斷續切削에 있어서 切削抵抗과 工具壽命에 關한 硏究

梁均懿,남궁석 충남대학교 공업교육연구소 1980 論文集 Vol.3 No.2

The cutting resistance of grooved and non-grooved workpieces and the tool life under various cutting conditions was investigated experimentally with the use of a tool dynamometer. The results of this experiment are as follows : 1) The cutting force (principal and feed forces) increases with increasing depth of cut due to the force of the impact (force) between tool and workpiece in interrupted cutting. 2) The tool life of a P 20 cutting tool reduces with increasing feed cutting speed, and number of grooves. 3) The life of a P 20 tool is exceedingly short by comparision to the tool life of a H.S.S. tool in proportion to the increase of number of grooves.

旋削에 있어서 不均質被削材의 切削抵抗에 對하여

梁均懿,辛泰碩 충남대학교 공업교육연구소 1979 論文集 Vol.2 No.1

This paper describes that the cutting resistance of non-homogeneous workpiece siuch as mild steel having 6-4 brass fitted on 6 parts of grooved mild steel in turning operations with various cutting conditions by using tool dynanometer was investigated experimentally. The three components of cutting forces was recorded on the oscillograph, the size of workpiece was 50 ㎜ø × 300 ㎜ and Chemical composition of tool was w(18%) - Cr(4%) - V(1%). The results of this experiment are as follows; (1) The cutting forces increase with increasing depth of Cut, and feeds. (2) The cutting forces ( principal forces, feed forces) increase little by little till cutting velocity 60m/min, but the cutting forces increase rapidly from cutting velocity 60m/min to 110m/min and decrease from this point continously.

NC 가공을 위한 Ferguson 곡면의 오차 해석에 관한 연구

梁均懿,張鐘聲 全北大學校 1990 論文集 Vol.32 No.-

Sculputured surface are widely found in car body, ship hull and air plane parts. This paper covers computer-aided design of soulptured(or free-form) surface ; surface interpolation methods ; methods of generating CL-data for the machining of 3-D sculptured surface. The purpose of this paper is aimed to express how much we could show the real surface accurately comparing with the Ferguson surface used so many times, which is abtained from the 3-D point data through engineering calculation.

실험계획법을 이용한 대형 사출물의 사출성형 해석과 검증에 관한 연구

이형수,이희관,양균의 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis

Solid Modeling 기법을 응용한 복합곡면 가공에 있어서 공구간섭 제거

장동규,조시완,양균의 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.2

Compound surface modeling is widely used for die cavities and punches. A compound surface is defined in 3-D space by specifying the topological relationship of several analytic surface elements and a sculptured surface. A constructive solid geometry scheme is employed to model the analytic compound surface. the desired compound surface can be accomplished by specifying topological relationships in terms of boolean relations between primitives and the sculptured surfaces. Additionally, a method is presented for checking and avoiding the tool interference occurred in machining the compound surface. Using this method the interference of concave, convex, and side region can be checked easily and avoided rapidly.

Insert type 총형공구 여유각 영향에 따른 베어링 Rubber Seal 금형의 가공성 평가

Li, Li-Hai,김연술,김도형,양균의,문상돈 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

Formed insert type tool satisfy both the surface roughness and geometric accuracy, so that cutting edge of formed tool can duplicate final feature. For experiment, the formed tools with various clearance angles are machined. And the tools are evaluated with respect cutting force, flank wear and surface roughness to optimistic condition.

대장내시경 전처치제로서 Sodium Phosphate 와 Polyethylene Glycol 용액의 전향적 비교 분석

이헌경,김승용,홍원선,민영일,정훈용,김해련,정성애,김석균,심기남,양석균,박의련,조문경 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.3

Background/Aims: Although some authors have suggested that sodium phosphate (NaP) is more effective than polyethylene glycol (PEG) in bowel cleansing, there has been no crossover study proving the superiority of NaP over PEG in bowel cleansing and patients' compliance. The aim of this study was to compare the two solutions for colonoscopy, PEG and NaP, through crossover design with regard to patients' compliance, cleansing ability and side effects. Methods: Thirty patients underwent two separate colonoscopies for colonic polyp(s) with PEG and NaP, respectively. Before and after bowel preparation, blood pressure, body weight, and serum biochemical parameters were measured in all patients. In addition, a detailed questionnaire was used to assess side effects and the patients' preference. The presence of bubbles, types of residual stool, and overall quality of colon cleansing were assessed by one endoscopist blinded to the type of preparation used. In each colonoscopy, two biopsy specimens were taken at rectum. Results: In the NaP group, but not in the PEG group, there were significant changes in several biochemical parameters including sodium (+3.0±3.0 mEq/L), potassium (-0.3±0.3mEq/L), calcium (-0.5±0.5 mg/dL), phosphorus (+3.9±2.2 mg/dL) and osmolarity ( +10.1±9.3 mOsm/kg) after bowel preparation. In addition, the degree of body weight change was greater with NaP (-2.2±2.3 kg) than with PEG (-1.2±2.0 kg) (p=0.06) and the formation of bubbles that disturb luminal observation was more frequently found in the NaP group (p$lt;0.01). There was no difference, however, in the type of residual stool and the overall quality of bowel preparation between the two groups and no significant mucosal change was noted after bowel preparation in both groups. Moreover, PEG was found to be more difficult to take than NaP (p$lt;0.05) and among the 30 patients, 26 (87%) preferred NaP, while only two favored PEG (p$lt;0.01). Conclusions: We conclude that NaP can replace PEG at least in patients with good general condition. Further studies to decrease the incidence of bubbles and to establish subgroups suitable for NaP are needed.

A Study on the Modeling and Machining for the Sculptured Surface

Yang, Gyun-Eui,Kong, Young-Sig 全北大學校 1994 論文集 Vol.37 No.-

본 논문은 항공기, 자동차, 선박 그리고 가전제품과 같이 심미적으로 자유곡면을 지닌 금형제품을 가공하기 위한 방법으로 국부적으로 곡면제어가 가능한 Non-Uniform B-Spline surface Algorithm을 이용하여 곡면을 모델링하고 또한 3차원 NC가공을 수행 할 수 있는 Software를 개발하였으며 그 실용성을 입증하기 위하여 pan모형을 택하여 모델링하고 NC가공을 성공적으로 수행하였다. 따라서 CAM시스템의 실용성을 입증하였다.

A Study on the Model of Burr Formation Mechanism

Yang, Gyun-Eui 全北大學校 1989 論文集 Vol.31 No.-

본 논문에서는 clay 절삭의 최종단계에서 칩생성의 특별한 상황으로서 2차원 절삭에서 rollover burr를 다루고 있으며 clay절삭의 관찰을 근거로 몇가지 가정하여서, 절삭의 종료단계에서 칩생성기구가 변화되고 있는것을 밝히고 있다. 즉 변이점에서 양의 전단각의 발생이 중지되고 음이 전단각이 발생함으로 burr의 개시, 진전 그리고 생성과정을 확인할 수 있었으며 이 관찰을 통하여 burr생성모델을 유도하였으며 더욱이 현장에서 이용될 수 있도록 전자현미경(SEM)내에서 실용되고 있는 동(Cu) 절삭실험을 수행함으로서 burr생성모델을 증명하였다.

Effect of Polar Organic Substance on Burr Formation in Orthogonal Cutting

Gyun Eui Yang,In Chang Cha 대한기계학회 1992 KSME International Journal Vol.6 No.1