A presentation on

Design & Development of Geneva Wheel Based Auto Roll Punching Machine

Department of Mechanical EngineeringGokhale Education Society’s

R. H. Sapat College of Engineering, Management Studies & Research, Nashik

Project Members:

Aashish D. Thakare.

Vinayak S. Supekar.

Ganesh S. Supekar.

V. Ghegadmal.

Under the guidance of

Prof. V. T. Mandlik

PROJECT TEAM

Introduction

Literature Survey

Project Execution

Project Action Plan

Major Components

Selection of Material

Design

Assembly Flowchart

Cost Estimation

Results & Discussions

CONTENT

Punching or pressing is the main or initial operation in sheet metal process sequence

The proposed work describes the design & fabrication of prototype of automatic punching machine

Geneva Drive is a mechanism which translates continuous rotary motion into intermittent rotary motion

Geneva Mechanism: simple in construction, accurate, self-locking function

Introduction

Sr. No. Title Researchers Key Points

01. Automatic Punching Machine: A Low Cost Approach

Arun S, SreeRajendra andVijayavithalBongale

• The proposed work describes the design and fabrication of prototype of auto. Punching machine

• By automating this process one can have a greater control over the process.

• This system can replace existing manual feed andoperated punching machine.

02. Optimization ofKinematic Characteristic of Geneva Mechanism by Genetic Algorithm

M. Heidari, M. Zahiri, and H. Zohoor

• paper discusses the use of variable input speed for optimization of kinematic characteristic of Geneva mechanism.

• The objective is lowering maximum acceleration and jerk of driven wheel.

Literature Review

Sr. No. Title Researchers Key Points

03. Dynamic Optimization of Geneva mechanism

Vivek A. Sujan, Marco A. Meggiolaro

• It presents design of Geneva wheel mechanism that performs better than conventional approach.

• Design goal is to minimize the maximum angular jerk of wheel

04. Design of Micromachined Geneva wheel to obtain intermittent motion

VaradarajanVidya, PalaniKumaresan

• The paper discusses design and fabrication of Geneva mechanism

• The system is simple to layout & can be fabricated using the standard process

Problem Identification:

In conventional Punching Machine, The job is to be marked

The sheet is to be aligned and fed manually for every punched hole

Lead time of system is more due to manual feedingThe safety of worker is at stakeRequires higher material handling time

Project Execution

Scope of Project

This is a low cost automationIt is economical as compared to hydraulics and

pneumatics Operation is smooth and requires less effortsOnce the job is fed it is punched with the help of

intermittent motion of Geneva Mechanism

Project Action PlanW

ee

ks

Major Components

Geneva Mechanism Wiper Motor

Chain Drive Punching Machine

Sheet Metal Pillow Block Bearing

Rubber Rollers Battery

Design

Procedure in Machine Design

General Steps followed are as follows:

Preparation of statement indicating the purpose of machine

Selection of Mechanism for desired motion

Calculation of forces and dimensions involved

Selection of material

Preparation of component drawing & manufacturing

Assembly of component

Testing machine for functioning

I. Geneva Mechanism

1] Centre Distance = C = b/cos(180/n) = 120/cos(180/4)

c = 170mm

2] a = drive crank radius = c2 – b2 =170 2 - 1202

a = 120mm

3] s = slot centre length = (a+b) – c = (120 + 120) – 170

S = 70mm

4] W = slot width = P + t = 10+7

W = 17 mm

5] y = stop arc radius = a - (P*1.5)

y = 105 mm

6] Z = stop disc radius = y – t =105 – 7

Z = 100 mm

7] V = Clearance arc = bz/a = (120*98)/120

V = 98 mm

II. Punching Force

Punching Force = p x t x ῑ

P.F = [π*4*1*0.65*65]/9806.5

P.F = 0.0541 tonne

III. Connecting rod length:

obliquity ratio= Length of C.R./Radius of disc

2 = l/100

l = 200 mm

P.F = [perimeter (mm) x thickness(mm) x shear strength (N/mm2) ]

9806.65 (N/tonne)

IV. Chain Calculations:

1] Motor powerP = (2πNT)/60 WattP = (2*3.14*65*12)/60P = 81.68 W = 0.081 kW

2] kW Rating Of Chain := [(kW to be transmitted) * Ks]/(K1 * K2)= (0.081 * 1.0) / 1.0 * 1.18 = 0.068 kW

Where,Ks = Service Factor; K1 = Multiple Strand FactorK2 = Tooth Correction Factor

3] Dimensions :Pitch = p = 9.525 mmRoller diameter = 6.35 mmWidth = w = 5.27 mmTransverse pitch = 10.24 mm

4] Pitch Circle Diameter Of Driving and Driven Pulleys

D1 = P/sin (180/Z1)= 9.525/ sin (180/20)

