Production Process 2 - May 2016
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 any four of following
1(a) Distinguish between gear hobbling and gear shaping.(5 marks) 1(b) What is NC, CNC, DNC? State the advantages and limitations of Nc systems over conventional system.(5 marks) 1(c) Explain the mechanism of chip formation(5 marks) 1(d) Explain with neat skecth any one type of lathe tool dynamo-meter.(5 marks) 1(e) Discuss tool angles in ASA system with neat sketch.(5 marks) 2(a) Write a manual part program for finishing a forged components as shown fig. Assume the speed and feed on the turning center are 200 rpm and 0.35 mm/rev. Assume 1mm material is to be removed radially from external diameter.(10 marks) 2(b) While machining steel with a tool of [0-10-6-6-75-1] ORS shape following observations were made.
(i) Spindle speed 400 rpm
(ii) Work diameter 60 mm
(iii) Depth of cut 2.5 mm
(iv) Tool feef rate 80mm/min
(v) Cut chip thickness 0.40 mm
Determine ship thickness ratio, shear plane angle, Dynamic shear and Theoretical continuous chip length per minute.(10 marks) 3(a) Derive the original merchants theory along with diagram and assumption.(10 marks) 3(b) Discuss in detail various factors affecting the tool life.(10 marks) 4(a) The following equation of tool life is given for turning operation
VT0.13 f0.77 d0.37 = C
A 60 minute tool life was obtained while cutting at V=30m/min, f=0.30 mm/rev and depth of cut, d=0.5 mm calculate the change in tool life if the cutting speed, feed, depth of cut are increased by 20% individually and also taken together. What will be their effect on tool life.(10 marks) 4(b) Discuss cutting tool materials with their properties and applications.(10 marks) 5(a) Discuss various Broach terms with neat sketch.
Write the formulas for following elements.
(i) Tool pitch
(ii) Rise per tooth
(iii) Total no of teeth in a broach
(iv) Effective length(10 marks) 5(b) What are the functions of cutting fluid? Explain different types of cutting fluid.(10 marks)
Write short notes on (any four)
6(a) Form tool design(5 marks) 6(b) Types of chips(5 marks) 6(c) Lapping and honing(5 marks) 6(d) Classification of shapes(5 marks) 6(e) Co-ordinate measuring machine(5 marks)