Question Paper: Production Process 2 Question Paper - December 2012 - Mechanical Engineering (Semester 4) - Mumbai University (MU)
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## Production Process 2 - December 2012

### MU Mechanical Engineering (Semester 4)

Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

### Any four

1(i) Attempt any four of the following:
Explain 3-2-1 method of loation in case of jigs.
5 marks

1(ii) Explain the followin in conn ection with the measurement of surface roughness
Waviness
Ra-value
The lay
Sampling length
5 marks

1(iii) Define the following term w.r.t rolliing
Angle of contact
Forward slip
5 marks

1(iv) Distinguish between gear hobbing and gear shapping 5 marks

1(v) Steps in designing of bending dies. 5 marks

1(vi) Prove that Vc=V.rc 5 marks

2(A) Calculate & design a round pull type borach for machining hole of diameter 35 H7 & length 20 mm in a work-piece steel of carbon steel.Specific cutting Force=4200N/mm2,IT7=0.025mm;Tooth rise=0.03mm,Cutting speed designed values. 5 marks

2(B) Determine & design from tool graphically,to cut a semicircular groove in the cylindrical work piece whose detals are given below.
Assume rake and relief angles as 10° &6° respectively.
5 marks

3(A) Following data was recorded in orthogonal cutting operation m/c with tipped tool cutting speed =120m/min Feed=0.2mm/rev,depth of cut =2mm ,chip thickness =0.45mm Cutting Force =185kgs.feed force =75kgs,Rake angle=10°
Calculate the following:
Chip thickness ratio
Resultant force
Sher angle
Length of shear plane
Frictional force
Friction angle
Normal compressive force
Coefficient of friction
Shearforce
Shear velocity
5 marks

3(B) Discuss any two of the following:
Different types of rolling mills
Torque and power calculation in rolling
Types of jig bushes.
5 marks

4(A) Discuss the step of designing drill jig 5 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
Width if cutter:80mm
RPM of cutter:165
Table velocity:80mm/min
Size of job:150×60min
Find-
Maximum uncut chip thickness & length of uncut chip
Height of feed ridges
Maximum number of cutting edges cutting simultaneously
Minimum depth of cut to be employed with this cutter
Cutting time if over is 4% of job length.
5 marks

5(A) Design & sketch a blanking die for producing 40000 pieces.The part is round in shape having diameter is 50mm.The material is 2mm thick M.S sheet,Having shear strength 0f 430N/sq.mm & ultumate tensile strength 600N/sq.mm.Assume suitable data wherever necessary.Following factors are expected in the design of die-
Strip layout
Cutting clearance,
Cutting force
Approximate shut height
Size & position of dowels & Screws:
5 marks

5(B) Draw the necessary views of twist drill & mark all features on theses views.Explain the force analysis. 5 marks

6(A) a steel shaft 50mm diamter is required to be turned distance of 300mm on an engine lathe.Depth of cut 6mm & rate of feed 0.2 mm/rev.Two types of tool are available for this pirpose
(i)H.S.S (ii) Tungten Carbide.The following are the data available:

 Tool Material Tool Life(minutes) Cutting speed(meters/minute) Tool changing time (minutes) H.S.S 20 40 3 35 31 Tungsten Carbide 15 125 3 45 85

HSS costs an average of Rs 30 per edge & carbide costs Rs 75 per edge.Take the operating cost as Rs 120 per hour.analyze the selection of the tool material nased on minimum cost of machining 5 marks

6(B) Distiguish between
Compound and progressive die
Drilling and millimg fixture
5 marks

### Any four.

7(i) Write short on any four
Cutting fluid
5 marks

7(ii) Extrusion 5 marks

7(iii) Cutting tool materials 5 marks

7(iv) State the requirements of dynamometer any one mechanical dynamometer. 5 marks

7(v) ORS. 5 marks

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