Production Process 2 - Dec 2011

Mechanical Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Write short note on following:-

1 (a) Lathe tool dynamometer.(5 marks) 1 (b) Types of bushes.(5 marks) 1 (c) Force analysis & power calculation in drilling.(5 marks) 1 (d) Types of chips.(5 marks) 2 (a) Design and sketch a suitable die to produce 10,000 pieces of M.S. work piece of diameter 35mm and 2mm thick. The material is having shear strength of 400N/mm². Assume suitable data if necessary. Write the necessary design steps.(10 marks) 2 (b) What factors should be considered for selecting appropriate press for a given job? Discuss the method of reducing cutting forces in press tool with neat steps.(10 marks) 3 (a) Prove that the relationship
2θ + β + γ = π/2
holds good in orthogonal cutting, where θ= shear angle, β= friction angle, γ= rake angle. Also state your assumptions.(10 marks) 3 (b) During orthogonal machining with rake angle 10⁰ and uncut thickness 0.125mm, the values of F_t and F_c are found to be 217N and 517N respectively. Average chip thickness=0.43mm, width of chip=2mm, cutting speed=120m/min. Compute: chip thickness ratio, shear angle, resultant force, shear force, normal compressive force, frictional force, merchant?s constant, cutting power consumption, shearing power consumption and frictional power consumption(10 marks) 4 (a) Discuss the different cutting tool material with their advantages and limitations.(10 marks) 4 (b) Explain planetary and cluster rolling mills with neat sketches.(5 marks) 4 (c) Write short note on "Mechanism of Rolling Process"(5 marks) 5 (a) Explain the various steps involved in design of circular pull type broach. Draw the neat sketches.(10 marks) 5 (b) Compare jigs and fixture and explain locating and clamping elements used in jigs and fixtures.(10 marks) 6 (a) Explain thread rolling and rolling defects.(7 marks) 6 (b) Explain the design principles for turning fixtures.(5 marks) 6 (c) Compare compound and progressive die with neat sketches.(8 marks) 7 (a) A 200 mm long and 30 Mm bar is being turned on lathe with a feed of 0.25 mm/rev. The operating cost is 5 paise/min while tool cost is Rs.1 per cutting edge. Tool changing time is 1 min. for each cutting edge. Compare the machining cost per component while operating under most economical condition for following materials:-