FLOWMETER

Description

[0001] The invention relates to a flow meter for measuring the flow of fluids in a pipeline or the like according to the preamble of patent claim 1.

[0002] Flow meters, for example, can have two ultrasonic transducers mounted at a distance from each other on a section of pipe in a so-called "clip-on solution," with both transducers acting as transmitter and receiver. The measurement signals are coupled diagonally through the pipe wall into the fluid.

[0003] The flow rate can then be determined in a conventional manner from the propagation time of the measurement signals from the transmitter to the receiver. Such flow meters are described, for example, in the publications WO 2004 / 036151 A1 and DE 10 2005 057 888.

[0004] The disadvantage of clip-on flow meters is that the measuring signals penetrate the wall of the measuring channel, so that different measuring signals are obtained depending on the material from which the measuring channel can be made, so that the influence of the material must be taken into account when evaluating the measuring signal.

[0005] Other known solutions include a measuring insert containing the ultrasonic transducers. This measuring insert is inserted into a recess in a pipe section / measuring channel, whereby the actual measuring channel can also be part of this measuring insert.

[0006] Such a solution is disclosed, for example, in DE 101 20 355 A1, wherein the two ultrasonic transducers are arranged at a distance from each other in the flow direction and on opposite sides of the measuring channel.

[0007] EP 2 306 160 A1 discloses a flowmeter / flow counter in which the measuring insert accommodates both the ultrasonic transducers and forms the actual measuring channel. This measuring insert is attached to a tangentially extending flange of a pipe section of a flowmeter housing. A profile body forming the measuring channel extends through a recess in the pipe section encompassed by the flange. This profile body influences the flow within the measuring range and additionally features reflectors for the measuring signals. In this solution, the two ultrasonic transducers are arranged in a pot-shaped housing section of the measuring insert, which is closed to the flow and immersed in it.

[0008] A similar solution is shown in EP 2 386 836 B1. In this embodiment, the measuring insert carries two ultrasonic transducers arranged offset from one another in the direction of flow. These transducers are also accommodated in a pot-shaped housing part and project into the measuring channel through an opening in a pipe section of a housing, which is encompassed by a flange. The flow guidance within the measuring channel is determined by a housing insert that can be inserted from the front side of the housing and which also carries reflectors for the ultrasonic signals, so that the ultrasound is emitted by one of the ultrasonic transducers and reflected via the reflectors to the other ultrasonic transducer, for example one located downstream. Of course, the signal guidance can also take place in the opposite direction.

[0009] EP 0 890 826 B1 describes a flowmeter in which a measuring insert is attached to a tangentially extending flange in the area of ​​a pipe section of a housing. The measuring insert carries two ultrasonic transducers that are inserted into recesses in the base of a housing part and are each sealed there by a seal. The entire measuring insert is then sealed from the flange by another circumferential seal that encloses both ultrasonic transducers. In this embodiment, too, the measuring channel is formed by a measuring insert that is inserted into the pipe section of the housing through the recess encompassed by the flange. A similar solution is described in US 8,424,392 B2 and EP 3 748 311 A1.

[0010] DE 199 44 411 A1 discloses a flowmeter in which an insert is formed in a measuring tube, giving the measuring tube an elongated cross-section. Two ultrasonic transducers are arranged offset in the flow direction on opposite sides of the measuring channel.

[0011] EP 0 650 034 A1 describes a flowmeter in which two ultrasonic transducers are arranged offset from each other. Opposite each transducer is a reflector arranged on inclined surfaces of the measuring channel.

[0012] In all the solutions described above, the reflectors are designed diametrically to the ultrasonic transducers, so that at least two reflectors must be provided to guide the ultrasonic signals.

[0013] In the flow meter according to EP 0 890 826 B1, the two ultrasonic transducers are each arranged in a sensor housing, hereinafter referred to as a coupling piece, and project radially into the measuring channel so that the fluid flows around them.

[0014] US 2013 / 167 655 A1 and DE 10 2004 061 404 A1 each disclose flow meters in which two ultrasonic sensors are arranged at an angle in a measuring housing placed on a measuring channel, which is open towards the measuring channel, so that turbulence can occur in the transition area to the measuring housing.

[0015] The disadvantage of such solutions is that either the ultrasonic transducers with their coupling piece are arranged directly in the flow, or the housing parts surrounding the ultrasonic transducers, for example, pot-shaped parts, protrude into the flow. Separation and / or vortex formation can occur at the ultrasonic transducers or housing parts that protrude into the flow or recede into the flow, which can lead to measurement errors, depending on the flow velocity, among other things.

[0016] Flowmeters in which a measuring insert is inserted axially into a measuring channel have the disadvantage of very limited geometry, as axial insertion requires that the measuring insert and the measuring channel be designed without undercuts. Furthermore, conical shapes in the inlet and outlet areas are difficult to implement, or only possible with a considerable wall thickness of the measuring insert.

[0017] EP 2 696 174 A1 discloses a flow meter with two ultrasonic sensors that are attached to a measuring channel, wherein the coupling and decoupling of the measuring signals into and out of the fluid takes place via a coupling piece that is inserted flush into the circumferential wall of the measuring channel.

[0018] WO 2018 / 011 371 A1, which originates from the applicant, describes a flow meter in which the coupling and decoupling of measuring signals from two spaced-apart measuring sensors takes place via a common coupling piece or a coupling piece each carrying the sensor(s) / transducer(s).

[0019] The parallel patent application WO 2018 / 011 372 A1 describes a flow meter with an oval or trapezoidal measuring channel.

[0020] Both flowmeter concepts ensure an improved flow through the flowmeter compared to the aforementioned state of the art with improved measurement accuracy.

[0021] The publication WO 2016 / 012024 A1 describes a flow meter with a flow-optimized measuring channel, which, however, has a very complex structure.

[0022] WO 2011 / 127934 A1 discloses a flowmeter in which the ultrasonic sensors are housed in a housing, which in turn is connected to a measuring channel via a locking mechanism. Such a flowmeter has a very complex structure, since the reflectors for redirecting the measuring beam are also formed on the housing and thus penetrate radially into the clear cross-section of the measuring channel, thus adversely affecting the flow.

[0023] EP 2 888 560 A1 describes a flowmeter in which the two ultrasonic sensors are also arranged in a closed housing that extends into a measuring channel through a radial recess. These immersed areas, in turn, disrupt the flow through the measuring channel. Furthermore, these housing areas that extend into the interior of the measuring channel serve to secure a measuring insert inserted axially into the measuring channel. This measuring insert has reflectors to deflect the measuring beams. Similar to the solutions described above, the measuring channel and the measuring insert must be coordinated to enable the axial, frontal insertion of the measuring insert.

[0024] European patent application EP 3 818 343 A1 is directed to the construction of a housing with the controller housed therein. This housing has a main PCB with a CPU and a communication circuit, housed in a module housing, which in turn is housed in the housing, which also contains a measurement PCB. The two PCBs are connected to each other via a power and communication connection, with the housing also housing a power supply for the components.

[0025] Such a housing structure is extremely complex and therefore requires considerable effort in terms of device technology.

[0026] European patent EP 2 414 789 B1 relates to a flowmeter in which the ultrasonic sensors are arranged directly on a PCB. Such a concept requires that the PCB, and thus also the sensors, be positioned very close to the flow channel to ensure sufficient signal quality, leaving little design freedom. The same applies to the concept according to EP 3 550 272 B1, in which the ultrasonic sensors are arranged on the underside of a PCB.

[0027] EP 2 888 561 B1 describes an ultrasonic flowmeter in which the electrical contact between the ultrasonic sensors is established via elastic connectors that are mechanically connected to an insulating support assembly. Such a concept also requires considerable device engineering effort. Otherwise, the disclosure of EP 2 888 561 B1 corresponds to that of the aforementioned European patent application EP 2 888 560 B1.

