cad final project ppt
TRANSCRIPT
-
8/8/2019 CAD Final Project Ppt
1/35
By:
Sidhant Sharma Date: 12/15/2010
-
8/8/2019 CAD Final Project Ppt
2/35
-
8/8/2019 CAD Final Project Ppt
3/35
Introduction
Automation
Basic termin0logies
-
8/8/2019 CAD Final Project Ppt
4/35
AutomationAutomation is the use of control systems and information
technologies to reduce the need for human work in industry
Mechanization on the other hand is the aid of machinery toassist humans with the muscular requirements of work
Need for Automationy Higher production rates
y
Increase in accu
racyy Replacing human operators in hard physical, monotonous or dangerous
work
y Performing tasks beyond human capabilities of size, weight, speed,endurance, etc.
y Economy improvement
-
8/8/2019 CAD Final Project Ppt
5/35
-
8/8/2019 CAD Final Project Ppt
6/35
Basic terminologies Welding A fabrication process that joins materials,
usually metals or thermoplastics, by causing
coalescence. Eg. gas welding, resistance welding,
friction welding, laserbeam welding, etc.
FixtureA device which locates and secures a
workpiece during a machining operation
Features of a fixture -
y Location systemy Clamping system
y Control system
y Foolproofing and asymmetry
y Weight and Handling
-
8/8/2019 CAD Final Project Ppt
7/35
Product and systemdescription
-
8/8/2019 CAD Final Project Ppt
8/35
Product and System descriptionA Safe (also called strongbox) is a secure lockable box used for
securing valuable objects against theft or damage
Two models of DefenderPlus Safes from Godrej & Boyce Mfg.
Co. Ltd. are shown below
61 (height) model
26 model
-
8/8/2019 CAD Final Project Ppt
9/35
Product and System description contd.. The 61 model is composed of three subassemblies
1. Inner body
2. Door
3. Outer body - Fixture is being designed for making this
subassembly (shown in next slide)
1. Inner body being inserted 2. Door assembly
-
8/8/2019 CAD Final Project Ppt
10/35
Problem description
-
8/8/2019 CAD Final Project Ppt
11/35
Problem description : To design a pneumatic
welding fixture for outer body subassembly
3. Outer body subassembly and operations
Leftshell
Rightshell
Lug
-
8/8/2019 CAD Final Project Ppt
12/35
Why is the problem worth study??
y Design : Designing a fixture involves designing all of itselements i.e location, clamping, control systems
y Motion Study: Motion study is a necessity as the fixtureinvolves moving elements that must move precisely so as
to maintain tolerances
y Optimization: The problem breaks down into a multi-optimization problem as we optimize the assemblysequence, process sequence, setup-time, etc.
y FEA : We analyze the clamping forces and their effects on
the parts as a preventive measure
-
8/8/2019 CAD Final Project Ppt
13/35
Design goalsy To design the location system
y To design pneumatic clamps for the clamping system
y To carry out mechanical simulation on the fixture, which
will help in fixing the location, design and geometry ofclamps
y To optimize the setup time on the fixture
y To optimize the sequence of assembly of the outer body
y To design the control electro-pneumatic circuit for the
finalized motion sequence
-
8/8/2019 CAD Final Project Ppt
14/35
Survey of pneumatic
clamping mechanisms
-
8/8/2019 CAD Final Project Ppt
15/35
Pneumatic Clamping Mechanisms
-
8/8/2019 CAD Final Project Ppt
16/35
Alternative fixture designs
-
8/8/2019 CAD Final Project Ppt
17/35
Design 1
Design 2
-
8/8/2019 CAD Final Project Ppt
18/35
Decision making : Final Design
Weightage to factors out of 1
Sr no Factors Design 1 Design 2 Selection
1 Pneumatic elements no. 0 1Design 2
2 Weight of fixture 0 1 Design 2
3 Workpiece securing 1 0Design 1
4
Ease of welding
operation 0 1
Design 2
5 Setup time 0 1Design 2
6
Spacing for pneumatic
wiring 0 1Design 2
7 Sequence control0 1 Design 2
8 Design of circuit 1 1 Design 1,2
-
8/8/2019 CAD Final Project Ppt
19/35
CADModels
-
8/8/2019 CAD Final Project Ppt
20/35
Horizontal toggle clamp
cad final project simulationvideos\horizontal pneumatictoggle clamp mechanism.avi
-
8/8/2019 CAD Final Project Ppt
21/35
Hold down clamp
cad final project simulationvideos\vertical pneumatic
toggle clamp mechanismsimulation.avi
-
8/8/2019 CAD Final Project Ppt
22/35
Final fixture assembly
-
8/8/2019 CAD Final Project Ppt
23/35
-
8/8/2019 CAD Final Project Ppt
24/35
Geometric Analysis
Lug location system
Right shell location
-
8/8/2019 CAD Final Project Ppt
25/35
Motion analysis
It can be observed that 24 mm of the piston stroke is converted into 11 mm ofthe clamping rod movement through the toggle mechanism. Thus we can fix
the clamping bar 8-10 mm away from the su
rface to be clamped.
Piston rod displacement Clamping rod displacement
-
8/8/2019 CAD Final Project Ppt
26/35
Motion analysis contd..
For 24 mm of the piston stroke the clamping point moves 55mm horizontally and 88 mm vertically. Thus we placed it 40mm horizontally and 20 mm below the point to be clamped.
iston rod displacement lamping rod path trace
-
8/8/2019 CAD Final Project Ppt
27/35
Setup time analysis resultsSet
ti e(sec)
r cess
ti e(sec)
Trial sequence 64 5
Trial sequence 47 98
Difference 17 17
cad final project simulationvideos\fixture trial2.avi
fixture mechsimulation setup timeanalysis.xlsx
-
8/8/2019 CAD Final Project Ppt
28/35
Clamping force and stress analysis
Horizontal clamp force
Lug clamp force Lug
Left shell
-
8/8/2019 CAD Final Project Ppt
29/35
Clamping force and stress analysis contd..
Old design of
lug clampingrod
New design withreduced stress
by approx. 50 %
-
8/8/2019 CAD Final Project Ppt
30/35
Electro pneumatic system equivalent
Fixture mechanical system
-
8/8/2019 CAD Final Project Ppt
31/35
Electro pneumatic control circuit
cad final project simulationvideos\IMG_0132.MOV
-
8/8/2019 CAD Final Project Ppt
32/35
ChallengesThe main problems faced in the project were-
y Setting up the event based motion sequence inSolidworks as there was no provision for event based
motion simu
lation in the premiu
m versiony High computation times as the simulation was upto 1
minute in certain cases
Solution: The event based problem was solved by theuse of independent linear motors to control the motionof each pneumatic clamp independently in the requiredsequence
-
8/8/2019 CAD Final Project Ppt
33/35
Website demo
https://sites.google.com/site/sidhantsharmacadapplications/
-
8/8/2019 CAD Final Project Ppt
34/35
ReferencesBOOKS
[1] Jigs and Fixture Design by Edward Hoffman
[2] Design of Jigs and Fixtures by Joshi
WEBSITES
[1] www.wikipedia.com[2] www.youtube.com
[3] http://www.drillspot.comp
-
8/8/2019 CAD Final Project Ppt
35/35
Questions??