Production Process 2 - May 2013

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.

Attempt in brief any four:-

1 (a) What is the six point location principle?(5 marks) 1 (b) Discuss assumptions made in Merchants circle diagram.(5 marks) 1 (c) Rolling defects.(5 marks) 1 (d) Types of coolants.(5 marks) 1 (e) Worm working.(5 marks) 2 (a) What error is caused due to improper orientation of V-location.(7 marks) 2 (b) Sketch the various types of jig feet.(6 marks) 2 (c) How can a lathe fixture be clamped to the lathe.(7 marks) 3 (a) An orthogonal cutting of steel is done with 10⁰ rake tool, with a depth of cut 2 mm and feed rate of 0.20 mm/rev. The cutting speed is 200 m/min. The chip thickness ratio is 0.31. The vertical cutting force is 1200N and horizontal cutting force is 650N. Calculate from the Merchants theory, the various work done in metal cutting and shear stress.(10 marks) 3 (b) How is the metal removed in metal cutting? Explain the process by giving any simple model to explain metal removal process.(10 marks) 4 (a) A 600mm long job of diameter 150mm of AlSI 4140 steel is to be turned with a depth of cut of 1.5mm and feed rate 0.25mm/rev, The following data is applicable for the problem:-
Labour cost per hour = Rs.12
Machine overhead per hour = Rs.40
Grinding cost per hour = Rs.15
Grinding machine overhead per hour = Rs.50
Idle time = 5minutes
Taylor's tool life equation is given by,
VT^0.22 = 475
The operation can be carried out using tungsten carbide tools either as brazed tool or throwaway tool.
For brazed tool,
Initial cost = Rs.60
Grinding time = 5minutes/edge
Tool changing time = 2minutes
9, Grinding per tool before salvage.
For throwaway tips,
Initial cost = Rs.40
Tool change time = 1.5minutes
Total cutting edges = 8
Find the optimum cutting speed, tool life and the cost of the operation for both the brazed tip and throwaway types using the criteria of the minimum production cost, and maximum production rate.(15 marks) 4 (b) Explain with neat sketches any one type of lathe tool dynamometer.(5 marks) 5 (a) Explain steps in designing form tool.(6 marks) 5 (b) Explain steps in designing broach tool.(9 marks) 5 (c) Write note on cutting fluids.(5 marks) 6 (a) A cup of 105 mm inside diameter and 90 mm deep is to be drawn from steel sheet 1mm thick. Determine the blank diameter and suitable punch diameter for the first draw. Give the probable dimensions of the cup obtained of the cup obtained from the first draw and estimate the press capacity.(10 marks) 6 (b) Sketch a sectioned view of blanking di and label on it. Clearance, straight and angular clearance.(10 marks) 7 (a) Sketch and explain different types of rolling mills.(10 marks) 7 (b) Short note on following:-i) Extrusion
ii) Rotary swaging(10 marks)