EP2865899B1 - Compressed air maintenance unit, consumption control device equipped with the same and associated operating method - Google Patents

Description

• eine elektrisch ansteuerbare Ventileinrichtung, die einen mit einer Druckluftquelle verbindbaren Speiseeingang sowie einen Arbeitsausgang aufweist,
• einen mit einer externen Verbrauchereinrichtung verbindbaren Geräteauslass, der über einen Auslasskanal mit dem Arbeitsausgang der Ventileinrichtung verbunden ist,
• Sensormittel zumindest in Gestalt eines zur Messung des in dem Auslasskanal auftretenden Auslassdurchflusses dienenden Durchflusssensors und eines zur Messung des in dem Auslasskanal herrschenden Auslassdruckes dienenden Auslass-Drucksensors,
• und eine sowohl mit der Ventileinrichtung als auch mit den Sensormitteln signaltechnisch verbundene interne elektronische Steuereinheit, die ausgebildet ist, um in Abhängigkeit von den seitens der Sensormittel gemessenen Zustandswerten der Druckluft ein elektrisches Ventil-Steuersignal für die Ventileinrichtung zu generieren.

The invention relates to a compressed air maintenance device which has the following components:

• an electrically controllable valve device which has a feed input which can be connected to a compressed air source and a working output,
• a device outlet which can be connected to an external consumer device and which is connected via an outlet channel to the working outlet of the valve device,
• Sensor means at least in the form of a flow sensor serving for measuring the outlet flow occurring in the outlet channel and an outlet pressure sensor serving for measuring the outlet pressure prevailing in the outlet channel,
• and an internal electronic control unit which is signal-connected to both the valve device and the sensor means and which is designed to generate an electrical valve control signal for the valve device as a function of the state values of the compressed air measured by the sensor means.

The invention further relates to a consumer control device suitable for controlling a consumer device, which is equipped with at least one compressed air maintenance device of the aforementioned type and a connected thereto or connectable electronic control device.

Moreover, the invention relates to a method for controlling the compressed air supply of a consumer device.

A trained in the aforementioned sense and usable prior art is known from DE 10 2011 012 558 B3 known. This is a compressed air maintenance device that can be fluidly connected to a consumer device to be supplied with compressed air. The compressed air service unit is equipped with a switching valve designed as a 3/3-way valve, which allows three switch positions in which the consumer device can either be connected to a compressed air source or disconnected from the compressed air source, in the two switch positions causing a separation either fluidly shut off or vented to the atmosphere. An outlet channel connecting the switching valve to the consumer device is connected inter alia to a flow sensor, which enables monitoring of the outlet flow, that is to say the flow rate of the compressed air flowing through the outlet channel to the consumer device. The flow sensor is connected to an internal electronic control unit that can operate the 3/3-way valve and is also capable of outputting reusable diagnostic signals.

With the help of the known compressed air maintenance device, a consumer device can be supplied very efficiently with compressed air. For example, the switching valve can be switched to its shut-off position to save compressed air when in the outlet channel for a longer period of time no appreciable flow is detected. The resumption of normal operation, however, requires an external intervention in the system.

From the DE 10 2009 016 069 B3 a method is known which allows a saving of compressed air in pneumatic devices. The method provides to interrupt the supply of compressed air to a pneumatic device by means of a 2/2-way valve, if the pneumatic device is not operated for a long time. The 2/2-way valve is equipped with two pilot valves with which it can be switched to either an open position or a shut-off position.

From the DE 10 2005 057 004 B3 For example, there is known a compressed air conditioning apparatus and associated method of operation wherein the feed inlet is shut off by a shut off valve to prevent pressure loss while regeneration of an integrated air dryer occurs.

The object of the present invention is to take measures that allow in conjunction with a compressed air maintenance device energy-efficient and at the same time comfortable operation of consumer devices operated with compressed air.

1. (a) selbsttätig ein das Proportional-Druckregelventil aus dem Arbeitsmodus in den Stand-by-Modus versetzendes elektrisches Ventil-Steuersignal ausgibt, wenn der Durchflusssensor über einen vorgegebenen oder vorgebbaren Zeitraum hinweg einen einem vorgegebenen oder vorgebbaren Abschalt-Durchflussgrenzwert entsprechenden oder darunter liegenden Durchflusswert detektiert, und dass sie
2. (b) ebenfalls selbsttätig ein das Proportional-Druckregelventil aus dem Stand-by-Modus in den Arbeitsmodus zurückversetzendes elektrisches Ventil-Steuersignal ausgibt, wenn der Durchflusssensor während des Stand-by-Modus einen einem vorgegebenen oder vorgebbaren Einschalt-Durchflussgrenzwert entsprechenden oder darüber liegenden Durchflusswert detektiert.

To solve this problem is provided in a compressed air maintenance device of the type mentioned,
in that the valve device is designed as a proportional pressure regulating valve which, depending on the electrical valve control signal applied to it, can regulate the outlet pressure prevailing in the outlet channel to different outlet pressure values operable to control the outlet pressure to a working pressure value operating mode as well as to a standby mode controlling the outlet pressure to a lower standby pressure value in comparison with the working pressure value,
and that the internal electronic control unit is adapted to

1. (a) automatically outputs an electric valve control signal which puts the proportional pressure control valve out of the working mode into the standby mode when the flow sensor detects a flow value corresponding or below a predetermined or predefinable shutoff flow limit value over a predetermined or predefinable period of time , and that you
2. (b) also automatically outputs an electric valve control signal resetting the proportional pressure control valve from the stand-by mode to the working mode when the flow sensor during stand-by mode has a flow value corresponding to or greater than a predetermined or specifiable on-flow limit detected.

