Study Performance of Cylindrical Grinding On Straightness

Transcription

1 UNIVERSITI TEKNIKAL MALAYSIA MELAKA Study Performance of Cylindrical Grinding On Straightness Thesis submitted in accordance with the partial requirement of the Universiti Teknikal Malaysia Melaka for the Degree of Bachelor of Manufacturing Engineering (Manufacturing Process) with Honours BY MOHD AFFENDY BIN SAMDIN Faculty of Manufacturing Engineering May 2008

2 UTeM Library (Pind.1/2007) UNIVERSITI TEKNIKAL MALAYSIA MELAKA BORANG PENGESAHAN STATUS LAPORAN PSM JUDUL: STUDY PERFORMANCE OF CYLINDRICAL GRINDING ON STRAIGHTNESS SESI PENGAJIAN: SEMESTER 1 & /2008 Saya MOHD AFFENDY BIN SAMDIN mengaku membenarkan laporan PSM / tesis (Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut: 1. Laporan PSM / tesis adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan untuk tujuan pengajian sahaja dengan izin penulis. 3. Perpustakaan dibenarkan membuat salinan laporan PSM / tesis ini sebagai bahan pertukaran antara institusi pengajian tinggi. 4. *Sila tandakan ( ) SULIT TERHAD (Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia yang termaktub di dalam AKTA RAHSIA RASMI 1972) (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan) TIDAK TERHAD (TANDATANGAN PENULIS) Alamat Tetap: NO. 34, KG. KEPALA BENDANG, KEPALA BATAS, ALOR STAR, KEDAH. (TANDATANGAN PENYELIA) Cop Rasmi: Tarikh: Tarikh: * Jika laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.

3 DECLARATION I hereby declare that this report entitled STUDY PERFORMANCE OF CYLINDRICAL GRINDING ON STRAIGHTNESS is the result of my own research except as cited in the references. Signature : Author s Name : MOHD AFFENDY BIN SAMDIN Date : iii

4 APPROVAL This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Manufacturing Process) with Honours. The members of the supervisory committee are as follow: MOHD AMRI BIN SULAIMAN Main Supervisor (Official Stamp & Date) iv

5 ABSTRACT Main goal through this project is to have the deeply knowledge to the performance of cylindrical grinding on straightness of the specimen, an experimental investigations were planned with machining difference type of specimen materials. Detail studies were been done for the speed of grinding cutting, feed rate, type of specimen material that were use, and table speed. Attempts were made to mild steel and stainless steel with difference of strength to get the result. The objective of the project is to expose the students about the knowledge to identify machine part and performance of cylindrical grinding conventional machine. These projects are also including machine operating training session in order to make student easily understand the machine principle to produce full report writing, slide presentation and report during this project. The studies also concern the student capability through process and maintenance. All data will be evaluated done from the project lab result. The performance of the cylindrical grinding machine were related with all parameter, material structure, coolant type, machine alignment and procedure used. Lastly, after getting the result, conclusion will be able to make for complete the report. The conclusion explains about the problems occurs and problem solving. v

6 ABSTRAK Matlamat utama projek ini adalah untuk mendapatkan pengetahuan yang lebih mendalam mengenai perlaksanaan mesin pengisar membulat terhadap kelurusan bahan kajian melalui penggunaan jenis bahan kerja yang berbeza. Kajian terperinci dijalankan terhadap kelajuan mengisar, kedalaman suapan, jenis bahan kerja yang digunakan serta kelajuan pergerakan meja mesin. Percubaan dijalankan ke atas keluli lembut dan keluli tahan karat yang mempunyi perbezaan kekuatan untuk mendapatkan keputusan kajian. Tujuan projek ini adalah untuk memberikan pendedahan pengetahuan kepada pelajar untuk mengenal pasti bahagian-bahagian mesin dan perlaksanaan oleh mesin pengisar membulat biasa. Sesi latihan mengoperasikan mesin juga turut disertakan bagi memudahkan pelajar lebih memahami prinsip pengoperasian mesin serta menyediakan laporan dan membuat perbentangan untuk projek ini. Kajian juga berkenaan kebolehupayaan pelajar melalui kerja penjagaan mesin. Setiap keputusan akan dinilai melalui data dari kajian yang dijalankan. Persembahan mesin pengisar adalah berhubung kait dengan parameter, struktur bahan kajian, jenis cecair penyejuk, penjajaran mesin, dan kaedah yang digunakan. Akhir sekali, setelah mendapat keputusan, kesimpulan dapat dibuat untuk melengkapkan laporan. Kesimpulan menerangkan permasalahan yang timbul dan penyelesaian masalah. vi

