pneumatic circuits.ppt
TRANSCRIPT
-
8/21/2019 Pneumatic circuits.ppt
1/134
Basic Pneumatic Circuitry
For control and automation
-
8/21/2019 Pneumatic circuits.ppt
2/134
Contents
Symbols
Circuit layout
Actuator control 2/2 Valve
Actuator control 3/2 Valve Actuator control 5/2 Valve
Sequence solution
5/3 Valves
Poppet/spool logic
Balanced spool logic Feedbac
Sequential control
Clic t!e section to advance directly to it
"ntroduction
-
8/21/2019 Pneumatic circuits.ppt
3/134
"ntroduction
#!is module s!o$s t!emet!ods o% application o%
pneumatic valves and
components %or control
and automation
#!e met!ods o% purepneumatic sequential
control are con%ined to
simple e&les
#!e ma'ority o% modern
systems are controlledelectronically and is t!e
sub'ect o% electro(
pneumatic modules
A message to pneumaticcircuit designers) *se proven and reliable
design tec!niques
Produce circuits and
documentation t!at areclear to read
+esign %or sa%ety
+o not try to be too
clever, t!e circuit $ill be
di%%icult %or ot!ers to
read and maintain
-
8/21/2019 Pneumatic circuits.ppt
4/134
Symbols
#!e standard %or %luid po$er symbols is "S- .2.(.0 #!isis a set o% basic s!apes and rules %or t!e construction o%
%luid po$er symbols
Cylinders can be dra$n to s!o$ t!eir e&treme or
intermediate positions o% stroe and any lengt! above
t!eir $idt! Valves s!o$ all states in t!e one symbol0 #!e prevailing
state is s!o$n $it! t!e port connections
-t!er components are single state symbols
-
8/21/2019 Pneumatic circuits.ppt
5/134
Symbols single acting actuators
Single acting, sprunginstroed
Single acting, sprung
outstroed
Single acting, sprung
instroed, magnetic
Single acting, sprung
outstroed, magnetic
-
8/21/2019 Pneumatic circuits.ppt
6/134
Symbols double acting actuators
+ouble acting, non(cus!ioned
+ouble acting, ad'ustable
cus!ions
+ouble acting, t!roug!
rod, ad'ustable cus!ions
+ouble acting, magnetic,
ad'ustable cus!ions
+ouble acting, rodless,
magnetic, ad'ustablecus!ions
-
8/21/2019 Pneumatic circuits.ppt
7/134
Symbols rotary actuators
Semi(rotary double acting 1otary motor single
direction o% rotation
1otary motor bi(
directional
-
8/21/2019 Pneumatic circuits.ppt
8/134
Symbols valves
2/2 Valve pus! button /spring
3/2 Valve pus! button /
spring
3/2 Valve detented leveroperated
2
13
12 10
21012
1
1
2
312
10
-
8/21/2019 Pneumatic circuits.ppt
9/134
Symbols valves
3/2 Valve di%%erentialpressure operated
5/2 Valve pus! button /
spring
5/3 Valve double pressureoperated spring centre
1
24
5 3
14 12
1
24
5 3
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
10/134
Symbols valves
A valve %unction is no$n by a pair o% numbers e0g0 3/20 #!isindicates t!e valve !as 3 main ports and 2 states
#!e valve symbol s!o$s bot! o% t!e states
Port numbering is to C#-P 1P4P and s!o$s) $!en t!e valve is operated at t!e .2 end port . is connected to port 2
$!en reset to t!e normal state at t!e . end port . is connected tonot!ing 67
2
13
12 10
-
8/21/2019 Pneumatic circuits.ppt
11/134
Symbols valves
A valve %unction is no$n by a pair o% numbers e0g0 3/20 #!isindicates t!e valve !as 3 main ports and 2 states
#!e valve symbol s!o$s bot! o% t!e states
Port numbering is to C#-P 1P4P and s!o$s) $!en t!e valve is operated at t!e .2 end port . is connected to port 2
$!en reset to t!e normal state at t!e . end port . is connected tonot!ing 67
2
13
12 10
-
8/21/2019 Pneumatic circuits.ppt
12/134
Symbols valves
#!is e&le is %or a 5/2valve
#!is !as 5 main ports and
2 states
8!en t!e valve is
operated at t!e .9 endport . is connected to port
9 6also port 2 is connected
to port 37
8!en reset to t!e normal
state at t!e .2 end port .is connected to port 2
6also port 9 is connected
to port 57
1
24
5 3
14 12
-
8/21/2019 Pneumatic circuits.ppt
13/134
Symbols valves
#!is e&le is %or a 5/2valve
#!is !as 5 main ports and
2 states
8!en t!e valve is
operated at t!e .9 endport . is connected to port
9 6also port 2 is connected
to port 37
8!en reset to t!e normal
state at t!e .2 end port .is connected to port 2
6also port 9 is connected
to port 57
1
24
5 3
14 12
-
8/21/2019 Pneumatic circuits.ppt
14/134
Symbols operators manual
:eneral manual
Pus! button
Pull button
Pus!/pull button
;ever
Pedal
#readle
1otary nob
-
8/21/2019 Pneumatic circuits.ppt
15/134
Symbols operators mec!anical
Plunger
Spring normallyas a return
1oller
*ni(direction
or one $ay trip
Pressure
Pilot pressure
+i%%erential pressure
+etent in 3 positions
-
8/21/2019 Pneumatic circuits.ppt
16/134
Symbols 5/3 valves
All valves types s!o$n in t!e normal position
#ype .0 All ports bloced
#ype 20 -utlets to e&!aust
#ype 30 Supply to outlets
-
8/21/2019 Pneumatic circuits.ppt
17/134
Symbols %unction components
Silencer
?uic e&!aust valve $it!
silencer
Pressure to electric
s$itc! ad'ustable
@
-
8/21/2019 Pneumatic circuits.ppt
18/134
Symbols air line equipment
8ater separator $it!automatic drain
Filter $it! manual drain
Filter $it! automatic drain
Filter $it! automatic drain
and service indicator
;ubricator
Pressure regulator $it!
