Multipoint Tool Research Articles

Analysis of Tool Wear Rate in Drilling Operation using Scanning Electron Microscope (SEM)

Hole making had long been recognized as the most prominent machining process, requiring specialized techniques to achieve optimum cutting condition. Drilling can be described as a process where a multi-point tool is used to remove unwanted materials to produce a desired hole. It broadly covers those methods used for producing cylindrical holes in the work piece. However, high production machining and drilling with high cutting velocity, feed and depth of cut is inherently associated with generation of large amount of heat and high cutting temperature. Such high cutting temperature not only reduces dimensional accuracy and tool life but also impairs the surface integrity of the product. In this case, high pressure coolant (HPC) is very effective to reduce temperature. When temperature is increased a large amount of tool wear appears at the drill bit. In this situation, high temperature either affects roundness of the hole or chip shape and color of chip. HPC is applied in the same direction as the drill bit. HPC has reduced temperature as well as improving roundness and also provide lubrication in the tool tip and surface interface.

Development of functional surface by nano-plastic forming

A new nano-fabrication process by a direct imprinting method, named as nano-plastic forming, is developed. Three types of diamond tools were used for nano-plastic forming test; a knife-edge type tool, a multi-point tool and a nano-structured tool. These tools were used to imprint structures on soda glass and quartz glass by using a specially designed nano-plastic forming device. Experimental results confirm that the nano-structures can be fabricated by the nano-plastic forming technique even for hard–brittle materials. Imprinted structures were analyzed by an SEM and FIB. Surface properties of nano-structured glass plates were evaluated by a friction tester and an optical transmittance tester. Results of friction test show that friction properties vary with pitch and depth of grooves. Also, results of optical test show that the tool geometry and forming conditions influence the wavelength dependence of optical transmittance. These results indicate that friction and optical properties can be controlled by nano-plastic forming technique.

MULTI-POINT MACHINING WITH ANTI-GOUGING AND SCALLOP HEIGHT CONTROL

Multi-Point Machining (MPM) is a tool positioning strategy for 5-axis machining of complex surfaces. A multi-point tool position results in tangential contact between the tool and the design surface at several points. By machining at several points on the tool simultaneously, material removal rates can be improved. In this paper several issues regarding multi-point machining are resolved. First, a much faster method for solving the equations governing multi-point contact is presented. Second, a method of estimating scallop height is described. This estimator makes it possible to produce constant scallop height tool paths. Finally a method of eliminating interference between the tool and the surface has been developed and integrated into the MPM tool positioning strategy.

Tool tip gouging avoidance and optimal tool positioning for 5-axis sculptured surface machining

This article deals with locally optimal cutting positions and cutting directions for tool tip gouging avoidance in 5-axis sculptured surface machining. In order to measure the quality of tool positioning, this paper suggests a new concept of 'machined region width', which does not have the drawbacks of 'machined strip width'. The method evaluates the optimal cutting position of a flat endmill or toroidal endmill, where optimality is with respect to the avoidance of tool tip gouging. It is based on a second-order Taylor approximation of the design surface and multipoint tool positioning. The implementation and some illustrative examples are discussed.

Multi-point tool positioning strategy for 5-axis mashining of sculptured surfaces

Multi-point machining (MPM) is a tool positioning technique used for finish machining of sculptured surfaces. In this technique the desired surface is generated at more than one point on the tool. The concept and viability of MPM was developed by the current authors in previous works. However, the method used to generate the multi-point tool positions was slow and labor intensive. The objective of this paper is to present efficient algorithms to generate multi-point tool positions. A basic multi-point algorithm is presented based on some assumptions about the curvature characteristics of the surface underneath the tool. This basic algorithm is adequate for simple surfaces but will fail for more complex surfaces typical of industrial applications. Accordingly, tool position adjustment algorithms are developed that combine the basic algorithm with non-linear optimization to achieve multi-point tool positions on these more complex surfaces.