The invention relates to an adapter device and a method for regulating a control current of a device actuating the magnetic force of a valve, in particular in the form of a coaxial valve.
From DE 10 2011 010 938 A1, a magnetically directly controlled valve of coaxial design is known, which is controlled by means of an electronic system, which detects and evaluates the applied voltage and current flow at any time of valve actuation, which flows through a solenoid coil arranged in the valve, which serves as a magnetic force actuator for a magnet keeper, which is used to open and close the actuated valve by means of a valve piston axially movable in opposite directions in a valve housing.
The electronics can change the current and voltage values applied to the known solenoid coil, which are used for actuating the coil, in analog or digital form. In this way, the applied voltage or the current flowing through the solenoid coil can be altered in an analog manner or regulated in a digital manner, for instance by means of pulse width modulation. In the known solution, the magnetic force actuator in the form of the solenoid coil is, for the purpose of energizing it, connected to a connector part, which is directly connected externally to the valve housing, permanently wired to the solenoid coil and therefore connected in a non-interchangeable manner to the coil actuation of the electronics, which has a corresponding signal input on its input side in addition to the power supply.
In this way, the pressure-compensated, well-known coaxial valve can be operated at very low electrical power and can be regulated continuously regarding the valve position; only the connector part in conjunction with the upstream electronics is always adapted to a certain valve type in terms of its design and technical layout and therefore cannot be used modularly for different types of valves and valve types. Different manufacturers also use different types of standardized connector parts to actuate the individual, different valve types, also in the form of coaxial valves, having different flow characteristics, i.e., in order to satisfy the demands of every type of plug and valve, independent electronics must be designed and connected upstream of the connector part.
Based on this state of the art, the invention addresses the problem of improving the known solution.
An adapter device having the features of claim 1 in its entirety solves this problem. The adapter device according to the invention is used to regulate a control current of a magnetic force actuator of a valve, in particular in the form of a coaxial valve, having a housing, into which the hardware and the software for regulating the control current of the magnetic force actuator of the valve are integrated and which has a connection device for detachably connecting to the valve and a further connection device for detachably connecting to a connector part, which can be used to supply the adapter device with current at least externally; however, measuring devices, data loggers and evaluation devices can also easily be connected.
In the solution according to the invention, a kind of intermediate plug is realized via the adapter device based on integrated hardware and software, which intermediate plug can be installed between the relevant valve or coaxial valve and its solenoid coil and the actual standard connector part, which is specified by the manufacturer in a space-saving, modularly exchangeable manner.
In this way, it is also possible to easily retrofit existing fittings in the form of valves used in fluid systems, such as coaxial valves. Because the software can be individually implemented in the hardware of the adapter device, complex control and evaluation processes for actuating the connected valve of a given valve type can be obtained directly on site. However, it is also possible to “activate” only individual functions of the software in a particularly cost-effective manner, for instance to dampen closing impacts, which can occur regularly and at a higher intensity during the operation of coaxial valves in connected fluidic systems, or a so-called “condition monitoring” of the valve can be performed by means of the implemented software, without the need for any additional measurement and evaluation equipment being set up externally in a control cabinet or on the valve itself, which regularly requires the use of a more complex overall control system and software. The “island solution” with its integrated software implementation on site, i.e. directly on the valve, has shown that the control and regulation effort can be reduced in a targeted manner.
Without having to make any changes to the fluid system to which the valve is connected, the user can retrofit an existing system using the adapter device in accordance with the invention in an advantageous way without any great expenditure in terms of equipment. In particular, the user of such systems will welcome the fact that he can continue to use the standardized connector parts he purchased and used by simply plugging them into the connection device of the adapter device and in this respect adhere to the wiring concept he introduced. This is without parallel in the prior art.
Furthermore, according to the configuration of features of patent claim 18, the above problem is also solved by a method for regulating a control current of a magnetic force actuator of a valve, such as a coaxial valve, which has at least one coil that is equipped with the adapter device according to the invention described above.
