U.S. patent application number 10/398619 was filed with the patent office on 2004-01-22 for arrangement using fluid technology and valve arrangement and actuator for the same.
Invention is credited to Aichele, Alexander, Lederer, Thomas, Ziegele, Achim.
Application Number | 20040011194 10/398619 |
Document ID | / |
Family ID | 7659151 |
Filed Date | 2004-01-22 |
United States Patent
Application |
20040011194 |
Kind Code |
A1 |
Lederer, Thomas ; et
al. |
January 22, 2004 |
Arrangement using fluid technology and valve arrangement and
actuator for the same
Abstract
A fluid power arrangement and valve arrangement (12) with an
actuator (10) for it. The actuator (10) is able to be operate by
means of the valve arrangement (12) via at least one first and
first second fluid line (13 and 14) using fluid power, at least one
electrical component (37, 38 and 46), adapted for connection with a
control module (39 and 61), being arranged on the actuator (10). In
this case there is a provision such that the valve arrangement (12)
and the actuator (10) are connected together by way of two
electrical connections (28 and 29) included in the fluid lines (13
and 14), by way of which fluid lines the valve arrangement (12)
supplies the actuator (10) with electrical energy and furthermore
the actuator (10) and the valve arrangement (12) are provided
respectively with signal producing and/or signal detecting means
(41 and 44) for establishing an signal connection (SV) between the
at least one electrical component (37,38 and 39) and the control
module (39 and 61) by way of and the second electrical connection
(28 and 29).
Inventors: |
Lederer, Thomas; (Kernen,
DE) ; Ziegele, Achim; (Uhingen-Baierek, DE) ;
Aichele, Alexander; (Osfildern, DE) |
Correspondence
Address: |
Charles R Hoffmann
Hoffmann & Baron
6900 Jericho Turnpike
Syosset
NY
11791
US
|
Family ID: |
7659151 |
Appl. No.: |
10/398619 |
Filed: |
April 7, 2003 |
PCT Filed: |
October 2, 2001 |
PCT NO: |
PCT/EP01/11378 |
Current U.S.
Class: |
92/5R |
Current CPC
Class: |
F15B 13/0867 20130101;
F15B 9/09 20130101; F15B 21/08 20130101 |
Class at
Publication: |
92/5.00R |
International
Class: |
F01B 025/26 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2000 |
DE |
100 49 958.9 |
Claims
1. A fluid power arrangement comprising at least one fluid power
actuator (10), which may be operated by means of a valve
arrangement (12) via at least one first and one second fluid line
(13 and 14) using fluid power, at least one electrical component
(37, 38 and 46) being provided on the actuator (10) for connection
with a control module (39 and 61), characterized in that the valve
arrangement (12) and the actuator (10) are connected together by
way of a first and a second electrical connection (28 and 29), by
way of which electrical connection the valve arrangement (12)
supplies the actuator (10) with electrical energy by the provision
of a voltage (UV), the first electrical connection (28) being by
way of the first fluid line (13) and the second electrical
connection (29) being by way of the second fluid line (14) or by
way of a joint ground potential (MP) between the actuator (10) and
the valve arrangement (12) and the actuator (10) and the valve
arrangement (12) are respectively provided with signal producing
and/or signal detecting means (41 and 44) for establishing a signal
connection (SV) between the at least one electrical component (37,
38 and 46) and the control module (39 and 61) by way of the first
and the second electrical connection (28 and 29).
2. The fluid power arrangement as set forth in claim 1,
characterized in that at least one electrical component is a sensor
(37 and 38) responsive to at least one operational state of the
actuator (10).
3. The fluid power arrangement as set forth in claim 1 or in claim
2, characterized in that the signal producing and/or signal
detecting means (41) of the actuator (10) as communication module
comprise a modulator for modulating the voltage (UV) with
monitoring signals and in that signal producing and/or signal
detecting means (44) associated with the valve arrangement (12)
comprise a demodulator for getting the monitoring signal from the
voltage (UV).
4. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that at least one electrical
component is an electrical drive member and/or a display element
(46).
5. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the signal producing and/or
signal detecting means (44) associated with the valve arrangement
(12) comprise, as communication means, a modulator for the supply
of control signals by modulation of the voltage (UV) and in that
the signal producing and/or signal detecting means (41) of the
actuator (10) comprise a demodulator for de modulation of the
control signals from the voltage (UV).
6. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the signal producing and/or
signal detecting means (44) associated with the valve arrangement
(12) constitute a component of the valve arrangement (12).
7. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the signal producing and/or
signal detecting means (41 and 44) associated with the valve
arrangement (12) comprise a bus interface for communication between
the valve arrangement (12) and the control module (39 and 61).
8. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the actuator (10) and/or
the valve arrangement (12) include connection means (15, 16, 17 and
18) adapted for the connection of the first and/or second fluid
line (13 and 14) and more particularly designed in the form of plug
connection means, in the case of which connection means both a
fluid power and also an electrical connection (28 and 29) is
produced preferably using a single manipulation.
9. The fluid power arrangement as set forth in any one of the
preceding claim, characterized in that the valve arrangement (12)
includes at least one valve (19) and in that the first and/or the
second fluid line (13 and 14) are directly connected with the at
least one valve (19) and/or the ducts (20 and 21), leading to the
valve (19), of the valve arrangement (12).
10. The fluid power arrangement as set forth in claim 9,
characterized in that the signal producing and/or signal detecting
means (41 and 44) associated with the valve arrangement (12) are
provided on the valve or valves (19).
11. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the valve arrangement (12)
includes a single valve or a multiple valve arrangement.
12. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the first and/or the second
fluid line (13 and 14) are designed in the form of flexible hose
lines.
13. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the valve arrangement is
preferably made up of modules (11a and 11b) constituting a valve
cluster (60).
14. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the control module (39)
constitutes a component of the valve arrangement (12).
15. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the first and/or second
fluid line (13 and 14) are arranged in a pair on a common side of
the actuator (10).
16. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the at least one electrical
component (37, 38 and 39) communicates by a wireless connection
with the signal producing and/or signal detecting means (41 and 44)
of the actuator (10).
17. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the valve arrangement (12)
and the actuator (10) transmit data along the signal connection
(SV) serially and more particularly with the aid of a field bus
protocol or some other digital signal sequence.
18. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that the first and/or the second
fluid line (13 and 14) respectively comprise only one single
electrical conductor (28 and 29).
19. The fluid power arrangement as set forth in any one of the
preceding claims, characterized in that for signal production the
signal producing means (41 and 44) set a different, preferably
impressed current flow on the signal connection (SV).
20. The fluid power arrangement as set forth in claim 19,
characterized in that the signal producing means (41 and 44)
comprises a triac and/or a transistor and/or a resistor with a
predetermined current flow conducting potential.
21. An actuator for a fluid power arrangement, which by means of a
valve arrangement (12) by way of at least one first and one second
fluid line (13 and 14) is able to be operated by fluid power, on
which at least one electrical component (37, 38 and 46), provided
for connection with a control module (39 and 61), is arranged,
characterized in that the actuator (10) comprises connection means
(17 and 18) for a first and a second electrical connection (28 and
29), by way of which said actuator (10) may be supplied with
electrical energy by the provision of a voltage (UV), the first
electrical connection (28) being included in the first fluid line
(13) and the second electrical connection (29 being included in the
second fluid line (14) or by way of a ground potential (MP), and in
that the actuator (10) comprises signal producing and/or signal
detecting means (41) for establishing a signal connection (SV)
between the at least one electrical component (37, 38 and 41) and
the control module (39 and 61) by way of the first and the second
electrical connection (28 and 29).
22. A valve arrangement for a fluid power arrangement comprising at
least one fluid power actuator (10) which by means of the valve
arrangement (12) is able to be operated by way of at least one
first and one second fluid line (13 and 14) using fluid power and
on which at least one electrical component (37, 38 and 46) is
arranged, said component being provided for connection with a
control module (39 and 61), characterized in that the valve
arrangement (12) includes connection means (15 and 16) for a first
and a second electrical connection (28 and 29) with the actuator
(10), by way of which the valve arrangement (12) may supply the
actuator (10) with electrical energy by the provision of a voltage
(UV), the first electrical connection (28) being included in the
first fluid line (13) and the second electrical connection (29
being included in the second fluid line (14) or being by way of a
common ground potential (MP) between the actuator (10) and the
valve arrangement (12) and in that the valve arrangement (12) has
signal producing and/or signal detecting means (44) for the
establishment of a signal connection (SV) between the at least one
electrical component (37, 38 and 46) and the control module (39 and
61) by way of and the second electrical connection (28 and 29).
