AU2010305079A1

AU2010305079A1 - Measuring device for detecting rotation signals

Info

Publication number: AU2010305079A1
Application number: AU2010305079A
Authority: AU
Inventors: Ameis Rudiger
Original assignee: Elster Messtechnik GmbH
Current assignee: Honeywell Messtechnik GmbH
Priority date: 2009-10-08
Filing date: 2010-10-01
Publication date: 2012-05-10
Anticipated expiration: 2030-10-01
Also published as: WO2011042136A1; EP2486374A1; DE102009048612A1; BR112012008182A2; BR112012008182B1; ES2617700T3; EP2486374B1; DE102009048612B4; AU2010305079B2

Abstract

The invention relates to a vane water meter comprising a measuring device for detecting rotation signals with a measuring insert lying in the measuring chamber (1) of the device, wherein a vane (40) is rotatably held by a vane shaft (30) in the measuring chamber. The measuring device comprises a rotating signal transmitter (20) lying in the measuring chamber (1), said transmitter interacting with the vane (40) and rotating over at least one inductive sensor (10) during a rotation of the vane (40). The rotating signal transmitter (20) is a metal component (20) which forms a closed conductor loop and which is designed as a closed ring, said component being at a different distance from the at least one inductive sensor (10) during the rotation of the vane (40).

Description

Elster Messtechnik GmbH September 28, 2010 Lampertheim Mp.No. 09/101 WO Measuring device for detecting rotation signals Description The invention relates to a flywheel water meter having a measurement apparatus for detection of rotation signals from a rotating signal transmitter by means of an inductive tap for the rotation signals on the rotating signal transmitter according to the precharacterizing clause of claim 1, and to the use of the apparatus as claimed in claim 13. The apparatus according to the invention is particularly suitable for use in electronic flywheel water meters. DE 10 2006 046 864 Al discloses that, in the case of known electronic water meters, in particular in multi-jet flywheel meters, the consumption is measured by using electronic flywheel sampling to detect the measured value. A measurement body is provided for this purpose in the measurement area of the water meter, which measurement body is stored so as to be rotationally moveable and is caused to rotate by the medium flowing through the measurement area, and the rotary movement of the measurement body, which is in the form of a flywheel, is detected electronically by means of inductive sampling of a signal, referred to in the following text as rotation signal, produced during rotation of the flywheel, and is evaluated by downstream evaluation electronics.

Mp.No. 09/101 WO 2 March 21, 2012 For this purpose, the oscillations below a specific damping threshold, are counted, for example in an ASIC, and are compared with the number of oscillations without damping. The difference determined in this way can be used to derive whether the flywheel is rotating or is stationary. In the case of the device known from EP 1 325 286 Al for contactless measurement of the rotation state of the flywheel of a flywheel water meter, by means of three resonant circuit coils, which produce a variable magnetic field in the area above a sensor surface, for example a rotating non-magnetic, metallic damping platelet composed of copper, aluminum, stainless steel or titanium, and for downstream evaluation electronics, measured values, that is to say the number of revolutions of the flywheel, are detected and evaluated. For this purpose, the copper platelet is fitted to the flywheel of the water meter and, during movement of the flywheel, forms a rotating signal transmitter, which interacts with the coils which act as inductive sensors. For the contactless measurement of the rotary movement of the flywheel as described above, the coils are fitted in the dry area of the water meter on the surface of a preferably circular board in the vicinity of the blade of the flywheel to be sampled, with the coils being connected to a measurement board, for example via their connecting wires. In addition, the coils can be directly soldered in the measurement board. Normally, evaluation electronics are arranged on the measurement board, for measured-value detection. However, these evaluation electronics may also be arranged on a main board, which is then electrically connected to the measurement board. The measurement area of the water meter, also referred to as the wet area, with the flywheel and the measurement insert which accommodates the signal transmitter fitted thereto, is separated from the dry area of the water meter by a component composed of non-magnetic material, preferably plastic, which seals the wet area from the dry area in a liquid-tight manner. In order to achieve adequate measurement accuracy for the determination of the rotation signals from the signal transmitter, the physical distance for separation of the wet area and dry area between the rotating signal transmitter, which is Mp.No. 09/101 WO 3 March 21, 2012 in the form of a damping platelet, and the respective coil bodies is limited to a maximum of 5 mm, which results in particularly stringent requirements for the design configuration of the measurement arrangement. When using low-cost iron-powder coils as inductive sensors, which, in conjunction with the flat copper platelet located on the moving blade of the flywheel, produce only a weak magnetic field, the distance to the copper platelet is about 4mm. A further disadvantage of the measurement apparatuses used until now in water meters for detection of the rotation signals from the flywheel of a water meter results from the fact that fluctuations of the blade have a negative influence on the very sensitive measurement apparatus. One embodiment of the damping platelet composed of aluminum would admittedly lead to an improvement in the damping signal for determination of the rotation speed of the flywheel, but aluminum is unsuitable for use as a material for the signal transmitter in the wet area of the water meter. In order to achieve virtually reaction-free flywheel tapping, the coil bodies must also be arranged at a certain minimum distance from the copper platelet, in each case at the same distance from the center point of the circular board below the copper platelet. Measurement optimization is achieved by difference-signal amplification, by positioning the coils precisely horizontally with respect to the copper platelet which is located on the flywheel. If the coils are soldered on the board obliquely or at an angle, this leads to a deterioration in the damping signal which is required for the rotation-speed measurement, and thus to serious measurement errors in the consumption measurement.

