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# Basic Pneumatic Circuitry by ajizai

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```									                                              《气动技术》双语电子教案 吴洪明
Chapter 6

Basic Pneumatic Circuitry
For control and automation

WUHAN UNIVERSITY OF TECHNOLOGY LOGISTICS ENG. DEPT.   武汉理工大学 物流工程系
《气动技术》双语电子教案 吴洪明
Chapter 6

Contents
   Introduction                     Sequential control
   Symbols                          Sequence solution
   Circuit layout                   5/3 Valves
   Actuator control 2/2 Valve       Poppet/spool logic
   Actuator control 3/2 Valve       Balanced spool logic
   Actuator control 5/2 Valve       Feedback

Click the section to advance directly to it
《气动技术》双语电子教案 吴洪明
Chapter 6

Introduction
   This module shows the         A message to pneumatic
methods of application of      circuit designers:
pneumatic valves and               Use proven and reliable
components for control and          design techniques
automation                         Produce circuits and
   The methods of pure                 documentation that are
pneumatic sequential control        clear to read
are confined to simple             Design for safety
examples                           Do not try to be too
   The majority of modern              clever, the circuit will be
systems are controlled              difficult for others to read
electronically and is the           and maintain
subject of electro-pneumatic
modules
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols
   The standard for fluid power symbols is ISO 1219-1. This
is a set of basic shapes and rules for the construction of
fluid power symbols
   Cylinders can be drawn to show their extreme or
intermediate positions of stroke and any length above
their width
   Valves show all states in the one symbol. The prevailing
state is shown with the port connections
   Other components are single state symbols
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols single acting actuators
   Single acting, sprung
instroked
   Single acting, sprung
outstroked
   Single acting, sprung
instroked, magnetic
   Single acting, sprung
outstroked, magnetic
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols double acting actuators
   Double acting, non-
cushioned
cushions
   Double acting, through
   Double acting, magnetic,
   Double acting, rodless,
cushions
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols rotary actuators
   Semi-rotary double
acting
   Rotary motor single
direction of rotation
   Rotary motor bi-
directional
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
2
   2/2 Valve push button    12             10

/ spring                               1

   3/2 Valve push button        12
2
10
/ spring                           3   1

   3/2 Valve detented                     2
10
lever operated          12
3   1
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
   3/2 Valve differential    12
2
10

pressure operated                   3    1

   5/2 Valve push button           4         2
14                12
/ spring
5       1 3

   5/3 Valve double
4        2
pressure operated
spring centre                   5       1 3
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
   A valve function is known by a pair of numbers e.g. 3/2.
This indicates the valve has 3 main ports and 2 states
   The valve symbol shows both of the states
   Port numbering is to CETOP RP68P and shows:
   when the valve is operated at the 12 end port 1 is connected to
port 2
   when reset to the normal state at the 10 end port 1 is connected
to nothing (0)
2
12               10

3    1
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
   A valve function is known by a pair of numbers e.g. 3/2.
This indicates the valve has 3 main ports and 2 states
   The valve symbol shows both of the states
   Port numbering is to CETOP RP68P and shows:
   when the valve is operated at the 12 end port 1 is connected to
port 2
   when reset to the normal state at the 10 end port 1 is connected
to nothing (0)
2
12             10

3   1
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
   This example is for a 5/2
valve
   This has 5 main ports and 2
states
4     2
   When the valve is operated       14             12
at the 14 end port 1 is
connected to port 4 (also             5   1 3
port 2 is connected to port 3)
   When reset to the normal
state at the 12 end port 1 is
connected to port 2 (also
port 4 is connected to port 5)
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols valves
   This example is for a 5/2 valve
   This has 5 main ports and 2
states
   When the valve is operated at
4     2
the 14 end port 1 is connected       14             12
to port 4 (also port 2 is
connected to port 3)                      5   1 3

   When reset to the normal state
at the 12 end port 1 is connected
to port 2 (also port 4 is
connected to port 5)
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols operators manual
General manual     Lever

Push button        Pedal

Push/pull button   Rotary knob
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols operators mechanical
Plunger           Pressure

Spring normally   Pilot pressure
as a return

Roller            Differential pressure

Uni-direction     Detent in 3 positions
or one way trip
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols 5/3 valves
   All valves types shown in the normal position

   Type 1. All ports blocked

   Type 2. Outlets to exhaust

   Type 3. Supply to outlets
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols function components
   Non-return valve
   Flow regulator uni-
directional
   Flow regulator bi-directional
   Two pressure ‘AND’                                         *
   Shuttle valve ‘OR’                            ISO 1219-1   Old

   Silencer
   Quick exhaust valve with
silencer
   Pressure to electric switch
extensive use (preferred)
《气动技术》双语电子教案 吴洪明
Chapter 6

Symbols air line equipment
   Water separator with
automatic drain
   Filter with manual drain
   Filter with automatic drain
   Filter with automatic drain
and service indicator
   Lubricator
   Pressure regulator with
gauge
   F.R.L. filter, regulator,
lubricator simplified symbol
《气动技术》双语电子教案 吴洪明
Chapter 6

