Position sensing device for hydraulic or electrohydraulic drives, and drive having position sensing means

Abstract

A device (10) for position detection of the rotational or linear position of a movable part of an actuator, particularly a hydraulic or electro-hydraulic actuator, the device being functionally reliable under extreme environmental conditions such as extremely low temperatures or explosion risks, wherein the movable part (1) performs rotational or linear adjustment relative to a stationary part (2), the device comprising: a switching unit (3) comprising a plurality of switches (31, 32, 33, 34, 35) arranged in a row, wherein the switching unit (3) is located at the stationary part (2); and an actuating element for directly or indirectly actuating the switches (31-35) of the switching unit (3) according to the relative position of the movable part (1). The control module is equipped with an operating element (4) having multiple switch triggers (41, 42, 43, 44, 45) corresponding to the number of switches (31-35) of the switch unit (3), and the switch triggers (41-45) are respectively assigned to the switches (31-35) by a successive arrangement and / or arrangement between the movable part (1) and the stationary part (2), such that a fixed and definite combination of switch positions of the switches (31-35) is given at any relative position between the movable part (1) and the stationary part (2), and the control module is equipped with an evaluation unit that stores the codes of different switch positions of the switches (31-35) relative to the movable part (1) of the driver.

Description

Technical Field

[0001] This invention relates to a device for detecting the rotational or linear position of a movable part of an actuator, particularly a hydraulic or electro-hydraulic actuator, which remains functionally reliable even under extreme environmental conditions, such as extremely low temperatures and explosion hazards. The position detection device according to the invention particularly relates to hydraulic actuators with movable parts that perform rotational or linear adjustment movements beyond a predefined adjustment stroke, wherein the rotational or linear position of the movable parts is detected as accurately as possible using the device according to the invention. Such a device for position detection can also be referred to as a sensor or position transmitter for portions of actuators with movable parts, such as rotating shafts or drive rods. Background Technology

[0002] In the prior art, potentiometers or other sensors that continuously detect rotational position are known to be used, for example, to detect the rotational position of such actuators or accessories. Such potentiometers continuously detect the corresponding position of the movable part of the actuator and output the result for further processing. In many hydraulic actuators, such as those used for operating valves, ball valves, or the like, potentiometers that detect the complete adjustment movement are commonly used. Potentiometers are therefore accurate, but often prone to failure. On the other hand, it is also known that the corresponding end position of the adjustment stroke of such hydraulic actuators is detected only using corresponding limit switches, thus lacking information about the relative position of the adjustment stroke in the intermediate positions between the initial and end positions. This leads to drawbacks and limitations in the control and adjustment of such hydraulically driven accessories.

[0003] Furthermore, there are application areas where electrical potentiometers are no longer sufficient to detect the position of movable parts of the actuator, or frequently fail, leading to highly inaccurate control and adjustment of the actuator. For example, in extremely low temperatures as low as -55°C in polar regions, hydraulic actuators used to operate valves, tables, or ball valves may still function normally, but often become insufficiently accurate in adjustment or control due to a lack of information about the relative positions of movable actuator components such as shafts or adjusting rods. Consequently, the relative positions of movable parts of rotating shafts or linearly adjustable units used for rotary motion are often no longer accurately determined. At extreme temperatures, the precise positions of movable actuator parts also vary due to changes in hydraulic oil viscosity or environmental conditions. In other extremely harsh environments, such as high temperatures, explosive hazards, or similar conditions, or combinations thereof, traditional purely electrical position sensors, such as potentiometers, often no longer function properly. This can lead to malfunctions and even the inability to detect positions. On the other hand, extremely inaccurate descriptions may occur when detecting the rotational position or precise location of the adjustable and movable parts of the actuator, resulting in the indirect damage of incorrectly set accessories such as valves or ball valves. Summary of the Invention

[0004] In this context, the objective of the present invention is to provide a device for detecting the rotational or linear position of a movable component of a hydraulic or electro-hydraulic actuator, and a actuator with a position detection device that enables safe detection and sufficiently accurate position determination of the movable component of the actuator in any operating position even under extreme environmental conditions, such as extremely low temperatures down to -55°C. The device according to the invention should also reproduce the actual part and position beyond the adjustment stroke as accurately as possible with minimal technical effort and a relatively compact construction.

[0005] This task is solved by a device having the features of claim 1 and a driver having the features of claim 17. Advantageous and extended designs of the invention are the subject of the dependent claims.

