Flow controller, method for controlling a flow in a fluid channel of a flow controller, and computer program product

Abstract

The invention relates to a flow controller (11) comprising: a fluid channel (15) that has a valve seat (23) and a throttle section (18) and a valve element (22), a valve drive (21) for initiating a movement being assigned to the valve element (22); a first pressure sensor (27) that is connected to a first measurement connection (25) and a second pressure sensor (28) that is connected to a second measurement connection (26), the first pressure sensor (27) and the second pressure sensor (28) being electrically connected to a processing device (31) that determines an actual flow value in the fluid channel (15) from the sensor signals acquired by the pressure sensors (27, 28) and comprises a fluid flow controller (41) that is designed to provide the valve drive (21) with an actuating signal for the purpose of controlling the actual flow value to a target flow value. The processing device (31) is designed to output an error message if the first sensor signal exceeds a predefined first threshold value and / or if the second sensor signal exceeds a predefined second threshold value.

Description

[0001] Flow controller, method for regulating a flow in a fluid channel of a flow controller, and computer program product

[0002] The invention relates to a flow controller for providing a predefinable fluid flow. Furthermore, the invention relates to a method for controlling a flow in a fluid channel of a flow controller and a computer program product.

[0003] The applicant's product range includes the proportional flow control valve VEMD, which allows for proportional control and metering of the flow of air or inert gases.

[0004] The object of the invention is to provide a flow controller with which any changes that may occur in a fluid consumer connected to the flow controller can be detected.

[0005] This problem is solved for a flow controller of the type mentioned above by the flow controller having a housing in which a fluid channel extends from an inlet port to an outlet port, wherein the fluid channel has a valve seat and a throttle section, wherein a valve element is movably mounted in the housing between a closed position for the valve seat and an open position for the valve seat, wherein a valve actuator is arranged in the housing which is designed to initiate a movement on the valve element, and wherein a first pressure sensor is provided which is connected to a first measuring port arranged between the inlet port and the throttle section, and wherein a second pressure sensor is provided which is connected to a second measuring port arranged between the throttle section and the outlet port.wherein the first pressure sensor and the second pressure sensor are electrically connected to a processing device which determines a flow rate in the fluid channel from first sensor signals of the first pressure sensor and from second sensor signals of the second pressure sensor and which comprises an algorithm or an electronic circuit referred to as a fluid flow controller, wherein the fluid flow controller is configured to provide a control signal to the valve actuator for regulating the flow rate to a setpoint flow rate, and wherein the processing device is configured to output an error message if the first sensor signal exceeds a predetermined first threshold and / or if the second sensor signal exceeds a predetermined second threshold.

[0006] In principle, the flow controller is based on a proportional valve, in which a valve element can be moved relative to a valve seat by a valve actuator in a predefined manner depending on a control signal. In a closed position, the valve element closes the valve seat formed in a fluid channel, thus preventing fluid flow through the fluid channel. Furthermore, in an open position, the valve element releases the valve seat, thereby allowing fluid flow through the fluid channel. A valve actuator is provided for the movement of the valve element between the closed and open positions. This actuator is motion-coupled with the valve element and can be controlled by an electrical control signal.For example, the valve actuator is designed as a solenoid actuator or as a piezo actuator and is designed for free positioning of the valve element between the closed position and the open position, so that a flow cross-section of the fluid channel in the area of ​​the valve seat can be variably adjusted and thus an influence on the volume flow (volume per time) and thus also on the mass flow (mass per time) that flows through the fluid channel can be taken.

[0007] The control signal is provided by a processing unit that is electrically coupled to the valve actuator and is, for example, a microcontroller or microprocessor. The processing unit is designed to execute a computer program stored in its memory. Specifically, the processing unit is configured to process input signals, such as sensor signals provided by pressure sensors, and to output control signals calculated by the computer program based on these input signals.The control signals can be supplied directly to the valve actuator, provided the actuator has its own power supply and is capable of processing an incoming control signal and converting it into movement of the valve actuator and the coupled valve element. Alternatively, the control signal from the processing unit is supplied to an electrical output stage, which can be integrated into the processing unit, and this electrical output stage provides the electrical energy required to control the valve actuator.

