Papers by Keyword: Drilling

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Authors: Rui Jian, Jun Zhao
Abstract: This paper is concerned with the problem of license plate recognition of vehicles. A recognition algorithm based on dynamic sliding window to binarize license plate characters is proposed. While a connected domain approach is presented to cope with the degradation characters. There are three steps to recognize the characters. First, the characters are classified by their features. Then, based on such classification a grid method is used to construct the feature vector. Finally, least square support vector machine is employed to recognize these characters. The test results show the high recognition rate and also illustrate the effectiveness of the proposed algorithm.
Authors: Hui Cheng, Yuan Li, Kai Fu Zhang, Jun Zhang
Abstract: Thrust force is the most important element which will cause delamination in the drilling of CFRP. This paper developed a dynamic thrust force prediction model for CFRP drilling, by firstly, representing the drilling process into a three-step model. Secondly, the dynamic thrust force is decomposed into two parts. Thirdly, the thrust force components on both tool major cutting edge and chisel edge is developed according to the analysis on infinitesimal cutting unit. Lastly, several experiments are performed to compare the result of thrust force analyzed, which proves that the purposed model can analyze the dynamic thrust force in drilling of CFRP well.
Authors: Cheng Long Zhang, Ping Fa Feng, Zhi Jun Wu, Ding Wen Yu
Abstract: Rotary ultrasonic machining is a hybrid machining process that combines diamond grinding and ultrasonic machining. The mathematical predictive material removal rate models have been developed in rotary ultrasonic machining with a constant pressure. However, there is no report on mathematical predictive cutting force model in rotary ultrasonic drilling at a constant feedrate presently. Since cutting force can not only reflect the processing state, but also affect the machined surface quality, it is necessary to develop a mathematical model for predicting cutting force which can forecast the machining results. This paper presents a mathematical model to predict the cutting force in rotary ultrasonic machining. On the basis of this model, the relations between cutting force and controllable machining parameters are researched by numerical computation method. This paper also researches the influences of spindle speed and feedrate on cutting force by experiments. The results observed through the experiments agree well with the relations generated from the mathematical model, which verify the developed model.
Authors: Qin He Zhang, Jian Hua Zhang, J.H. Cheng, C.Q. Zhang, Sheng Feng Ren
Authors: L.J. Zheng, Cheng Yong Wang, Yue Xian Song, L.P. Yang, Y.P. Qu, Ping Ma, L.Y. Fu
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.
Authors: Kun Xian Qiu, Sheng Qin, Chun Xin Ge, Ming Chen
Abstract: Both aluminum alloy and titanium alloy have been widely used in aerospace, aviation, military and automotive industries. This research presents a study of modified drills for drilling aluminum alloy and titanium alloy. The modified drills can be expected to reduce the cutting forces and torque. A set of experiment was carried on to investigate the performance of the modified drills. A method to quantitative assess of the reduction of the thrust force and torque was given below, and the calculation shows that the modified drills can reduce the thrust force and the torque by as high as 21.16% and 90.48%, respectively, as compared to the conventional drills under the same conditions.
Authors: R. Ganesh, R. Satyaprakash, M. Prakash, Chandrasekaran Kesavan
Abstract: This paper aims to understand the influence of sintering temperature on the drilling performance of Al 2219 – SiCp composite. This type of composite is currently used in aerospace and transportation industries. Drilling is the most frequently employed operation of secondary machining owing to the need for fabrication. This composite is usually subjected to precipitation heat treatment and needs the study of influence of sintering temperature on machining performance. The composite is fabricated through powder metallurgy route. The drilling tests are conducted with PCD drill of 5 mm diameter and 118° point angle. The experiments are conducted under conditions of different spindle speeds of 500, 1000 and 1500 rpm and feed rates of 10, 15 and 20 mm/min. Specific cutting pressure and surface roughness of the hole are considered as performance indicators during the study. Weight fraction of the reinforcement and sintering temperature are found to have significant influence on the drilling performance of the composites.
Authors: Tadeusz Mikolajczyk, Adrian Olaru, Piotr Krainski
Abstract: The paper shows an adaptive system for drilling. To drill diameter measure video optical method with USB camera was used. Rotation of drill tool was controlled using an inverter. Adaptive system was controlled by PC using special software made in C++.
Authors: Marek Vrabel', Ildikó Maňková, Jozef Beňo, Ladislav Kandráč, Jozef Stahovec
Abstract: Article deals with design of adaptive control system for drilling process of aerospace critical components. The system proposed in this paper is directed towards real the time control of surface roughness parameter Ra. Proposed model for monitoring and control consists of surface roughness prediction system and decision making subsystem. The artificial neural network was employed to calculate surface roughness parameter Ra through of process monitoring indices such as torque Mz, force Fz, power P and cutting conditions feed f, cutting speed vc. Test samples were nickel based super alloy Udimet 720 used as a basic constructional material of discs for gas turbine engines.
Authors: Eugen Pămîntaş, Gheorghe Cristian Turc, Felicia Veronica Banciu
Abstract: so-called llightweights materials (aluminum, magnesium, titanium) and their alloys due to multiple applications in various leading industries (aeronautics, automotive, electrical) always stayed in researchers attention both in order to improve their mechanical characteristics and to optimize technologies for cutting processing them. This paper is part of these concerns by trying to find answers to some questions about high-speed drilling of electrolytic aluminum parts and has as targets of the investigation the following: the material machinability, the working parameters optimization, the tool used in drilling and the quality obtained after machining.
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