ULTRASONIC FLOW METER

Description

[0001] The invention relates to an ultrasonic flowmeter comprising a housing and a channel on the housing side for passing a fluid whose flow is to be measured. The flow measurement is carried out using ultrasound; for this purpose, at least one ultrasonic transducer is arranged on a wall within the housing that defines the channel.

[0002] Such ultrasonic flow meters are state-of-the-art and are typically used to determine the domestic water consumption of residential units or other consumers, but also as part of heat meters, where heat consumption is determined based on the flow rate and the temperature difference.

[0003] The invention is based on prior art as known from EP 3 550 272 B1. This describes an ultrasonic flow meter with a housing having a channel passing through the housing, which is intended for the passage of a liquid. The flow rate flowing through this channel is determined by ultrasonic measurement. For this purpose, two ultrasonic transducers are provided, one of which functions as an ultrasonic transmitter and the other as an ultrasonic receiver, and which are located on the wall within the housing that defines the channel. The ultrasonic transducers are each arranged on sections of a common circuit board that is integrated within the housing and which accommodates the electrical and electronic components.The ultrasonic transducers are arranged on circuit board sections that are limitedly movable relative to the rest of the circuit board, allowing the ultrasonic transducers to be subjected to spring force by coil springs acting on the circuit board. The springs are each suspended from a rear support element, which, together with the circuit board, is attached by two screws to pins protruding from the housing base, with the screws engaging in these pins. The housing is closed by a cover that is welded to the housing around its circumference. DE 10 2006 015 217 A1, DE 25 26 817 A1, and DE 10 2006 015 218 A1 each describe clamp-on ultrasonic flowmeters. US 2017 / 0314978 A1 describes an ultrasonic flowmeter with a housing that is attached to a flow tube.

[0004] For the sound coupling between the ultrasonic transducers and the duct, it is crucial that the ultrasonic transducers are pressed against the wall with sufficient force, ensuring this is maintained even during temperature fluctuations and over long operating periods of, say, 15 or 20 years. On the other hand, such ultrasonic flow meters are devices that are manufactured in large quantities, and even small improvements, whether in manufacturing or assembly, can lead to significant savings.

[0005] Against this background, the invention according to the application is based on the object of improving an ultrasonic flowmeter of the type mentioned above. Furthermore, a method for generating a contact force between an ultrasonic transducer and a channel wall of an ultrasonic flowmeter is to be provided, which ensures a simple and reliable, long-term stable application of force.

[0006] The device-related part of this object is achieved by an ultrasonic flowmeter having the features specified in claim 1. Advantageous embodiments of the invention can be found in the following description, the claims, and the drawings.

[0007] The ultrasonic flow meter according to the invention comprises a housing and a channel on the housing side for conducting a fluid whose flow is to be measured. For this purpose, at least one ultrasonic transducer is arranged on a wall within the housing that defines the channel. According to the invention, the at least one ultrasonic transducer is secured within the housing by means of at least one non-detachable snap and / or clamp connection.

[0008] The ultrasonic flow meter according to the invention is particularly intended for detecting the flow rate of a liquid. For this purpose, a channel is provided on or in the housing, as well as at least one ultrasonic transducer, which is arranged on a wall delimiting the channel, directly or indirectly within the housing. The channel is either part of the housing, but is sealed both from the interior of the housing and from the environment, or is formed by a tube that passes through the housing or at least leads with part of its wall into the interior of the housing, so that an ultrasonic transducer can be attached there in such a way that ultrasonic waves can be transmitted to the liquid and vice versa. In principle, at least one ultrasonic transducer is required for the measurement; in practice, the arrangement of two ultrasonic transducers, one functioning as a transmitter and the other as a receiver, or vice versa, has proven successful.In order to quickly and easily secure the ultrasonic transducer within the housing, the invention provides for a snap and / or clamp connection within the housing. This non-detachable connection reliably and with long-term stability secures the ultrasonic transducer within the housing in a simple assembly step, particularly in contact with the wall defining the channel. The connection is preferably a snap and clamp connection, but with a suitable design, a snap or clamp connection may also be sufficient to achieve this.