Circuit layout
   The standard for circuit        Circuits should be drawn
diagrams is ISO 1219-2           with all actuators at the
top of the page in order of
   A4 format or A3 folded to        sequential operation
A4 height for inclusion in
   Other components to be
a manual with other A4           drawn in sequential order
documentation                    from the bottom up and
   To be on several sheets if       from left to right
necessary with line             Circuit should show the
identification code              system with pressure
   Minimum crossing lines           applied and ready to start
   Limit valves position of
operation by actuators
shown by a marker with
reference code to symbol
《气动技术》双语电子教案 吴洪明
Chapter 6

Component identification
   The ISO suggested                 Note: the a0 valve
component numbering                symbol is drawn in the
system is suited for large         operated position because
circuits and those drawn on        the actuator A is
several pages                      instroked
   For this presentation a                                a0       a1

simple code is used                      A

   For cylinders: A,B,C etc.
   For associated feedback
valves: alpha-numeric code                   2                   2
‘a0’ for proof of instroke,       12             10   12          10

‘a1’ for proof of outstroke       a0 3       1        a1    3    1

   For cylinder B: b0 and b1
《气动技术》双语电子教案 吴洪明
Chapter 6

Example circuit
a0      a1                          b0        b1            c0    c1
A                             B                                 C

Sequence
Run/End
A+
B+
B-
C+
C-
A-
Repeat
Run/End

a0          a1               b1                       b0        c1        c0

10 bar max        6 bar
To all inlet ports marked
《气动技术》双语电子教案 吴洪明
Chapter 6

Actuator control 2/2 valve
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   A pair of the most basic of
all valve types the 2/2 can
be used to control a single
acting cylinder
   The normally closed
position of the valve is
produced by the spring            2          1
   The operated position is 12        10   12    10

produced by the push              1          2
OUT         IN
button
   One valve admits air the
other valve exhausts it
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   The button marked OUT is
pushed to operate the
valve
   Air is connected to the
cylinder and it outstrokes
   Air cannot escape to
atmosphere through the         12
2
10   12
1
10
valve marked IN as this is
closed                      OUT
1
IN
2

   The air at atmospheric
pressure in the front of the
cylinder vents through the
breather port
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   The push button of the
valve marked OUT is
released and it returns to a
normal closed position
   Air is now trapped in the
system and provided there
are no leaks the piston rod          2          1
12     10   12    10
will stay in the outstroked
position                             1          2
OUT         IN
beyond the force exerted
by the air the piston rod
will start to move in
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   The button marked IN is
pushed to operate the valve
   Air escapes and the piston
rod moves to the instroked
position
   The push button must be
held operated until the            2               1
12     10        12       10
piston rod is fully in
1               2
   Atmospheric air will be      OUT         IN
drawn in to the front of the
cylinder through the vent
port
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   If the button marked
IN is released the
piston rod will remain
in the instroked
position
2          1
12    10   12    10
   Any leaks in the
1          2
installation can cause OUT         IN
the piston rod to creep
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   To control the speed of
the piston rod, flow
restrictors are placed in
the pipes close to each of
the valves.
restrictors will slow down             2              1
12         10   12        10
the flow rate thereby
giving independent                 1              2
OUT             IN
outstroke and instroke
speed control
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   By repeated operation
of either button
during movement the
piston rod can be
moved in small steps
for approximate
2              1
positioning             12         10   12        10

   This will only be       OUT
1
IN
2

successful under slow
speeds
《气动技术》双语电子教案 吴洪明
Chapter 6

2/2 Valve actuator control
   With any compressed air
system that intentionally
traps air, the potential
hazard of this must be
recognised
   Unintended release or
application of pressure can 12       2
10   12
1
10
give rise to unexpected
movement of the piston rod OUT   1
IN
2

   A pressure indicator or
gauge must be fitted to
warn of the presence of
pressure
《气动技术》双语电子教案 吴洪明
Chapter 6

Actuator control 3/2 valve
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   A 3 port valve provides the inlet
and exhaust path and is the
normal choice for the control of
a single acting cylinder
   In the normal position produced               2
12        10
by the spring, the valve is closed
3   1
   In the operated position
produced by the push button the
valve is open
   The push button must be held
down for as long as the cylinder
is outstroked
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   A 3 port valve provides the inlet
and exhaust path and is the
normal choice for the control of a
single acting cylinder
   In the normal position produced
2
by the spring, the valve is closed     12       10

   In the operated position produced       3   1
by the push button the valve is
open
   The push button must be held
down for as long as the cylinder is
outstroked
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   A 3 port valve provides the inlet
and exhaust path and is the
normal choice for the control of
a single acting cylinder
   In the normal position produced
2
by the spring, the valve is closed   12        10

   In the operated position                  3   1
produced by the push button the
valve is open
   The push button must be held
down for as long as the cylinder
is outstroked
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   To generally slow the
bi-directional flow regulator
or fixed restrictor can be
used
   The flow regulator setting
will be a compromise as the               2
12        10
ideal outstroke speed may
3   1
not produce the desired
results for the instroke speed
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   To control the outstroke speed
of a single acting cylinder
without controlling the
instroke speed, a uni-
directional flow regulator is
used
   The flow into the cylinder
closes the non return valve and   12
2
10
can only pass through the

   By adjusting the restrictor the
outstroke speed of the cylinder
can be set
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   For independent speed
control in each direction two
flow regulators are required
   Installed in opposite
directions to each other
   Upper regulator controls the             2
12
outstroke speed                           10

