Flow meter, sealed cavity and mounting method

Abstract

The invention relates to a flow meter (10) comprising a housing (11) which is equipped with a pipe (20) and means (12, 13) for measuring a flow rate of fluid circulating in this pipe (20). The flow meter (10) is housed in the internal space of the electronics housing (14) which is held in a sealed cavity (30) formed by resin (114, 115). The invention also relates to the method for 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 flow such as water. In particular, the flow meter according to the invention comprises a sealed cavity comprising insulating resin walls. Prior art

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

[0003] However, this type of flow meter is generally installed in a humid environment. However, the walls of a flow meter housing have significant hydraulic diffusivity. Indeed, if the interior of the housing has low hygrometry, the humidity and / or water found in the flow meter's surrounding environment will necessarily infiltrate inside the housing. This phenomenon ultimately generates problems hindering the proper functioning of the flow meter. Indeed, humidity can act as a dielectric at the terminals of a battery and cause short circuits, in addition, certain quartz is very sensitive to humidity, which is likely to cause a problem with the quartz's behavior and cause a disruption in the metrology.

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

[0005] The first technique consists of providing an empty cavity, called a dry cavity, in the internal space of the housing. For this, the housing comprises walls between 5 and 10 mm thick which are generally made of glass walls or more generally of a mineral material. The exclusive use of glass or a mineral material is however avoided by manufacturers because it results in a significant additional production cost. Thus, at least one of the walls is generally made of glass while the others are made of plastic material. The glass walls make the mechanical design of the housing complex and expensive, particularly when it comes to creating the watertight connection with the housing which is generally made of plastic material. Indeed, this type of housing includes sealing elements between the different parts which constitute the housing, which also increases the complexity and cost of its design.

[0006] A second technique consists of flooding the internal space of the housing using a resin that exhibits sealing properties after solidifying in the internal space. This technique advantageously allows for the design of a housing with simplified structure and assembly while ensuring sealing between the different parts that make up the housing. It is thus possible to eliminate joints and sealing systems that are traditionally used to ensure sealing between the parts of the housing.

[0007] This technique prevents condensation in areas containing air around all cold spots with higher thermal capacity. However, when the resin is saturated with water, problems with the operation of the electronic elements due to humidity appear and compromise the reliability of the flow meter. In the case of a polyurethane type resin, for example, the commercial resins that can be found from the manufacturers "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. Statement 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 humidity 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 box which includes partitions delimiting an internal space of the box; - a pipe mounted through the internal space of the box, the channel lization is configured to be connected to a network carrying a flow of fluid; - at least one cohesive filling resin which partially fills the internal space and coats the pipe; - ultrasonic means for measuring the flow rate of a fluid flow passing through the pipeline, the measuring means being coupled to the pipeline; - a watertight 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 the cohesive state, • a peripheral sealing belt which comprises an encapsulating resin in a cohesive state and which surrounds electronic means, the peripheral belt sealingly assembles the first sealing wall and the second sealing wall so as to form the sealed cavity; and the electronic means of the flow meter being arranged in the sealed cavity and connected to the ultrasonic measuring means through the sealed cavity.

[0013] The use of a resin in a cohesive state to produce a sealed cavity makes it possible to isolate the electronics by simplifying the mechanical design of the housing. Indeed, according to the invention, the sealed resin cavity makes it possible, without drowning the electronics of the flow meter in the resin, to reduce the number of elements that make up the housing. For example, the resin makes it possible to avoid using seals between the different elements of the housing. In addition, the use of resin walls in a cohesive state to form the sealed cavity makes it possible to reduce the mass of the housing and the manufacturing costs. In this document, the cohesive state of the resin designates a resin that remains stable under the action of internal or external forces as opposed to the fluid state or the fluid state of the resin in which the latter is cast.A resin in a cohesive state can be solid or elastic as long as it forms a coherent volume of material that does not flow or disintegrate under the effect of external forces such as gravity.

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

[0015] In embodiments, the encapsulating resin of the peripheral belt adheres to the filling resin. The adhesion of the two resins to each other makes it possible to create a seal and thus to form the sealed cavity. According to these embodiments, the filling resin delimits the peripheral belt at the bottom. This makes it possible to close the sealed cavity without using an additional sealing element such as a gasket.

