Flow meter, sealed cavity and mounting method

Abstract

The invention relates to a flow meter (10) comprising a housing (11) equipped with a pipe (20) and means (12, 13) for measuring the flow rate of fluid circulating in this pipe (20). The flow meter (10) incorporates electronics (14) within the internal space of the housing, which is held in a sealed cavity (30) formed by resin (114, 115). The invention also relates to the method of manufacturing the flow meter (10). [Figure for the abstract: Fig. 1]

Description

Title of the invention: Flow meter, sealed cavity and mounting method. Technical field

[0001] The invention relates to a flow meter and its mounting method. The flow meter according to the invention makes it possible to measure the flow rate of a fluid such as water. In particular, the flow meter according to the invention comprises a sealed cavity including insulating resin walls. Previous technique

[0002] The evolution of flow meter technologies and in particular of water meters has led to the introduction of ultrasonic measurement methods which involve embedding electronics in flow meters.

[0003] However, this type of flow meter is generally installed in a humid environment. The walls of a flow meter housing exhibit significant hydraulic diffusivity. Indeed, if the humidity inside the housing is low, the moisture and / or water present in the flow meter's surrounding environment will inevitably seep into the housing. This phenomenon eventually leads to problems that impair the proper functioning of the flow meter. In fact, humidity can act as a dielectric across the terminals of a battery and cause short circuits; moreover, some quartz crystals are very sensitive to humidity, which can lead to problems with their behavior and result in metrological errors.

[0004] Currently, there are two techniques for protecting the electronics of a flow meter from the accumulation of moisture in the internal space of the housing.

[0005] The first technique consists of creating a void, known as a dry cavity, within the internal space of the housing. To achieve this, the housing comprises walls between 5 and 10 mm thick, generally made of glass or, more broadly, a mineral material. However, manufacturers avoid the exclusive use of glass or a mineral material because it results in a significant increase in production costs. Thus, at least one of the walls is generally made of glass, while the others are made of plastic. The glass walls make the mechanical design of the housing complex and expensive, particularly with regard to creating a watertight seal with the housing, which is generally made of plastic. Indeed, this type of housing incorporates sealing elements between the various components that make up the housing, which also increases the complexity and cost of its design.

[0006] A second technique consists of flooding the internal space of the casing using a A resin that exhibits sealing properties after solidifying within the internal space. This technique advantageously allows for the design of a housing with a simplified structure and assembly while ensuring a seal between the various components. It is thus possible to eliminate the gaskets and sealing systems traditionally used to ensure watertightness between the housing parts.

[0007] This technique prevents condensation in areas containing air around all cold spots with higher heat capacity. However, when the resin becomes saturated with water, malfunctions in the electronic components due to humidity occur and compromise the reliability of the flow meter. In the case of a polyurethane-type resin, for example, commercial resins available from manufacturers such as SIKA® or HENKEL®, this type of malfunction is observed, depending on the case, after 2000 to 4000 hours of accelerated aging tests.

[0008] The invention aims to overcome all of these drawbacks. Description of the invention

[0009] The invention aims to improve the sealing of a flow meter which is intended to be installed in a humid environment.

[0010] The invention aims in particular to protect the electronic components of a flow meter from the intrusion of moisture or water.

[0011] The invention also aims to simplify the mechanical design of the flow meter housing.

[0012] To this end, the invention relates to a flow meter comprising: - a case which includes partitions delimiting an internal space of the case; - a pipe mounted through the internal space of the casing, the pipe The system is configured to be connected to a network carrying a fluid flow; - at least one cohesive filling resin that partially fills the internal space and coats the pipe; - ultrasonic means for measuring the flow rate of a fluid flowing through the pipe, the measuring means being coupled to the pipe; - a sealed cavity comprising: • a first sealing wall formed by the filling resin in a cohesive state, • a second sealing wall opposite the first sealing wall; the second sealing wall comprises a layer of the encapsulating resin in a cohesive state, • a peripheral sealing belt comprising a cohesive encapsulating resin and surrounding electronic means; the peripheral belt hermetically seals the first sealing wall and the second sealing wall to form the sealed cavity; and the electronic means of the flowmeter being disposed in the sealed cavity and connected to the ultrasonic measuring means through the sealed cavity.

[0013] The use of a cohesive resin to create a sealed cavity allows for the isolation of the electronics, simplifying the mechanical design of the housing. Indeed, according to the invention, the sealed resin cavity, without embedding the flow meter's electronics in the resin, reduces the number of components in the housing. For example, the resin eliminates the need for seals between the different housing components. Furthermore, using cohesive resin walls to form the sealed cavity reduces the housing's mass and manufacturing costs. In this document, the cohesive state of the resin refers to a resin that remains stable under the action of internal or external forces, as opposed to the fluid state or the liquid state of the resin in which it is poured.A resin in a cohesive state can be solid or elastic as long as it forms a coherent volume of matter that does not flow or disintegrate under the effect of external forces such as gravity.

[0014] In some embodiments, the peripheral belt comprises a double wall that laterally encircles the sealed cavity, the double wall forming a peripheral cavity in the internal space which is filled with the encapsulating resin in a cohesive state. The double wall constitutes a receptacle that surrounds the electronics of the housing, into which the encapsulating resin can be poured to provide a sealing belt. It is thus possible to control the flow of the resin during the manufacturing of the flow meter.

[0015] In some embodiments, the encapsulating resin of the peripheral belt adheres to the filling resin. The adhesion of the two resins creates a seal and thus forms the sealed cavity. According to these embodiments, the filling resin defines the lower boundary of the peripheral belt. This allows the sealed cavity to be closed without the need for an additional sealing element such as a gasket.