[0028] European patent EP 1 544 582 B1 relates to a flowmeter in which a measuring insert is also inserted axially into a measuring channel. Furthermore, it is assumed that the cross-section of the measuring channel is hexagonal, octagonal, or essentially square with rounded corners. Such a measuring insert can only be implemented with considerable equipment complexity and a corresponding design of the measuring channel cross-section.

[0029] Further prior art is known from EP 3 591 347 A1, EP 2 840 362 A1, EP 2 236 988 A1, EP 3 611 480 A1 and from US 2019 / 368 907 A1.

[0030] In contrast, the invention is based on the object of developing the flow meter with a view to further reducing the device-technical expenditure while maintaining optimal measuring accuracy.

[0031] This object is achieved by a flow meter having the features of patent claim 1.

[0032] Advantageous further developments of the invention are the subject of the subclaims.

[0033] The flowmeter according to the invention has a flow channel attachable to a pipeline through which a fluid flows, on which a measuring unit is mounted, which has at least two spaced-apart sensors designed as ultrasonic transducers that couple their measurement signals in and out through at least one recess in the flow channel. The flowmeter further has a control unit accommodated in a control housing for controlling the sensors and processing the measurement signals. According to the invention, each sensor is contacted by a contact board, which in turn is connected to a main PCB of the control unit, wherein the sensors are mounted on inclined support surfaces of a measuring channel upper section.

[0034] This design allows for very simple contacting of the sensors, which can be achieved, for example, by bonding or friction. The contact boards can be designed as separate elements. Alternatively, it is also possible to implement the contact boards as part of a plastic molded body, through which the sensor or the contact board area is electrically or signal-wise connected to the main PCB. In principle, it is also possible to connect the contact boards to the main PCB via cables or similar means.

[0035] In a particularly preferred embodiment, the contact boards are soldered or glued to the sensor, with sensor electrodes being formed in the region of a large area remote from the bottom of the control housing or the upper part of the measuring channel and / or along a peripheral wall of the sensor. This requires a special sensor design, but has the significant advantage that contact can be made easily from one side.

[0036] The relative positioning of the contact boards with respect to the sensor is particularly simple if, for example, the contact boards have locating recesses into which the housing-side locating pins engage. In reverse kinematics, it is of course also possible to position the locating pins on the contact boards and the locating recesses on the housing side, for example, on the control housing or on the upper part of a measuring channel.

[0037] In a preferred embodiment of the invention, the control housing is designed with a housing cover that provides a view of a display.

[0038] The attachment of this housing cover to the control housing is particularly simple if a multi-part sliding frame is provided, by means of which the housing cover is fixed to the control housing.

[0039] According to a further aspect of the invention, a measuring channel insert comprising an upper measuring channel part and a lower measuring channel part is connected to the flow channel via connecting bolts. The control housing can also be connected to the flow channel in this way.

[0040] The application of tools for connecting the flow meter to a pipeline is particularly easy if the control housing is tapered towards the connection nozzles of the flow channel.

[0041] According to the invention, it is preferred if the measuring channel insert and optionally also the flow channel are made of plastic.

[0042] The design of the control unit is particularly compact if a battery is contacted / attached to a large area of ​​a main PCB facing the measuring channel insert.

[0043] It is particularly preferred if the battery - depending on the battery type - is arranged with its longitudinal axis transverse or parallel to the flow direction in the control housing.

[0044] According to a further aspect of the invention, in addition to the main PCB, a display unit (EDA) and a communication module are also accommodated in the control housing, wherein these are preferably arranged approximately at a parallel distance to a housing cover offset with respect to the main PCB.

[0045] In the case where a communication module is provided, this can be designed with an integrated antenna that is covered by the housing cover.

[0046] This fastening can be done by means of a material bond, for example by gluing or by bracing.

[0047] According to a further aspect of the invention, a multi-part measuring channel insert is inserted into the flow channel in the radial direction. The measuring channel insert comprises at least one measuring channel upper part and / or one measuring channel lower part, which partially delimit a measuring channel section and are assigned an inlet and / or outlet insert that is attached to the measuring channel section. This measuring channel insert is designed such that it can be inserted into the flow channel through a radial recess in the latter.

[0048] The technical effort required for the device is minimal if both inserts are of identical design.

[0049] Adaptation to different nominal diameters of the flow channel can be achieved by exchanging the inserts, whereby the upper and lower sections of the measuring channel can remain unchanged, at least for many nominal diameters. This means that for adaptation, only the flow channel and the insert(s) are exchanged.

[0050] The positioning of the inlet and outlet inserts within the flow channel or with respect to the upper and lower parts of the measuring channel is particularly easy if the inserts are designed with an axial stop.

[0051] The inserts and the measuring channel section can be designed such that in a transition region from the fluid inlet and / or from the fluid outlet to the measuring channel, a reduction in the flow cross-section is carried out in such a way that the fluid is accelerated in this region.

[0052] To optimize the flow, guide ribs can be provided in the measuring channel, especially in the area of ​​the inlet / outlet insert.

[0053] In one embodiment, the measuring channel upper part has a housing flange to which the control housing is attached and which forms a bottom of the control housing.

[0054] In an alternative solution, the upper part of the measuring channel and the lower part of the measuring channel are attached to a base of the control housing, wherein the base, the upper part of the measuring channel and the lower part of the measuring channel together delimit at least a section of the measuring channel on the circumference.

[0055] The assembly of this module is particularly simple if the upper part of the measuring channel, the lower part of the measuring channel and the control housing are positively positioned relative to one another, in particular by means of fitting pieces / fitting recesses or the like.

[0056] The flow through the flow meter is optimal when the measuring channel section has an approximately rectangular cross-section, whereby preferably a width of the measuring channel is substantially larger in the direction of the control housing than transversely thereto.

[0057] The length of the measuring channel section can be less than 40 mm for a nominal diameter of DN110 or DN80.

[0058] According to the invention, it is preferred if at least one reflector is held, preferably by a material bond, on the lower part of the measuring channel and / or on the upper part of the measuring channel. This material bond can be achieved, for example, by overmolding the reflector during the production of the lower part of the measuring channel / upper part of the measuring channel.

[0059] Furthermore, it is advantageous if an inlet insert and / or an outlet insert is designed with a rounded cross-section on the one hand and with an approximately rectangular cross-section on the other hand.

[0060] Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. They show: Figure 1 a three-dimensional view of a first embodiment of a flow meter according to the invention; Figure 2 an exploded view of the flowmeter Figure 1 ; Figure 3 a detailed view of a measuring channel insert of the flow meter according to the Figures 1 and 2 ; Figure 4 Illustrations to illustrate the installation of sensors in the measuring channel insert according to Figure 3 ; Figure 5 a schematic diagram of the assembly of the measuring channel insert according to the Figures 3 and 4 in a flow channel; Figures 6 to 13 Schematic representations of possible cross sections of a measuring channel of a flow meter according to the invention; Figure 14 an embodiment of a flow meter in which the flow channel is made of plastic; Figure 15an exploded view of another embodiment of a flow meter according to the invention; Figure 16 a variant of the embodiment according to Figure 15 ; Figure 17 an embodiment of a flow meter according to Figure 16 , showing the structure of a control unit; Figure 18 the flow meter according to Figure 17 with attached control housing; Figures 19 the flow meter according to the Figures 17 and 18 with devices for identifying the flow meter; Figure 20 a schematic diagram of further embodiments of a flow meter according to the invention with different nominal diameters; Figure 21 an assembly sequence for contacting sensors of another embodiment of a flow meter; Figure 22 an alternative embodiment in which molded bodies are used to contact the sensors; Figure 23a variant of a flow meter in which the control unit is fixed in position to the upper part of the housing via support pins; Figure 24 greatly simplified manufacturing steps for producing a flow meter with a plastic flow channel; Figure 25 a cross-section through a flow meter to illustrate the positional fixation of a control housing with respect to a control channel; Figure 26 an alternative possibility for fixing the position of the sensors within a measuring channel upper part or a control housing; Figure 27 a three-dimensional representation of another embodiment of a flow meter; Figure 28 an exploded view of the flowmeter according to Figure 27 ; Figure 29 a sectional view of the flowmeter according to the Figures 27 and 28 ; Figures 30, 31 Individual representations of a sensor housing of the flow meter according to Figure 29 ; Figures 32, 33Individual representations of a measuring channel upper part of the flow meter according to Figure 29 ; Figure 34 a detailed view of a measuring channel lower part of the flow meter according to Figure 29 ; Figures 35, 36 Individual representations of inserts of the flow meter according to Figure 29 ; Figure 37 one Figure 30 corresponding representation with mounted sensors; Figures 38, 39 Details of the contacting of sensors in a flow meter according to the invention; Figure 40 a schematic diagram of two flow meters with different nominal diameters and tapered housings; Figure 41 Mounting options for different batteries in flow meters according to the invention; Figure 42 the assembly of display-side components in a flow meter according to the invention; Figure 43 Assembly steps for fixing a measuring housing to a flow channel; Figures 44, 45, 46 Schematic diagrams showing the possibility of positioning antennas of a communication module; Figure 47Views of a further embodiment of a flow meter according to the invention and Figures 48 , 49 an embodiment of a flow meter with a flow channel made of plastic.