[0008] As an example, the valve actuator is designed as a piezoelectric actuator, in which a strip-shaped piezoelectric element can be adjusted between different bending positions by applying an electrical control voltage. It is particularly preferred that the valve element, as a rubber-elastic sealing element, is applied directly to a surface of the piezoelectric element, also known as a piezo bender, and can be moved between a closed position, sealing against a valve seat, and a release position located away from the valve seat by means of different electrical control signals.It is particularly preferred that the control signal provided by the processing unit is converted by a high-voltage output stage, which is electrically connected to the processing unit, into a high-voltage electrical signal with which the piezoelectric element can be controlled. A typical control voltage for the piezoelectric element lies in the range of 200 volts to 500 volts.

[0009] The actuating movement of the valve drive and the resulting movement of the valve element between the closed and open positions allow the volumetric flow rate, and thus also the mass flow rate, flowing through the fluid channel to be adjusted within a range whose upper limit depends on the maximum available volumetric or mass flow rate. This assumes that the fluid channel extends from the inlet port, located on an outer surface of the (flow regulator) housing and which can be connected, for example, to a fluid source, particularly a compressed air source or an inert gas source, to an outlet port, which can be connected, for example, to a fluid consumer. The fluid channel can be configured in the housing as a bore.The fluid channel within the housing can also be designed as a pipe or hose in certain areas.

[0010] The fluid consumer connected to the output port of the flow controller can be a fluid drive designed to convert fluid energy into kinetic energy, as is the case, for example, with a pneumatic cylinder or a compressed air motor.

[0011] Preferably, the fluid consumer is a process chamber or a storage chamber that requires a fluid supply to maintain a predetermined atmosphere within the enclosed volume. Such a process or storage chamber is used, for example, in semiconductor manufacturing. There, process steps for wafers are carried out in process chambers that require a supply of process gas to the chamber. Furthermore, wafers are temporarily stored between different process steps in storage chambers, particularly storage boxes, where an inert gas atmosphere, for example, an atmosphere with a defined nitrogen concentration, must be maintained. This is ensured by a controlled nitrogen supply to the storage chamber, which can be implemented using the inventive flow controller.The fluid line, which is typically provided for the fluidically communicating connection between the flow controller and the process chamber or storage chamber, is also preferably attributed to the fluid consumer. In order to control the flow in the fluid channel, it is necessary to determine a current flow value in the fluid channel. For determining the current flow value, the flow controller includes a first pressure sensor, which is arranged at a first measuring port and is electrically connected to the processing equipment to provide a first sensor signal to the processing equipment. Furthermore, for acquiring the current flow value, the flow controller includes a second pressure sensor, which is arranged at a second measuring port and is electrically connected to the processing equipment to provide a second sensor signal to the processing equipment.The first measuring connection is located upstream of a throttle section formed in the fluid channel, i.e., between the inlet connection and the throttle section. Furthermore, the second measuring connection is located downstream of the throttle section, i.e., between the throttle section and the outlet connection.

[0012] Preferably, the first and second pressure sensors are relative pressure sensors, each designed to detect an overpressure or underpressure at the respective measuring port relative to the environment of the flow controller. Alternatively, the first and second pressure sensors can each be designed as absolute pressure sensors. In either case, determining the actual flow rate in the fluid channel requires a first pressure value at the first measuring port and a second pressure value at the second measuring port, whereby these first and second pressure values ​​can be determined using either relative pressure sensors or absolute pressure sensors.

