Pneumatics – Concepts Design and Applications

اسم المؤلف

Jagadeesha T

التاريخ

تاريخ النشر24 ديسمبر 2021

التصنيف

فيهندسة الإنتاج والتصميم الميكانيكىهندسة السياراتهندسة القوى الميكانيكية

المشاهدات

665

التقييم

التحميل

Pneumatics – Concepts Design and Applications
Jagadeesha T
Assistant Professor
Department of Mechanical and Production Engineering
National Institute of Technology Calicut
Kozhikode, Kerala
CONTENTS
Preface
Acknowledgements

INTRODUCTION TO PNEUMATICS
1.1 Pneumatics and Its Meaning
1.2 History of Pneumatics
1.3 Pneumatic Systems
1.4 Choice of Working Medium
1.5 Advantages of Pneumatics over Hydraulics
1.5.1 Differences between hydraulic and pneumatic systems
1.6 Characteristics of Pneumatic Systems
1.7 Applications of Pneumatics
1.8 Properties of Air
1.8.1 Composition
1.8.2 Free air and standard air
1.8.3 Atmospheric pressure, gauge pressure and absolute pressure
1.8.4 Variation of pressure with altitude
1.8.5 Pressure ranges
1.9 Gas Laws
1.9.1 Boyle’s law
1.9.2 Charles’ law
1.9.3 Gay-Lussac’s law
1.9.4 General gas equation
1.10 Basic Components of Pneumatic Systems
1.11 Comparison of Hydraulic and Pneumatic Systems
1.12 Comparison of Different Power Systems
1.12.1 Electrical power transmission
1.12.2 Mechanical power transmission
1.12.3 Hydraulic power transmission
1.12.4 Pneumatic power transmission
Summary
Exercises
PREPARATION OF COMPRESSED AIR
2.1 Air Preparation
2.2 Classification of Air Compressors
27
28viii Contents Contents ix
115
4.7.2 Horizontal cylinder
4.7.3 Inclined cylinder
4.8 Rotary Actuators
4.8.1 Vane type actuators
4.8.2 Rack and pinion rotary actuator
4.8.3 Helix spine rotary actuator
4.9 Air Motors
4.9.1 Vane motor
4.9.2 Piston motor
4.9.3 Diaphragm air motor
4.9.4 Turbine motor
4.9.5 Gear motor
2.2.1 Reciprocating compressors
2.2.2 Rotary compressors
2.2.3 Dynamic displacement compressors (turbo compressors)
2.3 Comparison of Different Compressors
2.4 Control of Compressors
2.5 Selection and Specification of Compressors
2.6 Importance of Secondary Treatment
2.7 Aftercooler
2.7.1 Functions of compressed air aftercoolers
2.7.2 Types of aftercoolers
2.8 Drying of Compressed Air
2.8.1 Types of air dryers
2.8.2 Theory of drying
2.9 Storage of Compressed Air
2.9.1 Air receivers
2.9.2 Sizing of air receivers
Summary
Exercises
PNEUMATIC CONTROL VALVES
5.1 Valves
5.2 Direction Control Valves
5.2.1 Types of direction control valves
5.2.2 Non-return valves
5.2.3 Flow control valves
5.2.4 Pressure control valves
5.3 Valve Specification
5.4 Valve Sizing
5.4.1 Valve sizing of flow control valves
5.4.2 Sizing of direction control valves
Summary 134
Exercises 56 55 135
CONDITIONING AND DISTRIBUTION OF COMPRESSED AIR
3.1 Fluid Conditioners
3.1.1 Air filters
3.1.2 Air regulator
3.1.3 Air lubricator
3.1.4 Filter-regulator-lubricator (FRL) unit
3.2 Air Distribution System
3.3 Guidelines for Component Selection
3.4 Guidelines for Compressor Sizing
Summary
Exercises
PNEUMATICS ACTUATORS AND AIR MOTORS
4.1 Pneumatic Actuators
4.2 Types of Pneumatic Actuators
4.2.1 Types of pneumatic cylinders (Linear actuators)
4.3 Standard Metric Cylinders
4.3.1 Graphic symbols for cylinders
4.4 Cylinder Mountings
4.5 Cylinder Force, Velocity and Power
4.6 Acceleration and Deceleration of Cylinder Loads
4.7 Linear Motion Using Pneumatic Cylinders
4.7.1 Vertical cylinder
Summary 177
Exercises
SINGLE ACTUATOR CIRCUITS
6.1 Pneumatic Circuits and Pneumatic Circuit Diagrams
6.2 Single Acting Cylinder Control
6.2.1 Direct control of a single acting cylinder
6.2.2 Indirect control of single acting cylinder
6.2.3 Control of a single acting cylinder using an “OR” valve
6.2.4 Control of single acting cylinder using an “AND” valve
