• 한국자동차공학회논문집
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• 제18권1호
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• pp.127-130
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• 2010

This paper deals with the formability of DP590 steel considering the strain rate. The strain hardening coefficient, elongation and r-value were obtained from the static and dynamic tensile test. As strain rate increases from static to 100/s, the strain hardening coefficient and the uniform elongation decrease and the elongation at fracture and r-value decrease to 0.1/s and increase again to 100/s. The high speed forming limit tests with hemi-spherical punch were carried out using the high speed crash testing machine and high speed forming jig. The high speed forming limit of DP590(order of $10^2$/s) decreases compared to the static forming limit(order of $10^{-3}$/s) and the forming limit band in high speed forming test is narrower than that in the static forming test. This tendency may be due to the development of brittleness with increase of stain rate.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.355-358
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• 2003

Recently, micro forming process technology have been developed since the size of machine parts become the crucial factor for minimizing of products in general electronic products. Most small machine parts consist of gear and rotation axis and the wear by mechanical contact is known as the primary factor for life reduction of high precision machine part. Lots of studies for mechanical wear and friction have been reported and many researches of MEMS technology have been studied recently. But just few studies for wear of micro or milli sized machine part have teen implemented. In this research, the wear equation is suggested according to the contact shape of axial part in micro or milli sized machine part. And wear analysis model which can predict the magnitude of wear through this suggested equation with numerical analysis program.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.620-623
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• 2002

Spinning has been used widely for the manufacture of hollow parts with rotational symmetry. With developing CNC machine, CNC machine center can be applied to the spinning processes. In this paper, a study on the development of CNC spinning technology without mandrel is carried out. The deforming process of the spinning process was simulated by DEFORM 3D to give basic design data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.88.1-88
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• 2001

The paper describes a new approach to the organization of an artificial brain for mobile multi-robot systems, where individual robots are not considered as independent entities, but rather forming together a universal parallel and distributed machine capable of processing both information and physical matter in distributed worlds. This spatial machine, operating without any central control, is driven on top by distributed mission scenarios in WAVE-WP language. The scenarios can be written on a variety of levels, and any mixture of them, supporting the needed system flexibility and freedom ...

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 제7회 단조 심포지엄
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• pp.85-91
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• 2002

Of all the many types of machine elements which exist today, gears are among the most commonly used. Many researches have been done to manufacture helical gears by cold forging and extrusion. Although cold forging and extrusion were applied to some bevel, spur, and helical gears, problems in connection with reducing forming load and tool life still make it difficult for the related methods to be commercialized. In this study, focusing on reducing load in forming helical gears, extrusion of helical gears by a two-step process is proposed. The process is composed of an extrusion step of spur gears used as preform and a torsion step of the preform to make helical gears. Upper-bound analysis for the two-step process is performed and compared with results of experiments. The newly proposed method can be used as an advanced forming technique to remarkably reduce the forming load and replace the conventional forming process of helical gears.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.529-530
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• 2006

Manufacturing industry is changing rapidly. Prototyping with rapid manufacturing is a part of every business in many companies and prototypes are used efficiently as a part of the production development process. Sheet metal forming has traditionally been a technology area where prototyping has been extremely expensive and efficient options for low volume have been limited. This paper describes the process for incremental sheet forming technologies to make the prototype for a brake dust shield of vehicles, which includes the remodeling method to make a base mold and tool path for sheet metal forming and 5-axes laser cutting machine to trim the prototype product.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.824-828
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• 2002

Of all the many types of machine elements which exist today, gears are among the most commonly used. Many researches have been done to manufacture helical gears by cold forging and extrusion. Although cold forging and extrusion were applied to some bevel, spur, and helical gears, problems in connection with reducing forming load and tool life still make it difficult for the related methods to be commercialized. In this study, focusing on reducing load in forming helical gears, extrusion of helical gears by a two-step process is proposed. The process is composed of an extrusion step of spur gears used as preform and a torsion step of the preform to make helical gears. Upper-bound analysis for the two-step process is performed and compared with results of experiments. The newly proposed method can be used as an advanced forming technique to remarkably reduce the forming load and replace the conventional forming process of helical gears.

• 한국정밀공학회지
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• 제12권4호
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• pp.5-18
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• 1995

공작기계는 금속가공 공업에 있어서 가장 중요한 생산수단의 요소이며, 공작기계의 발달없이 인류의 생활수준을 향상시킨다는 것은 생각도 할 수 없는 일이다. 선진국에서는 제조된 기계의 약 10%가 공작기계이며, 기계공업 노동력의 악 10%가 공작기계 산업에 종사하고 있다. 공작기계는 금속재료를 절삭(Cutting) 또는 연삭(Grinding)하여 원하는 모양, 치수 표면정도의 제품을 얻는 것이고 기계본체와 공구의 두부분으로 되어있어 동력에 의해 기계를 운전하고 절삭공구로써 가공을 한다. 국제 규격의 ISO에서는 '한 운동원에 의해서 작동하고 물리적, 화학적 또는 기타의 방법으로 성형해서 공작물을 생산하는, 수작업은 하지 않는 기계'라고 정의 하고 있으며 미국에서는 금속가공기계를 두가지로 나누어 정형형을 Forming machine이라 하고 절삭형을 Cutting machine 이라 분류하며 이 둘을 합하여 공작기계(Machine Tool)라고 부르고 있다.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.15-23
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• 2003

A feature-based inspection planning system is proposed in this research to develop more efficient measuring methodology for the OMM(On-Machine Measurement) or CMM(coordinate Measuring Machine) for complicated workpiece having many primitive form features. This paper is proposed solution that optimum inspection sequence of the objective features. The sequences are determined by analyzing the feature information such as the nearest relationship and the possible probe-approach direction(PAD) of the features, and forming feature groups. A series of heuristic rules are developed to accomplish it. Also, each feature is decomposed into its constituent geometric elements for inspection process, and then the number of sampling points, location of the measuring points, optimum probing path are determined.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.196-201
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• 2001

This study reveals the thin sheet metal process with multi-forming die that the name is progressive die, as a pilotless type, also high precision production part is made. They require analysis of many kinds of important factors, i.e. theory and practice of metal press working and its phenomena die structure, machining condition for die making, die material, heat treatment of die components, know-how and so on. In this study, we designed and constructed a multi-forming progressive die as a bending and drawing working of multi-stage and performed through the try out for thin sheet metal. Out of the characteristics of this paper that nothing might be ever seen before such as this type of research method on the all of processes of thin and high precision production part.