Shut-off valve

Abstract

Shut-off valve with a housing (3), a shut-off element (7) arranged within the housing (3), and a drive shaft (6) connected to the shut-off element (7) for moving the shut-off element (7) between a closed position and an open position, characterized in that a device (22) for detecting the rotation and direction of rotation of the drive shaft (6) is arranged on the drive shaft (6), wherein the device (22) for detecting the rotation and direction of rotation of the drive shaft (6) comprises a signal transmitter (24) arranged on the drive shaft (6) and a signal receiver associated with the signal transmitter (24) with two sensors (26) arranged side by side, wherein the device (22) for detecting the rotation and direction of rotation of the drive shaft (6) is connected to an evaluation unit (23) for monitoring the position of the shut-off element (7) on the basis of the signals supplied by the device (22).wherein the evaluation unit (23) has a counter for counting a number of revolutions of the drive shaft (6) on the basis of pulses emitted by the sensors (26) and a computing device for converting a counted number of revolutions into a position of the shut-off element (7), and wherein the evaluation unit (23) has an interface unit via which it can be connected, wired or wirelessly, to an external evaluation unit for the transmission of recorded position data of the shut-off element (7) and / or other stored data.

Description

[0001] The invention relates to a shut-off valve according to the preamble of claim 1.

[0002] These types of shut-off valves are used in fluid lines to limit or interrupt the flow of fluid. They typically consist of a valve body with a through-hole and a shut-off element located inside the valve body, which opens or closes the through-hole. The shut-off element is usually actuated by a drive shaft, which is supported by a bearing bushing in a cover or other housing part of the valve body.

[0003] A shut-off valve of the type mentioned above is known from DE 33 02 979 A1. In this patent, a bearing bushing with an external thread is screwed into an opening with an internal thread on the valve body. The bearing bushing serves to rotatably support an actuator spindle, via which a shut-off wedge located inside the housing can be moved between a lower closed position and an upper open position. A disadvantage of such a shut-off valve is that, in its installed position, it is not possible to tell from the outside whether the shut-off element is in an open or closed position.

[0004] WO 2014 / 079 470 A1 discloses an angle measuring device for detecting the rotational position of a rotatable shut-off element of a shut-off valve for a channel through which a fluid flows, wherein the shut-off element is connected to a rotary actuator via a shaft. A number of permanent magnets are arranged on the shaft, and a magnetic field sensor is associated with the shut-off valve to detect magnetic field vectors or components of magnetic field vectors extending radially to the shaft.

[0005] EP 1 024 267 A2 discloses an actuating device for a throttle valve unit, in which a throttle valve held by a throttle valve shaft is adjustably arranged in a housing unit, which has at least a Hall effect rotary angle sensor unit arranged on the throttle valve shaft, consisting of a stationary unit and a movable unit which is to be moved relative to the stationary unit, a drive unit and a transmission which is arranged between the movable unit and the drive unit, wherein the housing unit at least partially surrounds the stationary and the movable unit.

[0006] DE 10 2010 018 024 A1 relates to a shut-off valve comprising a housing, a valve seat arranged in the housing, and a butterfly valve actuating the valve seat, which is rotatably mounted in the housing by means of a drive shaft, wherein a sealing device is formed in the area of ​​the valve seat. To precisely determine the closing point of the butterfly valve and thus the closed position of the shut-off valve, a sensor device is provided, which consists of a displacement sensor that can be actuated by means of an actuating device arranged on the drive shaft of the shut-off valve.

[0007] WO 91 / 19 168 A1 discloses a method and a system for the non-contact detection of a moving element of a valve part, wherein the moving element is provided with a magnetic field source. A magnetic sensor is arranged near the valve part to provide a signal that depends on the orientation of the magnetic flux generated by the magnetic field source. The signal from the magnetic sensor is then processed to provide an indication of the position or orientation of the moving element.

[0008] CN 2 891 435 Y relates to a device for detecting the direction of rotation of a motor. The device comprises a circular turntable mounted on the output shaft of the motor, a magnetic block mounted on the circular edge of the turntable, a first and a second Hall sensor mounted on a bracket and arranged counterclockwise on the side of the turntable, a detection circuit, and a two-input interface circuit, wherein the angle between the connecting lines of the Hall sensors and the center of the turntable is alpha. The Hall sensors emit a first and second signal, respectively, when they pass the magnetic block.When the motor rotates, the detection circuit can determine the direction of rotation of the motor based on the time difference between the first and second signals, compare the detected motor direction with the preset direction of the motor, and output an alarm signal and a shutdown signal if the direction of rotation deviates from the preset direction.

