Design And Fabrication Of Welding Jigs And Fixtures For FKP Lab.

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UNIVERSITI TEKNIKAL MALAYSIA MELAKA

DESIGN AND FABRICATION OF WELDING JIGS AND

FIXTURES FOR FKP LAB

This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering

(Manufacturing Process) (Hons.)

NAJIL BIN MAKONG B051110298 921225-12-5047

FACULTY OF MANUFACTURING ENGINEERING 2015

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DECLARATION

“I declare that this is my own work except for experts and summaries of each every one of them was me explain the source”.

Signature :………

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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) (Hons.). The member of the supervisory is as follow:

………

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ABSTRAK

Kimpalan adalah proses yang penting dalam sektor pembuatan dan pelajar FKP diwajibkan untuk belajar dan melaksanakan kimpalan robotik dan kimpalan manual. Dalam melaksanakan proses kimpalan, pelajar yang kurang kemahiran dan pengalaman akan menghadapi kesusahan seperti bahan kerja bengkok dan menyebabkan kerosakan pada meja kerja. Juruteknik juga terpaksa membuat koordinat baru setiap kali menjalankan makmal kimpalan robotik. Dalam menangani masalah ini, reka bentuk dan fabrikasi kimpalan jig dan lekapan untuk manual dan robot kimpalan untuk penggunaan makmal adalah jawapannya. Konsep reka bentuk adalah berdasarkan penemuan terdahulu oleh penyelidik lain dan data kajian yang dikumpul daripada juruteknik dan pelajar yang sudah mengambil subjek kimpalan. Empat konsep reka bentuk di lakukan dengan mengunakan sistem CAD. Reka bentuk terakhir dipilih daripada empat konsep reka bentuk dengan mengunakan kaedah pemeriksaan dan pemarkahan yang turut di bantu oleh golongan pakar. Reka bentuk terakhir ini di fabrikasi menggunakan aluminium. Setelah lekapan ini sudah di fabrikasi, satu lagi kajian lain akan dilakukan bagi mendapatkan maklum balas daripada pelanggan mengenai keberkesanan jig dan lekapan yang di buat untuk proses kimpalan. Berdasarkan jawapan responden, majority daripada mereka bersetuju yang lekapan ini boleh meningkatkan proses pembelajaran, meningkatkan kualiti kimpalan, mengurangkan gangguan haba dan penggunaan masa serta sesuai di gunakan semasa sesi bengkel.

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ABSTRACT

Welding is an important process in manufacturing sector and FKP’s students are required to learn and perform robotic and manual welding. In performing this welding process, student who is lack of welding experience will encounter difficulties such as bent workpiece and causing damage to worktable. The technicians also have to setup new coordinate system every time the robotic welding laboratory is to be conducted. In order to addressing these problems, design and fabrication of welding jig and fixture for manual and robotic welding for lab usage become a solution. The design concepts based on prior learning of other researchers and survey data collected from technicians and students who have taken subject on welding based on House of Quality approach. Three conceptual designs were done using CAD system. The final design was selected among four conceptual designs based on screening and scoring methods with assistance from experts. The final design was fabricated using aluminium. Once the fixture was fabricated, another survey was performed to seek feedback from the customer on the effectiveness of the fabricated the welding fixture. As the results, respondents said that the fixture can improve learning process, improve weld quality, reduce heat distortions and time consumptions and suitable used during lab session.

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DEDICATION

For my beloved family:

Makong bin Girah

Abda binti Muhamad

And

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ACKNOWLEDGEMNT

First of all, I would like to impress my appreciation and gratitude to Allah S.W.T for giving me the strength and ability to carry out the entire task and work given. In this great pleasure and gratitude also, I want to thanks to those who gave me the possibility to complete this report.

A special thank to my final year project supervisor Prof Madya Dr Md Nizam Bin Abd Rahman whose help, stimulating suggestions and encouragement, helped me to coordinate my project especially in writing this report. I would also like to acknowledge with much appreciation the crucial role of the staff of FKP’s Laboratory, who gave the permission to use all required machinery and the necessary material to complete the fabrication of fixture.

