阅读说明：本技术 带有位置传感器的真空阀 (Vacuum valve with position sensor ) 是由 克里斯托夫·伯姆 艾德里安·埃申莫瑟 凯尔·阿克塞尔·埃尔福德 于 2018-06-28 设计创作，主要内容包括：本发明涉及一种真空阀(1),其具有阀封闭件(4)和驱动单元(7),该驱动单元与所述阀封闭件(4)耦接,该驱动单元具有至少一个移调部件(5)。所述真空阀(1)还具有位置传感器(10、10’)特别是位移或距离传感器,从而可参照所述真空阀(1)的零位置特别是打开位置(O)或关闭位置(G)测量所述阀封闭件(4)的和/或至少一个所述移调部件(5)的位置。(The invention relates to a vacuum valve (1) having a valve closure (4) and a drive unit (7) which is coupled to the valve closure (4) and which has at least one adjustment element (5). The vacuum valve (1) further comprises a position sensor (10, 10'), in particular a displacement or distance sensor, so that the position of the valve closure (4) and/or of at least one adjustment element (5) can be measured with reference to a zero position, in particular an open position (O) or a closed position (G), of the vacuum valve (1).)

1. Vacuum valve (1), in particular a vacuum slide valve, a pendulum valve or a single valve, for regulating a volume or mass flow and/or for gas-tightly interrupting a flow path, having:

a valve seat having a valve opening (2) defining an opening axis (H) and a first sealing surface (3) surrounding the valve opening (2);

a valve closure (4), in particular a valve disk, for controlling a volume or mass flow and/or for interrupting a flow path, having a second sealing surface (6) corresponding to the first sealing surface (3), the variable position of which is determined by the corresponding position and orientation of the valve closure (4);

a drive unit (7) coupled to the valve closure (4) and having at least one movable adjustment element (5), wherein the drive unit (7) is designed to perform an adjustment movement (Bv, Bh, Br) such that the valve closure (4) can be adjusted from an open position (O) into a closed position (G) and vice versa,

in the open position, the valve closure member (4) and the valve seat are present in a contactless manner relative to one another,

in the closed position, in particular by means of a seal (23), there is an axially sealing contact between the first sealing surface (3) and the second sealing surface (6) with reference to the opening axis (H) and thereby hermetically closes the valve opening (2),

it is characterized in that the preparation method is characterized in that,

the vacuum valve (1) further comprises at least one position sensor (10, 10 '), wherein the position sensor (10, 10') is designed and arranged in the vacuum valve (1) such that the position of the valve closure (4) and/or of the at least one adjustment element (5) can be measured, in particular continuously, with reference to a zero position (O, G), in particular the open position (O) or the closed position (G).

2. Vacuum valve (1) according to claim 1, characterized in that the position sensor (10, 10') is constructed and arranged in the vacuum valve (1) such that a time profile of at least a part of the transposition movement (Bv, Bh, Br) can be determined, in particular such that: at least the speed of the transposition movement (Bv, Bh, Br) can be determined for at least one time segment of the transposition movement (Bv, Bh, Br).

3. Vacuum valve (1) according to claim 1 or 2, characterized in that the position sensor (10, 10 ') is configured as a displacement sensor or a distance sensor and/or as an absolute position sensor (10, 10').

4. Vacuum valve (1) according to one of the preceding claims, characterised in that the transposition movement (Bv, Bh, Br) comprises an at least substantially rectilinear transposition movement (Bv, Bh) and the position sensor (10) is constructed and arranged for detecting at least a part of the rectilinear transposition movement (Bv, Bh), in particular wherein the position sensor (10) is a linear encoder.

5. Vacuum valve (1) according to one of the preceding claims, characterized in that the transposition motion (Bv, Bh, Br) comprises an at least substantially rotational transposition motion (Br) and the position sensor (10 ') is constructed and arranged for detecting at least a part of the rotational transposition motion (Br), in particular wherein the position sensor (10') is an angular encoder.

6. Vacuum valve (1) according to any of the preceding claims, characterized in that the position sensor (10, 10')

-is an inductive, optical, magnetic, magnetostrictive, potentiometric and/or capacitive position sensor (10, 10'); and/or

Arranged outside a vacuum region defined by the vacuum valve (1) and separated from the external environment.

7. Vacuum valve (1) according to one of the preceding claims,

the position sensors (10, 10 ') are designed and arranged in the vacuum valve (1) such that position measurements with reference to at least two, in particular substantially mutually perpendicular, adjustment directions can be carried out by means of one of the position sensors (10, 10'); alternatively, the first and second electrodes may be,

the vacuum valve (1) has at least two position sensors (10, 10 ') which are designed and arranged in the vacuum valve (1) in such a way that a position can be measured by means of a first position sensor (10, 10 ') with reference to a first displacement direction and a position can be measured by means of a second position sensor (10, 10 ') with reference to a second displacement direction, in particular wherein the two displacement directions are substantially perpendicular to one another; and/or

The valve seat is formed by a part of the vacuum valve which is connected to the vacuum valve (1) in terms of design, in particular wherein the valve seat is formed on a housing (24) of the vacuum valve (1) or is provided by a process chamber, in particular a chamber housing.

8. The vacuum valve (1) as claimed in one of the preceding claims, characterized in that the vacuum valve (1) has a processing unit (11) which is designed such that a detected position sensor measurement signal can be processed by means of the processing unit (11) and status information of the vacuum valve (1) can be determined by means of the detected measurement signal.

9. Vacuum valve (1) according to claim 8, characterized in that status information is provided about the mechanical and/or structural integrity of the valve closure (4) and/or of the adjustment component (5), in particular wherein the status information is determined by means of an actual-given-comparison for the detected measurement signal.

10. Vacuum valve (1) according to claim 8 or 9, characterized in that an output signal is provided in respect of an evaluation of a process controlled by the vacuum valve (1) based on a comparison of the status information with a predefined tolerance value.