The object is also achieved by a consumer control device, which has a configured in the aforementioned sense compressed air maintenance device and an attached or connectable external electronic control device.

Furthermore, the invention is achieved in a method of the type mentioned, characterized
in that the consumer device is supplied with compressed air through an electrically controllable proportional pressure regulating valve, which has a working outlet connected to the consumer device, at which the compressed air is at a regulated outlet pressure and an outlet flow is available
and in that the outlet flow flowing from the proportional pressure regulating valve to the consumer device is measured, whereby the outlet pressure is automatically regulated from a working pressure value to a corresponding lower standby pressure value by corresponding electrical activation of the proportional pressure regulating valve, if the outlet flow rate exceeds a predetermined or predeterminable period of time has a predetermined or predefinable shutdown flow limit value corresponding or lower flow value
and wherein by appropriate electrical control of the proportional pressure control valve, the outlet pressure is automatically regulated from the standby pressure value back to a higher working pressure value, when the outlet flow has a flow value corresponding to or greater than a predetermined or predefinable switch-on flow limit value.

The compressed air maintenance device according to the invention has a for controlling the output pressure to be controlled electrically controllable proportional pressure control valve. The electrical valve control signal used for this purpose is generated in an internal control unit on the basis of measured values of the flow sensor and of the outlet pressure sensor. The measured values of the outlet pressure sensor, which is an independent pressure sensor or a pressure sensor integrated in the proportional pressure control valve, are used for pressure regulation, so that the connected consumer device can be provided with a very precisely controlled outlet pressure value desired during the working mode. An air-saving effect results from the internal electronic control unit independently operating the proportional pressure control valve in a stand-by mode with reduced outlet pressure can switch or toggles when and as long as due to a break in operation of the connected external consumer device of the outlet side air consumption drops to or below a predetermined threshold, which can be referred to as shutdown flow limit. It is advantageous that the proportional pressure control valve without user intervention is automatically switched back to the working mode, that is, the normal operation, when the outlet side due to a renewed commissioning of the external consumer device again increased air demand occurs. The increased air requirement manifests itself in an increase in exhaust flow detected by the flow sensor. The operating mode is switched back when the measured flow value reaches or exceeds a predetermined threshold, which may be referred to as the turn-on flow limit, and based on which the internal electronic control unit generates a corresponding valve control signal. The inventive measure is particularly suitable for applications with short downtime of the external consumer device and the requirement of a fast compressed air supply at resumption of operation.

Conveniently, therefore, the outlet pressure is automatically adjusted depending on the air requirement by the outlet pressure is automatically regulated to a low stand-by pressure value and again with increasing compressed air demand back to the increased working pressure value at low flow for a long time or below a minimum flow value. The device thus recognizes independently a rising demand for compressed air. Preferably, the stand-by pressure value and / or the working pressure value can be variably predetermined and thus adapted to the respective operating conditions.

The use of a proportional pressure control valve also has the advantage, in comparison with the use of a switching valve, that no additional separate soft-start valve is required to ensure gentle pressure build-up and that the operating noise is relatively quiet.

In the present description and in the claims, the term "flow" is used by way of example and simply for the correct terms such as "volume flow", "flow rate" or "flow rate" and denotes a flow rate per unit time.

Advantageous developments of the invention will become apparent from the dependent claims.

The switch-on flow limit value is expediently higher than the switch-off flow limit value. Preferably, both values can be freely specified.

The electronic control unit is in particular designed such that it automatically permanently deactivates the switching function effecting a changeover from the stand-by mode to the working mode when the outlet pressure sensor detects an outlet pressure that has dropped to zero. In this way, an automatic venting of the connected consumer device is prevented if previously a pressureless operating state had occurred, for example, due to a malfunction or a failure of the compressed air supply. To reactivate the automatic pressure increase, user intervention is required, for example pressing a reset button.

It is further advantageous if the compressed air maintenance device with a designated as inlet pressure sensor Pressure sensor is connected, which is connected to an inlet channel connected to the input of the proportional pressure control valve and measures the prevailing inlet pressure therein. In this way, in particular a constant monitoring is possible to the effect whether the inlet side of the desired system pressure is applied at the correct level.

It should be mentioned at this point that the flow sensor for determining the outlet flow does not necessarily have to be arranged on the outlet side of the proportional pressure control valve, but can also be placed on the inlet side.

The internal electronic control unit is expediently not only able to generate the electric valve control signal for the proportional pressure control valve as required, but is in particular designed so that it can also output at least one electrical diagnostic signal which, with the assistance of the sensor means, ie on the basis of measured values detected by the sensor means. For example, a diagnostic signal can be output when compressed air conditions are determined by the flow sensor and / or a pressure sensor of the compressed air maintenance device, which deviate from the expected or tolerable values in normal operation. Deviating operating states can be based, for example, on leakage or malfunction of components of the connected external consumer device. Conveniently, at least one electrical diagnostic signal can be generated in addition to the electrical valve control signal. Alternatively, however, it may also be provided to directly use the electrical valve control signal itself as a diagnostic signal.

The compressed air maintenance device is expediently directly with optical display means and / or with acoustic warning means equipped to operate on the basis of an electrical diagnostic signal generated by the output means of the internal electronic control unit, to indicate problematic operating conditions directly on site.

