EP0624831A2 - Controlsystem to be used in cooperation with fluid actuated systems - Google Patents

Abstract

A control system is proposed which is to be used in conjunction with fluid-actuated systems. It has a valve station (4), which contains a plurality of valves (13) and valve drives (35), which are allocated to the said valves and can be actuated electrically with the cooperation of an electronic control unit (24). In addition, it is equipped with at least one signal connection (72) for a signal conductor (34) leading away from the valve station (4). At least one signal connection (32) is the input (32') and/or output (32'') of a signal transducer (37, 38), which is a component of the valve station (4). The relevant signal transducer (37, 38) is capable of converting ingoing non-electrical control signals into electrical signals which can be processed by the control unit (24), and/or vice versa. <IMAGE>

Description

The invention relates to a control device for use in connection with fluid-actuated devices, for example working cylinders, with a valve station which contains a plurality of valves and associated valve drives which can be actuated electrically with the assistance of an electronic control unit, and with at least one signal connection for a signal conductor leading away from the valve station Is provided.

A control device of this type emerges from the German utility model G 92 11 109. It contains a valve station that has a module-like structure and is also referred to as a "valve island" or "installation island". A plate-like fluid distributor is equipped with a plurality of pneumatic valves, which have a valve drive which is actuated electrically to switch the associated valve. In particular, electromagnets or so-called solenoid valves come into consideration as valve drives. Devices that can be actuated fluidically, for example working cylinders, can be connected to the valves.

The actuation signals for the valve drives are supplied by an electronic control unit, which can be part of the valve station. The valve station also has several signal connections to which signal conductors leading to monitoring devices such as sensors can be connected in order to receive control signals which the control unit can process.

So far, it has only been provided to use so-called reed contacts as sensors and to transmit the control signals supplied by them electrically to one of the signal connections of the valve station, which in this case is designed as a digital signal input. However, there is an increasing need to control complex systems or machines, so that one reaches certain limits with the previous equipment of the valve stations. It is therefore the object of the present invention to provide a control device of the type mentioned at the outset which can be used more flexibly with little assembly effort.

This object is achieved in that at least one signal connection is the input and / or output of a signal converter which is part of the valve station and which converts incoming non-electrical control signals into electrical signals which can be processed by the control unit and / or the electrical signals influenced by the control unit in outgoing non-electrical Control signals converted.

In this way, signal converters are practically integrated in the valve station, which can receive and / or output non-electrical control signals by converting them into electrical signals in the case of reception and generating them from electrical signals in the case of transmission. The user only has to lay the necessary signal conductors without the need to install a suitable signal converter at the point to be monitored apart from the valve station. If, for example, it is a signal converter that converts between fluid pressure control signals and electrical signals, fluid lines can be laid starting from the object to be monitored directly to the valve station and connected there to the assigned signal connection without requiring an electrical connection. The same applies, for example, to an integrated signal converter which converts between optical control signals and electrical signals. In this case, it may be sufficient to lay a light guide as a signal guide to the object to be monitored and, for example, to implement a reflex light barrier in this way. The conversion can take place in each case from electrical to non-electrical and / or from non-electrical to electrical signals. In the latter case, there is the possibility of using the assigned signal connection as a non-electrical output in order to correspond to the control by the electronic Control unit, for example, to send out pneumatic pulses or light signals that are used elsewhere. Since the signal converters are part of the valve station, they can be placed together with the valve station at a location that is not exposed to any significant interference. Placing them individually at the respective monitoring location could cause considerably more disturbances caused by environmental influences, especially if analog signals are to be processed.

Advantageous developments of the invention are listed in the subclaims.

The control signals which are fed to a signal connection of a signal converter are, in particular, monitoring signals which can be used for monitoring the operation of fluid-operated devices or other components of a machine or system. The most common way to monitor movements or positions of objects or fluid pressures. The connected electronic control unit can use the monitoring signals to actuate the valves as required.