11. Method for controlling a vacuum valve (1), in particular a vacuum slide valve, a pendulum valve or a single valve, wherein the vacuum valve (1) is designed for controlling a volume or mass flow and/or for interrupting a flow path in a gas-tight manner, and the vacuum valve (1) has:

a valve seat having a valve opening (2) defining an opening axis (H) and a first sealing surface (3) surrounding the valve opening (2);

a valve closure (4), in particular a valve disk, for controlling a volume or mass flow and/or for interrupting a flow path, having a second sealing surface (6) corresponding to the first sealing surface (3), the variable position of which is determined by the respective position and orientation of the valve closure (4);

a drive unit (7) coupled to the valve closure (4) and having at least one movable adjustment element (5), wherein the drive unit (7) is designed to perform an adjustment movement (Bv, Bh, Br) such that the valve closure (4) can be adjusted from an open position (O) into a closed position (G) and vice versa,

in the open position, the valve closure member (4) and the valve seat are present in a contactless manner relative to one another,

in the closed position, in particular by means of a seal (23), there is an axially sealing contact between the first sealing surface (3) and the second sealing surface (6) with reference to the opening axis (H) and thereby hermetically closes the valve opening (2),

it is characterized in that the preparation method is characterized in that,

within the scope of the method, in particular, an absolute position of the valve closure (4) and/or of at least one of the adjustment elements (5) can be measured, in particular continuously, with reference to a zero position (O, G), in particular the open position (O) or the closed position (G).

12. The method according to claim 11, characterized in that, within the scope of the method, on the basis of the position measurement, state information of the vacuum valve (1), in particular with regard to the mechanical and/or structural integrity of the valve closure (4) or of the adjustment element (5), is ascertained, in particular,

the state information is determined by means of an actual given comparison for the detected measurement signals; and/or the presence of a gas in the gas,

-providing an output signal in respect of an evaluation of a process controlled by the vacuum valve (1) based on a comparison of the status information with a predefined tolerance value.

13. A method according to claim 11 or 12, characterized in that in the context of the method, based on the location measurement:

determining a displacement speed of the valve closure (4) and/or of at least one displacement element (5) at least for a part of the displacement movement (Bv, Bh, Br); and/or the presence of a gas in the gas,

determining the duration of the transposition movement (Bv, Bh, Br) from the open position (O) to the closed position (G) and/or vice versa.

14. A method according to any one of claims 11 to 13, characterized in that, in the context of the method, based on the location measurement:

detecting an end position, in particular an open position (O) and/or a closed position (G), of the valve closure (4) and/or of at least one of the adjustment elements (5); and/or

Detecting possible mutual collisions of these sealing surfaces (3, 6) during the transposition movement (Bv, Bh, Br); and/or

Detecting possible mutual adhesion of these sealing surfaces (3, 6).

15. A computer program product for carrying out the method according to claim 11, having a program code or a computer data signal embodied by electromagnetic waves, the program code being stored on a machine-readable carrier, in particular on a control and processing unit of a vacuum valve (1) according to claim 1.

Technical Field

The invention relates to a vacuum valve with at least one position sensor and a method for controlling a position measurement of a vacuum valve.

Background

In general, vacuum valves for regulating a volume or mass flow and/or for substantially gastight closing of a flow path through an opening formed in a valve housing are known in various embodiments of the prior art, which vacuum valves are used in particular in vacuum chamber systems in the field of IC, semiconductor or substrate manufacturing, which manufacturing has to be carried out in a protected atmosphere as far as possible without impurity particles. Such a vacuum chamber system comprises, in particular, at least one evacuable vacuum chamber which is provided for accommodating a semiconductor device or substrate to be processed or produced and has at least one vacuum chamber opening through which the semiconductor device or other substrate can be introduced into and removed from the vacuum chamber, and at least one vacuum pump for evacuating the vacuum chamber. For example, in a manufacturing apparatus for a semiconductor wafer or a liquid crystal substrate, a high-sensitivity semiconductor or liquid crystal element sequentially passes through a plurality of process vacuum chambers, and in these process vacuum chambers, portions located in the process vacuum chambers are processed by one processing device, respectively. Highly sensitive semiconductor devices or substrates must always be in a protected atmosphere, particularly in a vacuum environment, both during the processing process inside the processing vacuum chamber and during the transfer from chamber to chamber.

For this purpose, on the one hand, peripheral valves for opening and closing the gas supply or discharge are used, and on the other hand, transfer valves for opening and closing transfer ports of vacuum chambers for inserting and removing components are used.

The vacuum valves through which the semiconductor components pass are referred to as vacuum transfer valves, depending on the described field of application and the dimensioning associated therewith, also as rectangular valves, depending on their substantially rectangular opening cross section, also as slide valves, rectangular slide valves or transfer slide valves, depending on their usual mode of operation.

The peripheral valve serves in particular to control or regulate the gas flow between the vacuum chamber and the vacuum pump or the further vacuum chamber. The peripheral valves are located, for example, inside the piping between the process vacuum chamber or transfer chamber and the vacuum pump, atmosphere or another process vacuum chamber. The open cross-section of such valves (also known as pump valves) is typically smaller than that of vacuum transfer valves. Peripheral valves are also referred to as regulating valves, since they serve, depending on the field of application, not only for fully opening and closing an opening, but also for controlling or regulating the flow by continuously regulating the opening cross section between a fully open position and a gastight closed position. A pendulum valve is one possible peripheral valve for controlling or regulating the gas flow.

With a typical pendulum valve, which is known, for example, from U.S. Pat. No. 6,089,537(Olmsted), in a first step a generally circular valve disk is swiveled via a generally likewise circular opening from a position opening the opening, i.e. an open position, into an intermediate position covering the opening. In the case of the slide valve described, for example, in U.S. Pat. No. 6,416,037(Geiser) or U.S. Pat. No. 6,056,266(Blecha), the valve disk is configured like an opening, mostly rectangular, and in this first step moves linearly from a position releasing the opening to an intermediate position covering the opening. In this intermediate position, the valve disk of the pendulum valve or slide valve is spaced apart from the valve seat surrounding the opening. In a second step, the distance between the valve disk and the valve seat is reduced, so that the valve disk and the valve seat are pressed uniformly against one another, so that the valve closure reaches a closed position in which the opening is substantially hermetically closed. The second movement is preferably carried out substantially in a direction perpendicular to the valve seat.

The respective end positions of the adjustment movement, i.e. the open position and the closed position (and the intermediate position if there is an adjustment movement consisting of two partial movements in at least two different adjustment directions), are identified or held in this case by means of mechanical limit switches. For precise closure, narrow tolerance limits are disadvantageously adhered to here.

The sealing can take place, for example, either by means of a sealing ring arranged on the closing side of the valve disk or by means of a sealing ring on the valve seat, which is pressed against the valve seat surrounding the opening, against which the closing side of the valve disk is pressed. Due to the closing process which takes place in two steps, the sealing ring between the valve disk and the valve seat is hardly subjected to shear forces which damage the sealing ring, since the movement of the valve disk in the second step takes place essentially linearly perpendicular to the valve seat.