[0009] In contrast to the prior art, with a suitable design of this snap and clamp connection, the ultrasonic transducer(s) can be fixed within the housing by a simple plug-in process; rotating tools as is required for the screw connections provided in the prior art can be omitted.

[0010] The method according to the invention enables the generation of a contact force between, for example, a piezoelectric ultrasonic transducer and a channel wall of the ultrasonic flowmeter by attaching the ultrasonic transducer using a snap-in and / or clamp connection and simultaneously applying a spring force. Because the attachment is accompanied by a spring force, a long-term stable contact force is ensured without the need for separate installation of the required spring means. The preload required to generate the spring force is generated in a single operation during the attachment, which is advantageous.

[0011] It is particularly advantageous if at least one clamping pin is provided for each ultrasonic transducer within the housing, and if each ultrasonic transducer is secured to the clamping pin with a clamping spring washer. Preferably, a pair of clamping pins is provided for each ultrasonic transducer and is arranged on either side of the ultrasonic transducer. These pins can be formed so as to rise vertically from the housing base, particularly if the housing is designed as an injection-molded component, as will be described in more detail below. If, as is typically the case with ultrasonic flow meters of this type, two ultrasonic transducers are provided in the housing near the ends of the channels, then they are advantageously fastened by means of four clamping pins, each in pairs on one side. These clamping pins can also advantageously be used to secure the circuit board, which carries the electrical and electronic components, within the housing.The clamping pins can be cylindrical, slightly conical, or even have a square cross-section, depending on the spring clamping washer used. Clamping spring washers are state of the art, but are typically not necessarily made of metal. They usually have a circumferentially closed ring body from which flat, inwardly projecting spring tongues protrude. When pushed onto the clamping pin, these tongues are clamped in the axial direction of the pin and exert a certain spring effect. The connection is designed as a non-detachable connection and can, if necessary, be supported by locking recesses in the pin, for example, circumferential grooves at a short axial distance from one another. The pin diameter is always slightly larger than the free passage within the spring clamping washer, creating both a clamping and a spring effect when pushed on.

[0012] The ultrasonic flowmeter usually has a circuit board with electrical and electronic components within the housing, as well as a cover that closes the housing, as is conventional. According to a further development of the invention, an intermediate housing is advantageously provided within the housing. This intermediate housing is arranged between the housing cover and the circuit board in the housing, is secured within the housing by means of a clamping spring, and accommodates spring means for applying force to the at least one ultrasonic transducer and the clamping spring washers, preferably holding them in a form-fitting manner.Such an intermediate housing is particularly advantageous in terms of assembly technology, since it can be inserted into the housing together with the spring means for applying force and the clamping spring washers incorporated therein in one operation, and at the same time the ultrasonic transducers and the circuit board are fastened within the housing and the spring force for pressing the ultrasonic transducers against the channel wall is generated.

[0013] The intermediate housing is advantageously made of plastic, typically as an injection-molded plastic part, wherein the spring means and the clamping spring washers are preferably made of metal and are positively integrated into the intermediate housing or between the housing and the intermediate housing. In this way, the circuit board and intermediate housing can be secured in the housing in a single operation. The circuit board carries the ultrasonic transducers, each of which is arranged on a circuit board section with limited movement, which is pressed against the channel wall by the spring means in the axial direction of the ultrasonic transducer. The spring means for applying force to an ultrasonic transducer can be designed in a known manner as helical springs, which are then advantageously arranged on the intermediate housing side, so that separate assembly within the housing can be omitted.

[0014] However, it is particularly advantageous if the spring means for applying force to an ultrasonic transducer and the means for clamping the intermediate housing are formed as a single piece. This can advantageously be achieved by a spring clip comprising a pressure spring for an ultrasonic transducer and at least one clamping spring washer. This spring clip is preferably designed as a spring plate, which is shaped to apply spring force to the ultrasonic transducer, thus pressing it against the channel wall in the installed position, and to form the clamping spring washer.Such clamping spring washers can easily be formed in the ends of the brackets, so that only one spring component, namely a spring plate designed as a spring bracket, is required for each ultrasonic transducer, which is advantageously incorporated laterally into the intermediate housing before assembly, in order to then be mounted together with it by simply pressing it on.