[0009] DE 101 09 185 A1 relates to an actuator with a housing in which a drive motor, a reduction gear, and a remotely controlled clutch for interrupting the power flow between the drive motor and an actuator are arranged. To achieve high efficiency and to always provide position feedback, the remotely controlled clutch is arranged between the drive motor and a position sensor, and the signals received from the position sensor are stored in a buffer memory.

[0010] The object of the invention is to create a shut-off valve of the type mentioned above in which the position of the shut-off element can be detected and monitored.

[0011] This problem is solved by a shut-off valve having the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

[0012] In the shut-off valve according to the invention, a device for detecting the rotation and direction of rotation of the drive shaft is arranged on the drive shaft. This allows the position of the shut-off element to be detected and monitored even in shut-off valves without an electrical actuator.

[0013] The device for detecting the rotation and direction of rotation of the drive shaft comprises a signal transmitter mounted on the drive shaft and a signal receiver with two adjacent sensors. For simple and contactless detection, the signal transmitter can be at least one permanent magnet located in a transverse bore of the drive shaft. The two sensors of the signal receiver, which are magnetic field sensors in the case of a permanent magnet as the signal transmitter, can be arranged in a holder that is mounted on a bearing bushing used to support the drive shaft. This allows shut-off valves to be easily retrofitted with a device for detecting the position of the shut-off element.

[0014] Instead of using magnetic field-sensitive sensors, such as Hall sensors, magnetoresistive sensors, and reed switches, the rotation of the drive shaft can also be detected using inductive proximity sensors or optical sensors. In this case, the drive shaft has a suitable shape or an appropriate optical reflection pattern.

[0015] In an advantageous embodiment, the bracket can be attached to the bearing bushing by a type of clip connection with a retaining lug that engages in a receiving groove in the bearing bushing. The bracket can also be provided with a locking element, e.g., a threaded pin, to prevent rotation on the bearing bushing.

[0016] The device for detecting the rotation and direction of rotation of the drive shaft is connected to an evaluation unit. The evaluation unit may be equipped with a display device. The rotational position of the drive shaft is detected by the evaluation unit in a simple manner by counting pulses emitted by the sensors when the drive shaft rotates, with two sensors being provided to determine the direction of rotation and, based on this, to establish the counting direction.

[0017] Preferably, the evaluation unit includes a memory for recording the acquired position data of the shut-off element. Furthermore, the evaluation unit has an interface for wired or wireless communication with an external evaluation unit.

[0018] Further features and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the drawing. The drawing shows: Fig. 1: A shut-off valve designed as a gate valve in a perspective view; Fig. 2: a longitudinal section through the in Fig. 1 shut-off valve shown; Fig. 3: a longitudinal section through a hood with a bearing for a drive shaft of the in Fig. 1 shown shut-off valve; Fig. 4: a cross-section along line AA of Fig. 3 and Fig. 5: a shut-off valve with an extension.

[0019] In Fig. Figure 1 shows a shut-off valve designed here as a gate valve, which includes a housing 3 provided with connecting flanges 1 and a through-opening 2 and a hood 5 attached to the housing 3 by means of screws 4 for the bearing of a drive shaft 6 designed here as a drive spindle.

[0020] As from Fig. As can be seen from Figure 2, a locking element 7, designed here as a locking wedge, is movably guided within the housing 3 between a lower closed position and a raised open position. The movement of the locking element 7 between the positions shown in Figure 2 is controlled by the mechanism described in Figure 3. Fig. The lower closed position and a raised open position, as shown in Figure 2, are achieved by the drive shaft 6, which is designed as a drive spindle. The upper section of the drive shaft 6 is rotatably mounted in the housing 5 via a bearing bushing 8 and is axially secured. The lower section of the drive shaft 6 has an external thread 9. The shut-off element 7 includes, in a manner known per se, a spindle nut (not shown) which interacts with the external thread 9 of the drive shaft 6 such that the shut-off element 7 can be moved between the lower closed position and an upper open position by rotating the drive shaft 6. For slidable guidance within the housing 3, the shut-off element 7 has two guide projections 11 on opposite sides, which are fitted with plastic sliding shoes 10.The barrier element 7, designed here as a wedge, contains in a manner known per se a base body made of metal, which is surrounded by a covering made of rubber or another suitable plastic.

[0021] In Fig. Figure 3 shows an enlarged view of the housing 5 with the bearing bushing 8 for the rotatable mounting of the drive shaft 6, which serves to adjust the shut-off element 7. This illustration shows that the drive shaft 6 has a lower threaded shank 12 with the external thread 9, an upper cylindrical section 13 with an annular collar 14, and a square end 15 projecting outwards from the housing 5 for attaching a wrench, handwheel, or other actuating element. The housing 5 has a through-opening 16 with an internal thread 17 and a lower annular shoulder 18. The bearing bushing 8, which has a corresponding external thread 19, is screwed into the internal thread 17. The annular collar 14 of the drive shaft 6 is clamped between the annular shoulder 18 of the housing 5 and a lower end face of the bearing bushing 8 by means of upper and lower disc-shaped sliding elements 20 and 21, respectively.This ensures that the drive shaft 6 is rotatably supported and axially secured within the housing 5. The axial play of the drive shaft 6 can be adjusted by further screwing the bearing bushing 8 in or out.