Description
[0001] The present invention relates to a fluid power arrangement
comprising at least one fluid power actuator, which may be operated
by means of a valve arrangement via at least a first and second
fluid line using fluid power, at least one electrical component
being provided on the actuator for connection with a control
module. Furthermore, the invention relates to an actuator and a
valve arrangement each for a fluid power arrangement of this
type.
[0002] Such a fluid power arrangement is for instance disclosed in
the German patent publication 198,827,833 A1. In this case
so-called double-acting cylinder are illustrated as actuators,
whose pistons are able to be moved in two opposite directions and
are each able to be driven into a terminal position. The cylinders
are operated by compressed air supplied through a pair of
compressed air lines joined with the piston rod gland end and at
the opposite end from a valve arrangement. For operation of the
cylinders valves arranged in the valve arrangement cause the supply
of pressure medium or venting of the cylinder chambers. Using
sensors the respective piston position in the cylinders is detected
and by way of separate electrical connection lines such position is
communicated to a control device.
[0003] In the case of this conventional fluid power arrangement in
each case two compressed air lines and also two electrical
connection lines must be connected with each cylinder. The amount
of wiring and hose configuration work is therefore substantial.
[0004] There has already been a suggestion to solve this problem in
the said German patent publication 198,827,833 A1 by arranging the
valves for each cylinder directly on the cylinders and having only
one compressed air supply line extending to the cylinder.
Furthermore there is a suggestion to provide the compressed air
supply line with a plurality of electrical lines, which partly
serve for electrical power supply to the electrical components of
the cylinder and partly for the transmission of data between the
control device and also the valves and sensors.
[0005] There is admittedly on the one hand a reduction in the
amount of fluid line required with this design. However, on the
other hand expensive and complexly arranged flexible compressed air
lines having several electrical conductors are necessary, which in
addition make necessary complex connections for joining the
compressed air lines with the cylinders and also the compressed air
supply system.
[0006] Accordingly one object of the invention is to provide a
straightforward and readily handled, economic fluid power
arrangement. Furthermore, a valve arrangement and an actuator are
proposed, which are more especially suitable for such a fluid power
arrangement.
[0007] This object is to be achieved using a fluid power
arrangement of the type initially mentioned, in the case of which
the valve arrangement and the actuator are connected together by
way of a first and a second electrical connection, by way of which
the valve arrangement supplies the actuator with electrical energy
by the provision of a voltage, the first electrical connection
being by way of the first fluid line and the second electrical
connection being by way of the second fluid line or by way of a
joint ground potential between the actuator and the valve
arrangement and the actuator and the valve arrangement are
respectively provided with signal producing and or signal detecting
means for establishing a signal connection between the at least one
electrical component and the control module by way of the first and
the second electrical connection.
[0008] In order to attain the object of the valve there is
furthermore the provision of an actuator in accordance with
technical teaching of claim 18 and a valve arrangement in
accordance with technical teaching of claim 19,
[0009] The principle of the invention is to form a current circuit
between the actuator and the valve arrangement, by way of which
circuit the actuator is on the one hand supplied with electrical
energy and on the other hand an electrical signal connection is
produced between the electrical component or components of the
actuator and the control module. In this case a first fluid line
leading to the actuator, as for example a compressed air or
hydraulic line, is utilized not only for the supply and removal of
fluid, but also as an electrical connection line between the valve
arrangement and the actuator. The fluid line is for this purpose
electrically conductive or is provided with an electrical
conductor.
[0010] The current circuit between the actuator and the valve
arrangement is, in a preferred embodiment, connected by way of a
second electrically conductive fluid line.
[0011] In accordance with a further embodiment the second
electrically conductive fluid line is not necessary. Instead of it
the combined energy and signal current circuit between the actuator
and the valve arrangement is completed by way of a common ground
potential between the actuator and the valve arrangement.