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

[0017] In embodiments, the closure platform comprises a peripheral rim which is coupled to the partitions of the housing, the peripheral rim being connected to the platform through a determined number of spacers, an opening communicating with the peripheral belt being disposed between two consecutive spacers. The peripheral rim makes it possible to control the pouring of the encapsulating resin while the spacers provide communicating openings which constitute passages allowing the flow of the resin and the formation of a single sealed body.

[0018] In embodiments, the closure platform comprises a peripheral skirt which is 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 makes it possible to form the double wall which 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 embodiments, the housing comprises a peripheral shoulder extending on the internal face of the partitions which delimit the internal space of the housing, the filling resin extending into the internal space up to the level of the peripheral shoulder. The shoulder makes it possible to control the pouring of the filling resin during the manufacturing process.

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

[0022] In embodiments, the sealed cavity comprises a moisture absorber. The moisture absorber allows for capturing condensation that may form inside the sealed cavity, for example, as a result of temperature changes in the environment surrounding the flow meter.

[0023] In embodiments, the housing comprises: - a base part which includes a base of the case and walls which fit into the partitions of the case, - an intermediate piece which fits into the bottom piece, the inter piece median carries the pipeline and includes an assembly frame which fits onto the walls of the bottom piece so as to define a peripheral partition of the housing, and - a closing platform which includes: • a peripheral rim configured to fit onto the assembly frame of the intermediate part, and • a part which extends into the internal space and cooperates with the peripheral partition in order to form the peripheral belt.

[0024] In embodiments, the housing comprises a support part which is interposed between the filling resin and the electronic means. The support part makes it possible to maintain the electronic means in a determined position in the sealed cavity.

[0025] In embodiments, the encapsulating 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 more preferably between 80 and 90. The Shore D hardness of the filling resin makes it possible to stiffen the housing in the vicinity of the pipe.

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

[0028] In embodiments, the encapsulating resin is selected 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 flow meter according to the invention. The method is characterized in that it comprises at least the following steps: - coupling the electronic means to the measuring means and to the flow meter 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 on 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 on the platform

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[0036]

[0037] closing and in the peripheral belt of the case, and - forming at least one sealing wall on the closure 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 has the same advantages as the flow meter, it allows a sealed cavity to be formed by pouring resin in a controlled manner into the flow meter housing. In embodiments, the manufacturing method comprises, before the step of closing the housing, the following steps: - 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, - forming 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 embodiments, prior to setting, the encapsulating resin is less viscous than the filler resin. The encapsulating resin can thus flow through small openings to fill the peripheral belt. In embodiments, the encapsulating resin is cast 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 encapsulating resin. In embodiments, the setting time of the encapsulating resin is longer than the setting time of the filler resin. In 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 belt. In embodiments, the setting time of the filler resin is 60 minutes, preferably less than 30 minutes and more preferably less than 10 minutes. In embodiments, the setting of the encapsulating resin is carried out at room temperature. In other embodiments, the setting time of the encapsulating resin can be accelerated by heating the housing.

[0038] In embodiments, the setting of the filler resin is carried out at room temperature. In other embodiments, the setting time of the resin can be accelerated by heating the housing. Brief description of the drawings

[0039] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This description is purely illustrative and should be read in conjunction with the appended drawings in which:

[0040] [Fig-1] is a perspective representation of an embodiment of a flow meter according to 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.l] in which the finishing cover has been removed.

[0043] [Fig.4] is a perspective representation of an embodiment of a die flowmeter conforming to an embodiment of the invention, in which neither the cover, nor an intermediate part of the housing nor the pipe are shown 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 [Fig.3].

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

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

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

[0048] [Fig.9] is a perspective representation of a bottom part of the case which is in accordance with an embodiment of the flow meter of the invention.

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

[0050] [Fig. 11] is a schematic representation of a method of manufacturing a flow meter according to the invention in the form of a flowchart. Description of the embodiments

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

[0052] As illustrated in Figures 1 to 6, the flow meter 10 comprises a housing 11 which comprises an internal space. In particular, the housing 11 comprises partitions 110, 111, 112 which delimit an internal space of the housing 11. Two partitions 110, 112 opposite one another and a peripheral partition 111 forming 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 on top, the partition 112 delimits the housing 11 on the bottom 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 comprises a pipe 20 mounted through the internal space of the housing 11. The pipe 20 is configured to be connected to a network carrying a fluid flow such as a hydraulic network. For this purpose, the pipe 20 has two ends 21, 22 which are respectively equipped with a connection end piece. In this example, the connection end piece has an external thread for connection to a network carrying a fluid flow.