[0015] In principle, such a spring clip can have a clamping spring washer and can otherwise be designed to provide the required clamping force for the ultrasonic transducer. However, two clamping spring washers are preferably formed in the spring clip to ensure symmetrical force application to the ultrasonic transducer and secure attachment.

[0016] To secure such a spring clip to the intermediate housing, it is advantageous to provide a pair of tongues on the intermediate housing, preferably two such open pairs of tongues diametrically opposed, each of which positively accommodates a spring clip and, when assembled, is penetrated by the pair of clamping pins on the housing side. The clamping fastening is thus achieved via the clamping spring washers formed in the clips. Since the spring clip is positively secured between the radial tongues, on the one hand, the spring clip is secured to the intermediate housing for the purpose of assembly, and on the other hand, after the intermediate housing is pressed in with the spring clips, these components are integrated into the housing in their intended position and function.

[0017] Advantageously, a spring clip is designed such that it has a central section which, viewed from the side, is U-shaped, the web of which acts on the ultrasonic transducer or the circuit board section on which the ultrasonic transducer is arranged. The free leg ends of the U-shaped central section are bent transversely outwards, then each merge into a section running parallel to the leg and are bent with their free end section towards the leg, with each end section being designed as a clamping spring washer. With this design, the entire clip is used as a spring to generate the contact force of the ultrasonic transducer against the channel wall, whereas the clamping spring washers formed in the end sections serve to clamp the spring clip and the intermediate housing, in which they are positively integrated, including the circuit board arranged between the housing base and the intermediate housing.

[0018] In an alternative embodiment, the spring clip also has a central section which is U-shaped in side view, the web of which acts on the ultrasonic transducer or the circuit board section on which the ultrasonic transducer is arranged, but then merges with the free leg ends of the U into a section which is bent outwards by 180° in order to then have end sections with the end leg ends directed towards or away from the leg, which are also designed as clamping spring washers and which are arranged approximately parallel to the web.

[0019] In an alternative embodiment, the legs of the U-shaped central section are designed to taper inwards and the free leg ends of the U are bent diagonally outwards and upwards, then each transitioning into a section running parallel to the leg, with their free end section bent towards the leg, where the clamping spring washers are formed. The variation in the shape of the bracket allows for virtually any adjustment of spring force and spring travel as well as the characteristic curve of the spring. The spring brackets described above are to be understood only as examples; the invention is not limited to a spring bracket with a U-shaped central section, but this arrangement is particularly advantageous due to its design.

[0020] To influence the spring characteristic of the bracket, the sheet metal can be designed with different thicknesses in certain sections. However, it is easier to manufacture by using a sheet metal of essentially constant thickness and providing recesses in certain sections, particularly in the areas between the central U-shaped section and the end sections. This allows the spring to be made softer without reducing the required clamping force in the area of ​​the clamping spring washers.

[0021] In principle, the ultrasonic transducer(s) can be arranged as individual components; however, it is particularly advantageous to arrange them on the circuit board side, as this simplifies installation and electrical wiring. To ensure the necessary mobility, it is advantageous to provide a circuit board section for each ultrasonic transducer that has limited mobility relative to the rest of the circuit board. This section is typically only connected to the rest of the circuit board by an elongated arm, so that this section is elastically movable on the circuit board. The ultrasonic transducer is advantageously attached to this circuit board section using a permanently elastic, electrically conductive adhesive, which ensures electrical contact on the one hand and attachment to the circuit board section on the other.The permanent elasticity ensures that even after years of use, no embrittlement occurs and thus the desired bond is maintained mechanically and electrically.