[0061] Figure 1 shows a three-dimensional view of an embodiment of a flow meter 1 according to the invention with a flow channel 10 forming a measuring housing, the fluid inlet and fluid outlet formed thereon, and a control housing 8 attached thereto, which accommodates a control unit of the flow meter 1. Accordingly, the flow meter 1 is characterized by a very compact design, with the number of installed components being minimal.

[0062] The flowmeter 1 according to the invention, explained in more detail below, is characterized by a very good gearing factor (ps / l) (this factor represents the increase in flow in liters (l) over a time difference T (ps); a high gearing factor means that a higher repeatability is achieved for a measurement than with a lower value), so that signal jitter can be reduced or at least compensated for at low flow velocities. This is determined by a predetermined sensor distance and a suitable flow velocity in the flowmeter 1.

[0063] Furthermore, it is designed to minimize pressure loss during flow. This is achieved, among other things, by the continuous transitions in the measuring channel described below. Furthermore, the measuring channel is designed to eliminate any pockets, undercuts, or other obstacles where air bubbles could collect.

[0064] The flow meter 1 described below with the measuring channel optimized with regard to signal acquisition and hydrodynamics is characterized by optimal signal quality with sufficient signal strength without signal noise and without interference.

[0065] Furthermore, standard ultrasonic sensors (transducers) can be used, keeping manufacturing costs to a minimum. Flowmeter 1 can be manufactured using standard manufacturing methods.

[0066] Figure 2shows an exploded view of the flowmeter 1, with the following explanations focusing in particular on a measuring channel insert 20 and the measuring channel formed thereby. As shown, the flowmeter can be designed for pipelines with nominal diameters of DN15, DN20, DN25, or DN32; of course, the flowmeter can also be provided in other sizes.

[0067] Based on the following Figures 1 to 24 First, some basic components of different embodiments of a flow meter 1 according to the invention are explained. Further details will then become apparent from the subsequent more detailed description of further embodiments.

[0068] As shown in the exploded view Figure 2 can be removed, the flow meter 1 has the flow channel 10 - also called housing, which in the illustrated embodiment is made of brass or a metallic alloy.

[0069] This flow channel 10 has connecting pieces 12, 14, via which the flow meter 1 can be connected to a pipeline carrying the fluid. As explained in more detail below, the flow channel 10 has a radial recess 16 that opens into a flange 18, to which a control housing 32 can be attached, the structure of which will be explained in more detail below. A measuring channel insert 20 can be inserted through the radial recess 16. In the illustrated embodiment, this carries two ultrasonic sensors 22, 24, which are suitably fastened to the measuring channel insert 20. In the illustrated embodiment, the fastening is achieved, for example, by means of a sensor holder 26. The actual control unit 30 for controlling, supplying signals to, and supplying power to the sensors 22, 24 is arranged on a housing flange 28 of the multi-part measuring channel insert 20.This control unit 30 is accommodated in a control housing 32, which is opened upwards via a housing cover 34 (view according to . Figure 2 ) is closed or covered. The control unit 30 is held by a support structure 36, on which drying means 38 are also supported.

[0070] Like the Figures 1 and 2 can be removed, a display 40 which is arranged on the control unit 30 can be read through the cover 34 - this will be discussed in more detail below.

[0071] As in Figure 2 As shown below left, the flow channel 10 or the housing formed by it can be provided with different nominal diameters, whereby the actual control unit 30 with the control housing 32 and the sensors 22, 24 is designed independently of the nominal diameter. For adaptation, only a modification of the measuring channel insert 20 is required.

[0072] According to the detailed description in Figure 3The measuring channel insert 20 is formed with a measuring channel section 42, which consists of a measuring channel upper part 44 and a measuring channel lower part 46. An inlet insert 4 and an outlet insert 6 are provided on the inlet and outlet sides, each designed according to the nominal diameter of the pipeline. The measuring channel upper part 44 is further provided with the housing flange 28, to / into which the control housing 8 and the sensors 22, 24 are attached / inserted.

[0073] In In the illustrated embodiment, three reflectors 52a, 52b, 52c are inserted into the peripheral wall of the measuring channel insert 20, so that a W-shaped signal path 64 is formed.

[0074] The individual parts of the measuring channel insert 20 can be made, for example, from a fiber-reinforced plastic or another plastic material. Of course, manufacturing from a metallic material is also possible.

[0075] Figure 4shows the measuring channel insert 20 according to Figure 3 in the partially assembled state, wherein the two sensors 22, 24 are also shown, which are fastened in the housing flange 28 by means of the sensor holder 26, wherein signal lines 54, 56 of the sensors 22, 24 are led through the sensor holder 26 to the control housing 32, not shown.

[0076] In Figure 4A section through the partially assembled measuring channel insert 20 is shown at the bottom right. It can be seen that the sensor holder 26 is screwed and clamped to the measuring channel upper part 44, with recesses / pockets 59, 61 formed in the measuring channel upper part 44, into which the sensors 22, 24 are immersed with their coupling surfaces. Opposite each of the sensors 22, 24 is one of the reflectors 52a, 52b. The third reflector 52c is located between the two sensors 22, 24, so that, as explained, a W-shaped signal path 64 is established. In principle, double sensors can also be used, so that two signal paths can be realized. A V-shaped signal path is also conceivable. The profile of the measuring channel delimited by the measuring channel insert 20 will be discussed in more detail below.

[0077] According to Figure 5The multi-part measuring channel insert 20, which is preferably made of plastic, is inserted into the flow channel 10, which forms a stable housing. This stable housing can be made, for example, from a cast metal. First, the two inserts 4, 6 forming the fluid inlet and the fluid outlet are inserted into the recess 16 of the flange 18, and then the actual measuring channel section with the measuring channel upper part 44 and the measuring channel lower part 46 is inserted in the radial direction, so that the housing flange 28 of the measuring channel insert 20 rests on the flange 18 of the flow channel 10.

[0078] In the illustrated embodiment, the connecting pieces 12, 14 of the flow channel 10 are designed with a thread or other connecting elements so that the flow meter 1 can be easily attached to a pipeline.

[0079] Figure 6shows views of the measuring channel design formed by the previously described components. This measuring channel 58 is designed without undercuts or other flow obstructions that create turbulence, but cross-sectional changes are selectively designed to optimize the flow guidance between the inlet and outlet.