[0054] As illustrated in Figures 4 to 6, the flow meter 10 comprises at least one filling resin 114 in the cohesive state which 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 chosen from the following resins: epoxy resin, polyurethane resin, silicone resin or their derivatives. For example, commercial polyurethane resins are available from the manufacturers “SIKA®” or “HENKEL®” and are sold in the form of two compounds to be mixed, a polymerizing agent also called hardener and a polyurethane precursor. The polymerizing agent may be an isocyanate compound and the polyurethane precursor a polyol compound. The resin may also be made of a thermoplastic polymer of the polyurethane, epoxy or silicone type in the fluid or solvated state which passes to the cohesive state when drying by evaporation of the solvent.

[0055] As can be seen in [Fig. 2], the flow meter 10 comprises ultrasonic measuring means 12, 13 for measuring the flow rate of a fluid flow passing 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 integrate 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° relative to the longitudinal axis of the pipe 20. According to an alternative embodiment, a single transducer cooperating with at least one mirror makes it possible to measure the flow of fluid flowing in the pipe 20.

[0056] As can be seen in Figures 5 and 6, the flow meter 10 comprises a sealed cavity 30 which can also be called a “dry cavity”. The sealed cavity 30 makes it possible to store electronic means 14 of the flow meter 10. The electronic means 14 can comprise an electronic card, a microprocessor, a memory, an electronic clock, a display screen and other electronic components necessary for the operation of the flow meter 10. In the example of Figures 5 and 6, the sealed cavity 30 is represented schematically by a dotted frame.

[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 coats the pipe 20. The filling resin 114 fills, in the cohesive state, a lower compartment of the housing 11 in which the pipe 20 is mounted through it. 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 further constitutes the first sealing wall 31 of the sealed cavity 30.

[0058] The sealed cavity 30 comprises 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 the cohesive state. The encapsulating resin 115 may be a dielectric resin. The encapsulating resin 115 may comprise a resin such as polyurethane resins, silicone resins or their derivatives. In addition, the encapsulating resin 115 has physicochemical properties which distinguish it from the filling resin 114.

[0059] According to one embodiment, the encapsulation resin 115 may be semi-rigid in the 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 expansions between the encapsulation resin 115 and the electronic components. These differential expansions generate stresses on the electronic components which may degrade. The semi-rigid nature of the encapsulation resin 115 in the cohesive state makes it possible to reduce these phenomena. In comparison, the filling resin 114 is considered rigid in the cohesive state. Indeed, the filling resin 114 may have, in the cohesive state, a Shore D hardness greater than 60, preferably greater than 70, and even more preferably between 80 and 90.This rigidity makes it possible to reinforce the mechanical resistance of the box 11 around the pipe 20.

[0060] According to another embodiment, the encapsulating resin 115 has a lower viscosity in the fluid state than the filling resin 114. This low viscosity provides the encapsulating resin 115 with 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 curing rate that is slower than the curing rate of the filler resin 114, and thus changes more slowly from the fluid / viscous state to the cohesive state. For example, the curing rate of the encapsulating resin 115 may be greater than 120 minutes, preferably greater than 180 minutes, and more preferably greater than 240 minutes. In comparison, the filler resin 114 has a curing rate of less than 60 minutes, preferably less than 30 minutes, and more preferably less than 10 minutes.

[0062] This slower curing rate allows the encapsulating resin 115 to flow into tight spaces and create a seal between several parts of the housing 11 without using additional sealing elements such as gaskets, for example.

[0063] As mentioned above, 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 in accordance with the invention.

[0064] As illustrated in Figures 4 to 6, the sealed cavity 30 also comprises a peripheral sealing belt 33 comprising an encapsulating resin 115, in the cohesive state, which surrounds the electronic means 14. The peripheral belt 33 forms a sealed connection 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 sealed body which is integrated into the structure of the housing 11 of the flow meter 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 inside the housing 11.

[0066] In particular, in one embodiment, the peripheral belt 33 comprises a double wall which laterally surrounds the sealed cavity 30. In this example, the double wall forms a peripheral cavity 330 in the internal space which is filled by the encapsulating resin 115. The encapsulating resin 115 of the peripheral belt 33 is preferentially cast in contact with the filling resin 114 which is already in the cohesive state. Consequently, the encapsulating resin 115 sets in the peripheral cavity 330 while it is in contact with the filling resin 114 and adheres to the filling resin 114 thus forming a sealed junction between the two resins 114, 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 solvates 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 lower peripheral cavity 330 while forming a sealed connection with the encapsulating 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 these purposes, 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 comprises 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 secured 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 plate 1103. The peripheral rim 1102 extends perpendicularly to the plate 1103. The peripheral rim 1102 is also projecting on either side of the plane in which the plate 1103 extends.