[0013] The throttled section exhibits a significantly increased flow resistance for the fluid compared to the rest of the fluid channel. This increased flow resistance can be achieved, for example, by a nozzle or orifice arranged in the fluid channel, but in particular by a turbulence throttle arrangement formed from several orifices. By way of example, it is provided that the fluid channel, away from the throttled section and at maximum distance between the valve seat and the valve element (fully open valve), has a substantially constant cross-section and thus also a substantially constant flow resistance. In the region of the throttled section, however, the local constriction of the fluid channel results in a flow resistance that is at least twice, preferably at least five times, and in particular at least ten times, the flow resistance of the rest of the fluid channel.

[0014] Provided the processing unit has access to the first sensor signal from the first pressure sensor and the second sensor signal from the second pressure sensor, the actual flow rate, and thus the volumetric flow rate and the mass flow rate, can be calculated from these two sensor signals. For this calculation, the computer program running in the processing unit first calculates a first pressure value from the first sensor signal and a second pressure value from the second sensor signal. Subsequently, using an algorithm and taking into account the characteristics of the throttle section, the computer program can calculate an actual flow rate from the first and second pressure values. This actual flow rate can be output as a volumetric flow rate or as a mass flow rate, if necessary after further calculations.For example, to determine the volumetric flow rate and / or the mass flow rate, the temperature of the gas flowing through the flow controller must also be determined. Additionally or alternatively, the density of the gas flowing through the flow controller can be included. The actual flow rate is then provided to another algorithm in the computer program, also known as the fluid flow controller. This fluid flow controller calculates a flow deviation from the actual flow rate and a predefined flow setpoint, which is stored, in particular, in the processing unit. From this, it calculates the control signal, which represents the change in the position of the valve element required to minimize the flow deviation.

[0015] In practical use of a flow regulator to supply fluid to a fluid consumer, a situation may arise where the position of a connecting line between the flow regulator and the fluid consumer—which may be a fluid hose typically with a small cross-section and a long length—changes, potentially altering the flow resistance of this connecting line, particularly increasing it. This is especially true if the connecting line is sharply bent or even kinked. This can lead to a situation where the fluid flow through the flow regulator becomes backed up in the connecting line, causing a pressure increase at the two measuring ports because the fluid can no longer flow properly to the fluid consumer.With such a pressure increase at the second measuring port, the pressure drop across the throttle section initially decreases. This reduces the calculated flow rate value in the processing unit, and the flow deviation increases. Consequently, the fluid flow controller adjusts the control signal so that the valve actuator moves the valve element further into the open position to reduce the flow deviation between the actual and setpoint flow values. If a pressure increase occurs in the flow controller that exceeds the measuring range of at least one of the two pressure sensors, the sensor signal of the respective pressure sensor no longer represents the actual pressure value at the respective measuring port.Accordingly, a self-reinforcing malfunction of the flow controller can occur, in which the intended fluid supply to the fluid consumer is no longer guaranteed.

[0016] To communicate this malfunction to a user and / or to a control device superior to the flow controller, in particular a machine control or a process control system, the processing device is designed to provide an error message if the malfunction occurs. To detect the malfunction, the processing device is designed to monitor the first sensor signal provided by the first pressure sensor and / or the second sensor signal from the second pressure sensor. As soon as the first sensor signal exceeds a predefined first threshold and / or as soon as the second sensor signal exceeds a predefined second threshold, it is assumed that the malfunction has occurred.The first and / or second threshold values ​​are selected such that they are not exceeded during proper operation of the flow controller and the connected fluid consumer. An exceedance of the first and / or second threshold value only occurs if there is an impairment of the fluid flow downstream of the throttle section in the form of additional, undesired throttling. Preferably, the respective (first or second) predefinable threshold value corresponds to the maximum pressure that can be determined by the respective (first or second) pressure sensor. Particularly preferably, the respective (first or second) predefinable threshold value is set by a defined absolute or percentage amount below this maximum pressure that the respective (first or second) pressure sensor can detect.