   Lower regulator controls the         3   1

instroking speed
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 valve actuator control
   A 3 port valve provides the
inlet and exhaust path and is the
normal choice for the control of
a single acting cylinder
   In the normal position produced
by the spring, the valve is
closed
   In the operated position                     2
12        10
produced by the push button the
valve is open                            3   1

   The push button must be held
down for as long as the cylinder
is outstroked
《气动技术》双语电子教案 吴洪明
Chapter 6

Actuator control 5/2 valve
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 Valve actuator control
   For a double acting cylinder the        -         +

power and exhaust paths are
switched simultaneously
   When the button is pushed the
supply at port 1 is connected to
4    2
port 4 and the outlet port 2       14                 12
connected to exhaust port 3.
5       1 3
The cylinder moves plus
   When the button is released
port 1 is connected to port 2
and port 4 connected to port 5.
Cylinder minus
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 Valve actuator control
-         +
   For a double acting cylinder the
power and exhaust paths are
switched simultaneously
   When the button is pushed the
supply at port 1 is connected to
4    2
port 4 and the outlet port 2         14             12
connected to exhaust port 3. The
5   1 3
cylinder moves plus
   When the button is released port 1
is connected to port 2 and port 4
connected to port 5. Cylinder
minus
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 Valve actuator control
-         +
   Independent speed control
of the plus and minus
movements
   In most applications speed
4    2
is controlled by restricting   14                 12
air out of a cylinder               5       1 3
   Full power is developed to
drive the piston with speed
controlled by restricting
the back pressure
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 Valve actuator control
-         +
   Independent speed control of
the plus and minus movements
   In most applications speed is
controlled by restricting air out
of a cylinder                              4    2
14             12
   Full power is developed to
5   1 3
drive the piston with speed
controlled by restricting the
back pressure
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 Valve actuator control
   Valves with a spring return are             -         +
mono-stable and need the
operator to be held all the time
that the cylinder is required in
the plus position
4     2
   Bi-stable valves will stay in the
position they were last set         14                 12
5       1 3
   The lever valve example
illustrated indicates a detent
mechanism. The lever need not
be held once the new position
has been established
《气动技术》双语电子教案 吴洪明
Chapter 6

Manual control
   Remote manual control of a                        -       +
double acting cylinder
   Valve marked + will cause
the cylinder to outstroke or
move plus
4       2
   Valve marked - will cause              14                     12
the cylinder to instroke or
5   1 3
move minus
   The 5/2 double pilot valve
is bi-stable therefore the    12
2
10           12
2
10
push button valves only
+      3        1         -            3   1
need to be pulsed
《气动技术》双语电子教案 吴洪明
Chapter 6

Manual control
   Remote manual control of a                    -            +

double acting cylinder
   Valve marked + will cause
the cylinder to outstroke or
move plus
4    2
   Valve marked - will cause                    14                 12
the cylinder to instroke or                       5   1 3
move minus
   The 5/2 double pilot valve
2                           2
is bi-stable therefore the         12         10           12         10
push button valves only             3    1                      3    1
+                       -
need to be pulsed
《气动技术》双语电子教案 吴洪明
Chapter 6

Manual control
-           +
   Remote manual control of
a double acting cylinder
   Valve marked + will cause
the cylinder to outstroke or
move plus
4       2
   Valve marked - will cause                    14                12

the cylinder to instroke or                       5   1 3
move minus
   The 5/2 double pilot valve             2                            2
is bi-stable therefore the   12         10                12         10

push button valves only +         3    1              -        3    1
need to be pulsed
《气动技术》双语电子教案 吴洪明
Chapter 6

Manual control
   Remote manual control of a                        -       +
double acting cylinder
   Valve marked + will cause
the cylinder to outstroke or
move plus
4       2
   Valve marked - will cause              14                     12
the cylinder to instroke or
5   1 3
move minus
   The 5/2 double pilot valve
2                               2
is bi-stable therefore the    12             10                    12           10
push button valves only            3        1                           3   1
+                         -
need to be pulsed
《气动技术》双语电子教案 吴洪明
Chapter 6

Manual control
-       +
   Remote manual control of
a double acting cylinder
   Valve marked + will cause
the cylinder to outstroke or
move plus                                        4       2
   Valve marked - will cause             14                     12

the cylinder to instroke or                      5   1 3
move minus
   The 5/2 double pilot valve                 2                          2
is bi-stable therefore the   12             10           12            10

push button valves only +         3        1         -            3   1
need to be pulsed
《气动技术》双语电子教案 吴洪明
Chapter 6

Semi-automatic control
-           +                a1
   Manual remote start                        A
of a double acting
cylinder with
automatic return
4       2
   Cylinder identified as                14                         12

“A”                                                  5   1 3

   Trip valve operated at
the completion of the        12
2
10               12
2
10
plus stroke identified            3        1                     a1   3   1
+                               -
as “a1”
《气动技术》双语电子教案 吴洪明
Chapter 6

Fully-automatic control   -        +        a0           a1
   Continuous automatic
A
cycling from roller
operated trip valves
   Manual Run and End of
4    2
the automatic cycling
14                      12                        Cylinder will come to rest
5   1 3                             in the instroked position
2
10
regardless of when the
12                                                                  valve is put to End
Run/End     3         1
2                                2
   Tags for the roller
12                          12
10                          10          feedback valves a0 and
a0 3        1                  a1        3   1            a1 show their relative
positions
《气动技术》双语电子教案 吴洪明
Chapter 6