[0071] As is particularly visible in [Fig.8], the peripheral rim 1102 is offset relative to the plate 1103 and connected to the latter through a determined number of spacers 1104. As a result, an opening 1101 communicating with the peripheral belt 33 is arranged between two consecutive spacers 1104. The closing platform 110 thus comprises a plurality of openings 1101 which each communicate with the peripheral belt 33.

[0072] In particular, each opening 1101 provides a passage which allows, during the manufacture of the flow meter 10, the resin 115 to be poured onto the plate 1103 and to flow into the peripheral cavity 330 through one or more openings 1101. 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 belt 33 forms, with the resin layer 320, a single-piece sealed body. This sealed body cooperates with the outer surface of the filling resin 114 in order to form the sealed cavity 30.

[0073] As is 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 face of the housing 11. In this example, the peripheral skirt 1105 projects from the internal face of the closing platform 110. As can be seen in [Fig.8], the peripheral rim 1102 extends at least partly parallel to the peripheral skirt 1105. In particular, over a portion of the height of the peripheral skirt 1105, the peripheral rim 1102 covers the wall of the peripheral skirt 1105. The spacers 1104 thus extend between the peripheral skirt 1105 and the peripheral rim 1102 at least partly over the overlapping portion between the peripheral rim 1102 and the peripheral skirt 1105.

[0074] The peripheral skirt 1105 has dimensions which 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 which 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 promotes their fitting together. Here, the free edge 1110 has a shoulder complementary to the shoulder which is provided on the edge 1106 of the peripheral rim 1105. This complementarity facilitates the assembly and the mechanical strength of the housing 11.

[0076] In this example, the closing platform 110 comprises at least one transparent window 1107 arranged on the surface of the plate 1103. The window 1107 makes it possible to read information on a display screen arranged in the sealed cavity 30 opposite this window 1107. In this example, the closing platform 110 comprises two transparent windows 107. Each window corresponds, here, to a transparent bead which projects from the plate 1103 of the closing platform 110. According to another embodiment, the closing platform 110 may comprise a deformable button 1108 which 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 one embodiment, the electronic means 14 are attached to the internal face of the closing platform 110 in order to be kept fixed within the sealed cavity 30.

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

[0079] According to a non-illustrated embodiment of the invention, the sealed cavity 30 comprises a moisture absorber. The moisture absorber may consist of desiccant. The moisture absorber makes it possible to absorb the moisture which would pass into the sealed cavity 30 and / or the condensation of the moisture contained in the air during the formation of the sealed cavity 30. This makes it possible to extend the lifespan of the flow meter 10.

[0080] According to an embodiment illustrated in [Fig.5], the housing 11 comprises an internal peripheral shoulder 113 which extends on the internal 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 makes it possible, during the manufacture of the flow meter 10, to precisely control the filling level of the filling resin 114 in the internal space of the housing 11. In addition, the shoulder 113 also makes it possible to delimit the lower compartment from the upper compartment of the housing 11.

[0081] According to one embodiment, the housing 11 comprises a housing 116 which extends from a partition 112 of the housing 11 to the sealed cavity 30. In particular, the housing 116 extends from the partition 112 defining the bottom of the housing 110. The housing 116 receives at least a portion of a battery 15 which powers the electronic means 14 and the ultrasonic measuring means 12, 13. The battery 15 may comprise one or more accumulators. Preferably, the housing 116 receives the battery in its entirety. The housing 116 is advantageously isolated from the pipe 20 by the filling resin 114. Indeed, the housing 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 comprises a cover 1161 which has openings to ensure the passage of an electrical connector between the battery 15 and the electronic means 14. The cover 1161 ensures the sealing of the housing 116 and avoids any dielectric phenomenon at the terminals of the battery 15. In addition, the battery 15 may also comprise an impermeable 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 comprises a bottom piece 16 which integrates a bottom 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 bottom piece 16 may comprise two cutouts 162 arranged coaxially with respect to each other. The two cutouts 162 are formed respectively in two walls 161 opposite one another. 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 make it possible to fit the pipe 20 into the bottom piece 16 and in particular to receive 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 part 17 which fits into the bottom part 16. In this example, the intermediate part 17 carries the pipe 20 and comprises an assembly frame 170 which fits onto the walls 161 of the bottom part 16 so as to define the peripheral partition 111 of the housing 11. As can be seen in particular in [Fig. 10], the intermediate part comprises two lugs 171 which extend from the assembly frame 170. The lugs 171 are opposite each other and make it possible to assemble the pipe 20 to the intermediate part 17. For example, the intermediate part 17 can be produced by injection and therefore made in one piece.For these purposes, it is possible to use a carbon fiber-loaded polymer which makes it possible to provide a pipe 20 which has resistance to a fluid pressure, circulating in the pipe 20, which is greater than 75 bars.