D1 = 60.88mm

For Driven Sprocket,Z1 = Z2 = 20D2 = P /sin (180/Z2) = 9.525/sin (180/20)D2 = 60.88 mmWhere,D1 = Diameter of Driving Sprocket; D2 = Diameter of Driven SprocketZ1 = No. of Teeth on Driving Sprocket; Z2= No. of Teeth on Driven Sprocket

5] Number Of Chain Links :Range (30 p to 50 p) a = 45 p

= 45 * 9.525 = 428.62 mm

6] Ln = no of links

= 2 (a/p) + ((Z1 + Z2)/2) + [((Z1 – Z2)/2)] * (p/a)

= 2 (450/9.525) + (20 + 20/2) + 0

Ln = 115

7] Correct Centre Distance

= [Ln – ((Z1 + Z2)/2)]

= [115 – ((20+20)/2)] = 95 mm

a = P/4{[Ln – ((Z1 + Z2)/2)] + [(Ln – (Z1+Z2)/2)2 – 8((Z1-Z2)/2π)2]}

a = 9.525/4 [95+(952 – 8*0)0.5]

a = 452.43 mm

8] To provide small sag, centre distance is given by

a = 0.998 * actual centre Distance

= 0.998 * 452.43

a = 451.52 mm

Assembly Flowchart

Fabrication of standMounting of Geneva

mechanismMounting Wiper

Motor

Engagement of Geneva Drive with

Roller by Chain Drive

Attachment of Connecting Rod

Rubber Roller Attachment

3D Concept Drawing in Unigraphics

Actual Prototype

Cost of Material

Total Cost of Material = Rs.750/-

Cost of machining :

Total cost of machining = Rs.1140/-

Cost Estimation

Cost of Standard Part :

Total Cost of Standard Part = Rs.7450/-

Cost of Transportation + Other Charges = Rs.1500/-

Total Cost = [Cost of (Material + Machining + Standard Parts) +VAT]

= Rs.10840 + VAT (12.5%)

= 10840 + 1335

= Rs.12,195 /-

Sr. No. Job No. Time (Sec) Number of Punches

Manual

Punching

Machine

Actual

Prototype

1. 01 60 20 54

2. 02 60 21 53

Result and Discussion

Testing Results:

Operation Time:Average time for 10 punches is 30 sec.

For Auto roll punching machine,

Average time for 10 punches is 17 sec.

Operation time reduction in % = [(30-17)/30]*100

= 0.43 * 100

= 43%

Therefore, reduction in operation time = 43%

Advantages:

Compared to pneumatics, it is economical.

No need of expertise to operate the machine.

Operation is done in a flow, so we can obtainmore output with less effort.

This machine is simple in construction andcompact in size.

Easy to assemble and disassemble.

Low initial cost and maintenance cost.

Applications:

Machine is very useful in making series of identicalholes with same diameter and same pitch.

The machine can be used in applications whereequidistant punched holes are required.

If the shape of punch is changed it can give variety inpunched shape as per requirement.

Conclusion:

Operation time reduced from 30 seconds to 17second for every 10 punches.

43% reduction in Operation time.

Machine ensures operator’s safety.

The energy required for the machine is also less.

The machine gives equidistant punched holes withalignment.

Future Scope:

If the electronic sensors are used to turn off the machineas soon as the operation is over, we can reduced manualoperation as well as energy.

If the slots in the Geneva wheel are increased, the numberof punched holes can also be increased without anyadditional efforts.

Reference

[1] Design of a Micromachined Geneva Wheel as a mechanism to obtain intermittent motion from a constantly rotating source Varadarajan Vidya Palani Kumaresan University of California, Berkeley

[2] Wilson tool international journal 12912 farnaham avenue, February 2013, MN 5511 –800-328-9646

[3] Design data book ISBN 978-81-927355-0-4, kalaikathirachchgam, coimbatore. Page No.1.30

[4] Design of machine elements ISBN 978-00-706114-12, v. b. bhandari, Page no. 545-560

[5] Materials Handbook, Fifteenth Edition, 2008, Mc-Graw-Hill Handbooks, George S. Brady, Henry R. Clauser

Bibliography:[6] https://newgottaland.com/2012/08/01/08/make-geneva-wheels-of-any-sizes/[7]www.directindustry.com/industrial-manufacturer/manual-punching-machine-146110.html/[8] www.penandpaper.co.in/p/2827/kangaro-metal-punching-machine-dp-520/[9] www.autozone.com/electrical-and-lighting/wiper-motor/[10]www.bikesindia.org/reviews/drive-chains-o-ring-x-ring-vs-non-standard-chains.html/[11]www.thelibraryofmanufacturing.com/sheetmetal_basics.html/[12] www.bearingtips.com/pillow-block-bearing/[13]www.batteryuniversity.com/learn/article/lead_acid_battery_in_moderntimes[14] www.kdjoshi.com/rubber-roller.html/