Design and development of JIG for Making Anchor ...

International Journal of Applied Engineering Research, ISSN 0973-4562 Vol. 10 No.83 (2015) © Research India Publications; httpwww.ripublication.comijaer.htm

Design and development of JIG for Making Anchor Head in three Axis Vertical Milling Machine 1

Palani.S 2Johnstephen R 3Logesh.H 4Selvam M 5Kaushik Mandal

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Associate Professor, Department of Mechanical Engineering, Vel Tech Multitech, AVADI, Chennai-62, India. Assistant Professors, Department of Mechanical Engineering, Vel Tech Multitech, AVADI, Chennai-62, India. 5 Final year, Department of Mechanical Engineering, Vel Tech Multitech, AVADI, Chennai-62, India.

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ABSTRACT - Here this project work deals with the design and development of an anchor head. Intend of this project is to design a jig for making an anchor head. In some machining operations the tool is required to be guided by means of another device and in some cases the job is required to be held in the fixed position for this the device which guides the tool is called jig and the device which holds the job is called fixture. The anchor head is designed for a specific size. All machine process is being carried out via CNC three- axis milling machine (Fanuc control). The final jig obtained after milling has high accuracy and surface finish. The fabricated jig has a reduced cost of manufacturing increasing company’s productivity rate and quality. Key words: Jig; Fixture; Anchor head; Fanuc control . 1.

INTRODUCTION

An anchor head is made of forged steel or mild steel, with shape and dimension allowing a uniform stress distribution on the structure and a correct housing of the anchorages and wedge system for the eventual protection gap of the anchor head system. Free length is the part of anchor between the bond and anchor head, in which the tension element undergoes it’s lengthening during tensioning operations in this zone strands are protected in a sheath, through that it also protects itself from corrosion and stray currents. Bond length is the part of the anchor transmitting the tensile stresses to the ground by means of cemented grout, assuring adherence between the tension elements and bore hole. To increase their cement steel adherence, strands are suitably shaped, by means of spacers in a sinusoidal form with loops and knots. To make anchor head insertion into the borehole easy and has threading face to reduce friction. The jig and fixture parts and component are divided into following categories: (a) Locating components, (b) Clamping mechanisms,(c) Tool guiding components, (d) Support components, (e)Body of fixture, (f) Fixing components for fixture, (g) Auxiliary mechanisms, (h) Operating elements, (i) Power mechanisms, (j) Miscellaneous components.. Paper explored the technology of intelligence and optimization in the process of the jig and fixture design. [1]. Fixture layout and the clamping forces optimization become two important aspects in fixture design. The positions of locators and clamps should be properly selected, and the clamping forces should be calculated so that the work piece deformation is minimized and uniformed. In this paper, a dual optimization method is presented for the fixture layout design and dynamic clamping forces optimization. The objective is to minimize the maximum elastic deformation of the machined surfaces and maximize the uniformity of the deformation [2]. Optimum design approach is to provide comprehensive analyses and determine an overall optimal design to fulfill the multi-functional and high performance

fixturing requirements [3]. Jigs and fixtures “eliminate the necessity of a special set up for each individual part.” heobserved that once a jig or fixture is appropriately set up, that any number of duplicate component scan be readily produced without additional set up motion of another tool [4]. They observed that the primary purpose of a jig is to provide repeatability, accuracy, and interchangeability in the manufacturing of products. Although the most common jigs are the drilling and boring jigs, they are all identical except for the shape, type, and the position of the bushings for drilling or boring [5]. The basic fixture design principle, the flow chart of the design steps to design the weld fixture has been stated and 3-2-1 principle of location has been explained in this paper that has been considered while designing the fixture [6]. The main advantages of Jigs and fixtures are “durability, setup reduction, improvement in productivity, reduced decision making in operation selected from the standard components [7]. Experiments have been conducted successful on computerized prediction of heat distribution in welding tool and they have used the expressions of thermodynamics to arrive at the heat transfer efficiency and heat energy [8]. The influence of the clamping force on the structural integrity of the GTAW welded work piece. The paper has been studied and considerable clamping force calculations have to be carried out in designing of the welding fixture LIFE OF AN ANCHOR depends on its length of time and on environmental aggressiveness, anchors can be classified as: TEMPORARY: when they are applied to temporary structures to contrast the force that rises during the structure erection, but they are not present after completion of structure. PERMANENT: when their action is requested for an important period in the life of the structure to which they are applied, in these case the anchor protection must be total. The Anchor service life is shown in Fig. 1.

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International Journal of Applied Engineering Research, ISSN 0973-4562 Vol. 10 No.83 (2015) © Research India Publications; httpwww.ripublication.comijaer.htm

Fig. 1: Anchor service life CORROSIVE PROTECTION DECISSION TREE In cohesive soil’s it’s important to increase friction between the ground anchor’s body and the surrounding soil; in this case grouting is performed by means of pipe with valve equipped with manchettes placed at variable distance depending upon the characteristics of soil (30, 50, 100 cm), with the aim to have the possibility to make localized pressure grouting operations in different phases and eventually to repeat grouting after tensioning, in case of lack of adherence with the soil. Protection of all parts of anchor head is assured by: Free length, bond length, anchor head. External protection of anchor head is assured by: Concrete seal and metallic cap. STRUCTURE OF AN ANCHOR HEAD SYSTEM This project is to design a jig for making an anchor head. In some machining operations the tool is required to be guided by means of another device and in some cases the job is required to be held in the fixed position for this the device which guides the tool is called jig and the device which holds the job is called fixture. The anchor head is designed for a specific size. The structure of the Anchor head is shown in Fig. 2.