The compressed air maintenance device is preferably designed in the form of a modular assembly. The functional components of the device are expediently combined in individual modules, which can be assembled in different combinations depending on the desired degree of equipment. The proportional pressure control valve is expediently part of a valve module which, if present, preferably also contains the inlet pressure sensor. The flow sensor is expediently part of a sensor module, which preferably also includes the outlet pressure sensor. Finally, the internal electronic control unit is expediently part of a control module. At least one further module may be equipped as a communication module having at least one communication interface connected to the internal electronic control unit, which enables electrical communication with at least one external electronic device. Even with non-modular design, the compressed air maintenance device is expediently equipped with at least one communication interface for electrical communication with at least one external electronic device.

The compressed air maintenance device is preferably equipped with one or more communication interfaces to which an external electronic control device, in particular acting as a higher-level controller, and / or an electronic information reader and / or an electronic information input device and / or at least one further external one connect electronic device or leave.

At least one communication interface is expediently used to integrate the compressed air maintenance device into a modular, internally electrically networked system with a local bus system.

For example, at least one communication interface is provided, which is designed as a bus interface for, in particular, a serial data transfer. About such a bus interface, the electronic control unit of the compressed air maintenance device can be networked with other electronic devices via a fieldbus.

At least one communication interface is expediently designed as a digital or analog input or as a digital or analog output.

Preferably, the compressed air maintenance device is also equipped with a communication interface, which is used for communication between the electronic control unit and one or more other compressed air maintenance devices of the same or another compressed air treatment device.

The communication with external devices is particularly wired, but can also be realized wirelessly via appropriately designed communication interfaces. In bus communication, any bus standards can be implemented.

At least one communication interface is expediently suitable for bidirectional signal transmission. In addition, at least one communication interface is expediently designed for input and / or output of binary and / or analog signals. Such a communication interface is expediently present in addition to a communication interface embodied as a bus interface.

In order to influence the operating behavior of the internal electronic control unit and / or the sensor means, the compressed air maintenance device is expediently equipped with suitable input means. Such input means consist for example of at least one button and / or at least one switch, which are arranged outside easily accessible. Additionally or alternatively, input means may also be present in order to be able to carry out purely electrical data and / or signal input, for example via a special operator control device or via an external electronic control device which usually communicates with the compressed air service device. Such input means consist in particular of at least one electrical communication interface.

The equipment of the compressed air maintenance device expediently allows extensive monitoring and diagnostic functions such as comparative measurements, limit monitoring and automatic and / or user-controlled consumption measurements.

Expediently, functions for measuring value compression and data reduction are integrated in the compressed air maintenance device, as well as functions for measured value analysis or statistical functions.

Conveniently, the internal electronic control unit is equipped with storage means in which data of many kinds, in particular measurement, control, diagnosis and / or analysis data, Volatile and / or remanent, ie permanently in case of power failure, can be stored.

The integration of the internal electronic control unit in the compressed air maintenance device has the advantage that an autonomous operation of the compressed air maintenance device is possible without having to rely on continuous signal communication with networked devices or with an external electronic control device, which significantly minimizes the susceptibility. Nevertheless, of course, a bus networking and / or the connection with an external electronic control device is advantageous in order to be able to tune the operating behavior to other components of a system.

The suitably present local signal processing in the internal electronic control unit allows a very high signal sampling rate and a relatively short reaction time in the measurement and control functions, since the transfer times via a connected fieldbus and computing times in an external electronic control device omitted. For the transfer of measurement, status, control and parameter data, the compressed air service unit can be equipped with bus interfaces of all common fieldbus protocols.

By selecting a suitable equipment scope, the compressed air service unit can be designed as a fieldbus-capable system with an electrical interface for system parameterization and for transmission of measurement and control data. Optional measures for local operation and visualization, for example via an optionally integrable display or via a locally connectable display and operating device, are also possible.

In a further embodiment, the compressed air maintenance device is a stand-alone system which has at least one digital input and / or at least one digital output, so that a local operation and visualization can be carried out via locally available means. The following application variants can preferably be implemented by means of a modular system structure: as an autonomous standalone device, as a fieldbus-networked, independently operating single device and as a function module that can be integrated in maintenance devices with or without fieldbus connection.

• das elektrisch ansteuerbare Proportional-Druckregelventil, das einen mit einer Druckluftquelle verbindbaren Speiseeingang und den Arbeitsausgang aufweist,
• einen mit der externen Verbrauchereinrichtung verbindbaren Geräteauslass, der über einen Auslasskanal mit dem Arbeitsausgang des Proportional-Druckregelventils verbunden ist,
• Sensormittel zumindest in Gestalt eines zur Messung des in dem Auslasskanal auftretenden Auslassdurchflusses dienenden Durchflusssensors und eines zur Messung des in dem Auslasskanal herrschenden Auslassdruckes dienenden Auslass-Drucksensors,
• und eine sowohl mit dem Proportional-Druckregelventil als auch mit den Sensormitteln signaltechnisch verbundene interne elektronische Steuereinheit, die ausgebildet ist, um in Abhängigkeit von den seitens der Sensormittel gemessenen Zustandswerten der Druckluft ein elektrisches Ventil-Steuersignal für die Ventileinrichtung zu generieren,