[0006] According to the present invention, a device is proposed for position detection of the rotational or linear position of a movable part of an actuator, particularly a hydraulic or electro-hydraulic actuator, which is functionally reliable even under extreme environmental conditions such as extremely low temperatures and explosion hazards. In this device, the movable part performs rotational or linear adjustment relative to a stationary part. The device includes: a switching unit comprising a plurality of switches arranged side-by-side in a row, wherein the switching unit is located at the stationary part; and an actuating element for directly or indirectly manipulating the switches of the switching unit according to the relative position of the movable part. The device is characterized in that the actuating element has a plurality of switch triggers corresponding to the number of switches of the switching unit, and the switch triggers are respectively assigned to the switches by a successive arrangement and / or arrangement between the movable and stationary parts such that a distinct combination of switch positions is given in any relative position between the movable and stationary parts. A control module with an evaluation unit is provided, in which codes of different switch positions relative to the relative position of the movable part of the actuator are stored.

[0007] The device of the present invention therefore uses multiple simple switches of a switching unit, which are effectively connected to switch triggers arranged opposite to the actuating element, so as to determine the position as accurately as possible, even in the middle position beyond the adjustment stroke of the driver. The present invention thus provides such a driver with quasi-continuous or fault-resistant position detection. The switch triggers are arranged such that they can safely switch the different switches assigned to the switching unit according to a predetermined circuit diagram when the driver is adjusted. The switch triggers are hereby specified, for example, with fixed means, contours, or shapes, so that the different switches are respectively associated with each other in a well-defined combination of switch positions at any point on the movable part of the driver. The well-defined assignment of the combination of switch positions to the (actual) relative positions of the movable parts of the driver is stored in the code according to the invention in the control module, so that the corresponding actual position of the driver can be detected very accurately based on different switch positions or combinations of switch positions without the need for continuous electrical sensors, such as potentiometers. The device according to the invention enables the detection of multiple different positions of a drive in a structurally simple and robust manner through an actuating element connected to a movable component, wherein the actuating element switches on and off corresponding switches depending on the position via a plurality of corresponding switch triggers.

[0008] By using different switching positions, the actual location and position at multiple individual discrete points of the adjustment stroke can be determined based on the code stored in the control module, and with high functional reliability. This invention thus allows for quasi-continuous determination of the relative position of the adjustable movable part of the actuator, without requiring truly coherent continuous measurements via electrical means using potentiometers or other such sensors. Furthermore, even under extreme conditions, such as on ships or similar vessels in polar regions at extremely low temperatures, such as -55°C, it is always functionally reliable and simple to use a row of switches with associated switch triggers at the actuation element, which cooperate with the movable part of the hydraulically driven actuator via a coupled actuator. The solution according to the invention can also provide a fault-resistant device for improved position detection in a structurally very simple and relatively compact form. The switching unit and actuation element can be implemented very closely side-by-side in a fairly small size. Therefore, the device can be easily incorporated into such actuators and accessories.

[0009] The allocation according to the invention between the switch position of the switching unit and the relative position of the actuator can be either a linear, continuous allocation, or an allocation that changes beyond the adjustment stroke. For example, the switch trigger of the actuating element can be configured such that position points that are not so close or so far apart can be detected beyond the adjustment stroke of the hydraulic actuator. For example, actuating elements with such switch triggers can be configured to have a closer detection sequence at critical points in the adjustment of the actuator. This variation of the invention, which can be implemented, for example in an advantageous embodiment, can result in, for example, the switch trigger or actuating element being coupled to a movable component via a non-constant transmission mechanism. The transmission mechanism can be replaced, for example, by a gear transmission mechanism with a constant pitch circle measuring device, due to a transmission ratio that varies across the pitch circle diameter, for example, due to a rotational axis with an eccentric arrangement of the pitch circle of the transmission mechanism element. Alternatively, different types of coupling transmission mechanisms can be used, in which the resolution of the detection adjustment stroke in the selected area is increased or decreased. With this advantageous design of the invention, it is not necessary to further change the switch trigger of the actuating element in terms of the relative switch arrangement. Different ranges of precision can be achieved in detecting the adjustment stroke of the drive by using the shape or arrangement of the control element itself.

[0010] According to an advantageous design of the invention, the switch of the switching unit is a simple switch with switching function, in the form of a reversing switch or a multiple-switch. The switch of the switching unit according to the invention is therefore a switch with a simple structural design and is thus extremely robust and durable and not easily affected by any interference. Each switch in the switch can, for example, be implemented as a simple reversing switch with a unique on / off switching position. Different feasible solutions for such switches arise, such as toggle switches, pressure switches, or other forms of switches, which can be mechanically operated, either directly or indirectly, by contactless switch triggers according to the adjustment of the driver. According to the invention, a simple switch with multiple switching functions, having multiple switching points in one switch, can also be used. In this way, the device can be implemented more compactly in the aforementioned construction form because more switching positions and combinations of switching positions are provided for coded determination of the driver position compared to a reversing switch with only a simple on / off function.