[0080] The sectional view shows that the measuring channel 58 has an approximately circular cross-section in the inlet and outlet areas, which can be selected according to the pipeline. The actual measuring channel section 42 with a rectangular cross-section (see top right in Figure 6) is formed centrally. According to the invention, a reduction in the flow cross-section can be provided in the region between the measuring channel section 42 and the inlet or outlet, respectively, so that the fluid flow is accelerated in this region and the cross-section of the measuring channel 58 is then enlarged in comparison to this reduction. This evens out the fluid flow in the actual measuring channel 58 and reduces turbulence, thus minimizing signal noise.

[0081] The respective transition region, in which the flow cross-section is reduced, is formed in the illustrated embodiment by a two-sided and sectionally executed conification (particularly viewed in vertical section) of the measuring channel insert 20. This cross-sectional taper is specifically formed in the transition region between the fluid inlet insert 4 and the fluid outlet insert 6 to the actual measuring channel section 42, which in turn is delimited by the measuring channel upper part 44 and the measuring channel lower part 46. The measuring beams are coupled in and out through the two recesses 60, 62 formed in the measuring channel section 42. A reflector 52a, 52b is then inserted flush into the diametrically opposite wall of the conified section.

[0082] The third reflector 52c is arranged between the two recesses 60, 62. In this region, in the illustrated embodiment, the clear width of the measuring channel 58 is again reduced compared to the largest diameter of the tapered section, so that the flow in this region is slightly accelerated.

[0083] In the Figure 6 In the detailed illustration shown at the bottom right, it can be seen that the reflector 52a is arranged opposite the associated recess 60, 62. In according to the representations Figure 6 It is clearly visible that the respective transitions between the tapered areas towards the inlet insert 4 and the outlet insert 6 and towards the measuring channel section 42 are continuous without sudden changes in cross-section, so that an optimal flow is ensured.

[0084] Figure 7shows a three-dimensional schematic diagram of the channel design, showing the positioning of the two sensors 22, 24 and the three reflectors 52a, 52b, 52c. As explained, the inclined position of the sensors 22, 24 and the previously described positioning of the reflectors 52a, 52b, 52c establish a W-shaped signal path 64, which is designed such that the measurement signals are reliably guided from the transmitter to the sensor (receiver) receiving the reflected measurement signal.

[0085] The cross-sectional profiles of the channel design are shown again using Figure 8Accordingly, the cross-section of the channel is approximately circular in the inlet and outlet areas and then tapers towards the transition area, where the circular cross-section transitions into an elongated, rectangular cross-section in which the vertical axis has a greater extension than the transverse axis running perpendicular to the plane of the drawing. The recesses 60, 62 are also circular. The support surfaces of the reflectors 52a, 52b, 52c are pocket-shaped, so that the reflectors 52a, 52b, 52c can be inserted flush into the measuring channel 58.

[0086] In the representation according to Figure 8It is also clearly visible that the clear width is smaller in the area of ​​the measuring channel section 42, so that the cross-section of the measuring channel 58 increases slightly towards the two transition areas. As explained, in these two transition areas, the cross-sectional profile changes continuously from the circular inlet insert 4 and outlet insert 6 to the approximately rectangular measuring channel 58, which is rounded in the corner area. A cross-sectional reduction is provided in the transition area to optimize flow. The applicant reserves the right to assert an independent claim based on this continuous transition.

[0087] In Figure 9 the course of the W-shaped signal path 64 is shown again.

[0088] As in Figure 10As shown, the sensor distance, ie the distance between the center axes of the sensors 22, 24 and the geometry of the measuring channel 58 is designed so that a flow that is as free from turbulence as possible with low pressure loss and an optimal gearing factor is ensured, whereby the accumulation of air bubbles is reliably prevented by the channel geometry.

[0089] The focusing of the measuring beams can be further improved if, according to the Figures 11 and 12 the reflection surfaces of the reflectors 52a, 52b, 52c and / or the coupling surfaces of the sensors 22, 24 are concavely rounded, so that optimal focusing of the measuring beams towards the reflectors 52a, 52b, 52c and the receiver-side sensor 24 is ensured.

[0090] Figure 13shows again the geometry of the previously described measuring channel 58 and the inclined sensors 22, 24 and the W-shaped reflectors 52a, 52b, 52c as well as the cross-sectional changes designed with a view to equalizing the fluid flow. Figure 13 In the embodiment shown, guide ribs 66 are formed in each insert 4, 6 in the transition area on the inlet and outlet sides, by means of which the flow in the transition area is optimized.

[0091] Figure 14 shows another embodiment of a measuring channel insert 20, wherein the area forming the actual measuring channel 58 is constructed in one piece. As in the embodiments described above, the inserts 4, 6, which form the fluid inlet and the fluid outlet, are then attached to this measuring channel insert 20. These inserts 4, 6 are again constructed identically.

[0092] Assembly is carried out as in the embodiment described above. First, the fluid inlet insert 4 and the fluid outlet insert 6 are inserted into the cast flow channel 10. In the next assembly step, the measuring channel section 42 is then inserted radially into the flow channel 10 in sections. The arrangement of the sensors 22, 24 and the reflectors 52a, 52b, 52c, as well as the course of the measuring channel 58, correspond to the previously described embodiment, so further explanations are unnecessary.

[0093] Figure 15 shows an exploded view of a variant of a flow meter 1, which in terms of construction is approximately the same as that in Figure 2, although the number of components is reduced compared to the solution described above. This is achieved in particular by contacting the sensors 22, 24 via molded bodies 68, 70, wherein the sensors 22, 24 are glued to the measuring channel insert 20, specifically to the measuring channel upper part 44.

[0094] The flowmeter 1 shown essentially consists of the flow channel 10 made of a cast material, on which the flange 18 with the recess 60 is formed. The inlet insert 4, the outlet insert 6, the measuring channel lower part 46, and the measuring channel upper part 44 are inserted through this recess, whereby for assembly, the two inserts 4, 6 are displaced radially toward the respective connection 12, 14. The flow channel 10 (housing) is connected to the measuring channel insert 20 via the connecting bolts 80. The two sensors 22, 24 are inserted into the measuring channel upper part 44, for example, by adhesive bonding. Contact is then established via the molded bodies 68, 70, whose free end sections, as explained, are contacted with the previously described control unit 30.The control housing 32 is then placed on the measuring channel upper part 44, which in turn can be provided with a housing cover 34 that provides a view of a display (EDU) 74.

[0095] In Figure 16 Views of an embodiment are shown in which the sensors (piezo elements) 22, 24 are glued to the multi-part measuring channel insert 20, wherein the contact in this embodiment is made via cables or (not shown) molded bodies 68, 70 with conductor tracks 90, 92.

[0096] Figure 17 shows an embodiment of a flow meter in which the control unit 30 and an EDU (Electronic Display Unit) 74 with the Figure 4 shown housing flange 28 of the measuring channel insert 20 is locked.

[0097] As explained above, the actual control unit 30 with a main PCB 72, an EDU 74 and possibly a communication module (not shown) (see following explanations) is locked to the above-described support structure 36, which in turn also contains the drying agent 38, which is provided on both sides of a battery 78 arranged on the underside of the PCB 72.

[0098] The support structure 36 is then fixed to the housing flange 28 of the measuring channel insert 20. This can also be done via a snap-in connection or by a screw connection or the like.

[0099] In the variant according to Figure 18The control housing 8 is connected to the housing flange 28 of the measuring channel insert 20 and the flange of the flow channel 10 via connecting bolts 80, which penetrate the housing flange 28 of the measuring channel insert 20 and a corresponding housing section of the control housing 32 as well as the flange 18, thus securing these components in position with a force-locking and positive fit. The upper cover of the control housing 8 is provided by the housing cover 34.

[0100] According to Figure 19 This housing cover 34 can be designed as a cap that is locked to the control housing 32 and carries the characteristics of the flow meter 1. In an alternative, in Figure 19 In the variant shown, a type of information plate 48 is inserted into the control housing 32 which is closed at the top.

