Aluminiumkompetenz für die Pneumatik

MAPAL harnesses its machining expertise from the mass production of aluminium components in the automotive industry for the production of critical components for pneumatics. Economical solutions for high quantities are needed in both industries. Cycle times and quality are key.

The story of the Aalen tool manufacturer MAPAL is strongly linked to fluid power. The company’s fine boring tools were already deployed in this area 50 years ago. Today, the fluid power market segment at MAPAL includes the areas hydraulics, pneumatics and process engineering. The material employed has a significant influence on the machining solution. Because liquids are under high pressure in hydraulics, casting and steel are used for the most part. Lightweight material like aluminium can be used as less pressure is needed for pneumatics.
 

Forces and movement are produced, controlled and efficiently transferred in pneumatics via air and gas. This takes place in valves and cylinders for the most part. Areas of application include machine engineering, logistics and medical technology.

MAPAL has identified two critical components in a housing for pneumatic valves and a pneumatic cylinder and has designed economic and high-precision machining processes for them. Due to their quantities of several million per year and the highest demands on process reliability, precision, and quality, both components are the perfect match for the tool manufacturer, which can draw on its aluminium machining expertise and product range for this purpose. The components are made of aluminium material with a small amount of silicon, which places high demands on the machining solution with respect to chip formation and removal. Particular attention is paid to avoiding burr formation or scoring: burrs in bores can have a significant effect on a valve’s functionality and even cause it to fail.
 

The cost driver in the production of valve housings is the middle bore for the spool – the spool bore – where tight surface, form and position tolerances must be precisely adhered to. The spool moves in this bore to control the airflow and in end effect move the pneumatic cylinder. MAPAL concentrates on providing customers with the most economical solution for their machining by means of tool combinations.

Solid carbide tools with special multi-cut technology and chip grooves for ideal chip control are used for stepped bores. Most tools are equipped with PCD blades due to the quantities and requirements. For contour machining, MAPAL combines PCD boring tools with milling applications. The tool begins with boring here and follows up with circular milling. Such combination tools mean fewer tools are required and machining and non-productive times are reduced. Multistage PCD combination tools also ensure the highest degree of concentricity for contour machining.
 

In der Schieberbohrung befinden sich mehrere Steuerkanten, die ein PKD-Zirkularfräser bearbeitet. Dessen Schneiden werden exakt auf das Kundenbauteil angepasst. Die Konturen fräst das Werkzeug in einem Arbeitsgang komplett aus, was für gravierende Zeiteinsparungen im Prozess sorgt. Das mechatronische Werkzeugsystem TOOLTRONIC ist eine hochtechnologische Alternative zum herkömmlichen Bearbeitungsprozess der Schieberbohrung mit PKD-Zirkularfräsern. Durch seine Flexibilität und konturfreie Programmierbarkeit lässt sich die Werkzeuganzahl deutlich reduzieren. So können auch Bauteilvarianten oder Änderungen am Bauteil einfach und ohne die Anschaffung neuer Werkzeuge umgesetzt werden.

Auch beim Pneumatikzylinder als zweitem Fokusbauteil steht das automatisiert gefertigte Gehäuse im Mittelpunkt, wobei die Herausforderungen in schwankenden Härteeigenschaften des Stranggussmaterials und hohen Bearbeitungsqualitäten liegen. Die charakteristischen Merkmale der beiden Fokusbauteile unterscheiden sich zwar, die Aufgabenstellungen für die Zerspanung sind aber sehr ähnlich. Folgerichtig setzt MAPAL auch hier auf cleveres Engineering. Dazu gehört unter anderem ein PKD-Kombinationswerkzeug zur riefenminimierten Komplettbearbeitung des Lagersitzes in der Kolbenbohrung mit Aufbohren, Zirkularfräsen und Fasen.