gauge
F010;0 %ilter, regulator,
lubricator simpli%ied
symbol
-
8/21/2019 Pneumatic circuits.ppt
19/134
Circuit layout
#!e standard %or circuitdiagrams is "S- .2.(2
A9 %ormat or A3 %olded to
A9 !eig!t %or inclusion in
a manual $it! ot!er A9
documentation #o be on several s!eets i%
necessary $it! line
identi%ication code
inimum crossing lines
;imit valves position o%operation by actuators
s!o$n by a marer $it!
re%erence code to symbol
Circuits s!ould be dra$n
$it! all actuators at t!e
top o% t!e page in order o%
sequential operation
-t!er components to be
dra$n in sequential order
%rom t!e bottom up and
%rom le%t to rig!t
Circuit s!ould s!o$ t!e
system $it! pressure
applied and ready to start
-
8/21/2019 Pneumatic circuits.ppt
20/134
Component identi%ication
#!e "S- suggestedcomponent numbering
system is suited %or large
circuits and t!ose dra$n
on several pages
For t!is presentation asimple code is used
For cylinders) A,B,C etc0
For associated %eedbac
valves) alp!a(numeric
code =a> %or proo% o%instroe, =a.> %or proo% o%
outstroe
For cylinder B) b and b.
A
a0 a1
1
2
3
12 10
a0
2
13
12 10
a1
-
8/21/2019 Pneumatic circuits.ppt
21/134
&le circuit
1un/nd
A
a0 a1
B
b0 b1
C
c0 c1
a0 a1 b0b1 c0c1
. bar ma& bar #o all inlet ports mared
Sequence
1un/nd
A
BB(
C
C(
A(
1epeat
-
8/21/2019 Pneumatic circuits.ppt
22/134
Actuator control 2/2 valve
-
8/21/2019 Pneumatic circuits.ppt
23/134
2/2 Valve actuator control
A pair o% t!e most basico% all valve types t!e 2/2
can be used to control a
single acting cylinder
#!e normally closed
position o% t!e valve isproduced by t!e spring
#!e operated position is
produced by t!e pus!
button
-ne valve admits air t!eot!er valve e&!austs it
21012
1
11012
2-*# "<
-
8/21/2019 Pneumatic circuits.ppt
24/134
2/2 Valve actuator control
#!e button mared -*#is pus!ed to operate t!e
valve
Air is connected to t!e
cylinder and it outstroes
Air cannot escape toatmosp!ere t!roug! t!e
valve mared "< as t!is is
closed
#!e air at atmosp!eric
pressure in t!e %ront o%t!e cylinder vents
t!roug! t!e breat!er port
210
1
1211012
2-*# "<
-
8/21/2019 Pneumatic circuits.ppt
25/134
2/2 Valve actuator control
#!e pus! button o% t!evalve mared -*# is
released and it returns to
a normal closed position
Air is no$ trapped in t!e
system and providedt!ere are no leas t!e
piston rod $ill stay in t!e
outstroed position
"% t!e load increases
beyond t!e %orce e&ertedby t!e air t!e piston rod
$ill start to move in
210
1
1211012
2-*# "<
-
8/21/2019 Pneumatic circuits.ppt
26/134
2/2 Valve actuator control
#!e button mared "< ispus!ed to operate t!e
valve
Air escapes and t!e
piston rod moves to t!e
instroed position #!e pus! button must be
!eld operated until t!e
piston rod is %ully in
Atmosp!eric air $ill be
dra$n in to t!e %ront o%t!e cylinder t!roug! t!e
vent port
210
1
121
2
1012
-*# "<
-
8/21/2019 Pneumatic circuits.ppt
27/134
2/2 Valve actuator control
"% t!e button mared "< isreleased t!e piston rod
$ill remain in t!e
instroed position
Any leas in t!e
installation can cause t!episton rod to creep
210
1
121
2
1012
-*# "<
-
8/21/2019 Pneumatic circuits.ppt
28/134
2/2 Valve actuator control
#o control t!e speed o%t!e piston rod, %lo$
restrictors are placed in
t!e pipes close to eac! o%
t!e valves0
Ad'ustment o% t!erestrictors $ill slo$ do$n
t!e %lo$ rate t!ereby
giving independent
outstroe and instroe
speed control
1012 1012
-*# "<
2
1
1
2
-
8/21/2019 Pneumatic circuits.ppt
29/134
2/2 Valve actuator control
By repeated operation o%eit!er button during
movement t!e piston rod
can be moved in small
steps %or appro&imate
positioning #!is $ill only be
success%ul under slo$
speeds1012 1012
-*# "<
2
1
1
2
-
8/21/2019 Pneumatic circuits.ppt
30/134
2/2 Valve actuator control
8it! any compressed airsystem t!at intentionally
traps air, t!e potential
!aard o% t!is must be
recognised
*nintended release orapplication o% pressure
can give rise to
une&pected movement o%
t!e piston rod
A pressure indicator orgauge must be %itted to
$arn o% t!e presence o%
pressure
210
1
121
2
1012
-*# "<
-
8/21/2019 Pneumatic circuits.ppt
31/134
Actuator control 3/2 valve
-
8/21/2019 Pneumatic circuits.ppt
32/134
3/2 valve actuator control
A 3 port valve provides t!einlet and e&!aust pat! and
is t!e normal c!oice %or
t!e control o% a single
acting cylinder
"n t!e normal positionproduced by t!e spring,
t!e valve is closed
"n t!e operated position
produced by t!e pus!
button t!e valve is open #!e pus! button must be
!eld do$n %or as long as
t!e cylinder is outstroed
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
33/134
3/2 valve actuator control
A 3 port valve provides t!einlet and e&!aust pat! and
is t!e normal c!oice %or
t!e control o% a single
acting cylinder
"n t!e normal positionproduced by t!e spring,
t!e valve is closed
"n t!e operated position
produced by t!e pus!