wobei das Proportional-Druckregelventil in Abhängigkeit von dem an ihm anliegenden elektrischen Ventil-Steuersignal den im Auslasskanal herrschenden Auslassdruck auf unterschiedlich hohe Auslassdruckwerte regeln kann, wobei es sowohl in einem den Auslassdruck auf einen Arbeits-Druckwert regelnden Arbeitsmodus als auch in einem den Auslassdruck auf einen im Vergleich zum Arbeits-Druckwert geringeren Stand-by-Druckwert regelnden Stand-by-Modus betreibbar ist,
wobei das Proportional-Druckregelventil ferner mittels eines von der internen elektronischen Steuereinheit generierten elektrischen Ventil-Steuersignals automatisch aus dem Arbeitsmodus in den Stand-by-Modus umgeschaltet wird, wenn der Durchflusssensor über einen vorgegebenen oder vorgebbaren Zeitraum hinweg einen einem vorgegebenen oder vorgebbaren Abschalt-Durchflussgrenzwert entsprechenden oder darunter liegenden Durchflusswert detektiert,
und wobei das Proportional-Druckregelventil mittels eines von der internen elektronischen Steuereinheit generierten elektrischen Ventil-Steuersignals automatisch aus dem Stand-by-Modus in den Arbeitsmodus zurückgeschaltet wird, wenn der Durchflusssensor während des Stand-by-Modus einen einem vorgegebenen oder vorgebbaren Einschalt-Durchflussgrenzwert entsprechenden oder darüber liegenden Durchflusswert detektiert.In an advantageous embodiment of the method according to the invention a compressed air maintenance device is used for its implementation, which has the following components:

• the electrically controllable proportional pressure control valve, which has a supply input connectable to a compressed air source and the working output,
• a device outlet which can be connected to the external consumer device and which is connected via an outlet channel to the working outlet of the proportional pressure regulating valve,
• Sensor means at least in the form of a flow sensor serving for measuring the outlet flow occurring in the outlet channel and an outlet pressure sensor serving for measuring the outlet pressure prevailing in the outlet channel,
• and an internal electronic control unit, which is signal-connected to both the proportional pressure regulating valve and the sensor means and which is designed to be measured as a function of the values measured by the sensor means Condition values of the compressed air to generate an electrical valve control signal for the valve device,

wherein the proportional pressure control valve in response to the voltage applied to it electric valve control signal can control the outlet pressure prevailing in outlet pressure to different high outlet pressure, wherein there is both in the outlet pressure to a working pressure value regulating working mode and in the outlet pressure to a can be operated in comparison to the working pressure value lower standby pressure value controlling standby mode,
wherein the proportional pressure control valve is further automatically switched from the working mode to the standby mode by means of an electric valve control signal generated by the internal electronic control unit, if the flow sensor over a predetermined or predeterminable period of time a predetermined or predetermined shutdown flow limit corresponding or lower flow rate detected,
and wherein the proportional pressure regulating valve is automatically switched back from the standby mode to the working mode by means of an electrical valve control signal generated by the internal electronic control unit, when the flow sensor during the standby mode, a predetermined or predetermined turn-on flow limit corresponding or higher flow value detected.

Figur 1

in schematischer Darstellung einen bevorzugten Aufbau der erfindungsgemäßen Verbrauchersteuervorrichtung mit einem darin integrierten erfindungsgemäßen Druckluft-Wartungsgerät eines besonders zweckmäßigen Aufbaus, und

Figur 2

ein Diagramm zur Verdeutlichung einer bevorzugten Betriebsweise einer Verbrauchersteuervorrichtung bzw. des Druckluft-Wartungsgerätes.

The invention will be explained in more detail with reference to the accompanying drawings. Show:

FIG. 1

a schematic representation of a preferred construction of the consumer control device according to the invention with an inventive integrated therein Compressed air maintenance unit of a particularly useful construction, and

FIG. 2

a diagram illustrating a preferred operation of a consumer control device or the compressed air maintenance device.

The designated in its entirety by reference numeral 1 consumer control device contains as a main component at least one preferably in the form of a self-supporting unit trained compressed air service unit 2. This compressed air maintenance device 2 is advantageously modular and can also, if necessary, together with other maintenance modules, one of which at 3 dash-dotted lines are summarized to a compressed air treatment device 4. As at least one further maintenance module, for example, a filter module and / or an air drying module are present.

The compressed air maintenance device 2 has a device housing 5, illustrated in a simplified manner as a frame, which carries and / or contains the further components of the compressed air service device 2. The device housing 5 is expediently modular.

Externally on the device housing 5 are a device inlet 6 and a device outlet 7, which are each suitable for producing a fluid connection. The device inlet 6 is designed to be connected to a compressed air source P via a fluid line designated as a feed line 12. Shown is the connected to the device inlet 6 state of such a compressed air source P.

The device outlet 7 is designed to connect to a leading to an external consumer device A, designated as working line 13 fluid line can. Shown is a state in which a consumer device A - for example, a machine having a plurality of fluid-operated working components - connected to the device outlet 7.

The compressed air maintenance device 2 has an electrically controllable proportional pressure control valve 14. This is conveniently housed inside the device housing 5 and preferably part of a valve module 14a of the modular compressed air service unit 2. The proportional pressure control valve 14 has expediently two, a feed input 16 and It also has an electrical control input 27a, to which an electrical valve control signal can be fed, which specifies the desired value for an outlet pressure to be provided regulated at the working outlet 17.

The proportional pressure regulating valve 14 expediently contains a control unit 15 in which an outlet pressure force based on the outlet pressure is compared with a variably predeterminable actuating force corresponding to the desired value, the working output 17 being connected to the feed inlet 16 or to the venting outlet 18, depending on the balance of forces becomes. The actuating force results, for example, from an electromotive force variable in its bias or from an electromagnetically or electrodynamically generated force or from a fluidic pressure force. The proportional pressure control valve 14 may for example be operated directly electrically or electro-pneumatically pilot-operated, each of which mentioned electrical Valve control signal for the electrical operation or control ensures and sets the setpoint. For example, the proportional pressure regulating valve 14 could have a piezoelectric structure.