[0011] According to another advantageous design of the invention, the switch is equipped with a switching surface or switching element for adjustment by means of a switch trigger in direct contact. The switch trigger can be formed as a cam of a switch lever, a cam roller, or a cam rail (cam rod), or other forms of component, which cooperate with the switching surface or switching element of the switch to actuate the switch unit, with the switching surface or switching element correspondingly positioned in a corresponding manner. Thus, position can be determined without interference and with functional reliability, even under extreme external conditions.

[0012] According to another alternative embodiment of the invention, the switch is a contactless switch or a non-contact switch. The switch can be configured, for example, as a so-called reed contact, Hall sensor, inductive switch, or capacitive switch. Non-contact operation has advantages in certain applications, namely, that direct contact between the switch trigger and the switch itself is not required. The switch trigger and the actuating element can therefore be arranged at a certain distance from the original switching unit. This has further advantages, as it also avoids mechanical interference caused by dirt, etc.

[0013] According to another advantageous design of the invention, the actuating element is mechanically and directly connected to the movable component due to the adjusting movement of the actuator. This direct mechanical connection between the actuating element and the movable component of the actuator, such as the drive shaft or drive rod of a hydraulic actuator for an accessory, can be accomplished, for example, by corresponding gear connections, transmission mechanisms, splined shafts, or similar mechanical coupling devices known to those skilled in the art. The device can thus detect the corresponding adjustment stroke and the position of the actuator with extreme accuracy. The device can determine the corresponding position, for example, at a fixed adjustment stroke between a starting position and an ending position, at a separately defined intermediate position of the switch by the actuating element with a switch trigger, by detecting a code in the control unit. Alternatively, the device can be used to determine the unrestricted adjustment stroke of the rotating shaft of a hydraulic device, for example, a rotating actuator. This direct mechanical connection according to the invention between the actuating element and the moving component of the actuator allows for extremely accurate detection of the corresponding position using simple devices without the need for fully continuous electrical measurements, such as potentiometers or the like.

[0014] According to another advantageous design of the invention, the actuating element is constructed in the form of a camshaft or cam roller, with several different cams acting as switch triggers for different switches, the cams contacting the switches. Thus, according to the invention, the actuation of the switches is triggered by the specific shape of the cams on the camshaft. The camshaft or cam roller is thus constructed in a very compact manner, for example, with different shapes and different numbers of cams. For example, a single cam can be provided on the cam roller for the first and second switches respectively, and with the complete rotation of the cam roller, the switch is either in the open or closed position. For the third, fourth, or fifth switches, two, three, or even eight cams are formed respectively in a circumference with corresponding multiple transitions according to the single cam shape. According to the invention, such a cam roller can induce a large number of possible position combinations of the switches in a very compact manner. The number of positions for position detection is therefore large. The actuating element is thus very compact and has a very simple construction of a switch trigger in the form of several cams differently shaped and arranged on a camshaft, accompanied by fairly accurate quasi-continuous detection of motion.

[0015] According to another advantageous design of the invention, the switching unit with multiple switches is a unified block containing multiple switches arranged vertically or side-by-side within the block, each switch being installed in a fixed position. This achieves a so-called combined switch tower or switching unit with individual switches arranged directly adjacent to or side-by-side. Therefore, the location and position of the switches are reliably determined. The switching unit can also be easily installed and replaced in case of failure. Similarly, multiple such combined switching units can be arranged as block elements at one and the same movable part of the actuator, thus achieving redundancy in detecting the position of the actuator. This further improves the fault tolerance of position detection. The combination of individual switches in the corresponding switching unit also has the advantages of facilitating installation and disassembly and achieving an extremely compact construction of the sensor device.

[0016] According to another advantageous design of the invention, in the control module of the device, the encoding of different switch positions and combinations of switch positions for the rotational or linear positions of the movable parts of the driver is stored in Gray code. This Gray code allows the allocation of combinations of switch positions to corresponding relative positions of the driver to a relatively simple control mechanism. Gray code enables the conversion of multiple simple binary switch positions of a single switch into response codes for the actual positions of the driver. Gray codes can also be easily stored in the storage element of the control unit of the device according to the invention for corresponding structural designs of the corresponding switches of the driver and the switching unit. Other types of encoding can also be used within the scope of the invention to achieve a precise allocation of different switch positions or combinations of switch positions of the switch in the switching unit by the corresponding adjustment movement of the driver.

