Production Technology - Jun 2014

Mechanical Engineering (Semester 8)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What are the main characteristics of cutting tool materials.(3 marks) 1 (b) Explain in brief Taylor's relationship for cutting speed-tool life.(4 marks) 1 (c) During an orthogonal machining ( turning) operation of C-40 steel, the following data were obtained.
(1) Chip thickness = 0.45mm
(2) Width of cut = 2.5mm
(3) Feed = 0.25mm/rev
(4) Tangential cut force = 1130N
(5) Feed thrust force = 295N
(6) Cutting speed = 2.5m/s
(7) Rake angle = 10°
Calculate
(1) Force of shear at shear plane
(2) Kinetic co-efficient of friction.(7 marks) 2 (a) Discuss various types of tool wears and their causes.(7 marks)

Answer any two question from Q2 (b) or Q2 (c)

2 (b) A 300mm dia. bar is turned at 45rev/min with depth of cut of 2mm and feed of
0.3mm/rev. The forces measured at the cutting tool point are
Cutting force = 1850N Feed force = 450N
Calculate
(1) power consumption
(2) specific cutting energy.(7 marks) 2 (c) The following equation for tool life is given for a turning operation
V T^0.13 f^0.77 d^0.37=C
A 60 min tool life was obtained while cutting at V = 30m/min, f = 0.3mm/rev and d = 2.5mm.
Determine the changes in tool-life if the cutting speed, feed and depth of cut are increased by 20% individually and also taken together.(7 marks)

Answer any two question from Q3 (a), (b) or Q3 (c), (d)

3 (a) Classify various non-conventional machining processes.(7 marks) 3 (b) Explain the working principle of EDM. What are the main process parameters. State advantages of EDM.(7 marks) 3 (c) State various thread manufacturing methods.(3 marks) 3 (c) Explain gear finishing processes.(7 marks) 3 (d) Differentiate between gear forming and gear generating methods.(4 marks)

Answer any two question from Q4 (a), (b), (c) or Q4 (d), (e), (f)

4 (a) What are the advantages of using jigs and fixtures.(3 marks) 4 (b) Explain in brief Angle jig.(4 marks) 4 (c) Explain basic design steps for cam for single spindle automat.(7 marks) 4 (d) Explain in brief hydraulic clamp.(3 marks) 4 (e) Explain in brief Indexing jig by taking suitable example.(4 marks) 4 (f) Differentiate between Capstan and turret lathe(7 marks)

Answer any two question from Q5 (a), (b) or Q5 (c), (d)

5 (a) How cutting force is calculated for press work. What are the various methods for reducing force requirements.(7 marks) 5 (b) Explain in brief two pass layout in press work by taking suitable example.(7 marks) 5 (c) Explain various methods of mounting of punches.(7 marks) 5 (d) Explain various machine tool structures, based on rigidity.(7 marks)