In a preferred exemplary embodiment, the connection device has means for connecting the detachable mechanical and electrical connection of the adapter device to the valve, in particular for connecting it to the magnetic coil of the magnetic force actuator of the valve, and the further connection device has means for mechanically and electrically connecting the adapter device to the connector part in a detachable manner. For this purpose, plug and socket parts, which can be brought into engagement with each other in the usual, in particular standardized, form, having female and male contact parts, are used for the detachable mechanical and electrical connection.
The hardware may comprise a computing unit, in particular a microcontroller, on which a method for regulating the control current is implemented in the form of software. The use of a microcontroller as a computing unit has the advantage that microcontrollers are inexpensive, use little energy and can be installed in a space-saving manner.
All components of the hardware can be arranged on a printed circuit board and are electrically connected to each other using conductive tracks, as described below. The circuit board can be designed to be mounted to the housing of the adapter device.
Furthermore, the hardware may include at least one rotary switch to parameterize the adapter device, in particular the software implemented on the computing unit. The rotary switch is electrically connected to the computing unit, in particular to a sequencer software-implemented on the computing unit. The rotary switch is preferably designed as a coding switch. Coding switches are characterized by being very reliable and easy to operate.
Preferably three rotary switches are provided. A first rotary switch is provided for setting an operating mode of the adapter device, such as an operating mode reducing the power of the magnetic force actuator or an operating mode having the function of damping the closing impact of the valve or an operating mode in the form of a service mode. If the adapter device is used for the first time in combination with an individual valve, the former has to be adapted to this valve by means of a parameterization of the software parameters adapted to the individual valve. For this purpose, among other things, a second rotary switch is provided for setting the nominal size (DN10 to DN40) of the individual valve, which refers to the free connection cross-sections of the valve. A third rotary switch is provided for adjusting the switch-on and switch-off speed of the valve. It is particularly preferred that at least the second and the third rotary switch have sixteen switching positions, permitting the selection of sixteen options for setting different nominal sizes of the valve via the second rotary switch and sixteen combinations of different switch-on and switch-off durations can be selected via the third rotary switch.
The hardware may further comprise at least one display means for indicating a faulty operating state of the valve or for indicating the switching position of a valve part of the valve. The display means can be controlled by the computing unit and connected to the sequencer, which is software-implemented on the computing unit. The display means can be arranged in such a way that it is visually or acoustically perceptible from outside the adapter device for an operator of the adapter device. It is also conceivable that the sequencer transmits an electrical signal via a data line to an external main computer unit, i.e. one that is located remotely from the valve, the adapter device and the connector part, from which the faulty operating state of the valve, the switching position of the valve part of the valve or further information of the adapter device or the valve can be obtained. It is also conceivable that such a signal is transmitted wirelessly between the sequencer and the main computer unit, in particular using Bluetooth technology.
The hardware may also have an output stage, which is connected on the input side to the computing unit, more specifically to an output of a current regulator software-implemented on the computing unit.
The output stage is supplied with a pulse-width modulated (PWM) signal from the current regulator to regulate the control current. The software computes the duty cycle of the PWM signal, which indicates the percentage of the maximum power that the pulse-width modulated signal feeds to the output stage. By means of a pulse-width modulated signal, the output stage can be operated in the switching mode, in which its transistors are either in a conducting or isolating mode. In contrast to the intermediate states used in conventional class A, class B or class AB amplifiers, these two modes have relatively little power dissipation in linear operation, which means that the output stage, which is preferably in the form of a class D amplifier, is low-energy.
The output stage essentially has a half-bridge of, preferably two, transistors in combination with a suitable driver module. An output stage designed as a half-bridge has a higher overall efficiency than an output stage designed as a full bridge, having for instance four transistors, due to lower switching losses. On the output side, the output stage can be connected to a coil of the magnetic force actuator via the connection device. The energy consumption of the valve can be reduced by emitting a pulse-width modulated signal, namely the control current or the control voltage, of the output stage for actuating the coil of the magnetic actuating device.