button t!e valve is open #!e pus! button must be
!eld do$n %or as long as
t!e cylinder is outstroed
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
34/134
3/2 valve actuator control
A 3 port valve provides t!einlet and e&!aust pat! and
is t!e normal c!oice %or
t!e control o% a single
acting cylinder
"n t!e normal positionproduced by t!e spring,
t!e valve is closed
"n t!e operated position
produced by t!e pus!
button t!e valve is open #!e pus! button must be
!eld do$n %or as long as
t!e cylinder is outstroed
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
35/134
3/2 valve actuator control
#o generally slo$ t!ecylinder speed an
ad'ustable
bi(directional %lo$
regulator or %i&ed
restrictor can be used #!e %lo$ regulator
setting $ill be a
compromise as t!e ideal
outstroe speed may not
produce t!e desiredresults %or t!e instroe
speed
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
36/134
3/2 valve actuator control
#o control t!e outstroespeed o% a single acting
cylinder $it!out
controlling t!e instroe
speed, a uni(directional
%lo$ regulator is used #!e %lo$ into t!e cylinder
closes t!e non return
valve and can only pass
t!roug! t!e ad'ustable
restrictor By ad'usting t!e restrictor
t!e outstroe speed o% t!e
cylinder can be set
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
37/134
3/2 valve actuator control
For independent speedcontrol in eac! direction
t$o %lo$ regulators are
required
"nstalled in opposite
directions to eac! ot!er *pper regulator controls
t!e outstroe speed
;o$er regulator controls
t!e instroing speed 1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
38/134
3/2 valve actuator control
A 3 port valve provides t!einlet and e&!aust pat! and
is t!e normal c!oice %or
t!e control o% a single
acting cylinder
"n t!e normal positionproduced by t!e spring,
t!e valve is closed
"n t!e operated position
produced by t!e pus!
button t!e valve is open #!e pus! button must be
!eld do$n %or as long as
t!e cylinder is outstroed
1
2
3
12 10
-
8/21/2019 Pneumatic circuits.ppt
39/134
Actuator control 5/2 valve
-
8/21/2019 Pneumatic circuits.ppt
40/134
5/2 Valve actuator control
For a double acting cylindert!e po$er and e&!aust
pat!s are s$itc!ed
simultaneously
8!en t!e button is pus!ed
t!e supply at port . is
connected to port 9 and t!e
outlet port 2 connected to
e&!aust port 30 #!e cylinder
moves plus
8!en t!e button is released
port . is connected to port 2and port 9 connected to
port 50 Cylinder minus
1
24
5 3
14 12
(
-
8/21/2019 Pneumatic circuits.ppt
41/134
5/2 Valve actuator control
For a double acting cylindert!e po$er and e&!aust
pat!s are s$itc!ed
simultaneously
8!en t!e button is pus!ed
t!e supply at port . is
connected to port 9 and t!e
outlet port 2 connected to
e&!aust port 30 #!e cylinder
moves plus
8!en t!e button is released
port . is connected to port 2and port 9 connected to
port 50 Cylinder minus
1
24
5 3
14 12
(
-
8/21/2019 Pneumatic circuits.ppt
42/134
5/2 Valve actuator control
"ndependent speedcontrol o% t!e plus and
minus movements
"n most applications
speed is controlled by
restricting air out o% acylinder
Full po$er is developed
to drive t!e piston $it!
speed controlled by
restricting t!e bacpressure
1
24
5 3
14 12
(
-
8/21/2019 Pneumatic circuits.ppt
43/134
5/2 Valve actuator control
"ndependent speedcontrol o% t!e plus and
minus movements
"n most applications
speed is controlled by
restricting air out o% acylinder
Full po$er is developed
to drive t!e piston $it!
speed controlled by
restricting t!e bacpressure
1
24
5 3
14 12
(
-
8/21/2019 Pneumatic circuits.ppt
44/134
5/2 Valve actuator control
Valves $it! a spring returnare mono(stable and need
t!e operator to be !eld all
t!e time t!at t!e cylinder is
required in t!e plus position
Bi(stable valves $ill stay in
t!e position t!ey $ere last
set
#!e lever valve e&le
illustrated indicates a
detent mec!anism0 #!e
lever need not be !eld oncet!e ne$ position !as been
establis!ed
1
24
5 3
14 12
(
-
8/21/2019 Pneumatic circuits.ppt
45/134
anual control
1emote manual control o%a double acting cylinder
Valve mared $ill cause
t!e cylinder to outstroe
or move plus
Valve mared ( $ill causet!e cylinder to instroe or
move minus
#!e 5/2 double pilot valve
is bi(stable t!ere%ore t!e
pus! button valves onlyneed to be pulsed
1
24
5 3
14 12
1
2
3
12 10
1
2
3
12 10
(
(
-
8/21/2019 Pneumatic circuits.ppt
46/134
anual control
1emote manual control o%a double acting cylinder
Valve mared $ill cause
t!e cylinder to outstroe
or move plus
Valve mared ( $ill causet!e cylinder to instroe or
move minus
#!e 5/2 double pilot valve
is bi(stable t!ere%ore t!e
pus! button valves onlyneed to be pulsed
1
24
5 3
1
2
3
12 10
1
2
3
12 10
14 12
(
(
-
8/21/2019 Pneumatic circuits.ppt
47/134
anual control
1emote manual control o%a double acting cylinder
Valve mared $ill cause
t!e cylinder to outstroe
or move plus
Valve mared ( $ill causet!e cylinder to instroe or
move minus
#!e 5/2 double pilot valve
is bi(stable t!ere%ore t!e