[0016] In some embodiments, the second sealing wall comprises a closure platform which has at least one opening communicating with the peripheral belt, the resin layer extending over the outer face of the closure platform, the resin of the peripheral belt and the resin layer being bonded at least through this opening. The communicating opening This allows the resin to be poured onto the sealing platform, forming in a single step a sealed body that includes the second sealing wall extending over the sealing platform and the sealing belt extending into the internal space of the housing and surrounding the flow meter electronics. This feature also helps reduce the number of parts used in the housing design.

[0017] In some embodiments, the closure platform includes a peripheral rim coupled to the partitions of the housing. The peripheral rim is connected to the platform via a predetermined number of spacers, with an opening communicating with the peripheral rim being located between two consecutive spacers. The peripheral rim allows control of the encapsulation resin flow, while the spacers provide communicating openings that form passages allowing the resin to flow and form a single, sealed body.

[0018] In some embodiments, the closure platform includes a peripheral skirt configured to fit into the internal space of the housing so as to form the peripheral belt by cooperating with the partitions of the housing. The skirt extends parallel to the peripheral partition and forms the double wall that constitutes the peripheral cavity.

[0019] In embodiments, each spacer extends between the peripheral rim and the peripheral skirt, the opening then communicating with the peripheral belt which extends into the internal space of the housing.

[0020] In some embodiments, the housing includes a peripheral shoulder extending onto the inner face of the partitions that define the internal space of the housing, the filling resin extending into the internal space up to the level of the peripheral shoulder. The shoulder allows control of the flow of the filling resin during the manufacturing process.

[0021] In embodiments, the housing includes a compartment receiving at least part of a battery which powers the electronic means and the ultrasonic measuring means, the compartment being isolated from the pipe by the filling resin.

[0022] In some embodiments, the sealed cavity includes a moisture absorber. The moisture absorber captures condensation that may form inside the sealed cavity, for example, due to temperature changes in the environment surrounding the flow meter.

[0023] In some embodiments, the housing comprises: - a base piece comprising a case back and walls that integrate with the case partitions, - an intermediate piece that fits into the base piece, the intermediate piece The intermediate section carries the piping and includes an assembly frame that fits onto the walls of the base piece to define a peripheral partition of the housing, and - a closure platform that includes: • a peripheral rim configured to fit onto the assembly frame of the intermediate part, and • a part that extends into the internal space and cooperates with the peripheral partition to form the peripheral belt.

[0024] In some embodiments, the housing includes a support piece that is interposed between the filling resin and the electronic means. The support piece allows the electronic means to be held in a predetermined position within the sealed cavity.

[0025] In embodiments, the encapsulation resin has, in the cohesive state, a Shore D hardness of less than 50. In particular, the Shore D hardness may be between 40 and 50.

[0026] In embodiments, the filling resin has, in the cohesive state, a Shore D hardness greater than 60, preferably greater than 70, and even more preferably between 80 and 90. The Shore D hardness of the filling resin makes it possible to rigidify the casing in the vicinity of the pipe.

[0027] In embodiments, the filling resin is chosen from the following resins: polyurethane resins, polyurethane resin derivatives, polyester resins, polyester resin derivatives, silicone resins, silicone resin derivatives.

[0028] In embodiments, the encapsulation resin is chosen from the following resins: polyurethane resins, polyurethane resin derivatives, silicone resins, silicone resin derivatives.

[0029] The invention also relates to a method for manufacturing a conforming flowmeter of the invention. The method is characterized in that it comprises at least the following steps: - to couple the electronic means to the measuring means and to the flowmeter housing, the electronic means being arranged in an upper compartment of the internal space of the housing, - closing the case with a partition, said partition being constituted by a closing platform, the fitting of the closing platform onto the case provides a partitioned peripheral belt which surrounds the electronic means, the peripheral belt communicating with a lower compartment of the case, - pour an encapsulation resin, in a fluid state, at least onto the platform

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] of closure and in the peripheral belt of the case, and - to form at least one sealing wall on the closing platform and one sealing wall in the peripheral belt so as to produce a sealed cavity around the electronic means, said sealing walls being formed by setting of the encapsulation resin, the setting of the encapsulation resin corresponding to the passage of the encapsulation resin from the fluid state to the cohesive state. The process offers the same advantages as the flow meter; it allows for the formation of a sealed cavity by pouring resin in a controlled manner into the flow meter housing. In some embodiments, the manufacturing process includes, before the case closing step, the following steps: - to pour a filling resin, in a fluid state, into the lower compartment of the internal space of the housing up to a defined level, the filling resin coating the pipe equipped with the measuring means, - to form a first sealing wall of the sealing cavity which constitutes the bottom of the peripheral belt, the first wall being formed by setting the filling resin, the setting of the resin corresponding to the passage of the filling resin from the fluid state to the cohesive state. In some embodiments, before setting, the encapsulating resin is less viscous than the filling resin. The encapsulating resin can thus flow through small openings to fill the peripheral belt. In some embodiments, the encapsulation resin is poured onto the closure platform in a fluid state and flows, through at least one opening provided on the closure platform, into the peripheral belt, the sealing wall - forming the resin layer of the closure platform - and the peripheral sealing belt being formed by the same body of encapsulation resin. In some embodiments, the setting time of the encapsulating resin is longer than the setting time of the filling resin. In some embodiments, the setting time of the encapsulating resin is less than or greater than 120 minutes, preferably greater than 180 minutes, and preferably greater than 240 minutes. The long setting time of the encapsulating resin allows it to flow into small spaces before hardening and thus form a homogeneous sealing wall, particularly in the peripheral ring. In some embodiments, the setting time of the filling resin is 60 minutes, preferably less than 30 minutes and even more preferably less than 10 minutes. In some embodiments, the setting of the encapsulation resin is carried out at room temperature. In other embodiments, the setting time of the encapsulation resin can be accelerated by heating the housing.

[0038] In some embodiments, the filling resin sets at room temperature. In other embodiments, the resin setting time can be accelerated by heating the housing. Brief description of the drawings

[0039] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0040] [Fig-1] is a perspective representation of an embodiment of a conforming flowmeter of the invention.

