This presentation contains die and punch design.

1. By Alemu A. & Alebachew G. 1
Welcome to
The Final Year Project Presentation on:
Design, Improvement
and
Manufacturing of Die and Punch Honey Queen
Bee Excluder
Adviser Mulu Byraye (Ph .D)

2. By Alemu A. & Alebachew G. 2
Topics to be covered
Objective
Introduction
Main component of die assembly
Design analysis
Cutting force reduction
Design of spring
Design of punch
Die block design
Design of guiding mechanism
Design of pin and bush
Design of bolt for fasten punch plate and punch holder
Method of manufacturing
Limitation
Conclusion
Recommendation

3. By Alemu A. & Alebachew G. 3
Objective
The objective of this project is:
 To removes problem that face in bee harvesting
 To reduce costs that spent for excluder
 Simplifying the queen bee excluder die design
 To manufacture single die and punch in Mekelle
University workshop

4. By Alemu A. & Alebachew G. 4
Introduction
 Queen bee excluder is vital for bee harvesting
so that to bring in application it needs proper
design
 Queen bee excluder hole is very small and
needs high precision to manufacture.
 It involves in the application of dies and punch
 In die there are many application like blanking,
lancing, shaving, notching, piercing etc. but
piercing is only considered here.

5. By Alemu A. & Alebachew G. 5
To design queen bee excluder die & punch the
following terms are expected to be known
 Press tonnage (capacity)
 Stork length
 Die area (space)

6. By Alemu A. & Alebachew G. 6
Main Component of die assembly
 Punch
 Punch holder
 Die
 Stripper
 Stripper spring
 Die shoe
 Bolts
 Stripper Plate

7. By Alemu A. & Alebachew G. 7

8. By Alemu A. & Alebachew G. 8
Design analysis
• Cutting force calculation_ it helps in selection of
proper press tonnage.
• The formula to determine cutting force is based
on:
Thickness of the stock material
Perimeter of the cutting edge
Shear strength of the stock material
Cutting force, F=SPT
The material selected is Al with T=0.8mm,
S=7.5 tonn/in2

9. By Alemu A. & Alebachew G. 9
Cont…
• the length of a single hole selected is 189mm by
4mm due to the following advantages. These
are:
 Reducing manufacturing cost
Simplifying method of manufacturing
Increasing accuracy
Providing sufficient area for the
movement of bee.

10. By Alemu A. & Alebachew G. 10
Cont…
• Amount of force for a single hole
• Fsh = SPT=3.5 ton
• Force in a single row
• Fsr = 2xFsh = 7 ton. Because # of holes are two
• Force for a quarter part of the work piece
• Fq= Fsh x Nc /2 x Nrs /2 = 52.5 ton.
Where, Nc = # of holes in a single column=30
Nrs = # of holes in a single row = 2
• Force required for half part of the work piece
• Fhf = Fsh x Nc /2 x Nrs =105 ton.
• Force required for a full part of work piece
• Ff = Fsh x Nc x Nrs =210 ton.

11. By Alemu A. & Alebachew G. 11
Cutting force reduction
 To reduce the cutting force it is better to use :
Stepped punch
Double shear punch
 Reduction of force due to shear angle is:
• F* = K x F
• K = T x ρ/S where ρ is percentage of penetration.
• Force reduced by full shear can also approximated by 30%.
 Force reduced in a single hole
• Reduced force by stepped punch in a single hole is zero
• Reduction of force due to double shear is:
» F*sh = Fsh – K x Fsh =2.4 ton.
 Force reduced in a single row is:
• Force reduced by stepped punch is zero.
• Reduction of force due to double shear
» F*
sr = Fsr – K x Fsr =4.9 ton.

12. By Alemu A. & Alebachew G. 12
Cont…

13. By Alemu A. & Alebachew G. 13
Cont…
 Force reduced in quarter part is:
• Reduction of force due to stepped punch is half of the normal punch.
» F*Q1 = Fq / 2 = 26.2 ton.
• Reduction of force due to double shear
» F*
q = F*
q1 – K x F*
q =18.4 ton.
 Reduction of force for half part
• Reduction of force due to stepped punch
– F*
hf1 = Fhf /2 = 52.5 ton.
• Reduction of force due to double shear is
– F*
hf= F*
hf1 – K x F*
hf1 = 36.75 ton.
 Reduction of force for full part
• Reduction of force due to stepped punch
– F*
f1= Ff / 2 = 105 ton.
• Reduction of force due to double shear is
– F*
f=F*
f1 – k x f*
f1=73.5 ton

14. By Alemu A. & Alebachew G. 14
cont…
In this design the full part of the punch
holder and the die are designed in to four
pieces and then assembled as one part .
This is to reduce manufacturing cost, easy
to maintain and simplifies its
manufacturing method.
In a piece of die there are 15 # of holes.

