• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.81-87
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• 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 Recently, the roller gear cam of a cam box has been replaced by a ball gear cam.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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.98-104
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• 2020

In this work, a study on the 5-axis machining of ball gear cam is conducted which is a continuation of reference [1]. The ball gear cam used in this study delivers motion in conjunction with the ball supported by the turret. Therefore, it requires carbonizing heat treatment and is usually completed using a 4-axis machining with a carbide ball end mill. If the nose part of the ball end mill is not allowed to participate in the machining, then CBN tools without the nose part can be used. However, machining of certain shapes can be carried out only by contacting the ball in some of the areas on either side which can improve the surface of the machining. This requires a 5-axis machining in order to maintain a constant angle for the processing path. Therefore, in this work, the 5-axis machining method is studied in order to maintain the direction of the cutter axis at a constant angle with the tangent direction of the curve-ball gear cam. Furthermore, the 5-axis machining program for the ball gear cam was developed and the machining experiment was completed and verified.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.19-26
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• 1997

The manufacture of an impeller typically requires the 5-axis CNC machining, since the impeller is usually under working conditions such as high speed, high temperature, and high pressure. Thus, this study contributes to development of an exclusive CAM system for effective 5-axis CNC machining of a ruled surface type impeller. In this study, the sampled impeller is made of blades and a body and the blade consists of ruled surfaces between hub curve and shroud curve. In the post processing for 5-axis NC part program, the cutter axis direction vector is the straighten vector on ruled surface. The position of ball center in ball end mill cutter is decided on the interference check between the cutter and body surface of impeller using with the modified z-map method that z-axis is the same of cutter axis direction vector. The exclusive CAM system for an impeller developed in this study was very effective for designs and 50-axis machining of a ruled surface type impeller.

• Korean Journal of Computational Design and Engineering
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• v.7 no.4
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• pp.254-261
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• 2002

Small marine propeller is generally machined by 5-axis machining. This paper suggests a method to create geometric model from point array data and 4-axis machining NC data for propeller. With conventional method, the setting posture should be changed, because propeller has front and back surface of wing. The change of setting posture has a bad influence on precision of propeller. So this paper pro-poses a method to machine propeller by single setup for 4-axis machining. The cutter moves to parallel direction of the XY plane. To determine the cutter orientation efficiently, the' tilting guiding line' is proposed. A proposed algorithm is written in C language and successfully applied to the 5-axis milling machine of industrial field.

• Korean Journal of Computational Design and Engineering
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• v.4 no.2
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• pp.110-120
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• 1999

In general, turbine blades are usually machined on 5-axis NC machine. The 5-axis machining of sculptured surface offers many advantages over 3-axis machining including the faster material-removal rates and an improved surface finish. But it is difficult and time-consuming to generated interference-free 5-axis tool path. This paper describes research on the algorithm for generation of an interference-free 5-axis NC data for machining turbine blades. The approach, using the section profile derived from the intersection of cutting planes with a triangulated-surface approximation, includes (1) CL-data generation by detecting an interference-free heel angle (2) the calculation method for finding a adaptive feed-rate value, and (3) the inverse kinematics depending on the structure of 5-axis machine.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.94-102
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• 2019

Mono pump rotors are widely used in wastewater treatment plants, medicine, cosmetics, paint, paper, and chemical manufacturing, dairy production, public works, agriculture, and so on. A mono pump comprises two main parts: the rotor and stator. Typically, the rotor is machined using an expensive whirling machine. In this study, we developed an algorithm for 4-axis machining of the rotor on machining center (MCT). NC-code was obtained by applying the algorithm and finally the rotor of the mono pump was machined on a 4-axis MCT. Results of four sample experimental works showed close agreement with design geometries.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.69-77
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• 2001

This paper describes a method of calculating the feedrate for the constant cutting speed at a CL-point in 5-axis machining. Unlike 3-axis machining, 5-axis machining has the flexibility of the tool motions due to two rotation axes. But the feedrate at joint space differs from the feedrate at a tool tip(the CL-point) of the 3D Euclidean space for the tool motions. The proposed algorithm adjusts the feedrate based on 5-axis NC data, the kinematics of a machine, and the tool length. The following calculations is processed for each NC block to generate the new feedrate; 1) calculating the moving distance at the CL-point, 2) calculating the moving time by the given feedrate, 3) calculating the feedrate of each axis, 4) getting the new feedrate. The proposed algorithm was applied to a 5-axis machine which had a tilting spindle and a rotary table. Totally, the result of the algorithm reduced the machining time and smoothed the cutting-load by the constant cutting speed at the CL-point.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.393-402
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• 2000

Recently 5-axis NC machines are widely used in Korea. Since 5-axis machines have two more degrees of freedom than 3-axis machines, it is very important to find desirable tool positions(locations and orientations) in order to make an efficient use of expensive 5-axis NC machines. In this research an algorithm to determine “optimal” tool positions for 5-axis machining of sculptured surfaces is developed. For given CC(Cutter Contact) points, this algorithm determines the cutter axis vectors which minimize cusp heights and satisfy constraints. To solve the optimal problem, we deal with following major issues: (1) an approximation method of a cusp height as a measure of optimality (2) Identifying some properties of the optimal problem (3) a search method for the optimal points using the properties. By using a polyhedral model as a machining surface, this algorithm applies to sculptured surfaces covering: overhanged surface.

• Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.197-205
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• 2015

Bladed disk (BLISK) is a vital part in jet engines with a complicated shape which is exclusively machined on a five-axis machine and requires high accuracy of machining. Poor quality of tool orientation (e.g., false tool positioning and unsmooth tool orientation transition) during the five-axis machining may cause collision and machine vibration, which will debase the machining quality and in the worst case sabotage the BLISK. This paper presents a reference plane based algorithm to generate a set of smoothly aligned tool orientations along a tool path. The proposed method guarantees that no collision would occur anywhere along the tool path, and the overall smoothness is globally optimized. A preliminary simulation verification of the proposed algorithm is conducted on a BLISK model and the tool orientation generated is found to be stable, smooth, and well-formed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.3-4
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• 2007