Schlote's history began in 1969 with a small workshop production facility in Harsum, where the company still has its headquarters. Today, the group comprises eleven companies with a total of 1,800 employees. The automotive supplier operates eight plants in Germany, with further production facilities in the Czech Republic and China. Its customers include car manufacturers, system integrators and foundries. The company generates 55 percent of its turnover with engine parts, 39 percent with transmissions and six percent with chassis.

There was already a successful collaboration with the company Trimet Aluminium at other locations to produce ready-to-install automotive parts from cast blanks. The contract awarded by an automotive supplier for a component that was to be produced in large quantities led to a joint venture between Schlote and Bohai Trimet in Harzgerode. The component manufactured here is a clutch housing made of die-cast aluminum. The supplier's automatic transmissions are supplied in a standardized version to several major car manufacturers, where they are primarily installed in vehicles with a displacement of up to two liters. The clutch bell housing connects the transmission and engine. The transmission side is the same for all clutch housings, while the other side is adapted to the respective engines of the car manufacturers. The differences are rather small, which is why this clutch bell is 99 percent identical for all car manufacturers supplied. Schlote currently produces 4,000 of these parts per day.

Clutch bell housing for automatic transmission

As in the entire automotive industry, the demands on the component are also high here. "The part is not just an adapter flange, it is the back of the gearbox. The bearing seats therefore require the highest precision," explains Sebastian Swiniarski, Group Manager Work Preparation at Schlote. Numerous holes with different tolerances have to be drilled into the component, which requires precision manufacturing in the range of thousandths of a millimeter. In addition to taps, reamers and various drilling tools from Mapal, PCD milling cutters are also used; the cutting tool is equipped with polycrystalline diamond inserts and creates defined rough surfaces for applying the sealing compound. The tools used were put to the test right from the start. Schlote carries out analyses to identify possible weak points and optimize production. As part of this continuous improvement process, Schlote and Mapal have been able to generate longer tool life, reduce tool costs and increase production volumes over the years. While a maximum of 3,600 parts per day could initially be produced, the possible limit today is 4,500 components without the need to purchase additional machines.

Optimization of deep holes with PCD milling cutter

The most recent optimization concerns deep bores for oil ducts, which are used to shift gears in the automatic transmission. Every month, Schlote uses the tool management system to evaluate which tools have been changed and how often. The deep hole drills were conspicuous every time. As these drills are also relatively cost-intensive, the company has addressed this issue in order to further reduce tool costs. Tool wear also brings quality aspects into play, as a blunt drill produces burrs when it emerges. Specifically, this involves two of five deep holes, which, with a diameter of eight millimetres, penetrate to depths of 180 millimetres and 141 millimetres respectively. They drill through the component from the side to the bearing seat in the middle. Previously, solid carbide tools were used for this, and Schlote achieved tool lives of up to 2,500 components. From 2,000 components, however, the machine's load monitoring system was already reporting tool wear and burrs were appearing at the exit opening.