BROADCASTS.com

The larger the batch runs, the more important cycle times and tooling costs become. Nowhere is this more pertinent than the automotive industry where the properties of both the machine and cutting tool need to be optimised for the chosen process.

MAPAL works with a machine tool builder to optimise this philosophy. The specialist machine construction company places the workpiece and its machining process at the centre of development and devises a solution perfectly designed for the process. As Meinolf Wolke, Sales Team Leader at ELHA-MASCHINENBAU Liemke KG (ELHA) in Hövelhof says: “We have a unique approach to customer inquiries. We take all technical and economic requirements into account and decide whether an existing machining concept can be used for the process or whether an individual, application-specific construction is required.

Meinolf Wolke explains: “As well as providing the machine, we offer services from process development to automation. The machining tasks are as unique as the parts. A lot of complex machining work can be achieved with standard tools. But that often comes with drawbacks in terms of cycle times, quality, and cost-effectiveness, particularly when large quantities are being produced,” adds Alexander Wiesner, Technical Advisor at MAPAL.

“During the tool design phase, it’s essential to determine the necessary parameters for the process,” says Wiesner. To design the process in the best possible way, MAPAL often makes prototype tools that are used to carry out extensive tests with the part. “That helps the equipment manufacturers design the machine with the values identified during testing,” continues Wiesner. He says that MAPAL has had a long-standing partnership with ELHA in this area. One example is machining automotive OEM suspension arms with solid carbide drills.

“We were dissatisfied with the solution for drilling aluminium suspension arms,” remembers ELHA’s Friedhelm Dresmann. The company was using brazed PCD tools. The disadvantages were the high power requirement and the insufficient durability of the PCD edges on the solid drill step. ELHA turned to MAPAL who developed a hybrid tool. The tool tip is equipped with three-bladed, CVD-diamond coated ISO-indexable inserts. The fitting is machined using brazed PCD cutting edges on the second step of the tool.

MAPAL tested the new tool and in addition to the lower indexable insert costs, the positive blade geometry meant that less drive power was required. What’s more, the previous solution produced long metal chips that were no longer an issue. The indexable inserts at the tip of the drill that are under significant stress, can be quickly replaced to reduce maintenance costs. The suspension arm manufacturers’ production costs for each drilled bore were reduced by over 50%.

Another customer required a deep hole drill for machining stainless steel forged components. “This customer is a manufacturer of high-pressure fuel-supply distributors for petrol engines. This requires drilling deep bores in narrow, forged, stainless steel blanks,” says ELHA Project Leader Jörg Rodehutskors.

The difficult to machine job has a 300mm deep bore and the drill needs to experience as little axial deviation as possible, otherwise, the wall that experiences high pressure will fall below the required minimum thickness. Previously, the bores were machined in a separate, single-spindle machines with a single-flute deep hole drill. To optimise the processes, the customer asked ELHA for a solution with multiple spindles and parts leaving the machine finished.

MAPAL provided a drill with less deviation, less wear and faster cycle times. MAPAL developed a double-edged solid carbide drill designed to meet the requirements. With application parameters of Vc = 90m/min and f=0.5mm, the new tool life is 80m, three times longer than before.