15. By Alemu A. & Alebachew G. 15
 Springs are used in order to return back the punch to its original place.
 The type of material selected is steel which is quenched and tempered
 factors to be considered are:
– stripping force
– space available for spring mounting
– permissible deflection
 Assumptions -it is helical spring
-spring index, c=3
- diameter of the spring coil, D=18 mm
S = 7.5 tonn / in2 = 103 Mpa
w = f / N = 93420 / 20 = 4671N
 By using the following relation the spring is checked for shear stress.
=
Design of spring



 

 

2
8
d
WC



M p a
9 9 1


That means, 991Mpa < 1061.5 Mpa, So it is safe condition
M p a
x
u lt 5
.
1 0 6 1
1 9 3 0
5 5
.
0
5 5
.
0 

 


16. By Alemu A. & Alebachew G. 16
Punch design
• The material selected for the punch is high strength low alloy steel (ASTM A
242)
• Length assumed is 50mm and it is checked for crushing and buckling using
the relation. The total weight wiil be ,
• Wt=Wp+Wph+Wpress = 260+432+654x103=655Kg
= 14.2Mpa
• Buckling of the punch is checked by using σ =π2xE/(L/r)2 =407.9Mpa from this
buckling length=80mm but 50 mm taken for the design to be in safe condition
• In this design the process is piercing, the cut out part is the waste and the
remaining part is the work piece as a result the punch and the die hole are
made with some clearance in either side.
A
Fsp /



 S X
F
u l .

28.4Mpa < 480Mpa which is safe condition

17. By Alemu A. & Alebachew G. 17
Cont…
Clearance between die and punch
 Clearance is the intensional space between the
punch cutting edge and the die cutting edge.
 Since the workpiece material is Alumnum,
c=6%,C=cT=6x0.8=0.05
 punch size =Lc1 -2c where Lc1 is die size.
 Angular Clearance in between is ½0 to 20 on
either side depending on the material and the
shape of the work piece

18. By Alemu A. & Alebachew G. 18
Die block design
• Factors that influence design of die block are:
– Part size
– Part thickness
– Type of die
• The thickness of the die taken is 40mm.Selection is based on
this table with relation to stripper
Srtipper thickness(in) die block height(in)
0 to 1/16 15/16
1/16 to 1/8 11/8
1/8 to 3/16 13/8
3/16 to 1/4 11/8
over 1/4
• It is manufactured by milling machine.
• Material used is high strength low alloy steel.

19. By Alemu A. & Alebachew G. 19
Design of guiding Mechanism
Guiding mechanism is used to keep the alignment of the punch to the die
Here pin and bush are selected and proper clearance is determined by:
DBp =Dp +Cp , Cp =clearance between the bush and the pin & DBp =diameter of bush
DBp=30mm+ 2x 0.05 mm =30.1mm
Design of bolts used for fasten punch plate with punch holder
The material selected for this bolt is high strength alloy steel with ASTM(A242)
 Weight on a single bolt Wsb =655/16 =41KN
Since this bolts are exposed to tensile force it is checked for its safety as:.
 The length of the bolt already selected is M12 with length of 25mm
It is safe
Mpa
Mpa
ul 400
103 

 

Mpa
x
KN
sXA
F
Ws 103
113
3
/
41
.
/ 



Assembly Drawing

20. By Alemu A. & Alebachew G. 20
Method of manufacturing
 The die & punch are manufactured by using milling machines.
 But the punch has concave cutting edge and this edge is done on milling machine by
using concave cutters.
 Grinding is also used for surface finish.
Attemtes done to manufacture the prototype
 First the design analysis was analysed in order to determine dimensions and to
check safe conditions.
 Then using milling machine we tried to produce the prototype in industrial
engineering department workshop.
 The material used in our trial was rolled mild steel which is available in the work
shop
 But, there was challenges due to some limitations as a result the prototype is not
produced
Problems/Limitations are:
– Smaller milling machines are unable to change the rolled steel in to rectangular
shape.
– The heavy duity millings are not working because they need maintenance.
– The required 4 and 4.1 mm cutters are not available in the workshop.

21. By Alemu A. & Alebachew G. 21
Conclusion
 This project focuses on the problems that face in bee
harvesting.This problem is removed by using the excluder.
 The method of manufacturing for the excluder is simplified by
using proper method of design.
 In this design,it is possible to produce one Aluminum sheet
excluder with the required size in a single press.
 But before now some companies produce it by piercing one
hole at a press
 In general this design reduces manufacturing cost, lobor,time
and maintenance cost.
 But this method is more appropriate to produce the excluder.
The only challenge is to produce the die & punch.
 The number of holes produced in one press is 60.

22. By Alemu A. & Alebachew G. 22
Recommendation
 Die and punch manufacturing needs high precision, so it needs involvement
of skilled persons.
 Since it needs precise manufacturing, greater care should be there.
 The work piece material is aluminum which can form a sharpened edge on
the time of piercing and this cause damage on the bee body ,so proper
design and polishing is required.
 The die and punch should construct from strong material.
 This university should full fill the necessary machines and tools to
manufacture so that it can solve the problem.

23. By Alemu A. & Alebachew G. 23

24. By Alemu A. & Alebachew G. 24