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.

정전분말코팅 조건에 따른 3D 스캐닝 데이터의 민감도 특성 연구

맹희영,이주봉,김성민 한국전시산업융합연구원 2017 한국과학예술융합학회 Vol.29 No.-

surface to collect the 3D data using an optical 3D scanning device, like metal, rubber, glass materials. Currently, a developing solution is applied to eliminate the reflection of light of a material of a subject, but in the case of a developing solution, it is not only a consumable item but also a subject can be damaged, and it is difficult to remove it after coating. So that, an electro-static powder coating system is developed in this study that can be used as a substitute for the developing solution, and designed the system of the equipment in order to adsorb the electrostatic powder. The system of the electrostatic powder adsorption apparatus for three-dimensional photography is roughly classified into six parts, and includes an injection part for generating powder and voltage and a removal part for collecting and reusing powder sprayed on the subject It is a core part of the equipment system, and in other parts it is divided into a table of subjects, a control unit, a powder storage unit, and an air supply unit. After developing the equipment system, we analyzed and evaluated the data through 3D photography. Evaluation of the shape accuracy of the subject surface and the sensitivity characteristics of the three dimensional data were carried out. As a result, it was verified that the electrostatic powder coating method is more efficient than the developing solution application. In addition to being superior in terms of time and workers, the precision of three-dimensional data was more precisely known than with the developer coating. 백색광 3D 스캐너를 이용하여 금속이나 고무, 유리재질과 같이 매질 표면에서 빛이 난반사나 흡수 또는산란을 일으키는 표면 부위는 스캐닝 데이터의 손실이나 오류를 일으키기 때문에 데이터 수집이 어렵다. 이들 표면은 전통적으로 현상액을 도포하여 난반사가일어나지 않도록 스캐닝하고 있지만 부식이나 변색을유발시킬 수 있으며, 도포 후 완벽하게 세척할 수 없는 어려운 점이 있다. 본 연구에서는 이러한 문제점을 해결하기 위한 장치로서, 정전분말코팅의 원리를 이용하여 3차원 형상 측정을 위한 스캐닝 대상 표면에 정전기를 갖는 분말 입자들이 정전기의 힘으로 얇으면서도 고르게 코팅되도록 하기 위한 장치를 개발하였으며, 이 시스템을 이용하여 난반사 표면에 대한 3D 스캐닝 데이터를 얻을 때생기는 오류를 얼마만큼 줄일 수 있는가를 평가하였다. 피사체 표면에서 빛의 영향으로 데이터의 오류가 나타날 수 있는 3D 데이터의 민감도 특성에 대한 평가와 정전분말 코팅된 표면의 형상정밀도를 분석하였다. 무코팅, 현상액 도포, 정전분말코팅 등의 3가지 경우에 대한 스캔 데이터와 스캐닝 조건 등을 비교한결과, 금속 재질뿐만이 아니라 목재, 고무, 아크릴 등의 부도전체에서도 정전분말코팅의 조건이 3D 데이터수집의 민감도를 높여 주고 있으며, 빛이 흡수되거나고무 재질이나 투과되는 아크릴 재질에 있어서도 전반적으로 민감도는 우수해 짐을 밝힐 수 있었다. 또한 3D 스캔 데이터의 형상정밀도를 평가한 결과에 있어서는 일반적으로 코팅에 따른 형상정밀도의 향상은 투과성을 가진 유리 재질의 경우가 가장 적게 향상되고 있었으며, 금속의 경우보다는 비도전체의 경우가 그 차이가 크게 나타나지 않음도 밝힐 수 있었다

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.

최대경사방향 트리를 이용한 삼각형요소화 곡면모델의 NC 엔드밀링가공에 관한 연구

맹희영 대한기계학회 1995 대한기계학회논문집 Vol.19 No.9

A novel and efficient cutter path planning method for machining intricately shaped curved surfaces, called the steepest directed tree method, is presented. The curved surface is defined by triangular facets, the density and structure of which are determined by the intricacy and form accuracy of the surface. Geometrical form definition and recognition of the topological features are used to connect the nodes of the triangulated surface meshes for the successive and interconnected steepest pathways, which makes good use of end milling characteristics. The planetary cutter centers are determined to locate along smoothly changing paths and then the height values of the cutter are adjusted to avoid surface interference. Several machined examples of intersecting and intricate surfaces are presented to illustrate the benefits of the new approach. It is shown that due to more consistent geometry matching between cutter and surface(in comparison with the current CC Cartesian method) surface finish can be typically improved. Moreover, the material in concave fillets which is difficult to be removed by ball mills can be removed efficiently. The built-in positioning of cutter to avoid interference runs minutely in the sharp and discontinuous regions. The steepest upward movement of the cutter gives a stable dynamic cutting state and allows increase in the feedrate and spindle speed while remaining the stable cutting state.

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.

곡면 경계부 미절삭 체적의 잔삭 가공에 관한 연구

맹희영,임충혁,Maeng, Hee-Young,Yim, Choong-Hyuk 한국생산제조학회 2010 한국생산제조학회지 Vol.26 No.2

It is presented in this study a new efficient intelligent machining strategy, which can be used to remove the uncut volume at the boundary region of curved surfaces caused by cutter interference. The geometric form definitions and recognition of topological features of the surface triangulation mesh are used to generate cutter paths along successive and interconnected steepest pathways, that minimize the cusp height left after flat end milling. In order to machine the uncut volume gradually, the z-map cutter centers are adjusted to avoid cutter interference for the 6 kinds of avoidance types. And then, the generative subsequent paths are sequenced to determine the second step cutter paths for the next uncut volume. For the 2 kinds of test models with convex and concave surface region, the implemented software algorithm is evaluated by investigating the residual swelling of uncut volume for each machining step.

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.

연삭기용 직각 전자척의 자력특성에 관한 연구

맹희영,이용구 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

The new square electro-magnetic chuck, which is using for the clamping devices on a grinding machine, is developed in this study to improve the convenience of grinding works. The various kinds of structures are recommended to find the most adequate magnetic characteristics through the analytical approach using finite element methods. The analyzed results are retrofitted to solve the drawbacks of previous models step by step by considering the magnetic fields, strength and distribution of drag force, and thermal deformations of chuck. such as high parallelism and flatness. Finally the best recommended models is designed to satisfy the KS specifications required for the commercial magnetic chuck. The prototype chuck with this dimensions and structures is manufactured. For this final model, the experimental verifications are investigated whether the KS specifications are satisfied.

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.

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.