[0022] Piezoelectric transducer elements are advantageously used as ultrasonic transducers. These are typically cylindrical in shape and can be contracted at their two opposite ends. Such ultrasonic transducers are advantageously electrically and mechanically connected to the circuit board or circuit board section at one end and can be electrically connected to the circuit board at the other end via separate wiring. This electrically conductive connection between the end of the ultrasonic transducer facing away from the circuit board and the circuit board can advantageously be made via the spring clip. Since this is typically made of metal, it is electrically conductive, and the spring force applied also ensures reliable contact.

[0023] Advantageously, a water-absorbing agent, such as a water-absorbing plastic or desiccant granules, is provided within the housing of the ultrasonic flowmeter to bind the moisture diffusing through the plastic housing wall. This water-absorbing agent is advantageously arranged within the intermediate housing. It can be accommodated there like a tray, which is particularly advantageous when accommodating granules.

[0024] For ultrasonic flow meters, such as those used to measure water consumption or heat quantities, it is state-of-the-art to wirelessly transmit the measurement results to a receiver at regular intervals. For this purpose, an antenna is provided inside the housing or on the edge of the housing to ensure a sufficiently large transmitter range with a comparatively low electrical power. Such an antenna is advantageously located inside the intermediate housing, for example, on a peripheral section of the intermediate housing.

[0025] A cup-shaped housing design is advantageous because, with appropriate contouring of the circuit board and intermediate housing, they are held in place with a positive fit and are secured within the housing after the clamping spring washers are attached. The channel in which the flow is measured is formed integrally with the housing. It is particularly advantageous if the channel is integrated into the housing at the bottom, as this allows for optimal use of the housing space.

[0026] To operate the ultrasonic transducers, evaluate the measurement results, and transmit the data, the ultrasonic flowmeter requires electrical power, which is provided by batteries integrated into the housing, typically located underneath the circuit board next to the channel. The batteries power the device for a long period of time, at least long enough for no recalibration or intervention to be required within this period, making it practical to design the device as a disposable item. In this case, it is particularly advantageous if the cover is tightly welded to the housing to reliably protect the components inside the housing from external environmental influences.

[0027] If, as is advantageous, the circuit board is equipped with a display on the side facing the intermediate housing, it is advisable to provide a recess in the intermediate housing aligned with the display and to make the cover transparent in this area, aligned with the display, so that the display can be viewed when the cover is closed. Alternatively, a transparent window can also be formed in the intermediate housing, aligned with the display.

[0028] The invention is explained below with reference to exemplary embodiments illustrated in the drawings. They show: Figure 1 shows a highly simplified schematic exploded view of the circuit board, the intermediate housing and the cover of an ultrasonic flow meter. Figure 2 shows the housing of an ultrasonic flow meter with integrated circuit board and an intermediate housing with cover in an exploded view. Figure 3 shows a first embodiment of an intermediate housing in a perspective view obliquely from below. Figure 4 shows the intermediate housing according to Figure 3 in perspective view with the closing cover, Figure 5 the intermediate housing according to Figure 3 with lid in side view, Figure 6 a section along the section line LL in Figure 5 , Figure 7another design of an intermediate housing with spring clips and cover in exploded view, Figure 8a side view of the components according to Figure 7 assembled, Figure 9 a perspective view of the spring clip according to Figure 7 , Figure 10 a side view of the spring clip according to Figure 9, Figure 11 another design of a spring clip in perspective view, Figure 12 a side view of the spring clip according to Figure 11 , Figure 13 a perspective view of a further embodiment of a spring clip, Figure 14 a side view of the spring clip according to Figure 13 , Figure 15 a perspective view of a further embodiment of a spring clip and Figure 16 a side view of the spring clip according to Figure 15 .

[0029] The embodiments of an ultrasonic flowmeter illustrated in the figures are an electronic water meter whose basic structure and function are described in EP 3 550 272 B1, to which reference is made in this regard. It comprises a pot-shaped housing 1, which is designed as a plastic injection-molded part and, in the region of the housing base, has a channel 2 penetrating the housing 1, with an inlet connection 3 and an outlet connection 4, which are intended for integration into a water pipe whose flow rates are to be measured with the ultrasonic flowmeter. In the embodiment illustrated, the housing 1, channel 2, and the inlet and outlet connections 3, 4 are designed as a single-piece plastic injection-molded part.