Different sealing devices are known from the prior art, for example from US 6,629,682B2 (dullli). Suitable materials for the sealing rings and seals in vacuum valves are, for example, fluororubbers, also known as FKM, in particular the fluoroelastomer known under the trade name "Viton", and perfluororubbers, abbreviated to FFKM.

Different drive systems are known from the prior art for realizing a rotary movement of the valve disk parallel to the opening for the wobble valve and a translatory movement for the slide valve and for realizing a substantially translatory movement perpendicular to the opening, for example from US 6,089,537(Olmsted) for the wobble valve and from US 6,416,037(Geiser) for the slide valve.

The pressing of the valve disk against the valve seat must be carried out appropriately, both to ensure the required gas tightness over the entire pressure range and to avoid damage to the sealing medium, in particular the sealing ring in the form of an O-ring, as a result of excessive pressure loads. To ensure this, known valves provide for a controlled regulation of the pressure of the valve disks as a function of the pressure difference which arises between the two disk sides. However, in particular in the case of high pressure fluctuations, or in the case of a change from negative to positive pressure or vice versa, a uniform force distribution along the entire circumference of the sealing ring is not always ensured. It is often desirable to disengage the seal ring from the support force generated by the pressure applied to the valve. For this purpose, for example, US 6,629,682(Duelli) proposes a vacuum valve with a sealing medium, which consists of a sealing ring and an adjacent support ring, so that the sealing ring has substantially no support force.

In order to achieve the required tightness, if necessary, both for overpressure and underpressure, in addition to or instead of the second displacement step, some known pendulum valves or slide valves provide a valve ring which can be displaced perpendicularly to the valve disk and around an opening, which ring is pressed against the valve disk in order to close the valve in a gastight manner. Such valves have a valve ring which is actively movable relative to the valve disk, and are known, for example, from DE 1264191B 1, DE 3447008C 2, US 3,145,969 (destination) and DE 7731993U. US 5,577,707(Brida) describes a pendulum valve having a valve housing with an opening and a valve disk which can be swung parallel across the opening and which serves to control the flow through the opening. The valve ring surrounding the opening can be actively moved vertically in the valve disk direction by means of a plurality of springs and compressed air cylinders. One possible improvement of such a pendulum valve is proposed in US 2005/0067603a1(Lucas et al).

Since the above-described valves are used in particular for the production of highly sensitive semiconductor components in vacuum chambers, a corresponding sealing effect must be reliably ensured even for such process chambers. For this reason, the state of the sealing material or the state of the sealing surface that is in contact with the sealing material when pressed is particularly important. During the operating life of a vacuum valve, the sealing material or sealing surface is often subject to wear.

Furthermore, the mechanical moving parts of the drive system or of the valve are prone to failure, for example due to wear or ageing phenomena, or due to external disturbing influences such as mechanical shocks or the like, which can thus lead to a loss of the sealing effect, or often to a loss of the function or reliability of the vacuum valve. To date, there is no way in the prior art to timely or pre-detect such errors.

Therefore, in order to constantly maintain the quality of the valve or the seal at a sufficiently high level, valve maintenance is frequently performed at certain time intervals in such a manner that parts of the valve, such as the seal, the drive element or the valve as a whole, are replaced or renewed. Such a maintenance cycle is usually calculated here by means of the number of opening and closing cycles expected over a certain period of time. Therefore, maintenance is usually carried out with great care in order to largely avoid leaks or other faults in advance.

Such maintenance requirements are not limited solely to sealing material or valve disks, but extend, for example, also to valve seats which form a part of the vacuum valve corresponding to the valve disk. The sealing surface structure on the valve seat, such as a groove embedded in the valve seat, is also subject to mechanical stress. Therefore, the seal may also be damaged by a change in the groove structure caused by the operation of the valve. For this purpose, corresponding maintenance intervals are usually also specified.

A disadvantage of this valve maintenance is its precaution. Maintenance-related parts are often upgraded or replaced before their normal or actual service life has expired, which means a drastic increase in costs. In addition, each such maintenance step typically requires a certain amount of downtime to perform the production process, and requires an increased technical and financial investment. In summary, this means that the time interval for the downtime is shorter than necessary, and the downtime is more frequent than necessary at all.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved vacuum valve which allows an optimized operation.

It is a further object of the present invention to provide an improved vacuum valve which allows for optimal valve maintenance, thereby allowing for improved, i.e. reduced, possible process downtime.

It is another object of the present invention to provide an improved vacuum valve which extends the life of the various valve components.

It is a further object of the present invention to provide an improved vacuum valve which imposes less stringent tolerance requirements on individual components or manufacturing.

These objects are achieved by realizing the features of the characterizing part of the independent claims. Features which further improve the invention in alternative or advantageous ways can be found in the dependent claims.

The basic idea of the invention is to equip the vacuum valve with a position sensor, and to design the valve and the position sensor in such a way that a preferably continuous determination or monitoring of the position of at least one mechanically moving part of the valve is thereby possible.

The subject matter of the invention is therefore a vacuum valve, preferably a vacuum slide valve, a pendulum valve or a single valve, for regulating a volume or mass flow and/or for gas-tightly interrupting a flow path, having a valve seat with a valve opening defining an opening axis and a first sealing surface surrounding the valve opening. The valve seat can be an integral or structural component of the vacuum valve, in particular embodied as a part of the valve housing. Alternatively, the valve seat can be formed by an opening of a process chamber, for example a vacuum chamber, which forms a vacuum valve in the sense of the invention in cooperation with a valve closure which is movable relative to the valve seat.

Furthermore, the vacuum valve comprises a valve closure member, in particular a valve disk, for controlling the volume or mass flow and/or for interrupting the flow path, which valve closure member has a second sealing surface corresponding to the first sealing surface, the variable position of which second sealing surface being determined by the respective position and orientation of the valve closure member. In addition, the vacuum valve has a drive unit coupled to the valve closure member, which drive unit has at least one movable displacement element, for example a displacement arm, wherein the drive unit is designed for a displacement movement, so that the valve closure member can be displaced from an open position, in which the valve closure member and the valve seat are present in a relatively contactless manner, into a closed position, in which, in particular by means of a seal, a contact which is axially sealed with respect to the opening axis is present between the first sealing surface and the second sealing surface and thereby seals the valve opening in a gas-tight manner, and vice versa.