The proportional pressure regulating valve 14 is able to regulate the outlet pressure prevailing at the working outlet 17 or in the outlet channel 22 to different outlet pressure values as a function of the electrical valve control signal applied to its control input 27a.

A configuration is possible in which the complete signal processing and signal processing (control algorithm) as well as the valve control (only actuating signal) are taken over by the internal electronic control unit 26.

The feed input 16 is permanently connected to the device inlet 6 via an internal inlet channel 11 of the compressed air service device 2. The working outlet 17 is connected via an internal outlet channel 22 of the compressed air maintenance device 2 with the device outlet 7 in connection, whereupon the outlet pressure is present. The inlet channel 11 and the outlet channel 22 expediently run in the interior of the device housing 5.

The proportional pressure control valve 14 causes a constant compressed air connection between the compressed air source P and the consumer device A in trouble-free operation. Depending on the setting of the proportional pressure control valve 14, the consumer device A is provided regardless of the flow, an outlet pressure in a controlled height.

The compressed air maintenance device 2 is equipped with sensor means 20 for detecting at least a plurality of state variables of the compressed air in the system. These sensor means 20 include a discharge flow occurring in the outlet passage 22 and in particular connected to the outlet channel 22 flow sensor 25 and also connected to the outlet channel 22 and therefore referred to as outlet pressure sensor 24 pressure sensor which detects the pressure prevailing in the outlet channel 22 outlet pressure.

In an embodiment not shown, the flow sensor 25 and / or the outlet pressure sensor 24 are directly an integral part of the proportional pressure regulating valve 14.

Optionally and preferably, the sensor means 20 also contain a further pressure sensor connected to the inlet channel 11 and therefore designated as an inlet pressure sensor 31.

The flow sensor 25 and the outlet pressure sensor 24 are expediently part of a sensor module 25a of the compressed air maintenance device 2. The optional inlet pressure sensor 31 is expediently part of a proportional pressure control valve 14th containing valve module 14a.

The flow sensor 25 is capable of determining the current flow rate of the compressed air flowing through the outlet channel 22, that is to say the flow of this compressed air. In the following, this measured flow is also referred to as outlet flow. The outlet pressure sensor 24 is capable of measuring the pressure prevailing in the outlet channel 22, this pressure also being referred to below as the outlet pressure. The inlet pressure sensor 31 is capable of measuring the pressure prevailing in the inlet duct 11, wherein this pressure is also referred to below as inlet pressure.

The compressed air maintenance device 2 contains a preferably housed inside the device housing 5 internal electronic control unit 26, which is equipped with at least one microprocessor or microcontroller. For simplification, it will also be referred to hereinafter only as "internal control unit 26". The internal control unit 26 is preferably part of a control module 26 a of the compressed air maintenance device 2.

The internal control unit 26 is signal-technically or electrically via internal electrical signal lines 27 of the compressed-air service device 2 with the electrical control input 27a of the switching valve 14, with the flow sensor 25 and with the outlet pressure sensor 24 and, if present, with the inlet pressure sensor 31 connected. The internal control unit 26 may receive electrical pressure readings and flow readings from the sensor means 20 and may output an electrical valve control signal to the proportional pressure control valve 14 and, preferably, also electrical diagnostic signals.

The proportional pressure control valve 14 is operable in two different operating modes, between which it is switchable. The switching is automatically caused by the electric valve control signal in response to the flow rate detected by the flow rate sensor 25 without external intervention. An operating mode is a working mode that is present when the consumer device A is in operation and in which the outlet pressure is regulated to a predetermined working pressure value, for example 6 bar. This desired working pressure value is used as a reference value in the internal control unit 16 is stored and can conveniently be changed application-specific from the outside if necessary.

Another operating mode of the proportional pressure regulating valve 14 is a standby mode in which the outlet pressure is regulated to a lower standby pressure value in comparison to the working pressure value. This stand-by pressure value is for example 2 bar. Also, the desired stand-by pressure value is stored as a reference value in the internal control unit 16 and can conveniently be changed application-specific from the outside if necessary.

The compressed air maintenance device 2 is equipped with an electrical interface which is designated below for better distinction as the first communication interface 28 and which enables signal-technical communication between the internal control unit 26 and the external electronic control unit 23. The first communication interface 28 is arranged in particular on an outer side of the device housing 5 and expediently connected to the internal control unit 26 via internal electrical conductors 32. Preferably, the first communication interface 28 of electromechanical type and in particular designed as a plug-in interface or plug connection device, so that a only schematically indicated external signal cable 33 in particular releasably connect, which allows connection to the external electronic control device 23.

The first communication interface 28 is preferably a bus interface capable of transmitting serial bus signals between the internal control unit 26 and the external electronic control unit 23. The external signal cable 33 may as well as the internal be implemented electrical conductor 32 in the form of a serial bus system.

Alternatively, the first communication interface 28 may also be designed as a wireless interface in order to be able to communicate with the external electronic control device 23 in particular via radio signals.

Preferably, the first communication interface 28 is located on the control module 26a.

The internal control unit 26 preferably has electronic storage means 34, comparator means 35 and dispensing means 36. The storage means 34 can be used, for example, for pressure values relating to the outlet pressure measured by the outlet pressure sensor 24, and also for flow values of the outlet flow rate related to the flow sensor 25 and optionally also for pressure values regarding the inlet pressure measured by the inlet pressure sensor 31 as reference information and preferably also as actual information. In particular, at least one switch-off flow limit value and at least one switch-on flow limit value can be stored in the storage means 34, which are used for an advantageous mode of operation of the consumer control device 1.