[0017] The error message can be provided by the flow controller to a higher-level control unit electrically connected to the flow controller in the form of an analog or digital signal, in particular a digital high signal. Additionally or alternatively, the error message can be output directly by the flow controller as a visual and / or audible signal.

[0018] Advantageous further developments of the invention are the subject of the dependent claims.

[0019] It is advantageous if the processing equipment is designed to gradually reduce the target flow rate when the first sensor signal exceeds the predetermined first threshold and / or the second sensor signal exceeds the predetermined second threshold, until the actual flow rate is reached by influencing the valve actuator, at which the first sensor signal is below the predetermined first threshold and / or the second sensor signal is below the predetermined second threshold. This measure is intended to ensure that, even in the event of a disruption to the fluid supply to the fluid consumer, a controlled and traceable fluid supply to the fluid consumer is maintained until this disruption is rectified.This assumes that the fluid consumer, which may be a process chamber or a storage chamber in which a predetermined gas atmosphere is to be maintained, has a certain tolerance to changes in the gas atmosphere and that, at least within a predetermined time period, which begins with the provision of the error message by the processing equipment, no negative effects will occur on the processes taking place in the gas atmosphere or on the objects stored in the gas atmosphere, provided that a gas supply – even if reduced – is available within this time period and the impairment of the fluid supply is rectified within this time period.Accordingly, the processing unit is designed to reduce the flow setpoint until a fluid flow through the flow controller and to the fluid consumer is established at which the first sensor signal no longer exceeds the predefined first threshold and / or the second sensor signal does not exceed the predefined second threshold. This reduction of the flow setpoint, which can be carried out, for example, in percentage or absolute steps, reduces the flow deviation from the actual flow value, which has erroneously dropped to an incorrectly low level due to the impairment of the fluid supply.It follows that the fluid flow controller provides a control signal that leads to a reduction in the valve opening determined by the valve actuator and valve element, so that, despite the increased flow resistance downstream of the throttle section, pressure values ​​are again established at both measuring ports, allowing for a reliable determination of the actual flow rate. The criterion for a successful reduction of the setpoint flow rate is therefore the first sensor signal, which falls below the predefined first threshold, and additionally or alternatively, the second sensor signal, which falls below the predefined second threshold.

[0020] Preferably, the processing device includes, in addition to the fluid flow controller, a fluid pressure controller designed as an algorithm or electronic circuit, which is configured to limit a first pressure value determined from the first sensor signal to a first maximum pressure value and / or to limit a second pressure value determined from the second sensor signal to a second maximum pressure value. The fluid pressure controller is preferably implemented as a software module (algorithm) within the computer program executed in the processing device. The fluid pressure controller operates in parallel with the fluid flow controller and serves to monitor the first pressure value and / or the second pressure value.The fluid pressure regulator's influence on the control signal provided by the processing unit to the valve actuator is only intended if a fluid pressure, in particular the second fluid pressure, exceeds a predetermined maximum pressure value, especially a second maximum pressure value. This maximum pressure value can, for example, be identical to the predetermined second threshold value.

[0021] It is advantageous if the valve seat is arranged between the inlet port and the throttle section. The valve seat, together with the valve element and the valve actuator, forms a fluid valve that provides adjustable throttling for the fluid channel. By arranging the valve seat upstream of the throttle section, the fluid pressure supplied at the inlet port by a fluid source, as well as the resulting fluid volume flow or mass flow rate, is already throttled by the fluid valve to such an extent that an advantageous adaptation to the fluid demand of the fluid consumer can be ensured.Due to the non-adjustable, flow-dependent throttling effect of the throttle section, the pressure values ​​at the first measuring port and at the second measuring port are each kept at a level that allows for the most accurate possible determination of the actual flow rate.

[0022] In a further development of the invention, it is provided that the first measuring port is arranged between the valve seat and the throttle section. This ensures that the first sensor signal reflects as accurately as possible the pressure level that exists immediately before the throttle section, thus enabling the most accurate possible determination of the flow rate.