[0101] Figure 20shows a detailed view of the flow meter 1 with the measuring channel insert 20, the flow channel 10 and a part of the control housing 8 attached thereto. The geometry of the measuring channel 58 has already been explained above. From the illustration according to Figure 20 It can be seen that for different nominal diameters, in principle only a change of the inlet insert 4 and the outlet insert 6 as well as the flow channel 10 is required.

[0102] In the embodiment according to Figure 21 The position fixing and contacting of the sensors 22, 24 is carried out via SMD spring contacts 82, which are additionally fixed in position after assembly by a material bond, for example by thermal welding.

[0103] The SMD spring contacts 82 are manufactured according to Figure 21They are mounted in such a way that they apply a preload to the sensors 22, 24, ensuring they are seated in the pockets 59, 61. After this preload, the SMD spring contacts 82 can then be heat-welded into the predetermined position. As explained in more detail below, contact boards without preload can also be used instead of the spring contacts 82.

[0104] Figure 21 shows a possible assembly sequence. As indicated, in the first step, the sensors 22, 24 are inserted into the measuring channel upper part 44. The spring contacts 82 are connected to the lines 54, 56 and are, as in Figure 21 shown on the right, placed on the sensors 22, 24 and clamped below an undercut, wherein the position of the spring contacts 82 is predetermined by reference pins 86 which dip into corresponding reference recesses 88 of the spring contacts 82.

[0105] In a subsequent process step, a material-to-material bond is created by thermal welding. In principle, the spring preload can, of course, be omitted – as explained below.

[0106] In the variant according to Figure 22 The molded bodies 68, 70 mentioned above are used for contacting, which are inserted into the measuring channel insert 20, in particular the housing flange 28 accommodating the control unit 30. The position can also be fixed by clamping the molded bodies 68, 70 and / or by means of a material bond. As shown in Figure 22As shown, the molded bodies 68, 70 are provided with corresponding conductor tracks 90, 92, which form the corresponding signal and energy paths (64). The molded bodies 68, 70 are approximately L-shaped with a flat base 94, the geometry of which corresponds approximately to that of the spring contacts 82. The conductor tracks 90, 92 are designed such that they enable contacting of the sensors 22, 24 along the direction Figure 22This enables the large surface of the sensors 22, 24 to be positioned facing the housing. Reference recesses 88 are formed on this base 94, through which reference pins 86 on the housing side are traversed. A contact arm 96 projects upwards from the base 94 in the direction of the main PCB 72, with the free end sections of the contact arms 96 then coming into contact with corresponding contacts on the main PCB 72 in order to make contact with them. The molded bodies 68, 70 are designed to be resilient, thus ensuring contact-optimized contact with the main PCB 72. In principle, this area can also be soldered or bonded in some other way.

[0107] As explained, cables or the like can also be used instead of the molded bodies 68, 70.

[0108] In Figure 22one can also see quite clearly that a housing seal 98 is arranged on the housing flange 28 between the housing flange 28 of the measuring channel upper part 44 and the control housing 32 (not shown), by means of which the control housing 8 is sealed.

[0109] In the embodiment according to Figure 23 The control unit 30 is also integrally connected to the measuring channel insert 20, specifically to the measuring channel upper part 44. In this embodiment, the sensors 22, 24 are glued to the measuring channel insert 20 in the manner described above, with contact being made via molded bodies 68, 70. Similar to the embodiment described above, in this embodiment, support pins 100 are formed on the measuring channel upper part 44, which engage in corresponding pin cutouts 102 of the main PCB 72, with the position being fixed after placement by thermal welding. In the view according to Figure 23You can also see the structure of the control unit 30, which will be explained in more detail below, with the main PCB 72, which is located underneath (view from Figure 23 ) and the EDU 74 arranged on the circuit board, as well as a communications unit if required. This will be discussed in more detail below.

[0110] In Figure 24 a further simplified embodiment is shown in which a part of the measuring channel insert 20 and the flow channel 10 which at least partially accommodates it are formed in one piece.

[0111] As in Figure 24 As shown on the left, in a first production step, a type of outer shell (outer housing) is first produced by injection molding with a fiber-reinforced thermoplastic, on which connection pieces 12, 14, the base of the flange 18 for receiving the control unit 30 and also a space for partially receiving the measuring channel insert 20 are already formed.

[0112] In a second step, the reflectors 52 are then inserted into this blank and, if necessary, further components are positioned, which are then overmolded in a third process step with a standard plastic, which does not necessarily have to be fiber-reinforced, whereby this overmold determines the contour / profiling of the previously described measuring channel 58 (see Figures 7 to 15 ). To simplify production, this plastic is designed with a comparatively low melting point, so that the outer fiber-reinforced plastic is not melted.

[0113] This housing, manufactured by injection molding, largely corresponds to the previously described flow channel 10, into which the measuring channel insert 20 with the measuring channel upper part 44 is inserted. The measuring channel lower part 46 is, so to speak, integrated into the housing (flow channel 10).

[0114] The result is an assembly manufactured in a two-stage molding process, which essentially consists of the flow channel 10 and the measuring channel base 46. The control unit 30 or the control housing 8, the sensors 22, 24, the molded bodies 68, 70, and the inserts 4, 6 are then attached in the manner described above.

[0115] Figure 25shows another detailed view showing the connection of the flow channel 10 (housing) to the measuring channel upper section 44 and the control housing 8 via the connecting bolts 80. As explained, the control housing 8 surrounds the actual control unit 30 with the battery 78, the main PCB 72, and the EDU 74. The sensors are not visible in this sectional view. Accordingly, the connection is made by the previously described connecting bolts 80, which penetrate alternating projections of the components (control housing 8, measuring channel insert 20, measuring channel upper section 44, and flow channel 10) and are sealed to the outside.

[0116] In Figure 26 is a variant of the entrance in Figure 4 The variant according to Figure 26The sensor holder 26 is not screwed, but is fixed in position by fitting bolts 103 in the flange of the measuring channel upper part 44. Otherwise, the embodiment corresponds to that of Figure 4 , so that further explanations are unnecessary.

[0117] As shown in the illustration according to Figure 8 As indicated, the length L of the measuring channel, i.e., essentially the distance between the two recesses 60, 62 or the sensors 22, 24, is relatively short compared to conventional solutions. According to the invention, for example, with nominal diameters DN of 110 or 80, the length of the measuring channel L (distance between the sensors 22, 24 or the recesses 60, 62) can be less than 40 mm, whereby the gearing mentioned above is optimized compared to conventional solutions.

[0118] Figure 27shows a further embodiment of a flow meter 1 according to the invention, which is relatively similar to the previously described embodiments. This flow meter 1 also features a cast flow channel 10 with two connecting pieces 12, 14, to which a measuring housing 2 is attached. The measuring housing 2 has a control housing 8, which is tapered towards the flow channel 10 (housing) - this will be discussed in more detail below. A housing cover 34 or a "cap" is placed on the control housing 8, which is designed with a cover 104, which in the open state (view according to Figure 27 ) provides a view of a display (EDU 74) of which, in the illustration according to Figure 7 only a display window 106 is visible.

[0119] Further components of this flow meter 1 can be seen from the Figure 28, which in turn shows an exploded view of the flow meter 1. The flow channel 10 in turn has a tangentially arranged flange 18 with the recess 16. Guides 109 for a locking mechanism, which will be explained in more detail below, are shown on the side of the flange 18.

[0120] The measuring housing 2 is designed with a multi-part measuring channel insert 20, which in principle—similar to the exemplary embodiments described above—consists of a measuring channel lower part 46, a measuring channel upper part 44, two inserts 4, 6, and a control housing 8, which together form the peripheral wall of the measuring channel 58. As will be described in more detail below, a base of the control housing 8, together with the measuring channel upper part 44 and the measuring channel lower part 46, defines the measuring channel 58.