In particular, one or both of the two sealing surfaces have a seal made of a sealing material. The sealing material may for example be a polymer-based material (e.g. an elastomer, in particular a fluoroelastomer) which is vulcanized onto the sealing surface or which is present as an O-ring in a groove on the valve closure or valve seat. Therefore, within the scope of the present invention, a sealing surface is preferably considered to be a surface: a seal made of sealing material is present in compression to close the valve opening (closed position).

The drive unit is designed, for example, as an electric motor (stepper motor) or as a combination of several electric motors or as a pneumatic drive. In particular, the drive unit provides for movement of the valve closure in at least two (substantially mutually perpendicular) directions.

According to the invention, the vacuum valve has at least one position sensor, wherein the position sensor is designed and arranged in the vacuum valve such that the position of the valve closure and/or of the at least one adjustment component, in particular of the adjustment arm, can be measured, preferably continuously, with reference to a zero position, in particular an open position or a closed position.

The position sensor is preferably a displacement sensor with a position-specifying element. Alternatively, the sensor is designed as a distance sensor. In the case of multiple sensors, both types may also be used. The position sensor is preferably designed as an absolute position sensor, so that the position can be determined without reaching the zero position, for example by means of a unique position code on a scale, a solid body or a sensor scale.

Preferably, the sensor is constructed and arranged in the vacuum valve, so that a time curve (Verlauf) of at least a part of the transposition movement can be determined. A plurality of positions is thus determined continuously over a certain period of time, for example such that: so that at least the displacement movement or the speed of the displacement element and/or the valve closure member can be determined or derived for at least this time section of the displacement movement. Furthermore, acceleration may also be determined from the position measurements.

Optionally, the transposition motion comprises an at least substantially linear motion and the position sensor is constructed and arranged to detect at least a part or all of the linear motion, wherein the position sensor is preferably a linear encoder.

Alternatively or additionally, the transposition movement comprises an at least substantially rotational movement and the position sensor is constructed and arranged to detect at least a part or all of the rotational movement, wherein the position sensor is preferably an angular encoder.

Optionally, the position sensor is an inductive, optical, magnetic, magnetostrictive, potentiometric and/or capacitive position sensor. As a further alternative, the position sensor is arranged outside a vacuum region defined by the vacuum valve and separated from the external environment. In this case, it is therefore advantageous that the sensor assembly (sensorandnung) can be designed, for example, such that, for example, the sensor itself does not have to enter the vacuum region, so that a comparatively low construction effort can be ensured.

In some embodiments, the position sensor is designed and arranged in the vacuum valve such that a position measurement with reference to at least two, in particular substantially mutually perpendicular, adjustment directions can be carried out by means of the one position sensor, i.e. a single position sensor can determine the position with reference to a plurality of axes or directions. This is done, for example, as follows: the object of the sensor is to be received by the plurality of scales either sequentially, for example first when the adjustment is carried out in the first adjustment direction and then when the adjustment is carried out in the second adjustment direction, or simultaneously, for example by being designed as a 2D position sensor. Alternatively, the vacuum valve has at least two position sensors which are designed and arranged in the vacuum valve such that a position can be measured by means of a first position sensor with reference to a first adjustment direction and a position can be measured by means of a second position sensor with reference to a second adjustment direction, in particular the two adjustment directions being substantially perpendicular to one another.

In one embodiment, the vacuum valve has a monitoring and control unit for controlling the drive unit with a predetermined control value in order to adjust the valve closure between the open position and the closed position, wherein the drive unit, the valve closure and the sensor are designed and cooperate in such a way that the control value is set on the basis of a measurement signal of the sensor, in particular in such a way that the measurement signal continuously corresponds to a predetermined setpoint value.

In this case, the vacuum valve, the sensor assembly and the monitoring and control unit can, for example, optionally be designed such that the position sensor is in unilateral or bilateral communication, for example, for the purpose of providing and transmitting measurement signals via a conventional wired or wireless connection to the monitoring and control unit.

The vacuum valve may also have, for example, a processing unit which is configured, in particular, provided by the monitoring and control unit or the sensor assembly, such that the detected measurement signals can be processed by means of the processing unit and the status information can be generated by means of the detected measurement signals. The detected measurement signals can then be further processed and provided for providing evaluable status information, for example for valve regulation by a monitoring and control unit or as user information.

The status information can, for example, provide information about the mechanical and/or structural integrity of the valve closure and/or the adjustment element, for example, on the basis of an actual-specified comparison of the detected position measurement signal, for example on the basis of a detected and desired position of a reference position (setting) of the drive unit.

Furthermore, an output signal may be provided based on the status information, the output signal indicating the detected position sensor measurement signal in relation to the determined tolerance value. In particular, the process controlled by the vacuum valve can thus be evaluated, for example, to determine whether a desired sealing effect has been achieved or possible damage to the adjustment element or to the sealing surface can be detected, for example. For example, visual or audible signals may then be used to indicate to the user: whether the process is performed within the required tolerances or is expected to be undesirably below or exceeding such tolerances (e.g., based on the cadence speed or final position).

The invention also comprises a method for controlling a vacuum valve, in particular a vacuum slide valve, a pendulum valve or a single valve, wherein the vacuum valve is designed for regulating a volume or mass flow and/or for interrupting a flow path in a gas-tight manner. In this case, the vacuum valve to be controlled: having a valve seat with a valve opening defining an opening axis and a first sealing surface surrounding the valve opening, a valve closure member, in particular a valve disk, for regulating a volume or mass flow and/or for interrupting a flow path, the valve closure member having a second sealing surface corresponding to the first sealing surface, the variable position of which is determined by the respective position and orientation of the valve closure member; a drive unit coupled to the valve closure part and having at least one movable displacement element, wherein the drive unit is designed for a displacement movement such that the valve closure part can be displaced from an open position, in which the valve closure part and the valve seat are in a contactless manner relative to one another, into a closed position, in which, in particular, a sealing element makes axially sealing contact between the first sealing surface and the second sealing surface with reference to the opening axis, and thereby closes the valve opening in a gas-tight manner, and vice versa.

According to the invention, in the context of the method, the, in particular absolute, position of the valve closure and/or of the at least one adjustment element relative to the zero position, in particular the open position or the closed position, is measured, in particular continuously.

In a refinement of the method, it is within the scope of the method that status information of the vacuum valve, in particular with respect to the mechanical and/or structural integrity of the valve closure or the adjusting element, is determined on the basis of the position measurement, wherein preferably the status information is determined by means of an actual-given-comparison to the detected measurement signal and/or an output signal relating to the evaluation of the process controlled by the vacuum valve is provided on the basis of a comparison of the status information with a predetermined tolerance value.

