Evaluation and Improvement of Productivity in High-Speed NC Machining

1999 ◽  
Vol 122 (3) ◽  
pp. 556-561 ◽  
Author(s):  
X. Yan ◽  
K. Shirase ◽  
M. Hirao ◽  
T. Yasui
Keyword(s):  
High Speed ◽  
Nc Machining ◽  
Cutting Conditions ◽  
High Speed Machining ◽  
Machining Time ◽  
Time Constants ◽  
Nc Program ◽  
Kinematic Factor ◽  
Two Factors

The productivity of machining centers is influenced inherently by the quality of NC programs. To evaluate productivity, first an effective feedrate factor and a productivity evaluation factor are proposed. It has been found that in high-speed machining, these two factors depend on a kinematic factor which is a function of (1) command feedrate, (2) average per-block travel of the tool, (3) moving vectorial variation of the tool, and (4) ac/deceleration or time constants. Then an NC program simulator has been developed to evaluate productivity. With the simulator, the machining time can be calculated accurately and the cutting conditions can be extracted. Finally, three NC programs were implemented on high-speed machining centers and analyzed by the simulator. It was found that in mold and die machining, the productivity can be improved by increasing the acceleration and average travel and reducing the vectorial variation of the tool rather than the command feedrate. [S1087-1357(00)01303-4]

Study on High Speed Machining Strategies for Mold

2012 ◽  
Vol 591-593 ◽  
pp. 468-471
Author(s):  
Yong Xia Liu ◽  
Ru Shu Peng ◽  
Qiang Cheng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
High Speed ◽  
Intake Manifold ◽  
High Speed Machining ◽  
Machining Time ◽  
High Speed Milling ◽  
Tool Paths ◽  
Nc Program ◽  
Machining Strategies

The advantages and current problems for the application of high-speed machining technology in mold manufacturing are discussed. The requirements of mold high-speed machining for tool paths are summarized. Using the software of Cimatron E7.0，the NC program of the outer mold for a car engine’s V8 intake manifold is analyzed and optimized designed. Programming technology and optional of cutters have been introduced in detail. In the high speed milling stages, using the new cutters, the hardened mold can be machined to reach the required size, shape and surface roughness, and the machining time is reduced greatly. The method of making high speed NC template based on the software Cimatron E7.0. is introduced. Using this method, the maching efficiency is improved greatly, and the mold’ s surface quality better.

Optimization of TiAlN Coatings on HSS Inserts by Physical Vapour Deposition Process Using Taguchi Technique

2014 ◽  
Vol 879 ◽  
pp. 27-31
Author(s):  
Mohamed Fadzil Fazira ◽  
A.M. Samsiah ◽  
M.A. Selamat ◽  
M. Amin ◽  
R.J. Talib
Keyword(s):  
High Speed ◽  
Vapour Deposition ◽  
Deposition Process ◽  
High Speed Machining ◽  
Physical Vapour Deposition ◽  
Taguchi Technique ◽  
Machining Time ◽  
Modern Technologies

High-speed machining is one of the modern technologies that enable the increase in efficiency, accuracy and quality of workpieces, as compared to conventional cutting. At the same time, it decreases costs and machining time [.

A Fracture Mechanics Approach to the Prediction of Tool Wear in Dry High Speed Machining of Aluminum Cast Alloys: Part 2 — Model Calibration and Verification

Tribology ◽  
2005 ◽  
Author(s):  
Alexander Bardetsky ◽  
Helmi Attia ◽  
Mohamed Elbestawi
Keyword(s):  
Fracture Mechanics ◽  
Tool Wear ◽  
Model Calibration ◽  
High Speed ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
High Speed Machining ◽  
Wear Model ◽  
Wide Range ◽  
Cast Alloys

Experimental study has been carried out to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al-Si cast alloys that are commonly used in the automotive industry. The experimental setup and force measurement system are described. The test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in Part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. The prediction errors were found to be less then 7%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material.

The Hammer QSD-Quick Stop Device for High Speed Machining and Rubbing

1981 ◽  
Vol 103 (1) ◽  
pp. 13-21 ◽  
Author(s):  
J. T. Black ◽  
C. R. James
Keyword(s):  
Plastic Deformation ◽  
High Speed ◽  
Cutting Conditions ◽  
High Speed Machining ◽  
Machined Surface ◽  
Orthogonal Machining

A quick stop device (QSD) was designed for use in orthogonal machining and rubbing experiments. QSD’s are used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. These “frozen” specimens are helpful in examining the plastic deformation that occurs in the regions of compression and shear which form the chip; the secondary shear at the tool-chip interface; and the nose ploughing/flank rubbing action which operates on the newly machined surface. The Hammer QSD employs a shear pin mechanism, broken by a flying hammer, which is traveling at the same velocity as the workpiece. The device has been successfully tested up to 6000 sfpm (30.48 m/sec).