It is advantageous if the valve station has a modular structure, so that the user only has to install those components that he really needs in individual cases. In this context, it is advantageous if carrier modules are present, which are equipped with signal converters, and which can be detachably attached to the valve station in a number that can be detached, similar to a battery. It is possible to design individual ones of the carrier modules exclusively as input modules or as output modules which only have signal connections functioning as inputs or outputs. This simplifies the clarity of the overall arrangement. It is furthermore expedient if a fluid distributor carrying the valves is provided, which is likewise in several parts and is composed of a plurality of distributor modules with which the valve station is equipped in the desired number and sequence as required. In this context, it is advantageous to equip the valve station with a control block to which the carrier modules on the one hand and the distributor modules on the other hand are attached. A fieldbus communication unit, an electronic control unit equipped with a control program or a combination of both can be used as the control block.

It is of course possible, in addition to the non-electrical inputs and / or outputs, to provide electrical inputs and / or outputs, which can be of an analog and / or digital type. In this way, electrical signals can also be fed in or sent out.

Figur 1

eine bevorzugte Bauform der erfindungsgemäßen Steuereinrichtung, wobei verschiedene Möglichkeiten zur Verwendung der Signalanschlüsse aufgezeigt sind,

Figur 2

ein mit zwei Signalwandlern ausgestattetes Trägermodul in Stirnansicht gemäß Schnittlinie II-II aus Figur 1 und

Figur 3

ein weiteres Trägermodul in einer der Figur 2 vergleichbaren Darstellungsweise gemäß Schnittlinie III-III aus Figur 1, das mit anderen Typen von Signalwandlern ausgestattet ist.

The invention is explained in more detail below with reference to the accompanying drawing. In this show:

Figure 1

a preferred design of the control device according to the invention, various options for using the signal connections being shown,

Figure 2

a carrier module equipped with two signal converters in front view according to section line II-II from Figure 1 and

Figure 3

a further carrier module in a representation comparable to FIG. 2 according to section line III-III from FIG. 1, which is equipped with other types of signal converters.

FIG. 1 shows a control device 1 which, according to the example, is used to control a fluid-actuatable device 2 in the form of a pneumatic working cylinder 3. The main component is a valve station 4, which is shown in a simplified plan view. The same represents a unit composed of several assemblies, which can be transported, assembled or otherwise handled as a whole. The valve station 4 and the devices 2 to be actuated can be as far apart from one another and are connected to one another via suitable lines. The particularly advantageous feature of a valve station 4 is that it supplies the devices to be controlled centrally with it Actuation energy is possible, which considerably simplifies the installation of entire systems or machines.

The valve station 4 according to the example has a fluid distributor 5, which can be a one-piece plate-like component. Central fluid channels 6 for supplying and / or discharging the pneumatic working medium, here compressed air, run inside the fluid distributor 5. A connection module 7 flanged on the end allows the connection of suitable external pressure medium lines or silencers, which are not shown in detail, but one can see the channel openings 8 forming the corresponding connection openings.

The upper side of the fluid distributor 5 facing the viewer in FIG. 1 forms an assembly surface 12 on which a plurality of working valves 13, which are generally designed as multi-way valves, are arranged transversely aligned in the longitudinal direction 11 of the fluid distributor 5. They are connected to the fluid channels 6 via transverse channels (not shown in detail) of the fluid distributor 5.

On the side of the fluid distributor 5, in particular in a connection surface 14 which runs at right angles to the mounting surface 12, there are a plurality of consumer connections 15 which communicate with the working valves 13 via distribution channels which run in the fluid distributor 5 and are not shown in detail. Each working valve 13 is at least one such consumer connection 15 assigned, usually it is two pieces. Depending on the switching position of the working valves 13, the assigned consumer connections 15 are connected to one or the other of the fluid channels 6 via the working valves 13 for supply or ventilation.

In the exemplary embodiment, for the sake of simplicity, only one fluid-actuatable device 2 is shown, which is a double-acting working cylinder 3. It is connected via two pressure medium lines 16 to two consumer connections 15 assigned to one of the working valves 13. Depending on the switching position of the relevant working valve 13, an extension stroke, a retracting stroke or the standstill of the piston 17 or a piston rod 18 of the working cylinder 3 connected to it can be caused.