Optionally, within the scope of the method, the speed of the valve closure and/or of the at least one adjusting element is determined at least for a part of the adjusting movement and/or the duration of the adjusting movement from the open position into the closed position and/or vice versa is determined on the basis of the position measurement. This information can be output to the user in the form of a graph for evaluation and/or automatically evaluated.

As a further alternative, in the context of the method, the end position, in particular the open position and/or the closed position, of the valve closure and/or of the at least one adjustment element is detected on the basis of the position measurement, and/or possible mutual impacts of the sealing surfaces and/or possible mutual adhesion of the sealing surfaces in the range of adjustment movement is detected.

The invention also relates to a computer program product for carrying out the method according to the invention, having a program code or a computer data signal embodied by electromagnetic waves, which is stored on a machine-readable carrier, in particular on a control and processing unit of the vacuum valve according to the invention.

The invention therefore advantageously provides a vacuum valve which permits continuous or continuous measurement of the position of the valve closure and/or the transposition component, so that transposition movements or transposition sequences can be monitored or checked and, if necessary, evaluated. Furthermore, the position measurement allows an automatic and continuous status verification of the vacuum valve or its individual components, such as the drive unit, the seal or the adjustment component, wherein status information about the moving component can be determined or derived not only directly, but also indirectly about the stationary component. Faults or abnormal situations indicating future errors can be discovered as early or important here and/or unnecessary maintenance can be avoided on the basis of ascertained failures. In this case, the check can advantageously be carried out in the normal process sequences, so that these process sequences do not have to be interrupted.

Drawings

The vacuum valve according to the invention will be described in more detail below purely by way of example with reference to the exemplary embodiment shown schematically in the drawing. Like parts are marked with the same reference numerals in the figures. The embodiments are generally not shown to be dimensionally precise, nor should they be construed as limiting.

Specifically, the method comprises the following steps:

fig. 1a, b show a possible first embodiment of a vacuum valve according to the invention as a single valve;

fig. 2 shows a possible second embodiment of the vacuum valve according to the invention as a single valve;

3a-c show a possible further embodiment of a vacuum valve according to the invention as a transfer valve;

FIGS. 4a, b show a schematic view of a vacuum valve as a pendulum valve according to another embodiment of the present invention;

FIGS. 5a, b show schematic views of a vacuum valve as a transfer valve according to another embodiment of the present invention;

fig. 6a, b show a schematic view of a vacuum valve as a transfer valve according to another embodiment of the invention.

Detailed Description

Fig. 1a, b schematically show a first embodiment of a vacuum valve 1 according to the invention. In this example, the valve 1 is designed as a so-called single valve and is shown in cross section in an open position O (fig. 1a) and a closed position G (fig. 1 b).

The valve 1 for the gas-tight closure of a flow path by a linear movement has a valve housing 24 with an opening 2 for the flow path, wherein the opening 2 has a geometric opening axis H along the flow path. The opening 2 connects the first gas region L, which is located to the left in the figure of the valve 1 or the partition wall (not shown), with the second gas region R to the right thereof. Such a partition wall is formed by, for example, a wall of the vacuum chamber.

The closing element 4 is linearly displaceable along a geometric adjustment axis V extending transversely to the opening axis H in the closing direction in the closing element plane 22 from an open position O, in which the opening 2 is released, into a closed position G, in which it is linearly displaced through the opening 2, and conversely is displaceable in the opening direction by means of the drive unit 7 with the aid of a movable adjusting element 5 (in the present case a adjustment arm).

For example, the curved first sealing surface 3 surrounds the opening 2 of the valve housing 24 along a first section 21a in the first plane 20a and a second section 21b in the second plane 20 b. The first plane 20a and the second plane 20b are spaced apart from each other, extend parallel to each other and to the closure member plane 22. The first section 21a and the opposite second section 21b are mutually transverse to the axis of adjustment V and have a geometric offset in the direction of the opening axis H. Between the two opposite sections 21a and 21b, an opening 2 is arranged in the region extending along the adjustment axis V.

The closure member 4 has a second sealing surface 6 corresponding to the first sealing surface 3, which extends along sections corresponding to the first and second sections 21a, 21 b.

The transfer valve requires a relatively complex drive, for example, a single valve, i.e., a vacuum valve which can be closed by a single linear movement, for example, has the advantage of a relatively simple closing mechanism, in comparison to a transfer valve which can be closed by two movements. Since the closure element can also be constructed in one piece, it is subject to large acceleration forces, so that the valve can also be used for rapid and emergency closing. The closing and sealing can be performed by a single linear movement, so that a very rapid closing and opening of the valve 1 can be achieved.

In particular, the advantage of a single valve is, for example, that the seal 3, 6, due to its course, is not subjected to transverse loads in the transverse direction with respect to the longitudinal extent of the seal 3, 6 when closed. On the other hand, the seals 3, 6, due to their transverse extent with respect to the opening axis H, are unable to absorb the forces which occur along the opening axis H on the closure element 4, which forces act on the closure element 4, in particular in the case of large pressure differences, which requires a durable construction of the closure element 4, its drive and its support.

According to the invention, the vacuum valve 1 shown in fig. 1a and 1b comprises a displacement sensor 10, which in this example has a component (target) 8 for a given position and a sensor surface 9 (scale) for its detection. The displacement sensor 10 is designed, for example, as a (contactless) inductive displacement sensor, such as a differential transformer with a movable core, a pulse-induced linear-position sensor, a PLCD displacement sensor (permanent magnet contactless linear displacement sensor), a photoelectric displacement sensor, a potentiometric displacement sensor, a magnetostrictive displacement sensor, a capacitive displacement sensor or a magnetic displacement sensor. Depending on the sensor 10, the scale 9 is active and the component 8 in the given position is inactive, or vice versa, i.e. a (electrical or electronic) measurement signal or evaluation signal is generated or extracted either by the scale 9 or by the component 8.

In this case, the target 8 is fixed on or in the adjustment element 4, so that the target is moved along the adjustment axis V by means of the adjustment element. The sensor surface 9 extends at least over the entire adjustment path in the adjustment direction V, so that the position of the target 8 and thus of the adjustment element 4 can be measured over the entire possible linear movement of the adjustment element 4. In this case, this position is determined relative to an initial position or zero position, which is preferably either the open position O or the closed position G. The displacement sensor 10 is preferably an absolute encoder. Instead, an incremental displacement sensor is employed.

