Tool Posture Planning Method for Low Rigidity Workpiece Considering Elastic Deformation Caused by Cutting Force

2020 ◽  
Author(s):  
Jun'ichi Kaneko ◽  
Yuki Okuma ◽  
Shumpei Sugita ◽  
Takeyuki Abe
Keyword(s):  
Cutting Force ◽  
Elastic Deformation ◽  
Feed Rate ◽  
Machining Process ◽  
Machining Time ◽  
Machined Surface ◽  
Nc Program ◽  
Blade Shape ◽  
Tool Posture ◽  
The Moment

Abstract In machining process for a workpiece with low rigidity such as a blade shape, it is required to consider elastic deformation of the workpiece shape itself due to cutting force. Conventionally, reduction of the cutting force in machining process is achieved by optimization of feed rate value in NC program. On the other hand, since a decrease in the feed rate causes an increase in machining time. So, other optimization algorithm is required. In this paper, a new method to suppress the elastic deformation of the workpiece by changing tool posture in multi-axis controlled machining is proposed. The proposed method is intended for finish machining process for blade shape with a ball end mill. In the proposed method, first, the cutting force loaded on the workpiece surface in a certain posture candidate is predicted, and an instantaneous cutting force at the moment when the machining surface is generated is estimated by model-based computer simulation. Based on this results, the amount of elastic deformation on the machined surface is estimated by FEM. This process is repeated at each cutter location and tool posture candidate, and the new tool posture that can minimize machining error caused by the elastic deformation is determined at each cutter location.

Optimization Method of Rotational Axis Motion in 5-Axis Controlled Machining to Keep Command Tool Feed Rate

2020 ◽  
Author(s):  
Takayuki Nakamura ◽  
Kohei Ichikawa ◽  
Masanobu Hasegawa ◽  
Jun'ichi Kaneko ◽  
Takeyuki Abe
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Machining Process ◽  
Rotational Axis ◽  
Feed Speed ◽  
Machining Processes ◽  
Machining Time ◽  
Machined Surface ◽  
Lead Angle ◽  
Tool Posture

Abstract In recent machining processes, 5-axis controlled machine tool is widely used for machining complicated workpiece shape with curved surface. In such process, to achieve high productivity, planning method of cutting conditions to satisfy both following the commanded tool feed rate in machining process and realization of good surface roughness are required. In conventional study, it is known that lead angle of tool posture against local machined surface influence the surface roughness. Then, common commercial CAM systems have already functioned to avoid interference and control the lead angle in each cutter location. However, in the generated cutter locations by the conventional algorithms, when the tool posture changes rapidly, there is a problem that actual feed rate does not reach the command value and machining time becomes longer than expected. In this paper, we propose the new tool posture correction algorithm. In the proposed method, first, the rotational axis that causes the feed speed rate decline is specified by preliminary experiments. And, the jerk value that is the threshold for the feed speed decline is investigated. After that, for the NC program, the command value of the target axis is modified within a range where interference of cutting tool does not occur, thereby preventing a decline in the actual feed rate. This paper describes an outline of the proposed modification method and the effect of the modification of the target axis positions on the lead angle and the actual feed rate.

scholarly journals Development of smart machining system for optimizing feedrates to minimize machining time

2017 ◽  
Vol 5 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Hong-seok Park ◽  
Bowen Qi ◽  
Duck-Viet Dang ◽  
Dae Yu Park
Keyword(s):  
Cutting Force ◽  
Machining Process ◽  
Cnc Machine ◽  
Machining Time ◽  
Virtual Machining ◽  
Milling Operations ◽  
Nc Program ◽  
Machining System ◽  
Optimal Feed ◽  
Smart Machining

Abstract Feedrate optimization is an important aspect of getting shorter machining time and increase the potential of efficient machining. This paper presents an autonomous machining system and optimization strategies to predict and improve the performance of milling operations. The machining process was simulated and analyzed in virtual machining framework to extract cutter-workpiece engagement conditions. Cutting force along the cutting segmentation is evaluated based on the laws of mechanics of milling. In simulation, constraint-based optimization scheme was used to maximize the cutting force by calculating acceptable feedrate levels as the optimizing strategy. The intelligent algorithm was integrated into autonomous machining system to modify NC program to accommodate these new feedrates values. The experiment using optimized NC file which generates by our smart machining system were conducted. The result showed autonomous machining system, was effectively reduced 26%. Highlights The smart machining system was implemented in the CNC machine. Optimal feed rates enhance machine tool efficiency. The smart machining system is reliable to reduce machine time.

