Koichi Kikkawa

Theoretical Estimation of Machined Surface Profile Based on Cutting Edge Movement and Tool Orientation in Ball-nosed End Milling

Abstract This paper presents the theoretical estimation method of machined surface profile without actual machining in ball-nosed end miling. The fundamental simultaneous equations of identifying the cusp height at any point of a workpiece in the simulated surface have been successfully derived from the geometric relationship between the cutting edge movement and the normal line at the point. By the numerical calculation, the machined surface profile can be estimated and illustrated graphically. It was found that the maximum and minimum cusp heights exist in a narrow range of tool orientation less than 3 degrees near the normal direction.

Geometric Generating Mechanism of Machined Surface by Ball-nosed End Milling

Abstract This paper presents a new geometric estimation method of machined surface by ball-nosed end milling in sphere contouring. Firstly the geometric relationship between a cutting edge and a normal vector of the sphere has been formulated. Through the equation analysis, multi-crossing of them up to three times and the zigzag movement of the cutting edge have been found newly. Also the interference by a major flank was found too. Secondly a numerical calculation solver was developed by Newton-Raphson method. Thirdly the graphical display was realized by a CAD system. Through the observation of machined surfaces, the interference area was confirmed.

Research about Elastic Mechanism of Error Generation in Ball End Milling based in Geometric Analysis

This paper clarifies the elastic mechanism of error generation in ball end milling. At first geometric influence of the tool orientation on the thickness of undeformed chip in the ball end milling is analized precisely. Not only the shape of undeformed chip but also its thickness varies according to the tool orientations. So the authors have established a model of the elastic deformation of the ball end mill caused by the cutting force. As the verification of this model, the authors developed the experimental method for measuring the machining error on inclined surface in any direction and the cutting force is measured in same time. The cutting force on these experiments and the simulated results support the influence of tool orientations. Through the experimental results, the relationship between the tool orientation and the machining error has been clarified. The influence of tool orientation on the machining error has been discussed too. Finally the simple equation has been proposed that decribes the relationship between the geometric value of the cutting area and the elastic deformation of the ball end mill.

Experimental Study of Cutting Performance and Tool Wear in Dry Side Milling of Aluminum Alloy with DLC-Coated HSS-Co Cutter

This paper presents the experimental results of cutting performance and tool wear of a milling cutter in dry side milling of aluminum alloy A2017. The milling cutter consists of Co-bonded High-Speed-Steel matrix with Diamond-Like-Carbon coating (abbrev. DLC-coated HSS-Co cutter). The machining experiments were carried out under cutting speed of 63 to 189 [m•min-1] and feed of 0.08 [mm/tooth/rev], and the criterion of tool life was the generation of gauge and/or scratch on a machined surface. The experimental results support that the DLC-coated cutter in up cutting has good performance among four types of combination by the presence or absence of coating and the up/down cutting manner. They also showed that the tool life of DLC-coated cutter in up cutting under cutting speed of 157 [m•min-1] was corresponding to the cutting distance of 80 [m] with average width of flank wear 102 [μm] and that in down cutting was 60 [m] with 85 [μm]. In the range of cutting distance up to 100 [m], the resultant cutting force with the DLC-coated cutter was smaller than that with a non-coating cutter. In case of the DLC-coated cutter in up cutting under the cutting speed of 189 [m•min-1], a chatter vibration occurred during the initial cutting distance. In case of the radial depth of cut of 1.5 [mm], it lasted up to the cutting distance of 10 [m] and more.

Experimental Characteristics of Aluminum Alloys in Dry End Milling

This paper describes the cutting characteristics of aluminum alloys in dry end milling experimentally. The tested materials are A1050, A2017, A2024, A5025 and A7075. The cutter is a flat end mill of Co-cemented High Speed Steel with the diameter of 20 mm. Through the experimental results of side milling, the following three aspects have been found out. Firstly, as to the machining error, A1050 showed smaller machining error than 15 μm in the cutting speed rage from 62.8 m/min to 251.3 m/min. Other Aluminum alloys showed greater values. Secondly, as to the cutting force, those of aluminum alloys except A2017 were generally proportional to their material hardness. The cutting forces of A1050 and A5052 were constant over the whole range of cutting speed. Thirdly, as to the machined surface roughness, A7075 showed the smallest surface roughness among the all materials with its arithmetical mean roughness Ra under 0. 2 µm and with its maximum height of profile Rz under 1 μm. The machined surface roughness of A2017 varied widely. Through the visual inspection of machined surface, A2017 and A2024 showed picked surface as generated by a built-up edge. This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.

CAI System with Multi-Media Text Through Web Browser for NC Lathe Programming

A new Computer Aided Instruction (CAI) system for NC lathe programming has been developed with use of multi-media texts including movies, animations, pictures, sound and texts through Web browser. Although many CAI systems developed previously for NC programming consist of text-based instructions, it is difficult for beginners to learn NC programming with use of them. In the developed CAI system, multi-media texts are adopted for the help of users’ understanding, and it is available through Web browser anytime and anywhere. Also the error log is automatically recorded for the future references. According to the NC programming coded by a user, the movement of the NC lathe is animated and shown in the monitor screen in front of the user. If its movement causes the collision between a cutting tool and the lathe, some sound and the caution remark are generated. If the user makes mistakes some times at a certain stage in learning NC, the corresponding suggestion is shown in the form of movies, animations, and so forth. By using the multimedia texts, users’ attention is kept concentrated during a training course. In this paper, the configuration of the CAI system is explained and the actual procedures for users to learn the NC programming are also explained too. Some beginners tested this CAI system and their results are illustrated and discussed from the viewpoint of the efficiency and usefulness of this CAI system. A brief conclusion is also mentioned.