[0017] According to another advantageous design of the invention, the encoding of the switch position in the control module reproduces a quasi-continuous mapping of different discrete position points of the predefined adjustment stroke of the actuator. The device thus allows for quasi-continuous detection of the corresponding position across the defined adjustment stroke. The encoding is specified and stored such that the corresponding individual position point at the predetermined position maps the adjustment stroke as well as possible and accurately for the corresponding application. Therefore, a sufficiently reliable and accurate alternative for fully continuous position detection can be provided using the solution according to the invention. The invention is not limited to the simple application areas of such hydraulic actuators and can also be advantageously used in more extreme environmental conditions, such as extremely high temperatures, extremely low temperatures, explosive hazards, and combinations of these extreme conditions. The predefined adjustment stroke according to the invention can, for example, be an adjustment between the starting and ending positions of the actuator or fitting. In valve fittings, this is, for example, the open and closed positions of the valve.

[0018] According to another advantageous design of the invention, the encoding of the switch position in the control module of the device maps to position points that cross a predefined distribution of the adjustment stroke of the actuator at regular intervals. These position points, crossing the adjustment stroke at regular intervals, are therefore set at relatively uniform intervals. Thus, the actual position of the hydraulic actuator can be detected by accurately mapping the adjustment positions that cross the adjustment stroke at regular intervals using the present invention.

[0019] According to another advantageous design of the invention, the encoding of the switch position in the control module reproduces the position of the movable part of the driver as it moves across the adjustment stroke of the driver. By arranging and mapping these changes in the driver's position points, a targeted and advantageous design for controlling and adjusting the driver can be achieved. In specific applications, for example, the position near the endpoint is much more important than the position in the initial region of the adjustment stroke. Therefore, a denser arrangement of the switch's detection points is defined in this region. Thus, the device according to the invention can achieve a level of accuracy better suited to the corresponding application.

[0020] The accuracy of detecting overshoot changes in the adjustment stroke of the device according to the invention can be achieved, for example, by having the actuating element eccentrically arranged in the rotating shaft during rotational adjustment. It is also possible to form the actuating element with different types of switching triggers, which allow for the detection of varying triggering torques at different positions of the adjustment stroke. Alternatively, different allocations of the switching triggers of the actuating element can be used, achieving these further advantages in terms of accuracy of detecting overshoot changes in the position of the hydraulically driven actuator.

[0021] According to another advantageous design of the invention, the control module of the device stores an evaluation switch circuit that infers the position of a movable component relative to a stationary component based on the switch position detected so far. This inference module can also accurately predict the future position of the hydraulic actuator within the control module, without needing to determine the already reached position. This module enables predictive control and regulation of the actuator, reliably preventing incorrect wiring or even damage to the actuator.

[0022] According to another advantageous design of the invention, two or more switching units with multiple corresponding switches are arranged at the movable part or at an element of the device directly mechanically connected to the movable part. The device, in this embodiment, thus has multiple switching units to further improve the detection of the corresponding position of the hydraulic actuator. Redundancy or dual function can also be achieved with additional switching units, thus reliably ensuring the detection even in the event of a switch or switching unit failure. Other technical advantages can also be achieved with such multiple switching units, such as a balance between different switching positions to directly compensate for possible inaccuracies or to increase the number of detection points in different arrangements.

[0023] According to another advantageous embodiment of the invention, the actuating element has a switch trigger for the corresponding switch, based on a non-mechanical triggering technique, particularly fluid technology, or an electrical or magnetic actuation. This indirect, mechanically indirect actuation of the switch by the actuating element offers further advantages in specific application environments: for example, in environments with significant shock, vibration, fire hazards, high heat, or electromagnetic radiation, it enables specific applications of position detection for hydraulic actuators, which are sufficiently safe and can be implemented relatively simply in the structural design without requiring a truly continuous potentiometer or the like. Indirect, non-mechanical triggering techniques may also be required in certain areas where the switch components and the switch trigger are not always in convenient, uninterrupted contact with each other. Therefore, advantageous quasi-continuous position detection according to the invention can also be achieved in such environments.

[0024] According to another advantageous design of the invention, the switch trigger or the switch itself of the actuating element includes a device for reducing friction. This friction-reducing device may, in particular, include rollers, sliding elements, or coatings on the contact surfaces of these elements. The advantage of reduced friction is that it enables long-term, uninterrupted operation of position detection without the need for maintenance. Further advantages of reduced friction are that the switch can be easily triggered. The switch is thus reliably positioned in its corresponding predefined position, which is particularly advantageous in the case of multiple switches.