[0023] In a further embodiment of the invention, it is provided that the valve element and the valve seat together with the valve actuator form a fluid valve from the group: directly controlled seat valve, directly controlled spool valve, fluidly piloted seat valve, fluidly piloted spool valve.

[0024] In a poppet valve, the valve element is designed to move along an axis of movement and to come into sealing contact with the valve seat, which is, for example, designed as an annular surface arranged in a plane oriented transversely to the axis of movement. The poppet valve is thus designed for an axial sealing effect. In a slide valve, the valve element moves along an axis of movement within a valve bore, with at least two connecting bores opening into the valve bore, which are oriented, in particular, transversely to the axis of movement. The valve element, also referred to as a valve slide, has a seal projecting radially outwards beyond the valve slide, which can, for example, be implemented as an O-ring oriented coaxially to the axis of movement and is designed for a radial sealing effect with a portion of the valve bore.

[0025] In a direct-controlled valve, the valve element is set in motion directly by an electromechanical valve actuator, which may be, for example, a magnetic actuator, a piezo actuator, or an electric geared motor, depending on the control signal.

[0026] In a fluidically pilot-operated valve, the valve element is set in motion by a pressurized fluid, in particular compressed air or inert gas, whereby the pressurized fluid is supplied via an electrically controlled pilot valve which can be controlled with the control signal.

[0027] The invention solves the problem by a method for controlling a flow in a fluid channel of a flow controller, comprising the following steps: determining a first fluid pressure at a first measuring port of a fluid-filled fluid channel, wherein the first measuring port is arranged between an inlet port of the fluid channel and a throttle section formed in the fluid channel; determining a second fluid pressure at a second measuring port, which is arranged between the throttle section and an outlet port of the fluid channel; calculating an actual flow value present in the fluid channel from the first fluid pressure and the second fluid pressure in a flow computer of a processing device; providing a control signal from the processing device to a valve actuator, which influences the position of a valve element depending on the control signal.which is assigned to a valve seat arranged in the fluid channel, wherein the control signal is calculated by a fluid flow controller formed in the processing unit, which minimizes a flow deviation between the actual flow value and a target flow value, and wherein the processing unit provides an error message if the first fluid pressure exceeds a predetermined first threshold value and / or if the second fluid pressure exceeds a predetermined second threshold value.

[0028] In a further development of the process, it is provided that the processing device gradually reduces the target flow rate until, through the influence on the valve actuator and the resulting change in the position of the valve element, an actual flow rate is established at which the first sensor signal is below the specified first threshold and / or at which the first sensor signal is below the specified first threshold.

[0029] In a further embodiment of the method, it is provided that a fluid pressure regulator of the processing device monitors the first fluid pressure and changes the control signal provided by the fluid flow regulator if the first fluid pressure exceeds a predetermined first threshold value and / or that the fluid pressure regulator of the processing device monitors the second fluid pressure and changes the control signal provided by the fluid flow regulator if the second fluid pressure exceeds a predetermined second threshold value.

[0030] The task of invention is also solved by a computer program product with a computer program, wherein the computer program includes software means trained to execute the procedure according to the invention, if the computer program is executed by a microprocessor or microcontroller.

[0031] An advantageous embodiment of the invention is shown in the drawing. This shows:

[0032] Figure 1 is a purely schematic overview of a process system comprising a gas source, a flow regulator, and a process chamber.

[0033] Figure 2 is a purely schematic representation of a processing unit of the flow regulator shown in Figure 1.

[0034] A process system 1 shown in Figure 1 can be used, for example, in the production of semiconductor components and comprises a gas source 2, a flow controller 11, and a process chamber 5. For illustrative purposes, semiconductor components (not shown in detail) are placed in the process chamber 5 and exposed to process gas supplied by the gas source 2 and fed in via the flow controller 11. To ensure reproducible gas exposure of the process chamber 5, the process gas is supplied to the process chamber 5 at a predetermined flow rate. The task of the flow controller 11 is therefore to control this process gas flow rate so that the required process gas flow is always supplied to the process chamber 5.