My special thanks goes to all of my friends that had supplied thought, advice, challenges, criticism, help and suggestion that have influenced my performance and increase my knowledge and understanding upon completing my Final Year Project. I would to appreciate the guidance given by other supervisor as well as the panels especially in our project presentation that has improved our presentation skills by their comment and tips.

I would like to conclude this section by recognizing and thanking to all of people who involved whether directly or indirectly towards completing the project.

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TABLE OF CONTENT

Abstrak i

Abstract ii

Dedication iii

Acknowledgment iv

Table of Content v

List of Table ix

List of Figure x

List Abbreviations, Symbols and Nomenclatures xii

CHAPTER 1: INTRODUCTION 1

1.1 Backgroud of Project 1

1.2 Problem Statement 2

1.3 Objectives 3

1.4 Scope of Study 3

1.5 Importance of Study 3

CHAPTER 2 : LITERATURE REVIEW 4

2.1 Welding Process 4

2.2 Jigs and Fixtures 6

2.3 Welding Fixture 8

2.4 Basic Design Considerations 11

2.5 Research Work on Welding Fixture Design 15

2.6 Product Design and Development Methodology 20

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2.6.2 Bulid House of Quality (HOQ) From the Data 21

2.6.3 Design Product Based on HOQ 21

2.6.4 Use Screening and Scoring Method to Choose Best Design 22

2.7 Summarization of Literature Review 23

2.7.1 Basic Welding Fixture Design 23

2.7.2 Design Method to be Used 26

CHAPTER 3: METHODOLOGY 27

3.1 Process Flowchart 27

3.2 Literature Review 30

3.3 Develop Survey Questionnaire 31

3.4 Execution of Questionnaire 31

3.5 Bulid House of Quality (HOQ) 32

3.6 Conceptual Design 32

3.7 Concept Selection 33

3.8 Final Design Parts 33

3.9 Fabricate 33

3.10 Conducting Survey 34

3.11 Gantt Chart 34

CHAPTER 4: RESULTS AND DISCUSSIONS 37

4.1 Market Study 37

4.1.1 Experience in Conducting Welding Process 38

4.1.2 Conformity to Develop a New Tool (Welding Fixture) 39

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4.1.4 Welding Length that Usually Used 41

4.1.5 Need of Circular Welding 42

4.1.6 Method to Load, Unload and as Holding Mechanism 43

4.1.7 Preferable Condition of Tool (Welding Fixture) 44

4.1.8 Position of Welding Fixture During Welding Process 45

4.1.9 Suitable Welding Process for the Welding Fixture 46

4.2 Summary of Result of Market Study 47

4.3 Product Specifications 48

4.3.1 House of Quality 48

4.4 Conceptual Designs . 49

4.4.1 Concept A 50

4.4.2 Concept B 51

4.4.3 Concept C 52

4.4.4 Concept D 53

4.4.5 Market Existing Product 54

4.5 Concept Selections 55

4.5.1 Concept Screening 55

4.5.2 Summary of Concept Screening Phase 57

4.5.3 Concept Scoring 57

4.5.4 Summary of Concept Scoring Phase 60

4.6 Final Design 60

4.6.1 Refining Final Design 63

4.6.2 Fabrication Planning 65

4.6.3 Estimated Budget 67

4.6.4 Bill of Materials 68

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4.7 Fabricated Product 70

4.7.1 Welding Fixture Test Run Results 71

4.7.2 Discussion About Welding Fixture Product 72

4.7.3 Welding Fixture Can Improve Learning Process 74

4.7.4 Tool Can Reduce Heat Distortions and Time Consumption 75

4.7.5 Welding Fixture Used During Lab Session 76

4.7.6 Welding Fixture Can Improve Weld Quality 77

4.7.7 Summary of Results Questionnaire 77

4.8 Summary of Results and Discussions 78

CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 79

5.1 Conclusions 79

5.2 Future Recommendations 79

REFERENCES 80 APPENDICES

A Survey Questionnaire – Welding Fixture For Lab Usage

B Survey Questionnaire – Result of Welding Fixture For Lab Usage C Turnitin Result

