with CAMFIX, HSK, VDI or other adaptation types, as well as tailor-made tools developed according to customer request.
Mass and large scale manufacturers, principally from the automotive, oil and gas, medical industries, and the branches that produce miniature parts, are the main users of transfer lines. The long and fruitful cooperation between ISCAR teams and these customers has already resulted in the design, development, and implementation of productive and reliable tooling solutions. This model of a constructive partnership between customers and machine tool builders is especially applicable when planning tools for transfer lines, where the balance between productivity and cost per part is so important.