Mp.No. 09/101 WO 4 March 21, 2012 Accordingly, the invention is based on the object of specifying a flywheel water meter having a measurement apparatus for detection of rotation signals from a rotating signal transmitter by means of an inductive tap for the rotation signals on the rotating signal transmitter, which operates more reliably and reduces design-dependent measurement errors, for example as a result of inaccurate positioning of the components of the apparatus. According to the invention, this object is achieved by the features specified in claim 1. Advantageous refinements, or improvements in the measurement apparatus according to the invention and use of the measurement apparatus are specified in further claims and in the description. According to the invention, the measurement apparatus in the flywheel water meter for detection of rotation signals comprises a measurement insert which is arranged in the measurement area of the measurement apparatus and in which a measurement body, for example a flywheel, is held by a flywheel shaft, such that it can rotate. The measurement body is connected to a signal transmitter which is arranged in the measurement area, such that this signal transmitter rotates over at least one inductive sensor during a rotary movement of the measurement body. Preferably, the inductive sensor is arranged in a separate built-in part which projects into the measurement area of the measurement apparatus according to the invention. The signal transmitter is in the form of a metallic, preferably annular, component which forms a closed conductor loop and is at different distances from the at least one inductive sensor during the rotary movement of the measurement body. According to the invention, the metallic component which forms a closed conductor loop is arranged obliquely at an angle a in the range of 0 degrees < a < 90 degrees, preferably about 10 to 45 degrees, to the plane of a board to which the inductive sensor is fitted, such that during rotation of the measurement body, the signal transmitter can Mp.No. 09/101 WO 5 March 21, 2012 be moved past the inductive sensor at a different distance, and the rotation of the measurement body can be detected electronically by inductive sampling of the rotation signal, produced during the rotation of the signal transmitter, and can be evaluated by downstream evaluation electronics. In one special embodiment the metallic component which forms a closed conductor loop has a partial formed out area facing the inductive sensor. The signal transmitter, which is in the form of a revolving metallic component which forms a closed conductor loop, may have at least two areas with different electromagnetic characteristics, and/or may be designed and/or shaped to be asymmetrical. Furthermore, the revolving metallic component which forms a closed conductor loop may also be an asymmetric ring which, for example, is mounted fixed on the flywheel, which is in the form of a measurement body, itself or on the shaft to which the flywheel is fitted, and/or is firmly clipped to or sprayed in the flywheel. In one particularly advantageous embodiment, the revolving metallic component is arranged obliquely, preferably as an angle a of about 20 degrees, to a preferably circular board on which the inductive sensor is normally mounted. In this case, the metallic component surrounds the inductive sensor and, because of its inclined position with respect to the rotation axis of the measurement body and with respect to the board, damps the inductance when its highest point is actually in the upper area of the inductive sensor, and does not damp the inductance when it is located in the lower area of the inductive sensor. The damping is in this case produced by magnetically shorting the electromagnetic alternating field. The design measures mentioned above for the configuration of the metallic annular component which runs around the inductive sensor and forms a closed conductor loop, and which are mentioned here only by way of example, advantageously result in the Mp.No. 09/101 WO 6 March 21, 2012 measurement apparatus according to the invention for detection of the rotation signals of the rotating signal transmitter operating more reliably and with improved measurement accuracy, while reducing design-dependent measurement errors, for example caused by inaccurate positioning of the inductive sensor with respect to the signal transmitter. The apparatus according to the invention can furthermore be connected to evaluation electronics which detect and evaluate the electrical signals which are produced by means of the inductive tapping of the rotation signals from the rotating signal transmitter above the inductive sensor, that is to say the number of revolutions of the signal transmitter when using an inductive sensor and/or the rotation direction of the signal transmitter when using two inductive sensors. In one preferred embodiment of the apparatus according to the invention, the measurement body is in the form of a flywheel which is attached to a flywheel shaft, and the at least one inductive sensor is in the form of a coil. The inductive sensor is connected to the surface of a preferably circular measurement board in the vicinity of the signal transmitter, and is separated from the flowing medium located in the measurement area by means of the built-in part which projects into the measurement area. On the one hand, the connecting wires of the coils can be connected to the measurement board or to a main board. The coils can also be soldered directly in the measurement board. The evaluation electronics for evaluation of the rotary movement of the measurement body and therefore also of the signal transmitter may be arranged directly on the measurement board or may be located on the main board, which is then electrically connected to the measurement board. In order to determine the number of rotation signals from the rotating signal transmitter, the measurement apparatus according to the invention has a therefore at least inductive sensor, which interacts with the rotating signal transmitter such that the evaluation Mp.No. 09/101 WO 7 March 21, 2012 electronics can detect and evaluate the number of revolutions of the signal transmitter, from the measured values that are produced. One refinement of the apparatus according to the invention, resulting from use of two inductive sensors, also makes it possible to determine the rotation direction of the signal transmitter and of the measurement body connected thereto, in addition to determination of the number of revolutions of the signal transmitter. In a further refinement, a third inductive sensor is provided on the measurement board and, in the event of a failure or faulty operation of one of the other two inductive sensors, partly takes over its function. Measurement arrangement redundancy can advantageously be achieved by means of an additional third inductive sensor which is likewise arranged on the board, in such way that the third sensor takes over the function of a failed sensor. The three inductive sensors which are now used are preferably arranged offset at an angle of 120* with respect to one another on the board. The measurement area of the water meter with the measurement body, which is preferably in the form of a flywheel, and the signal transmitter fitted thereto is separated from the dry area of the water meter by a built-in part composed of non-magnetic material, preferably plastic. The component seals the measurement area, through which a flowing medium flows, from the dry area and is used to accommodate the inductive sensor. In one advantageous embodiment, the built-in part in which the inductive sensor is arranged projects into the measurement area, such that it is sampled at the side and any tolerance fluctuation downward or upward is better absorbed. Furthermore, since it measures at the side, fluctuations in the two bearings in which the flywheel is held so that it can rotate with the flywheel shaft can be better absorbed resulting in better sampling of the signal transmitter above the inductive sensor.