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LIST OF TABLE

2.1 Physical and Thermal Properties of Selected Elements 12

3.1 Activities Schedule 35

4.1 Customer Needs 47

4.2 Bill of Materials of Concept A 50

4.3 Bill of Materials of Concept B 51

4.4 Bill of Materials of Concept C 52

4.5 Bill of Materials of Concept D 53

4.6 Rating References 55

4.7 Screening Sheet 56

4.8 Rating Guidance 58

4.9 Scoring Sheet 58

4.10 Planning for Fabrications 67

4.11 Estimated Budget 67

4.12 Bill of Materials of Welding Fixture 68

4.13 Gantt chart for Fabrication Planning 69

4.14 Time Usage During Welding Process 71

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LIST OF FIGURE

2.1 Welding Process 5

2.2 Application of Robot Welding 6

2.3 Jigs and Fixtures 7

2.4 Vise as Fixture 8

2.5 Example of Welding Fixture 8

2.6 Manual Welding Fixture 9

2.7 Welding Mild Steel . 10

2.8 Hot Welding Process . 11

2.9 Example of Design From CAFD Software . 17

2.10 CAFD Verification System 18

2.11 Finite Element Analysis Method (FEM) 19

2.12 Flowchart of Designing and Developing the Product 20

2.13 House of Quality Template . 23

3.1 Process Flowchart 28

3.2 Existing Product as Benchmark . 31

4.1 The Experience of Respondents Conducting Welding Operation Before 38

4.2 The Numbers of Respondents Agree to develop a New Tool . 39

4.3 Type of Welding Process Usually Performed at Lab 40

4.4 Welding Length that Usually Performed 41

4.5 The Need to Perform Circular Welding 42

4.6 The Method to Load and Unload an as Holding Mechanism 43

4.7 The Tool (Fixture) that Respondents More Prefer 44

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4.9 The Purpose of Welding Fixture to be Made 46

4.10 House of Quality 49

4.11 Design for Concept A 50

4.12 Design for Concept B 51

4.13 Design for Concept C 52

4.14 Design for Concept D 53

4.15 Existing Product 54

4.16 Concept B Drawing by AutoCAD 61

4.17 Different Positions of Welding Fixture 61

4.18 Concept B with Four Different Parts 62

4.19 Clamping in Welding Fixture 64

4.20 Welding Fixture Product 70

4.21 Workpiece that been Weld Using Welding Fixture 71

4.22 Respondent that Agree this Tool can Improve Learning Process 74

4.23 End Users Agree a Tool Reduce Heat Distortion and Time Consumption 75

4.24 Respondents that Agree to Use Welding Fixture During Lab Session 76

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LIST ABBREVIATION, SYMBOLS AND NOMENCLATURES

BOM - Bill of Material

CAD - Computer Aided Design

CAFD - Computer Aided Fixture Design

CAFDV - Computer Aided Fixture Design Verification

CAM - Computer Aided Manufacturing

CAPP - Computer Aided Process Planning FKP - Fakulti Kejuruteraan Pembuatan

HOQ - House of Quality

GA - Genetic Algorithm

QFD - Quality Function Deployment

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1 This chapter provides summary of the intended project. It consists of background of project, problem statement, objectives, scope and importance of the study.

1.1 Background of Project

According to Rajendar Singh (2006), welding is a process of joining two different parts by fusion or heat. Welding technique can be differentiated by the types of heat supplied during the process. The heat during welding process can be supplied by chemical reaction, gases, electric resistance or electric arc. Welding is suitable for most metal and is a permanent joint. In order to get the good welding joint, many parameters or conditions must be considered. One of the considerations that can facilitate welding process is the usage of welding fixtures.

Functions of welding fixtures are to hold, locate and support the workpiece during welding process. Similar to machining fixture, welding fixture consists of the locating and clamping elements. Locators are needed to position the part, while clamps are needed to hold the part in place and prevent any possible movements during welding process (Sivarao et al, 2014).