6.2.5 Control of a single acting cylinder using a “NOT” valve
6.3 Direct Control of a Double Acting Cylinder
6.3.1 Indirect control of double acting cylinder using a memory valve
6.4 Supply and Exhaust Air Throttling
6.4.1 Supply air throttling
6.4.2 Exhaust air throttling
6.5 Methods of Checking the End Position of a Cylinder
114x Contents Contents xi
6.5.1 Use of limit switches
6.6 Pressure Dependent Controls
6.7 Time-Dependent Controls
Summary
Exercises
ELECTRO-PNEUMATIC CONTROL
9.1 Introduction
9.2 Control Electrical Devices
9.2.5 Relays
9.2.6 Time delay relays (Timers)
9.2.7 Temperature switch
9.2.8 Reed proximity switches
9.2.9 Electronic sensors
9.2.10 Electric counters
9.3 Electro-pneumatics Circuits for Single Actuators
9.3.1 Direct control of single acting cylinder
9.3.2 Indirect control of a single acting cylinder
9.3.3 Direct control of a double acting cylinder
9.3.4 Indirect control of a double acting cylinder (5/2 valve, single
solenoid)
9.3.5 Indirect control of a double acting cylinder (5/2 valve, double
solenoid)
9.3.6 Control of a double acting cylinder, OR logic (Parallel circuit)
9.3.7 Control of a double acting cylinder, AND logic
9.3.8 Latching circuits
9.3.9 Double acting cylinder with automatic return (Spring return)
9.3.10 Direct control of a double acting cylinder with automatic return
(double solenoid)
9.3.11 Indirect control of a double acting cylinder with automatic return
(double solenoid)
9.3.12 Automatic return of a double acting cylinder
(using proximity switch)
9.3.13 Oscillating motion of a double acting cylinder (Forward)
9.3.14 Oscillating motion of a double acting cylinder (Return)
9.3.15 Control systems with timed response
9.3.16 Control of a double acting cylinder using an electric counter
with two end sensors
9.3.17 Oscillation of a double acting cylinder using proximity switches 383
9.3.18 Control of a double acting cylinder using a pressure switch
9.3.19 Control of a double acting cylinder using a delay on and off
timer and counter
9.3.20 Control of a double acting cylinder using a reed switch for
initial sensing
9.4 Electro-pneumatic Circuits for Multi Actuators
9.4.1 Two-group electro-pneumatic circuits
210 Push button switches 352
Limit switches
Pressure switches
Solenoids
MULTI ACTUATOR CIRCUITS- PART I
356
7.1 Single Actuator vs Multi Actuator Circuits
7.2 Classic or Intuitive Method
7.2.1 Coordinated and sequential motion control
7.2.2 Demonstration of the classic method
7.2.3 Elimination of signal conflict
7.3 Cascade Method
7.3.1 Demonstration of the cascade method
7.4 Step Counter Method
Summary
Exercises
MULTI ACTUATOR CIRCUITS- PART II
8.1 Pneumatic Logic Control
8.2 Signal Processing Logic Gates
8.2.1 OR Gate
8.2.2 AND Gate
8.2.3 NOT (Inverter) Gate
8.2.4 NANDGate
8.2.5 NOR Gate
8.2.6 XOR Gate (Exclusive OR)
8.2.7 XNOR (Exclusive NOR) Gate
8.2.8 NAND and NOR Universality
8.3 Boolean Algebra
8.3.1 Boolean algebra equalities or identities
8.3.2 DeMorgan’s Theorem
8.3.3 Sum of Products (SOP)
8.3.4 Product of Sums (POS)
8.3.5 Analysis Using SOP and POS and Truth Table
8.4 General Analysis of Karnaugh-Veitch Maps
8.4.1 Condition of Adjacency
8.4.2 Logic Circuit Design with Karnaugh-Veitch Mapping Method
8.5 Compound Circuit Design
8.6 Combinational Circuit Design
Summary
391xii Contents Contents xiii
12.3 Comparison of Hydropneumatic, Hydraulic and Pneumatic Circuits
Summary
Exercises
9.4.2 Design of three group electro-pneumatic circuits 400 482
Summary . 483
Exercises
MAINTENANCE AND TROUBLESHOOTING OF
PNEUMATIC SYSTEMS
PNEUMATIC CIRCUIT DESIGN USING PLCs
10.1 Introduction
10.2 Features of Programmable Logic Controllers
10.3 Hardwired Control System
10.4 PLC Systems