Sequential control
《气动技术》双语电子教案 吴洪明
Chapter 6

Circuit building blocks
a0   a1                  b0   b1
A                    B

Run/End

   These circuits can be considered as building blocks for
larger sequential circuits consisting of two or more
cylinders
   Each actuator will have a power valve and two associated
feedback valves. The first actuator to move also has
a Run/End valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Repeat pattern sequence
   A repeat pattern sequence       The signal starting the
is one where the order of        first movement must pass
the movements in the first       through the Run/End
half of the sequence is          valve
repeated in the second          Needs only the basic
half                             building blocks to solve
   Each actuator may have          Examples of repeat
one Out and In stroke            pattern sequences:
only in the sequence            A+ B+ C+ D+ A- B- C-
   There may be any                 D-
number of actuators in          A- B+ C- A+ B- C+
the sequence
   C+ A+ B- C- A- B+
《气动技术》双语电子教案 吴洪明
Chapter 6

Repeat pattern sequence   a0   a1                b0   b1
A                       B

Run/End

b0        b1             a1           a0

   The two cylinders A and B are to perform a simple repeat
pattern sequence as follows: A+ B+ A- B-
   Apply the rule “The signal given by the completion of
each movement will initiate the next movement”
   In this way the roller valves can be identified and labelled
《气动技术》双语电子教案 吴洪明
Chapter 6

Repeat pattern sequence
a0   a1            b0   b1               c0   c1
A                         B                  C

Run/End

c0          c1             a1       a0        b1          b0

        For three cylinders A, B and C also to perform a simple
repeat pattern sequence as follows: A+ B+ C+ A- B- C-
        Apply the rule “The signal given by the completion of
each movement will initiate the next movement”
《气动技术》双语电子教案 吴洪明
Chapter 6

Non-repeat pattern sequence a0   a1                  b0   b1
A                       B

Run/End

a0        b0             a1        b1

   If the rule applied to a repeat pattern sequence is applied
to any other sequence there will be opposed signals on
one or more of the 5/2 valves preventing operation
   This circuit demonstrates the problem
   The sequence is A+ B+ B- A-
《气动技术》双语电子教案 吴洪明
Chapter 6

Opposed signals            a0   a1                 b0   b1
A                       B

Run/End

a0        b0             a1       b1

   When the valve is set to Run, cylinder A will not move
because the 5/2 valve has an opposed signal, it is still
being signalled to hold position by the feedback valve b0
   If A was able to move + a similar problem will occur for
the 5/2 valve of B once it was +
   The sequence is A+ B+ B- A-
《气动技术》双语电子教案 吴洪明
Chapter 6

Mechanical solution        a0   a1                 b0   b1
A                       B

Run/End

a0        b0             a1       b1

   The problem was caused by valves b0 and a1 being
operated at the time the new opposing instruction is given
   If these two valves were “one way trip” types and over
tripped at the last movement of stroke, only a pulse would
be obtained instead of a continuous signal
《气动技术》双语电子教案 吴洪明
Chapter 6

Sequence solution methods
   The main solutions to               Shift register circuits are
solving sequences are:               similar to cascade but use
   Cascade (pneumatic)              one logic valve for every
   Shift register (pneumatic)       step
   Electro-pneumatic               Electro-pneumatic
   PLC (Programmable                circuits use solenoid
logic controller)                valves and electro-
   Cascade circuits provide             mechanical relays
a standard method of                PLC. The standard
solving any sequence. It             solution for medium to
uses a minimum of                    complex sequential
additional logic hardware            systems (except where
(one logic valve per                 electrical equipment
group of sequential steps)           cannot be used)
《气动技术》双语电子教案 吴洪明
Chapter 6

   The A+ B+ B- A- circuit         Because only one group
is solved by the two
group cascade method             output is available at a
   The sequence is divided          time it is not possible to
at the point where B             have opposed signals
immediately returns
   A standard 5/2 double
   The two parts are
allocated groups l and ll        pressure operated valve
   Gp l A+ B+ / Gp ll B- A-         is the cascade valve
   Two signal supplies are            Group l        Group ll
provided from a 5/2 valve                    4    2
one is available only in                14         12
group l the other is         Select l        5   1 3    Select ll
available only in group ll
《气动技术》双语电子教案 吴洪明
Chapter 6

Cascade (two group)   a0        a1                      b0   b1
A                                 B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0                  b1
《气动技术》双语电子教案 吴洪明
Chapter 6

a0        a1                      b0   b1
A                                 B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0                  b1
《气动技术》双语电子教案 吴洪明
Chapter 6

a0        a1                      b0   b1
A                            B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0                   b1
《气动技术》双语电子教案 吴洪明
Chapter 6

a0   a1                      b0   b1
A                       B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0              b1
《气动技术》双语电子教案 吴洪明
Chapter 6

a0        a1                      b0   b1
A                            B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0                   b1
《气动技术》双语电子教案 吴洪明
Chapter 6

Cascade (two group)   a0        a1                      b0   b1
A                                 B

b0

a1
Gp l

Gp ll

Sequence
Gp l A+ B+ Gp ll B- A-
Run/End

a0                  b1
《气动技术》双语电子教案 吴洪明
Chapter 6

   A two group building
block consists of a lever
valve to run and end the                                            Gp l
sequence plus the 5/2
double pilot operated                                 4    2
Gp ll

