• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.139-142
• /
• 1995

Inconel 718 is one of the most difficut workpiece for machining, So it is necessary to evaluate the machining characteristics of Inconel 718 In this study, High speed machining of this material was carried out with Tin coated WC ball endmill and TiN coated HSS ball endmill. The cutting force and shape of machined surface and cip type were investigated according to variation of cutting speed,feed rate and depth of cut

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.15 no.3
• /
• pp.15-20
• /
• 2016

In this study, a numeric model for the prediction of ideal surface roughness in the rounded end mill was derived from the shape of the tool and feed per tooth. The model is compared with the well-known model of a ball and flat end mill. The ideal surface roughness was matched to the actual surface roughness by the linear equation, from which the empirical constant should be gathered from the test machining systems in the industry.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.452-457
• /
• 2003

As a fundamental study on developing elements with micro shape, micro mold parts machining and experiment of injection molding using it were performed. The ultra precision micro machining system with high functionality was fabricated, and utilized in the machining of micro parts. By using this machining system and micro end-mill tool, a micro circle column structure of high aspect ratio, diameter 60 $\mu\textrm{m}$, height 500 $\mu\textrm{m}$, was fabricated. And a micro lens molds were fabricated by using ball end-mill tool of 300 $\mu\textrm{m}$ diameter and diamond fly-cut tool of 150 $\mu\textrm{m}$ radius. A micro injection molding machine, which is clamping force 1.75 ton, injection capacity 2.8cc, was fabricated for injection molding experiment using micro molds. The injection molding experiment was performed by using the injection molding machine, micro cylinder structures and lens molds. This paper introduces these micro machining system and injection molding machine and demonstrates examples of injection molding using fabricated molds.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.197-200
• /
• 1997

In the metal cutting, machining accuracies had affected by tool deflection that had been generated by acting cutting force on the cutting edges. Generally, the CAD/CAM and a solid modeler had used for the simulation of cutting process only. Some NC codes for metal cutting have been generated by these simulation results. But, machining errors that had generated by the tool deflection has not solved using these system. In this study, determination algorithm for integration zone has been studied using the commercial solid modeler. The tool deflection error has calculated by the integration zone between the small chip and the cutting edges.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.9
• /
• pp.81-87
• /
• 2019

The automatic tool changer of a machining center consists of a tool magazine and a cam box, and the core components of the cam box are a roller gear cam and a turret. Recently, the roller gear cam of a cam box has been replaced by a ball gear cam. In this study, the design and machining method of ball gear cam for an automatic tool changer was studied. Additionally, an algorithm for a 4-axis post processing method was established from an instrumental formula by designing a ball gear cam, thus preventing machining at the bottom of ball end mill and enabling the ball on the turret to be driven at the entrance and exit of a curve without collision due to machining errors. In conclusion, machining using only the 4-axis method including the C-axis on a BC -Type 5-axis machine produced the desired ball gear cam.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.2
• /
• pp.95-102
• /
• 2002

Due to the development of the CNC machine tool and CAM software, sculptured surface machining can be broadly used in die and mold industries and ball end milling process is often used for the sculptured surface machining. It is found out how feedrate affects the precision of the machining and also tried to study the most suitable feedrate in specific cutting condition. Two eddy current sensors were used far measuring tool deflections of X, Y axis, dynamometer for cutting force and roundness tester for roundness. It was found that the tool deflection is getting better as tool path is going to further from the center of convex surface. The reason is that the cutting force is increased as the tool approaches to the center. Examining the roundness, cutting force and tool deflection characteristics, it was found that the most suitable feedrate is 90mm/min in convex surface and 120mm/min in concave surface.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.179-184
• /
• 1995

A new cutting parameter is defined in the spherical part of ball end-mill cutter. A series of slot cutting experiments were carried out to obtain the cutting parameter. The cutter contact area is expressed as the grid posiotion in the cutting plane using Z map. The cutting forces in each grid are calculated and saved as force map, prior to the average cutting forces calculation. The cutting force, in the arbitrary cutting area, can be easily calculated by summing up the cutting forces of the engaged grid in the force map. This model was verified in the inclined surface cutting by cutting test of a cylindrical part.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.12 s.189
• /
• pp.30-37
• /
• 2006

In this work, the surface integrity smoothened with a ball end mill was investigated. Because surface integrity mainly affects the manual finishing process, $RV_{AM}$(Remaining Volume After Machining) was introduced, and it gives the relation between machining process and finishing process. Runout and phase shift which adversely affect surface integrity were considered in the generation of surface topography. Cutting points in ball end milling were identified with positional vectors and a set of vectors which have the minimum height in unit area was selected for the generation of surface and $RV_{AM}$. $RV_{AM}$ variation according to runout and phase shift was calculated and experimentally verified in proposed HSM conditions for mold machining. From the simulations and the experiments, a desirable High Speed Machining condition was suggested.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.1113-1116
• /
• 2001

Recently, the needs of non-symmetric spherical lens are increasing. Machining non-symmetric spherical lens by general method is limited. This paper researches grinding machine method for non-symmetric spherical lens and accruable problems at processing lens using CAD/CAM. In addition, this paper researches the relation of curvatures to grinding wheel sizes.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.2
• /
• pp.44-49
• /
• 2017

In this study, the cutting conditions of moving speed, number of main axial revolutions, etc. are changed for the chrome molybdenum steel (SCM415) material and carbide ball end mill tool to study the changes for processing intensity in the cutting process. The results that confirm the intensity of the measured value of the specimen for SCM415 display the intensity with an average 1.0667 HrC. After the fact cutter, it was able to confirm the average intensity of 8.3815 HrC. In addition, the intensity value after image processing may determine the average intensity survey value of 5.8690 HrC and the different intensity values with image processing after face cutting are shown for an average of ${\pm}2.5125HrC$. The different value of intensity with the specimen and image processing is confirmed for an average of 4.8024 HrC. The results of comparing the intensity following the number of main axial revolutions and moving speed show that the intensity is highest for 3,000 rpm and F200, and lowest for 4,000 rpm and F200.