[0121] The actual control unit 30, including the battery 78, the main PCB 72, the EDU 74, and a communications module 108, is installed in the control housing 8, which is closed at the bottom. In the illustrated embodiment, the control housing 8 has a cover flange 110, on which a cover glass 112 is supported, which is locked by means of a two-part sliding frame 114. In the closed position, this frame encompasses both the cover flange 110 and the circumference of the cover glass 112, with the two sliding frame halves being lockable together, so that the cover glass 112 is pressed with prestress against the end face of the cover flange 110 via a seal 116. The housing cover 34 with the cover 104 can also be fixed in position via this sliding frame 114. As explained at the beginning, the housing cover 34 can be provided with information about the flow meter 1 and thus acts as a kind of ID plate.The sealing of the measuring channel insert 20 against the flow channel 10 is also effected by a seal 118.

[0122] In the Figure 29 is a longitudinal section through the mounted flow meter 1 according to the Figures 27 and 28 This illustration shows the control housing 8 housing the control unit 30. The battery 78 is located on the underside of the main PCB 72 and thus supplies the electrical loads with power. The communication module 108 and the EDU 74 are arranged parallel to the main PCB 72, covered by the cover glass 112. Both the EDU 74 and the communication module 108 are connected to the main PCB 72 (also referred to as the "meterology board"), so that these elements are controlled via the PCB 72.

[0123] As explained above, the cover glass 112 rests on the cover flange 110 of the control housing 8 via a seal 116 and is held in its desired position by the locked sliding frame 114, so that the control housing 8 is reliably covered at the top. As mentioned above, in this exemplary embodiment, the control housing 8 is designed with a closed base 120, on which the two pockets 59, 61 are formed, into which the ultrasonic sensors 22, 24 are inserted. In the exemplary embodiment shown, these are glued to the base 120. Contacting is made - as will be explained in more detail later - via contact boards 124, 126, which are connected to the main PCB 72 via cables / lines 54 or via the previously described molded bodies 68, 70 with the conductor tracks 90, 92.

[0124] The measurement signals of the sensors 22, 24 are coupled into and out of the measuring channel 58 directly through the base 120 of the control housing 8. The base-side end section of the control housing 8 is inserted into the recess 60 of the flange 18 of the flow channel 10, with sealing being provided by a further seal 118 arranged between the housing base or the adjacent peripheral wall of the control housing 8 and the flange 18. The control housing 8, in particular the base 120, is connected to the measuring channel upper part 44, which is only partially visible, and the measuring channel lower part 46, which is shown in section. The structure of these components will be explained later with reference to the Figures 30 to 36 As shown in the illustration according to Figure 29As can be clearly seen, the two reflectors 52a, 52b are accommodated in recesses of the measuring channel lower part 46, while the third reflector 52c is embedded in the measuring channel upper part 44. Accordingly, a W-shaped signal path 64 results. The inlet insert 4 and the outlet insert 6 are arranged to the side of the measuring channel upper part 44 and the measuring channel lower part 46, respectively, and both extend partially into the connecting pieces 12 and 14, respectively.

[0125] The total length L of the measuring channel insert 20 with the two inserts 4, 6 and the measuring channel upper part 44 and the measuring channel lower part 46 is greater than the clear width I of the recess 16. The radial insertion is only possible due to the multi-part design of the measuring channel insert 20. The essential advantage is that no compromises have to be made with regard to the profiling as in the prior art, which has to be inserted from the front side from the inlet or the outlet. As shown in the illustration according to Figure 29 can be removed, supports 128 are also provided on the base 120, on which the battery 78 rests. In this exemplary embodiment, the described guide ribs 66 for flow optimization are also provided in the area of ​​the two inserts 4, 6. The reflectors 52a, 52b, 52c can be integrally connected to the measuring channel upper part 44 or the measuring channel lower part 46, for example, by injection molding.

[0126] Details of the components of the measuring channel insert 20 are shown in the Figures 30 to 36 explained. Figure 30 shows a top view of the control housing 8, which is directed downwards (away from the viewer in Figure 30 ) is closed by the base 120. Figure 31 shows the control housing 8 with a view of this base 120. In the illustration according to Figure 30 The cover flange 110 with a receiving space 130 for the seal 116 can be seen on top. As explained, the two pockets 59, 61 are formed in the base 120, with their base surfaces being polished in order to ensure, on the one hand, optimal coupling and decoupling of the measuring signals and, on the other hand, optimal connection of the sensors 22, 24 resting on these base surfaces. Figure 31A measuring channel adapter 132 is provided on the large, visible surface of the base 120, which enables a positive connection with the measuring channel upper part 44 and the measuring channel lower part 46. For this purpose, the measuring channel adapter 132 is designed in the central region with four fitting recesses 134, into which corresponding fitting elements of the measuring channel lower part 46 are inserted. Coupling and decoupling surfaces 136, 138 are formed to the sides of these fitting recesses 134, which can also be polished to optimize signal quality. Steps 140 are provided in the peripheral region of the measuring channel adapter 132 for positioning the measuring channel upper part 44 and the measuring channel lower part 46, so that the components of the measuring channel insert 20 can be mounted with a precise fit.

[0127] Figure 32 and Figure 33show views of the measuring channel upper part 44, which is attached to the measuring channel adapter 132. Accordingly, the measuring channel upper part 44 has two side walls 142, 144, which are connected to each other via a bracket 146. The reflector 52c is arranged on this bracket 146 between the two side walls 142, 144, wherein the reflector is preferably integrated by injection molding. In the area of ​​the side walls 142, 144, which are formed approximately with an L-shaped profile, openings 153a, 153b, 153c, 153d are formed, the spacing of which corresponds to that of the fitting recesses 134. Further fitting elements are provided along the console 146 and the side walls 142, 144, which are designed according to the measuring channel adapter 132 or the other contour of the bottom 120 of the control housing 8, so that a precise assembly of the measuring channel upper part 44 is possible.

[0128] Figure 34shows a top view of the measuring channel base 46, in whose bottom surface 149 the two reflectors 52a, 52b are embedded. The bottom surface 149 connects two walls 150, 152, which in the assembly position (see Figure 29) encompass the two side walls 142, 144 of the measuring channel upper part 44. On the longitudinal edges of the walls 150, 152 facing the observer, four locating pins 154a, 154b, 154c, 154d and further locating projections 156a, 156b are provided, which, in the assembled state, penetrate the openings 153a, 153b, 153c and 153d (the latter not visible) formed on the side walls 142, 144 of the measuring channel upper part 44 and then engage in the locating recesses 134a, 134b, 134c, 134d. The locating projections 156a, 156b engage lateral recesses 160a, 160b of the side walls 142, 144. Further relative positioning of the measuring channel upper part 44 with respect to the measuring channel lower part 46 is achieved via locating pins 162a, 162b, 162c, 162d of the measuring channel upper part 44, which engage in corresponding grooves 164a, 164b, 164c, 164d of the measuring channel lower part 46.

[0129] The inlet and outlet ends of the measuring channel insert 20 are formed by the two inserts 4, 6, which are of identical design. These inserts 4, 6 have - as can be seen from the sectional view in Figure 29 - a tapered pipe section 166, the diameter of which becomes somewhat smaller towards the actual measuring channel 58, with at least two of the guide ribs 66 being provided on the circumferential walls. At the end section facing the measuring channel upper part 44 / measuring channel lower part 46, a profile body 168 is provided, via which the round cross section of the pipe section 166 is reduced to the rectangular cross section of the measuring channel 58. This profile body 168 also projects radially beyond the outer circumference of the pipe section 166 and thus acts as an axial stop when inserting the inserts 4, 6 into the area of ​​the connecting pieces 12, 14. As can be seen from the sectional view in Figure 29can be removed, the end faces of these profile bodies 168 also rest on steps 170 of the base 120 in the assembled state, so that the measuring channel insert 20 is reliably positioned.