INTRODUCTION

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2 However, there are some important considerations must be taken into account during designing the welding fixtures. Effect of heat and the generation of weld spatter during welding process are the most significant factor to be considered, because these two factors will directly influence quality of welded parts. A good welding fixture should not be deformed or undergone distortion easily. This is showing that how important is the thermal properties for material of fixture in order to maintain the accuracy and quality of welded parts. With proper control of heat distribution in the weld zone, the parts can be produced within designated tolerances with minimum or no heat distortion.

1.2 Problem Statement

Welding process is one of the processes that must be learnt by all of student in manufacturing engineering course. Usually, first year student has to conduct the arc welding process. Most of first year students are lack of basic knowledge in welding process, as the results the work table usually damaged by the electrode or the workpiece will bend during the class. Usage of welding fixtures can address this problem.

The other welding process that needs to learn by student is the application of robot welding. During the class, students are required to perform programming task for the robot movement during welding operation. The program for the welding process is the same for all students but the coordinate will change since there is no fixed position for the workpiece placement. If researcher just places the workpiece to the table, it can damage the table and probably the workpiece will bend. Again, the welding fixtures can address this problem.

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3 1.3 Objectives

The objectives of this report are:

 To design of welding fixture for usage of robotic welding.  To fabricate a welding fixtures for lab usage.

1.4 Scope of Study

This project comprised of design considerations for welding fixture. For basic arc welding, the workpiece that considered is mild steel with length of 150mm, 50mm in width and 6mm of thickness (150mm × 50mm × 6mm). The fixture to be designed is for the butt joint, lap joint and T-joint. This fixture can be used for MIG, TIG and arc welding for both manual and robotic.

1.5 Importance of Study

The importance of this study is to ease the learning process for the students during welding laboratory session. By doing some research and analysis, then design and select the suitable material and shape of the fixtures to be fabricate. Thus, these fixtures will reduce the damage of the work table, improve the quality of welding work and give the good result of welding process.

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4 This chapter provides the basic knowledge for the project finding by researchers and the methodology used by other researchers was summarized.

2.1 Welding Process

According to Hoffman (2004), the main assembly method used for joining process is welding as it provides the most efficient and economical way to join two or more individual components together. Other than welding, there are also other available joining processes, including brazing, soldering, riveting and stapling.

Young et al. (2012) stated that welding process involved melting of several pieces of base metal and the workpieces are joined together due to solidification of the pool of molten material. Filler material is always used to add materials to the weld joint. Welding is distinct from soldering and brazing where the weld joint for both latter processes is formed by melting of low-melting-point materials without melting of base metals or workpieces.

LITERATURE REVIEW

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Figure 2.1: Welding Process. (Source :< http://www.corrosionist.com/oxyfuel_gas_welding.htm/>)

Figure 2.1 above shows the acetylene feather that melt the metal to be joined together. This is what happens during most of welding process. The flame will generate heat and melt the metal so that the metal will be combined after it solidified. Distance of electrode to the material must be same along the welding process to get the better surface finishing and reduce the arising of slag.

Young et al. (2012) also mentioned that welding processes are categorized into few different types, for instance, arc welding, gas welding, robot welding, spot welding, laser welding, electron-beam welding, ultrasonic welding, gas flame welding and friction or friction stir welding. Basically, different types of welding use different types of ways to perform it. Different ways means different types of jigs or fixtures to hold it. But if it suitable, researcher can use it for same jigs and fixtures for different types of welding. But for this project, it more focus to arc welding and robot welding which commonly used in the lab for learning session.

According to Noberto et al. (2006), most of industries nowadays more prefer to use industrial robotics welding compare to manual one due to its smooth and constant operation. Besides, the robot welding can give high productivity when doing same welding process for same material and size of workpiece. This is because worker only needs to enter the codes once for many times of uses. The important in these types of welding is process parameters. This parameters influence by types and size of the materials that want to be weld. Figure 2.2 shows the example of application of robotic welding in industries.