Off-Line Feedrate Optimization Based on Simulation of Cutting Forces

2009 ◽  
Vol 407-408 ◽  
pp. 408-411
Author(s):  
Chen Zhang
Keyword(s):  
Cutting Force ◽  
Optimization Algorithm ◽  
Cutting Forces ◽  
Machining Process ◽  
Machining Time ◽  
Set Constraints ◽  
Machining Quality ◽  
Feedrate Optimization ◽  
Nc Program ◽  
Selection Of

The strategies of selection of feedrate are studied in the ball-end machining process. The optimization algorithm utilizes the objective requirements of a line of NC program to set constraints relation between cutting force and feedrate and optimizes feedrate by controlling the variety ranges of the instantaneous cutting force specified in the cutting forces simulation. Off-line feedrate optimization software for complex sculptured is developed. For a line of NC program, the developed software calculates instantaneous cutting force and an optimization algorithm is used to acquire desired feedrate. The machining experimental results show that the proposed algorithms are satisfying in reduction of machining time and improvement of machining quality.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

scholarly journals The Comparative Study on Cutting Performance of Different-Structure Milling Cutters in Machining CFRP

2018 ◽  
Vol 8 (8) ◽  
pp. 1353
Author(s):  
Tao Chen ◽  
Fei Gao ◽  
Suyan Li ◽  
Xianli Liu
Keyword(s):  
Carbon Fiber ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Edge ◽  
Cutting Performance ◽  
Machining Process ◽  
Carbon Fiber Composites ◽  
Machined Surface ◽  
Milling Cutter ◽  
Machined Surface Quality

Carbon fiber reinforced plastic (CFRP) is typically hard to process, because it is easy for it to generate processing damage such as burrs, tears, delamination, and so on in the machining process. Consequently, this restricts its wide spread application. This paper conducted a comparative experiment on the cutting performance of the two different-structure milling cutters, with a helical staggered edge and a rhombic edge, in milling carbon fiber composites; analyzed the wear morphologies of the two cutting tools; and thus acquired the effect of the tool structure on the machined surface quality and cutting force. The results indicated that in the whole cutting, the rhombic milling cutter with a segmented cutting edge showed better wear resistance and a more stable machined surface quality. It was not until a large area of coating shedding occurred, along with chip clogging, that the surface quality decreased significantly. At the stage of coating wear, the helical staggered milling cutter with an alternately arranged continuous cutting edge showed better machined surface quality, but when the coating fell off, its machined surface quality began to reveal damage such as groove, tear, and fiber pullout. Meanwhile, burrs occurred at the edge and the cutting force obviously increased. By contrast, for the rhombic milling cutter, both the surface roughness and cutting force increased relatively slowly.

Contrast Research on Cutting Forces in 4-Axis and 5-Axis Blade Machining Process

2010 ◽  
Vol 142 ◽  
pp. 209-213
Author(s):  
Tong Wu ◽  
Can Zhao ◽  
Guang Bin Bu ◽  
Dun Wen Zuo
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Test Method ◽  
Machining Process ◽  
Paper Test ◽  
Nc Program ◽  
Blade Machining ◽  
The Difference

In this paper, test method was used to study the distribution of cutting force while blade machined with 4-axis and 5-axis NC program. The main difference between the two program was given. The difference of machining forms between 4-axis and 5-axis has led to their cutting forces distribution were different. The change of cutting force in 4-axis machining was large while the 5-axis machining was relatively stable. 5-axis cutting force had no impact comparing with 4-axis, which is more suitable for blade machining.