   For a two group system       Run/End
5   1 3       Sel ll
consisting of any number                   2
10
of cylinders this building   12
3   1
block and the cylinder        Sel l
building blocks are all
that is required to solve
the sequence
《气动技术》双语电子教案 吴洪明
Chapter 6

   This three group                         Gp l
building block
establishes an     Run/End

interconnecting
Gp ll
pattern that can
Sel l
be extended to     Sel ll
any number of
groups                                   Gp lll

Sel lll
《气动技术》双语电子教案 吴洪明
Chapter 6

Dual trip building blocks
   When a sequence has a
Send A+
cylinder operating twice in
one overall sequence a dual                                        a1 in x

trip building block may be                                         a1 in y
required for each of the two
feedback valves
   The supply will be from           A+ in                   A+ in
different groups and the          Group x                 Group y
output go to different              a1
destinations
   Example is for feedback
valve a1 of cylinder A when    Note: can often be rationalised to less
than these three components
A is sent + both in Group x
and Group y
《气动技术》双语电子教案 吴洪明
Chapter 6

   Establish the correct           Interconnect the blocks as follows:
sequence                        The first function in each group is
signalled directly by that group
   Divide the sequence in to        supply
groups. Always start a          The last trip valve operated in
sequence with the Run/End        each group is supplied with main
supply air and selects the next
valve selecting group l e.g.     group
R/E | A+ B+ | B- C+ | C- A-     The remaining trip valves are
supplied with air from their
   Select the cylinder building     respective groups and initiate the
blocks                           next function
   Select the cascade building     The “run/end” valve will control
the signal from the last trip valve
block                            to be operated
   Select dual trip building
blocks if required
《气动技术》双语电子教案 吴洪明
Chapter 6

Three position valves
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve
   5/3 valves have a third           The majority of
mid position
applications are
   The valve can be tri-
stable e.g. a detented             actuator positioning
lever operator or mono-            and safety
stable e.g. a double air or               4   2
double solenoid with          14                  12
spring centre                             5 1 3

   There are three common             14     4   2   12
configurations for the mid
position:                                 5 1 3
   All ports blocked              14             12
4   2
   Centre open exhaust
   Centre open pressure                  5 1 3
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   The valve illustrated has “all
ports blocked” in the mid
position
   Whenever the mid position is              4    2

selected the pressure
conditions in the cylinder will
be frozen                         14
5   1 3
12

   This can be used to stop the
piston at part stroke in some
positioning applications
   Flow regulators mounted close
to the cylinder to minimise
creep
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   The valve illustrated has “all
ports blocked” in the mid
position
   Whenever the mid position is             4    2

selected the pressure conditions
in the cylinder will be frozen
14
   This can be used to stop the             5   1 3
12

piston at part stroke in some
positioning applications
   Flow regulators mounted close to
the cylinder to minimise creep
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   The valve illustrated has “all
ports blocked” in the mid
position
   Whenever the mid position is              4    2

selected the pressure
conditions in the cylinder will
be frozen                         14                12
5   1 3
   This can be used to stop the
piston at part stroke in some
positioning applications
   Flow regulators mounted
close to the cylinder to
minimise creep
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   The valve illustrated has
“all ports blocked” in the
mid position
   Whenever the mid position           4    2

is selected the pressure
conditions in the cylinder
will be frozen              14
5   1 3
12

   This can be used to stop the
piston at part stroke in
some positioning
applications
   Flow regulators mounted
close to the cylinder to
minimise creep
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   The valve illustrated has “all
ports blocked” in the mid
position
   Whenever the mid position is              4    2
selected the pressure
conditions in the cylinder will
be frozen                         14                12
5   1 3
   This can be used to stop the
piston at part stroke in some
positioning applications
   Flow regulators mounted
close to the cylinder to
minimise creep
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   This version of a 5/3 valve is
“centre open exhaust”
   The supply at port 1 is
isolated and the cylinder has
power exhausted when this
14   4    2    12
centre position is selected
   The version illustrated shows         5   1 3
a mono-stable version double
pilot operated spring centre
   The cylinder will be pre-
exhausted when changing
from the mid position
《气动技术》双语电子教案 吴洪明
Chapter 6

5/3 Valve actuator control
   This version of a 5/3 valve is
“centre open pressure”
   The supply at port 1 is
connected to both sides of the
cylinder and the exhaust ports   14             12
4    2
isolated when this centre
position is selected
5   1 3
   Can be used to balance
pressures in positioning
applications
   The version illustrated is
mono-stable, double solenoid,
spring centre
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic functions for poppet and
spool valves
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                    Z
plungers X AND Y must be                           2
12        10
operated and held                     Y
3   1
   If X only is operated the air will
be blocked at port 1 in valve Y
   If Y only is operated there will be                2
12        10
no pressure available at port 1       X
3   1
   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                        Z
plungers X AND Y must be
2
operated and held                        12             10
Y
   If X only is operated the air will             3       1

be blocked at port 1 in valve Y
   If Y only is operated there will                       2
12             10
be no pressure available at port 1
X
3       1
   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                   Z
plungers X AND Y must be
2
operated and held                        12        10
Y
   If X only is operated the air will            3   1

be blocked at port 1 in valve Y
   If Y only is operated there will
2
be no pressure available at port         12        10
X
1                                             3   1

   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                        Z
plungers X AND Y must be
2
operated and held                             12             10
Y
   If X only is operated the air will             3       1

be blocked at port 1 in valve Y
   If Y only is operated there will                       2
12             10
be no pressure available at port
X
1                                              3       1

