People often refer to CNC machine tools as the “industrial mother machine” in the equipment manufacturing industry, which is the most representative of the five-axis linkage machine tools. They play a crucial role in promoting national industrial strength and accelerating the development of manufacturing power.
Representing the highest level of machine tool manufacturing, the five-axis linkage CNC machine tool system is a key measure of a country’s ability to manufacture complex and precision parts.
It also reflects the level of technology and automation in national production equipment.
An important standard of the technical level of national production equipment automation.
With the development of industry, five-axis linkage CNC machine tools have become crucial. People consider them the most important high-precision machining equipment for key components.
People use these components in aerospace, marine, military, classified instruments, high-precision medical equipment, and other areas of processing and manufacturing.
As a complex and widely used technology, five-axis linkage CNC machine tools integrate computer control, high-performance servo drive, and precision machining.
Advantages
Compared to traditional three-axis CNC machine tools, they offer irreplaceable advantages.
(1) Machines can processing complex-shaped workpieces.
Five-axis linkage CNC machine tools can process complex-shaped workpieces that three-axis CNC machine tools cannot process. The machining process can effectively avoid tool interference.
For example, in the processing of aerospace components like impellers, blades, and whole leaf disks, five-axis machine tools offer significant advantages.
They allow the use of shorter tools, which enhances the rigidity of the system. Additionally, this approach reduces the number of tools required and helps avoid the need for specialized tools.
(2) High efficiency and precision
Compared to three-axis CNC machine tools, five-axis CNC machine tools offer several advantages.
They reduce the number of clamping and datum conversions. Additionally, they minimize the number of fixtures used, significantly improving both machining efficiency and accuracy.
(3) High flexibility and integration, and complete processing capabilities
Five-axis CNC machine tools offer high flexibility, high integration, and complete processing capabilities. These features make them an excellent solution for complex part machining in fields like aerospace and automotive.
They address challenges in machining accuracy and cycle time during the new product development process. As a result, they significantly reduce the development cycle and improve the success rate of new products.
At present, five-axis linkage CNC machine tools have become the hot spot and focus of the development of high-grade CNC machine tool industry in various countries.
Five-axis linkage of the basic structure of CNC machine tools
Most of the current five-axis CNC machine tools are “3 + 2” structure, that is, X, Y, Z three linear axes of motion plus respectively around the X, Y, Z axis rotation A, B, C three rotary axes in the composition of two.
Therefore, from the general direction of classification, five-axis linkage CNC machine tools have X, Y, Z, A, B; X, Y, Z, A, C; X, Y, Z, B, C three forms.
We can divide five-axis linked CNC machine tools into three main forms based on the combination of two different rotary axes.
These forms are: the double rotary table type, the rotary table plus pendulum head type, and the double pendulum head type.
Double rotary table structure of five-axis linked CNC machine tools
The rotary table structure of this five-axis linkage machine tool is the double rotary table structure of A-axis + C-axis.
The table set on the bed rotates around the X-axis, which we define as the A-axis. The working range of the A-axis is generally 30° to 120°.
The rotary table in the center of the table can rotate around the Z-axis, defined as the C-axis, which is capable of 360° rotation.
Therefore, by combining the A-axis and C-axis, the machine can machine the workpiece fixed on the table with a vertical spindle on all five faces, except the bottom face.
Five-axis CNC machine tool with rotary table and pendulum head structure
A-axis, B-axis or C-axis can be the rotary table and pendulum head of the machine tool, so the 5-axis CNC machine tool with rotary table and pendulum head structure can realize different combinations to adapt to different machining objects.
This setup offers the advantages that the machine spindle can machine flexibly and that it can machine large and complex workpieces by enlarging the machine table.
Five-axis CNC machine with double pendulum head structure
The pendulum head structure features a loose drawknife structure for the spindle. As a result, the size of the double pendulum head itself should not be too small, typically ranging from 400 mm to 500 mm.
Additionally, the design of the five-axis CNC machine tool provides a larger machining range due to the need for a wide range of motion for the double pendulum head.
These machines are generally gantry-type or movable beam gantry-type, with the gantry width typically ranging from 2,000 mm to 3,000 mm.
Currently, the more advanced double pendulum head type five-axis linkage machine tools generally use the “zero transmission” technology in the pendulum head structure.
The application of “zero transmission” technology in the rotary axis is a key solution to address the issues of rigidity and accuracy in the transmission chain.
Five-axis linkage CNC machine tool research status quo
Currently, developed countries in Europe, the United States, and Japan lead the research of five-axis linked CNC machine tools. These countries represent the highest level of development in five-axis linked CNC machine tools today.
With technological progress and the growing social demand for high-grade CNC machine tools, the CNC technology of renowned five-axis machine tool manufacturers is evolving.
The focus is on high-speed, high-precision, intelligent, composite, high-reliability, and environmentally-friendly developments.
Germany
SycoTec applies the 4015 DC-R-HSK63 high-speed precision spindle to five-axis CNC machine tool machining centers.
This upgrade expands the machine’s machining range from the original 0–24,000 r/min to 0–100,000 r/min, enabling five-axis ultra-high-speed precision machining.
The machine equips standard HSK-63 shanks, allowing for quick, frictionless tool changes.
This feature reduces machine stopping times, increases productivity and efficiency, and broadens the machining range of the machine.
Zimmermann designed the five-axis CNC machine and equipped it with a high-end three-axis milling head of M3 ABC with a curved guideway, adding one extra B coordinate, i.e., three different rotating coordinate heads of A, B, and C.