7 DEDICATION Special thanks I dedicate to my beloved family especially for my father (Samdin bin Ali) and my mother (Pauziyah binti Abd. Ghani). Thanks for all your love and support. I also would like to say thanks to all my friends and class mate for contributing to the success of my project. The successful of this project cannot be achieved without all of you. Once again, thank you to all for ever thing. vii

8 ACKNOWLEDGEMENTS ALHAMDULILLAH, thanks to Allah the Almighty God for giving me strength and patience to work on my final year thesis project. I would like to take this opportunity to express my sincere and deepest gratitude to my PSM supervisor Mr Mohd Amri Sulaiman, for his guidance and opinion in the cause of completing this report. My greatest thanks to my beloved family for their prayers, support and encouragement throughout this entire period of this project. I also would like to convey my biggest thanks to all UTeM staff especially to all staff at manufacturing department for supporting me throughout my PSM Project. The knowledge and experience I gained from you all will not be forgotten. I m also obliged to everyone who had directly and indirectly involve through contributions of ideas, as well as materials and professional opinions. Last but not least, thank you very much especially to UTeM for giving me this kind of chances. Many of my projects would not be completed successfully without their help. Thank You. viii

9 TABLE OF CONTENTS Declaration Approval Abstract Abstrak Dedication Acknowledgements Table of Contents List of Figures List of Tables List of Abbreviations, Symbols, Specialized Nomenclature List of Appendices iii iv v vi vii viii ix xiii xv xvi xvii 1. INTRODUCTION Background of Project Problem Statement Objectives Scope Project 3 2. LITERATURE REVIEW Introduction to Cylindrical Grinding Machines Types of Machine Plain cylindrical grinding machine Universal cylindrical grinding machine Internal Grinding Machine Machine Specification Cylindrical Grinding Machine Part Tailstock Headstock 12 viii

10 2.4.3 Wheel head Grinding Wheel Grinding Wheel Specification Abrasives Wheel Markings Wheel Shapes and Sizes Selecting the Grinding Wheel Cylindrical Grinding Cycles Cylindrical Grinding Operations Cylindrical Grinding Work Speed Correct Work Speed Rules for Work Speed Cylindrical Grinding Traverse Speed Raw Material Selection Mild Steel SS Stainless Steel SUS Composition Mechanical Properties Straightness Straightness Factor on Cylindrical Material Cylindricity and Straightness of a Median Line MarForm MMQ44 Formtester Machines Description Introduction to Design Of Experiments (DOE) Classical and Taguchi Experiments Choice of Optimum Results METHODOLOGY Introduction Project Process Planning Machining Introduction 43 ix