[0041] [Fig.2] is a representation of an exploded view of the flow meter of [Fig. 1].

[0042] [Fig.3] is a perspective representation of the flow meter of [Fig.1] in which The finishing cover has been removed.

[0043] [Fig.4] is a perspective representation of an embodiment of a die bitmeter conforming to an embodiment of the invention, in which neither the cover, nor an intermediate part of the housing nor the piping are represented in order to show from the outside the elements constituting the sealed cavity of the flowmeter.

[0044] [Fig.5] is a representation of a longitudinal section of the flow meter housing of the [Fig.3].

[0045] [Fig.6] is a representation of a cross-section of the flow meter housing of the [Fig. 1]

[0046] [Fig.7] is a perspective representation of the housing closure platform conforming to an embodiment of the flow meter of the invention.

[0047] [Fig.8] is a representation of a cross-section of the closing platform of the [Fig.7]

[0048] [Fig.9] is a perspective representation of a base piece of the case which is conforming to an embodiment of the flow meter of the invention.

[0049] [Fig. 10] is a perspective representation of an intermediate part of the housing which conforms to an embodiment of the flow meter of the invention.

[0050] [Fig. 11] is a schematic representation of a method for manufacturing a conforming flowmeter of the invention in the form of a logic diagram. Description of the implementation methods

[0051] With reference to Figures 1 to 10, the present invention relates to a flow meter 10 for measuring the flow of fluid circulating in a pipe. According to one embodiment of the invention, the flow meter 10 can be a water meter for measuring the flow rate of a water pipe within a domestic water network, in- industrial or other.

[0052] As illustrated in Figures 1 to 6, the flow meter 10 comprises a housing 11 which includes an internal space. In particular, the housing 11 includes partitions 110, 111, 112 which delimit an internal space of the housing 11. Two partitions 110, 112 are opposed to each other, and a peripheral partition 111 forms the junction between the partitions 110 and 112. As illustrated in [Fig. 3] and according to the spatial orientation of the housing 11 in the diagram of [Fig. 3], the partition 110 delimits the internal space superiorly, the partition 112 delimits the housing 11 inferiorly, and the peripheral partition defines the internal space of the housing 11 laterally.

[0053] As can be seen in particular in [Fig. 5], the flow meter 10 includes a pipe 20 mounted through the internal space of the housing 11. The pipe 20 is configured to be connected to a network conveying a fluid flow, such as a hydraulic network. To this end, the pipe 20 has two ends 21, 22, which are respectively equipped with a fitting. In this example, the fitting has an external thread for connection to a network conveying a fluid flow.

[0054] As illustrated in Figures 4 to 6, the flow meter 10 comprises at least one cohesive filling resin 114 that partially fills the internal space of the housing 11 and coats the pipe 20. According to one embodiment of the invention, the filling resin 114 can be selected from the following resins: epoxy resin, polyurethane resin, silicone resin, or their derivatives. By way of example, commercial polyurethane resins are available from manufacturers such as SIKA® or HENKEL® and are sold as two components to be mixed: a polymerizing agent, also called a hardener, and a polyurethane precursor. The polymerizing agent may be an isocyanate compound and the polyurethane precursor a polyol compound. The resin may also consist of a thermoplastic polymer such as polyurethane, epoxy, or silicone in a fluid or solvated state that becomes cohesive upon drying by evaporation of the solvent.

[0055] As can be seen in [Fig. 2], the flow meter 10 comprises ultrasonic means 12, 13 for measuring the flow rate of a fluid flowing through the pipe 20. The measuring means 12, 13 are coupled to the pipe 20. According to the embodiment illustrated in [Fig. 2], the measuring means 12, 13 incorporate two ultrasonic transducers 12, 13 arranged coaxially on either side of the pipe 20. Preferably, the axis on which the ultrasonic transducers 12, 13 are arranged is oriented at an angle less than or greater than 90° with respect to the longitudinal axis of the pipe 20. In an alternative embodiment, a single transducer cooperating with at least one mirror allows the fluid flow in the pipe 20 to be measured.

[0056] As can be seen in Figures 5 and 6, the flowmeter 10 includes a sealed cavity 30, which can also be called a "dry cavity." The sealed cavity 30 provides storage for the electronic means 14 of the flowmeter 10. The electronic means 14 may include an electronic board, a microprocessor, memory, an electronic clock, a display screen, and other electronic components necessary for the operation of the flowmeter 10. In the example shown in Figures 5 and 6, the sealed cavity 30 is schematically represented by a dashed outline.

[0057] In the example illustrated in Figures 5 and 6, the sealed cavity 30 comprises a first sealing wall 31 formed by the filling resin 114 which encapsulates the pipe 20. The filling resin 114, in a cohesive state, fills a lower compartment of the housing 11 in which the pipe 20 is mounted through-hole. According to this configuration, the upper surface of the filling resin 114 delimits the lower compartment from the upper compartment of the housing 11. The upper surface of the filling resin also constitutes the first sealing wall 31 of the sealed cavity 30.

[0058] The sealed cavity 30 has a second sealing wall 32 opposite the first sealing wall 31. The second sealing wall 32 comprises a layer 320 of encapsulating resin 115 in a cohesive state. The encapsulating resin 115 may be a dielectric resin. The encapsulating resin 115 may include a resin such as polyurethane resins, silicone resins, or their derivatives. Furthermore, the encapsulating resin 115 has physicochemical properties that distinguish it from the filling resin 114.

[0059] According to one embodiment, the encapsulation resin 115 can be semi-rigid in its cohesive state and may have a Shore D hardness of less than 50. In particular, the Shore D hardness may be between 40 and 50. Exposure of the housing 11 to high or low ambient temperatures results in differential expansion between the encapsulation resin 115 and the electronic components. This differential expansion generates stresses on the electronic components, which can degrade. The semi-rigid nature of the encapsulation resin 115 in its cohesive state helps to reduce these phenomena. In comparison, the filler resin 114 is considered rigid in its cohesive state. Indeed, the filler resin 114 can have a Shore D hardness greater than 60 in its cohesive state, preferably greater than 70, and even more preferably between 80 and 90.This rigidity helps to reinforce the mechanical resistance of the housing 11 around the pipe 20.

