The emergence of eco-friendly vehicles such as electric and hydrogen vehicles, together with the development of parts and materials linked with the functions of electrical equipment (electrical electronics), is directing the changes in mold trends.
With the accelerated transfer of universal mold technology to newly developing countries, higher value-added mold production based on high- precision, high-quality machining technology has become indispensable to securing sustainable competitiveness amid the current situation of fierce global market competition among developed countries with advanced technology.
In particular, machine tool manufacturers are expected to adapt to the rapidly changing mold machining trend, while taking the lead in simplifying the mold machining process and improving general machining processes, not to mention developing high-performance machines.
From this standpoint, it can be said that Doosan Machine Tools’ MP 6500 vertical machining center has been assessed as a machine that delivers the high precision, high value-added machining performance sought by the mold industry.
Executive summary
Molds are considered to have a huge influence on both the performance and safety of electric vehicle parts and IT precision instruments. Therefore, guaranteeing the highest possible level of machining accuracy is an essential aspect of mold production.
In addition, the demand for smart devices and small batch production is on the rise, thus requiring reduced mold machining time coupled with improved productivity. Also, the use of lightweight materials to reduce energy costs, coupled with the emergence of complex parts, has contributed to raising machining technology to the highest level.
Naturally, attempts to achieve multiple goals often result in some goals either lagging behind or being sacrificed in the process. Such a trade-off can also be found in the process of producing high-quality molds, usually because the surface roughness or machining quality of molds deteriorates if the cutting conditions are expedited in order to improve productivity.
For this reason, the mold industry is making concerted efforts to determine how to achieve the dual goals of ‘productivity’ and ‘quality’ simultaneously.
That being the case, what kind of machine tool is required to guarantee high-quality, high-precision machining? The answer lies in the MP 6500. The MP 6500 is equipped with a static pressure spindle that provides high-precision machining capability and enables superb cut-surface roughness through the adoption of high-speed/high-precision contour control designed to create optimal cutting conditions.
Furthermore, the MP 6500’s vertically symmetrical gantry type of structure provides operator convenience with its enhanced chip disposal and accessibility, while an easy-to-operate environment has been achieved by reducing the installation space.
What is the role of the spindle in high-speed, high-precision machining?
Explaining why the MP 6500 is regarded as a high-quality mold machining tool, Deputy General Manager Shin Sangcheol of Doosan Machine Tools was quoted as saying, “Surface roughness, i.e. the smoothness of the machined workpiece surface, pinpoint cutting accuracy, and the absence of left-over marks are the most important criteria in producing a high-quality mold.
The MP 6500 features a high-rigidity, low-vibration spindle structure that delivers tool rotation accuracy while minimizing rotating vibration”.
Usually, a preload is applied to the bearings to make the spindle rigid. However, the MP 6500 adopts the spindle structure of static pressure/preload structure. For this reason, it offers enhanced rigidity in the low-speed range and high-speed rotation compared to the conventional types of spindles, dramatically improving machine and tool service life as well as machining quality.
In particular, the MP 6500 allows the user to select a spindle capable of high-speed machining ranging from 20,000~40,000rpm, depending on the type of workpiece and the machining conditions.
Furthermore, it comes equipped with a dual-face tool locking system that securely fastens the tools to the spindle, thus boosting the service life of the tools and enhancing surface roughness during high-speed cutting.
Deputy General Manager Yoon Yeomain said, “As it is equipped with a static pressure spindle, the MP 6500 can provide superb surface roughness after finish cutting, as well as excellent rough-cutting capability, compared to rival machines in the same class.”
After introducing the machine, he went on to say that “The MP 6500 is best suited for recent high-quality machining trends that demand perfect machining capability and a high degree of machining accuracy.”
What are the solutions contributing to improving responding capacity to automation and productivity?
As a high-speed, high-precision mold machining tool, the MP 6500 features a stable gantry type of structure with reinforced rigidity that enables high-precision machining. In addition, the machine is equipped with solutions optimized for mold machinings, such as high-speed/high-precision contour control, tool monitoring, and optimal feed control, thus enabling mold machining automation.
