• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.6
• /
• pp.739-745
• /
• 2010

The roller gear cam can control the rotational follower periodically by attaching several roller on the circumstance of follower shaft and it is widely used in non-backlash and precise actuating mechanism such as index table or ATC of machine tools. For machining the roller gear cam, 5 axis CNC machine tool is used and the geometric principle of CAM mechanism must be adopted to generate the NC-code and to develop the special CAD/CAM software because there is not commercial CAM system to machine the roller gear cam. The maker of the specially developed software in domestic user is generally from Japan or Taiwan. However these softwares do not reflect the post processing technique for finish machining in the module. Also, there is some limitation for further new application of itself and it needs higher costs for further application. In this study, the CAD/CAM software to overcome these problem was developed. And its reliability was verified by applying it in 5-axis CNC machining. Finally, the experimental result conducted in the 5-axis machining show good consistency in the movement of follower along the flute and in its Size.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.8
• /
• pp.2001-2011
• /
• 1993

This study deals with the machining of sculptured surfaces on 5-axis CNC milling machine with end mill cutter. The study (I) has the following contents. In 5-axis CNC milling, CL-data consist of CC-data and cutter axis direction vector at the CC-point. Thus, in machining of the sculptured surface on 5-axis CNC milling machine, determination of the direction vector of the milling cutter is very important. The direction vector is obtained by the fact that bottom plane of the milling cutter must not interfere with the free-form surface being machined. The interference is checked by the z-map method which can be applied in all geometric types of the sculptured surfaces. After generating NC part programs from 5-axis post-processing algorithms, sculptured surfaces were machined with 5-axis CNC milling machine (CINCINNATI MILACRON, 20V-80). From these machining tests, it was shown that the machining of the free-form surfaces on 5-axis CNC milling machine with the end mill has smaller cusp heights and shorter cutting time than on 3-axis CNC milling machine with the ball-end mill. Thus, 5-axis CNC end milling was effective machining method for sculptured surfaces. The study (II) deals with the prediction of cusp height and the determination of tool path interval for the 5-axis machining of sculptured surfaces on the basis of study(I).

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.8
• /
• pp.2012-2022
• /
• 1993

For the machining of the sculptured surfaces on 5-axis CNC milling machine, the milling cutter direction vector was determined in the study (I) with 5-axis post-processing. Thus, it was possible to cut the sculptured surfaces on five-axis CNC milling machine with the end mill cutter. Then, for smooth machined surfaces in five-axis machining of free-from surfaces, this study develops an algorithm for prediction of cusp heights. Also, it generates tool path such that the cusp heights are constrained to a constant value or under a certain value. For prediction of the cusp height between two basis points, a common plane, containing the line crossing two basis points and the summation vector of two normal vectors at two basis points, is defined. The cusp height is the maximum value of scallops on the common plane after end mill cutter passes through the common plane. Sculptured surfaces were machined with CINCINNATI MILACRON 5-axis machining center, model 20V-80, using end mill cutter. Cusp heights were verified by 3-dimensional measuring machine with laser scanner, WEGU Messtechnik GmbH.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.6
• /
• pp.1-9
• /
• 2002

This study describes the geometric characteristics and the 5-axis machining method in order to make end mill cutter coming with insert tips. End mill geometry is consisted of flute part and insert tip part. Flute part modeled by using ruled surfaces with constant helix angle, and insert tip part modeled by rectangular planes containing tapped hole of specified direction in its center. In this study, the modeled insert tip part considered both of a radial rake angle and a axial rake angle, because they were important cutting conditions. In order to machining the virtual end mill defined from geometric characteristics, we programmed a special software to machining the end mill considered in this study. This software can generate NC-codes about following processes, end milling or ball end milling of flute part end milling of rectangular plane, centering of hole, drilling of hole, and tapping of hole. Ant sampled end mills were modeled and machined on 5-axis CNC machining center with two index tables. Since machined end mills were very agreeable to designed end mills, we saw that the method proposed in this study can be very useful for manufacturing of end mill body with insert tip.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.4
• /
• pp.36-43
• /
• 2007

Dieless CNC forming is an innovative technology which can form various materials with complex shape by numerically controlled incremental forming process. In order to apply the technology to industrial parts, however, many problems such as spring-back, rising of material, and trimming difficulty must be solved. In this paper a new dieless CNC forming method to improve forming quality is proposed, which consists of how to modify its original shape in CAD and how to generate its CNC tool path in CAM. The effectiveness of the proposed procedures is tested with a brake dust shield of a vehicle. The results shows that the method proposed enhances the forming quality up to 48% compared to traditional method.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.5
• /
• pp.83-89
• /
• 2010

In this paper, the dynamic response of a CNC 5 Axles machining center was analyzed and then controlled passively by using the dynamic absorber. For the simplification of the theoretical approach, the CNC 5 Axles machining center was modeled as a flexible beam(Bed) having a point mass(Column), two discrete systems(a Table-set and a dynamic absorber). Specifically by using the dynamic absorber, the dynamic response of a Table-set which be caused by the vibration of a flexible beam, was reduced down to the infinitesimal level. The optimal design factors of the dynamic absorber were obtained from the minimization of the cost function. It was found that the natural frequencies of a UT-380 machining center be varied due to the movement of the Table-set. In view of the dynamic response of a Table-set, the larger spring stiffness and mass of the dynamic absorber were found to give the greater reduction.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.225-226
• /
• 2007

• Journal of Korean Institute of Industrial Engineers
• /
• v.21 no.2
• /
• pp.217-237
• /
• 1995

One of the most distinguished advantages of five-axis machining is that complex free surfaces(such as impeller) can be machined by one setup. Five-axis CNC machine, however, is very expensive so that its usage is restricted to a few large companies. As an economical approach to five-axis machining, this paper presents a method for machining the five-axis free surfaces(using ball-end mill) on a three-axis CNC machine with an index table. The method developed consists of: a) determining the minimum number of part setups and their interference-free and collision-free potential machining area, b) calculating actual machining area for each setup, and c) generating 3-axis cutter path for each part setup. The method has been successfully tested via computer simulations for several complex surfaces including impeller.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.7 no.5
• /
• pp.1-7
• /
• 1997

In this paper, a neuro-contouring control scheme for the high precision machining of CNC machine tools is descrihed. The proposed control system consists of a conventional controller for each axis and an additional neuro-controller. For contouring control, the contour error must be computed during realtime motion, but generally the contour error for nonlinear contours is difficult to he directly computed. We, therefore, propose a new contour error model to approximate real error more exactly, and here we also introduce a cost function for better contouring performance and derive a learning law to adjust the weights of the neuro-controller. The derived learning law guarantees good contouring performance. Usefulness of the proposed control scheme is demonstrated hy computer simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.245-246
• /
• 2006

For developing 5-axis laser cutting systems, many problems such as rotating of laser head or table, 5-axis tool path generation and collision avoidance between laser head and product should be solved. In this paper, a five-axis laser cutting machine with table swivel and rotary type configuration is developed. The five axes (X,Y,Z,A,B) are controlled and interfaced to PC via MMC board. Two kinds of CAM S/W such as commercial 5-axis CAM S/W(Euclid) and UG-API are engaged to generate NC code for the developed 5-axis laser cutting machine.