[0025] According to another advantageous embodiment of the invention, a mechanical connection is provided in the form of a transmission mechanism or a gear or toothed element between a drive element of a movable component and an actuating element present at a stationary component. This direct mechanical connection is safe and reliable when the position is detected and transmitted between the drive component of the hydraulic actuator and the transmission element using the device according to the invention. The actuating element is thus directly connected to the hydraulic actuator and its moving component, thereby ensuring reliable and direct transmission of information about the corresponding current position. Similarly, an alternative indirect mechanical connection via a transmission mechanism, toothed element, or the like is also possible.

[0026] According to the present invention, claim 17, a hydraulic or electro-hydraulic actuator for manipulating fittings, particularly valves, ball valves, or valves, by means of a predefined adjustment stroke between, in particular, an open position and a closed position, accompanied by the relative movement of a movable part of the actuator relative to a stationary part, wherein the actuator is characterized in that it includes a device for position detection of the rotational or linear position of the movable part of the actuator, according to any one of claims 1 to 16.

[0027] According to one related embodiment of the invention, the actuator is a hydraulic actuator for the rotational movement of a rotating accessory such as a valve, ball valve, or valve, wherein the movable part of the actuator is a rotating drive shaft, and wherein the device for detecting position is mounted between the drive shaft of the actuator and the stationary part. Attached Figure Description

[0028] Further features, aspects and advantages of the invention are described in more detail below with reference to various embodiments of the invention, in conjunction with the accompanying drawings and illustrations included in the drawings.

[0029] Figure 1 This is a top view of an embodiment of the device for position detection according to the present invention;

[0030] Figure 2 Is according to Figure 1 A perspective view of an embodiment of the device for position detection according to the present invention;

[0031] Figure 3 This is a cross-sectional view of another embodiment of the device for detecting the rotational position of a hydraulic actuator according to the present invention;

[0032] Figure 3a Is according to Figure 3 A three-dimensional view of the detailed control elements of the position detection device;

[0033] Figures 3b to 3eIs as a basis Figure 3 Different cross-sectional views of the cam roller, an example of the operating element of the position detection device according to the invention, in an embodiment; and

[0034] Figure 4 A table illustrating another embodiment of the position detection device according to the invention is provided to illustrate the encoding of switch position combinations and driver positions stored in the control module in the form of Gray code. Detailed Implementation

[0035] exist Figure 1 and Figure 2 The illustration reproduces a first embodiment of a device 10 for position detection of the rotational position of a hydraulic actuator according to the invention. In this embodiment, device 10 includes a switch unit 3 with five switches 31, 32, 33, 34, and 35, which are combined together in the form of a so-called switch tower or switch unit. The switch unit 3 is mounted on a stationary component 2 of the hydraulic actuator, such as a housing component or flange component. The switch unit 3 is connected to an actuating element 4 for operating the switches 31 to 35, wherein the actuating element 4 is mechanically connected directly or indirectly to a movable component 1 of the hydraulic or electro-hydraulic actuator. Rotational movement of an actuator, such as the drive shaft of a hydraulic actuator, is thus mechanically transmitted to the actuating element 4, for example, in the form of a gear assembly, a gear ring, a splined shaft, or the like. When adjusting the hydraulic actuator, the actuating element 4 is operated in conjunction with the adjustment movement of the actuator.

[0036] In this embodiment, the rotational movement of the movable component 1 (the rotating shaft of the actuator) is directly transmitted to a camshaft 6 or cam roller via a large gear connected to the movable component 1 of the actuator. The large gear engages with a smaller gear on the camshaft 6. In this embodiment, the camshaft 6 has five switch triggers 41, 42, 43, 44, and 45 corresponding to the number of switches 31 to 35. These triggers exist in the form of differently shaped cams on the camshaft 6 at corresponding positions of switches 31-35. In this example, the switch triggers 41-45 are directly mounted opposite to the switches 31-35 of the switching unit 3 and are mechanically and directly connected to this switching unit via a friction-reducing device 5, such as a roller, to switch 31-35. When the actuating element 4, in the form of this camshaft 6, rotates, switches 31-35 are respectively turned on or off, wherein a specific combination of the on / off positions of switches 31-35 is given at each part or position of the hydraulic actuator. In this embodiment, the switches 31-35 of the switching unit are simple reversing switches, i.e., binary switches, and thus they are either in the ON position or in the OFF position.

