Production Process 2 - Dec 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. 1(a) Write short notes on any four:
Centre of pressure.(5 marks) 1(b) Types of Rolling Mills(5 marks) 1(c) Gear hobbing(5 marks) 1(d) Tool dynamometer.(5 marks) 2(a) Calculate and design a round pull type broach for machining hole of diameter 35H7 and length 20mm in a work piece of carbon steel.
Specific cutting force=4200 N/mm², IT7=0.025mm, Tooth rise=0.03mm cutting speed in broaching=8m/min
Draw the broach and indicate designed value.(10 marks) 2(b) Determine and design a circular form graphically, to cut a semicircular groove in the cylinder work piece whose details are given below:>br>Minimum Radius=30mm maximum Radius=20mm Assume Rake and relief angle as 10° and 6° Respectively.(10 marks) 3(a) Prove that the relationship $$2\phi + \beta -\gamma =\dfrac{\pi}{2}$$ holds good in Orthogonal cutting, where ϕ=shear angle, β=frictional angle,&gsamma;=Rake angle. Also state tour assumption.(10 marks) 3(b) Discuss any two of the following:
Different types of rolling mills.
Torque and power Calculation in rolling.
Types of Jig bushes.(10 marks) 4(a) Discuss the step of sesigning drill jig.(10 marks) 4(b)

A slab milling operation is performed under the following conditions:
Cutter diameter :100mm
Number of teeth:30
Helix angle of cutting edge:15degree
Depth of cut:7.5 mm

Cutting Speed = 30 m/min

Feed = 0.006 in/tooth

Workpiece = 20 in long and 2.5 in wide.

(10 marks) 5(a) Explain the following steps involved in the 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) A steel shaft 50mm diameter is required to be turned through distance of 300mm.On a Engine lathe.Depth of cut is 6mm and the of feed 0.2 mm/rew.Two types of tools are available for this purpose
HSS
Tungsten carbide
The following are the data available

HSS costs an average of Rs. 30 per edge and carbide costs Rs. 75 per edge. Take the operating cost as Rs. 120 per hour. Analyze the selection of the tool material based on minimum cost of machining.(10 marks) 6(b) Distinguish between :
Compund and progressive die
Drilling and millling fixture.(10 marks) 7(a) Draw the nomenclature of plain milling cutter and explain the procedure of designing a plain milling cutter.(10 marks) 7(b) Explain the following :
'C'-clamp and 'C' clamp
Open type jig and channel type jig.(10 marks)