• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
• /
• pp.107-112
• /
• 2001

Control system for cutting piston used in vehicle that is one of the 3D shape cutting using CNC lathe is presented. In order to cut the hybrid piston shape using CNC lathe, defined piston shape and change into machine code. The control software was developed for the high speed piston shape cutting. In this paper, the performance of this software was evaluated practically. As a result, the evaluated cutting precision was quantitatively compared with theoretical precision. Also the productivity and the quality by using CNC lathe with control software were evaluated those by using profiling.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1243-1248
• /
• 2003

It is very important to measure linear motion accuracy of NC lathe as it affects all other parts of machines machined by them in industries. If the motion accuracy of NC lathe is bad, the dimension accuracy and the change-ability of works will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear motion of ATC(Automatic tool changer) on zx plane of NC lathe using two linear scales and the time pulses coming out from computer in order to get data at constant time intervals from the linear scales. And each sets of error data obtained from the test is discripted to plots and the results of linear motion errors are expressed as numerics by computer treatment.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
• /
• pp.193-199
• /
• 2000

Control system for cutting piston used in vehicle that is one of the 3D shape cutting using CNC lathe is presented. In order to cut the hybrid piston shape using CNC lathe, defined piston shape and change into machine code. The control software was developed for the high speed piston shape cutting. In this paper, the performance of this software was evaluated practically. As a result, the evaluated cutting precision was quantitatively compared with theoretical precision. Also the productivity and the quality by using CNC lathe with control software were evaluated those by using profiling.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1993년도 추계학술대회 논문집
• /
• pp.339-344
• /
• 1993

A study for a lathe to machine workpieces with noncircular corss-sections is presented. The noncircular cutting is accomplished by controlling the radial tool position synchronized with the revolution angle of spindle. A learning control algorithm is suggested for the toll positioning, of which the control performances are analyzed and simulated on a numerical computer that the effectiveness of the control is convinced. The learning control is tested on a NC-lathe which shows successful results.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1993년도 추계학술대회 논문집
• /
• pp.181-186
• /
• 1993

Thermal expansion of ball screw in the semi-closed loop type CNC LATHE introduces positioning errors directly along the travelling the axis. In this paper the thermal displacements of the ball screw were estimated by using macro variable. The estimated displacements of the ball screw were given to the ball screw of the CNC LATHE under the constant driving conditions were measured to examine the effectiveness of the compensation method. The results showed that thermal displacements of the ball screw could be maintained less then 6 .mu.m positioning accaracy while using this compensation.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 춘계학술대회 논문집
• /
• pp.641-645
• /
• 1996

Ball screws are used in the feeding system for transmission of driving force. The friction effect between bed and table, which can affect in accuracyin one dimension feeding and describe the dynamic feeding error, could be simplified as a specific model through experiments. The experiments for dynamic feeding errors were performed om tje NC lathe eith a ball screw. The errors in feeding were measured with respect to the variances of feed, spindle speed and motor current for feeding. A rotary encoder and a current sensor were installed with NC lathe.

• 한국정밀공학회지
• /
• 제15권7호
• /
• pp.104-118
• /
• 1998

In this paper, the motion of ballscrew and shape of workpiece are the main objective variables varying with load conditions. To verify feed mechanism in NC lathe, the monitoring system is designed and cutting condition variables are spindle speed depth of cut and feed. During machining, rotation number of ballscrew motion of ballscrew in direction to gravity center and cutting force are measured. After machining, the roughness of workpiece is measured.

• 한국생산제조학회지
• /
• 제19권6호
• /
• pp.859-866
• /
• 2010

Generally, a fixed type guide-bush system is installed during machining miniature work-pieces with high precision in the multi-task CNC lathe. But a conventional guide-bush system does not provide a constant clamping force under the condition of varying work-piece diameters. It is important to maintain a constant clamping force for guaranteeing machining precision. This paper proposes a new guide-bush system with a pneumatic clamping device for the CNC Swiss-turn lathe to keep constant clamping force with changes in work-piece diameters. Through performance tests, new clamping system developed in the study showed better machining precision at the cost of a small increase in the temperature of the system than conventional systems due to an increase in the frictional heat and a change in the heat transfer route.

• 한국정밀공학회지
• /
• 제30권12호
• /
• pp.1303-1312
• /
• 2013

We report an ultra-precision lathe designed to machine micron-scale features on a large-area roll mold. The lathe can machine rolls up to 600 mm in diameter and 2,500 mm in length. All axes use hydrostatic oil bearings to exploit the high-precision, stiffness, and damping characteristics. The headstock spindle and rotary tooling table are driven by frameless direct drive motors, while coreless linear motors are used for the two linear axes. Finite element method modeling reveals that the effects of structural deformation on the machining accuracy are less than $1{\mu}m$. The results of thermal testing show that the maximum temperature rise at the spindle outer surface is approximately $0.5^{\circ}C$. Finally, performance evaluations of the error motion, micro-positioning capability, and fine-pitch machining demonstrate that the lathe is capable of producing optical-quality surfaces with micron-scale patterns with feature sizes as small as $20{\mu}m$ on a large-area roll mold.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 추계학술대회 논문집
• /
• pp.349-350
• /
• 2008