Take You Through the Current Status and Trends of New Cutting Tool Technologies

Cutting tool performance not only depends on the tool itself but also on factors such as the machine tool used, the connection between the tool and the machine, the tool holder system, the tool’s dynamic balance, and the tool safety monitoring system. The technology related to cutting tools has made new advancements with the progress of science and technology.

1. Tool Holder System in High-Speed Cutting

In the past, CNC machine tools, such as machining centers, primarily used the traditional 7:24 solid taper tool holder system. This tool holder relies only on the taper surface for connection, which results in lower rigidity between the tool holder and spindle. As spindle speeds exceed 10,000 rpm, the lack of rigidity becomes even more pronounced. For tool changers using ATC systems, the radial dimensions of the tool may change after each tool change, leading to issues with repeated positioning accuracy. To solve these problems, improvements have been made to the standard 7:24 tool holders. Inspired by the HSK tool holder, new 7:24 connection technologies have emerged in recent years, such as the three-point contact (3LOCK SYSTEM) and double-sided (BIGPLUS) 7:24 tool holders developed by Japan’s Nikken and Daishowa companies. Compared to the standard 7:24 tool holder, these offer higher connection rigidity and precision, making them suitable for high-speed cutting. They are also compatible with existing 7:24 tool holders and machine tools, representing the future direction of 7:24 tool holders. In addition to modifying the standard 7:24 tool holder structure, new HSK and KM tool holders are also being widely adopted.

The HSK tool holder is a new high-speed tapered tool holder with a dual positioning system that uses both the taper surface and the end face for location. The tool holder is designed to be compact with a short taper, which facilitates lightweight and high-speed tool changes. The end face positioning eliminates axial location errors, making high-speed and high-precision machining possible. This is also the development direction for domestic tool manufacturers. With the advancement of technology, the connection technology between high-speed tools and spindles will continue to evolve, leading to further improvements in new concept tool holders like HSK, KM, 3LOCK, and BIGPLUS. The current development direction for spindle and tool connection technologies is:

1. Adopting a dual-side positioning system.

2. High clamping accuracy, good holding rigidity, and compact structure.

3. Tool holders with balancing and vibration-damping devices.

4. Developing multifunctional and intelligent tool holders.

5. Dynamic Balancing Technology for Cutting Tools

For high-speed rotating tools, balancing and safety are significant issues. In high-speed spindle systems, any imbalance in a rotating body will generate centrifugal force. An unbalanced tool or tool holder will cause vibrations in the machine tool during high-speed cutting. Even a tiny imbalance in the rotating tool can generate substantial centrifugal forces during high-speed cutting, leading to irregular cutting forces. This can result in uneven wear, affecting both the machining precision and surface quality of the workpiece. It also reduces the lifespan of the spindle bearings and tools, and more importantly, it impacts the safety of high-speed cutting. Therefore, dynamic balancing of cutting tools is essential for high-speed cutting.

Currently, foreign companies have developed specialized dynamic balancing machines for cutting tools. Germany’s HAIMER and Italy’s CEMB companies have introduced vertical tool dynamic balancing machines that can automatically measure tool dynamic balance. The direction for the development of new dynamic balancing measurement instruments is to ensure accurate measurements, ease of operation, and powerful functionality.

3. Development of Tool Edge Passivation

Currently, most imported solid tools or indexable inserts have undergone edge passivation. After passivation, the micro-defects at the tool or insert edge are removed, effectively increasing edge strength. The tool life generally improves by 20% to 100%.