Whether it's analyzer-prepared labware, freshly washed towels and bed linen or gleaming dishes: With its Professional series for industrial customers, Miele offers high performance and durability in its machine designs. What is special about the Professional series is that the company's service begins even before the appliance is delivered to the customer. Thanks to a careful needs analysis and well-founded capacity calculations - combined with individual 2D and 3D room and process planning as well as detailed profitability calculations - the specialist develops specific problem solutions in dialog with the customer. The result is a needs-based system solution that guarantees reliable, smooth processes.

Even the largest mountains of laundry can therefore be accommodated in the large-capacity drums of Miele Professional washing machines. A capacity of 110 liters requires a secure drum design. Miele ordered a rotary transfer machine from a manufacturer of special machines and production equipment in order to reliably and safely join the two components, the drum base and drum shell, made of stainless steel sheets. The sheet metal processing and joining technology specialists from Tox Pressotechnik were brought on board for the task of joining the stainless steel sheets. After analyzing the requirements and the general conditions, they proposed the use of the company's patented round-point sheet metal joining process and designed a complete solution that could be integrated into the rotary transfer system as a ready-to-connect subsystem by the special machine manufacturer.

Connected with 97 round points

The subsystem comes in the form of a ready-to-use clinching device and is based on the modular Tox construction kit. The modular system consists of two CRH machine tongs with HZO hydraulic drive cylinder, the round-point tool set (punch and die) for clinching, an SP spraying device for oiling the clinching tool and the CEP process monitoring system for quality assurance. All components are made by Tox Pressotechnik. The machine tongs have a notch depth of 35 millimetres and an opening of 49 millimetres and are designed for press forces of up to 100 kilonewtons. The two components, drum base and drum shell, are joined by clocked setting of 97 Tox round points with a diameter of 8 millimeters. Clinching is carried out with a press force (including hold-down force) of 75 kilonewtons. The die depth is 1.2 millimetres and the control dimension X, the residual base thickness in the clinching point after joining is 0.85 millimetres. Each clinch point results in enormous head tensile/shear tensile strengths of 2,300 newtons and 2,700 newtons respectively, with process monitoring ensuring absolutely reproducible and documented joint quality.

The CRH machine tongs have a hydraulic drive cylinder and are designed for pressing forces of up to 100 kilonewtons. (Image: Tox)

The Tox-Clinch system as a ready-to-connect and ready-to-operate subsystem resulted in economic and time benefits for both Miele and the special machine manufacturer. The end customer benefited from the process know-how for sheet metal connections and received a complete solution that was tailored to their needs and worked reliably. And the special machine manufacturer was able to concentrate on the design and construction of the rotary transfer system and only had to integrate the subsystem. Thanks to the consistent use of standardized mechanical engineering, drive, peripheral, control and process monitoring components from the Tox modular system, special machine construction could also be carried out cost-effectively. ee