Mp.No. 09/101 WO 8 March 21, 2012 The metallic component which forms a closed conductor loop surrounds the contour of the accommodating part in which the inductive sensor is arranged, and projects into the measurement area, thus resulting in the further advantages mentioned below: Greater independence from the coil material of the coil body and from the ring material located on the rotating signal transmitter is achieved, and it is also possible to use low cost iron-powder coils with less field strength. Furthermore, the measurement apparatus according to the invention makes it possible to compensate for measurement errors which occur as a result of imprecise, for example inclined, installation of the coils with respect to the signal transmitter or axial shifts which occur during the movement of the flywheel. In one refinement of the metallic component, this may also project over the area in which the coil bodies are arranged. The measurement apparatus according to the invention is preferably intended for measured-value detection in consumption meters, in particular in electronic flywheel water meters. The measurement apparatus according to the invention as well as advantageous refinements, improvements and further advantages of the invention, will be explained and described in more detail with reference to the exemplary embodiments which are illustrated in Figures 1 and 2, in which: Figure 1 shows an exemplary illustration of the measurement apparatus according to the invention for detection of rotation signals on a rotating signal transmitter, which is driven by a flowing medium, in a multi-jet flywheel meter, Mp.No. 09/101 WO 9 March 21, 2012 Figure 2 shows an exemplary illustration of the signal transmitter obliquely with respect to the rotation axis of the flywheel on a support element, and Figure 3 shows an exemplary embodiment of the signal transmitter on the support element. Figure 1 shows the measurement apparatus according to the invention for detection of rotation signals on a rotating flywheel 40, which is driven by a liquid and forms the measurement body, of a multi-jet flywheel water meter. The flywheel water meter comprises a measurement insert which is arranged in the measurement area 1 of the meter and in which a flywheel 40 is held by a flywheel shaft 30 such that it can rotate. The flywheel shaft 30 interacts with a signal or pulse transmitter 20 which is arranged in the measurement area 1, such that the latter rotates over three inductive sensors 10, which are in the form of coils, during a rotary movement of the flywheel 40. The signal transmitter 20 is in the form of a metallic preferably annular component, which forms a closed conductor loop, also referred to in the following text as a metallic closed or intrinsically closed ring 20, which is arranged obliquely at an angle a (10 degrees < a < 45 degrees), preferably about 20 degrees, to the plane of a board to which the inductive sensor is fitted, on a support element 21, such that the signal transmitter 20 can be moved past the coils 10 at a different distance. However, it has also been found to be advantageous for the ring 20 to have an inclination angle of between 10 and 45 relative to the board to which the inductive sensor is fitted. One exemplary oblique arrangement of the signal transmitter 20 with respect to the rotation axis 23 of the flywheel 40 is illustrated schematically in Figure 2. This allows the rotation of the flywheel 40 to be detected electronically by inductive sampling of the rotation signal produced during the rotation of the flywheel 40, and to be evaluated by downstream evaluation electronics.