This five-axis CNC machine features excellent rigidity and a relatively compact structure. It also includes three different coordinate heads—A, B, and C—built-in.
This design increases the deflection range and ensures that the C-axis rotation process remains unaffected by the rotation of the other axes.
As a result, the design does not restrict the rotation process of the C-axis, which improves the accuracy of 5-axis linked CNC machine tools during machining operations.
France
The France-based SOMAB (SOMAB) company manufactured the DIAM five-axis machining center, which is highly versatile.
With just one clamping, it can perform turning, milling, boring, drilling, gear machining, crankshaft machining, on-line testing, and other composite operations.
This greatly enhances both the efficiency of machine tool processing and the machining accuracy.
USA
The United States’ Hurco (Hurco) company manufactured the offset spindle type i series five-axis machining centers. These machines use an integral electric spindle and are equipped with high-precision ceramic bearings.
The machining table can continuously rotate without any angle restrictions, which reduces beat time. This design allows for maximum tool feed and delivers superb performance when contouring complex parts.
The VF-6TR multifunctional 5-axis CNC machining center from Haas provides fully synchronized 5-axis motion and can position the workpiece at virtually any angle for increased machining flexibility.
Japan
The YASDA YBM Vi40 ultra-precision 5-axis CNC machine, made by YASDA Corporation (YASDA), features a rigid body.
It has an integrated bridge structure that ensures high-precision machining and excellent surface quality. This machine is specifically designed for mold and die manufacturing.
The VARIAXIS i series of multifunctional 5-axis CNC machining centers developed by Yamazaki Mazak Corporation (Mazak) is capable of machining the complex curved surfaces of large and heavy parts in a single setup.
The series applies the Done-in-One concept, which enables all machining, from raw materials to final products, to be completed on a single machine. This greatly reduces machining time and improves machining accuracy.
South Kore
South Korea’s Hyundai WIA (HYUNDAI WIA) exhibited the high-speed, high-precision five-axis vertical machining center XF6300.
This machine is designed with advanced mold products and high-precision machining capabilities. It features a high-performance built-in spindle that reaches 15,000 r/min.
By matching the spindle with high-precision, diversified spindles, the transmission of vibration to the axis is minimized. This enables the machine to achieve micron-level high-precision machining.
Italy
Italy’s FIDIA launched a five-axis high-speed milling vertical machining center. The high-speed spindle can reach up to 24,000 r/min, and it features an AC five-axis oscillating head.
This machine is mainly used for high-speed five-axis milling processing of automotive bumpers, lamps, interior molds, plastic molds, and other similar components.
Development trend and future outlook
Trend
From the above research status of five-axis linkage CNC machine tools, it is obvious to see that the development trend of five-axis linkage CNC machine tools today is:
(1) High-speed.
With the continuous development of machine tool technology, five-axis linkage high-speed CNC machine tools have made breakthroughs in their internal high-speed feed mechanisms and high-speed electric spindles.
As a result, the spindle speed of CNC machine tools and the range of feed volumes have significantly increased.
Among them, the linear motor-driven spindle speed has now reached 100,000 r/min.
The feed operation parts of the machine can achieve a rapid movement speed of 120 m/min. Additionally, the machine tool system’s cutting feed speed has reached 60 m/min.
These advancements effectively reduce processing time and auxiliary time, resulting in improved productivity.
2) Precision.
Five-axis linkage CNC machine tool machining accuracy is very high, with the development of computer-aided manufacturing (CAM) system, precision has reached the micron level.
In the processing of high-precision parts, the dimensional accuracy and shape accuracy of the parts can be guaranteed, avoiding machining errors.
3) Composite.
The five-axis linkage CNC machine tool was developed to adapt to the processing of polyhedral and curved surface parts.
With the advancement of machine tool composite technology, various composite machining centers have emerged.
These include five-axis milling and turning composite machining centers, boring, milling, and drilling composite machining centers, as well as milling, boring, drilling, and turning composite machining centers.
These machines can perform multiple machining operations simultaneously, significantly enhancing machining efficiency.
For example, when processing complex parts, milling, drilling, tapping and other operations can be carried out at the same time, thus shortening the parts processing cycle.
4) Intelligent.
With the development of artificial intelligence, big data, and the Internet of Things, CNC machine tools are rapidly advancing toward greater intelligence.
At present, the CNC machining process has achieved intelligent optimization and selection of machining parameters.
It also features adaptive control of the machining process, along with intelligent self-diagnosis and self-repair of faults. Additionally, it enables intelligent fault playback, fault simulation, and smart AC servo drives.
5) Flexibility.
Five-axis linkage CNC machine tools have strong adaptability when processing complex surfaces and other variable objects.
After a single clamping, multiple surfaces and angular processing can be realized on the workpiece.
This eliminates the need for repeated work type changes required by ordinary CNC machine tools.
It also avoids the transfer of parts between processes and the scribing of lines, ensuring a more streamlined and efficient workflow.
At present, CNC machine tools are moving towards the direction of unit and system flexibility.
Conclusion
Five-axis CNC machine tools are vital in modern manufacturing, excelling in precision and handling complex geometries across industries like aerospace and healthcare.
They surpass traditional three-axis machines by reducing clamping times and enhancing efficiency and accuracy.
Various designs, such as double rotary tables and swivel heads, offer versatility for different machining needs.
Innovations by industry leaders continue to drive advancements in speed, precision, and intelligent automation.
As demand for high-precision components grows, five-axis CNC machines will remain essential, pushing the boundaries of modern manufacturing technology.