자유곡면 모형의 CAD/CAM 및 시뮬레이션

孟喜永 서울産業大學校 1987 논문집 Vol.25 No.1

In this paper, sculptured surface is represented by 3D point data and cutter path for NC machining is generated from the process planning of it. The following details are advanced in the course of their implementation. Cell-constructed geometric model is applied to the integration and interface of CAD, CAPP, and CAM uniformly. The end condition of surface boundary is expressed by tangent vector component of pivot circle. The regions which the cutter gouges large curvatured parts are restricted with the principal curvatured line. It is used variable feedrate estimation sheme to solve the cut-segmentation problem and to decrease the cutting time. As a results, it is developed software package, with which can conduct a CAD/CAM of sculptured surface model in the personal computer without economical burden.

곡면가공시 공구간섭에 따른 미절삭체적의 다단계 NC가공

맹희영,차지경 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

A new efficient intelligent machining strategy named the Steepest Directed Tree method is presented in this study, which makes surface model discrete with triangulation meshes and the cutter paths track along the tree directions. In order to formulate these algorithms practically, it is deduced the multi-stage machining approach of uncut volume caused by cutter gouging in the course of milling using flat end mill. It is systematized the checking process the cutter interference by grouping the 6 kinds of gouging types, which yields the environment of connectivity data lists including CL-data, and then the multi-stage machining strategy, that minimizes uncut area by continuously sequencing the generative subsequent CL-paths, is shamed to determine the second tool path for the next uncut area and to compose the operating multi-stage cutting processes. The completed machining system of curved surfaces is evaluated by testing the practical machining experiments which have various kinds of shape conditions.

곡면모형 Ball End Milling 의 모형화 및 기구해석에 관한 연구

孟喜永 서울産業大學校 1988 논문집 Vol.27 No.1

In this paper, ball end milling mechanism of curved surface model is analyzed to improve the cutting ability and to search for more refined tooling conditions. A general analysis procedure of cutting speed components on the rake face is established. It shows the properties that negative region of speed components occur in tool point and outside edge. And cutting operation angle determination stratagy is analyzed. It is also discussed relationship between geometrical cutting condition and cutting operation angle. The result of numerical procedurewill offer the fundamental materials to progress the cutting force, and stability analysis in curved surface ball end milling process.

계단형상 체적의 엔드밀 가공시 절삭력 변화 특성에 관한 연구

맹희영 한국생산제조학회 2013 한국생산제조학회지 Vol.22 No.3

This study analyzed thevariation in the cutting force when the cutting area of a terrace volume is machined, which is generally left after the rough cutting of a sculptured surface. The numerically simulated results for the cutting forces are compared with cutting force measurements by considering the theoretical prediction of the cutting area formation and specific cutting volume. The variation in the cutting force is measured using a dynamometer installed on a machining center for 19 different kinds of test pieces, which are selected according to the variation in the terrace volume factor, tool diameter factor, and cutting depth factor. As a result, it is verified that the cutting forces evaluated by the numerical analysis coincide with the measured cutting forces, and it is proposed as a practical cutting force prediction model.

NC밀링과정에서의 코너部 加工誤差에 관한 硏究

孟喜永 서울産業大學校 1986 논문집 Vol.23 No.1

The concerning cut error generated in NC milling process is not only a measure of servo system design, but important factor estimating the quality of manufactured goods. In this study, the models for contouring path, cutting dynamics in cornering cut and marching error generation mechanism are analysed dependently and compared with the experimental result. The comparison shows reasonable agreement and ascertains the fact that the effect of servo system reduces the total machining error magnitude in spite of contour error incerement. Also the machining erro profiles are obtained with respect to cutting condition, corner angles, and dwell time to accumulate data base for system design and NC programming

CNC선삭시 주축변위센서를 이용한 편심 가공오차와 절삭력 변화특성의 검출

맹희영,김성동 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

This paper presents the methodology for measuring eccentricity of the machined cylindrical part using CCS(cylindrical capacitance spindle sensor) signal in the CNC turning process. We use capacitance type sensor to take full advantage of averaging effect by using large capacitance area to encompass the whole side of a sensor. The intentionally proposed initial eccentricity is applied to the experimental test pieces, and their resultant relationships between CCS orbits and eccentricities are investigated. As a result, the possibility as a automatic detection apparatus for the CNC lathe is considered based on the linearities of CCS signal and magnitude of eccentricity of machined cylindrical surfaces.

CNC선삭시 주축변위센서를 이용한 편심 가공오차와 절삭력 변화특성의 검출

맹희영 朝鮮大學校 機械技術硏究所 2005 機械技術硏究 Vol.8 No.1

This paper presents the methodology for measuring eccentricity of the machined cylindrical part using CCS(cylindrical capacitance spindle sensor) signal in the CNC turning process. We use capacitance type sensor to take full advantage of averaging effect by using large capacitance area to encompass the whole side of a sensor. The intentionally proposed initial eccentricity is applied to the experimental testpieces, and their resultant relationships between CCS orbits and eccentricities are investigated. As a result, the possibility as a automatic detection apparatus for the CNC lathe is considered based on the linearities of CCS signal and magnitude of eccentricity of machined cylindrical surfaces.

측면 플래싱 장치를 이용한 형조 방전특성의 향상

맹희영,박근,김성동 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The discharge gap clearly is to order and to promote the improvement of processing feature of die-sinking electro discharge machining(EDM). If creation carbon, which generated by pyrolysis of EDM oil and processing pace power which is generated in between an electrode and a work piece, are overproduced, they will lower the processing speed and roughness of the surface. Therefore, it is gone through the flow analysis of EDM oil in order to improve the treatment of processing chips, which is an important problem by contriving a new flushing method. The condition of an electric discharge is not considered to be a progressing of processing. It is assumed that the flow of processing fluid is equal to the flow of processing chip, which is remaining in the discharge gap, and analyzing its correlation.

포인트 레이저 센서를 이용한 구면좌표계식 3차원 형상측정시스템 개발

맹희영,성봉현 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

Laser scanner are getting used for inspection and reverse engineering in industry such as motors, electronic products, dies and molds. However, due to the lack of efficient scanning technique, the tasks become limited to the low accuracy purpose. The main reasons for this limitation for usefulness are caused from the optical drawback, such as irregular reflection, scanning direction normal to measuring surface, the influence of surface integrity, and other optical disturbances. To overcome these drawback of laser scanner, this study propose the mechanism to reduce the optical trouble by using the 2 kinds of rotational movement axis and by composing the spherical coordinate to scanning the surface keeping normal direction consistently. So, it could be designed and interfaced the measuring device to realize that mechanism, and then it could acquisite the accurate 3D form cloud data. Also, these data are compared with the standard master ball and the data acquisited from the touch point sensor, to evaluate the accuracy and stability of measurement and to demonstrate the implementation of an dental tooth purpose system.

정밀공작기계용 에폭시-그래나이트재 구조물의 활용기술과 전망

맹희영 한국공작기계학회 2003 한국공작기계학회지 Vol.12 No.2