[0037] In this embodiment of the invention, the actuating element 4, shaped as a camshaft 6, has differently shaped cams serving as switch triggers 41-45. The first two switch triggers 41 and 42 each have a single cam extending beyond the circumference of the actuating element 4 to actuate the first two switches 31 and 32, while the third trigger 43 is a double cam, the fourth switch trigger 44 is a quadruple cam, and the fifth switch trigger 45 has eight cam protrusions extending beyond the circumference. This is also due to... Figure 3 and Figures 3a to 3e Further illustrations show that the differently shaped switch triggers 41-45 in this embodiment of the actuating element 4 for the switching unit 3 are clearly visible. In this embodiment, the switches 31-35 of the switching unit 3 are simple reversing switches, which, through the differently shaped switch triggers 41-45, have fixed and defined switching combinations in any rotational position of the rotating part 1 of the hydraulic actuator. However, multiple switches with more than two switching positions can also be used. The switches are thus combined and mounted at the switching unit 3 such that the switches, in cooperation with the switch triggers 41-45 of the actuating element 4, have defined switching combinations in the corresponding rotational positions of the movable part 1 of the actuator. The switches 31-35 are either on or off with each rotational position, as this embodiment involves simple reversing switches. To reduce friction, rollers 5 are provided at the ends of the switches that contact the actuating element 4 as friction-reducing devices. As explained below, the switch, by being operated in this manner by the actuating element 4, allows the corresponding code to explicitly determine the corresponding rotational position of the hydraulic or electro-hydraulic actuator, the code being stored in the control module (not shown).

[0038] exist Figure 4 The table presents the information regarding... Figures 1 to 3 The illustrated embodiment uses an example of Gray encoding, which is stored in the control module of device 10. Due to the allocation and arrangement of actuating elements, in the form of camshafts 6 or cam rollers with different cam shapes, to five switches 31-35, the switches 31-35 are actuated distinctly and differently in each rotational position of 3.09° in the combination. Due to the five binary switches, a total of 2 control modules are generated for device 10. 5 (i.e., 32) possible signal messages, which quasi-continuously reproduce the corresponding rotational positions of the movable component 1 of the hydraulic actuator across the adjustment stroke. This is according to... Figure 4 The example is reproduced in the Gray code of the table.

[0039] The device 10 according to the invention thus allows for quasi-continuous and fault-resistant position detection of rotating components of hydraulic or electro-hydraulic actuators, such as valves for operating ball valves or the like. These devices can also be used on ships or drilling platforms that must function reliably even under extreme conditions, such as temperatures as low as -55°C in polar regions. Conventional electrical potentiometers used to detect the rotational position of rotating components of such hydraulic actuators are no longer feasible. They may malfunction or provide incorrect sensor values. To overcome this drawback, according to the invention, the rotational position is determined quasi-continuously by a combination of the switching positions of switches 31-35 of the switching unit 3. For this purpose, according to the invention, there is a special actuating element 4 that reproduces different, but clearly defined, combinations of switching positions depending on the rotational or linear position of the movable component 1 of the actuator. Switches 31-35 are simple reversing switches in the illustrated embodiment. This involves blocks or towers in the form of combined switching units 3. The number of switches can also be greater than five. Switches 31-35 can also be replaced by a single on / off position switch with multiple switching positions, such as a triple or double reversing switch. This solution according to the invention allows for a greater number of detection points to be implemented through coding in the control module. In the illustrated embodiment, roller 5 at the end of switches 31-35 reduces friction and ensures safe and reliable operation when operated by switch triggers 41-45 with different cams of the cam roller 6, which is in the form of an actuating element 4. However, roller 5 can also be omitted.

[0040] According to the present invention, instead of the directly mechanically connected switches 31-35, contactless switches, such as reed contacts, Hall sensors, inductive switches, or capacitive switches, can also be provided. Correspondingly, separately formed switch triggers 41-45 are provided for this purpose, but according to the present invention, they are also directly or indirectly connected to the movable part 1 of the actuator, such as a rotating shaft or linear rod for adjusting the fitting. In this form, where there is no direct mechanical connection with the contactless switches, due to special coding, the different positions of the movable parts 1 of the multiple switches 31-35 with the switch unit 3 are determined in the control module, and said allocation can be safely and reliably measured under various extreme environmental conditions.