[0060] According to another embodiment, the encapsulation resin 115 has a lower viscosity in the fluid state than the filling resin 114. This low viscosity gives the encapsulation resin 115 greater fluidity which allows it to flow into more restricted spaces than the filling resin 114.

[0061] According to another embodiment, the encapsulating resin 115 has a lower curing rate than the curing rate of the filling resin 114, thus transitioning more slowly from a fluid / viscous to a cohesive state. For example, the curing rate of the encapsulating resin 115 may be greater than 120 minutes, preferably greater than 180 minutes, and even more preferably greater than 240 minutes. In comparison, the filling resin 114 has a curing rate of less than 60 minutes, preferably less than 30 minutes, and even more preferably less than 10 minutes.

[0062] This slower curing speed allows the encapsulation resin 115 to flow into restricted spaces and create a seal between several parts of the housing 11 without using additional sealing elements such as gaskets.

[0063] As mentioned previously, the manufacturers “SIKA ®” or “HENKEL ®” offer resins, for example, of the polyurethane type which have the characteristics necessary to be used as encapsulation resin 115 conforming to the invention.

[0064] As illustrated in Figures 4 to 6, the sealed cavity 30 also includes a peripheral sealing belt 33 comprising an encapsulation resin 115, in a cohesive state, which surrounds the electronic means 14. The peripheral belt 33 forms a sealed link between the first sealing wall 31 and the resin layer 320 of the second sealing wall 32.

[0065] As illustrated in Figures 2 to 6, the peripheral belt 33 and the second sealing wall 32 form a single-piece sealing body which is integrated into the structure of the housing 11 of the flowmeter 10. In particular, in an embodiment illustrated in Figures 3 and 4, the resin layer 320 extends outside the housing 11 while the resin 115 of the peripheral belt 33 extends inside the housing 11.

[0066] In particular, in one embodiment, the peripheral belt 33 comprises a double wall that laterally encircles the sealed cavity 30. In this example, the double wall forms a peripheral cavity 330 in the internal space, which is filled with the encapsulating resin 115. The encapsulating resin 115 of the peripheral belt 33 is preferably poured into contact with the filling resin 114, which is already in a cohesive state. Consequently, the encapsulating resin 115 sets in the peripheral cavity 330 while in contact with the filling resin 114 and adheres to the filling resin 114, thus forming a sealed junction between the two resins 114 and 115.The setting of the encapsulation resin 115 is independent of its contact with the filling resin 114; it is linked to the polymerization reaction between precursors of the encapsulation resin 115 and / or to the evaporation of the solvent which solvated the encapsulation resin 115. The filling resin 114. constitutes a wall of the peripheral cavity 330. In this case, the filling resin 114 delimits the peripheral cavity 330 below while forming a watertight bond with the encapsulation resin 115.

[0067] According to one embodiment, the second sealing wall 32 comprises a closing platform 110. The closing platform 110 is visible in the exploded view of [Fig.2] and shown in isolation in Figures 7 and 8. The closing platform 110 constitutes a partition which delimits the internal space of the housing 11.

[0068] The closing platform 110 closes the housing 11. For this purpose, the closing platform 110 is opposite the upper surface of the filling resin 114. According to a particular embodiment, the closing platform 110 is parallel to the upper surface of the filling resin 114.

[0069] As can be seen in particular in figures 3 and 4, the resin layer 320 extends over the external face of the closure platform 110. Advantageously, the closure platform 110 has at least one opening 1101 communicating with the peripheral belt 33. The resin layer 320 and the resin 115 of the peripheral belt 33 are joined at least through this opening 1101.

[0070] According to the embodiment illustrated in figures 7 and 8, the closing platform 110 comprises a peripheral rim 1102 and a platform 1103. The peripheral rim 1102 extends perpendicularly to the platform 1103. The peripheral rim 1102 is also salient on either side of the plane in which the platform 1103 extends.

[0071] As is particularly evident in [Fig. 8], the peripheral rim 1102 is offset from the platform 1103 and connected to it by means of a specific number of spacers 1104. Consequently, an opening 1101 communicating with the peripheral belt 33 is located between two consecutive spacers 1104. The closing platform 110 thus comprises a plurality of openings 1101, each communicating with the peripheral belt 33.

[0072] In particular, each opening 1101 provides a passage that allows the resin 115 to be poured onto the tray 1103 and to flow into the peripheral cavity 330 through one or more openings 1101 during the manufacture of the flowmeter 10. The use of a less viscous resin and / or one with a longer setting time to constitute the encapsulating resin 115 allows the resin to flow, in particular, through the plurality of openings 1101 to reach the peripheral cavity 330. As a result, the encapsulating resin 115 filling the peripheral ring 33 forms a single-piece, sealed body with the resin layer 320. This sealed body cooperates with the outer surface of the filling resin 114 to form the sealed cavity 30.

[0073] As illustrated in particular in Figures 5 to 8, the closing platform 110 comprises a peripheral skirt 1105 which is configured to fit into the space internal of the housing 11. In this example, the peripheral skirt 1105 protrudes from the inner face of the closure platform 110. As can be seen in [Fig. 8], the peripheral rim 1102 extends at least partially parallel to the peripheral skirt 1105. In particular, over a portion of the height of the peripheral skirt 1105, the peripheral rim 1102 overlaps the wall of the peripheral skirt 1105. The spacers 1104 thus extend between the peripheral skirt 1105 and the peripheral rim 1102, at least partially over the overlapping portion between the peripheral rim 1102 and the peripheral skirt 1105.

