• Title, Summary, Keyword: Cutting Stage

Search Result 299, Processing Time 0.042 seconds

A study on the 3-stage 3-dimensional guillotine cutting-stock problem (3차원 기로틴 3단계 자재절단 방법에 관한 연구)

  • 김상열;박순달
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • /
    • pp.276-279
    • /
    • 1996
  • This paper deals with the method providing an exact solution to the 3-dimensional guillotine cutting stock problem. We suggest a 3-stage sutting method using the property that cubic material has to be cut into 2-dimensional planes firstly. This method requires more stocks that the general guillotine cutting methods but can save work force. By using the 1-dimensional dynamic programming, we reduce the computational time and the memory requirement in the 3-stage guillotine cutting method.

  • PDF

Stability Analysis of a Micro Stage for Micro Cutting Machine with Various Hinge Type and Material Transformation (초정밀 가공기용 마이크로 스테이지의 힌지 형상과 재질 변화에 따른 안정성 해석)

  • Kim, Jae-Yeol;Kwak, Yi-Gu;Yoo, Sin
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.7
    • /
    • pp.233-240
    • /
    • 2003
  • Recently, the world are preparing for new revolution, called as If (Information Technology), NT (Nano-Technology), and BT (Bio-Technology). NT can be applied to various fields such as semiconductor-micro technology. Ultra precision processing is required for NT in the field of mechanical engineering. Recently, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts. Therefore, in this paper, stability of ultra precision cutting unit is investigated, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed. In this paper, hinge shapes of micro stage in UPCU(Ultra Precision Cutting Unit) are designed as two types, where, hinge shapes are composed of round and rectangularity. Elasticity and strength are analyzed about micro stage, according to hinge shapes, by FE analysis. Micro stage in ultra precision processing machine has to keep hinge shape under cutting condition with 3-component force (cutting component, axial component, radial component) and to reduce modification against cutting force. Then we investigated its elasticity and its strength against these conditions. Material of micro stage is generally used to duralumin with small thermal deformation. But, stability of micro stage is investigated, according to elasticity and strength due to various materials, by FE analysis. Where, Used materials are composed of aluminum of low strength and cooper of medium strength and spring steel of high strength. Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

CFD Analysis on Flow Characteristics of Oil Film Coating Nozzle (유막 코팅 노즐의 유동특성에 관한 CFD해석)

  • Jung, Se-Hoon;Ahn, Seuig-Ill;Shin, Byeong-Rog
    • The KSFM Journal of Fluid Machinery
    • /
    • v.11 no.5
    • /
    • pp.50-56
    • /
    • 2008
  • Metal cutting operations involve generation of heat due to friction between the tool and the pieces. This heat needs to be carried away otherwise it creates white spots. To reduce this abnormal heat cutting fluid is used. Cutting fluid also has an important role in the lubrication of the cutting edges of machine tools and the pieces they are shaping, and in sluicing away the resulting swarf. As a cutting fluid, water is a great conductor of heat but is not stable at high temperatures, so to improve stability an emulsion type mixed fluid with water and oil is often used. It is pumped over the cutting site of cutting machines as a state of atomized water droplet coated with oil by using jet. In this paper, to develop cutting fluid supplying nozzle to obtain ultra thin oil film for coating water droplet, a numerical analysis of three dimensional mixed fluid Jet through multi-stage nozzle was carried out by using a finite volume method. Jet flow characteristics such as nozzle exit velocity, development of mixing region, re-entrance and jet intensity were analyzed. Detailed mixing process of fluids such as air, water and oil in the nozzle were also investigated. It is easy to understand complex flow pattern in multi-stage nozzle. Important flow Information for advance design of cutting fluid supplying nozzle was drawn.

Effect of Cutting Freqensy and Leavel of Nitrogen Fertilization on Carbohydrate Resreves of Reed Canarygrass (예취빈도 및 질소시비수준이 Reed Canarygrass의 저장탄수화물함량에 미치는 영향)

  • 서흥종;육완방
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.12 no.2
    • /
    • pp.89-97
    • /
    • 1992
  • This experiment was attempted to investigate the effects of growing stage, cutting frequency and the level of nitrogen fertilization on the change of carbohydrate reserves in reed canarygrass(Pha1aris arundinacea L.). The results obtained were as follows: The amount of carbohydrate reserves appeared to markedly decrease up to critical level after the cutting in hot and dry weather season. During the growing stage, the amount of carbohydrate reserves decreased just after the cutting and also during the period of flourishing elongation of reed canarygrass. However, it began to increase sharply from the end of September for wintering. Two cutting system showed the highest mean value(19.53 %) of carbohydrate reserves and those of three, five and four cutting system was 15.32 %. 14.73 %, and 14.60 % respectively. Reed canarygrass with no nitrogen fertilization resulted in 17.17% of carbohydrate reserve, however there was no singificant difference among various levels of nitrogen fertilization. In respect of regrowth. 3 cutting system showed the most effective cutting frequency, however 4 or 5 cutting system had a decreasing tendency of regrowth.