By means of the position sensor 10, the actual position of the adjustment element 4 can thus advantageously be determined. The position measurement can be restricted to determining one or several positions, preferably the end positions (i.e. the open position O and/or the closed position G), for example in the sense of detecting the end position. However, a continuous or continuous position determination is preferably carried out, so that the position of the adjustment element 4 is continuously known, in particular its time curve.

By means of the sensor assembly according to the invention, it is thus possible, for example, to check the closing capacity of the valve during the course of a treatment, to adjust the pressure of the pressure correspondingly, and if necessary to predict a failure of the seal. In particular, the pressing situation can be adjusted individually, for example with an electrical drive unit 7. With the pneumatic drive 7, the sensor assembly can be used to check at least whether the valve is closed.

The knowledge of the movement time profile is optionally utilized to determine therefrom the speed of the linear movement of the closing member 4. This speed can advantageously be taken into account for an improved end position determination, thereby making errors in the vacuum valve less critical. In this way, the exact duration of the closing or opening process can also be determined, so that, for example, optimization or error detection can be carried out. In general, the analysis of the time/path curve, for example by an external data processing device to which the position sensor 10 or the vacuum valve 1 is connected, allows the state of the valve 1 to be inferred. Irregularities or changes in the course of the operating cycle can thus be detected, so that, for example, the state of the moving component or of the sealing surfaces 3, 6 is deduced. If the two sealing surfaces 3, 6 abut against one another in the closed position G, for example, this can be detected by means of the movement profile, since the position of the adjustment member 4 remains constant for a certain time due to the holding force, although it is driven by the drive unit 7 via the adjustment member 5, followed by a rapid opening movement and a brief rebound.

Fig. 2 shows an alternative to the embodiment according to fig. 1a, 1 b. In the present example, the vacuum valve 1 has a position sensor 10, which is designed as a distance sensor. The distance sensor 10 is, for example, an optoelectronic distance sensor or an ultrasonic sensor, and emits a corresponding measuring signal 13, for example, a laser beam, by means of a transmitter toward the tuning body 4 or the vertical axis V, so that the signal 13 reaches the tuning body 4 (in the present case its rear side), is reflected at least in part therefrom, and is received again by the detector of the sensor 10. By determining the signal propagation time (pulse propagation time method) and/or phase difference measurement, phase or frequency propagation time method and/or according to the fizeau principle, the distance between the sensor 10 and the adjustment element 4 and thus the position of the adjustment element 4 is determined. As a further alternative, the position determination is performed by triangulation.

In order to improve the distance or position measurement, the vacuum valve 1 has a reflector 14, which is arranged on the adjustment element and is designed to reflect the measurement signal 13 toward the sensor 10, thereby improving the signal level of the received measurement signal 13.

Instead of the arrangement shown, the sensor 10 is arranged on the moving part, i.e. here the closure 4, and sends the measuring radiation 13 to the rest position of the valve 1 (i.e. an arrangement opposite to that shown).

Fig. 3a to 3c show a further embodiment of a vacuum valve 1 according to the invention in different closed positions, which is designed as a transfer valve in the present case.

The transfer valve shown is one particular form of spool valve. The vacuum valve has a rectangular, plate-like closing part 4 (e.g. a valve disk) with a sealing surface 6 for the gas-tight closing of the opening 2. The opening 2 has a cross-section corresponding to the closing member 4 and is formed in the wall 12. The opening 2 is surrounded by a valve seat which itself likewise provides a sealing surface 3 corresponding to a sealing surface 6 of the closure part 4. The sealing surface 6 of the closure member 4 surrounds the closure member 4 and has a sealing material (seal). In the closed position, the sealing surfaces 6, 3 are pressed against one another and the sealing material is pressed in.

The opening 2 connects the first gas region L located on the left side of the wall 12 with the second gas region R located on the right side of the wall 12. The wall 12 is formed, for example, by a wall of a vacuum chamber. The vacuum valve 1 is then formed by the co-operation of the chamber wall 12 with the closing member 4.

The closing element 4 is arranged on a transposition arm 5, here for example in the form of a rod, and extends along a geometric transposition axis V. The adjustment arm 5 is mechanically coupled to a drive unit 7, by means of which the closures 4 can be adjusted in the first gas area L on the left side of the wall 12 by adjustment of the adjustment arm 5 from the open position O (fig. 3a) via the intermediate position Z (fig. 3b) to the closed position G (fig. 3c) by means of the drive unit 7.

In the open position O, the closing member 4 is located outside the projected area of the opening 2 and completely opens the opening, as shown in fig. 3 a.

By adjusting the adjustment arm 5 parallel to the first "vertical" adjustment axis V and parallel to the wall 12 in the axial direction, the closure part 4 can be adjusted from the open position O to the intermediate position Z by means of the drive unit 7.

In this intermediate position Z (fig. 3b), the sealing surface 6 of the closure part 4 covers the opening 2 and is in a spaced-apart, opposed position with respect to the sealing surface 3 of the valve seat surrounding the opening 2.

The closure element 4 can be displaced from the intermediate position Z into the closed position G (fig. 3c) by displacing the displacement arm 5 in the direction of a second "horizontal" displacement axis H (transverse to the first displacement axis V), i.e. for example perpendicular to the wall 12 and the valve seat.

In the closed position G, the closing member 4 hermetically closes the opening 2 and hermetically separates the first gas area L from the second gas area R.

The opening and closing of the vacuum valve is thus effected by the drive unit 7 by an L-shaped movement in two mutually perpendicular directions H, V of the closure part 4 and the adjustment arm 5. Thus, the delivery valve shown is also called an L-valve.

The transfer valve 1 as shown is typically provided for sealing of the process chamber (vacuum chamber) and for loading and unloading of the chamber. In this use case, frequent switching between the open position O and the closed position G is common. The sealing surfaces 6, 3 and other parts of the moving mechanical components, such as the adjustment part 5 or the drive unit 7, can thus be exposed to severe wear phenomena.

In order to determine such wear phenomena in a timely manner, in particular, according to the invention, the vacuum valve 1 has a position sensor 10, which is in this case designed as a two-axis displacement sensor. Unlike the embodiment according to the example of fig. 1a, b, the position is determined in both adjustment directions V, H by means of the target 8 arranged on the adjustment part 5. For this purpose, the vacuum valve 1 has a first "vertical" scale 9v for the position determination of a "vertical" movement between the open position O and the intermediate position Z, and a second "horizontal" scale 9h for the position determination of a "horizontal" movement between the intermediate position Z and the closed position G. By means of the target 8 arranged on the adjustment member 5 and by means of the first scale 9v, thus in a sequential order, according to a sequential movement order: the open position O — the intermediate position Z — the closed position G (or vice versa), the position of the adjustment element 5 in the first "vertical" adjustment direction V is measured, and the position in the second "horizontal" adjustment direction H is measured by means of the target 8 and the second scale 9H.