The comparator means 35 are able to compare stored reference information with, in particular, also cached or also directly measured actual information. The output means 36 are capable of outputting at least one electrical signal as a function of the comparison result determined by the comparator means 35. By way of example, the dispensing means 36 are designed to be the same for the proportional pressure control valve 14 output specific electrical valve control signal as well as at least one otherwise usable electrical diagnostic signal.

In particular, the output of the proportional pressure control valve electrical valve control signal is based on a comparison of the measured outlet flow rate with the shutoff flow limit value and the turn on flow limit value.

Preferably, the output means 36 of the internal control unit 26 also output an electrical diagnostic signal to the first communication interface 28, from where it can be transmitted to the external electronic control device 23 for further processing as required.

At least one electrical diagnostic signal may also be supplied to optical display means 37 of the compressed air service device 2 to visualize it in any manner.

It is also possible that the compressed air maintenance device 2 is equipped with only indicated by dashed lines acoustic warning means 38, such as a buzzer, so that when receiving a corresponding electrical signal on site an audible warning signal can be issued.

During operation, the internal control unit 26 can receive and process measurement signals originating from the flow sensor 25 and from the outlet pressure sensor 24 and / or from the optionally available inlet pressure sensor 31 as actual information. In this way, the internal control unit 26 receives, as a function of time, current values of the outlet flow rate and of the outlet pressure as well as optionally also the inlet pressure as actual information. The internal control unit 26 may be configured to output this actual information electrically or visually on the first communication interface 28 and / or on the optical display means 37.

Expediently, during operation of the consumer control device 1, the internal control unit 26 can generate at least one electrical diagnostic signal from a comparison between measured actual information and stored reference information, which provides information about the energy situation of the connected consumer device A.

For example, for monitoring the output flow rate, only one or multiple recordings of actual information of the output flow rate can take place, wherein a multiple recording of actual information, in particular with temporal regularity, can take place.

The compressed air maintenance device 2 expediently allows a particularly advantageous flow monitoring of the outlet flow. This takes place in particular during the working mode of the proportional pressure regulating valve 14. In this case, compressed air flows from the compressed air source P to the consumer device A and operates there one or more activatable by fluid force working components of the consumer device A. One or more of these working components are, for example, pneumatic actuators. By comparing the detected exhaust flow actual information with stored reference values, it is very easy to monitor whether increased air consumption occurs during the operating cycle of the consumer device A or during certain phases or sub-cycles of the operating cycle, which is indicative of malfunction or faulty working components.

Even in the case of flow monitoring, the internal control unit 26 is preferably designed such that it outputs an electrical diagnostic signal if a determined actual information deviates from the assigned reference information by a predetermined tolerance value, in particular if the air consumption differs significantly from a reference value.

The internal control unit 26 is designed, or at least programmable, to generate an electrical signal that switches the proportional pressure control valve 14 between the work mode and the standby mode, depending on the comparison result determined by the comparator 35 it is the already mentioned electrical valve control signal. Based on the diagram of FIG. 2 Hereinafter, a preferred operation will be described.

In the diagram, "P2" indicates the outlet pressure, "Q" the outlet flow, and "t" the time.

In the working mode of the consumer device A, in which the consumer device A has a certain compressed air demand, is the proportional pressure control valve 14 in its working mode, the in FIG. 2 marked with "AM". The outlet pressure is regulated to a working pressure value "P2 _A ".

During the working mode, the outlet flow rate "Q" is continuously measured by the flow sensor 25 and transmitted to the internal control unit 16 as actual information. There is a comparison with the stored shutdown flow limit instead of in FIG. 2 denoted by "AW".

If the flow sensor 25 detects a reduced flow value corresponding to or lower than the shutdown flow limit value over a predetermined tolerance period "t _T ", the internal control unit 16 generates a valve control signal which switches over the proportional pressure control valve 14 the work mode "AM" in the stand-by mode, which in FIG. 2 denoted by "SM". Thereby, the regulated outlet pressure P2 is lowered to a likewise regulated standby pressure value "P2s", which is lower than the working pressure value "P2 _A " which minimizes the compressed air consumption.

During the stand-by mode, the outlet flow rate "Q" is continuously measured by the flow sensor 25 and transmitted to the internal control unit 16 as actual information. There, during the stand-by mode, a comparison with the stored turn-on flow limit takes place FIG. 2 denoted by "EW".

Determines the flow sensor 25 during standby mode again higher flow value "Q", which corresponds to the stored switch-on flow limit "EW" or above, this is interpreted as increased compressed air demand of the consumer device A and the internal control unit 16 generates an electrical Valve control signal by which the proportional pressure control valve 14 is switched back from the stand-by mode to the working mode. Thereby, the regulated outlet pressure P2 is raised again to the higher regulated working pressure value "P2 _A ".

Preferably, the turn-on flow limit value "EW" is higher than the turn-off flow limit value "AW".

As a safety function, the internal electronic control unit 26 is preferably designed such that it automatically deactivates the switching function effecting a changeover from the stand-by mode to the working mode when the outlet pressure sensor 24 detects an outlet pressure "P2" that has fallen to zero. In this way, an automatic venting of the connected consumer device A is prevented if previously an unpressurized operating state had occurred, for example, due to a malfunction or a failure of the compressed air supply P. To reactivate the automatic pressure increase user-side intervention is required, for example, pressing a reset Button of the input means 42.