[0074] The peripheral skirt 1105 has dimensions that are smaller than the cross-section of the internal space so as to fit into the partitions 111 of the housing 11. The peripheral skirt 1105 thus cooperates with the partitions 111 of the housing 11 so as to form the peripheral belt 33. More precisely, the double wall that delimits the peripheral cavity 330 is formed by the cooperation between the peripheral skirt 1105 and the peripheral partition 111.

[0075] As illustrated in Figures 5 and 6, while the peripheral skirt 1105 is fitted into the internal space of the housing 11, the peripheral rim 1102 fits onto a free edge 1110 of the peripheral partition 111 of the housing 11. In the embodiment illustrated in Figures 5 and 6, the free edge 1110 of the peripheral partition has a configuration complementary to the free edge 1106 of the peripheral rim 1105, which facilitates their fitting. Here, the free edge 1110 has a shoulder complementary to the shoulder formed on the edge 1106 of the peripheral rim 1105. This complementarity facilitates assembly and increases the mechanical strength of the housing 11.

[0076] In this example, the closing platform 110 includes at least one transparent window 1107 formed on the surface of the plate 1103. The window 1107 allows information to be read on a display screen located in the sealed cavity 30 opposite this window 1107. In this example, the closing platform 110 includes two transparent windows 107. Each window corresponds, here, to a transparent bead that protrudes from the plate 1103 of the closing platform 110. According to another embodiment, the closing platform 110 may include a deformable button 1108 that can actuate a selection button connected to the electronic means 14.

[0077] According to one embodiment, the electronic means 14 are attached to at least one structural element of the housing 11. According to another embodiment, the electronic means 14 are attached to the inner face of the closure platform 110 in order to be held fixed within the sealed cavity 30.

[0078] Furthermore, the measuring means 12, 13 include connectors 130 which are configured to be connected to the electronic means 14 through the cavity watertight, see in particular [Fig.2] and 6. For these purposes, the connectors 130 are dimensioned so as to pass through the thickness of the filling resin 114 and to protrude into the watertight cavity 30. The connectors 130 thus connect to the electronic means 14 while maintaining the watertightness of the sealed cavity 30.

[0079] According to an unillustrated embodiment of the invention, the sealed cavity 30 includes a moisture absorber. The moisture absorber may be a desiccant. The moisture absorber absorbs moisture that would otherwise pass into the sealed cavity 30 and / or condensation of moisture contained in the air during the formation of the sealed cavity 30. This extends the service life of the flow meter 10.

[0080] According to an embodiment illustrated in [Fig. 5], the housing 11 has an internal peripheral shoulder 113 extending onto the inner face of the peripheral partition 111. The filling resin 114 extends into the internal space up to the level of the peripheral shoulder 113. The internal peripheral shoulder 113 allows, during the manufacture of the flowmeter 10, precise control of the filling level of the filling resin 114 in the internal space of the housing 11. In addition, the shoulder 113 also serves to delimit the lower compartment from the upper compartment of the housing 11.

[0081] According to one embodiment, the housing 11 comprises a compartment 116 extending from a partition 112 of the housing 11 to the sealed cavity 30. In particular, the compartment 116 extends from the partition 112 defining the bottom of the housing 110. The compartment 116 receives at least part of a battery 15 that powers the electronic means 14 and the ultrasonic measuring means 12, 13. The battery 15 may comprise one or more accumulators. Preferably, the compartment 116 receives the entire battery. The compartment 116 is advantageously insulated from the pipe 20 by the filling resin 114. Indeed, the compartment 116 extends from the bottom of the housing 11 located in the lower compartment to the sealed cavity 30. Figures 6 and 9 illustrate this arrangement in particular.The housing 116 is delimited, on the one hand, by the peripheral partition 111 of the housing 11, and on the other hand, by an internal partition 1160 which connects two sides of the peripheral partition 111 (see in particular Figures 2 and 9). The housing 116 includes a cover 1161 which has openings to allow the passage of the electrical connector between the battery 15 and the electronic means 14. The cover 1161 ensures the sealing of the housing 116 and prevents any dielectric phenomenon at the terminals of the battery 15. In addition, the battery 15 may also have a waterproof coating, for example, a polyethylene film or a polyvinyl chloride film.

[0082] In an embodiment illustrated in particular in figures 2, 3 and 9, the housing 11 includes a base piece 16 which integrates a base 160 of the housing 11 and walls 161. The walls 161 are integrated into the peripheral partition 111 which delimits the internal space of the housing 11. In particular, as can be seen in [Fig.6], the bottom piece 16 delimits at least in part the first compartment of the internal space into which the filling resin 114 is poured.

[0083] As illustrated in Figures 2, 4, and 9, the base piece 16 may have two cutouts 162 arranged coaxially with respect to each other. The two cutouts 162 are formed respectively in two opposite walls 161. As illustrated in Figures 2 and 9, the axis CC along which the two cutouts 162 are formed is perpendicular to the longitudinal axis of the housing 116.

[0084] The two cutouts 162 allow the pipe 20 to be fitted into the base piece 16 and to receive in particular the ends 21, 22 of the pipe 20.

[0085] According to an embodiment illustrated in Figures 2 and 10, the housing 11 comprises an intermediate piece 17 which fits into the base piece 16. In this example, the intermediate piece 17 carries the pipe 20 and includes an assembly frame 170 which fits onto the walls 161 of the base piece 16 so as to define the peripheral partition 111 of the housing 11. As can be seen in particular in [Fig. 10], the intermediate piece includes two tabs 171 which extend from the assembly frame 170. The tabs 171 are opposite each other and allow the pipe 20 to be assembled to the intermediate piece 17. For example, the intermediate piece 17 can be made by injection molding and thus produced in one piece.For these purposes, it is possible to use a carbon fiber-reinforced polymer which makes it possible to provide a pipe 20 which exhibits resistance to a fluid pressure, circulating in the pipe 20, which is greater than 75 bars.