[0035] For this purpose, the gas source 2 is connected via a supply line 3 to an inlet port 13 of the flow regulator 11, the inlet port 13 being located on an outer surface of a housing of the flow regulator 11. The inlet port 13 forms the beginning of a fluid channel 15, which extends through the housing 12 and terminates at an outlet port 14. Both the inlet port 13 and the outlet port 14 are, purely by way of example, designed as hose couplings to which the supply line 3, designed as a fluid hose, and an outlet line 4, also designed as a fluid hose and connected to the process chamber 5, can be connected.

[0036] The fluid channel is exemplarily divided into several fluid channel sections 16, 17, 18 and 19, wherein functional components described in more detail below are arranged at the respective, unspecified interfaces between the fluid channel sections 16 to 19.

[0037] A fluid valve 37, which is a purely exemplary fluid pilot-operated proportional valve, is arranged between the first fluid channel section 16, which is connected to the inlet port 13, and the second fluid channel section 17. The fluid valve 37 comprises an electrically actuated pilot valve 20, which acts on a fluid valve actuator 21. The actuator 21, in turn, can cause movement of a valve element 22 between a closed position, as shown in Figure 1, and an open position (not shown). The position of the valve element 22 between the closed position and the open position f is freely selectable, so that the flow cross-section f of the valve seat 23 (shown only indicatively) provided by the fluid valve 37 can be freely adjusted.A return spring 24 acts against the valve actuator 21, so that the fluid valve 37 is, purely as an example, a normally closed proportional valve.

[0038] The pilot valve 20 is connected via a control line 32 to a processing device 31 described in more detail below, which provides control signals for the pilot valve 20 in order to influence the free flow cross-section at the valve seat 23 of the fluid valve 37.

[0039] A first measuring port 25 is arranged between the second fluid channel section 17 and the third fluid channel section 18, to which a first pressure sensor 27 is connected. The first pressure sensor 27 is designed to convert a fluid pressure present at the first measuring port 25 into an electrical sensor signal and is electrically connected to the processing device 31 via a first sensor line 29.

[0040] A third fluid channel section 18, also referred to as a throttle section, extends between the first measuring port 25 and a second measuring port 26, because this third fluid channel section is equipped with a fluid throttle 38. The function of the fluid throttle 38 is to generate clearly distinguishable measured values ​​for the first measuring port 25 and the second measuring port 26 during fluid flow through the fluid channel 15. For this purpose, a second pressure sensor 28 is assigned to the second measuring port 26. This sensor is designed to convert the fluid pressure present at the second measuring port 26 into an electrical sensor signal and is electrically connected to the processing unit 31 via a second sensor line 30.

[0041] The fourth fluid channel section 19 extends between the second measuring port 26 and the output port 14.

[0042] Preferably, the first fluid channel section 16, the second fluid channel section 17 and the fourth fluid channel section 19 each have the same cross-section and the same flow resistance, while the third flow channel section 18 has a considerably greater flow resistance.

[0043] The processing unit 31 is designed to process the first sensor signal of the first pressure sensor 27 and to process the second sensor signal of the second pressure sensor 28 into a flow rate value, which is then further processed into a control signal for the fluid valve 37 in order to ensure flow control for the process gas provided at the output port 14.

[0044] For illustrative purposes only, the flow controller 11 is provided to have a signal line 33, via which a display device, for illustrative purposes only, designed as a light-emitting diode 34, can be controlled. For illustrative purposes only, a malfunction of the flow controller 11 is indicated via the light-emitting diode 34.

[0045] Furthermore, the flow controller 11 has, for example, a communication line 35 which is connected to a communication interface 36 arranged on the housing 12. Data exchange with a higher-level controller (not shown) or with a programming device (also not shown) can take place via the communication interface 36. For example, the flow controller 11 can be parameterized via the communication interface 36. Additionally or alternatively, the flow controller 11 can output an analog or digital error signal via the communication interface 36 if a malfunction of the flow controller 11 should occur.