   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                   Z
plungers X AND Y must be
2
operated and held                        12           10
Y
   If X only is operated the air will        3       1

be blocked at port 1 in valve Y
   If Y only is operated there will                  2
12           10
be no pressure available at port     X
1                                         3       1

   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                      Z
plungers X AND Y must be
operated and held                           12
2
10
   If X only is operated the air      Y
3       1
will be blocked at port 1 in
valve Y
   If Y only is operated there will                     2
12             10
be no pressure available at port   X
1                                            3       1

   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   To obtain the output Z both                 Z
plungers X AND Y must be
operated and held                      12
2
10
   If X only is operated the air      Y
3   1
will be blocked at port 1 in
valve Y
   If Y only is operated there will                2
12        10
be no pressure available at        X
port 1                                      3   1

   If either X or Y is released the
output signal Z will be lost
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic AND
   This method must not be used                 Z
as a two handed safety control                   2
12        10
   It is too easy to abuse. e.g. one   Y
3   1
of the buttons could be
permanently fixed down and
the system operated from the                     2
12
other button only                                 10
X
3   1
   Use the purpose designed two
handed safety control unit
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic OR
   Use of an ‘OR’ function
shuttle valve                                   Z
   Source X and Y can be
remote from each other and
remote from the destination
of Z                                                         2
12        10
   When X or Y is operated the                     Y
shuttle valve seal moves                                 3   1
across to prevent the signal Z   12
2
10
from being lost through the X
3   1
exhaust of the other valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic OR
   Use of an ‘OR’ function
shuttle valve                                Z
   Source X and Y can be
remote from each other and
remote from the destination
of Z                                                      2
12        10
   When X or Y is operated the                 Y
shuttle valve seal moves                              3   1

across to prevent the signal   12
2
10
Z from being lost through X
3   1
the exhaust of the other
valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic OR
   Use of an ‘OR’ function
shuttle valve                                 Z
   Source X and Y can be
remote from each other and
remote from the destination
of Z
2
12
   When X or Y is operated the                                 10
Y
shuttle valve seal moves                               3   1
across to prevent the signal   12
2
10
Z from being lost through X
3   1
the exhaust of the other
valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic OR
   Use of an ‘OR’ function
shuttle valve                                     Z
   Source X and Y can be
remote from each other and
remote from the destination
of Z
2
   When X or Y is operated the                           12           10
Y
shuttle valve seal moves                                   3   1
across to prevent the signal       12
2
10
Z from being lost through      X
the exhaust of the other                3   1

valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic OR
   Use of an ‘OR’ function
shuttle valve                                       Z
   Source X and Y can be
remote from each other and
remote from the destination
of Z                                                             2
12        10
   When X or Y is operated the                         Y
shuttle valve seal moves                                     3   1
2
across to prevent the signal Z       12        10
from being lost through the      X
3   1
exhaust of the other valve
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic NOT
   A logic NOT applies to the state
of the output when the operating
signal is present (the output is
simply an inversion of the
Z
operating signal)
2
   The valve shown is a normally           12        10
open type (inlet port numbered 1)   X
1   3
   When the signal X is present
there is NOT output Z
   When X is removed output Z is
given
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic NOT
   A logic NOT applies to the state
of the output when the operating
signal is present (the output is
simply an inversion of the                   Z
operating signal)
2
   The valve shown is a normally           12           10
X
open type (inlet port numbered 1)            1   3
   When the signal X is present
there is NOT output Z
   When X is removed output Z is
given
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic NOT
   A logic NOT applies to the state
of the output when the operating
signal is present (the output is
simply an inversion of the                  Z
operating signal)
2
12
   The valve shown is a normally                    10
X
open type (inlet port numbered              1   3
1)
   When the signal X is present
there is NOT output Z
   When X is removed output Z is
given
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
   A logic MEMORY allows
the output signal state (ON or
OFF) to be maintained after
the input signal has been                      Z
removed                           X
   Any bi-stable valve is a logic        12            10
3       1
MEMORY                            Y
   With this lever detented valve,
once the lever has been
moved X direction or Y
direction it can be released
and will stay in that position
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY

   A logic MEMORY
allows the output                     Z

signal state (ON or      X
12           10
Y
OFF) to be                        3       1

maintained after the
signal that set it has
been removed
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
Z

   A bi-stable double                    12             10

pilot valve can be set                       3       1

or reset simply by a
2
pulse (push and                                      12        10
Y
release) on buttons X                                     3   1

or Y                         12
2
10
X
3    1
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
Z

   A bi-stable double                        12             10

pilot valve can be set                     3        1

or reset simply by a
2
pulse (push and                                     12         10
Y
release) on buttons X                                     3   1

or Y                         12
2
10
X
3   1
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
Z

   A bi-stable double                        12             10

pilot valve can be set                      3       1

or reset simply by a
2
pulse (push and                                     12         10
Y
release) on buttons X                                     3   1

or Y                         12
2
10
X
3   1
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
Z

   A bi-stable double                    12             10

pilot valve can be set                       3       1

or reset simply by a
2
pulse (push and                                           12       10
Y
release) on buttons X                                      3   1

or Y                         12
2
10
X
3    1
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY
Z

