Takashi Nakae

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil Comparison of Cutting Performance with Dry Cutting

Abstract-This paper compares the cutting performance of minimal quantity lubrication (MQL) system with dry cutting in terms of flank wear, crater wear and finished surface roughness when using various kinds of cutting tools. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When using an uncoated tool, TiNand (Al, Ti) N-coated tools without coating on the rake face, and fully TiNand (Al, Ti) N-coated tools, MQL decreases the flank wear, crater wear and finished surface roughness compared with the wear and the roughness by dry cutting, particularly at the high cutting speed of 159 m/min. The reason suggested is the lubricating properties improved even with an extremely small quantity of cutting oil, which reduces the occurrence of deposited metal on the cutting edge. (2) With both the fully TiNand (Al, Ti) N-coated tools, the MQL system showed better cutting performance in terms of reduced tool wear and reduced finished surface roughness compared with that by dry cutting; in particular, the fully (Al, Ti) N-coated tool is suitable for an MQL system in hobbing.

A study examining the effects of water-miscible cutting fluids for end milling process of carbon fiber reinforced plastic

This study examined the improvements to the tool life and finished surface roughness by using water-miscible cutting fluids in carbon fiber reinforced plastics end milling. In cutting tests, it was found that the use of emulsion type, soluble type, and solution type cutting fluids improved tool life compared with the case of dry cutting. Specifically, significant differences in tool life were observed at a high cutting speed of 171 m/min. In addition, the finished surface exhibited a low level of roughness when the solution type cutting fluid was used, regardless of the cutting speed.This study examined the improvements to the tool life and finished surface roughness by using water-miscible cutting fluids in carbon fiber reinforced plastics end milling. In cutting tests, it was found that the use of emulsion type, soluble type, and solution type cutting fluids improved tool life compared with the case of dry cutting. Specifically, significant differences in tool life were observed at a high cutting speed of 171 m/min. In addition, the finished surface exhibited a low level of roughness when the solution type cutting fluid was used, regardless of the cutting speed.

Influence of water-miscible cutting fluid on tool wear behavior of various coated high-speed steel tools in hobbing

This paper deals with the influence of water-miscible cutting fluid on tool life (flank wear) compared with that with dry cutting and water-insoluble cutting oil in hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The following results were clarified. (1) The water-miscible cutting fluid used in the test prolongs the tool life for TiN-, TiAlN-, TiSiN- and AlCrSiN-coated tools in comparison with that obtained by dry cutting and water-insoluble cutting oil. (2) It was presumed that the tool wear decreases and the tool life is improved by the lubrication effect of the synthetic lubrication additive, mineral oil and sulfuric EP additive contained in the water-miscible cutting fluid, and also by the cooling effect.

Influence of Dimensions of Chip on Roughness of Finished Surface Produced by Hobbing (Fundamental Experiments Using Fly Tool)

©2013 The Japan Society of Mechanical Engineers 近年,機械加工において,切削性能の向上よりもむしろ作業環境の改善など環境問題に対する関心が高まって きており,環境に配慮したドライ加工やセミドライ加工技術の開発が行われている (1) ~ .ホブ切りにおいては, コーティング技術の発達により,ホブの耐熱性や耐摩耗性を向上させたコーティング膜が開発され,ドライホブ 切りが可能になり,環境保全および省資源の観点から強い関心が寄せられている.しかしながら,すべての歯車 材やホブ切り方法,ホブ切り条件,機械の剛性,熱影響,切りくず処理などに対応できるかを検討する余地があり, また,歯車の仕上げ面粗さや寸法精度などの点で多くの問題が解決されていない.これに対して,著者の一人は, ホブ切りを舞いツール切削にシミュレートし,ドライホブ切りに適した条件について報告している . 一方,セミドライ加工の代表である極微量油潤滑(MQL: Mnimal Quantity Lubrication)による加工は,環境に配 慮した加工法だけではなく,ドリル加工やリーマ加工など油剤が到達しにくい加工において良好な切削性能を発 揮し,またコストの面からも有利な加工法である.しかしながら,MQL によるホブ切りについての報告 (5)(6) があ る程度で非常に少ない.著者の一人は,ホブ切りを舞いツール切削にシミュレートし,MQL によるホブ切りの基 礎的研究について報告している . ホブ切りは平フライス削り形断続切削であり,その切削機構は複雑である.また,ホブの数刃が切削に関与し て歯溝部を削り取るが,各刃の切れ刃部で削り出される切りくず形状,すなわち切取り長さおよび厚さが異なっ Hobbing Fly tool cutting on milling machine 3-thread hob Feed of hob 4.0 mm/rev