[0046] Figure 2 schematically shows the functional modules of the processing unit 31. These functional modules, described in more detail below, are in particular program modules of a computer program running in the processing unit 31, which may in particular be designed as a microprocessor or microcontroller (not shown in detail).

[0047] For example, the processing unit 31 is provided to include the following functional modules: fluid flow controller 41, pressure controller 42, flow computer 43, and pressure monitoring 44. Furthermore, the processing unit 31 includes an electronic memory 45 and an electrical output stage 46.

[0048] The fluid flow controller 41 is a control algorithm that reads a flow setpoint from the electronic memory 45 and compares this flow setpoint with an actual flow value provided by the flow computer 43. The task of the fluid flow controller 41 is to calculate a control signal from the difference between the flow setpoint and the actual flow value. This control signal is amplified in the final stage 46 and then supplied to the fluid valve 37 to minimize the determined difference between the flow setpoint and the actual flow value. The flow rate required by the fluid flow controller 41 is calculated by the flow computer 43 on the basis of the first sensor signal of the first pressure sensor 27, which is provided via the first sensor line 29, and on the basis of the second sensor signal of the second pressure sensor 28, which is provided via the second sensor line 30.

[0049] The pressure regulator 42 has the task of limiting the pressure at the output port 14 if it exceeds a predefined maximum value. For this purpose, the pressure regulator 42 receives the second sensor signal from the second pressure sensor 28 via the second sensor line 30.

[0050] The task of the pressure monitoring device 44 is to monitor at least one pressure for exceedance of a predetermined threshold value. It can be provided that the pressure monitoring device uses only the first sensor signal from the first pressure sensor 27, which is supplied via the first sensor line 29, which, in Figure 2, extends from the flow meter 43 to the pressure monitoring device 44. Alternatively, it can be provided that the pressure monitoring device 44 uses only the second sensor signal from the second pressure sensor 28, which is supplied via the second sensor line 30, which, in Figure 2, extends from the flow meter 43 to the pressure monitoring device 44.Preferably, the pressure monitoring system 44 monitors both the first sensor signal of the first pressure sensor 27 for exceeding a first predefined threshold and the second sensor signal of the second pressure sensor 28 for exceeding a second predefined threshold. In principle, the pressure monitoring system 44 is configured to output an error message, also referred to as an error signal, if at least one predefined threshold is exceeded by the respective sensor signal. This error signal then leads, for example, to the activation of the LED 34 and / or to a response from a higher-level control system (not shown) connected to the communication interface 36.

[0051] Beyond providing the error message, the pressure monitoring 44 can also be configured to influence the actual flow value stored in the electronic memory 45 and, by reducing the actual flow value, which is then subsequently read from the memory 45 by the fluid flow controller 41, to reduce the flow through the flow controller 11 in order to ensure that the flow computer 43 can operate with correct sensor signals, which may be compromised if, for example, a constriction has occurred in the output line 4.

Claims

Claims 1. Flow regulator (11) for providing a predefinable fluid flow, comprising a housing (12) in which a fluid channel (15) extends from an inlet port (13) to an outlet port (14), the fluid channel (15) having a valve seat (23) and a throttle section (18), and a valve element (22) which is movably received in the housing (12) between a closed position for the valve seat (23) and an open position for the valve seat (23), wherein a valve actuator (21) is arranged in the housing (12) which is configured to initiate a movement on the valve element (22), and a first pressure sensor (27) which is connected to a first measuring port (25) arranged between the inlet port (13) and the throttle section (18), and a second pressure sensor (28) which is connected to a second measuring port (28) arranged between the throttle section (18) and the outlet port (14). Measuring port (26) is connected,wherein the first pressure sensor (27) and the second pressure sensor (28) are electrically connected to a processing unit (31) which determines an actual flow rate in the fluid channel (15) from first sensor signals of the first pressure sensor (27) and from second sensor signals of the second pressure sensor (28) and which includes a fluid flow controller (41) configured to provide a control signal to the valve actuator (21) for controlling the actual flow rate to a setpoint flow rate, wherein the processing unit (31) is configured for an output, an error message is generated if the first sensor signal exceeds a predetermined first threshold and / or if the second sensor signal exceeds a predetermined second threshold.