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Figure 2.2: Application of Robot Welding. (Source :< http://robotiq.com/applications/>)

2.2 Jigs and Fixture

Jigs and fixtures in manufacturing industries can help to increase the productivity of the product. It also eliminates frequent checking, individual marking and positioning. Besides, jigs and fixtures reduce the demand of skill worker due to this particular tools can make the worker easier to machine or weld the parts. In addition, this jigs and fixtures is interchangeability which means that no need for selective assembly. Lastly, this can reduce the cost and reduce the scrap. A fit jigs or fixture can make sure reducing of scrap of material. (P.H Joshi, 2003).

Sivarao et al. (2014) stated that fixture is one of a tool that used in production to hold, locate and support the workpiece. Overall, that were fixtures that used for machining and welding process. Jigs and fixtures can ease the work for the production line and also reduce the cost. Jigs and fixtures are production tools used to accurately manufacture duplicate and interchangeable parts. Jigs and fixtures are specially designed so that large numbers of components can be machined or assembled identically, and to ensure interchangeability of components. Figure 2.3 shows example of jigs and fixtures that usually found in the market and used in laboratory or workshop.

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Figure 2.3: Jigs and Fixtures. (Source :< http://www.tradeindia.com/fp300455/Jigs-Fixtures>)

According to Campbell (1994), fixture as a tool and was established to holds things. Fixture used to make or examine manufactured parts for industry. Fixtures might use to hold workpiece that going to into a stamping process, load them into a press, hold them during pressing, remove them afterward, hold them during assembly to other parts, and hold them during inspection. This clearly means that the fixtures have many usages and also can use to other purpose.

Andrew et al. (2004) mentioned that fixtures are normally designed for a definite operation to process specific workpiece and designed and manufactured individually. Jigs are similar to fixtures instead they also used to guide the cutting tools in drilling or boring operations. This means that jigs also need fixtures while fixtures not necessarily need a jig to perform. Generally all fixtures will consist of locators, clamps, support and also fixtures body. Figure 2.4 shows the example of vise that widely found at the workshop or laboratory since it can be used for many purpose.

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Figure 2.4: Vise as Fixture. (Source :< http://www.mitchellgolf.com/Repair-Tools>)

2.3 Welding Fixture

Jigar et al. (2013) stated that jigs or fixture in welding can influence in cost, quality and productivity. Besides, jigs or fixture can decrease the distortion that happen in the welding process. Welding fixture also can reduce manufacturing lead time for welding, holding parts, and positioning with reduction of production loss of welding. This could make student to finish their welding faster than usual. This also can improve the welding experience to student for their knowledge in the future or for working experience. Figure 2.5 below shows the example of welding fixture that used in one of workshop.

Figure 2.5: Example of Welding Fixture. (Source :< http://baedesignanddevelopment.com/weldfixtures>)

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9 Sivarao et al. (2014) stated that for welding fixtures, it is used to decrease or eliminate distortion problem that happen during welding process due to large amounts of heat used. There were 3 types of welding fixtures that commonly used in industries such as tracking, welding and holding. Tracking is used to hold pieces of material together in several places until they are tack welded together. Tack means to join two pieces of material together. This is to avoid warping or distortion when welding process is complete.

For welding types, it is used to keep parts of an assembly in position and commonly for parts that are to be weld together. Basically, it is much heavier than tacking tools because it has to resist the added forces caused by the heat within the parts. Lastly, for holding types, it recently used after tack welded assemblies for finishing process. It should be rigid enough to avoid distortion and warping.

According to Campbell (1994), welding fixtures used to position and hold two or parts together while they are joined. A good welding fixture usually can also be used for brazing or soldering since the process is similar and the differences will not affect a fixture designed to hold parts undergoing them. He also stated that the fixture that to be designed must be accurate since the cost to build is expensive. Figure 2.6 below shows the welding fixture that surely expensive but can increase the productivity with the accurate and easy to use.

Figure 2.6: Manual Welding Fixture. (Source :< http://www.royalengineers.co.in/assembly>)

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