Mp.No. 09/101 WO 10 March 21, 2012 The three coils 10 are arranged in a separate built-in part 50 whose contour projects downward into the measurement area 1 of the meter, or is curved into it, with the metallic ring 20 surrounding this contour. In consequence, the rotation signal is no longer detected directly above the coil body, but at the side on the coil body. When the flywheel 40 and the ring 20 which is connected to it rotate, one of the three coils 10 is damped alternately. In one preferred embodiment of the apparatus according to the invention, the area or the point (also referred to in the following text as the highest point) on the revolving obliquely positioned ring 20 which is closest to the coil body during the rotary movement of the measurement body 40 enters the tip of the coil body at the same height which is closest to the respectively highest point of the ring 20, since a minimal insertion of this area of the revolving ring 20 is required to achieve lateral damping of the rotation signal. The inclination of the ring 20 must in each case be appropriately adapted depending on the insertion depth of the highest point of the revolving obliquely positioned ring which is closest to the coil body during the rotary movement of the measurement body 40. Only then can the magnetic flux be effectively shorted at the point on the revolving obliquely positioned ring 20 which is at the shortest distance above the coil body during the rotary movement of the measurement body 40 with respect to the coil body. In one preferred embodiment, the lowest point on the revolving ring 20 should be at least 5mm away from the lower coil body tip, seen with respect to the board, in order that no magnetic short is created at this point. In addition, the ring 20 should be passed over the tip of the coil body, since the sensor is then no longer sampled at the side and the shorted lines of force are lost. In this case, it is optimum for the inclination, as already mentioned above, of the metallic ring 20 to Mp.No. 09/101 WO 11 March 21, 2012 be 20 degrees with respect to the plane of the board to which the coils 10 are fitted. This has been found to be advantageous for optimization of the ratio between the flow behavior in the medium of the water meter, its flow through the obliquely positioned ring 20 and the damping amplitude. An excessively low ring inclination results in the lowest point of the ring 20 likewise also damping the coil 10 which is close to it. The damping amplitude therefore becomes less. An excessively steep position of the ring 20 results in the flow in the medium being excessively influenced. The electrical signal which is produced by the measurement arrangement according to the invention is evaluated by evaluation electronics, which are not illustrated, thus detecting and evaluating the number of revolutions of the flywheel 40. In the present example, two coils 10 are required in order to identify the rotation direction of the rotating flywheel 40, thus making it possible to also determine the rotation direction of the flywheel 40 in a known manner, in the exemplary embodiment, in addition to determining the rotation speed. By way of example, this is described in DE 41 37696. The third coil 10, which is located on the measurement board, is provided as a redundancy coil and, in the event of failure or faulty operation of one of the other two coils 10, partly takes over its function. By way of example, Figure 3 shows one design embodiment of the metallic annular component 20 which revolves about the inductive sensor 10, which is in the form of a coil, with the component 20 being mounted on the end face or upper face of the support element 21, and being inclined at angle of about 20 degrees to the base surface 22 of the support element 21. In this advantageous embodiment of the metallic annular component 20, however, only a subarea of the component 20 may also be bent around in the direction of the coil bodies, or may be in the form of an angled formed-out area, such that this subarea Mp.No. 09/101 WO 12 March 21, 2012 enters the coil height. The revolving angular component 20 need no longer be positioned obliquely for this purpose, but the subarea is angled in the direction of coil bodies, in order to in each case act precisely on one of the three coils 10 which are provided and which it is currently passing over. The revolving metallic annular component 20 may be injected, clipped in or adhesively bonded by attachment elements, for example by means of the support element 21 on the flywheel 40.