[0041] The device 10 for position detection according to the invention has the advantage that it can operate safely and reliably even under extreme conditions, such as extremely low or high temperatures, impacts, vibrations, fires, and electromagnetic radiation, without operational interference. Furthermore, it ensures fault-resistant adjustment and control of the hydraulic or electro-hydraulic actuator by detecting position quasi-continuously beyond the adjustment stroke. According to an advantageous variation, at least the electrical or electronic components of the device 10 are specifically protected from environmental conditions such as fire, impacts, and electromagnetic radiation. The electronic components, and particularly the control module for storing codes, can be accessed via a corresponding protected housing, shielding structure, or remote device of the normally hydraulic actuator between the switching positions of switches 31-35 in the switching unit 3 and the adjustment stroke position of the movable part 1 of the actuator. In this way, damage to the device for position detection, which could be caused by the failure of individual electronic or electrical components, is prevented when operating under such extreme environmental conditions. Correspondingly, the control module with the evaluation structure and the switches 31-35 of the switching unit 3 are specifically protected from such extreme external environmental conditions.

[0042] In the embodiment shown in the accompanying drawings, a position detection device 10 according to the invention is illustrated for detecting the rotational position of the drive shaft of a hydraulic actuator, such as a valve adjustment fitting. However, the device 10 according to the invention can also be used to detect the linear position of a linearly movable component of such an actuator. The actuating element 4 is then preferably, to a certain extent, an extended cam roller or camshaft or a corresponding cam rod, which cooperates with the corresponding switch based on the arrangement and allocation of switch triggers 41-45 for the actuating element. Alternatively, other switch triggers may be used. In this embodiment, the precise allocation of the combination of the position to the switching positions of the switches 31-35 of the switching unit 3 is also ensured by codes stored in the control module, so as to determine the precise position detection of the actuator corresponding to the actual current position and location of the drive component.

[0043] replace Figure 4 The Gray code shown can be used in other forms of coding and allocation in the control module between the switching positions of switches 31-35 in the switching unit 3 and the actual location of the movable part 1 of the driver. The allocation and coding must be explicitly guaranteed only in this embodiment such that each position of the movable part 1 of the driver reflects a specific combination of the switching positions of switches 31-35.

[0044] The advantage of this Gray code encoding according to this embodiment of the invention is that only one switch changes its switching position at each switching point. Positional deviations of the switch or its components caused by, for example, tolerances in manufacturing and installation, bearing clearances, thermal expansion, etc., are therefore tolerable and do not affect the measurement results. Other encoding systems (in which at least two switches change their states at switching points) are relatively more susceptible to this. However, other forms of encoding can also be used according to the invention. According to the invention, a previously fixed allocation between the adjustment stroke of the movable part of the hydraulic actuator and the switching position of the switch of the switching unit 3 is not necessarily required. It is also possible that a learning path or learning mode is provided in the evaluation electronics of the control module. Here, the hydraulic actuator with movable part 1 adjusts, for example, from a first final position A to a second final position B, and then accordingly adjusts and re-stores the position of the switch trigger of the switching unit 3 or its actuating element to the corresponding encoding allocation. This avoids purely mechanical and costly setup and calibration of the measurement system. Using this learning capability of the control module, a variant of the present invention can be implemented, which makes it easier to infer locations that have not yet been detected.

[0045] The operation of the switch triggers 41-45 via the actuating element 4 can also be performed in a non-mechanical manner. For example, it is conceivable to perform remote operation of the switches 31-35 or to manipulate the switches using different designs, such as electrical or fluid technology. These particular embodiments of the invention provide further advantages under extreme environmental conditions. However, a direct mechanical connection of the actuating element 4 with switch triggers 41-45 (which directly triggers the switches 31-35 of the switching unit 3) is preferred in many applications.

[0046] The shape and form of the cams serving as the switch triggers 41-45 of the camshaft 6 may differ from those shown in the embodiment. For example, the cams may have rounded protrusions and concave portions of different shapes. Alternatively, the switch triggers 41-45 may be simple protrusions, concave portions, or convex portions that interact with corresponding elements at the switches 31-35 to switch the switching unit 3.

Claims

1. A device (10) for position detection of the rotational or linear position of a movable part of a drive, the device being functionally reliable under extreme environmental conditions, wherein the movable part (1) performs rotational or linear adjustment relative to a stationary part (2), the device comprising: a switching unit (3) comprising a plurality of switches (31, 32, 33, 34, 35) arranged side by side in a row, wherein, The switching unit (3) is arranged at the stationary component (2); and the operating element (4) is used to directly or indirectly manipulate the switches (31-35) of the switching unit (3) according to the relative position of the movable component (1), characterized in that the operating element (4) has a plurality of switch triggers (41, 42, 43, 44, 45) corresponding to the number of switches (31-35) of the switching unit (3), and the switch triggers (41-45) are respectively assigned to the switches (31-35) by a successive arrangement and / or arrangement between the movable component (1) and the stationary component (2), such that a fixed and definite combination of switch positions of the switches (31-35) is given at any relative position between the movable component (1) and the stationary component (2), and the control module is provided with an evaluation unit in which codes of different switch positions of the switches (31-35) relative to the relative position of the movable component (1) of the driver are stored.