   A bi-stable double                    12             10

pilot valve can be set                       3       1

or reset simply by a
2
pulse (push and                                      12        10
Y
release) on buttons X                                     3   1

or Y                         12
2
10
X
3    1
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY (latch)
   A popular memory circuit is
the latch                                                    Z
   Will not re-make after          Y
1   3

pneumatic power failure             12         10
2
   A pulse on X operates the pilot                     12       10
/ spring valve to give output Z
3   1
   A feedback from Z runs
through the normally open                     2
valve Y to latch the operation      12         10
X
of Z when X is released                   3   1

   A pulse on Y breaks the latch
and Z is exhausted
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY (latch)
   A popular memory circuit is
the latch                                                          Z
   Will not re-make after           Y
1   3

pneumatic power failure              12         10
2
   A pulse on X operates the                                 12           10
pilot / spring valve to give
3   1
output Z
   A feedback from Z runs                         2
through the normally open                 12         10
X
valve Y to latch the operation             3   1
of Z when X is released
   A pulse on Y breaks the latch
and Z is exhausted
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY (latch)
   A popular memory circuit is
the latch                                                    Z
1   3
   Will not re-make after          Y
12         10
pneumatic power failure                       2

   A pulse on X operates the pilot                     12           10
/ spring valve to give output Z                          3   1
   A feedback from Z runs
through the normally open           12
2
10
valve Y to latch the operation X
3   1
of Z when X is released
   A pulse on Y breaks the latch
and Z is exhausted
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY (latch)
   A popular memory circuit is the
latch                                                        Z
1   3
   Will not re-make after          Y
12         10
pneumatic power failure                       2

   A pulse on X operates the pilot                     12       10
/ spring valve to give output Z                          3   1
   A feedback from Z runs
through the normally open           12
2
10
valve Y to latch the operation X
3   1
of Z when X is released
   A pulse on Y breaks the latch
and Z is exhausted
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic MEMORY (latch)
   A popular memory circuit is
the latch                                                     Z
1   3
   Will not re-make after           Y
12         10
pneumatic power failure                        2
   A pulse on X operates the                            12       10
pilot / spring valve to give                              3   1
output Z
   A feedback from Z runs                         2
12         10
through the normally open        X
valve Y to latch the operation             3   1

of Z when X is released
   A pulse on Y breaks the latch
and Z is exhausted
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic arrangements for fully
balanced spool valves
《气动技术》双语电子教案 吴洪明
Chapter 6

Logic circuits (spool valves)
   NO / NC                           5/2 OR
   Selection / Diversion             Single pulse control
   Latch                             Air conservation
   OR, AND, NOT                      Double flow
   Single pulse maker                Counting
   Slow pressure build
   Pre-select

Click the section to advance directly to it
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 NO / NC
   A fully balanced valve
allows pressure on any pot               2
or combination of ports         12        10

   A single valve can be used           3   1
normally open or normally
closed
   For normally open the                    2
supply pressure is connected    12        10

to port 1                            3   1
   For normally closed the
supply pressure is connected
to port 3
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 NO / NC
   A fully balanced valve allows
pressure on any pot or
2
combination of ports               12       10

   A single valve can be used          3   1
normally open or normally
closed
   For normally open the supply
2
pressure is connected to port      12       10
1                                   3   1
   For normally closed the
supply pressure is connected
to port 3
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 Valve selection / diversion
   Selection of one of two
supplies connected to           12
2
10
ports 1 and 3 can be
3   1
different pressures
   Diversion of one supply
to one of two outlets
   If it is required to exhaust         3   1

the downstream air a 5/2        12
2
10

valve is required
《气动技术》双语电子教案 吴洪明
Chapter 6

3/2 Valve selection / diversion
   Selection of one of two
supplies connected to               2
12       10
ports 1 and 3 can be
different pressures             3   1

   Diversion of one supply
to one of two outlets
   If it is required to exhaust    3   1
the downstream air a 5/2       12       10
2
valve is required
《气动技术》双语电子教案 吴洪明
Chapter 6

Latch with controls
Out
   In this version of a latch
2
the push button valves are                     12        10
connected to perform ‘OR’                           3   1
and ‘NOT’ functions
   The ‘OFF’ valve must be      ON   12
2
10
placed last in the signal              3   1
chain so that if both
valves are operated                        2
together the ‘OFF’           OFF 12         10

command will dominate                  3   1
over the ‘ON’ command
《气动技术》双语电子教案 吴洪明
Chapter 6

OR, AND, NOT                                  z   2
OR    12            10
   A single 3/2 pilot                    3       1
operated spring return
valve can be use for any   x          y
z
of these logic functions   AND   12
2
10

   x OR y gives output z                 3       1
x                  y
   x AND y gives output z
z   2
NOT
   x gives NOT z                    12            10

3       1
x
《气动技术》双语电子教案 吴洪明
Chapter 6

Single pulse maker
   Converts a prolonged
signal x into a single                    z
pulse z                                       2
12            10
   Signal z must be removed
3       1
to allow the valve to reset
then x can be applied
again
   The duration of the pulse             x
flow regulator
《气动技术》双语电子教案 吴洪明
Chapter 6

Slow initial pressure build up
   Choose a 3/2 pilot spring
valve with a relatively high
2
operating force e.g. 3 to 4         12        10
bar                                      3   1
   When the quick connect
at port 2 is controlled at the
rate of the flow regulator
setting
   When the pressure is high
enough to operate the valve
full flow will take over
《气动技术》双语电子教案 吴洪明
Chapter 6