[0130] Figure 37 shows the open control housing 8 with a view of the base 120 with the two pockets 59, 61, in which the two sensors 22, 24 are inserted. The contacting is carried out - as explained above - via the two contact boards 124, 126 and lines 54 (cables) (not shown) or the molded bodies 68, 70. The structure of these contact boards 124, 126 is based on the Figures 38 and 39 explained.

[0131] Figure 38 shows a contact board 124 as used in the embodiment according to Figure 37 This contact board 124 has a central contact piece 170 on which conductor tracks are formed for contacting the sensor 22. This sensor 22 is designed such that both electrodes 172, 174 are arranged on the Figure 38visible large area, so that contact can be made via a corresponding design of the contact piece 170. This concept with electrodes 172, 174 formed on one side of the sensor 22 allows the latter to be connected simply by gluing to the base 120 of the control housing 8 or a measuring channel insert 20, so that contact is then made from above, ie from the side facing away from the bonding.

[0132] In the illustrated embodiment, the contact piece 170 with the conductor tracks formed thereon is connected to the electrodes 172, 174 by soldering or gluing, wherein the exact positioning of the contact board 124 is carried out via two board arms 176, 178, in each of which a fitting recess 180, 182 is provided, which in the correct reference position are penetrated by fitting pins 154 which are provided in the pockets 59, 61.

[0133] Figure 39shows a variant of the embodiment according to Figure 38 In this embodiment, the contact board 124 is designed with four board arms 176, 178, 184, 186 evenly distributed around the circumference, each of which in turn has a fitting recess 188 provided, to which corresponding locating pins 154 are assigned in the pockets 59, 61. Such a concept enables more precise relative positioning of the sensors 22, 24 with respect to the contact boards 124, 126 and also with respect to the pockets 59, 61.

[0134] Particularly with small nominal diameters and short measuring channel lengths (DN 15 / LL80), it can be difficult to reach the connecting pieces 12, 14 with the tools for connecting the flow meter 1 to the pipeline, since, for example, a wrench collides with the measuring housing 2. In order to simplify the application of a wrench or the like, an alternative inventive concept provides for the measuring housing 2 to be designed as shown in Figure 40 to the flow channel 10. In the Figure 40 Two flow meters are shown in an exploded view, in which the measuring housing 2 is not yet connected to the flow channel 10 (housing). Depending on the length (LL80 / LL110), the length l of the recess in the flange 18, through which the Figure 40visible measuring channel insert 20 can be used. This is designed according to the previously described embodiments. As shown in the illustration according to Figure 40 As is clearly visible, the control housing 8 is tapered, particularly towards the connecting pieces 12, 14, whereby the inclined wall surfaces 190, 192 of the control housing 8 simplify the application of a tool. The maximum conification depends on the length of the flow meter 1. Figure 40 In the embodiment shown on the left with a comparatively short length, the conification is more pronounced than in the case of a comparatively long measuring channel 58, as shown in Figure 40shown on the right. However, with such long measuring channels 58, the problem described above is not as significant, since the connecting pieces 12, 14 then protrude axially beyond the control housing 8, making it easier to position the tool than with short flow meters.

[0135] In principle, the aim is to install the largest possible batteries 78, as this improves the service life of the flow meter 1. Accordingly, the aim is to replace the conventional C-cell batteries with D-cell batteries with improved capacity and performance, although these are considerably larger than the more compact C-cell batteries. This is clearly shown in Figure 41shown. In the upper area, a flow meter with a comparatively short length (LL80) is shown, wherein a C-cell battery 78 is inserted into the tapered control housing 8. This is arranged in a manner known per se so that its longitudinal axis runs parallel to the flow direction of the measuring channel 58. That is, in Figure 41a ) is the front side of the battery 78 and in Figure 41b ) shows the side view of the battery 78 and also of the measuring channel 58. This illustration also clearly shows the limitation of the measuring channel cross-section by the profile bodies 168 of the inserts 4, 6.

[0136] In the Figures 41c ), 41d) show corresponding illustrations with D-cell batteries 78. Due to the significantly larger volume of these battery types, the control housing 8 must also be designed with a larger volume. Furthermore, in most cases it is necessary to orient the battery 78 according to the illustrations in Figure 41c) and 41d ) in such a way that the longitudinal axis of the cylindrical D-cell battery 78 is arranged transversely to the measuring channel axis. This means that the battery 78 must be arranged in accordance with the Figures 41c) and 41d ) by 90° compared to the position of the battery 78 in the embodiment according to the Figures 41a) and 41b ). This involves considerable additional effort, so that changing to a different battery to improve service life comes at the cost of certain disadvantages, which lie in the redesign of the control housing 8.

[0137] Based on the Figure 42The display-side closure of the control housing 8 will be briefly explained again. As described above, during the assembly of the flow meter 1, the control unit 30 with the main PCB 72 (not visible in this illustration) and the EDU 74 as well as the communication module 108 with the sensors 22, 24 and their contacting elements are inserted into the interior of the control housing 8. In the next step, as shown in Figure 42b shown, the seal 116 is inserted into the cover flange 110, the cover glass 112 is placed on top and, if necessary, the housing cover 34 (cap) is also placed on top, whereby this can, for example, be locked to the cover flange 110 in order to pre-fix the cover glass 112 and the housing cover 34.

[0138] After this pre-assembly, the sliding frame 114 with its two frame pieces is placed on the cover flange 110 and the components mounted thereon and pushed together until the two sliding frame pieces lock together and fix the housing cover 34 and the cover glass 112 in position.

[0139] The connection of the measuring housing 2 with the flow channel 10 is in Figure 43As explained above, the measuring housing 2 with the measuring channel insert 20 is inserted into the recess 16, wherein the base 120 of the control housing 8 rests on the flange 18 of the flow channel 10. The sliding frame 114 is, for example, not yet locked and the two connecting bolts 80 are not yet inserted. In the next step, the latter are connected to the force-locking and form-locking connection of the flow channel 10 with the measuring housing 2 or the control housing 8 by inserting the connecting bolts 80. In a final process step (right in Figure 43 ) the sliding frame 114 is then moved - as shown in Figure 42 explained - pushed together and locked so that all components of the flow meter 1 are reliably positioned relative to each other.

[0140] In the event that a communication module 108 is provided and this is to be provided with a powerful antenna 191, this is, as in Figure 44 shown, preferably in the control housing 8, ie positioned below the cover glass 112. It is assumed that the antenna 191 is provided with an antenna winding 193, which is in contact with the communication module 108 or the communication board 194. Due to the comparatively small installation space above the communication module 108 or the communication board 194, the integrated antenna 191 can be laid in such a way that it can be positioned above the plane defined by the EDU 74 and the communication board 194 despite the antenna winding 193 having a comparatively large diameter. That is, according to the embodiment in Figure 44 On the left, the antenna winding 193 is arranged laterally in the area of ​​the EDU 74. In the embodiment according to Figure 44On the right, the antenna winding 193 is arranged in the area of ​​the communication board 194, with the antenna wire initially running laterally around the communication board 194 and the EDU 74 located next to it.

[0141] In the Figures 45 and 46 An alternative solution is shown. In this variant, the antenna 191 does not have to be integrated flush, but can protrude beyond the control housing 8. The antenna winding 193 is arranged vertically to the large surface of the communication board 194, although according to Figure 46 to protect against external damage to a housing cover 34, which covers the control housing 8 upwards (view from Figure 46 ), an outwardly closed antenna receptacle 196 is designed, into which the antenna winding 193 is immersed, so that the antenna 191 is covered to the outside, but has an optimal transmission-reception behavior due to the vertical arrangement.