[0022] From the Fig. 3 and Fig. Figure 4 also shows that the shut-off valve has a device 22 for detecting the rotation and direction of rotation of the drive shaft 6 and an evaluation unit 23 for monitoring the position of the shut-off element 7 based on the signals supplied by the device 22. In the illustrated embodiment, the device 22 for detecting the rotation and direction of rotation of the drive shaft 6 includes a signal transmitter 24 arranged on the drive shaft 6, which in the illustrated embodiment is designed as a permanent magnet. The signal transmitter 24, designed as a permanent magnet, is inserted into a transverse bore 25 in the upper cylindrical section 13 of the drive shaft 6.

[0023] The device 22 for detecting the direction of rotation and number of revolutions of the drive shaft 6 also includes a stationary signal receiver associated with the signal transmitter 24, which comprises two adjacent sensors 26. The sensors 26 are arranged in a holder 27 mounted on the bearing bushing 8 and are connected to the evaluation unit 23 via a signal line 28. Magnetic field sensors, such as Hall sensors or magnetoresistive sensors, are used as sensors 26. The sensors 26 function as incremental encoders, i.e., they each deliver a pulse-shaped signal when they are passed by the pole face of the permanent magnet on the circumference of the drive shaft 6.

[0024] The transverse bore 25 could also be continuous, so that the second pole of the permanent magnet would also extend to the circumferential surface of the drive shaft 6. In this case, twice the number of pulses would occur at the sensors 26 per revolution of the drive shaft 6. Alternatively, several permanent magnets could be arranged in several radial bores to increase the number of pulses supplied by the sensors 26 per revolution of the drive shaft 6 and thus the resolution of the sensor system.

[0025] Reed switches can also be used as magnetic field sensors, whereby the field of one or more of the permanent magnets would have to run in the longitudinal direction of the reed contacts, which could be achieved by arranging a rod-shaped permanent magnet in a longitudinal groove on the circumference of the drive shaft 6 and arranging the two reed switches parallel to this permanent magnet.

[0026] In principle, other types of non-contact sensors, such as inductive proximity sensors, can also be used. In this case, the drive shaft 6 could be provided with one or more radial projections and / or recesses at the level of the sensors 26, which would trigger a pulsed change in the sensor signal as it passes the sensors 26. Optical sensors, particularly in the form of reflective optical sensors, are also suitable. In this case, the circumference of the drive shaft 6 could have one or more sectors with differing optical reflectances at the level of the sensors 26, which would each cause a pulsed measurement signal at the sensors 26 as they pass.

[0027] The evaluation unit 23 processes the signals from the sensors 26 by counting the pulses emitted by the sensors 26. The direction of rotation of the drive shaft 6, and thus also the axial direction of movement of the shut-off element 7, can be determined from the phase relationship, i.e., the temporal sequence of the pulses emitted by the two sensors 26. Depending on the direction of rotation of the drive shaft 6, the counter of the evaluation unit 23 counts either up or down when pulses occur. A counting step occurs when both sensors 26 emit a pulse together.

[0028] The counter of the evaluation unit 23 must be calibrated once. This can be done simply by resetting the counter to zero at one end of the travel path with the position of the shut-off element 7 known. The shut-off element 7 is then moved to the other end of the travel path, causing the counter to count upwards. The final reading of the counter then represents the other end position of the shut-off element 7. From this, any position between the two end positions can be easily determined by the evaluation unit 23 from the counter reading using a proportional calculation. An actuating element is provided on the evaluation unit 23 for resetting the counter.

[0029] The holder 27, designed in the form of a ring-shaped cover cap, is attached in the manner of a clip connection to a part 29 of the bearing bushing 8 that projects upwards relative to the hood 5 and has according to Fig. 3 on its inner side a flexible retaining rib 30 for engagement in an annular receiving groove 31 on the upper side of the bearing bushing 8.

[0030] In Fig. Figure 4 shows that the part 29 of the bearing bushing 8, which projects upwards from the hood 5, has a hexagonal shape. The bracket 27, which is mounted on this part 29, contains a locking element 32, designed here as a threaded pin, which is arranged in a transverse bore 33 with an internal thread. The bracket 27 can be secured against rotation on the bearing bushing 8 by means of this locking element 32.