11 3.3 Machining Parameters Setup Parameter setting Identification of the control factors and their level Machining Samples Machine Preparation before Machining Using Cylindrical Grinding 48 Machine Machining Workpiece Using Cylindrical Grinding Machine Measure and Analysis Data Procedure to Operate MarForm MMQ 44 Formtester Machine Result & Analysis Discussion Conclusion RESULTS & ANALYSIS Introduction Findings and Result of Straightness Analysis for Factorial Design Experiment for Mild Steel SS Significant Parameter of Straightness for Mild Steel SS Normal Probability Plot of Effects on Straightness for Mild Steel SS Pareto Chart of the Effects on Straightness for Mild Steel SS Main Effects Plot on Straightness for Mild Steel SS Interaction between Parameters on Straightness for Mild Steel SS Mathematical Model Development on Straightness for Mild Steel SS Analysis for Factorial Design Experiment for Stainless Steel SUS Significant Parameter of Straightness for Stainless Steel SUS Normal Probability Plot of Effects on Straightness for Stainless 68 Steel SUS Pareto Chart of the Effects on Straightness for Stainless Steel SUS Main Effects Plot on Straightness for Stainless Steel SUS Interaction Plot (Data Means) on Straightness for Stainless 71 x

12 Steel SUS Mathematical Model Development on Straightness for Stainless 73 Steel SUS DISCUSSION Introduction Influences in Grinding Operation The Straightness Influence factor by Work Head speed The Straightness Influence factor by Traverse Length The Straightness Influence factor by Depth of cut (wheel infeed) Influence in Types of Material Influence in Method of Measurement Problems Encounter for the Study CONCLUSIONS 6.1 Conclusions Recommendations for Future Research REFERENCES 81 APPENDICES A B Straightness Measurement Result Analysis of Variance Table xi

13 LIST OF FIGURES 2.1 Plain Cylindrical Grinding Machine Universal Grinding Machine Showing Operating Controls and 7 Principal Parts 2.3 Universal Cylindrical Grinding Machine Model OD-618 H/S Internal Grinding Machine The Tail Stock Position on Cylindrical Grinding Machine The Head Stock Position on Cylindrical Grinding Machine The Grinding Wheel Head Part Assembly The Grinding Wheel Head The Standard Marking System Chart (a & b) Abrasive Wheel Standard Marking Used For the Project Wheel Shapes Cylindrical Grinding Operations Step Wear of a Cylindrical Grinding Wheel during Cylindrical 23 Traverse Grinding 2.14 Wear Steps and Sinusoidal Displacement between Tool and 24 Workpiece 2.15 Mild Steel SS400 Raw Material Stainless Steel SUS 304 Raw Material The Illustration of Straightness Cylindricity Tolerance Specification Straightness of a Median Line Tolerance Specification MarForm MMQ 44 Formtester to Measure Straightness Flow chart of Project Methodology Flow chart of Machining Process Sequences Workpiece Dimension Band Saw Machine 49 xiii

14 3.5 Lathe Machine Universal Cylindrical Grinding Machine model OD-618 H/S MarForm MMQ 44 Formtester to Measure Straightness Clean specimens sample Setting the Centering and Tilting Parameters Running the Centering and Tilting Operations Graphical User Interface (GUI) of FORM PC software Analysis result of Straightness versus Work Head Speed, Traverse 59 Speed and Depth of Cut Mild Steel SS Normal Probability Plot of Effects on Straightness for Mild Steel 60 SS Pareto Chart of the Effects on Straightness for Mild Steel SS Main Effects plot on Straightness for Mild Steel SS Interaction Plot between Work Head Speed, Traverse Speed and 63 Depth of Cut for Mild Steel SS Analysis result of Straightness versus Work Head Speed, Traverse 67 Speed and Depth of Cut Stainless Steel SUS Normal probability plot of effects on Straightness for Stainless 68 Steel SUS Pareto Chart of the Effects on Straightness for Stainless Steel 69 SUS Main Effects plot on Straightness for Stainless Steel SUS Interaction Plot between Work Head Speed, Traverse Speed and Depth of Cut for Stainless Steel SUS xiv