The fluid distributor 5 is flanged to a working side 22 of a control block 23. The latter is therefore located on the side of the fluid distributor 5 opposite the connection module 7. The control block 23 forms, for example, an electronic control unit 24 which contains a program memory in which a control program is stored. It is preferably a programmable logic controller. A computer (PC), not shown, can be connected via an interface 25 in order to program the control unit 24. At least one further interface 26 forms a fieldbus connection, can be connected to the further valve stations 4 arranged downstream via bus lines (not shown in more detail), which either work depending on the exemplary valve station 4 or have their own intelligence in the form of a control unit.

The control block 23 of the exemplary embodiment can also be formed by a pure fieldbus communication unit which does not contain its own control program. In this case, an electronic control unit that takes over control would have to be provided elsewhere, which may be a separate control unit or a control unit integrated in the control block 23 of another valve station 4.

A pure distribution block for electrical signals would also be conceivable as control block 23, in which case an additional control unit would be provided, the connection now being made not via a fieldbus but via multipole lines.

The control block 23 is equipped with a further mounting surface, which is opposite the working side 22 in the exemplary embodiment and is referred to below as the control side 27. A carrier 28 is attached to it, on which at least one and preferably a plurality of signal connections 32, which are yet to be explained, are provided and, moreover, with one or more can be equipped with further signal connections 33, which form digital and / or analog inputs and / or outputs for electrical control signals. Signal conductors 34, via which control signals arrive and / or are transmitted, can in particular be detachably connected to the signal connections 32, 33. Incoming signals are predominantly monitoring signals which provide information about certain operating states of devices 2 to be controlled or of other parameters, the knowledge of which is required for the control of a device 2 which can be actuated in particular by fluid.

Each work valve 13 is assigned an electrically actuable valve drive 35, which is in particular attached directly to the work valve 13 in question. These are preferably solenoid valves which contain at least one electromagnet. They receive their electrical actuation signals via at least one electrical conductor 36, which runs in particular within a housing in the longitudinal direction of the fluid distributor 5, into which the valve drives 35 have electrical access. Said housing can be formed separately, but it is preferably formed directly by the fluid distributor 5, which can contain suitable conductor channels. The electrical conductors 36 are connected to the control block 23, from where the actuation signals come, which are generated taking into account in particular the control signals applied to the signal connections 32, 33.

The valve station 4 of the exemplary embodiment has a plurality of signal connections 32 which each form the input 32 ′ of a signal converter 37 which is part of the valve station 4. Furthermore, there are signal connections 32, which each form the output 32 ″ of a signal converter 38, which also belongs to the valve station 4. The signal converters 37 convert incoming non-electrical control signals at the assigned input 32 ′ into electrical signals that the electronic control unit 24 can process The signal converters 38 communicating with an output 32 'are able to convert electrical signals coming from the control unit 24 into non-electrical control signals which can be taken off at the associated output 32'.

In this way, in cases where control signals are based on non-electrical processes, there is no need for electrical wiring to the object to be monitored. If you wanted to monitor a certain pressure in a pressure vessel or in a working cylinder, you would have to install a signal converter on the pressure vessel or working cylinder without the integrated solution according to the invention, which functions as a pressure sensor and converts the pressure signals into an electrical signal, which is then connected via electrical lines an analog input of the valve station is introduced. In the present case, such a signal converter 37 ', which is able to convert fluid pressure control signals into electrical signals, Immediate components of the valve station 4, so that only easily routable pressure medium lines 39 - rigid lines, hoses, other components containing pressure medium channels - need to be laid as signal conductors 34. This can be seen from Figures 1 and 3. The electrical signal generated by the signal converter 37 'from pressure signals is conducted via at least one electrical conductor 43 into the control block 23, the necessary electrical conductors 43 expediently running inside the carrier 28.

As a further equipment example, a signal converter 37 ″ is provided in the valve station 4, as can be seen in FIGS. 1 and 2, and is capable of converting optical control signals present at the input 32 ′ into electrical signals, which likewise lead to the control block 23 via electrical conductors 43 will. In this case, the signal conductors 34 can be designed as light guides 44, which enable optical object detection and can be laid very easily. In this way, for example, reflex light barriers can be implemented.

