DESIGN AND IMPLEMENTATION OF SPOT WELDING TRAINER FOR BODY SHOP ASSEMBLY LINE

Transcription

1 GLOBAL ENGINEERS & TECHNOLOGISTS REVIEW DESIGN AND IMPLEMENTATION OF SPOT WELDING TRAINER FOR BODY SHOP ASSEMBLY LINE MUKHTAR 1, M.A.F.M., RAVI 2, S., ABIDIN 3, Z.F.Z. and SIMON 4, S. 1, 2, 3, 4 International College of Automotive DRB-HICOM Automotive Complex, Peramu Jaya Industrial Area P.O. Box 8, Pekan, Pahang, MALAYSIA 1 fatah@icam.edu.my 2 s.ravi@icam.edu.my ABSTRACT The main purpose of spot welding trainer kit is used for the students during the body shop practical class. The scopes of this project is to develop a spot welding jig as a trainer kit, to hold the parts together during spot weld process (as safety tool for students/operators) and to facilitate the students when focusing on the welding point of the body parts. This paper also involve the jig patents review process and the preliminary design construction. The spot welding trainer kit also proves that it can expose the students to experience and discover the actual welding point on actual body and body parts similar to the actual process in body shop assembly line. A steel plate is clamped to the spot welding trainer kit and is used as a test plate to make the students familiar with the turning angle of spot welding gun. Keywords: Welding Trainer, Body Shop, Spot Welding Jig, Jig Patent, Turning Angle. Article History: Received 18 August 2013, Accepted 11 January INTRODUCTION Welding jig is equipment used to locate and firmly hold a work piece together during a welding process. It has special type of frame used to establish the correct position of structural parts on the body prior to welding them. The welding jig is used in metal fabrication to perform repetitive assemblies. With the aid of a jig, semiskilled personnel can perform complicated assemblies guided by the jig. A teaching aid is any piece of equipment that can be used to help the students to learn (Nickerson and Zodhiates, 2013). Examples of teaching aids include the blackboard, a tape recorder, a CD player, computers, projector and others (Giza and Kosheleva, 2012). The jigs designs consists of a number of different approaches such as jigs planning, jigs layout design, jigs element design, tool body design, etc. The Figure 1 shows a jig design procedure, this procedure must be followed to ensure the development of a jig is correct. The jigs although they may be developed in parallel and not necessarily as a series of isolated activities in actual execution. Every jigs design must have three basic jigs concepts. They are Jigs layout is an embodiment of the concepts in the form of a spatial configuration of the fixture. The Jigs element design is concerned with the concrete details of the locators, clamps and supports and the tool body design produces a structure combining the fixture elements in the desired spatial relationship with the machine tool (Chiu and Kremer, 2011). Jigs planning Jigs layout Data and design criteria: Product Operation Equipment Operator Jigs element design Jigs body design Evaluation & approval, completion of design Figure 1: Procedure of jigs design. G.L.O.B.A.L E.N.G.I.N.E.E.R.S..&.-.T.E.C.H.N.O.L.O.G.I.S.T.S R.E.V.I.E.W 1

2 2.0 JIG DESIGN In the design of a jig, a definite sequence of design stages are involved. It can be divided into three methods or principals. They are locating methods, locating principals and clamping principals. Locating methods is the stage where information about locating the work piece surfaces for the purpose of performing a welding operation. Locating principals involve the consideration of basic principal of locating, referencing and repeatability. The clamping principals is where the locating and preventing movements of the work piece as the first basic function of a jig (Kakish et al., 2000). Jigs planning is to conceptualise a basic jig configuration through analysing all the available information regarding the material and geometry of the workpiece, operations required, processing equipment for the operations and the operator (Gnanaguru et al., 2010; Hargrove, 1995). The following outputs are included in the jig plan such as jigs types and complexity, number of workpieces per fixture, orientation of workpieces within fixture, locating datum faces, clamping surfaces and support surfaces. Generation of jigs layout is to represent the jigs concepts in a physical form. The following outputs are included in the jigs layout. Positions of locators, positions of clamps, positions of supports, if any, type of locators, Type of clamps, type of supports and clamping forces and sequence. Jigs element design is either to detail the design drawings on paper or to create the solid models in a CAD system of the practical embodiment of the conceptual locators, clamps and supports. It is possible to use standard designs or proprietary components. The following outputs are included in the jigs element design. During the procedure of jigs design some design criteria must be observed they are the design specifications, factory standards, easy of use, safety and economy (Maropoulos and Ceglarek, 2010). 3.0 PROBLEM STATEMENT At body shop laboratories, there is a common problem in conducting training for spot welding process. This is because of the limited parts problem such as the existing jigs cannot fully be used together with the test plates. The existing parts are very limited and quite expensive for practical training purpose. This will affect the quality of student learning. This proposal is discuss the problem related to body shop laboratory and come out with a suggestion of designing a teaching aid for spot welding. The Figure 2 shows the existing X Type gun. The problem is X type gun cannot perform spot welding due to difficult angle. The Figure 2 shows the C type gun. The C type gun can done spot welding but the gun is on the other station. So moving the gun is difficult. Figure 2: Type of gun for spot welding X, C. 4.0 PROPOSED METHOD This design is generally related to process equipment for spot welding of a test plate supported by nuts and bolts. Typical methods of spot welding involve placing actual parts on a jig. The parts must be separated from the jig after it has been welded together. The welded parts cannot be used on the same jig repeatedly. The parts for the jig are shown in Figure 3 and they are very limited. The solution for limited parts problem is by using test plate for spot welding learning process is shown in Figure 3.Various kinds of ways used in effort to secure the test plate on a jig. However, conventional jig are not suitable for securing a test plate for spot welding process. The test plate dimensions are taken as Mild steel plate in 60mm X 200mm and 100mm X 600mm. The Figure 4 shows the welding process and Figure 4 shows the test plate securing mechanism. The embodiment of this welding jig is relatively light weight which is easy to carry by one man and is highly portable. It has the characteristic of a jig such as support, clamp and jig body. The fastener wills firmly pressing the flanges structure and the test plate separately. 2