15 LIST OF TABLES 2.1 Machine Specification Mechanical Properties of Grade Mild Steel SS Composition Ranges for Grade Stainless Steel SUS Mechanical Properties of Grade Stainless Steel SUS Eight-Run Classical Arrays Eight-Run Taguchi Arrays Gantt chart of Projek Sarjana Muda Gantt chart of Projek Sarjana Muda The Level of Process Parameter for Cylindrical Grinding Machine Orthogonal Array Table for Result taken Orthogonal Array Table for Experiment using Mild Steel SS Orthogonal Array Table for Experiment using Stainless Steel SUS Experimental result on Straightness for Mild Steel SS Mean Value of Straightness for Mild Steel SS400 for each 2- Way 64 Interaction 4.3 Estimated Effects and Coefficients for Straightness of Mild Steel SS (coded units) 4.4 Experimental result on Straightness for Stainless Steel SUS Mean value of straightness for Stainless Steel SUS304 for each 2- way 72 interaction 4.6 Estimated effects and coefficients for straightness of Stainless Steel SUS304 (coded units) 73 xv

16 LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED NOMENCLATURE CNC - Computer Numerical Control DOE - Design of Experiment FKP - Fakulti Kejuruteraan Pembuatan PSM - Projek Sarjana Muda UTeM - Universiti Teknikal Malaysia Melaka In/min - Inch per Minute rpm - Revolution per Minute µm - Micron Meter mm - Millimeter L s - Length of ground dimension on workpiece, in. T s - Total rough or finish stock depth removed from diameter, in. D - Original workpiece diameter, in. W - Wheel width, in. P - Traverse for each work revolution in fraction of wheel width fi - Infeed of wheel per pass, in./pass v - Workpiece peripheral velocity, in. /min PS - Manufacturer s symbol indicating exact kind of abrasive A - Aluminum Oxide 80 - Abrasive Grain size; 80 in fine grain size K - Grade; K is in medium grade. 8 - The wheel structure V - Bond type; V for vitrified 6N - Manufacturer s private marking to identify wheel xvi

17 LIST OF APPENDICES A B Straightness Measurement Result Analysis of Variance Table xvii

18 CHAPTER 1 INTRODUCTION 1.1 Background of Project As one of the many tools available to manufacturing, grinding is a distinctive technology that uses abrasives or synthetic minerals in loose or bonded form. Grinding is one of most important technologies used by manufacturing today. Used to machine and finish materials, grinding is in many cases the only method available to engineers, particularly when ceramic or new composite materials are involved. In other cases, grinding competes with other technologies and offers the most economical way to produce precision component. As compared with other machining processes, grinding is a costly operation that should be utilized under optimal conditions. Grinding is a finishing process used to improve surface finish, abrade hard materials, and tighten the tolerance on flat and cylindrical surfaces by removing a small amount of material. In grinding, an abrasive material rubs against the metal part and removes tiny pieces of material. The abrasive material is typically on the surface of a wheel or belt and abrades material in a way similar to sanding. On a microscopic scale, the chip formation in grinding is the same as that found in other machining processes. The abrasive action of grinding generates excessive heat so that flooding of the cutting area with fluid is necessary. 1

19 In Faculty of Manufacturing Laboratory in Universiti Teknikal Malaysia Melaka there were new types of machine called Cylindrical grinding machine. Hence, this report is mainly purpose to cover the study of performance of the cylindrical grinding. This study also to determine the machine capability in term of producing high accuracy and precision, the highly product finishing that can influence by straightness to the product. 1.2 Problem Statement i. Cylindrical grinding machine is a new machine in FKP laboratory. Thereby, student does not have any experience of handling the machine. ii. Student does not know the machine performance because there is no machining has done before. iii. This study will develop the appropriate parameter for cylindrical grinding machining that can practice for the student. 1.3 Objectives i. To study the performance of Cylindrical Grinding machine in FKP Laboratory ii. To analyzed the straightness factor of the finish product using Mahr Formtester MMQ44 at the university Metrology Lab. iii. To determine relationship between parameters and term of straightness factor. iv. To expose student how to research environment such as Design Of Experiment (DOE) and others. 2

