Parameterization and Simulation of a Cooling Channel Cross-Section in Single-Lip Drilling

Öz

Deep drilling with single-lip drills (SDLs), especially in materials that are difficult to machine such as Inconel 718, results in very high thermomechanical stress due to the material properties. The process is mainly influenced by the tool geometry, cutting forces, chip removal, and the cooling lubricant. Due to the straight flutes of the tools, chip removal is only possible through the cooling lubricant. For this reason, there is a cooling channel inside the tool. By increasing the diameter of the cooling channel, a larger volume flow and higher pressure at the cutting edges can improve cooling and chip removal. Modern methods such as numerical simulation provide important valuable insights. In this study, the coolant distribution during drilling was numerically analyzed. The aim was to reduce thermomechanical loads, which has a positive effect on tool wear and friction load. For systematic optimization, a mathematical model was developed to describe the cross-sectional geometry of the SDL. Based on parameterized sub-geometries, transition conditions, and experimental average values for the feed force and torque, numerical modification was performed using an iterative simulation model that considered the material´s mechanical strength. The maximum possible enlargement of the cooling channel while maintaining the strength requirements was analyzed on a total of 30 models. The cross-sectional area achieved an increase of 45.5% compared to the initial geometry.

Anahtar Kelimeler

• Simulation
• Parametrization
• Mathematical model
• Cooling-channel
• Single-lip drilling

Tek agizli matkapda soğutma kanalı kesitinin etkisinin parametreleştirilmesi ve simülasyonu

Öz

Tek agizli matkaplarla (SDL) yapılan derin delme işlemleri, özellikle Inconel 718 gibi işlenmesi zor malzemelerde, malzeme özellikleri nedeniyle çok yüksek termomekanik gerilime neden olur. Bu işlem, esas olarak takım geometrisi, kesme kuvvetleri, talaş kaldırma ve soğutma yağlayıcıdan etkilenir. Takımların düz kanalları nedeniyle, talaş kaldırma işlemi yalnızca soğutma yağlayıcı ile mümkündür. Bu nedenle, takımın içinde bir soğutma kanalı bulunmaktadır. Soğutma kanalının çapını artırarak, kesme kenarlarında daha büyük hacim akışı ve daha yüksek basınç, soğutmayı ve talaş gidermeyi iyileştirebilir. Sayısal simülasyon gibi modern yöntemler, önemli ve değerli bilgiler sağlar. Bu çalışmada, delme sırasında soğutma sıvısı dağılımı sayısal olarak analiz edilmiştir. Amaç, takım aşınması ve sürtünme yükü üzerinde olumlu etkisi olan termomekanik yükleri azaltmaktır. Sistematik optimizasyon için, SDL'nin kesit geometrisini tanımlamak üzere bir matematiksel model geliştirilmistir. Parametreleştirilmiş alt geometriler, geçiş koşulları ve ilerleme kuvveti ve tork için deneysel ortalama değerlere dayalı olarak, malzemenin mekanik mukavemetini dikkate alan yinelemeli bir simülasyon modeli kullanılarak sayısal modifikasyon gerçekleştirildi. Mukavemet gereksinimlerini koruyarak soğutma kanalının mümkün olan en fazla genişletilmesi, toplam 30 model üzerinde analiz edilmiş ve hedef geometri DP15 ile elde edilmiştir. Kesit alanı, ilk geometriye kıyasla %45,5 artış sağlamıştır.

Anahtar Kelimeler

• Simülasyon
• Parametrizasyon
• Matematiksel model
• Soğutma kanalı
• Tek agizli matkap

Kaynakça

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