  • PDF

A Study on Selecting Method of Cutting Fluid using LCA (전과정평가를 이용한 절삭유 선택방법에 관한 연구)

  • 김종복;한영근
    • Proceedings of the Safety Management and Science Conference
    • /
    • /
    • pp.225-239
    • /
    • 2000
  • The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS(Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

  • PDF

A Study on Environmentally Conscious Manufacturing Processes using LCA (환경친화적 절삭가공방법에 관한 연구 - LCA적용)

  • 김종복;한영근
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • /
    • pp.625-629
    • /
    • 2000
  • The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS (Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

  • PDF

Laser Cutting of Thick Diamond Films Using Low-Power Laser (저 출력 레이저를 이용한 다이아몬드 후막의 절단)

  • 박영준;백영준
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.2
    • /
    • pp.140-144
    • /
    • 2000
  • Laser cutting of thick diamond films is studied using a low-power(10 W) copper vapor laser. Due to the existence of the saturation depth in laser cutting, thick diamond films are not easily cut by low-power lasers. In this study, we have adopted a low thermalconductivity underlayer of alumina and a heating stage (up to 500$^{\circ}C$ in air) to prevent the laser energy from consuming-out and, in turn, enhance the cutting efficiency. Aspect ratio increases twice fromm 3.5 to 7 when the alumina underlayer used. Adopting a heating stage also increases aspect ratio and more than 10 is obtained at higher temperatures than 400$^{\circ}C$. These results show that thick diamond films can be cut, with low-power lasers, simply by modifying the thermal property of underlayer.

  • PDF

A Study on Environmentally Conscious Machining Processes using LCA (LCA 기법을 통한 환경친화적 가공 방법에 관한 연구)

  • 한영근;김종복
    • Journal of the Korea Safety Management and Science
    • /
    • v.2 no.1
    • /
    • pp.141-159
    • /
    • 2000
  • The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS(Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

  • PDF

A Study on Development of Automatic Westing Software by Vectorizing Technique (벡터라이징을 이용한 자동부재배치 소프트웨어 개발에 관한 연구)

  • Lho T.J.;Kang D.J.;Kim M.S.;Park Jun-Yeong;Park S.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.748-753
    • /
    • 2005
  • Among processes to manufacture parts from footwear materials like upper leathers, one of the most essential processes is the cutting one optimally arranging lots of parts on raw footwear materials and cutting. A new nesting strategy was proposed for the 2-dimensional part layout by using a two-stage approach, where which can be effectively used for water jet cutting. In the initial layout stage, a SOAL(Self-Organization Assisted Layout) based on the combination of FCM(Fuzzy C-Means) and SOM was adopted. In the layout improvement stage, SA(Simulated Annealing) based approach was adopted for a finer layout. The proposed approach saves much CPU time through a two-stage approach scheme, while other annealing-based algorithm so far reported fur a nesting problem are computationally expensive. The proposed nesting approach uses the stochastic process, and has a much higher possibility to obtain a global solution than the deterministic searching technique. We developed the automatic nesting software of NST(ver.1.1) software for footwear industry by implementing of these proposed algorithms. The NST software was applied by the optimized automatic arrangement algorithm to cut without the loss of leathers. if possible, after detecting damage areas. Also, NST software can consider about several features in not only natural loathers but artificial ones. Lastly, the NST software can reduce a required time to implement generation of NC code. cutting time, and waste of raw materials because the NST software automatically performs parts arrangement, cutting paths generation and finally NC code generation, which are needed much effect and time to generate them manually.

  • PDF

Relationship between Specific Stubie Weight and Regrowth of Perennial Ryegrass (Perennial ryegrass의 그루터기 면적중과 재생과의 관계)

  • 이주삼;김성규
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.11 no.2
    • /
    • pp.90-96
    • /
    • 1991
  • This experiment was carried out in order to estimate the recovery days of root and stubble to the days after cutting, and contribution of specific stubble weight on the regrowth was examined using the relationships between the dry weight of shoot and yield components, and regrowth parameters by the days after cutting. The varieties examined were Maprima, Manhattan, Tove, Peramo, Caliente, Tempo and P-2 grown under individual plant basis. The results are may be summarized as follows: 1. Dry weight of root and stubble were recovered up to 13.5 and 11 days after cutting, respectively. 2. Dry weight of shoot(regrowth parts+stubble) was affected significantly by the varieties, stages of regrowth and variety x stage of regrowth. 3. The variety with tiller weight type showed higher average productivity of shoot than those of the variety with tiller number type. 4. Absolute growth rate(AGR) of shoot was correlated significantly with regrowth parts, stubble, root and weight of a tiller at the early stage of regrowth(up to 12 days after cutting), and correlated with regrowth parts, stubble, weight of tiller and stubble area at the late stage of regrowth(up to 20 days after cutting). 5. Contribution of specific stubble weight to absolute growth rate of shoot was different between the stages of regrowth. Thus, regrowth parts per specific stubble weight(RP1SSbW) and weight of tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the early stage of regrowth, and efficiency of specific stubble weight(ESSbW), regrowth parts per specific stubble weight (RPISSbW) and weight of a tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the late stage of regrowth. 6. Regrowth utilization rate(RUR) was one of the useful regrowth parameter to indicate the regrowth potential of grasses.

  • PDF