[0030] A circuit board 5 is incorporated into the housing 1, which carries the electrical and electronic components of the flowmeter. A display 6 is arranged on the upward-facing side of the circuit board 5, and two batteries are arranged on the underside, which, when installed, are located on either side of the channel 2. The circuit board 5 has circuit board sections 8 on two diametrically opposite sides. These sections are movable to a limited extent relative to the rest of the circuit board and are connected to the circuit board 5 only by means of an arm 9. These circuit board sections 8 each carry a piezoelectric ultrasonic transducer 10 on their underside.

[0031] In the installed position, these ultrasonic transducers 10 are located near the ends of the channel 2 on the channel wall; for this purpose, corresponding recesses are provided on the wall side, which fix the ultrasonic transducer 10 with its front side and laterally in a form-fitting manner.

[0032] The circuit board 5 and the ultrasonic transducers 10 resting against the channel wall of the channel 2 are secured in the axial direction by an intermediate housing 11 within the housing 1, both positively and non-positively. The outer contour of the intermediate housing 11 is adapted to the inner contour of the housing 1 and has a recess 12 on the circuit board 7 that is aligned with the display 6. A transparent section 13 is provided in a cover 14 that is aligned with the recess, allowing the display 6 to be read from outside the housing 1.

[0033] The intermediate housing 11 has, in the area aligned with the circuit board sections 8, recesses for receiving coil springs 15 which, in the installed position, exert a contact force on the circuit board sections 8 and thereby apply force to the ultrasonic transducers 10 in the direction of the channel wall of the channel 2 in order to ensure good acoustic coupling and decoupling into the channel 2 and the water conducted therein.

[0034] Furthermore, within the intermediate housing 11, next to the coil springs 15, there is a pair of clamping spring washers 16, which are provided for snapping and clamping the intermediate housing 11 while integrating the circuit board 5 within the housing 1. For this purpose, clamping pins 17 projecting from the bottom of the housing 1 are provided, which are arranged in pairs such that they penetrate the circuit board 5 such that one clamping pin 17 of a pair of clamping pins is arranged on one side and the other clamping pin 17 of a pair of clamping pins is arranged on the other side of a circuit board section 8 or an ultrasonic transducer 10.

[0035] The intermediate housing 11, which is closed at the top by the cover 14, has cavities 18 on the sides of the recess 12, which are provided for receiving desiccants and are closed by the cover 14. Furthermore, an antenna 32 is integrated into the intermediate housing.

[0036] The coil springs 15 and the clamping spring washers 16 are arranged in the intermediate housing 11 in such a way that the intermediate housing 11, together with these components, can be integrated from above into the housing 1 above the circuit board 5 as a single piece, together with the cover 14 (or without the cover if the cover is installed later). After appropriate alignment, the intermediate housing 11 is pressed into the housing 1 with sufficient contact force. The clamping spring washers 16 are penetrated by the free ends of the clamping pins 17 and permanently clamp the intermediate housing and integrate the circuit board 5 within the housing 1. The fastening is achieved purely by compressive force, i.e. without tools, with a predetermined contact force until the intermediate housing has reached its intended position within the housing 1. This position is permanently fixed by the clamping spring washers 16 on the clamping pins 17.In the illustrated design, the clamping pins are cylindrical and smooth, but they can be provided with a large number of circumferential grooves in order to fulfill a snap-in function in addition to the clamping function.

[0037] In this intended position of the intermediate housing, the coil springs 15 are preloaded and collapsed into the intermediate housing 11. Their free ends press against the circuit board sections 8, on the underside of which the ultrasonic transducers 10 are arranged, so that they effectively press the ultrasonic transducers axially toward the wall of the channel 2.