pus! button valves onlyneed to be pulsed
1
24
5 3
1
2
3
12 10
1
2
3
12 10
14 12
(
(
-
8/21/2019 Pneumatic circuits.ppt
48/134
anual control
1emote manual control o%a double acting cylinder
Valve mared $ill cause
t!e cylinder to outstroe
or move plus
Valve mared ( $ill causet!e cylinder to instroe or
move minus
#!e 5/2 double pilot valve
is bi(stable t!ere%ore t!e
pus! button valves onlyneed to be pulsed
1
24
5 3
14 12
1
2
3
12 10
1
2
3
12 10
(
(
-
8/21/2019 Pneumatic circuits.ppt
49/134
anual control
1emote manual control o%a double acting cylinder
Valve mared $ill cause
t!e cylinder to outstroe
or move plus
Valve mared ( $ill causet!e cylinder to instroe or
move minus
#!e 5/2 double pilot valve
is bi(stable t!ere%ore t!e
pus! button valves onlyneed to be pulsed
1
24
5 3
14 12
1
2
3
12 10
1
2
3
12 10
(
(
-
8/21/2019 Pneumatic circuits.ppt
50/134
Semi(automatic control
anual remote start o% adouble acting cylinder
$it! automatic return
Cylinder identi%ied as DAE
#rip valve operated at t!e
completion o% t!e plusstroe identi%ied as Da.E
1
24
5 3
14 12
1
2
3
12 10
1
2
3
12 10
(
(
A
a1
a1
-
8/21/2019 Pneumatic circuits.ppt
51/134
Fully(automatic control
Continuous automaticcycling %rom roller
operated trip valves
anual 1un and nd o%
t!e automatic cycling
Cylinder $ill come to restin t!e instroed position
regardless o% $!en t!e
valve is put to nd
#ags %or t!e roller
%eedbac valves a anda. s!o$ t!eir relative
positions
1
24
5 3
14 12
2
13
12 10
1
2
3
12 10
1
2
312
10
Run/End
(
A
a0 a1
a0 a1
-
8/21/2019 Pneumatic circuits.ppt
52/134
Sequential control
-
8/21/2019 Pneumatic circuits.ppt
53/134
Circuit building blocs
#!ese circuits can be considered as building blocs %or
larger sequential circuits consisting o% t$o or more cylinders
ac! actuator $ill !ave a po$er valve and t$o associated
%eedbac valves0 #!e %irst actuator to move also !as
a 1un/nd valve
1un/nd
A B
a0 a1 b0 b1
-
8/21/2019 Pneumatic circuits.ppt
54/134
1epeat pattern sequence
A repeat patternsequence is one $!ere
t!e order o% t!e
movements in t!e %irst
!al% o% t!e sequence is
repeated in t!e second!al%
ac! actuator may !ave
one -ut and "n stroe
only in t!e sequence
#!ere may be any numbero% actuators in t!e
sequence
#!e signal starting t!e%irst movement must pass
t!roug! t!e 1un/nd
valve
-
8/21/2019 Pneumatic circuits.ppt
55/134
1epeat pattern sequence
#!e t$o cylinders A and B are to per%orm a simple repeat pattern
sequence as %ollo$s) A B A( B(
Apply t!e rule D#!e signal given by t!e completion o% eac! movement $ill
initiate t!e ne&t movementE
"n t!is $ay t!e roller valves can be
identi%ied and labelled
1un/nd
A B
a0a1b0 b1
a0 a1 b0 b1
-
8/21/2019 Pneumatic circuits.ppt
56/134
1epeat pattern sequence
For t!ree cylinders A, B and C also to per%orm a simple
repeat pattern sequence as %ollo$s) A B C A( B( C( Apply t!e rule D#!e signal given by t!e completion o% eac!
movement $ill initiate t!e ne&t movementE
1un/nd
A
c0 c1
a0 a1
B
a0a1
b0 b1
C
b0b1
c0 c1
-
8/21/2019 Pneumatic circuits.ppt
57/134
-
8/21/2019 Pneumatic circuits.ppt
58/134
-pposed signals
8!en t!e valve is set to 1un, cylinder A $ill not move because t!e
5/2 valve !as an opposed signal, it is still being signalled to !old
position by t!e %eedbac valve b
"% A $as able to move a similar problem $ill occur %or t!e 5/2 valve
o% B once it $as
#!e sequence is A B B( A(
1un/nd
A B
b1a1a0 b0
a0 a1 b0 b1
-
8/21/2019 Pneumatic circuits.ppt
59/134
ec!anical solution
#!e problem $as caused by valves b and a. being
operated at t!e time t!e ne$ opposing instruction is given "% t!ese t$o valves $ere Done $ay tripE types and over
tripped at t!e last movement o% stroe, only a pulse $ould
be obtained instead o% a continuous signal
1un/nd
A B
b1a1a0
a0 a1 b0 b1
b0
-
8/21/2019 Pneumatic circuits.ppt
60/134
Sequence solution met!ods
#!e main solutions tosolving sequences are) Cascade 6pneumatic7
S!i%t register 6pneumatic7
lectro(pneumatic
P;C 6Programmablelogic controller7
Cascade circuits provide a
standard met!od o%
solving any sequence0 "t
uses a minimum o%
additional logic !ard$are
6one logic valve per group
o% sequential steps7
S!i%t register circuits aresimilar to cascade but use
one logic valve %or every
step
lectro(pneumatic circuits
use solenoid valves andelectro(mec!anical relays
P;C0 #!e standard
solution %or medium to
comple& sequential
systems 6e&cept $!ereelectrical equipment
cannot be used7
-
8/21/2019 Pneumatic circuits.ppt
61/134
Cascade t$o group
#!e A B B( A( circuit issolved by t!e t$o group
cascade met!od
#!e sequence is divided at
t!e point $!ere B
immediately returns #!e t$o parts are
allocated groups l and ll
:p l A B / :p ll B( A(
#$o signal supplies are
provided %rom a 5/2 valveone is available only in
group l t!e ot!er is
available only in group ll
Because only one groupoutput is available at a
time it is not possible to
!ave opposed signals
A standard 5/2 double
pressure operated valveis t!e cascade valve
1
24
5 3
14 12
Group l Group ll
Select l Select ll
-
