01.11.2018
Kugelbahnfräsen an Gleichlaufgelenken für die Elektromobilität
Die Anfragen bei Neapco, einem international aufgestellten Zulieferer der Automobilindustrie, nach Komponenten für elektrisch angetriebene Fahrzeuge mehren sich. Auch ein aktuelles Projekt – eine Antriebswelle, die Neapco fertigt – kommt in einem solchen Fahrzeug zum Einsatz. Für die Hartbearbeitung des homokinetischen Außengelenks der Antriebswelle setzt das Unternehmen am Standort in Düren auf Kugelbahnfräser von MAPAL.
„Der Trend zur Elektromobilität ist auch mittlerweile bei Neapco erkennbar“, sagt Ahmet Simsek, der am Neapco Standort in Düren das Tool Management leitet. Bei dem Unternehmensstandort, der sich vor allem auf die Herstellung von Antriebswellen spezialisiert hat, seien schon einige Anfragen bezüglich Komponenten für elektrisch angetriebene Fahrzeuge eingegangen. Kein Wunder, beliefert Neapco doch viele namhafte Automobilhersteller mit Antriebswellen aus dem Werk in Düren und hat sich dafür optimal aufgestellt. „Seit kurzem sind wir erfolgreich nach der Norm IATF 16949 (Qualitätsmanagement in der Automobilindustrie) zertifiziert, da in einem stark wettbewerbsorientierten Umfeld ein hohes Niveau an Flexibilität, Effizienz und Qualität gefordert wird“, freut sich Simsek, „damit erfüllen wir nicht nur die Kundenerwartungen, sondern übertreffen diese auch.“
Die Zusammenarbeit von Neapco und MAPAL startete bereits lange bevor Industrie 4.0 und vernetzte Systeme Teil der Fertigungshallen wurden. „Es muss wohl Ende der 1980er Jahre gewesen sein, als die ersten gemeinsamen Projekte gelaufen sind“, versuchen Ahmet Simsek und Klaus Schwamborn, Gebietsverkaufsleiter bei MAPAL, gemeinsam zu rekonstruieren. „Seit einigen Jahren arbeiten wir auch im Bereich des Kugelbahnfräsens bei homokinetischen Gelenken, erfolgreich zusammen“, sagt Ahmet Simsek. Und so sei der Präzisionswerkzeughersteller beim aktuellen Projekt, einer Antriebswelle für ein elektrisch angetriebenes Fahrzeug, für die Hartbearbeitung der homokinetischen Gelenke die erste Wahl gewesen. „Durch unsere langjährige Erfahrung mit MAPAL, war das Unternehmen auch die erste Wahl für uns“, stellt Ahmet Simsek fest.
Contact angle within ± 5°
The production of the drive shaft started successfully at the beginning of 2018, and the production volume will be as high as 35,000 units in 2019. “We use the ball nose milling cutters from MAPAL to machine the ball raceways of what is known as the bell or axle spindle, for which strict tolerances are specified,” says Ahmet Simsek. It is important that this drive shaft joint transmits the torque with as little influence on the steering as possible, even in the case of large working angles on the drive gears of front-wheel drive vehicles. This is why all requirements regarding quality, dimensions and surface qualities must be observed in a process-consistent manner. For example, the contact angle must be within a tolerance of ± 5°.
The machining of the forged axle spindles on a machining centre of model EMAG VSC 250 Twin makes high demands on the machine as well as the machining technology. The C50 mod. material exhibits a hardness between 58 and 63 HRc after induction hardening. “Our ball nose milling cutters are used for the final hard machining of the raceways,” explains Klaus Schwamborn, who has been working with Neapco for many years. The tool, which has four soldered-in PcBN blades, removes between 0.2 and 0.4 mm of material.
MAPAL’s own high-precision connection
The tool is connected to the tool holder via MAPAL’s own HFS connection (Head Fitting System). The milling cutterhead is pulled into the holder with a high-strength clamping screw. The cutterhead is aligned via the short taper such that it is accurate to the micrometre and clamped against the face surface to ensure that the length dimensions in relation to the HSK face surface are observed. This highly stable connection also enables a high feed rate.
“The biggest challenge when designing the tool was to observe the tolerances in terms of a symmetrical contact angle and surface quality,” Schwamborn recollects. In the interest of cost-effective production, Neapco also places value on a long tool life. “On the basis of the profound knowledge we have gathered over many years, we tailored the tool to exactly fit Neapco’s application and requirements,” says Schwamborn. The tool geometry was adjusted precisely to the required values in terms of raceway clearance and the osculation of the balls that later lie between the inner and outer races.
“The biggest challenge when designing the tool was to observe the tolerances in terms of a symmetrical contact angle and surface quality,” Schwamborn recollects. In the interest of cost-effective production, Neapco also places value on a long tool life. “On the basis of the profound knowledge we have gathered over many years, we tailored the tool to exactly fit Neapco’s application and requirements,” says Schwamborn. The tool geometry was adjusted precisely to the required values in terms of raceway clearance and the osculation of the balls that later lie between the inner and outer races.
Optimum technical support
Within just a few days, the machining process was completely broken in at the start of 2018, and Neapco’s requirements were all met. Process-reliable production was ensured in no time at all. “MAPAL provided optimal technical support and assistance during the start of production,” confirms Ahmet Simsek. “Cooperative, open and trusting collaboration with our partners is incredibly important to us, and this is exactly the kind of relationship we have with MAPAL.” To maintain this relationship, Klaus Schwamborn as well as application engineers and product specialists from the precision tool manufacturer often visit Neapco at their location in Düren. Neapco has also set up a consignment warehouse with the MAPAL tools.
So it is not surprising that Neapco uses numerous other MAPAL tools for its manufacturing – mainly fine boring tools as well as drills and milling cutters made of solid carbide. “We also use the regrinding service and send our tools to the precision tool manufacturer for reconditioning,” Ahmet Simsek concludes.
So it is not surprising that Neapco uses numerous other MAPAL tools for its manufacturing – mainly fine boring tools as well as drills and milling cutters made of solid carbide. “We also use the regrinding service and send our tools to the precision tool manufacturer for reconditioning,” Ahmet Simsek concludes.