[0038] The cover 14 is snap-fitted into the intermediate housing 11 and can be fitted before or after the intermediate housing 11 is inserted into the housing 1. Finally, the cover is welded circumferentially to the housing 1, so that the interior of the housing is hermetically sealed from the environment.

[0039] The intermediate housing 11 has a side wall which is arranged close to the inside of the housing 1 with little play. Figures 2 and 7 to 8 In the intermediate housing 11a shown, the side wall is arranged at a significant distance from the interior of the housing 1 and has a collar 19 bridging this gap. The essential difference between the intermediate housing 11a and the intermediate housing 11 lies in the design and arrangement of the clamping spring washers and the springs for generating the contact force of the ultrasonic transducers 10.

[0040] In the intermediate housing 11a, radially projecting tongues 20 are provided on both sides, approximately in the area where the channel 2 runs through the housing 1 and where the coil springs 15 and clamping spring washers 16 are arranged in the intermediate housing 11, which serve to receive spring clips 21. As the Figures 7 and 8As can be seen, the tongues 20 are arranged in pairs, have a cuboidal flat shape, each have a central recess 22 and are reinforced on their upper side with a ring section 23, which continues the recess 22 in alignment. This arrangement serves to accommodate the spring clip 21, which is Figures 9 and 10 is shown enlarged.

[0041] This spring clip 21 is formed from a strip-shaped spring sheet and has in side view ( Figure 10) a central, essentially U-shaped section with a web 24 and two legs 25, which in this embodiment converge slightly obliquely upwards, and then project diagonally to the side and upwards at an angle of 90°. These sections 26 merge into sections 27, which in the installed position are directed downwards, i.e., towards the housing base, and whose free end sections 28 extend towards the legs 25. These end sections 28 are designed as clamping spring washers, as can be seen in particular from Figure 9can be seen. These end sections 28 thus have an annular part 29 from which radially inwardly projecting segment sections 30 extend. The segment sections 30 form spring tongues, their ends forming a circular ring that is smaller than the outer circumference of a clamping pin 17. These spring clips 21 are incorporated laterally into the intermediate housing in such a way that the tongues 20, with the annular sections 23, engage in the free space formed between the end sections 28 and the sections 26 and hold the spring clip 21 there.

[0042] The spring clips 21, with their end sections 28, which are designed as clamping spring washers, assume the function of the clamping spring washers 16 in the previously described embodiment. Unlike the previously described embodiment, however, a separate spring 15 is not used to generate a contact force acting on the ultrasonic transducer 10; instead, the spring action of the spring clip 21, in particular the inclined legs 25 and the adjoining sections 26, is utilized. The sections 26 are provided with recesses 31, which serve to adjust the spring core line, in this case, in particular, to make the spring softer.

[0043] The spring clips 21 are therefore first incorporated laterally into the intermediate housing 11, which is then placed together with the spring clips onto the clamping pins 17 within the housing 6, enclosing the circuit board 5. By pressing the intermediate housing 11a toward the housing base of the housing 1, the intermediate housing 11a is clamped onto the clamping pins 17 by means of the clamping spring washers formed in the end sections 28, wherein the remaining part of the spring clip 21 compresses axially and is thus prestressed in order to exert a spring force on a circuit board section 8 on which the ultrasonic transducer 10 is arranged, in order to press the ultrasonic transducer 10 against the channel wall.

[0044] Based on the Figures 11 and 12A spring clip 21a is shown, which also has a central section that is U-shaped in side view, the web 24a of which is approximately perpendicular to the legs 25a. However, the leg ends there continue in a section 26a that is bent circularly by 180°, at the ends of which inwardly projecting end sections 28a are formed, which are designed as clamping spring washers. A recess 31a is provided in the curved section 26a, which forms a material weakening in this area for adjusting the desired spring core line. The function of these spring clips 21a corresponds to that of the spring clips 21 as described above.