8/21/2019 Pneumatic circuits.ppt
62/134
Cascade 6t$o group7
A B
a1
b0
a0 a1 b0 b1
1un/nd
a0 b1
Sequence
:p l A B :p ll B( A(
:p l
:p ll
-
8/21/2019 Pneumatic circuits.ppt
63/134
Cascade 6t$o group7
A B
a1
b0
a0 a1 b0 b1
1un/nd
a0 b1
Sequence
:p l A B :p ll B( A(
:p l
:p ll
-
8/21/2019 Pneumatic circuits.ppt
64/134
Cascade 6t$o group7
A B
b0
a0 a1 b0 b1
1un/nd
a1
a0 b1
Sequence
:p l A B :p ll B( A(
:p l
:p ll
-
8/21/2019 Pneumatic circuits.ppt
65/134
Cascade 6t$o group7
A B
b0
a0 a1 b0 b1
1un/nd
a1
a0 b1
Sequence
:p l A B :p ll B( A(
:p l
:p ll
-
8/21/2019 Pneumatic circuits.ppt
66/134
Cascade 6t$o group7
A B
a0 a1 b0 b1
1un/nd
a1
a0
Sequence
:p l A B :p ll B( A(
:p l
:p ll
b0
b1
-
8/21/2019 Pneumatic circuits.ppt
67/134
Cascade 6t$o group7
A B
a0 a1 b0 b1
1un/nd
Sequence
:p l A B :p ll B( A(
:p l
:p ll
b0
b1
a1
a0
-
8/21/2019 Pneumatic circuits.ppt
68/134
Cascade building blocs
A t$o group buildingbloc consists o% a lever
valve to run and end t!e
sequence plus t!e 5/2
double pilot operated
cascade valve
For a t$o group system
consisting o% any number
o% cylinders t!is building
bloc and t!e cylinder
building blocs are all
t!at is required to solve
t!e sequence
1
24
5 3
14 12
1
2
312
10
:p l
:p ll
Sel l
Sel ll1un/nd
-
8/21/2019 Pneumatic circuits.ppt
69/134
Cascade building blocs
:p l
:p ll
Sel lSel ll
:p lll
Sel lll
1un/nd
#!is t!ree groupbuilding bloc
establis!es an
interconnecting
pattern t!at can
be e&tended to
any number o%
groups
-
8/21/2019 Pneumatic circuits.ppt
70/134
+ual trip building blocs
8!en a sequence !as acylinder operating t$ice in
one overall sequence a
dual trip building bloc
may be required %or eac!
o% t!e t$o %eedbac valves
#!e supply $ill be %rom
di%%erent groups and t!e
output go to di%%erent
destinations
&le is %or %eedbac
valve a. o% cylinder A
$!en A is sent bot! in
:roup & and :roup y
Send A
A in
:roup &A in
:roup y
a.
a. in &
a. in y
-
8/21/2019 Pneumatic circuits.ppt
71/134
Cascade rules
stablis! t!e correctsequence
+ivide t!e sequence in to
groups0 Al$ays start a
sequence $it! t!e
1un/nd valve selecting
group l e0g0
1/ | A B | B( C | C( A(
Select t!e cylinder
building blocs
Select t!e cascade
building bloc
Select dual trip building
blocs i% required
"nterconnect t!e blocs as
%ollo$s)
#!e %irst %unction in eac! group
is signalled directly by t!at
group supply
#!e last trip valve operated in
eac! group is supplied $it!
main supply air and selects t!e
ne&t group
#!e remaining trip valves are
supplied $it! air %rom t!eir
respective groups and initiate
t!e ne&t %unction
#!e Drun/endE valve $ill controlt!e signal %rom t!e last trip valve
to be operated
-
8/21/2019 Pneumatic circuits.ppt
72/134
#!ree position valves
-
8/21/2019 Pneumatic circuits.ppt
73/134
5/3 Valve
5/3 valves !ave a t!ird midposition
#!e valve can be tri(stable
e0g0 a detented lever
operator or mono(stable
e0g0 a double air or doublesolenoid $it! spring
centre
#!ere are t!ree common
con%igurations %or t!e mid
position) All ports bloced
Centre open e&!aust
Centre open pressure
#!e ma'ority o%applications are actuator
positioning and sa%ety
24
15 3
14 12
14 1224
15 3
14 1224
15 3
-
8/21/2019 Pneumatic circuits.ppt
74/134
5/3 Valve actuator control
#!e valve illustrated !asDall ports blocedE in t!e
mid position
8!enever t!e mid
position is selected t!e
pressure conditions in t!ecylinder $ill be %roen
#!is can be used to stop
t!e piston at part stroe in
some positioning
applications
Flo$ regulators mounted
close to t!e cylinder to
minimise creep
24
15 314 12
-
8/21/2019 Pneumatic circuits.ppt
75/134
5/3 Valve actuator control
#!e valve illustrated !asDall ports blocedE in t!e
mid position
8!enever t!e mid
position is selected t!e
pressure conditions in t!e
cylinder $ill be %roen
#!is can be used to stop
t!e piston at part stroe in
some positioning
applications
Flo$ regulators mounted
close to t!e cylinder to
minimise creep
24
15 314 12
-
8/21/2019 Pneumatic circuits.ppt
76/134
5/3 Valve actuator control
#!e valve illustrated !asDall ports blocedE in t!e
mid position
8!enever t!e mid
position is selected t!e
pressure conditions in t!e
cylinder $ill be %roen
#!is can be used to stop
t!e piston at part stroe in
some positioning
applications
Flo$ regulators mounted
close to t!e cylinder to
minimise creep
24
15 314 12
-
8/21/2019 Pneumatic circuits.ppt
77/134
5/3 Valve actuator control
#!e valve illustrated !asDall ports blocedE in t!e
mid position
8!enever t!e mid
position is selected t!e
pressure conditions in t!e
cylinder $ill be %roen
#!is can be used to stop
t!e piston at part stroe in
some positioning
applications
Flo$ regulators mounted
close to t!e cylinder to
minimise creep
24
15 314 12
-
8/21/2019 Pneumatic circuits.ppt
78/134
5/3 Valve actuator control
#!e valve illustrated !asDall ports blocedE in t!e
mid position
8!enever t!e mid
position is selected t!e
pressure conditions in t!e
cylinder $ill be %roen
#!is can be used to stop
t!e piston at part stroe in
some positioning
applications
Flo$ regulators mounted
