It is only possible to economically mass produce workpieces by combining multiple processes in one process to minimize auxiliary time. This can be done with a combined tool. The combination tool can drill holes of different diameters, which can be used to mill end faces, mill countersunks, chamfers, reamings or turning threads when rotating. Combined tools are especially suitable for complex workpieces that require multiple tool series machining. It was originally changed after each drilling, chamfering or turning of the thread, but now it can be done in one setup. This significantly reduces the number of tools required to machine the workpiece and the space occupied by the corresponding magazine. A combination tool can replace 5 to 10 conventional tools. In the case of processing complex workpieces, the machining time is reduced by about 70% due to the shortened takt time, and the cost of purchasing the tool is thereby saved. However, the superiority of this versatile tool is far from simplifying tool management and reducing the cost of purchasing tools and inventory. Since all the cuttings are arranged on the mutually arranged cutters, the position between the blades is accurately determined, and the resulting high precision reduces the inspection cost and simplifies the quality assurance work.
With a combination tool, the machining accuracy depends on the tool itself. This is better than relying entirely on the accuracy of the machine. Therefore, this tool is more suitable for machining particularly precise workpieces. Although its original intention was designed for large and medium batch processing, it also appeared in the case of repeated small batch processing.
The range of combined tools has ranged from simple stepped drilling to highly complex, multi-part tools with various cutting materials for different production tasks. The so-called multi-technology tool is capable of drilling, chamfering, milling and milling threads in one process, or for hard and soft cutting, as well as roughing and finishing. Due to the high precision of the knives, it is significantly less than the machining allowance left for machining with two tools for finished machining. The result: improved surface quality and durability of the workpiece.
Modules with ultra-fine structure (HFS) can be assembled according to the needs of production. With a 3mm precision HFS interface, it can be combined into a tool made up of multi-segment modules. The machining allowance for finishing is only a few hundredths of a millimeter. The modular construction simplifies the re-grinding of the tool. The tool advantage of such a replacement module is that a module can be replaced simply, quickly and with high precision in the case of changing the workpiece. If necessary, the replacement can be completed even during machine working hours.
Today's universal machining centers combined with combined tools create the productivity that only a few special machines can achieve in previous years. Three technological innovations have broken through the constraints of high-productivity machine tools: spindles with high stability and minimal radial runout; precision HSK holders and tool materials and coatings for high-power cutting. In the last ten years, the technological progress in this field has been remarkable, and the development of technology has effectively improved the durability of the tool, and the combined tool has more practical significance.
In addition, due to the great development potential of cutting materials and coating technology, the application capability of the tool will be further improved. Another developmental force is dry cutting technology. Although people have long studied this technology, it needs further development to enter practical applications. Finally, the use of carbide tools with improved geometry, PKD tools and CBN tools enables micron-accurate machining, which further expands tooling applications.
A further trend is to develop tools that are oriented to the platform. For tool production, this means referring to the automotive industry's approach: making reasonable combinations or transforming cutting and functional modules based on changes in production tasks. The main advantage is that various special tools can be manufactured quickly and inexpensively. Another development trend is the development of tools based on mechanical principles. Solutions have been developed to fine-tune the tool and perform roughing and finishing operations.
Since it is necessary to tailor each work task, usually the combination tool is specially made. But their price is not so expensive compared to general-purpose tools, because only higher productivity is enough to make up for the extra cost of production. Of course, it is necessary to determine the size of the production batch according to the actual situation, it is worthwhile to use the combined tool. Those who have this intention are those manufacturers who not only need to provide tools, but also need to develop a complete production process plan based on user data.