In a corresponding manner, pressure signals or optical signals can be taken off at the outputs 32 ″ if the assigned signal converters 38 are able to convert electrical signals received from the control block 23 via electrical conductors 45 into, for example, pneumatic pressure signals (signal converter 38 ′) or into optical ones Convert signals (signal converter 38 ''). The electrical conductors 45 are expediently in accordance with electrical conductors 43 laid.

It goes without saying that the signal connections 32 are expediently designed in such a way that the corresponding pressure medium conductors 39 or light guides 44 can be detachably connected without problems.

The valve station 4 of the exemplary embodiment can also process incoming electrical control signals. These are fed into the further signal connections 33, to which no signal converter is assigned, and which pass on the control signals, amplified or unreinforced in their capacity as electrical signals, to the control block 23 via suitable electrical conductors. In this way, in particular electrical control signals from capacitive, inductive or reed-contact-based sensors 46 can be processed.

It is understood that the valve station 4 can be equipped with any number of the explained signal connections 32 of any kind. In particular, it would be possible to equip the valve station 4 only with those signal converters that are capable of converting non-electrical input signals into signals that can be further processed electrically. As a rule, however, it should be the case that at least one further signal connection 33 is additionally present, which can receive or emit electrical signals without prior signal conversion.

The exemplary valve station 4 has a modular structure. This allows the user to adapt the scope of equipment to the needs and make later extensions if necessary.

The modular structure is first of all evident in the fact that the carrier 28 is preferably composed of a plurality of individual carrier modules 47 which are detachably connected to one another. For example, block-like carrier modules 47 are arranged in a row in succession, the first carrier module 47 'being attached to the control block 23 and the remaining carrier modules 47 being connected to the carrier module 47' on the end face opposite the control block 23. Each carrier module 47 can be equipped with one or more signal connections 32 and with one or more of the signal converters 37, 38. It is expedient here if the signal converters 37, 38 are received in a protected manner inside the assigned carrier module 47, in particular in such a way that only the assigned signal connection 32 is visible and accessible.

The electrical connection between the individual carrier modules 47 and the control block 23 is expediently carried out in such a way that 47 sections of the electrical conductors 43, 45 are formed within each carrier module, which sections can be plugged together to form a wiring harness, with suitable plug connectors 47 at the subdivisions between immediately adjacent carrier modules 48 are provided which, when adjacent carrier modules 47 are placed next to one another, in particular automatically engage with one another.

It is possible to design individual ones of the carrier modules 47 exclusively as input modules 49 or as output modules 50, the signal connections 32, 33 of which are designed exclusively as inputs or as outputs. It is also possible to provide at least one carrier module which has only those signal connections 32 to which a signal converter 37, 38 is assigned, the corresponding signal converters being integrated in the relevant carrier module, as shown in FIGS. 2 and 3. There, however, the possible mixture is shown, according to which at least one carrier module 47 contains only identical signal converters 37, 38, which differ only in terms of the assignment in terms of output and input. It can be seen that any combinations are possible in order to make the valve station as flexible as possible.

In the exemplary embodiment, the fact that the fluid distributor 5 is composed of a plurality of distributor modules 54, which are arranged in a row in a row corresponding to the carrier modules 47 and which each carry at least one of the working valves 13, also contributes to the flexible structure. In the exemplary embodiment, each distributor module 54 is equipped with two working valves 13. The first distributor module 54 'is located directly on Control block 23, the further distribution modules 54 connect to the first distribution module 54 'on the end face opposite the control block 23. It goes without saying that in this case the fluid channels 6 as well as the at least one electrical conductor 36 can be divided into individual sections which run in the respective distributor module 54 and, when the distributor modules 54 are assembled, add up to form a continuous strand.

Overall, there is a valve station or valve terminal which has an extremely modular structure. The equipment can be adapted to the respective task and subsequently changed. The control block 23 expediently contains the central control electronics, which can be designed in particular as a fieldbus communication unit (fieldbus node) or as an electronic control unit (control node) for programming. On one side of the control block 23, valve-equipped manifold modules 54 can be arranged, whereby, when equipped with pneumatic valves, one could speak of pneumatic modules as a whole, which are composed of a basic unit in the form of the carrier module 47 and the working valve or valves sitting thereon. The electromagnets of the valve drives 35 are electrically actuated via the actuation block 23.