close to t!e cylinder to
minimise creep
24
15 314 12
-
8/21/2019 Pneumatic circuits.ppt
79/134
5/3 Valve actuator control
#!is version o% a 5/3 valveis Dcentre open e&!austE
#!e supply at port . is
isolated and t!e cylinder
!as po$er e&!austed
$!en t!is centre position
is selected
#!e version illustrated
s!o$s a mono(stable
version double pilot
operated spring centre
#!e cylinder $ill be pre(
e&!austed $!en c!anging
%rom t!e mid position
24
15 3
14 12
-
8/21/2019 Pneumatic circuits.ppt
80/134
5/3 Valve actuator control
#!is version o% a 5/3 valveis Dcentre open pressureE
#!e supply at port . is
connected to bot! sides
o% t!e cylinder and t!e
e&!aust ports isolated
$!en t!is centre position
is selected
Can be used to balance
pressures in positioning
applications
#!e version illustrated is
mono(stable, double
solenoid, spring centre
1
24
5 3
14 12
-
8/21/2019 Pneumatic circuits.ppt
81/134
;ogic %unctions %or poppet and
spool valves
-
8/21/2019 Pneumatic circuits.ppt
82/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
83/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
84/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
85/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
86/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
87/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
88/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
89/134
;ogic A
-
8/21/2019 Pneumatic circuits.ppt
90/134
;ogic -1
*se o% an =-1> %unctions!uttle valve
Source G and H can be
remote %rom eac! ot!er
and remote %rom t!e
destination o% 8!en G or H is operated
t!e s!uttle valve seal
moves across to prevent
t!e signal %rom being
lost t!roug! t!e e&!austo% t!e ot!er valve
G
H
1
2
3
12 10
1
2
3
12 10
; i -1
-
8/21/2019 Pneumatic circuits.ppt
91/134
;ogic -1
*se o% an =-1> %unctions!uttle valve
Source G and H can be
remote %rom eac! ot!er
and remote %rom t!e
destination o% 8!en G or H is operated
t!e s!uttle valve seal
moves across to prevent
t!e signal %rom being
lost t!roug! t!e e&!aust
o% t!e ot!er valve
G
H
1
2
3
12 10
1
2
3
12 10
; i -1
-
8/21/2019 Pneumatic circuits.ppt
92/134
;ogic -1
*se o% an =-1> %unctions!uttle valve
Source G and H can be
remote %rom eac! ot!er
and remote %rom t!e
destination o% 8!en G or H is operated
t!e s!uttle valve seal
moves across to prevent
t!e signal %rom being
lost t!roug! t!e e&!aust
o% t!e ot!er valve
G
H
1
2
3
12 10
1
2
3
12 10
; i -1
-
8/21/2019 Pneumatic circuits.ppt
93/134
;ogic -1
*se o% an =-1> %unctions!uttle valve
Source G and H can be
remote %rom eac! ot!er
and remote %rom t!e
destination o% 8!en G or H is operated
t!e s!uttle valve seal
moves across to prevent
t!e signal %rom being
lost t!roug! t!e e&!aust
o% t!e ot!er valve
G
H
1
2
3
12 10
1
2
3
12 10
;ogic -1
-
8/21/2019 Pneumatic circuits.ppt
94/134
;ogic -1
*se o% an =-1> %unctions!uttle valve
Source G and H can be
remote %rom eac! ot!er
and remote %rom t!e
destination o% 8!en G or H is operated
t!e s!uttle valve seal
moves across to prevent
t!e signal %rom being
lost t!roug! t!e e&!aust
o% t!e ot!er valve
G
H
1
2
3
12 10
1
2
3
12 10
;ogic
-
8/21/2019 Pneumatic circuits.ppt
95/134
;ogic
-
8/21/2019 Pneumatic circuits.ppt
96/134
;ogic
-
8/21/2019 Pneumatic circuits.ppt
97/134
;ogic
-
8/21/2019 Pneumatic circuits.ppt
98/134
;ogic -1H
A logic -1H allo$s
t!e output signal state
6-< or -FF7 to be
maintained a%ter t!e input
signal !as been removed
Any bi(stable valve is a
logic -1H
8it! t!is lever detented
valve, once t!e lever !as
been moved G direction
or H direction it can be
released and $ill stay in
t!at position
G
1310
H
12
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
99/134
;ogic -1H
A logic -1H allo$s
t!e output signal state
6-< or -FF7 to be
maintained a%ter t!e
signal t!at set it !as been
removed
G13
12 10 H
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
100/134
;ogic -1H
A bi(stable double pilot
valve can be set or reset
simply by a pulse 6pus!
and release7 on buttons G
or H
13
G
H1
2
3
12 10
1
2
3
12 10
12 10
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
101/134
;ogic -1H
A bi(stable double pilot
valve can be set or reset
simply by a pulse 6pus!
and release7 on buttons G
or H
13
G
H1
2
3
12 10
1
2
3
12 10
12 10
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
102/134
;ogic -1H
A bi(stable double pilot
valve can be set or reset
simply by a pulse 6pus!
and release7 on buttons G
or H
13
G
H1
2
3
12 10
1
2
3
12 10
12 10
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
103/134
;ogic -1H
A bi(stable double pilot
valve can be set or reset
simply by a pulse 6pus!
and release7 on buttons G
or H
13
G
H1
2
3
12 10
1
2
3
12 10
12 10
;ogic -1H
-
8/21/2019 Pneumatic circuits.ppt
104/134
;ogic -1H
A bi(stable double pilot
valve can be set or reset
simply by a pulse 6pus!
and release7 on buttons G
or H
13
G
H1
2
3
12 10
1
2
3
12 10
12 10
;ogic -1H 6latc!7
-
8/21/2019 Pneumatic circuits.ppt
105/134
;ogic -1H 6latc!7
A popular memory circuit
is t!e latc!