Preferably, the tolerance period "t _T ", which specifies a switching delay between the working mode and the stand-by mode, can be variably predetermined externally. In this way, the switching sensitivity can be adjusted as needed.

Preferably, in the generation of a diagnostic signal or the electrical valve control signal to be taken into account tolerance values individually in the internal control unit 26 can be entered. The user of the compressed air maintenance device 2 can thus adapt the tolerance values and thus the signal output individually to his needs. For entering the tolerance values, the already mentioned input means 42 can be used in particular.

The input means 42 are designed, for example, in the form of an arrangement of keys and / or switches 42a and / or for electronic input. For electronic input, the electrical interface formed by the first communication interface 28 can be used in the exemplary embodiment, which is a bus interface here, the external electronic control device 23 being usable as an information input device. The bus interface can, for example, comply with the I / O link standard.

In the exemplary embodiment, the compressed air maintenance device 2 is equipped with a further, second communication interface 29, which can be used as a diagnostic interface and to which in particular an electronic information reader 46 of the consumer control device 1 is at least temporarily connectable. Such an information reader 46 makes it possible, for example, to read out measured actual information, in particular in conjunction with the assigned reference information, so that it is possible, for example in conjunction with the flow monitoring, to verify at the same time or subsequently at which point of the recorded reference profile an irregularity has occurred. The second communication interface 29 is in particular an Ethernet interface or another digital output. It is located, in particular, on the optional control module 26a.

As a further input means 42 for electronic data input for the purpose of configuration of the system, the compressed air maintenance device 2 of the embodiment contains at least one communication interface, which is designated for better distinction as a third communication interface 30 and to the conveniently a control device and / or a personal computer (PC) can be connected , The at least one third communication interface 30 is in particular an Ethernet interface or another digital input. Preferably, the third communication interface 30 is located on a communication module 30 a of the compressed air maintenance device 2.

Preferably, the compressed air maintenance device 2 is also equipped with a communication interface, which is used for communication between the electronic control unit 26 and one or more other adjacent compressed air maintenance devices of the same or another compressed air treatment device 4. This may be an additional communication interface not shown in the drawing or one of the communication interfaces present in the exemplary embodiment.

It is understood that the compressed air maintenance device 2 may be equipped with any other electrical interfaces for input and / or output of data and / or electrical signals.

When the compressed air maintenance device 2 is realized as a modular unit, it has compact dimensions and can be equipped with the desired functionality in a small space. The existing modules 14a, 25a, 26a and 30a can be easily assembled as needed.

Claims (15)

1. Compressed air conditioning apparatus comprising the following components:

   - an electrically actuable valve device having a feed inlet (16) connectable to a compressed air source (P) and a working outlet (17),

   - an apparatus outlet (7), which is connectable to an external consumer device (A) and connected to the working outlet (17) of the valve device (14) via an outlet passage (22),

   - sensor means (20), at least in the form of a flow sensor (25) for measuring the outlet flow in the outlet passage (22) and of an outlet pressure sensor (24) for measuring the outlet pressure in the outlet passage (22),

   - and an internal electronic control unit (26), which is connected in terms of signal technology both to the valve device and to the sensor means (20) and which is designed to generate an electric valve control signal for the valve device (14) as a function of the state values of the compressed air measured by the sensor means (20),

   characterised in that

   - the valve device is designed as an electrically actuable proportional pressure control valve (14), which is capable of controlling the outlet pressure in the outlet passage (22) to produce different outlet pressure values as a function of the electric valve control signal applied to it, wherein it can be operated both in a working mode in which it controls the outlet pressure to produce a working pressure value and in a standby mode in which it controls the outlet pressure to produce a standby pressure lower than the working pressure value,

   - and in that the electronic control unit is designed such that it

   (a) automatically outputs an electric valve control signal which transfers the proportional pressure control valve (14) from the working mode to the standby mode if the flow sensor (25) detects over a preset or presettable period of time a flow value corresponding to or undershooting a preset or presettable switch-off flow limit value, and that it