[0031] The evaluation unit 23, in the illustrated embodiment, includes a display device 34, for example, a light indicator, for showing the position of the shut-off element 7. In a simpler version, the display device 34 can contain light elements to indicate the open or closed position of the shut-off element 7. The display device 34 can, for example, be an LED display with one or more light-emitting diodes. This allows, for example, the display of not only the open and closed positions of the shut-off element 7, but also intermediate positions. Further information about the operation of the shut-off valve can also be recorded and stored in the evaluation unit and, if required, read out or transmitted via a suitable interface to a computer or another external evaluation unit. Data transmission could be via cable or wirelessly, for example, via a USB or Bluetooth interface.

[0032] In addition to the current position of the shut-off element 7, previous positions stored in the evaluation unit's memory, along with the times at which these positions were set, can also be transmitted – i.e., a chronological log of the shut-off valve's usage. The evaluation unit 23 is equipped with a real-time clock to generate such a chronological log. Furthermore, identification data of the shut-off valve, such as type and serial number, stored in the evaluation unit 23 can also be transmitted.

[0033] At the in Fig. In the embodiment shown in Figure 1, the evaluation unit 23 is arranged on the hood 5. However, it can also be mounted on a housing that is Fig.The extension 35 shown in Figure 5 is arranged as follows. Such an extension 35 contains a tube 36 that can be placed on the hood 5, in which an actuating rod 37, which can be coupled to the square end 15, is arranged. The evaluation unit 23 can be arranged at the upper end of the extension 35 and connected via a longer signal line 28 to the device 22 for detecting the direction of rotation and number of revolutions of the drive shaft 6.

[0034] The invention is not limited to the embodiment shown in the drawing and described in detail above. It is applicable not only to gate valves, but also to ring piston valves, hydrants, or other shut-off valves with a shut-off element movable within a housing between a closed position and an open position.

Claims

[1] Shut-off valve comprising a housing (3), a shut-off element (7) arranged inside the housing (3) and a drive shaft (6) connected to the shut-off element (7) for moving the shut-off element (7) between a closed position and an open position, characterized by, that a device (22) for detecting the rotation and direction of rotation of the drive shaft (6) is arranged on the drive shaft (6), wherein the device (22) for detecting the rotation and direction of rotation of the drive shaft (6) comprises a signal transmitter (24) arranged on the drive shaft (6) and a signal receiver associated with the signal transmitter (24) with two sensors (26) arranged side by side, wherein the device (22) for detecting the rotation and direction of rotation of the drive shaft (6) is connected to an evaluation unit (23) for monitoring the position of the shut-off element (7) on the basis of the signals supplied by the device (22), wherein the evaluation unit (23) has a counter for counting a number of rotations of the drive shaft (6) on the basis of pulses emitted by the sensors (26) and a computing device for converting a counted number of rotations into a position of the shut-off element (7),and wherein the evaluation unit (23) has an interface unit via which it can be connected, either wired or wirelessly, to an external evaluation unit for the transmission of recorded position data of the shut-off element (7) and / or other stored data. [2] Shut-off valve according to claim 1, characterized by , that the signal transmitter (24) is at least a permanent magnet arranged in a transverse bore (25) of the drive shaft (6) and that the sensors (26) are magnetic field sensors. [3] Shut-off valve according to claim 2, characterized by , that the sensors (26) are Hall sensors or magnetoresistive sensors. [4] Shut-off valve according to claim 1, characterized by , that the signal generator is at least a permanent magnet arranged in a longitudinal groove of the drive shaft (6), and that the sensors (26) are reed switches. [5] Shut-off valve according to claim 1, characterized by, that the signal transmitter is at least a radial projection and / or recess in the drive shaft (6), and that the sensors (26) are inductive proximity sensors. [6] Shut-off valve according to claim 1, characterized by , that the signal transmitter is at least a circumferential section of the drive shaft (6) with an optical reflectance that differs from the rest of the circumferential surface of the drive shaft, and that the sensors (26) are optical reflection sensors. [7] Shut-off valve according to any one of claims 1 to 6, characterized by , that the two sensors (26) of the signal receiver are arranged in a holder (27) which can be placed on a bearing bushing (8) serving to support the drive shaft (6). [8] Shut-off valve according to claim 7, characterized by , that the holder (27) is attached to the bearing bushing (8) by a clip connection with a retaining bar (30) which engages in a receiving groove (31) in the bearing bushing (8). [9] Shut-off valve according to claim 7 or 8, characterized by , that the holder (27) contains a locking element (32) for rotationally secured mounting on the bearing bushing (8). [10] Shut-off valve according to any one of claims 1 to 9, characterized by , that the evaluation unit (23) contains a display device (34). [11] Shut-off valve according to claim 10, characterized by that the display device (34) is arranged on a hood (5) or on an extension (35). [12] Shut-off valve according to any one of claims 1 to 11, characterized by , that the evaluation unit (23) has a memory in which position data of the shut-off element (7) and other data can be stored.

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