In this case, the valve 1 or the position sensor 10 also has a control and/or evaluation unit 11, by means of which position measurement and/or recording or evaluation of position data is controlled, so that, for example, an external computer can be omitted (to a large extent) and, for example, a pure valve-internal monitoring or condition monitoring of the valve 1 can be carried out.

Instead of the two linear scales 9V, 9H arranged one behind the other as shown, a single 2D sensor surface (not shown) is used, which is scanned optically, for example, so that the position of the adjustment element 5 can be determined simultaneously in two axes or directions V and H.

As a further alternative, instead of a position determination for two displacement directions V, H or two displacement movements by means of a single position sensor 10, the valve 1 has a position sensor 10 for each displacement direction V, H or displacement movement, respectively, i.e. comprises two position sensors 10.

Fig. 4a and 4b schematically show another possible embodiment of a valve in the form of a pendulum valve 1 according to the invention. The valve 1 for substantially gas-tight interruption of a flow path has a valve housing with an opening 2. The opening 2 here has, for example, a circular cross section. The opening 2 is surrounded by a valve seat. The valve seat is formed by a (first) sealing surface 3 having the shape of a circular ring extending in the axial direction towards the valve disk 4 and transversely to the opening axis H, which sealing surface is formed in the valve housing. The valve disk 4 is pivotable about a rotational axis R and is displaceable substantially parallel to the opening axis H. In the closed position G (fig. 4b) of the valve disk 4 (valve closed), the opening 2 is closed in a gas-tight manner by means of the valve disk 4 having the second sealing surface 6. The open position O of the valve disk 4 is shown in fig. 4 a.

The valve disk 4 is connected to a drive unit 7 by an arm 5 arranged laterally on the disk and extending perpendicularly to the opening axis H. The arm 5 is located outside the opening cross section of the geometric projection of the opening 2 along the opening axis H in the closed position G of the valve disk 4.

The drive 7 is designed by using an electric motor and corresponding transmission, so that the valve disk 4, as is usual with pendulum valves, can be swiveled between the open position O and the intermediate position in the form of a swiveling movement Br about a swiveling axis R by a transverse movement x of the drive 7 transverse to the opening axis H and essentially parallel along the cross section of the opening 2 and perpendicular to the opening axis H, and can be moved linearly by a longitudinal movement Bv of the drive 7 parallel to the opening axis 5. In the open position O, the valve disk 4 is located in a stagnation section arranged beside the opening 2, releasing the opening 2 and the flow path. In the intermediate position, the valve disk 4 is spaced above the opening 2 and covers the open cross section of the opening 2. In the closed position, the opening 2 is closed gas-tightly and the flow path is interrupted in such a way that there is a gas-tight contact between the valve closure 4 (valve disk) and the sealing surface 3 of the valve seat.

In order to be able to open and close the valve 1 automatically and in a controlled manner, the valve 1 for example defines an electronic control and regulation unit (not shown) which is designed and connected to the drive 7, so that the valve disk 4 can be adjusted accordingly in order to close the process chamber in a gas-tight manner or to regulate the internal pressure of the chamber.

In the present exemplary embodiment, the drive element 7 is designed as an electric motor, wherein the transmission element is switchable such that the drive of the drive element 78 causes either a transverse movement Br or a longitudinal movement Bv. The driving member and the transmission member are electronically controlled by the control portion. In particular, such transmission elements with slotted switching are known from the prior art. It is also possible to use a plurality of drives to generate the rotational movement Br and the linear movement Bv, the control unit taking over the control of these drives.

With the pendulum valve 1, the flow rate can be controlled or regulated precisely, not only by the valve disk 4 being adjusted in a pendulum manner by a transverse movement Br between the open position O and the intermediate position, but in particular by the valve disk 4 being adjusted linearly along the opening axis H or R between the intermediate position and the closed position by a longitudinal movement Bv. The described pendulum valve 1 can be used for precise control tasks.

Both the valve disk 4 and the valve seat have a sealing surface, a first and a second sealing surface 3, 6, respectively. The first sealing surface 3 also has a seal 23. The seal 23 may be vulcanized to the valve seat, for example as a polymer by vulcanization. Alternatively, the seal 23 can be embodied, for example, as an O-ring in a groove of the valve seat. It is also possible to glue the sealing material to the valve seat and thereby cure the sealing member 23. In an alternative embodiment, the seal 23 can be arranged on the valve disk 4, in particular on the second sealing surface 6. Combinations of these designs are also contemplated. Such a seal 23 is of course not limited to the valve 1 described in this text, but can also be applied to the other valve embodiments described.

The valve disk 4 is variably adjusted, for example, by means of control variables and output control signals. As input signal, information is obtained, for example, about the current pressure state in the process chamber connected to the valve 1. In addition, the regulator can be provided with a further input variable, for example the mass flowing into the volume. By means of these parameters and by means of a predetermined set pressure that is to be set or reached for the volume, the valve 1 is then set in a controlled manner over the time of the setting cycle, so that the mass flowing out of the volume can be set by means of the valve 1 over this time. For this purpose, a vacuum pump is arranged downstream of the valve 1, i.e. the valve 1 is arranged between the process chamber and the pump. The desired pressure curve can thus be set.

By adjusting the valve closure 4, the corresponding opening cross section of the valve opening 2 is adjusted, and thus the amount of gas which can possibly be withdrawn from the process chamber per unit time. For this purpose, the valve closure element 4 can have a different shape than a circular shape, in order in particular to achieve a flow of the medium that is as laminar as possible.

For adjusting the opening cross section, the valve disk 4 can be displaced by the control and regulation unit from the open position O into the intermediate position by means of a transverse movement Br of the drive element 7 and from the intermediate position into the closed position by means of a longitudinal movement Bv of the drive element 7. In order to open the flow path completely, the valve disk 4 can be displaced by control from the closed position G into an intermediate position by means of a longitudinal movement Bv of the drive 7 and from there from the intermediate position into the open position O by means of a rotational movement Br of the drive 7.

The valve disk 4 must be pressed against the valve seat in order to ensure the required gas tightness over the entire pressure range and to avoid damage to the valve 1 or, more precisely, to the sealing surfaces 3, 6 or the seal 23 due to too great a pressure load. To ensure this, known valves specify: the contact pressure of the valve disk 4 is controlled as a function of the pressure difference generated between the two sides of the valve disk.