3 Figure 3: Part used for welding, Test plate. Figure 4: Welding process, Test plate securing mechanism. The C-clamp is typically used to hold a wood or metal work piece, and is often used in, but is not limited to, carpentry and welding. These clamps are called C clamps because of their C shaped frame, but are otherwise often called G-clamps or G-clamps. The advantages of the clamp are provide enhance and safer grip, providing sensitive handling measure, made from composite material, can be back off where most of the quick clamps can only be fully released, disadvantages, expensive and slow movement. The Figure 5 shows the G clamp. Locking welding clamp designed to hold round, angled, or flat. The Figure 5 shows the Locking pliers. The advantages are providing enhance grip, quick release. The disadvantages are Difficult to use. The bolt and nut is a hardware device that mechanically joins or affixes two or more objects together. The bolt and nut is shown in Figure 5(c). The advantages of the bolt and nut is provide enhance grip, fastened and unfastened repeatedly and cheap. The disadvantages are hard to use. The objective of the research work is to design a new welding jig as a teaching aid and reduce limited parts problems. The scope of the research work is technical review jigs patent, study of jigs and develop welding jig as a teaching aid. (c) Figure 5: G clamp for welding, Locking plier, (c) Bolt and nut. 3

4 By following design drawing, a prototype of a jig has been made is shown in Figure 6. The location of the clamp first point is shown in Figure 7. The location of the clamp second and third point is shown in Figure 7 and Figure 7(c). The location of the clamp fourth point is shown in Figure 7(d). Figure 6: The prototype. (c) (d) Figure 7: The location of the clamp points First, Second, (c) Third, (d) Fourth. 5.0 FABRICATION AND TESTING After reviewing the prototype, the actual jig is fabricated according to the drawing and characteristic is shown in Figure 8. The finished welding jig is shown in Figure 8. The advantages are easy to carry and store, lightweight and using only a small space. Spot weld testing showed that the teaching aid is secure and safe to use. Every spot welding gun can be used during this testing with a lot of different angle of spot welding. The spot welding testing is shown in Figure 8.The improvement is made due to the fastener need to use 10 mm spanner to tighten the jig. By adding 19 mm washer on top of the bolt, the fastener can be more easy to use without using 10 mm spanner to tighten the jig. The Figure 9 shows the overall welding process using the jig for spot welding. 4

5 Figure 8: Finished welding jig, Spot weld testing. Figure 9: The overall welding process using the jig for spot welding 6.0 CONCLUSION The objective of this research project is to design a new teaching aid to help instructor teach their student and to reduce limited parts problems. By designing a new teaching aid, it proves that the teaching aid is safe to use and can help the students to experience the actual welding point on actual body and body parts similar to the actual process in production line at body shop assembly. By using a test plate that is clamped to the new teaching aid, it can help to reduce parts problem. The advantages of this welding jig are it can be located in many different angles on a body and parts. The test plate can be place in vertical or horizontal angle. Student can use the X type welding gun and the C type welding without having any trouble of handling the gun. Spot weld testing showed that the teaching aid is secure and safe to use. Every spot welding gun can be used during this testing with a lot of different angle of spot welding can help the students to experience the actual welding point on actual body and body parts similar to the actual process in production line at body shop assembly. REFERENCES [1] Chiu, M.C. and Kremer, G.E.O. (2011): Investigation of the Applicability of Design for X Tools During Design Concept Evolution - A Literature Review, International Journal of Product Development, Vol.13, No.2, pp [2] Giza, B. and Kosheleva, O. (2012): Tools, Tasks, and Strategies: A Conceptual Framework for Using Free and 5

6 Open Source Software in K-12 Learning Activities. Proceedings of Society for Information Technology & Teacher Education International Conference, pp [3] Gnanaguru, R., Puvaneswari, K., Mallick, J., Jegadheesan, C., Sivakumar, V. and Devadasan, S.R. (2010): An Investigation into 6-S Auditing in an Aircraft Company, International Journal of Productivity and Quality Management, Vol.6, No.4, pp [4] Hargrove, S.K. (1995): A System Approach to Fixture Planning and Design, International Journal of advanced Manufacturing Technology, Vol.10, Iss.3, pp [5] Kakish, J., Zhang, P.L. and Zeid, I. (200): Towards the Design and Development of a Knowledge-Based Universal Modular Jigs and Fixtures System, Journal of Intelligent Manufacturing, Vol.11, Iss.4, pp [6] Maropoulos, P.G. and Ceglarek, D. (2010): Design Verification and Validation in Product Lifecycle, CIRP Annals - Manufacturing Technology, Vol.59, Iss.2, pp [7] Nickerson, R.S. and Zodhiates, P.P. (2013): Technology in Education Looking Toward 2020, Routledge, New Jersey, USA. 6