[0045] An alternative design of the spring clip is shown in the Figures 13 and 14The spring clip 21b also has a substantially U-shaped central portion with a web 24b and legs 25b that are bent at right angles from the web. The leg ends are bent at right angles to sections 26b, which in turn are bent at 90° to short sections 27b parallel to the legs, which in turn are bent at 90° and have end sections 28b directed toward the legs 25b, which are designed as clamping spring washers. The spring clips 21b have substantially almost right-angled bends, but comparatively large-area recesses 31b that extend over the entire length of the section 26b as well as over parts of the leg 25b and the section 27b.

[0046] Another design variant of a spring clip is based on the Figures 15 and 16The spring clip 21c also has a U-shaped central section with a web 24c and two legs 25c that slope slightly inward from there. The leg ends are bent by more than 180° in sections 26c such that the adjoining sections 27c extend perpendicular to the web 24c, with the end sections 28c in turn being bent outward by 90° and configured there as clamping spring washers. This design also features recesses 31c, specifically in the area of ​​the sections 26c.

[0047] All of the spring clips described above have the function described at the beginning, are integrated laterally into the intermediate housing 11a and, together with this, are placed onto the clamping pin 17 of the housing 1 and are thus permanently clamped, whereby the contact pressure during clamping pre-tensions the spring as a whole in order to exert spring force with its web 24-24c onto the circuit board section 8 and thus the ultrasonic transducer 10 located underneath. List of reference symbols

[0048] 1Housing 2Channel 3Input connector 4Output connector 5Board 6Display 7Batteries 8Board sections 9Arms 10Ultrasonic transducer 11Intermediate housing in the Figures 1 and 3 to 5 11aIntermediate housing in the Figures 2 , 7 and 812Recess in the intermediate housing 13Transparent section in the cover 14Cover 15Coil springs 16Clamping spring washers 17Clamping pins 18Cavities in the intermediate housing 19Collar on the intermediate housing 11a 20Tongs of the intermediate housing 11a 21Spring clip 21a,b,cSpring clip 22Recesses in the tongues 23Ring sections 24Web of the U-shaped clip 24a,b,cWeb 25Legs of the U-shaped clip 25a,b,cLegs 26Clip sections 26a,b,cSections 27Clip sections 27b,cSections 28End sections of the clip 28a,b,cEnd sections 29Annular part 30Segment sections 31Recesses 31a,b,cRecesses 32Antenna

Claims

1. An ultrasound flow measuring device with a housing (1), with a channel (2) formed integrally with the housing (2) for the passage of a fluid, the flow of which is to be measured, with at least one ultrasound transducer (10), which is arranged within the housing (1) on a wall delimiting the channel (2), characterized in that the at least one ultrasound transducer (10) is fixed within the housing (1) by means of at least one non-releasable snap and / or clamping connection (16, 17).

2. The ultrasound flow measuring device according to claim 1, characterized in that at least one clamping pin pair (17) is provided within the housing (1) for each ultrasound transducer (10) and that each ultrasound transducer (10) is fixed with clamping spring disks (16, 28, 28a-c) on the clamping pin pair (17).

3. The ultrasound flow measuring device according to one of the preceding claims, characterized in that a printed circuit board (5) with electrical and electronic components (6, 7) is arranged within the housing (1), that a cover (14) closing the housing (1) and an intermediate housing (11, 11a) arranged in the housing (1) between housing cover (14) and printed circuit board (5) is provided, said intermediate housing is fastened within the housing (1) by means of a clamping spring and holds spring means (15, 21) in a positive manner for applying a force to the at least one ultrasound transducer (10) and clamping spring disks (16, 28, 28a-c)4. The ultrasound flow measuring device according to claim 3, characterized in that the intermediate housing (11, 11a) is made of plastic and the spring means (15, 21) and the clamping spring disks (16, 28, 28a-c) consist of metal and are incorporated in a positive manner into the intermediate housing (11, 11a) or between housing (1) and intermediate housing (11, 11a).

5. The ultrasound flow measuring device according to claim 3 or 4, characterized in that the spring means (15) for applying a force to an ultrasound transducer (10) are formed by at least one helical spring (15) arranged on the intermediate housing side.