[0012] In any case the energy supply and signal transmission are by
way of a single, common current circuit, for which no electrical
lines separate from the fluid lines are necessary. In this case the
complexity of manufacture is reduced as well, since the fluid lines
do not have to be fitted with a plurality of electrical conductors,
and in fact only have one single electrical conductor. The actuator
may furthermore be made compact, since valves employed for its
operation may be arranged remote from it on the valve arrangement.
Furthermore, the control module may, if it has a suitable
diagnostic means, diagnose the interruption of one of the fluid
lines on the basis of the interruption of the respective electrical
connection with the respective fluid line.
[0013] Further advantageous developments of the invention are
recited in the dependent claims and in the specification.
[0014] For signal transmission in the monitoring direction from the
actuator to the control module the signal producing and/or signal
detecting means of the actuator preferably comprise, as
communication means, a modulator for modulating the voltage with
monitoring signals and on the other hand the signal producing
and/or signal detecting means, (which are associated with the valve
arrangement) comprise as a communication means a demodulator for
demodulating the voltage to get the monitoring the signals from the
voltage. The modulator and the demodulator transmit serially
digitally encoded pulse sequences.
[0015] For the control of the actuator by the control module in the
control direction the signal producing means, associated with the
valve arrangement, comprise as communication means a modulator for
the supply of control signals by modulation of the voltage. The
signal detection means of the actuator then use a demodulator to
recover the control signals from the voltage. Furthermore, the
modulator-demodulator combination also transmits serially digitally
encoded pulse sequences.
[0016] The signal producing and/or signal detecting means
associated with the valve arrangement preferably form a component
of the valve arrangement. They may however in principle be a
component of, for example, the control module or a bus node of a
field bus, which is provided between the valve arrangement and the
control module.
[0017] It is an advantage for the signal producing and/or signal
detecting means associated with the valve arrangement to include a
bus interface provided for communication between the valve
arrangement and the control module.
[0018] The assembly of the fluid power arrangement is facilitated
as regards the actuator and/or the valve arrangement by having
connection means more particularly in the form of plug connection
means, in the case of which in a single manipulation both a fluid
power and also an electrical connection is advantageously produced.
For this purpose it is for example suitable to employ an
electrically conductive screw or plug connection for the fluid
line.
[0019] Preferably, the first and/or the second fluid lines only
have just one single electrical conductor, which may be designed in
different ways. A fluid line in the form of a flexible hose may for
instance be provided with only one electrically conductive wire
braid structure or with an electrically conductive foil. A rigid
fluid line, as for example a metal tube, may as such serve as an
electrical conductor and is, if necessary, externally provided with
electrical insulation.
[0020] In accordance with a preferred modification of the invention
the signal producing means impress, for signal production, a
current flow on the signal connection. For this purpose transistor
circuits are suitable as signal production means or more preferably
furthermore diodes, which respectively only permit a predetermined
current flow. The signal detection means then ascertain the
respective current flow, for example with a shunt resistor and may
in this manner comprise signals from the at least one electrical
component. It is then extremely simple to attain a current flow for
signal production also using one or more resistors having different
resistance values.
[0021] In the following the invention and its advantages will be
described with reference to working examples as illustrated in the
accompanying drawings.
[0022] FIG. 1 shows a first working embodiment of a fluid power
arrangement in accordance with the invention with an actuator which
is connected by way of two fluid lines each with a respective
additional electrical conductor with a valve arrangement.
[0023] FIG. 2 represents a further development of the working
example of FIG. 1 with a further actuator and a further valve
arrangement.
[0024] FIG. 3 shows a modification of the working embodiment of
FIG. 1 in the case of which an electrical connection is provided
between the valve arrangement and the actuator using a common
ground potential.
[0025] FIG. 4 is a diagrammatic view of a modification of the
working example of FIG. 1 in the case of which the signal producing
means of the actuator set impressed current flows on the signal
connection with the valve arrangement.