2. The device (10) according to claim 1, characterized in that, The switches (31-35) are switches with simple switching functions, which are in the form of reversing switches or multiple switches.

3. The device (10) according to claim 1 or 2, characterized in that, The switch (31-35) is equipped with a switch surface or switch element for direct contact adjustment by means of the switch trigger (41-45).

4. The device (10) according to claim 1 or 2, characterized in that, The switch (31-35) is a switch that can be operated without contact or a non-contact switch.

5. The device (10) according to any one of the preceding claims, characterized in that, The actuating element (4) is mechanically directly connected to the movable component (1) due to the adjustment movement of the drive.

6. The device (10) according to any one of the preceding claims, characterized in that, The actuating element includes several different cams on the camshaft (6) as switch triggers (41-45), the cams being in contact with the switches (31-35).

7. The device (10) according to any one of the preceding claims, characterized in that, The switch unit (3) is a uniform block with multiple switches (31-35) installed in fixed positions, either stacked on top of each other or side by side.

8. The device (10) according to any one of the preceding claims, characterized in that, The switching positions of the switches (31-35) in the control module are encoded in Gray code for the rotational or linear position of the movable part (1) of the driver.

9. The device (10) according to any one of the preceding claims, characterized in that, The encoding of the switch positions of the switches (31-35) in the control module reproduces a quasi-continuous mapping of different discrete position points of the predefined adjustment stroke of the driver.

10. The device (10) according to any one of the preceding claims, characterized in that, The switching positions of the switches (31-35) in the control module are encoded and mapped to position points that cross the predefined adjustment travel distribution of the driver at regular intervals.

11. The device (10) according to any one of the preceding claims, characterized in that, The encoding of the switch position of the switch (31-35) in the control module reproduces the position of the movable part (1) of the driver as the adjustment stroke of the driver changes.

12. The device (10) according to any one of the preceding claims, characterized in that, The control module stores an evaluation switch circuit that can infer the position of the movable component (1) relative to the stationary component (2) based on the switch positions of the switches (31-35) detected so far.

13. The device (10) according to any one of the preceding claims, characterized in that, Two or more switch units (3) with multiple corresponding switches (31-35) are arranged at the movable part (1) or at the element of the device (10) that is directly mechanically connected to the movable part (1).

14. The device (10) according to any one of the preceding claims, characterized in that, The manipulation element (4) has a switch trigger (41-45) based on non-mechanical triggering technology.

15. The device (10) according to any one of the preceding claims, characterized in that, The switch trigger (41-45) of the actuating element (4) or the switch (31-35) includes a device (5) for reducing friction.

16. The device (10) according to any one of the preceding claims, characterized in that, The mechanical connection structure is provided in the form of a transmission mechanism, toothed element or gear between the drive element of the movable part (1) and the operating element (4) present at the stationary part (2).

17. The device (10) according to claim 1, characterized in that, The actuator is a hydraulic or electro-hydraulic actuator.

18. The device (10) according to claim 1, characterized in that, The extreme environmental conditions include extremely low temperatures or the risk of explosion.

19. The device (10) according to claim 14, characterized in that, The non-mechanical triggering technology is fluid-based, electrical, or magnetic manipulation.

20. The device (10) according to claim 15, characterized in that, The device is a roller or a sliding element.

21. A hydraulic or electro-hydraulic actuator for manipulating an accessory by means of relative movement of a movable part (1) of the actuator relative to a stationary part (2) accompanied by a predefined adjustment stroke, characterized in that, The device (10) is provided for position detection of the rotational or linear position of the movable part (1) of the driver according to any one of claims 1 to 20.

22. The driver according to claim 21, wherein, The driver is a hydraulic driver for the rotational movement of a rotating accessory, characterized in that the movable part (1) of the driver is a rotating drive shaft and the device (10) is mounted between the drive shaft of the driver and the stationary part (2).

23. The driver according to claim 21, characterized in that, The predefined adjustment travel is between the open and closed positions.

24. The driver according to claim 21, characterized in that, The accessories are valves, ball valves, or other valves.

25. The driver according to claim 22, characterized in that, The rotating fitting is a valve, ball valve, or other similar device.

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