Pre-select
   The lever valve can pre-
select the movement of
the cylinder OUT or IN                                    2
12        10
   The movement will occur
the next time the plunger                             3   1

valve is operated                 12
2
10
   The plunger valve can be                 3   1
released immediately and
subsequently operated                        2
10
and released any number      12
of times                    OUT/IN
3   1
pre-select
《气动技术》双语电子教案 吴洪明
Chapter 6

5/2 OR function
   The valve at position ‘a’ is
reversed connected and
supplied from the valve                 4    2
12
conventionally connected       a   14

at position ‘b’                         5   1 3

   The cylinder can be
4    2
controlled from either                            12
b   14
position ‘a’ ‘OR’ position
5   1 3
‘b’
《气动技术》双语电子教案 吴洪明
Chapter 6

Single pulse control
   Each time the foot
operated valve is
pressed the cylinder
will single stroke +                             4       2
12
and - alternately                           14

   First foot operation                             5   1

the cylinder moves                      2                          2
12          10              12            10
out
3     1                     3    1
   Second foot operation
the cylinder moves in
   Third….. out and so
on
12        2
10

3   1
《气动技术》双语电子教案 吴洪明
Chapter 6

Air conservation
   Power stroke in the instroke
direction only
   Differential area of the piston
gives an outstroke force when
the pressure is balanced
4       2
   Air used to outstroke is                           12
14
equivalent to a cylinder with
5   1
only the same bore as the rod
diameter
   Assumes the cylinder is not
loaded on the plus stroke and
low friction
《气动技术》双语电子教案 吴洪明
Chapter 6

Air conservation
   Power stroke in the instroke
direction only
   Differential area of the
piston gives an outstroke
force when the pressure is
balanced                               4       2
12
14
   Air used to outstroke is
equivalent to a cylinder           5       1

with only the same bore as
the rod diameter
   Assumes the cylinder is not
and low friction
《气动技术》双语电子教案 吴洪明
Chapter 6

Double flow
   Where a larger 3/2 valve
is not available
   Two flow paths in a 5/2
valve each with a
separate supply can be             4     2
arranged to give double     14               12
flow or supply separate            5 1   3
devices
   Ensure the tube size to
the cylinder is large
enough to take the double
flow
《气动技术》双语电子教案 吴洪明
Chapter 6

Double flow
   Where a larger 3/2 valve
is not available
   Two flow paths in a 5/2
valve each with a
separate supply can be
4    2
arranged to give double      14         12
flow or supply separate
5 1   3
devices
   Ensure the tube size to
the cylinder is large
enough to take the double
flow
《气动技术》双语电子教案 吴洪明
Chapter 6

Counting                              4
   Counting applications are best
achieved with electro-
mechanical or programmable        3
electronic counters
   Pneumatic counting circuits use
large numbers of logic valves
2
and can be slow
   The counting chain shown will
count to 4
1
   Red and blue are non-
overlapping alternate pulses,
purple is the reset line
《气动技术》双语电子教案 吴洪明
Chapter 6

Counting application                                       a0   a1
A
   The counting circuit is applied
to count 4 strokes of a cylinder
   At rest all counting valves are
held reset by the start valve
   Start outstrokes ‘A’
   Alternate signals from ‘a1’ and
‘a0’ progresses operation of the
counting valves up the chain
   On the 4th operation of ‘a1’ the               Start

green signal resets the start
valve to stop the cylinder
a1     a0
《气动技术》双语电子教案 吴洪明
Chapter 6

Feedback methods
《气动技术》双语电子教案 吴洪明
Chapter 6

Time delay
   A signal is restricted to
slow the rate of pressure
build up on a pressure                      Output
switch (3/2 differential
pressure operated valve)                          2
12             10
   When the pressure switch
3 1
operates a strong un-
restricted output is given
   A reservoir provides
Signal
capacitance to allow less       in
fine and sensitive settings
on the flow regulator
《气动技术》双语电子教案 吴洪明
Chapter 6

Time delay
-        +
   Manual remote start                                                     a1

A
of a double acting
cylinder with a time
delay in the                                        4    2
outstroked position                    14                    12

before automatic                                    5   1 3

2
return                                                       12              10

3 1
2                  2
12           10   12         10

3       1    a1   3    1
《气动技术》双语电子教案 吴洪明
Chapter 6

Pressure decay
   Manual remote start of a                         -        +                a1
double acting cylinder
A
   Uses a low pressure
operated valve connected
normally open
4    2
   When the back pressure in            14                       12
the front of the cylinder                            5   1 3
falls below 0.1 bar the
return signal is given
2                             2
   Connection taken between    12            10               10          12
the cylinder and flow            3       1                         1   3   0.1bar
regulator
   Useful for pressing work
pieces of variable size
《气动技术》双语电子教案 吴洪明
Chapter 6

Electro-pneumatic
   The majority of systems use          Circuit building block for
electrical/electronic control         each cylinder
due to the high degree of
a0    a1
sophistication and flexibility
   Solenoid valves are used to                A
control cylinders
   Feedback signals are from
reed switches, sensors and                     4     2
electrical limit switches             14              12

   Logic is hard wired or                         5    1 3
programmed in to a PLC
(programmable logic
a0                 a1
controller)
《气动技术》双语电子教案 吴洪明
Chapter 6

End

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