[0086] Advantageously, the housing 11 includes means for fitting the intermediate piece 17 onto the base piece 16. As is particularly visible in [Fig. 9], the fitting means include an assembly edge 163 and an angle bracket 164. The angle bracket 164 extends parallel to the assembly edge 163. In this example, the assembly edge 163 is projecting from the angle bracket 164.

[0087] As illustrated in [Fig.1], the assembly frame 170 and each ear 171 of the intermediate piece 17 fit onto the angle 164 of the base piece 16.

[0088] In an embodiment illustrated in [Fig. 9], the interlocking means may include receiving lugs 165 of the pipe 20. In this example, the receiving lugs 165 protrude internally from the bottom 16 of the housing 11. [Fig. 10] shows a particular arrangement in which the lugs 165 are arranged in pairs along two opposite axes. Furthermore, the lugs 165 on a first axis are staggered with respect to the lugs 165 located on the second axis.

[0089] In an embodiment illustrated in [Fig. 10], the intermediate piece 17 can also integrate at least one receiving housing 172 of the measuring means 12, 13. The receiving housing 172 is located on a wall of the pipe 20. According to the embodiment which includes two ultrasonic transducers 12, 13, the intermediate piece 17 includes as many receiving housings 172 as ultrasonic transducers 12, 13.

[0090] The intermediate piece 17 can be equipped with retaining elements for the electronic means 14. The retaining elements allow the electronic means 14 to be held in a fixed position within the sealed cavity 30.

[0091] According to the embodiment illustrated in Figures 8 and 10, the retaining members comprise two pads 173 extending longitudinally from the conduit 20 to the closing platform 110. Each pad 173 may include a central hole 1730 for attaching a mechanical connector 141, such as a screw, as illustrated in particular in [Fig. 2]. Furthermore, each pad 173 may include support ribs 1731. The pads 173 and the support ribs 1731 allow the electronic means 14 to be held, via the electronic board, approximately in the center of the sealed cavity 30. The pads 173 control, in particular, the vertical position of the electronic means 14 within the internal space of the housing 11.

[0092] As illustrated in Figures 8 and 10, the retaining members may also include at least one stop element 174 which is disposed against the walls of the assembly frame 170. In this example, the retaining members include two stop elements 174 which are arranged opposite each other. The gap between the two stop elements 174 is less than the lower dimensions of the peripheral skirt 1105. The peripheral skirt 1105 thus fits onto the two stop elements 174. As illustrated in [Fig. 5], the two stop elements 174 are placed in contact with the underside of the plate 1103 of the closing platform 110. The stop elements 174 thus ensure assembly accuracy.

[0093] In addition, the stop elements 174 also allow the electronic means 14 to be held, through the electronic board, approximately in the center of the sealed cavity 30. The stop elements 174 allow the position of the electronic means 14 to be controlled laterally.

[0094] According to one embodiment, the intermediate piece 17 carries the internal peripheral shoulder 113 of the housing 11. In the example of [Fig.5], this shoulder 113 may be salient from the internal space.

[0095] In the example of [Fig. 4], the intermediate piece 17 is not shown; this allows visualization of the one-piece sealed body formed by the peripheral belt 33 located inside the housing 11 and the resin layer 320 which is on the surface of the closing platform 110.

[0096] According to an embodiment illustrated in [Fig.2], the housing 11 includes a support piece 18 which is interposed, in the sealed cavity 30, between the upper surface of the filling resin 114 and the electronic means 14. The support piece 18 may include openings in particular to ensure the passage of the connectors 130 of the measuring means 12, 13.

[0097] According to one embodiment, the closing platform 110 is fitted, via its peripheral rim 1102, onto the assembly frame 170 of the intermediate piece. As illustrated in particular in Figures 4 and 6, the cohesive filling resin 114 provides a seal between the base piece 16, a portion of the peripheral partition 111, the assembly frame 170 of the intermediate piece 17, and the cohesive filling resin 114. Furthermore, the filling resin 114 also provides a seal between the tabs 171 and the base piece 16.

[0098] Still with reference to figures 4 and 6, the encapsulation resin 115 in the cohesive state ensures the seal between the assembly frame 170 of the intermediate part 17, the closing platform 110 and the filling resin 114.

[0099] As illustrated in Figures 1, 2, and 6, in one embodiment, the flowmeter 10 may include a cover 19. In this example, the cover 19 is fitted onto the closing platform 110. The cover 19 may have at least one window 190 arranged coaxially with at least one window 1107 of the closing platform 110. The window 190 allows the user to view a display screen of the flowmeter 10. The cover 19 may also include an opening 191 providing access to a selection button. The cover 19 may also include a lid 192 hinged to a fixed portion of the cover 19. The lid 192 serves, on the one hand, to protect the cover 19, and on the other hand, the elements of the flowmeter 10 that are accessible via the cover 19, such as the display screen, the selection button, etc.The cover 19 primarily protects the flow meter 10 from external aggressions such as shocks, and thus helps to improve the longevity of the flow meter 10.

[0100] As illustrated in [Fig.1 1], the invention also relates to a method of manufacturing 500 of a flowmeter conforming to an embodiment of the invention.

[0101] The manufacturing process includes a step 501 of mounting the measuring means 12, 13 to the pipe 20. As illustrated in [Fig.2] the mounting can be carried out using mechanical elements such as screws.

[0102] According to one embodiment, in which the housing 11 comprises three parts: the base piece 16, the intermediate piece 17, and the closing platform 110; the manufacturing process 500 includes an assembly step 502 of the housing 11. As illustrated in [Fig. 2], the intermediate piece 17, which carries the conduit 20, is fitted into the base piece 16. The connectors 130 of the measuring means 12, 13 are then salient within the internal space of the case 11.