[0026] FIG. 1 diagrammatically shows a fluid power arrangement,
which is in the present case electro-pneumatic, having an actuator
10, which as a drive element has a cylinder 11. The actuator 10 may
also comprise a different type of fluid operated drive, as for
example a rotary drive or piston rod-less linear drive. The
cylinder 11 is able to be operated using a valve arrangement 12
controlling the flow of compressed air, a piston 27 in the cylinder
11 being reciprocated in a cylinder chamber 9. For the actuation of
the cylinder 11 using compressed air compressed air lines 13 and 14
are arranged between the valve arrangement 12 and the actuator 10,
such lines being for example in the form of flexible hose lines or
rigid metal tubes. The compressed air lines 13 and 14 are connected
by way of connection means 15 and 16, which constitute connection
means, with the valve arrangement 12 and by way of connections 17
and 18 are connected with the actuator 10. In the present case the
connections 17 and 18 arranged in pairs on a common side of the
actuator 10, although they may be in principle arranged on opposite
sides, for example. The connections 15 through 18 may for example
be plug connections or screw connections.
[0027] In the valve arrangement 12 compressed air ducts 20 and 21
lead from the connections 15 and, respectively, 16 to a valve 19,
which controls pressurization or venting of the compressed air
lines 13 and 14. A compressed air supply means, not illustrated,
for example in the form of compressed air producing device and a
servicing device, supplies the valve 19 with compressed air. The
valve 19 is connected by way of a compressed air supply
distribution system, only represented by one compressed air supply
line 22 with the compressed air supply means. The valve 19
constitutes an integral component of the valve arrangement 12 or it
is a replaceable separate valve able to be arranged on the valve
arrangement 12, for example by plugging in place. In addition to
the valve 19 the valve arrangement 12 may comprise further valve,
not illustrated.
[0028] In the actuator 10 a compressed air duct 23 leads from the
connection 17 to a cylinder space 24, in the end plate head of the
cylinder, of the cylinder chamber 9 and a compressed air duct 25
runs to the piston rod gland end cylinder space of cylinder
chamber. When the valve 19 pressurizes the compressed air line 13
with compressed air and at the same time vents the compressed air
line 14, the piston 27 of the cylinder 11 will be moved toward
cylinder space 26 in the cylinder head. The piston 27 will move
toward the space 24 when the valve 19 pressurizes the cylinder
space 26 in the cylinder head by way of the compressed air line 14
and vents the compressed air line 13.
[0029] The valve arrangement 12 and the actuator 10 are connected
with one another by way of connecting lines 28 and 29, which extend
in or on the compressed air lines 13 and 14 and for instance are
constitute by a wire braid structure, or metal foil, embedded in a
casing of the compressed air lines 13 and 14 or extending on same.
Furthermore, as an electrical conductor in the compressed air lines
13 and 14 furthermore one or more metal multi-strand wires or
cables may be provided. The electrical contact between the
connecting lines 28 and 29 and the actuator 10 and furthermore the
valve arrangement 12 is produced by way of connections 15 through
18, which in the present case consist of metal and accordingly are
electrically conductive. The connections 15 through 18 are in
electrical contact with the compressed air lines 13 and 14, such
contact being produced f. i. by knife contact elements, which cut
into the compressed air lines 13 and 14.
[0030] During assembly of the connections 15 through 18, for
example by screwing or plugging into one another, in the present
case a single manipulation produces both a fluid and also an
electrical connection between the valve arrangement 12 and the
actuator 10. In principle it would be possible to provide separate
electrical contact elements, separate from the connections 15
through 18, and independent from the respective fluid power
connection for connection of the electrical connection lines 28 and
29 with the valve arrangement 12 and, respectively, the actuator
10.
[0031] The valve arrangement 12 possesses an electrical energy
source 30, which by way of electrical connections 31 and 32 and by
way of the connections 15 and 16 is connected with the electrical
connection lines 28 and 29. The energy source may for example be
one member of a voltage converting component group which is
supplied from an external voltage source, not illustrated. The
energy or power source 30 provides a voltage UV for the actuator 10
by way of the electrical connection lines 28 and 29.
[0032] For using the voltage UV the actuator 10 possesses an energy
converter 33, which by way of electrical connections 34 and 35 and
by way of the connections 17 and 18 is connected with the
electrical connection lines 28 and 29. The energy converter 33
converts the voltage UV, for example with the aid of an electronic
circuit and/or an electrical transformer, a rectifier and a
smoothing capacitor and supplies a current distribution system 36,
only indicated by a positive potential and a negative potential, of
the actuator 10.