8ill not re(mae a%ter
pneumatic po$er %ailure
A pulse on G operates t!e
pilot / spring valve to give
output
A %eedbac %rom runs
t!roug! t!e normally open
valve H to latc! t!e
operation o% $!en G is
released
A pulse on H breas t!e
latc! and is e&!austed
G
H
13
1
2
3
12 10
1012
3
2
1
12 10
;ogic -1H 6latc!7
-
8/21/2019 Pneumatic circuits.ppt
106/134
;ogic -1H 6latc!7
A popular memory circuit
is t!e latc!
8ill not re(mae a%ter
pneumatic po$er %ailure
A pulse on G operates t!e
pilot / spring valve to give
output
A %eedbac %rom runs
t!roug! t!e normally open
valve H to latc! t!e
operation o% $!en G is
released
A pulse on H breas t!e
latc! and is e&!austed
G
H
13
1
2
3
12 10
12 10
3
2
1
12 10
;ogic -1H 6latc!7
-
8/21/2019 Pneumatic circuits.ppt
107/134
;ogic -1H 6latc!7
A popular memory circuit
is t!e latc!
8ill not re(mae a%ter
pneumatic po$er %ailure
A pulse on G operates t!e
pilot / spring valve to give
output
A %eedbac %rom runs
t!roug! t!e normally open
valve H to latc! t!e
operation o% $!en G is
released
A pulse on H breas t!e
latc! and is e&!austed
G
H
13
1
2
3
12 10
12 10
3
2
1
12 10
;ogic -1H 6latc!7
-
8/21/2019 Pneumatic circuits.ppt
108/134
;ogic -1H 6latc!7
A popular memory circuit
is t!e latc!
8ill not re(mae a%ter
pneumatic po$er %ailure
A pulse on G operates t!e
pilot / spring valve to give
output
A %eedbac %rom runs
t!roug! t!e normally open
valve H to latc! t!e
operation o% $!en G is
released
A pulse on H breas t!e
latc! and is e&!austed
G
H
13
1
2
3
12 10
3
2
1
12 10
12 10
;ogic -1H 6latc!7
-
8/21/2019 Pneumatic circuits.ppt
109/134
;ogic -1H 6latc!7
A popular memory circuit
is t!e latc!
8ill not re(mae a%ter
pneumatic po$er %ailure
A pulse on G operates t!e
pilot / spring valve to give
output
A %eedbac %rom runs
t!roug! t!e normally open
valve H to latc! t!e
operation o% $!en G is
released
A pulse on H breas t!e
latc! and is e&!austed
G
H
13
1
2
3
12 10
3
2
1
12 10
12 10
-
8/21/2019 Pneumatic circuits.ppt
110/134
;ogic arrangements %or %ully
balanced spool valves
;ogic circuits 6spool valves7
-
8/21/2019 Pneumatic circuits.ppt
111/134
;ogic circuits 6spool valves7
Selection / +iversion
;atc!
-1, A
-
8/21/2019 Pneumatic circuits.ppt
112/134
3/2
-
8/21/2019 Pneumatic circuits.ppt
113/134
3/2
-
8/21/2019 Pneumatic circuits.ppt
114/134
3/2 Valve selection / diversion
Selection o% one o% t$o
supplies connected to
ports . and 3 can be
di%%erent pressures
+iversion o% one supply
to one o% t$o outlets
"% it is required to e&!aust
t!e do$nstream air a 5/2
valve is required
1
2
3
12 10
2
13
12 10
3/2 Valve selection / diversion
-
8/21/2019 Pneumatic circuits.ppt
115/134
3/2 Valve selection / diversion
Selection o% one o% t$o
supplies connected to
ports . and 3 can be
di%%erent pressures
+iversion o% one supply
to one o% t$o outlets
"% it is required to e&!aust
t!e do$nstream air a 5/2
valve is required
1
2
3
2
13
12 10
12 10
;atc! $it! controls
-
8/21/2019 Pneumatic circuits.ppt
116/134
;atc! $it! controls
"n t!is version o% a latc!
t!e pus! button valves
are connected to per%orm
=-1> and = %unctions
#!e =-FF> valve must be
placed last in t!e signal
c!ain so t!at i% bot!