Development of Cutting Strategy in Ultra-Precision Raster Milling of Freeform Surface

2014 ◽  
Vol 633-634 ◽  
pp. 615-619
Author(s):  
Su Juan Wang ◽  
Su Et To ◽  
Xin Chen ◽  
Jian Qun Liu
Keyword(s):  
Cutting Parameters ◽  
Integrated System ◽  
Machining Process ◽  
Freeform Surface ◽  
Machining Time ◽  
Tool Paths ◽  
Nc Program ◽  
Ultra Precision ◽  
Cutting Strategy

This paper studies the development of cutting strategy in the fabrication of freeform surface in ultra-precision raster milling (UPRM). The tasks of developing cutting strategy in freeform machining involve in the selection of cutting parameters and the planning of tool paths. An integrated system is built in this study to develop the cutting strategy, automatically generate NC program, simulate the tool paths and machining process, as well as make predictions for the machining time and the surface quality of the raster milled freeform surface. Experiment is conducted to verify the developed system and the experimental results show that the system is applicable for the machining of freeform surface in UPRM. This study therefore contributes to avoiding the need to conduct expensive and time consuming trial cutting tests to ensure the product quality in the freeform machining.

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

Prevention of Material Deterioration in ECM of Sintered Carbide with Iron Ions

2017 ◽  
Vol 11 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Akihiro Goto ◽  
◽  
Atsushi Nakata ◽  
Sicong Wang ◽  
Nagao Saito ◽  
...  
Keyword(s):  
High Speed ◽  
Electrochemical Machining ◽  
High Speed Machining ◽  
Conductive Liquid ◽  
Sintered Carbide ◽  
High Speeds ◽  
Quality Degradation ◽  
Fe Ions ◽  
Electrical Source

This study focuses on electrochemical machining as a method of processing sintered carbide at high speeds. Previous studies have suggested the possibility of using electrochemical machining to achieve high-speed machining of sintered carbide. However, there has been strong resistance in industry against bringing sintered carbide into contact with a conductive liquid. This is because the material quality of sintered carbide is degraded by the elution of Co when it is brought into contact with a conductive liquid.In previous reports, the authors have shown that it is possible to control two modes of Co elution occurring during electrochemical machining: the elution from sintered carbide when it comes into contact with an electrolyte, and the selective elution of Co due to difference in the speeds of WC dissolution and elution of Co when sintered carbide is connected to an electrical source for processing. It was shown that it is possible to control the elution Co in sintered carbide when it comes into contact with an electrolyte by adding Co ions to the electrolyte to increase the concentration of Co ion, and that it is possible to prevent the excessive elution of Co by using a bipolar electrical source for machining. Although we showed that it is possible to carry out electrochemical machining of sintered carbide without degrading its quality, adding of large amounts of Co ions to the electrolyte entails a high cost. In this report, therefore, we describe the addition of Fe ions instead of Co ions to perform electrochemical machining of sintered carbide without quality degradation.

Generation of NC Program for Realizing High Speed Feed Rate of Cutting Tool

2012 ◽  
Vol 523-524 ◽  
pp. 398-403
Author(s):  
Shintaro Sakurai ◽  
Hideki Aoyama ◽  
Noriaki Sano
Keyword(s):  
Feed Rate ◽  
High Speed ◽  
Cutting Tools ◽  
Sampling Time ◽  
Machined Surface ◽  
Nc Program ◽  
Circular Arcs ◽  
Offset Curves ◽  
Acceleration And Deceleration

As the feed rate of cutting tools is influenced by the quality of NC programs, this causes two problems when cutting freeform surfaces using NC machine tools, one is the feed rate does not reach the specified value, and the other is the quality of the machined surface decreases due to the large acceleration and deceleration of the control axes. One reason for these problems is that the method to generate cutter location data does not take into consideration the sampling time of the NC controller. To improve these problems, the approximation of offset curves with a series of circular arcs has generally been proposed. But conventionally, circular arc interpolation algorithms are complicated and not rational. So, in this study, we proposed two simple NC program generation methods. (1) Approximate the offset form with circular arcs based on the location of the center of curvature. (2) Make the distance between the cutter location points of the NC data an integral multiple of the “feed rate command F × sampling time T”. We also confirm the effectiveness of the proposed methods by simulations and experiments.

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