B.E./B.Tech. DEGREE EXAMINATION, MAY/JUNE 2009. Seventh Semester Mechanical Engineering ME 1009 — DESIGN OF JIGS, FIXTURES AND PRESS TOOLS (Regulation 2004) (Common to B.E. (Part-Time) Sixth Semester -Mechanical Engineering Regulation 2005) Time : Three hours Answer ALL questions. PART A — (10 x 2 = 20 marks) 1. Distinguish between jigs and fixtures. 2. List the standard parts used in jigs and fixtures fabrication. 3. What is the primary function of linear bushing? 4. How can the relation of the jig plate and vise jaw be accurately controlled? 5. What are boring fixtures? How do you classify them? 6. What are welding fixtures? State the general purpose of a welding fixture. 7. What factors should be considered for selecting an appropriate press for a given job? 8. What is the function of a stripper? 9. Distinguish between a compound die and a combination die. 10. Find die clearance range for shearing a 2 mm thick aluminum sheet. PART B — (5 x 16 = 80 marks) 11. (a) What is meant by clamping? Explain the principles involved in the design of clamps? Or (b) Explain briefly the various types of errors accounted for in jigs and fixtures design. 12. (a) Design and draw a suitable drill jig to drill 4 holes of 5 mm diameter at 70 PCD on ϕ 120 mm diameter 60 mm thickness mild steel plate. Or Maximum : 100 marks
(b) Sketch and explain air operated drilling jig components. 13. (a) Design a broaching fixture to perform broaching operation on sides of a square block of size 50 mm x 50 mm. Or Page 1 of 20
Describe the various classification of milling fixtures. Describe
(a) How are the dies classified according to their construction? the different types.
Or (b) Find the total pressure, dimensions of tools to produce a washer 50 mm outside diameter with a 24 mm hole, from material 4 mm thick, having a shear strength of 360 N/mm2. 15. (a) Design and draw a suitable die for 25 mm x 20 mm mild steel plate with a 8 mm hole in the centre. Stock thickness is 0.75 mm Or (b) A shell shown in figure below has a height of 48mm and diameter of 48 mm. The corner radius 2 mm and sheet thickness 1 mm. Material : mild carbon steel. Design a die for drawing operation.
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B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2008. Seventh Semester (Regulation 2004) Mechanical Engineering ME 1009 — DESIGN OF JIGS, FIXTURES AND PRESS TOOLS (Common to Automobile Engineering) (Common to B.E. (Part-Time) Sixth Semester Regulation 2005) Time : Three hours Maximum : 100 marks
(Approved design Data book is permitted) Answer ALL questions. PART A — (10 x 2 = 20 marks) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Name any two materials commonly used in jigs and fixtures and their Hardness range. Write any two requirements of clamping devices. Distinguish between the channel and box jigs? Illustrate the working of an automatic drill Jig. Name any four essential features of a milling fixture. How can a lathe fixture be clamped to the lathe? List out the main parts of a power press. How will you select the proper material for press tools? What is the effect of excessive clearance upon die-cut metals? Differentiate between a cutting die and forming die. PART B — (5 x 16 = 80 marks) 11. (a) List any four types of jigs and fixture construction? State the advantages of each and discuss the relative merits of each. Or (b) Explain the advantages to be obtained from the use of pneumatic and hydraulic clamping devices. (a) What is the primary function of a linear bushing? List out any four types of drill bushes with its method of fixing and locking. Or (b) Sketch and explain any eight parts of a Box jig with suitable diagram. (a) (i) (ii) Illustrate the working of a lathe fixture. Illustrate the working of Gang milling fixture. Or Page 3 of 20