valves are operated
toget!er t!e =-FF>
command $ill dominate
over t!e =- command
1
2
3
12 10
2
13
12 10
2
13
12 10
-<
-FF
-ut
-1, A
-
8/21/2019 Pneumatic circuits.ppt
117/134
-1, A
-
8/21/2019 Pneumatic circuits.ppt
118/134
Single pulse maer
Converts a prolonged
signal x into a single
pulse z
Signal must be removed
to allo$ t!e valve to reset
t!en & can be applied
again
#!e duration o% t!e pulse
can be ad'usted $it! t!e
%lo$ regulator
1
2
3
12 10
x
z
Slo$ initial pressure build up
-
8/21/2019 Pneumatic circuits.ppt
119/134
Slo$ initial pressure build up
C!oose a 3/2 pilot spring
valve $it! a relatively
!ig! operating %orce e0g0
3 to 9 bar
8!en t!e quic connect
coupling is made, t!e
output at port 2 is
controlled at t!e rate o%
t!e %lo$ regulator setting
8!en t!e pressure is
!ig! enoug! to operate
t!e valve %ull %lo$ $ill
tae over
1
2
3
12 10
Pre(select
-
8/21/2019 Pneumatic circuits.ppt
120/134
Pre select
#!e lever valve can pre(
select t!e movement o%
t!e cylinder -*# or "<
#!e movement $ill occur
t!e ne&t time t!e plunger
valve is operated
#!e plunger valve can be
released immediately and
subsequently operated
and released any number
o% times
1
2
3
12 10
1
2
3
12 10
1
2
3
12
10
-*#/"<
pre(select
5/2 -1 %unction
-
8/21/2019 Pneumatic circuits.ppt
121/134
5/2 -1 %unction
#!e valve at position =a> is
reversed connected and
supplied %rom t!e valve
conventionally connected
at position =b>
#!e cylinder can be
controlled %rom eit!er
position =a> =-1> position
=b>
1
24
5 3
14 12
1
24
5 3
14 12
a
b
Single pulse control
-
8/21/2019 Pneumatic circuits.ppt
122/134
g p
24
14 12
1
2
3
12 10
15
12 10
1
2
3
2
13
1210
ac! time t!e %oot
operated valve is
pressed t!e cylinder
$ill single stroe
and ( alternately
First %oot operation
t!e cylinder moves
out
Second %oot
operation t!e
cylinder moves in
#!irdI00 out and so
on
Air conservation
-
8/21/2019 Pneumatic circuits.ppt
123/134
Po$er stroe in t!e
instroe direction only
+i%%erential area o% t!e
piston gives an outstroe
%orce $!en t!e pressure
is balanced
Air used to outstroe is
equivalent to a cylinder
$it! only t!e same bore
as t!e rod diameter
Assumes t!e cylinder is
not loaded on t!e plus
stroe and lo$ %riction
24
15
14 12
Air conservation
-
8/21/2019 Pneumatic circuits.ppt
124/134
Po$er stroe in t!e
instroe direction only
+i%%erential area o% t!e
piston gives an outstroe
%orce $!en t!e pressure
is balanced
Air used to outstroe is
equivalent to a cylinder
$it! only t!e same bore
as t!e rod diameter
Assumes t!e cylinder is
not loaded on t!e plus
stroe and lo$ %riction
24
15
14 12
+ouble %lo$
-
8/21/2019 Pneumatic circuits.ppt
125/134
8!ere a larger 3/2 valve
is not available
#$o %lo$ pat!s in a 5/2
valve eac! $it! a
separate supply can be
arranged to give double
%lo$ or supply separate
devices
nsure t!e tube sie to
t!e cylinder is large
enoug! to tae t!e double
%lo$
4 2
1 3
1214
5 1
+ouble %lo$
-
8/21/2019 Pneumatic circuits.ppt
126/134
8!ere a larger 3/2 valve
is not available
#$o %lo$ pat!s in a 5/2
valve eac! $it! a
separate supply can be
arranged to give double
%lo$ or supply separate
devices
nsure t!e tube sie to
t!e cylinder is large
enoug! to tae t!e double
%lo$
4 2
1 3
1214
5
Counting
-
8/21/2019 Pneumatic circuits.ppt
127/134
g
Counting applications are
best ac!ieved $it! electro(mec!anical or
programmable electronic
counters
Pneumatic counting circuits
use large numbers o% logicvalves and can be slo$
#!e counting c!ain s!o$n
$ill count to 9
1ed and blue are non(
overlapping alternatepulses, purple is t!e reset
line
.
2
3
9
Counting application
-
8/21/2019 Pneumatic circuits.ppt
128/134
g pp
#!e counting circuit is
applied to count 9 stroes o%a cylinder
At rest all counting valves
are !eld reset by t!e start
valve
Start outstroes =A> Alternate signals %rom =a.>
and =a> progresses
operation o% t!e counting
valves up t!e c!ain
-n t!e 9t! operation o% =a.>
t!e green signal resets t!e
start valve to stop t!e
cylinder
A
aa.
a a.
Start
-
8/21/2019 Pneumatic circuits.ppt
129/134
Feedbac met!ods
#ime delay
-
8/21/2019 Pneumatic circuits.ppt
130/134
y
A signal is restricted to
slo$ t!e rate o% pressure
build up on a pressure
s$itc! 63/2 di%%erential
pressure operated valve7
8!en t!e pressure s$itc!
operates a strong un(restricted output is given
A reservoir provides
capacitance to allo$ less
%ine and sensitive settings
on t!e %lo$ regulatormaing it easy to ad'ust
1
2
3
12 10
Signal
in
-utput
#ime delay
-
8/21/2019 Pneumatic circuits.ppt
131/134
y
anual remote start o% a
double acting cylinder
$it! a time delay in t!e
outstroed position
be%ore automatic return
2
1
24
5 3
14 12
13
12 10
(
A
a1
1
2
3
12 10
a1
1
2
3
12 10
Pressure decay
-
8/21/2019 Pneumatic circuits.ppt
132/134
y
anual remote start o% a
double acting cylinder
*ses a lo$ pressure
operated valve connected
normally open
8!en t!e bac pressure in
t!e %ront o% t!e cylinder%alls belo$ 0. bar t!e
return signal is given
Connection taen bet$een
t!e cylinder and %lo$
regulator *se%ul %or pressing $or
pieces o% variable sie
1
24
5 3
14 12
2
13
12 10
(
A
a1
21210
1 3 0.bar
lectro(pneumatic
-
8/21/2019 Pneumatic circuits.ppt
133/134
#!e ma'ority o% systems
use electrical/electroniccontrol due to t!e !ig!
degree o% sop!istication
and %le&ibility
Solenoid valves are used to
control cylinders Feedbac signals are %rom
reed s$itc!es, sensors and
electrical limit s$itc!es
;ogic is !ard $ired or
programmed in to a P;C6programmable logic
controller7a a.
1
24
5 3
14 12
A
a a.
Circuit building bloc %or
eac! cylinder
-
8/21/2019 Pneumatic circuits.ppt
134/134
nd