Fig.2: Structure of the Anchor head 2.

MATERIAL SELECTED

Material selected for this work is mild steel. The mechanical properties of mild steel as shown in Table 1. Table 1: Mechanical properties of mild steel

Malleable and ductile and therefore bends fairly easy.

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International Journal of Applied Engineering Research, ISSN 0973-4562 Vol. 10 No.83 (2015) © Research India Publications; httpwww.ripublication.comijaer.htm

3.       3.1

METHODOLOGY

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Observation Analysis Choosing a particular area Identifying the problem Identifying the solution Designing

TIME CONSUMPTION: By comparing time for manufacturing of an anchor head between the method of JIG and VMC is listed below:

3.2

Difference in finishing the work by JIG is of 11.02 min.

ANCHOR HEAD SPECIFICATION

OUTER DIAMETER NO.OF STRANDS STRAND DIAMETER THICKNESS OF WORK

: : : :

180mm 19 Holes 10mm 10 Thk

3D VIEW OF JIG

The 3D view of JIG is shown in Fig. 3.

Fig. 3: 3D view of JIG The jig of anchor head is designed via CATIA V5 software. 3.3

CNC PROGRAM USED FOR FABRICATION

The fabrication of this work is done using CNC 3 axis vertical milling machine. Fanuc control is used for programming. (Prototype programming for making 4 holes, depth 5cm) O1111; G17G40G43G54G64G90G00H1Z50; M03S1200; X-40Y-40; Z3; G98G83Z-5Q0.3R1F150; X-40Y40; X40Y40; X40Y-40; G00G80Z50; M30; (Program for circular surface finishing) O1212; G17G40G43G54G64G90G00H1Z50; M03S1200; G01Z-0.5F150; G02G90X-45Y0; G00Z50; M30;

RESULT AND DISCUSSION

COST COMARRISON: Comparison of cost of manufacturing is tabulated below: So, 190 rupees is being saved by JIG method. PRODUCTION RATE: VMCNumber of anchor head produced/day= 14 pieces Number of anchor head produced/ year= 5110 pieces Cost of 5110 pieces= Rs.2135980 JIGNumber of anchor head produced/day= 19 pieces Number of anchor head produced/ year= 6935pieces Cost of 5110 pieces= Rs.1581180 DIFFERENCE BETWEEN BOTH METHODS: Production increased by using JIG= 1825 pieces Production cost saved by using JIG= Rs.554800 As after comparing both method of production, rate of manufacturing increased by 35.7% CONCLUSSON The designing and fabrication of anchor head is successfully achieved. Due to which production through JIG has increased when compared with VMC. This JIG gives better surface finishing and quality to the anchor head and satisfies the customer needs. Through this project further we can modify and design to fabricate multi- purpose jig and fixtures. REFERENCES [1] Zhang Yuru, Peng Gaoliang “Development of and integrated system for setup planning and fixture design in CAPP” International Conference on Advanced Intelligent Mechatronics Monterey, California, USA, 24-28 July, 2005J. Newman, Electrochemical Systems, 2nd ed., Prentice-Hall, Englewood Cliffs, NJ, 1991. [2] Yun-Hui Liu “Optimal Fixture Layout Design for 3D Work pieces” Proceedings of the 2004 IEEE International Conference on Robotics 8 Automation New Orleans, LA April 2004. [3] Jing Yu, Ting Wen, Qingxi Hu “Research on Automatic Planning of Main Clamping Points in Rapid Fixture Design System” 2010 Seventh International Conference on Fuzzy Systems and Knowledge Discovery (FSKD 2010). [4] Meduettaxila (2012). “Jigs and Fixtures Module” https://2k9meduettaxila.files.wordpress.com/2012/04/scan jigs- and-fixtures.pdf [Accessed 22 May 2015]. [5] Nanthakumar, K. and Prabakaran, V. (2014). “Design and Fabrication Testing of Combined Multipurpose Jig and Fixture” IOSR Journal of Mechanical and Civil Engineering. www.iosrjournals.org.

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International Journal of Applied Engineering Research, ISSN 0973-4562 Vol. 10 No.83 (2015) © Research India Publications; httpwww.ripublication.comijaer.htm

[6] Iain Boyle , Yiming Rong , David C. Brown A Review and Analysis of Current Computer-aided Fixture Design Approaches ELSEVIER, Robotics and Computer – Integrated Manufacturing 27 (2011) pp. 1-12. [7] Mechnol (2015). “Applications of Jigs and Fixtures” [Online] http://www.mechnol.com/applications-of-jigsandfixtures. html [Accessed 11 July 2015]. [8] M. Estrems, H. T. Sanchez and F.Faura “ Influence of Fixtures on Dimensional Accuracy in Machining Processes springer2003,pp384-390.

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