2. Flow controller (11) according to claim 1, characterized in that the processing device (31) is configured to gradually reduce the flow setpoint when the predetermined first threshold is exceeded by the first sensor signal and / or when the predetermined second threshold is exceeded by the second sensor signal, until an actual flow value is established by influencing the valve actuator (21) at which the first sensor signal is below the predetermined first threshold and / or at which the second sensor signal is below the predetermined second threshold.

3. Flow regulator (11) according to claim 1 or 2, characterized in that the processing device (31) additionally comprises a fluid pressure regulator (42) in addition to the fluid flow regulator (41), which is configured to limit a first pressure value determined from the first sensor signal to a first maximum pressure value and / or to limit a second pressure value determined from the second sensor signal to a second maximum pressure value.

4. Flow regulator (11) according to claim 1, 2 or 3, characterized in that the valve seat (23) is arranged between the inlet port (13) and the throttle section (18).

5. Flow regulator (11) according to claim 1, 2, 3 or 4, characterized in that the first measuring port (25) is located between- see the valve seat (23) and the throttle section (18).

6. Flow regulator (11) according to one of the preceding claims, characterized in that the valve element (22) and the valve seat (23) together with the valve actuator (21) form a fluid valve (37) from the group: direct-acting poppet valve, direct-acting spool valve, fluidically piloted poppet valve, fluidically piloted spool valve .

7. Method for controlling a flow rate in a fluid channel of a flow controller (11) comprising the steps of: determining a first fluid pressure at a first measuring port (25) of a fluid-flowing fluid channel (15), wherein the first measuring port (25) is arranged between an inlet port (13) of the fluid channel (15) and a throttle section (18) formed in the fluid channel (15); determining a second fluid pressure at a second measuring port (26), which is arranged between the throttle section (18) and an outlet port (14) of the fluid channel (15); calculating an actual flow rate value present in the fluid channel (15) from the first fluid pressure and the second fluid pressure in a flow computer (43) of a processing unit (31); and providing a control signal from the processing unit (31) to a valve actuator (21), which influences a position of a valve element (22) depending on the control signal.which is assigned to a valve seat (23) arranged in the fluid channel (15), wherein the control signal is calculated by a fluid flow controller (41) formed in the processing unit (31), which minimizes a flow deviation between the actual flow value and a target flow value, and wherein the processing unit (31) provides an error message if the, first fluid pressure exceeds a predetermined first threshold and / or if the second fluid pressure exceeds a predetermined second threshold.

8. Method according to claim 7, characterized in that the processing device (31) performs a stepwise reduction of the flow setpoint until, by influencing the valve actuator (21) and the resulting change in position of the valve element (22), an actual flow value is established at which the first sensor signal is below the predetermined first threshold and / or at which the second sensor signal is below the predetermined second threshold.

9. Method according to claim 7 or 8, characterized in that a fluid pressure regulator (42) of the processing device (31) monitors the first fluid pressure and changes the control signal provided by the fluid flow regulator (41) if the first fluid pressure exceeds a predetermined first threshold value and / or that the fluid pressure regulator (42) of the processing device (31) monitors the second fluid pressure and changes the control signal provided by the fluid flow regulator (41) if the second fluid pressure exceeds a predetermined second threshold value.

10. Computer program product comprising a computer program, wherein the computer program comprises software means designed to execute the method according to any one of claims 7 to 9, when the computer program is executed by a microprocessor or microcontroller.

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