[0103] According to one embodiment, the process 500 may include a pouring step 503 of the filling resin 114, in a fluid state, into the lower compartment of the internal space of the housing 11 up to a defined level. The filling resin 114 notably fills the lower compartment of the internal space and coats the conduit 20 equipped with the measuring means 12, 13. The connectors 130 remain protruding from the filling resin 114 in order to be connected to the electronic means 14. According to one embodiment, a peripheral shoulder 113 may be used as a filling limit for the internal space. The filling resin 114 may then be poured up to this shoulder 113 to control the filling level of the housing 11 during the pouring step 503.

[0104] According to this embodiment, the manufacturing process 500 may include a step 504 for forming a first sealing wall 31. The formation 504 of the first sealing wall 31 is achieved by setting the filling resin 114. Setting the resin corresponds to its transition from a fluid / viscous state to a cohesive state. This step can be carried out by polymerizing resin precursors or, alternatively, by drying the resin diluted in a solvent. Preferably, two resin precursors are used to perform the polymerization. The resin can be set at ambient temperature. After setting, the filling resin 114, in a cohesive state, isolates the pipe 20 and constitutes, by its upper surface, a first sealing wall 31. At the end of this step 504, the connectors 130 of the measuring means 12, 13 are protruding from the solidified filling resin 114.

[0105] The manufacturing process 500 includes a coupling step 505 of the electronic means 14 to the housing 11 and to the measuring means 12, 13. As illustrated in [Fig. 2], for this purpose mechanical connectors 141 can be assembled to the studs 173 of the intermediate part 17. The connectors 141 can be assembled through the support part 18. The studs 173 act as supports and allow the electronic means 14 to be positioned in the upper compartment of the internal space of the housing 11. During this coupling step 505, the battery 15 can also be inserted into its compartment 116, which is closed by a cover 1161 through which electrical connectors pass to connect the battery 15 to the electronic means 14.

[0106] The manufacturing process 500 also includes a step 506 of closing the housing 11 with a partition. In particular, in this example, the closing partition is formed by the closing platform 110. The fitting of the closing platform 110 onto the housing 11 provides a partitioned peripheral belt 33 that surrounds the electronic means 14. It should be noted that the peripheral belt 33 communicates with the lower compartment of the housing 11. According to one embodiment, the peripheral skirt 1105 is thus introduced into the internal space of the housing 11, while the peripheral rim 1102 is fitted onto the free edge 1110 of the peripheral partition of the housing 11. The cooperation between the peripheral skirt 1105 and the peripheral partition 111 forms, on the one hand, the peripheral belt 33, and on the other hand, at least one opening 1101 which communicates with the peripheral belt 33 and which is accessible from the platform 1103 of the closing platform 110.

[0107] The manufacturing process 500 includes a second step 508 of pouring an encapsulation resin 115, in a fluid state, onto the closing partition and into the peripheral belt 33 of the housing 11. In particular, the passage provided by the opening(s) 1101 between the tray 1103 of the closing platform 110 and the peripheral belt 33 allows the encapsulation resin 115 to flow into the peripheral belt 33. The peripheral belt 33 is delimited by the peripheral cavity 330, which extends between the peripheral skirt 1105 and the peripheral wall 111 to the filling resin 114, which is already in a cohesive state. The structure of the housing 11 allows the encapsulation resin 115 to be poured in a controlled manner without immersing the electronic means in the resin, thus forming a sealed cavity 30 around the electronic means 14.

[0108] In particular, the encapsulating resin 115 is poured onto the closing platform 110 and flows, through at least one opening 1101 provided on the closing platform 110, into the peripheral belt 33. Preferably, the closing platform 110 comprises several openings 1101 which are arranged between the plate 1103 and the peripheral rim 1102. More precisely, these openings 1101 are arranged between each spacer 1104 which connects the peripheral rim 1102 and the plate 1103. The flow of the resin through these openings 1101 allows the sealing wall to be formed on the surface of the closing platform 110 and the sealing peripheral belt 33 through a single, monolithic, sealed body made of encapsulating resin 115.

[0109] According to a particular embodiment of the invention, before setting, the encapsulation resin 115 is less viscous than the filling resin 114.

[0110] According to the embodiment which includes a single resin pouring step, the peripheral belt 33 is open to the lower compartment of the internal space of the housing 11. In contrast, according to the embodiment which includes two pouring steps, the filling resin 114 constitutes the bottom wall of the peripheral belt 33.

[0111] According to one embodiment, the encapsulation resin 115 and the filling resin 114 are identical.

[0112] The process 500 comprises a formation step 509, on the one hand, of a second The sealing wall 32 on the plate 1103 of the closing platform 110, and on the other hand, the sealing belt 33 which surrounds the electronic means 14 of the sealed cavity 30 of the flowmeter 10. The forming step 509 is carried out by setting the encapsulating resin 115. As with the filling resin, setting corresponds to its transition from a fluid to a cohesive state. The setting of the encapsulating resin 115 is preferably carried out by polymerization of resin precursors and can take place at room temperature.

Claims

Demands

1. Flow meter (10) comprising: - a casing (11) which includes partitions (110, 111, 112) delimiting an internal space of the casing (11), - a pipe (20) mounted through the internal space of the housing (11), the pipe (20) being configured to be connected to a network conveying a flow of fluid; - at least one cohesive filling resin (114) which partially fills the internal space and coats the pipe (20); - ultrasonic means for measuring the flow rate of a fluid flowing through the pipe (20), the means for measuring (12, 13) being coupled to the pipe (20); - a sealed cavity (30) comprising: • a first sealing wall (31) formed by the filling resin (114) in a cohesive state, • a second sealing wall (32) opposite the first sealing wall (31), the second sealing wall (32) comprises a layer (320) of encapsulation resin (115) in a cohesive state, • a peripheral sealing belt (33) comprising a cohesive encapsulating resin (115) surrounding electronic means (14), the peripheral belt (33) hermetically sealing the first sealing wall (31) and the second sealing wall (32) so as to form the sealed cavity (30); and the electronic means (14) of the flowmeter (10) being disposed in the sealed cavity (30) and connected to the ultrasonic measuring means (12, 13) through the sealed cavity (30).