Study on the cutting performance in machining assembled hardened steel workpiece with torus cutter

2019 ◽  
Vol 234 (4) ◽  
pp. 701-709
Author(s):  
Tao Chen ◽  
Weijie Gao ◽  
Guangyue Wang ◽  
Xianli Liu
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Surface Quality ◽  
Wear Mechanism ◽  
Hardened Steel ◽  
Cutting Performance ◽  
Machining Process ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Two Sides

Torus cutters are increasingly used in machining high-hardness materials because of high processing efficiency. However, due to the large hardness variation in assembled hardened steel workpiece, the tool wear occurs easily in machining process. This severely affects the machined surface quality. Here, we conduct a research on the tool wear and the machined surface quality in milling assembled hardened steel mold with a torus cutter. The experimental results show the abrasive wear mechanism dominates the initial tool wear stage of the torus cutter. As the tool wear intensifies, the adhesive wear gradually occurs due to the effect of alternating stress and impact load. Thus, the mixing effect of the abrasive and adhesive wears further accelerates tool wear, resulting in occurrence of obvious crater wear band on the rake face and coating tearing area on the flank face. Finally, the cutter is damaged by the fatigue wear mechanism, reducing seriously the cutting performance. With increase of flank wear, moreover, there are increasingly obvious differences in both the surface morphology and the cutting force at the two sides of the joint seam of the assembled hardened steel parts, including larger height difference at the two sides of the joint seam and sudden change of cutting force, as a result, leading to decreasing cutting stability and deteriorating seriously machined surface quality.

Generation of High Aspect Ratio Micro Holes by a Hybrid Micromachining Process

2007 ◽  
Author(s):  
Murali M. Sundaram ◽  
Sridevi Billa ◽  
Kamlakar P. Rajurkar
Keyword(s):  
Aspect Ratio ◽  
Ultrasonic Vibration ◽  
Machining Process ◽  
Hole Drilling ◽  
Micro Edm ◽  
Shape Distortion ◽  
Machining Time ◽  
Machined Surface ◽  
Electro Discharge Machining ◽  
Debris Removal

Drilling a micro hole with an aspect ratio above 10 is a challenging task for any-micromachining process. In micro electro discharge machining (micro EDM), a proven metallic micromachining process, this is due to the problems associated with debris removal. In such cases, where the capabilities of existing macro machining methods are constantly being challenged, innovative micro manufacturing approaches are required to make progress. Hybrid micromachining is one such approach in which the synergy of constituent processes is exploited to achieve desired results. In this paper, the results of ultrasonic vibration assisted micro electro discharge machining process are presented. This hybrid process is capable of deep hole drilling with aspect ratio of 20 in austenitic stainless steel by overcoming the limitations in the debris removal faced in the typical micro EDM process. Other benefits of ultrasonic vibration are the savings in machining time, and less tool wear. It is also noticed that the ultrasonic vibration causes some shape distortion and produces rougher machined surface.

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.

scholarly journals Pulsed Magnetic Field Treatment of TiAlSiN Coated Milling Tools For Improved Cutting Performances

2021 ◽  
Author(s):  
Hao Qu ◽  
Lin Zhang ◽  
Zhe Chen ◽  
Lei Zhang ◽  
Kyle Jiang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Cutting Force ◽  
Processing Parameters ◽  
Cutting Performance ◽  
Machining Process ◽  
Pulsed Magnetic Field ◽  
Machined Surface ◽  
Wear Area ◽  
Cutting Vibration

Abstract In this study a pulsed magnetic treatment was attempted to improve the cutting performance of the TiAlSiN coated WC-12wt%Co cemented carbide end mills and the effects of the strength of the pulsed magnetic field on the cutting forces, the cutting vibrations, the tool wear, the machined surface roughness and mechanical properties were investigated. It is found that the cutting performances of the coated tools are successfully improved with a relatively lower cutting force and less wear area. The average resultant cutting force Fxyave decrease by 14.53% in the last machining process when the optimum processing parameters of 0.5T magnetic field is used, accompanying a maximum decrease of 46.8% in the cutting vibration. The maximum reductions of 57.65% and 25.4% in the flank wear and the average surface roughness of the workpiece are obtained respectively after the treatment. Both the hardness and toughness of the cemented carbides are slightly improved with the imposition of the field. The improvements in the cutting performance of the tool are attributed to the enhanced adhesion strength between the coating and matrix, which is caused by the increased compressive residual stress induced by the PMT.

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