[0033] On the actuator 10 sensors 37 and, respectively, 38 designed
in the form of electrical components, are provided, which are
associated with the respective cylinder spaces 24 and 26. The
sensors 37 and 38 detect an operational state of the actuator 10 in
the present case the position of the piston 27, and indicate this
to a control module 39, which controls the valve arrangement 12 and
the actuator 10. The sensors 37 and 38 are f. i. limit switches
actuated by the piston 27. The sensors 37 and 38 may however f. i.
also be sensors operating ultrasonically which as components of a
displacement measuring system ascertain the position of the piston
27. On the actuator 10 it would be possible for instance to also
provide temperature sensors, pressure sensors or other sensors for
detecting a regular operational state and/or a trouble state.
[0034] The actuator 10 supplies values ascertained by the sensors
37 and 38 to the control module 39, which in the working embodiment
of FIG. 1 constitutes a component of the valve arrangement 12. The
control module 39 comprises for instance microprocessor, memory
means and an input/output interface. The control module 39
functions in accordance with a pre-programmed functional profile,
which is set by a program code stored in the memory means and by
way of a control connection 48 controls the valve 19 and
accordingly the actuator 10. The control module 39 could also be an
analog and/or digital regulating circuit. The control module 39 can
receive instructions from a control console, not illustrated,
and/or a central master control, not illustrated.
[0035] The values detected by the sensors are supplied to the
control module 39 by way of a signal connection SV indicated in
chained lines, contained in the electrical connection lines 28 and
29. For the production of the signal connection SV a communication
module 41 is provided in the actuator 10 as a signal producing
and/or signal detecting means, such communication module serving as
a communication means and being coupled to the connections 34 and
35, for example using an electrical transmitter. Accordingly it is
connected with the electrical connection lines 28 and 29. The
communication module 41 receives data, detected by the sensors 37
and 38, by way of connections 42 and 43. The same are employed by
the communication module 41 as monitoring signals with the aid of a
modulator for modulation of the voltage UV. For this purpose pulse
width, pulse frequency or some other modulation method is utilized.
It is also possible for the communication module 41 to digitally
encode the monitoring signals using an encoding means and to
transmit same as serial data telegrams to the valve arrangement 12.
For this purpose a field bus protocol can for example be
utilized.
[0036] For receiving the monitoring signals on the signal
connection SV the valve arrangement 12 comprises a communication
module 44 which is coupled with the connections 31 and 32, for
example by way of a shunt resistor connected in series with the
energy source 30 and spies on, as it were, the modulated and/or
encoded monitoring signal transmitted by way of the electrical
connections 28 and 29 and with the aid of a demodulator and/or
decoder detects the voltage UV. The communication module 42
transmits the monitoring signals by way of a connection 45 to the
control module 39 with the result that in all the signal connection
SV is produced between the sensors 37 and 38 and the control module
39.
[0037] The control module 39 controls the valve 19 in a manner
dependent on the respective monitoring signals from the sensors 37
and 38, which contain information about the position of the piston
27. In this case the cylinder space 26 is for example only
pressurized with compressed air until the sensor 37 indicates that
the piston 27 has reached its terminal position in the cylinder
head.
[0038] The actuator 10 in the working example possesses as a
further electrical component a display element 46. The display
element 46 comprises for example LED's and/or a LCD display module
for displaying the current operational states, for instance the
current position of the piston 27 and/or to indicate trouble
conditions, for example when a component of the actuator 10 is
defective or has completely failed.
[0039] The display element 46 is connected by way of an electrical
connection 47 with the communication module 41 and via same
receives control instructions from the control module 39. Using a
modulator the communication module 44 then modulates the voltage UV
with control signals which are recovered again by the communication
module 41 by means of a demodulator. The modulator is for example
coupled by means of an electrical transmitter with an electrical
connections 31 and 32. The demodulator scans, for example using a
resistor connected in series with the energy converter 33, the
voltage changes caused by the control signals with which the
voltage UV is modulated.