10.5 Major Components of PLC
10.6 Programming of PLC
10.7 PLC Timers
10.8 PLC Counters
10.9 PLC Memory Elements
10.10 Logic Design and PLC Circuits
10.11 Areas of Application of a PLC
10.12 PLC Standards
Summary
Exercises
423
424 13.1 Maintenance of Pneumatic Systems 485
13.2 General Maintenance Procedure
13.3 General Maintenance Guide
13.4 General Troubleshooting Guide
13.5 General Troubleshooting Procedure
Summary
Exercises
Index 511
INTRODUCTION TO FLUIDICS
11.1 Fluidics Defined
11.2 Historical Background
11.3 Advantages and Disadvantages of Fluidics
11.4 Coanda or Wall Attachment Effect
11.5 Basic Fluidic Devices
11.6 Schmitt Trigger
11.7 Turbulence Amplifier
11.8 Fluid Sensors
11.8.1 Types of fluid sensors
11.9 Application Examples
11.9.1 Control of a double acting cylinder
11.9.2 Control of two double acting cylinders in sequence
11.9.3 Continuous automatic reciprocation of a hydraulic cylinder
Index
Fill in the blanks
schedules
True or false
dust 5. packing
failure 3. filter element
absolute pressure 8, 9
absorption dryer 41-42
aftercooler 28, 40
air compressor 17, 28
air consumption 83, 466
air consumption rate 71, 73
air dryer 41
air filter 17, 62
air flow 30, 466
air leakage 83
air motors 3, 93, 123
air preparation 27
air receiver 7, 28, 50
air regulator 64
AND function 186, 303
AND functionality 193
arc suppression 457
atmospheric air 8
atmospheric pressure 8
automatic drain 63, 79, 80
component selection 82
compound circuit design 338
compressed air 1-3, 5
compressor sizing 83
compressors 2, 8, 17, 487
contacts 19, 360, 405
contaminants 28, 62, 365
control devices 427
control energy, 134
control of compressors 38
control of single acting cylinder 186
control valves 134
corrective maintenance 485
counters 352
cushioning 109, 190
cylinder 8, 18, 20-21, 108, 356, 371, 468
cylinder action 101
cylinder design 101
cylinder force 111
cylinder mountings 110
cylinder power 111
cylinder symbols 109
cylinder velocity 111
True 2. True 3. False 4. True 5. False
bar 8
bit 426, 429
bit logic operation 428
bolt mounting 147
Boyle’s law 11, 13
breakdown 508
detector 365
dew point 41
dew point temperature 48
diaphragm air motor 127
diaphragm compressor 33
diaphragm cylinder 95
diffuse sensors 367
direct control of double acting cylinder 187
direct control of single acting cylinder 182
direction control valves 135
displacement – step diagram 220
displacement-time diagram 220
dominant OFF circuit 374
cable cylinder 102
capacitive sensors 364
cascade method 234, 396
centrifugal forces 35
Charles’ law 13
check valve 158, 190, 475
circuit design 321
circuit design method 218
classic method 219
comparison of compressors 38
Index Index 513
hydraulic power transmission 20 multi-position cylinder 106
hydraulic circuit 482
hydraulic cylinder 470
hydraulic systems 4, 19
hydraulic motors 3
hydraulics 2, 4, 21
hydropneumatic circuit 482
hydropneumatics 474
idle return rollers 231
impact cylinder 105
inductive sensor 362
inertia force 115
intake system 28, 485
ISO 1219 109, 136, 155
isothermal process 30
kinetic energy 105
ladder diagram 427-428
laybyrinth compressor 33
limit switch 2, 191, 354-355, 468
linear actuator 21, 93, 120
linear motion 20, 114
loading forces 36
logic control 292
lubricator 2, 28, 62, 66, 487, 492
pressure gauge 50
pressure regulation 64
pressure sequence valve 164-165, 199
pressure switch 17, 19, 31, 50, 352, 355
preventive maintenance 485-486, 490
programmable logic controllers (PLC) 351, 423
programming of PLC 427
proximity sensor 352, 363, 465
push button 19, 195
push button switches 352
dominant ON circuit 375
double acting cylinder 93, 98-99, 189
down counter 367, 433
dryers 2, 28
duty cycle 39