According to the invention, the valve 1 has two position sensors 10 and 10 ', which in the present case are configured as a linear encoder 10 and an angular encoder 10'.

The linear position sensor 10 has a scale 9 which extends on the arm 5 in the linear direction of movement Bv and is thus movable in the advancing direction Bv relative to a stationary part of the valve 1, i.e. for example relative to the valve housing or the drive unit 7. The corresponding relative position is detected by the linear encoder by means of a read head 8 which scans a scale 9 and has a position code for this purpose. The scale 9 and/or the reading head are designed at least partially "wide" in this case, so that the linear position can also be measured in different rotational positions of the arm 5. For example, the scale 9 thus extends around the arm 5 to such an extent that a portion thereof is opposite the detector 8, whether in the open position O or in the closed position G, and the scale 9 does not swing out of the "field of view" of the detector 8.

The position code is preferably an absolute position code. Alternatively, the position code is an incremental code. For the absolute position sensors 10, 10', any relative position of the read head 8 with respect to the scale 9 can be assigned directly a position (with respect to the predefined zero position) in that the scale 9 has an absolute position code from a single code word along the entire measuring section, which can be assigned to exactly one position by the control and evaluation unit. Whereas for position sensors 10, 10' that incrementally determine position, the scanning signal is not singular, but is repeated multiple times over the entire measuring range. In the control and analysis unit of the encoder "which distance is equal to the increment" is stored. The distance covered by the relative movement of the scale 9 and readhead 8 can thus be determined, and the relative position determined by counting the increments. In order to locate this relative position absolutely, starting from a defined zero position as an absolute reference point during the relative movement. Such a zero position or zero point is for example defined by a position reference mark on the scale 9 (or on the readhead 8 when the scale 9 is fixed) which is detectable by the readhead 8. The disadvantages of the sensors 10, 10' that incrementally determine the translational position or angle are thus: when the measuring system is restarted, it must start again from the zero position or the reference position each time. In contrast, an absolute linear encoder or an angular encoder produces a single distinguishable scan signal for each relative position of parts that can be translated or rotated relative to each other. In this way, a single linear position or a single angle can be assigned to the respective relative position directly, i.e. without reaching the reference position or the initial position.

The second position sensor 10 ', which is designed as an angular encoder, likewise has a scale 9 ' which is scanned by the read head 8 ' and which carries an absolute or incremental angular coding, so that information can be obtained about the angular position of the arm 5 and thus of the valve disk 4. The scale 9 'extends in this example at least partially around the arm 5 (at least to some extent, thereby covering the circumference of the rotational movement Br), so that it is rotatable with the arm 5 relative to the fixed detector 8' or the entire fixed part of the valve 1.

By means of the first and second position sensors 10, 10', the position of the valve 1, in particular of the moving part of the valve disk 4, and thus in particular the state of the vacuum valve 1, can be advantageously monitored and continuously evaluated with regard to the required reliability of the gas-tight or gas-tight closure.

Instead of the pendulum valve 1 as described, the vacuum valve 1 according to the invention can be realized with another vacuum valve, for example a tilting valve, a slide valve or a so-called butterfly valve. Furthermore, it is also possible to use pendulum valves, the closure of which can be displaced only in one direction.

Fig. 5a and 5b schematically illustrate another possible position sensor assembly in the transfer valve of the present invention, shown in a closed position G (fig. 5a) and an open position O (fig. 5 b). In the illustrated figures, the valve seat 3 is formed on the housing 24 of the vacuum valve 1. It will be apparent to those skilled in the art that the following description is substantially similarly applicable to embodiments in which the valve seat is provided by the process chamber, i.e. the chamber housing.

It goes without saying that the valve mechanism shown here purely exemplarily as a wobble mechanism is not to be understood in a limiting manner, but that the person skilled in the art can use the inventive sensor assembly, for example, in a similar manner for any L-shaped motion drive, for example, an L-shaped motion drive with two mutually perpendicular linear displacement directions of the valve disk.

For the controlled guidance of the adjustment arm 5, the vacuum valve 1 here has, for example, a guide assembly 15, wherein the drive unit 7 and the guide assembly 15 are each in a fixed arrangement with respect to one another, in such a way that, for example, both the drive unit 7 and the guide assembly 15 are each connected in a fixed position to the valve housing 24. The adjusting arm 5 is also mechanically coupled to the valve closure element 4 and to the drive unit 7, wherein the valve closure element 4 is adjustable by displacement of the adjusting arm 5 by means of the drive unit 7 between the open position O and the closed position G substantially parallel to the valve seat, in particular in an L-shaped movement, as illustrated in fig. 3a to 3 c.

According to the invention, the guide assembly now has a position sensor 10. The position sensor 10 is designed in such a way that it can measure both the "vertical" component V and the "horizontal" component H of the movement of the arm 5 or the valve disk 4. For example, the position sensor 10 has a rotary encoder for this purpose, which serves both to determine the pivot position (i.e. the "horizontal" component) of the arm 5 and to determine the linear translation thereof, in that this translation is converted beforehand into a rotational movement. Instead of what is shown, two separate position sensors are used, and/or one or more position sensors are arranged elsewhere in the valve, for example on the driver 7.

On the basis of fig. 5a, 5b, fig. 6a and 6b show another possible embodiment of the vacuum valve 1 according to the invention. In contrast to the embodiment according to fig. 5a, 5b, the position sensor 10 for measuring the position of the valve closure 4 or the adjustment member 5 is designed as a system with an illumination device 16, for example an LED, for illuminating the rear end of the adjustment arm 5 and a camera system 17 for detecting the illumination radiation reflected by the adjustment arm 5. The camera system 17 has, for example, a detector which senses the position, so that the position of the adjustment arm 5 can be inferred from the projection position of the reflected radiation onto the detector. Alternatively, an image is generated, for example, by means of the detected radiation, and the image is analyzed, so that the position can be determined therefrom. Camera-based position determination is known in principle from the prior art. It is also known to use optically detectable patterns to improve position determination with respect to an image. Accordingly, as shown, the rear end of the adjustment member 5 has such an optical pattern 18. The "horizontal" position of the adjustment element 5 can be deduced from the position of the pattern 18 in the camera image, and its "vertical" position (distance from the camera) can be deduced from the imaging size of the imaged pattern or parts thereof (compared to stored reference parameters).

It goes without saying that the figures shown only schematically show possible embodiments. The various solutions can likewise be combined with each other and with the methods and devices of the prior art.