[0040] In principle the modulator in the communication module 44
could also modulate the voltage UV, and for example by switching on
and off the voltage UV could form a digital pulse sequence.
[0041] The actuator 10 could as an electrical component also
possess an electrical drive means, controlled by the control module
39, as for example an electromagnetic drive or a drive motor.
Furthermore, operating elements could be provided on the actuator
10, as for instance an "emergency off" switch, which send
instructions of an operator by way of the communication module 42
and the electrical connection lines 28 and 29 to the control module
39.
[0042] FIG. 2 shows valve arrangements 12a and 12b, which are
connected with actuators 10a and 10b, respectively, by way of
compressed air lines 13a, 14a and, respectively, 13b and 14b. The
valve arrangements 12a and 12b are modules of a valve cluster 60,
which is supplied with compressed air by way of the compressed air
supply line 22 illustrated in FIG. 1, and is controlled by a
central control module 61 by way of a bus 63, for example an AS-i
field bus (AS-i denoting actuator sensor interface). The bus 63 and
furthermore the compressed air supply line 22 symbolically
representing a compressed air distribution system, not illustrated,
are extended through the valve arrangements 12a and 12b so that
further valve arrangements, in the form of modules and not
illustrated to make the figure more straightforward, can be lined
up on the valve cluster 60. The control module 61 can constitute a
separate control device or form a component of the valve cluster
60.
[0043] The actuators 10a and 10b are essentially the same in
structure as the actuator 10 in accordance with FIG. 1, but however
lack the display element 46. Moreover the valve arrangements 12a
and 12b are essentially the same in structure as the valve
arrangement 12. Identical or identically functioning components are
therefore in FIG. 2 provided with the same reference numerals as
the corresponding component in FIG. 1, added small case letters "a"
and "b" indicating an association of the respective component with
the actuator valve arrangement combinations 10, 12a and,
respectively, 10, 12b.
[0044] In contradistinction to the valve arrangement 12 the valve
arrangements 12a and 12b however lack any separate control module
of their own and instead of this are connected by way of bus
interface modules 64a and 64b with the field bus 63 and are
controlled via same by the control module 61. The bus interface
modules 64a and 64b and the communication modules 44a and 44b
respectively associated with them can be respectively put in a
component group, for example an IC.
[0045] FIG. 3 essentially shows the arrangement in accordance with
FIG. 1. In contradistinction to FIG. 1 however only one electrical
connection is provided between the valve arrangement 12 and the
actuator 10 by way of an electrically conductive compressed air
line, namely the compressed air line 13. The second electrical
connection between the valve arrangement 12 and the actuator 10 is
by way of common ground potential MP, for example a common
grounding means, to the electrically conductive connections 16 and
19 in each case. It is also possible for the housing of the
actuator 10 and the valve arrangement 12 to be respectively
connected with the ground potential MP with the result that the
second electrical connection is made. In a fluid connecting
compressed air line 14c joining the connections 16 and 18
consequently, unlike the compressed air line 14, no electrical line
is required.
[0046] It is also possible for the actuators 10a and 10b to only
have controlled electrical components, as for example electrical
drive members, or only monitoring components, as for instance
sensors.
[0047] A particularly simple and merely diagrammatically
illustrated modification of the working example in accordance with
FIG. 1 is depicted in FIG. 4, in the case of which signal producing
means of the actuator set impressed current flows on the signal
connection leading to the valve arrangement. However, for
simplification of the drawing only a few components of the actuator
10 and of the valve arrangement 12 are depicted. The energy source
30 of the valve arrangement 12 supplies by way of the electrical
connections 28 and 29 (which are by way of the compressed air line
13 and 14) the actuator 10 with the voltage UV, which drops at the
sensors 37 and 38 connected in parallel with the electrical
connections 34 and 35, and at current sources 50 and 51
respectively connected in series therewith, such current sources
serving as signal producing means. The sensors 37 and 38 are for
example reed switches, magnetostrictive elements or hall sensors,
which become electrically conductive in the proximity of the piston
27 and are otherwise non-conductive or have a low conductivity. The
current sources 50 and 51 are so-called current flow setting diodes
which in their conductive direction are conductive as far as a
predetermined current flow, that is to say they set an impressed
current flow. It is also possible for the current sources 50 and 51
to be constituted by transistor circuits, which set an impressed
current flow or for the sensors 37 and 38 to inherently set current
flows impressed by their respective resistance value and
accordingly as such constitute the signal producing means of the
actuator 10.