2. Flowmeter (10) according to claim 1, wherein the peripheral belt (33) comprises a double wall which laterally encircles the sealed cavity (30), the double wall forming a peripheral cavity (330) in the internal space which is filled by the encapsulation resin (115) in the cohesive state.

3. Flowmeter (10) according to any one of claims 1 and 2, wherein the encapsulation resin (115) of the peripheral belt (33) adheres to the filling resin (114).

4. Flowmeter (10) according to any one of claims 1 to 3, wherein the second sealing wall (32) comprises a closure platform (110) which has at least one communicating opening (1101) with the peripheral belt (33), the resin layer (320) extending over the external face of the closure platform (110), the resin (115) of the peripheral belt (33) and the resin layer (320) are bonded at least through this opening (1101).

5. Flowmeter (10) according to claim 4, wherein the closing platform (110) has a peripheral rim (1102) which is coupled to the partitions (111) of the housing (11), the peripheral rim (1102) being connected to the closing platform (110) through a determined number of spacers (1104), a communicating opening (1101) with the peripheral belt (33) being disposed between two consecutive spacers (1104).

6. Flowmeter (10) according to any one of claims 4 and 5, wherein the closing platform (110) comprises a peripheral skirt (1105) which is configured to fit into the internal space of the housing (11) so as to form the peripheral belt (33) by cooperating with the partitions (111) of the housing (11).

7. Flowmeter (10) according to claims 5 and 6, wherein each spacer (1104) extends between the peripheral rim (1102) and the peripheral skirt (1105), the opening (1101) then communicating with the peripheral belt (33) which extends into the internal space of the housing (H).

8. Flowmeter (10) according to any one of claims 1 to 7, wherein the housing (11) has a peripheral shoulder (113) which extends over the inner face of the partitions (111) which delimit the internal space of the housing (11), the filling resin (114) extending into the internal space up to the level of the peripheral shoulder (113).

9. Flowmeter (10) according to any one of claims 1 to 8, wherein the housing (11) comprises a housing (116) receiving at least part of a battery (15) which powers the electronic means (14) and the ultrasonic measuring means (12, 13), the housing (116) being isolated from the pipe (20) by the filling resin (114).

10. Flow meter (10) according to any one of claims 1 to 9, wherein, the sealed cavity (30) includes a moisture absorber.

11. Flowmeter (10) according to claim 1, wherein the housing (11) comprises: - a base piece (16) which includes a base (160) of the housing (11) and walls (161) which are integrated with the partitions (111) of the housing (11), - an intermediate piece (17) which fits into the base piece (16), the intermediate piece (17) carrying the pipe (20) and comprising an assembly frame (170) which fits onto the walls (161) of the base piece (16) so as to define a peripheral partition (111) of the housing (11), and - a closing platform (110) which comprises: • a peripheral rim (1102) configured to fit onto the assembly frame (170) of the intermediate piece (17), and • a part which extends into the internal space and cooperates with the peripheral partition (111) in order to form the peripheral belt (33).

12. Flowmeter (10) according to claim 11, wherein the housing (11) includes a support piece (18) which is interposed between the filling resin (114) and the electronic means (14).

13. Flowmeter (10) according to any one of claims 1 to 12, wherein the filling resin is selected from the following resins: polyurethane resins, polyurethane resin derivatives, polyester resins, polyester resin derivatives, silicone resins, silicone resin derivatives.

14. Flowmeter (10) according to any one of claims 1 to 13, wherein the encapsulation resin is selected from the following resins: polyurethane resins, polyurethane resin derivatives, silicone resins, silicone resin derivatives.

15. A method for manufacturing (500) a flowmeter (10) according to any one of claims 1 to 14, characterized in that the method (500) comprises at least the following steps: - coupling (505) the electronic means (14) to the measuring means and to the flowmeter housing, the electronic means (14) being arranged in an upper compartment of the internal space of the case (11), - closing (506) the housing (11) with a partition, said partition being constituted by a closing platform (110), the fitting of the closing platform (110) onto the housing (11) providing a partitioned peripheral belt (33) which surrounds the electronic means (14), the peripheral belt (33) communicating with a lower compartment of the housing (11), - pouring (507) an encapsulation resin (115) in a fluid state at least onto the closure platform and into the peripheral belt of the housing, and - form (508) at least one sealing wall (31) on the closing platform (110) and one sealing wall in the peripheral belt (33) so as to produce a sealed cavity (30) around the electronic means (14), said sealing walls being formed by setting of the encapsulation resin (115), the setting of the encapsulation resin (115) corresponding to the passage of the encapsulation resin (115) from the fluid state to the cohesive state.

16. A manufacturing method (500) according to claim 15, which comprises, before the closing step (506) of the casing (11), the following steps: - Pour (503) a filling resin (114) into the lower compartment of the internal space of the housing (11) up to a defined level, the filling resin (114) coating the pipe (20) equipped with the measuring means (12, 13), - form (504) a sealing wall (31) of the sealing cavity (30) and constituting the bottom of the peripheral belt (33), the sealing wall (31) being formed by setting the filling resin (114), the setting of the filling resin (114) corresponding to the passage of the filling resin (114) from the fluid state to the cohesive state.

17. A manufacturing method (500) according to claim 16, wherein, before setting, the encapsulation resin (115) is less viscous than the filling resin (114).

18. A manufacturing method (500) according to any one of claims 15 to 17, wherein the encapsulation resin (115) is poured onto the closure platform (110) in a fluid state and flows into the peripheral belt (33) through at least one opening (1101) provided on the closure platform (110), the sealing wall (32) and the peripheral sealing belt (33) being formed from the same body of encapsulation resin (115).

19. A manufacturing method (500) according to any one of claims 15 to 18, wherein the setting time of the encapsulation resin (115) is longer than the setting time of the filling resin (114).

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