On the side of the control block opposite the carrier modules 47 23 different control modules can be arranged, the order and configuration of which can be freely selected, so that one can use both pure input modules and output modules or combined input and output modules.

The integration of signal converters 37, 38 in the valve station or valve terminal results in a reduction in costs and a simple installation for the user with a simultaneously reduced problem of interference. Signal converters 37, in which the existing signal connection (s) 32, 32 ′ act as an input, can practically contain a sensor that operates on a non-electrical basis, for example a pressure sensor or an optical sensor, with only one non-electrical signal conductor then leading to the monitoring point is misplaced and in the signal converter 37 itself the conversion into electrical signals that can be processed by the control unit 24 takes place. Since signal converters regularly also require electrical supply energy in order to be able to be operated, one saves not only electrical signal conductors which are replaced by the non-electrical ones, but also electrical supply lines which can now also be integrated in the carrier 28.

Claims (15)

Control device for use in connection with fluid-actuated devices, for example working cylinders, with a valve station which contains a plurality of valves and associated valve drives which can be actuated electrically with the aid of an electronic control unit, and which is equipped with at least one signal connection for a signal conductor leading away from the valve station characterized in that at least one signal connection (32) is the input (32 ') and / or output (32'') of a signal converter (37, 38) which is part of the valve station (4), and the incoming non-electrical control signals in from the Control unit (24) converts processable electrical signals and / or converts the electrical signals influenced by control unit (24) into outgoing non-electrical control signals. Control device according to Claim 1, characterized in that at least one signal converter (37, 37 '; 38, 38') is designed to convert between fluid pressure control signals and electrical signals. Control device according to claim 1 or 2, characterized in that at least one signal converter (37, 37 '; 38, 38') is designed for conversion between pneumatic control signals and electrical signals. Control device according to Claim 2 or 3, characterized in that at least one signal conductor (34) designed as a fluid line (39) is connected directly to the signal connection (32) of the assigned signal converter (37, 37 '; 38, 38'). Control device according to one of claims 1 to 4, characterized in that at least one signal converter (37, 37 ''; 38, 38 '') is provided for the conversion between optical control signals and electrical signals. Control device according to Claim 5, characterized in that at least one signal conductor (34) in the form of a light guide (44) is connected directly to the signal connection (32, 32 ', 32'') of the assigned signal converter (37, 37'; 38, 38 ') . Control device according to one of claims 1 to 6, characterized in that the control signals fed to a signal connection (32) functioning as an input (32 ') are monitoring signals. Control device according to one of Claims 1 to 7, characterized in that at least one signal converter (37, 38) is arranged in or on a carrier module (47) which can be detachably fixed to the valve station (4). Control device according to Claim 8, characterized in that a plurality of carrier modules (47) can be fixed in series at the valve station (4). Control device according to claim 8 or 9, characterized in that at least one carrier module (47) is an output module (50) equipped exclusively with signal connections (32) designed as outputs (32 '). Control device according to one of Claims 8 to 10, characterized in that at least one carrier module (47) is an input module (49) equipped exclusively with signal connections (32) designed as inputs (32 '). Control device according to one of claims 8 to 11, characterized in that all carrier modules (47) are successive Can be attached to a control side (27) of a control block (23), which is designed in particular as a fieldbus communication unit and / or as an electronic control unit (24) equipped with a programmable program memory in particular, and which communicates with the signal converters (37, 38). Control device according to one of claims 1 to 12, characterized in that the valves (13) are arranged on a fluid distributor (5) which is expediently composed of a plurality of distributor modules (54) each equipped with at least one valve (13). Control device according to claim 13 in conjunction with claim 12, characterized in that the fluid distributor (5) is arranged on the side of the control block (23) opposite the carrier modules (47). Control device according to one of claims 1 to 14, characterized in that the valve station (4) is provided with further signal connections (33) which form digital and / or analog inputs and / or outputs for electrical control signals.

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