The hardware can additionally comprise a current detection device for determining an actual value of the control current of the coil, which is connected to the computing unit on the output side, in particular to a resistance value computing module and/or to an induction voltage computing module and/or to the current regulator and/or to the sequencer, which are each software-implemented on the computing unit.
The current detection device can have a shunt resistor, which can be connected to the coil of the magnetic force actuator via the connection device in such a way that the current through the coil also flows through the shunt resistor, across which the voltage drop is measured to determine the actual value of the control current. The control current is the supply current of the magnetic force actuator flowing into the magnetic force actuator. The resistance value of the shunt resistor is preferably in the milliohm range or smaller. The advantage of measuring current using a shunt resistor is that it is inexpensive and space saving, and it renders current measurement easy. However, the use of a Hall-effect current sensor for measuring the control current is also conceivable.
The hardware can also include a voltage detection device for determining the actual value of the control voltage of the magnetic force actuator, by means of which the actual value of the control voltage of the coil of the magnetic force actuator can be tapped on the input side using the connection device and which, on the output side, is connected to the computing unit, specifically to the resistance value computing module and/or to the induction voltage computing module and/or to the sequencer, which are each software-implemented on the computing unit. The control voltage is the supply voltage of the magnetic force actuator applied to the magnetic force actuator.
For amplifying the actual value of the control current, the current detection device may have an amplifier, the gain of which is adapted to an input-side analog/digital converter of the computing unit for processing the actual value of the control current. Alternatively or additionally, the voltage detection device for amplifying the actual value of the control voltage can have a further amplifier, the gain of which is adapted to another input-side analog/digital converter of the computing unit for processing the actual value of the control voltage.
The software implemented on the computing unit may comprise a software-implemented resistance value computing module for determining the value of the resistance of the coil of the magnetic force actuator, one input of which is connected to an output of the voltage measuring means and another input of which is connected to an output of the current determining means and, on the output side, is connected to an input of a software-implemented induction voltage computing module. The resistance value computation module computes the resistance of the coil, which alters depending on the temperature. For purposes of computation, the valve section is assumed to be stationary.
One input of the software-implemented induction voltage computation module for determining the actual value of the induced voltage of the coil of the magnetic force actuator is connected to an output of the resistance value computation module, another input is connected to the output of the voltage determination device and another input is connected to the output of the current determination device. On the output side, the induction voltage computation module is connected to a voltage regulator software-implemented on the computation unit.
The software may also include a software-implemented sequencer for processing predetermined control signals for actuating the valve and/or a predetermined parameterization of the adapter device, which can be connected to the external main computing unit via the further connection device and via the connector part for communication, for instance by means of the SDCI standard (single-drop digital communication interface for small sensors and actuators, standard IEC TR 61131-9), better known as the IO-Link communication system. The main processing unit transmits control signals to the sequencer system to regulate the valve, among other things.
On the input side, the at least one hardware rotary switch and/or the output of the current detection device and/or the output of the voltage detection device are connected to the sequencer unit and on the output side, the latter is connected to a voltage regulator for transmitting set values of the induced voltage to a voltage regulator or to a current regulator for transmitting set values of the control current, which are each software-implemented on the computing unit.
The software can also include the software-implemented voltage regulator, which is connected on the input side to the sequencer for transmitting set values of the induced voltage and to the voltage computation module for transmitting actual values of the induced voltage, and which is connected on the output side to an input of the current regulator if necessary. The voltage regulator regulates the induced voltage of the coil based on the set value and the determined actual value of the induced voltage by emitting a signal, which is used to derive the set value of the control current.