   (b) also automatically outputs an electric valve control signal which resets the proportional pressure control valve (14) from the standby mode to the working mode if the flow sensor (25) detects during the standby mode a flow value corresponding to or exceeding a preset or presettable switch-on flow limit value.
2. Compressed air conditioning apparatus according to claim 1, characterised in that the switch-on flow limit value is higher than the switch-off flow limit value.
3. Compressed air conditioning apparatus according to claim 1 or 2, characterised in that the internal electronic control unit (26) is designed such that it automatically deactivates a switch-over function effecting a switch-over from the standby mode to the working mode if the outlet pressure sensor (24) detects an outlet pressure which is reduced to the value of zero.
4. Compressed air conditioning apparatus according to any of claims 1 to 3, characterised in that the outlet pressure sensor (24) is designed to be separate from the proportional pressure control valve (14) or integrated into the proportional pressure control valve (14).
5. Compressed air conditioning apparatus according to any of claims 1 to 4, characterised in that it comprises an apparatus inlet (6), which is connectable to an external compressed air source and connected to the feed inlet (16) of the proportional pressure control valve (14), the sensor means (20) moreover comprising an inlet pressure sensor (31) for measuring the inlet pressure in the inlet passage (11), which is connected in terms of signal technology to the internal electronic control unit (26).
6. Compressed air conditioning apparatus according to any of claims 1 to 5, characterised in that the internal electronic control unit (26) is provided with outputting means (36), which are capable of outputting, in addition to the electric valve control signal for the proportional pressure control valve (14), at least one electric diagnostic signal generated with the collaboration of the sensor means (20), wherein the compressed air conditioning apparatus (2) expediently comprises at least one communication interface (28, 29) for picking up the generated electric diagnostic signal, and wherein the compressed air conditioning apparatus is in particular equipped with visual indicating means (37) and/or audible warning means (38), which can be activated on the basis of an electric diagnostic signal.
7. Compressed air conditioning apparatus according to any of claims 1 to 6, characterised in that the internal electronic control unit (26) is provided with comparator means (35), in which actual information delivered by the sensor means (20) can be compared to reference information stored in memory means (34), wherein the internal electronic control unit (26) is further provided with outputting means (36), which are configured for outputting the electric valve control signal for the proportional pressure control valve (14) and/or another usable electric diagnostic signal as a function of the comparison result of the comparator means (35).
8. Compressed air conditioning apparatus according to any of claims 1 to 7, characterised in that the internal electronic control unit (26) is provided with memory means (34), in which data of various kinds, in particular measurement, control, diagnostic and/or analysis data, can be stored in a volatile or remanent arrangement.
9. Compressed air conditioning apparatus according to any of claims 1 to 8, characterised in that it is designed as a modularly assembled unit, the proportional pressure control valve (14) being a part of a valve module (18), the flow sensor (25) being a part of a sensor module (25a) and the internal electronic control unit (26) being a part of a control module (26a), the compressed air conditioning apparatus expediently having at least one communication module (30a) provided with at least one communication interface (30) connected to the internal electronic control unit (26).
10. Compressed air conditioning apparatus according to any of claims 1 to 9, characterised in that it comprises at least one communication interface (28, 29, 30) connected to the internal electronic control unit (26), to which communication interface (28, 29, 30) an internal and/or external electronic device can be connected, in particular an external electronic control unit (23) and/or an electronic data reading device (46) and/or an electronic data inputting device (47) and/or at least one other electronic device.
11. Compressed air conditioning apparatus according to claim 10. characterised in that at least one communication interface (28) is conceived as a bus interface, and/or in that at least one communication interface (30) is conceived as a digital or analogue input or a digital or analogue output, at least one communication interface (28, 29, 30) being expediently configured as an electromechanical plug-in interface and/or for wireless signal transmission.
12. Compressed air conditioning apparatus according to any of claims 1 to 11, characterised in that it is provided with inputting means (42) for activating and/or influencing and/or parameterising the operating behaviour of the internal electronic control unit (26) and/or the sensor means (20), the inputting means (42) expediently including at least one key (42a) and/or at least one switch (42a) and/or at least one communication interface (28, 30).
13. Consumer control device comprising at least one compressed air conditioning apparatus (2) according to any of claims 1 to 12 and an external electronic control unit (23) connected or connectable thereto.
14. Method for controlling the compressed air supply of a consumer device, characterised in that
    the consumer device (A) is supplied with compressed air through an electrically actuable proportional pressure control valve (14), which comprises a working outlet (17) connected to the consumer device (A), where the compressed air is available at a controlled outlet pressure and outlet flow,
    and in that the outlet flow from the proportional pressure control valve (14) to the consumer device (A) is measured,
    wherein, by suitable electric selection of the proportional pressure control valve (14), the outlet pressure is automatically controlled to produce a standby pressure value lower than the working pressure value if the outlet flow has, across a preset or presettable period of time, a value corresponding to or undershooting a preset or presettable switch-off flow limit value, and wherein, by suitable electric selection of the proportional pressure control valve (14), the outlet pressure is automatically controlled to produce a working pressure value higher than the standby pressure value if the outlet flow has a value corresponding to or exceeding a preset or presettable switch-on flow limit value.
15. Method according to claim 14, characterised in that its execution involves a compressed air conditioning apparatus comprising the following components:

    - the electrically actuable proportional pressure control valve (14) having a feed inlet (16) connectable to a compressed air source (P) and the working outlet (17),

    - an apparatus outlet (7) connectable to the external consumer device (A) and connected to the working outlet (17) of the proportional pressure control valve (14) via an outlet passage (22),

    - sensor means (20), at least in the form of a flow sensor (25) for measuring the outlet flow in the outlet passage (22) and of an outlet pressure sensor (24) for measuring the outlet pressure in the outlet passage (22),

    - and an internal electronic control unit (26), which is connected in terms of signal technology both to the proportional pressure control valve (14) and to the sensor means (20) and which is designed to generate an electric valve control signal for the valve device (14) as a function of the state values of the compressed air measured by the sensor means (20),

    wherein the proportional pressure control valve (14) is capable of controlling the outlet pressure in the outlet passage (22) to produce different outlet pressure values as a function of the electric valve control signal applied to it, wherein it can be operated both in a working mode in which it controls the outlet pressure to produce a working pressure value and in a standby mode in which it controls the outlet pressure to produce a standby pressure lower than the working pressure,
    wherein the proportional pressure control valve (14) is further switched automatically from the working mode to the standby mode by means of an electric valve control signal generated by the internal electronic control unit (26) if the flow sensor (25) detects over a preset or presettable period of time a flow value corresponding to or undershooting a preset or presettable switch-off flow limit value,
    and wherein the proportional pressure control valve (14) is automatically reset from the standby mode to the working mode by means of an electric valve control signal generated by the internal electronic control unit (26) if the flow sensor (25) detects during the standby mode a flow value corresponding to or exceeding a preset or presettable switch-on flow limit value.

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