When it comes to milling CFRP frame components for carmaker BMW, HG Grimme SysTech reveals how its CNC machines have set performance and quality benchmarks whilst keeping CFRP dust to a minimum.
In recent years, the use and processing of CFRP have become much more prevalent in the automotive industry. The use of high-quality lightweight materials, especially CFRP, also played a significant role in the development of a BMW model.
Machine tool manufacturer HG Grimme SysTech won a tender from BMW to provide machines for milling CFRP frame components. After a year of intense development work, the first machine of the G-DT-F(33-18)SB-2Z type began operating at the BMW Group plant in Landshut, Germany.
The Landshut plant uses the machine to produce entire side sections of a vehicle. As they are visible, the requirements placed on the quality of milling are high. Short production cycles are guaranteed by two machining heads which can work simultaneously on one component. To prevent any unnecessary downtime caused by unproductive periods and to increase the level of flexibility, for each axis group a changer for 26 tools, an additional quadruple angular head magazine with customer-specific tool management and multiple spare tools are used.
A focus on fine dust
The solution focused specifically on the huge amount of dust that is produced when machining fibre-reinforced plastics such as CFRP.
“When we were developing the machine, we together with the project team from the BMW Group were constantly thinking in particular about the fine dust that is produced during the milling process,” explains Bernd Settele, project manager at HG Grimme SysTech. “The objective was to guarantee very clean milling of CFRP.”
This is ensured by a newly developed, powerful machine for extracting the fine dust from several sides. 15 slide valves operate with great efficiency here by concentrating on the area immediately surrounding the milling process for extraction. The additional medium-pressure machine also filters the suspended particulate matter in the machine room. After the milling process, the operator’s insertion area is also scrubbed and exhausted again. HG Grimme SysTech says it ensures that the fine dust is also reliably filtered out of the air before any employee comes into contact with the component.
Industry 4.0 in focus
Special attention was paid to providing an extensive link to the BMW Group’s IT system and access to typical Industry 4.0 applications.
“Our solution enables complete traceability and precise evaluation of data – by providing accurate information including about wear, the general condition of the tools and the machine, for breakage control and a preview of upcoming maintenance,” states Settele. “When we were designing the BMW-specific HMI interface, we were also particularly keen to make it very user-friendly.”
Ergonomics was also a key focus in the machine room. It is not only almost dust-free, but also soundproof. A vertical rotary table allows shuttle machining and therefore very efficient feeding of the machine which reduces the amount of unproductive time. The rotary table can even be swivelled in the space of three seconds for jigs weighing more than a ton. Vacuum clamping technology and additional clamps that move automatically ensure that components are fixed securely during the milling process.
HG Grimme SysTech managing director, Wolfgang Grimme is very satisfied overall: “In supplying a milling system to the BMW Group, we have not only set high benchmarks for the performance and quality of the machine, but we have also managed to drastically reduce the impact on the surrounding environment from suspended particulate matter, for example.”