[0142] In this embodiment, the housing cover 34 is provided with a display window 106, with a cap 198 additionally mounted on the housing cover 34, which acts, for example, as an ID plate or can be provided with other information. This cap 198 has a recess 200 through which the antenna receptacle 196 extends, with the antenna winding 193 arranged therein. Otherwise, the Figure 45 The embodiment shown corresponds to the previously described embodiments, so that further explanations are unnecessary.

[0143] In Figure 47 A further embodiment of a flow meter 1 is shown, in which, in a modification of the previously described embodiments, the measuring channel upper part 44 is integrated into the control housing 8. In other words, the fitting elements of the measuring channel upper part 44 are in the embodiment according to Figure 47at the bottom 120. These fitting elements are shown in the illustration according to Figure 47 are provided with the reference number 200 for example and are complemented by the measuring channel lower part 46 to form the measuring channel 58 or the measuring channel insert 20, which, as shown in Figure 47 is inserted into the recess 16 in the flange 18 of the flow channel 10 on the right. In this embodiment, the two reflectors 52a, 52b are also provided in the measuring channel lower part 46, while the fitting elements 200 also accommodate the reflector 52c, so that a W-shaped signal path 64 can again be realized.

[0144] Assembly is similar to the embodiments described above. In a first method step, the two inserts 4, 6 are inserted through the recess 16 into the flow channel 10 and displaced in the axial direction toward the connecting pieces 12, 14, creating space for inserting the measuring channel insert 20 with the measuring channel lower part 46 and the fitting elements 200 formed on the base 120 of the control housing 8. Upon insertion, the elements held on the control housing 8 (fitting elements 200 and measuring channel lower part 46) complement the inserts 4, 6 to form the measuring channel insert 20, with the seal 116 providing external sealing.

[0145] When changing the nominal diameter, in principle only the flow channel 10 and the inserts 4, 6 have to be replaced, while the other components can be retained.

[0146] In the above-described embodiments, the control housing 8 and the measuring channel insert 20 are made of a different material than the flow channel 10. The latter is typically made of a cast alloy, for example, brass.

[0147] In the Figures 48 , 49 An embodiment is shown in which a composite flow channel 10 is connected to the control housing 8, so that in principle a flow meter 1 is provided, the essential components of which consist of very light and durable fiber-reinforced plastic or another composite material. The production of this flow channel 10 made of a composite material can be carried out using a multi-stage injection molding process, as is shown, for example, in the Figure 24 has been described, so that further explanations are unnecessary.

[0148] In the previously described embodiments, individual molded bodies 68, 70 are provided for each contact of a sensor 22, 24. In principle, these molded bodies 68, 70 can also be combined to form profile parts, so that both sensors 22, 24 are contacted via a common profile body, which is equipped with different conductor tracks 90, 92 to enable individual control of the sensors 22, 24.

[0149] A flow meter with an optimized flow cross-section is disclosed. List of reference symbols:

[0150] 1Flowmeter 2Measuring housing 4Inlet insert 6Outlet insert 8Control housing 10Flow channel 12Connecting nozzle 14Connecting nozzle 16Recess 18Flange 20Measuring channel insert 22Sensor 24Sensor 26Sensor holder 28Housing flange 30Control unit 32Control housing 34Housing cover 36Support structure 38Desiccant 40Display 42Measuring channel section 44Measuring channel upper section 46Measuring channel lower section 48Information plate 52Reflector 54Line 56Line 58Measuring channel 59Pocket 60Recess 61Pocket 62Recess 64Signal path 66Conductive rib 68Form body 70Form body 72Main PCB 74EDU 78Battery 80Connecting bolt 82 SMD spring contact 86 Reference pin 88 Reference recess 90 Conductor track 92 Conductor track 94 Base 96 Contact arm 98 Housing seal 100 Support pin 102 Pin cutout 103 Fitting bolt 104 Cover 106 Display window 108 Communication module 109 Guide 110 Cover flange 112 Cover glass 114 Sliding frame 116 Seal 118 Seal 120 Base 124 Contact board 126 Contact board 128 Support 130 Mounting space 132 Measuring channel adapter134 Recess 136 Coupling surface 138 Output surface 140 Step 142 Side wall 144 Side wall 146 Bracket 148 Recess 149 Base surface 150 Wall 152 Wall 153 Opening 154 Dowel pin 156 Dowel projection 160 Recess 162 Dowel pin 164 Groove 166 Pipe section 168 Profile body 170 Contact piece 172 Electrode 174 Electrode 176 Board arm 178 Board arm 180 Recess 182 Recess 184 Board arm 186 Board arm 188 Recess 190 Wall surface 191 Antenna 192 Wall surface 193 Antenna winding 194 Communication board 196Antenna holder 198Cap 200Fitting element 200Recess

Claims

1. A flow meter with a flow channel (10) that can be attached to a pipe through which a fluid flows, on which a measuring unit is held, which has at least two sensors (22, 24) spaced apart from each other and designed as ultrasonic transducers which couple their measuring signals in and out through a recess (16) in the flow channel (10), and a control unit (30) housed in a control housing (8) for controlling the sensors (22, 24) and for processing the measuring signals, characterised in that each sensor (22, 24) is contacted by a respective contact board (124, 126) which in turn is connected to a main PCB (72) of the control unit (30), wherein the sensors (22, 24) are fastened to inclined support surfaces of a measuring channel upper part (44).

2. The flow meter according to claim 1, wherein the sensors (22, 24) or the contact boards (124, 126) are contacted via lines (54) or via moulded bodies, in particular plastic moulded bodies (68, 70) with conductor tracks (90, 92).

3. The flow meter according to claim 1 or 2, wherein the contact plates (124, 126) are soldered or glued to a respective sensor (22, 24), wherein sensor electrodes (172, 174) are formed in the area of a large surface remote from the bottom (120) of the control housing (8) or of an upper part (44) of the measuring channel and / or along a peripheral wall of the sensor (22, 24).

4. The flow meter according to one of claims 1 to 3, wherein the contact plates (124, 126) are each positionally fixed in relation to the control housing (8) or the upper part of the measuring channel (44) in a form-fitting manner, in particular by means of fitting recesses and fitting pins (154) engaging therein.

5. The flow meter according to one of the preceding patent claims, wherein the control housing (8) has a housing cover (34) which allows a view of a display (40) (EDU 74).

6. The flow meter according to patent claim 5, wherein the housing cover (34) is connected to the control housing (8) via a multi-part sliding frame (114).

7. The flow meter according to one of the preceding patent claims, wherein the control housing (8) is tapered towards the connection pieces (12, 14).

8. The flow meter according to one of the preceding patent claims, wherein a battery (78) is contacted / fastened to a large surface of a main PCB (72) facing the measuring channel insert (20).

9. The flow meter according to patent claim 8, wherein the battery (78) is arranged with its longitudinal axis transverse or parallel to the flow direction of the control housing (8).

10. The flow meter according to one of the preceding patent claims, wherein the control housing (8) also accommodates a display unit (EDU 74) and a communication module (108), which are arranged together at approximately parallel distances offset towards a housing cover (34) with respect to a main PCB (72).

11. The flow meter according to claim 10, wherein the communication module (108) is designed with an antenna (191) integrated into the control housing (8), which is covered by the housing cover (34).

12. The flow meter according to claim 1, wherein the fastening is made by a material bond, preferably by gluing or by clamping.

13. The flow meter according to one of the preceding patent claims, with an inlet insert and / or an outlet insert (4, 6) which are attached to the measuring channel section (42) and are also inserted through the recess (16), wherein the measuring channel section (42) is preferably essentially delimited by a measuring channel lower part (46) and a measuring channel upper part (44) or the control housing (8).

14. The flow meter according to claim 13, wherein both inserts (4, 6) are identical in construction.

15. The flow meter according to claim 13 or 14, wherein the measuring channel lower part (46) and / or the measuring channel upper part (44) remain the same for different nominal diameters (DN) of the flow channel (10) and adaptation to the nominal diameter (DN) is effected via the inserts (4, 6).