• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.105-110
• /
• 2003

The hydraulic excavator has been a popular research object for automation because of its multi-workings and economic efficiency. When it works crane tasks, most of disasters happen. The objective of this paper is to design each components and to construct boom, arm, bucket circuit. These models modeled with AMESim show us change of variables and behavior of excavator. Simulation model will be used for simulator of excavator.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.10 no.1
• /
• pp.59-64
• /
• 2001

This paper is on a new cutting force model which includes the force caused by unbalance. The cutting under the different additional masses are measured with the spindle speed changed. The model is justified through correlation between simulation and experimental result.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.422-427
• /
• 2003

Sapphire have been ground by the ultra-precision surface grinder having a glass -ceramic spindle of extremely-low thermal expansion with various cup-type resinoid-bonded diamond wheels of #400-#3000 in grain size. Sapphire can be ground in the ductile mode. And also, the surface roughness and grinding conditions has been clarified. The smooth surface of Sapphire less than 1nm RMS, 1nm Ra can be obtained by the ultra-precision grinding without any polishing Process.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.4
• /
• pp.11-20
• /
• 1996

1994년 9월7일부터 15일까지 9일간 미국 Chicago에서 International Manufacturing Technogy Show(IMTS 94)가 개최되어 수십만명이 Show를 보기 위해서 세계 각국으로부터 모여들고 있었다. 필자도 그 중 한사람이었으며 Gidding & Lewis사의 전시 Booth에 도착했을 때 어떤 기계의 Demo 를 구경하기 위한 인파가 꽉 차 있는 것을 보았다. 먼 곳에서 보니 1969.7.20 미국에서 달에 쏘아올려 Neil Armstrong이 조종한 Apollo ll 우주선과 흡사한 모습의 기계가 보였다. 상하 두 Platform 사이를 6개의 다리로 지지되어 있고 상부 Platform의 하축에 공구의 Spindle이 부착되어 있었다. 이 기계를 VARIAX라고 부르고 미래의 공작기계가 이모양이 될 것이라고 설명하고 있었다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.27-33
• /
• 1999

In order to regulate cutting force at a desired level during NC lathe process, a feedrate override Adaptive Control Constraint system was developed. Nonlinear model of the cutting process was linearized as an adaptive model with a time varing process parameter. Performance of the ACC system was confirmed on the NC lathe equipped with the developed NC system through a large amount of experiment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.468-473
• /
• 2002

This paper presents the methodology for measuring eccentricity of the cylindricaliy machined part using CCS(Cylindrical Capacity Spindle Sensor) signal in the CNC turning process. In order to investigate the relationships between CCS orbits and eccentricities, the initial conditions for various eccentricity state and machining process is applied to the experimental strategy. AS a result, it is considered the linearities of CCS signal and magnitude of eccentricity of machined cylindrical surfaces based on the possibility as a automatic detection apparatus for the CNC lathe.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.6
• /
• pp.10-16
• /
• 2021

Drilling is a crucial process that takes up a significant amount of weight during machining operations. In addition, drill tip-type tools and related operations have been developed for manufacturing industries to achieve economic efficiency. In this study, SM45C carbon steel, widely used for machine structures, was utilized as the working material after quenching and tempering. Insert-tip types of carbide tools, such as TiN and TiAlN, were used as tool materials. Drilling conditions such as the spindle revolution, feed rate, step of cut, and tool diameter were used to measure roughness, roundness, and straightness using the orthogonal array table statistical method. The surface roughness, roundness, and straightness characteristics based on the conditions were analyzed using ANOVA. The results showed that the spindle speed and feed rate were the main factors influencing carbide insert-tip drilling under the same conditions as the experimental conditions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.87-94
• /
• 2002

In order to manufacture a precision mold/die by machining, users need high speed ＆ precision mold/die machining center. So, for development of this machine, we intend to use linear motor that is instead of ball-screw, servo-motor and coupling, high-speed spindle of pressurized air journal bearing and composite materials. In this paper we research column moving type and table moving type. The former is mainly piling 3 axes on one moving body, the latter is consist of two independent carriages. Both types are available to high speed & precision machine, but we finally draw a conclusion column moving type due to an advantage of high-speed control of linear motor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.329-334
• /
• 2004

This paper proposes Internet-based checking scheme for machine-tools with a variant CNC. Checking points defined in this research are classified into two categories such as structured point and operational point. The formal includes the vibration of bearing, temperature of spindle unit and another periodical management. And the latter includes oil checking, clamp locking/unlocking and machining on/off status. Through this research, for the global management of variant CNC machines interspersed with CAC and OAC in manufacturing system, the suitable environment for Internet-based checking of variant CNC machines was designed and the checking methods for CAC and OAC machines were compared with each other.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.449-453
• /
• 2000

In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to analyze the thermal characteristics under several operating conditions, experiments performed with the touch probe unit and five gap sensors on the vertical and horizontal machining centers.