Claims

1. A flywheel water meter having a measurement apparatus for detection of rotation signals with a measurement insert which is arranged in the measurement area (1) of the apparatus and in which a flywheel (40) is held by a flywheel shaft (30), such that it can rotate, having a rotating signal transmitter (20) which is arranged in the measurement area (1), interacts with the flywheel (40) and rotates over at least one inductive sensor (10) during a rotary movement of the flywheel (40), characterized in that the rotating signal transmitter (20) is a metallic component (20), which forms a closed conductor loop, is in the form of a closed ring and is at different distances from the at least one inductive sensor (10) during the rotary movement of the flywheel (40).

2. The flywheel water meter having a measurement apparatus as claimed in claim 1, characterized in that the metallic component (20) which forms a closed conductor loop is arranged obliquely at an angle a (10 degrees < a < 45 degrees) to a plane on which the at least one inductive sensor (10) is located.

3. The flywheel water meter having a measurement apparatus as claimed in one of claims 1 or 2, characterized in that the metallic component (20) which forms a closed conductor loop has a partial formed out area facing the inductive sensor (10).

4. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that the inductive sensor (10) is arranged in a built-in part (50) which projects into the measurement area (1).

5. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that the metallic component (20) Mp.No. 09/101 WO 14 March 21, 2012 which forms a closed conductor loop is arranged at an angle of about. 20 degrees to a plane on which the at least one inductive sensor (10) is located.

6. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that ferrite coils or iron-powder coils are provided as the inductive sensor (10).

7. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that the metallic component (20) which forms a closed conductor loop is formed from a first area and a second area, each of a different material type.

8. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that a subarea of the metallic component (20) which forms a closed conductor loop is bent around and/or has an angled formed-out area.

9. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that the metallic component (20) which forms a closed conductor loop is arranged obliquely with respect to a board, preferably at an angle of approximately 20 degrees, on which the inductive sensor (10) is located.

10. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that evaluation electronics are provided, which detect and evaluate the measured values produced by the rotating signal transmitter (20), that is to say the number of revolutions and/or the rotation direction of the signal transmitter (20).

11. The flywheel water meter having a measurement apparatus as claimed in one of the preceding claims, characterized in that two inductive sensors (10) are Mp.No. 09/101 WO 15 March 21, 2012 provided, whose arrangement with respect to the rotating signal transmitter (20) makes it possible to determine the rotation direction of the rotating signal transmitter (20).

12. The flywheel water meter having a measurement apparatus as claimed in claim 11, characterized in that an additional third inductive sensor (10) is provided, and takes over the function of a failed sensor (10).

13. The use of the measurement apparatus as claimed in one of the preceding claims in electronic water meters, in particular volume meters.