The control voltage is the supply voltage of the magnetic force actuator applied to the magnetic force actuator. However, the induced voltage of the coil, which drops directly across the coil, deviates from the control voltage for a certain time when the control voltage or the control current change. Thus a change in the control voltage or current results in a change in the magnetic flux through the coil. According to Lenz's law, the change in magnetic flux induces a voltage in the coil, which influences the value of the control voltage. As a result, when the control voltage changes positively, i.e. a voltage increase, the control current only gradually increases to its final value. In the case of a negative change in the control voltage, i.e. a voltage decrease, the current can still flow if a corresponding circuit remains established.
A voltage can be induced in the coil when the air gap closes because the magnetic circuit around the coil, through which the current flows aims at reducing its magnetic resistance by, for instance, closing an air gap. The control voltage is only indirectly influenced by the current regulator.
The software can also include the software-implemented current regulator, one input of which is connected to the sequencer or to the output of the voltage regulator for transmitting set values of the control current and the other input of which is connected to the current detection device. The current regulator regulates the control current to the specified setpoint value.
The software may also include a software-implemented switch that can be controlled by the sequencer and that connects one input of the current regulator to either the sequencer or the output of the voltage regulator.
The software may include other software-implemented functions in addition to the function of regulating the control current of the coil of the magnetic force actuator. Conceivable, for instance, is a function for reducing the current of the coil, in particular in continuous operation; and/or a function for moving the valve part at a predeterminable speed when switching on and off; and/or a function for detecting the switching state of the valve; and/or a function for monitoring valve parameters, such as the switching cycles, the lengths of the on/off intervals, the pick-up/drop-out current and/or the coil resistance.
According to claim 18, the subject matter of the invention is also a method for regulating a control current of a magnetic force actuator of a valve, which has at least one coil, which can be used to operate the adapter device according to any one of the claims 1 to 17.
The method comprises the following process steps:
The setpoint value of the control current can be predetermined by parameterization or determined according to the further process steps listed below:
When using the setpoint value of the control current determined according to the preceding process steps for the regulation of the control current, the control current can be regulated particularly accurately, in particular due to the inclusion of the induced voltage of the coil.
Below, the adapter device according to the invention, which can be operated by the method according to the invention in the form of software, will be explained in more detail with reference to the drawing. In the figures, in general view, not to scale,
As shown in
The standard connector part 4 shown in
As shown in
In at least one open position not shown in more detail in the figures, in which the valve part 26, controlled by a magnetic force actuator 32, disengages from the valve closing part 30 in its axial direction of travel against the action of the compression spring 28 and lifts off from the latter, the fluid path through the valve 6 between the fluid inlet E and the fluid outlet A along the predeterminable flow path is opened for the fluid.
The magnetic force actuator 32 shown in
A hardware H for regulating the control current is of the magnetic force actuator 32 of the valve 6 is integrated into the adapter housing 8, which device has a printed circuit board—not shown in the figures—on which essentially—see
The sequencer 62 is connected to the external main computing unit not shown in the figures in a communicating manner via the further connection device 18 and via the connector part 4. The IO-Link communication system is provided for communication. The sequencer 62 receives predetermined control signals for actuating the valve 6 from the main processing unit, in particular set values of voltage and current and a predetermined parameterization of the adapter device, and processes these data. In addition, upon request, the sequencer 62 transmits information about the adapter device or the valve 6 to the main processing unit.
In addition to the parameterization by means of the external main computer unit not shown in the figures, the three rotary switches 44, 70, 72 in the form of coding switches are connected to the sequencer 62 (see
Furthermore, a display means 56 in the form of a lamp, e.g. an LED, is connected to the sequencer 62 (see
The current detection device 50 (see
The voltage detection device 52 (see
The resistance value computation module 58 (see
The induction voltage computation module 60 (see
The voltage regulator 64 (see
The current regulator 66 (see
For the sake of simplicity, the switch 68 is shown in
The current regulator 66 generates a pulse width modulated signal PWM and transmits it to the output stage 48 (see
Number | Date | Country | Kind |
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10 2017 008 944.2 | Sep 2017 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/075095 | 9/17/2018 | WO | 00 |