dynamic displacement compressors 37
electric counters 367
electrical power transmission 19
emergency stop module 274
emitter 365
energy 4, 5
exhaust air throttling 189
expansion of air 48
filter-regulator-lubricator (FRL)
unit 67
filters 2, 28
fittings 69, 72
flanges 76
flow control valves 135, 160, 188
flow rate 17, 73, 122, 168-169,
fluid control valves 163
fluid power 1-2, 9, 455-456, 465
fluidic logic circuit 468
fluidics 455
force 2, 4, 6, 18, 456
force of gravity 97
free air 8
free air delivery (FAD) 30
frictional force 115
NC contact 353, 396, 399, 428
NO contact 353, 376, 396, 398, 428-429
non-return valves 135, 158, 160
non-venting type pressure regulator 66
normal air 8
normally closed (NC) 353
normally open (NO) 353
off-delay timer 201, 359
on-delay timer 201, 359, 381
one-way flow control valve 190, 205, 215
optical proximity sensor 365
OR control 185
OR functionality 185, 195
output module 427
quick exhaust valve 158, 161
radial piston motor 126
receiver 31, 50, 366, 488
receiver size 51
receiver tank 5, 51
reciprocating air compressor 31
reciprocating compressor 28
reed switch 107, 360, 393
refrigerated air dryer 43
regulators, 2
relative humidity 8, 46
relay logic 292
relays 19, 352, 358, 424, 426
reservoir 5-6, 17, 21
reset coil 367
reset coil, PLC 433
restraining force 200
ring layout 78
ring main 69, 78
rod-less cylinder 93, 102
roller valve 231
rotary actuator 21, 93, 120
rotary compressor 34
rung 392, 428
photoelectric detector 107
piston compressor 10, 28
piston motor 126
piston seals 99
PLC coil 428
PLC counters 432
PLC timers 431
PLCs 424, 426
pneumatic actuator 17, 21, 92
pneumatic circuit 8, 181, 482
pneumatic cylinders, 21, 93
pneumatic feed units 474
pneumatic power transmission 20
pneumatic systems 4, 19
pneumatic syterns 19
pneumatic valves 21
pneumatics 1-2, 6
positional layout 220
power 3, 5, 18, 52
power flow 428
preparation of compressed air 27
presssure gauges 487
pressure control valves 135, 164, 199
pressure dew point 48
pressure energy 37
maintenance 123, 166, 426, 449, 485,
487, 508
malfunction 360
malfunction in pneumatic systems 490
manifold layout 77
manifold mounting 136
mechanical power transmission 20
medium force 21
membrane dryer 41, 44
memory box 434
memory function 153, 211, 381, 433
meter-out circuit 190
mounting frame 51
mounting method 158, 167
multi actuator circuit 218, 292
multi stage piston compressor 31
gas laws 11
gauge pressure 8
gay-Lussac’s law 14
general gas equation 15
general maintenance 487
General troubleshooting procedure 494
group changing valve 231, 237
hardwired control system 424
heavy force 21
high force 22
humidity 28, 41
safety 6, 31, 50, 124, 359, 493
safety devices 134, 201
screw compressor 10, 34
sealing force 126
secondary treatment of compressed air 27, 39
selection and specification of compressors 39514 Index
temperature gauge 50
throttle valve 190
timers 19, 201, 359
turbo compressors 37
two pressure valve 158, 163
two-hand safety measure 198
sensor 2, 19, 107, 191, 205, 362, 464
sensor, directly mounted 108
servicing 491
set coil, PLC 433
shift register 234
signal conflict elimination 219, 231, 234
signal flow 221, 242
signal flow diagram 339
signal overlap 191, 396
single acting cylinder 93-94
single cylinder compressor 29
single stage compressor, 31
solenoid valve 173, 356, 391, 394
solenoids 352, 356
step counter 246
step counter method 245
supply air throttling 190
up counter 367, 433
user program, PLC 426, 427
vacuum 8-9
valve sizing 167, 173
valves 17
van der Waals forces 42
vane motor 22, 125
vee type radial piston motor 126
velocity energy 37
venting type pressure regulator 65
tandem cylinder 93, 102
telescopic cylinder 93, 101
working pressure 48, 183