20 1.4 Scope Project The scope of this project is to handling an appropriate machining operation by using the cylindrical grinding machine to study the machine performance in term of straightness factor. The Universal Cylindrical Grinder Model OD618S will be used in the study is. The material used for machining is mild steel SS400 and stainless steel SUS 304. The parameters that involve in this analysis are work head speed, depth of cut, and traverse speed are set followed to the design of experiment (DOE). Parameters such as coolant which is Pretech Cool Syn 3000 Green with a 1-3% of viscosity and abrasive wheel speed are constant. The straightness test for the specimen will be test or conduct by using the Mahr Formtester MMQ44 at the Metrology Lab and method that is will be applied to determine the straightness. 3

21 CHAPTER 2 LITERATURE REVIEW 2.1 Introduction to Cylindrical Grinding Machines Grinding machines finish parts having cylindrical, flat, or internal surfaces. The surface of the parts largely selects the grinding machines. A machine grinding cylindrical surfaces is called a cylindrical grinder. Machines designed for special functions, such as tool grinding or cutting off, are designated according to their operation. [13] Cylindrical grinding machines were used extensively in engineering workshops and industries for finish pre-machined and heat-treated components. Grinders can rough out and finish the work to fine tolerances. The surface and great accuracy can be obtained more economically on grinders than other machines. In Manufacturing Laboratory, the machine that were use for this studies is conventional Universal Cylindrical Grinder Model OD 618H/S, with variable speed table and manual wheel head in feed manufactured by SHARP Precision Machine Tools. The machine has the capability to machine both of internal and external cylindrical grinding. In the cylindrical grinding machine, the work piece is supported and rotated between centres. The head stock provides the low-speed rotational drive to the work piece and is mounted, together with the tail stock on a work table that reciprocated horizontally using the hydraulic drive. The grinding-wheel spindle is horizontal and parallel to the axis of work piece rotation, and horizontal, hydraulic feed can be applied to the wheel head in a direction normal to the axis of work piece rotation; this motion known as in feed. 4

22 A cylindrical surface being generated using the traverse motion; an operation that can be linked to cylindrical to cylindrical turning where the single point cutting tool is replace by a grinding wheel. [13] The cylindrical grinder traverses the work, to and fro, in repeated passes along the length of the diameter, and the time to traverse is found using [18]: time /pass = L s x T s x D (WP) 2fi v Where; L s T s D W P fi v = Length of ground dimension on workpiece, in. = Total rough or finish stock depth removed from diameter, in. = Original workpiece diameter, in. = Wheel width, in. = Traverse for each work revolution in fraction of wheel width = Infeed of wheel per pass, in./pass = Workpiece peripheral velocity, in. /min 2.2 Types of Machine Cylindrical grinding machines are used extensively in.engineering workshops to finish premachined and heat-treated components. Grinders can rough out and finish the work to fine tolerances. The surface finishes and great accuracy can be obtained more economically grinders than on other machines. 5

23 (a) The four types of cylindrical grinders are: i. Plain cylindrical grinding machine ii. Universal cylindrical grinding machine iii. Internal grinding machine iv. Centreless grinding machine Plain Cylindrical Grinding Machine This machine is used for grinding parallel, tapered, stepped or formed external cylindrical surfaces. They were originally designed for finishing hardened work, but their operation efficient that they are now used for finishing most types of metals and materials. Figure 2.1: Plain Cylindrical Grinding Machine 6

24 Figure 2.2: Universal Grinding Machine Showing Operating Controls and Principal Parts Universal Cylindrical Grinding Machine The universal grinding machine is very similar in construction to a plain grinding machine, except for the work head and the wheel head, both of which swivel. The work head swivels on a graduated base to 100 either side of zero. The wheel head platen not only swivels through 180 either side of zero, but is also mounted on a slide that swivels independently through 800 to 90 either side of zero. Thus, the slide can be set to the grinding angle required, and the platen swivelled through 90 presenting the wheel/face parallel to the face to be ground. A semi-universal machine in common use is very similar, except that the wheel platen and slide do not swivel independently of each other. 7