Abstract: A developed method to predict the cutting forces in end milling of generalized corners is proposed in this paper. The cornering milling process is divided into a series of cutting segments with different cutting states. The mathematical model of the geometric relationship between cutter and the corner profile is established for each segment. Cutting forces is predicted by introducing the classical cutting force model. The computational results of cutting forces are in good agreement with experimental data.
Abstract: In this paper, some experiments were conducted to investigate tool wear when end-milling Inconel 718 with the TiAlN-TiN PVD coated carbide inserts. The worn tools were examined thoroughly under scanning electron microscope (SEM) with Energy Dispersive X-ray Spectroscopy and 3D digital microscope to expatiate tool wear morphologies and relevant mechanisms. The flank wear was uniformity in finishing milling process, and the average flank wear were selected as the criterion to study the effects of cutting parameters (cutting speed, feed per tooth, radial depth of cut, and axial depth of cut) on tool wear. Finally, the optimal combination of the cutting parameters for the desired tool life is obtained.
Abstract: In this paper, tool life, tool wear criteria, initial wear and cutting length at initial wear are picked out from 295 milling tool wear curves to calculate initial wear rate K0, final wear rate K1 and the ratio K between the two. By statistic analysis of K0, K1 and K, a statistical regularity between K0 and K1 is found, which indicates that the faster the initial wear, the shorter the tool life would be. Based on the statistical regularity, a milling tool rapid selection method is proposed, and an experiment on selecting the best tools for machining TC4 is carried out to verify the method. The results show that the method can reduce the consumption of material and time significantly, which confirm the efficiency of the method.
Abstract: A new grinding method for PCB drill-helical-conical grinding method which is combined helical method and conical method is introduced in this paper. Compared with conical grinding method, helical-conical grinding method avoids the tail rising problem and improves the clearance angle distribution along with the main cutting edge. The mathematical model of this method is given in this paper.
Abstract: Supported holes of Printed circuit board (PCB) are drilled with two different drill bits. Drilling force (thrust force and torque) and chip morphology are examined at different cutting parameters, and the effects of the two drills are discussed. The results indicate that the drilling force and chip morphology are affected by the feed rate, spindle speed and drill shape. Thrust force increases with the increasing feed rate, and decreases with the increasing spindle speed. Optimization of drill geometry can reduce the thrust force significantly, and is effective in chip breaking which can improve the chip evacuation during the drilling process.
Abstract: A printed circuit board or PCB consists of conducting layers typically made of thin copper foil and insulating layers laminated together. Holes through a PCB are typically drilled with tiny drill bits made of solid tungsten carbide. This paper focuses on cutting forces of drilling PCB. The influences of cutting speeds, feed rate and drill diameter on thrust force are investigated. Finally the drilling force experimental formula’s mathematical model is derived.
Abstract: Drilling is a particularly complicated machining process, and it becomes much more complicated when the workpiece is printed circuit boards (PCBs). PCB is composite materials with anisotropy. Even a small defect in PCB may cause great losses. Both the drilling process and PCB structure design have been researched by many scholars. But the investigations into the drilling processes of PCB are not systematic. The present review article address the report about tool materials and geometrics, cutting force, cutting temperature, radial run-out and damages occurring in drilling processes. And as a conclusion, some of these critical issues are proposed to meet the challenges in analysis and optimization for PCB drilling.
Abstract: Both the heavy cutting process and the importance of the chip control are discussed. Through analyzing the characteristics of the rough machining of the hydrogenated cylindrical shell, both the structure and the material of the turning tool for rough machining are designed. To test and verify the feasibility study on them, the contrast experiment between the new-type turning tool and the reference substance in cutting the 2.25Cr-1Mo-0.25V steel which is the material of hydrogenated cylindrical shell is made, then the service life and the chip-breaking performance of the tool are compared. Finally, the technical reference to design the new-type turning tools is summarized.
Abstract: On the basis of finite element analysis, the static transmitted torque of Hydraulic Expansion Toolholder is validated. At the same time fluid analysis software is used to investigate the oil pressure changes in oil chamber wall because of different rotation speed. Then through the fluid-solid coupling, the article analyzes the chuck clamping performance on the factors of expansion chuck and tool clearance, rotation speed, and hydraulic oil pressure when toolholder on the state of high rotation speed.
Abstract: The virtual prototype is a computer simulation model of the physical product that can be analyzed like a real machine. This paper studies the helical milling unit based on the virtual machine tool. The helical milling unit is first designed according to the kinematics of the helical milling. The main parts of the equipment include rotating mechanism, orbital agency and radial offset organization. Based on the feasibility analysis of the structure, the three-dimensional geometrical model is built in the Solidworks software. The key parts in the model are separated from the device and introduced into the finite element analysis (FEA) software, according to the cutting loads tested from experiment, static and dynamic modal analysis and harmonic response analysis are carried out for the key parts of this device. The results show that the static and dynamic stiffness can meet design requirement.