Speaking of the machine, Deputy General Manager Shin Sangcheol was quoted as saying, “The MP 6500 is the machine to integrate all the powerful control functions developed by Doosan Machine Tools.
The control parameters, which are optimized for machine rigidity, can be preset to maintain stable machining accuracy even when the cutting conditions are expedited to raise productivity, while the machine’s look-ahead function for workpiece contouring helps to reduce the machining time.
Equipped with the latest version of DSQ(Doosan Super Quality), Doosan’s high-speed, high-precision contour control technology, the MP 6500 is quick to estimate a workpiece’s contours (look-ahead function) accurately, thereby further reducing the machining time.
In particular, the MP 6500 boasts the DSQ3 data server, an improved version created by adding a 600-block interpretation function to the DSQ2, thus enabling the storage of large-capacity machining programs. Also, the MP 6500’s DAFC (Doosan Adaptive Feed-rate Control), an optimal feed control technology, can provide a machining environment that enables machining capability using optimal feed control based on real-time spindle load detection.
What’s more, the MP 6500 is equipped with various solutions optimized for mold machinings, such as a ‘spindle static displacement compensation’ function that corrects changes of tool position caused by extension of the spindle shaft during high-speed rotation, and a ‘structure thermal error compensation’ function that corrects uneven deflection or swelling of the structure caused by changes in the external temperature by using multiple temperature sensors.
Also, the machine is able to maintain a higher level of accuracy thanks to the adoption of a roller type of linear guideway that increases rigidity, a linear travel system, a high-rigidity coupling, and a nut cooling system.
Deputy General Manager Shin Sangcheol said, “Pinpoint machining accuracy and machined surface quality are highly valued by customers who have already experienced the exceptional performance of the MP 6500. Recently, the demand for the MP 6500 has increased in the ultra-precision mold field.
Since the MP 6500 has proven its performance in the ultra-precision mold market, where ultra-modern materials are applied for its structure and the material of such structure, I am sure demand for the machine will continue to increase.”
Where can we find a new market for high-quality mold machining tools?
As explained earlier, the emergence of future cars, such as electric and hydrogen-powered automobiles, is being expedited, and the demand for smart devices is increasing exponentially, bringing about many changes in the mold machining industry.
In particular, not only the parts of conventional electronic IT devices but also eco-friendly auto components, increasingly require electric/electronic control functions, thus boosting demand for higher value-added molds, which in turn dramatically increases the need for high-quality, high-precision mold machining technologies.
Furthermore, with the introduction of the 52-hour working week for small and medium-sized companies with 50-300 employees at the beginning of this year, the need to improve such companies’ capacity to respond to automation, while reducing work preparation and non-cutting operation times, is one of the increase.
Deputy General Manager Shin Sangcheol said, “The level of tolerance applied to electric vehicles is higher than that for internal combustion. Considering the performance of the MP 6500, the machining of precision parts for electric vehicles should help to increase demand for the machine in the future car production field.
In fact, the MP 6500 could play an increasingly important role not only in the production of electric vehicles but also IT precision devices and parts for unmanned aerial vehicles.” Deputy General Manager Yoon Yeomin went on to say that “Since the MP 6500 provides an EOP (Easy Operation Package), which includes a large, ergonomically designed 15” monitor, and user-friendly setting and software functions for operation, the machine will contribute to improving the working environment and capacity to respond to automation.”
Meanwhile, the MP 6500 delivers specialty competitiveness not only for ultra-precision machining but also for mold machining for future cars and the machining of fine holes.
Deputy General Manager Yoon said, “The results of the fine pattern machining test showed that the MP 6500 completes machining successfully, whereas a competitor’s Z-axis spindle inflicts damage. The MP 6500 also shows excellent results in terms of precision. Recently, the MP 6500 also attracted a lot of attention among people working in the field of fine pattern machining.”
This content was originally published on the Doosan Machine Tools website.