6. The ultrasound flow measuring device according to claim 3 or 4, characterized in that the spring means (21) for applying a force to an ultrasound transducer (10) as spring clips (21) and the clamping spring disks as end sections (28, 28a-c) of the spring clip (21) are formed integrally.

7. The ultrasound flow measuring device according to claim 6, characterized in that the spring clip (21) is formed by a spring plate (21).

8. The ultrasound flow measuring device according to claim 7, characterized in that the spring plate (21) forms two clamping spring disks in its end sections (28, 28a-c) for fastening to a housing-side clamping pin pair (17).

9. The ultrasound flow measuring device according to claim 8, characterized in that at least one tongue pair (20) is provided on the intermediate housing (11a), which tongue pair receives the spring clip (21) in a positive manner and through which the clamping pin pair (17) passes.

10. The ultrasound flow measuring device according to one of claims 6 to 9, characterized in that the spring clip (21b) has a central section, which is U-shaped in the side view, the web (24b) of which acts on the ultrasound transducer (10) or the printed circuit board section (8), on which the ultrasound transducer (10) is arranged, wherein free leg ends (26b) of the U-shaped central section are bent transversely outwards, then each merge into a section (27b) running parallel to the leg and are bent towards the leg (25b) in a free end section (28b), wherein each end section (28b) is formed as clamping spring disk.

11. The ultrasound flow measuring device according to one of claims 6 to 9, characterized in that the spring clip (21a, 21c) has a central section, which is U-shaped in the side view, the web (24a, 24c) of which acts on the ultrasound transducer (10) or on the printed circuit board section (8), on which the ultrasound transducer (10) is arranged, wherein free leg ends (26a, 26c) of the U-shaped central section are arcuately bent outwards by 180 degrees and, on the end side, have web-parallel end sections (28a, 28c), which are formed as clamping spring disks.

12. The ultrasound flow measuring device according to one of claims 6 to 9, characterized in that the spring clip (21) has a central section, which is U-shaped in the side view, the web (24) of which acts on the ultrasound transducer (10) or on the printed circuit board section (8), on which the ultrasound transducer (10) is arranged, wherein the legs (25) of the U-shaped central section taper obliquely inwards and the free legs ends (26) of the U-shaped central section are bent obliquely outwards and upwards, then each merge into a section (27) running parallel to the leg and are bent towards the leg (26) with a free end section (28), wherein each end section (28) is formed as clamping spring disk.

13. The ultrasound flow measuring device according to one of claims 6 to 12, characterized in that the spring clip (21) has recesses (31) in sections.

14. The ultrasound flow measuring device according to one of the preceding claims, characterized in that an ultrasound transducer (10) is arranged on a printed circuit board section (8) of a printed circuit board (5), which is arranged in an elastically movable manner with respect to the remaining printed circuit board (5), and that the ultrasound transducer (10) is connected to the printed circuit board section (8) by means of a permanently elastic electrically conductive adhesive.

15. The ultrasound flow measuring device according to one of claims 6 to 14, characterized in that the ultrasound transducer (10) is contacted at two opposite front sides, is electrically conductively connected to a printed circuit board (5) or a printed circuit board section (8) at a front side and to the printed circuit board (5) via the spring clip (21) with the other front side.

16. The ultrasound flow measuring device according to one of claims 3 to 15, characterized by one or several of the following features: - the intermediate housing (11) receives water-absorbing means, - the intermediate housing (11) receives an antenna, - the housing (1) is formed in a pot-shaped manner, - the channel (2) is integrated into the housing (1) on the bottom side, - the housing (1) is formed as plastic injection molded part, - the cover (14) is tightly welded to the housing (1), - the printed circuit board (5) is provided with a display (6) on its side facing the intermediate housing (11), - the intermediate housing (11) has a recess (12) aligned with the display (6), - the cover (14) is formed in a transparent manner so as to be aligned with the display (6) at least in the region of the recess (12), and - two ultrasound transducers (10) are provided on diametrically opposite sections (8) of the printed circuit board (5) and a force is applied to them by means of the spring means (15, 21).