[0048] When the sensors 37 and 38, owing to the proximity of the
piston 27, become electrically conductive, they will carry current
flow, which is set by the current sources 50 and 51 respectively
set as the impressed current I37 and, respectively, I38. The values
of the current flows I37 and I38 have different levels so that an
overall current flow Iges flowing the electrical connections 28 and
29 is set with the values Iges=0, Iges=I37, Iges=I38 or, more
particularly in the case of a fault, Iges=I 37+I38. The level of
the overall current Iges is accordingly a signal determined by the
signal producing means of the actuator 10 for the respective
position of the piston 27.
[0049] In the valve arrangement 12 there is a shunt resistor 52,
which is connected in series with the energy source 30 and
associated with the signal detection means of the valve arrangement
12 having a resistance R, a so-called shunt, which has the overall
current Iges flowing through it and at which, in accordance with
the overall current Iges, a voltage Um drops with the values Um=0,
Um R * I37, Um R * I38 or Um R * (I37+I38). The level of the
voltage Um is scanned and evaluated using signal detection means
not illustrated in detail.
[0050] It will be clear that the principle indicated in FIG. 4, in
the case of which the impressed current flows are set, may also be
employed in the reverse direction for supplying a signal from the
valve arrangement 12 to the actuator 10.
[0051] Furthermore as a signal producing means instead of the
current sources 50 and 51 or in addition thereto a respective
resistor could be provided, such resistors preferably having
different resistance values. Moreover, the sensors 37 and 38 could
respectively produce different resistance values, for instance
owing to the proximity of the piston 27 in the electrically
connecting state with the result that the sensors 37 and 38 could
serve as signal producing means.
[0052] Further designs are readily possible.
[0053] To the extent that an actuator only comprises monitoring
electrical components, only transmitting means, as for example a
modulator will be necessary in its communication module, as for
example a modulator, and in the valve arrangement associated with
the actuator or in the control module associated with it only
receiving means, as for example a demodulator, will be
necessary.
[0054] If an actuator only contains controlled electrical
components and no monitoring ones, then in the communication module
associated with the actuator only a transmitting means, as for
example a modulator, and in the actuator only a receiving means, as
for example a demodulator, will be necessary.
[0055] If however an actuator and a valve arrangement communicate
bi-directionally, as for instance using a field bus protocol, then
in their respective communication modules both transmitting and
also receiving means will be required independently of whether the
respective actuator has only controlled or only monitoring
electrical components. By way of a bi-directional connection the
respective control module can control information flow and for
instance perform diagnosistic interrogation on the actuator.
[0056] In accordance with a modification of the arrangement of FIG.
2 the communication modules 44a and 44b and furthermore the energy
sources 30 are not integrated in the valve arrangements 12a and
arrangements 12b and instead constitute a component of the control
module 61. The electrical connection lines 28a, 29a, 29a and 29b
would then pass through the valve arrangements 12a and 12b and be
connected with the control module 61, for instance by way of a
parallel bus between the control module 61 and the valve
arrangements 12a and 12b.
[0057] In accordance with a further development of the invention
the bus interface modules 64a and 64b and the communication modules
44a and 44b associated with them could be arranged together as a
separate sub-assembly, which could for example be arranged on a
valve cluster or on a control module.
[0058] The connections 42 and 43 for the sensors 37 and 38 are
wired or wireless connections. The sensors 37 and 38 would be
designed as so-called transponders, for example, in the case of
wireless connections.
[0059] The electrical components of the actuator 10, for instance
the communication module 42 and the energy converter 33 may be at
least in part arranged together as a common sub-assembly. Same can
for example be arranged on the cylinder 11, for instance in a head
of the cylinder 11.
[0060] In the illustrated working examples the compressed air lines
13 and 14 respectively have but one single electrical conductor. It
is however also possible in principle to have further electrical
conductors for other purposes.
* * * * *