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.
Maximum Radius =60mm
minimum radius =40mm
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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