[0086] Advantageously, the housing 11 comprises means for fitting the intermediate part 17 onto the bottom part 16. As is particularly visible in [Fig.9], the fitting means comprise an assembly edge 163 and an angle iron 164. The angle iron 164 extends parallel to the assembly edge 163. In this example, the assembly edge 163 projects from the angle iron 164.

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

[0088] In an embodiment illustrated in [Fig.9], the fitting means may comprise receiving lugs 165 of the pipe 20. In this example, the receiving lugs 165 project into the internal space of the bottom 16 of the housing 11. [Fig. 10] shows a particular arrangement, according to which the lugs 165 are arranged two by two along two opposite axes. In addition, the lugs 165 on a first axis are arranged in a staggered manner relative 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 arranged on a wall of the pipe 20. According to the embodiment which comprises two ultrasonic transducers 12, 13, the intermediate part 17 comprises as many receiving housings 172 as ultrasonic transducers 12, 13.

[0090] The intermediate part 17 can be equipped with members for holding the electronic means 14. The holding members make it possible to hold the electronic means 14 in a stationary position within the sealed cavity 30.

[0091] According to the embodiment illustrated in Figures 8 and 10, the holding members comprise two pads 173 which extend longitudinally from the pipe 20 towards the closing platform 110. Each pad 173 may comprise a central bore 1730 allowing the fixing of a mechanical connector 141 such as a screw as illustrated in particular in [Fig.2]. In addition, each pad 173 may comprise support ribs 1731. The pads 173 and the support ribs 1731 make it possible to hold the electronic means 14, through the electronic card, approximately in the center of the sealed cavity 30. The pads 173 control in particular the height position of the electronic means 14 within the internal space of the housing 11.

[0092] As illustrated in Figures 8 and 10, the holding members may also comprise at least one stop element 174 which is arranged against the walls of the assembly frame 170. In this example, the holding members comprise two stop elements 174 which are arranged opposite each other. The spacing 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 lower face of the plate 1103 of the closing platform 110. The stop elements 174 thus ensure assembly precision.

[0093] Furthermore, the stop elements 174 also make it possible to maintain the electronic means 14, through the electronic card, approximately in the center of the sealed cavity 30. The stop elements 174 make it possible to laterally control the position of the electronic means 14.

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

[0095] In the example of [Fig.4], the intermediate part 17 is not shown, this makes it possible to visualize the single-piece sealed body formed by the peripheral belt 33 located inside the housing 11 and the resin layer 320 which is on the surface from the closing platform 110.

[0096] According to an embodiment illustrated in [Fig.2], the housing 11 comprises a support part 18 which is inserted, in the sealed cavity 30, between the upper surface of the filling resin 114 and the electronic means 14. The support part 18 may comprise 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 fits, through its peripheral rim 1102, onto the assembly frame 170 of the intermediate piece. As illustrated in particular in FIGS. 4 and 6, the filling resin 114 in the cohesive state ensures the seal between the bottom piece 16, a portion of the peripheral partition 111, the assembly frame 170 of the intermediate piece 17 and the filling resin 114 also in the cohesive state. In addition, the filling resin 114 also ensures the seal between the ears 171 and the bottom piece 16.

[0098] Still with reference to figures 4 and 6, the encapsulating 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, according to one embodiment, the flow meter 10 may comprise a cover 19. In this example, the cover 19 is fitted onto the closure platform 110. The cover 19 may comprise at least one window 190 which is arranged coaxially with at least one window 1107 of the closure platform 110. The window 190 allows the user to consult a display screen of the flow meter 10. The cover 19 may also comprise an opening 191 giving access to a selection button. The cover 19 may also comprise a lid 192 which is hinged to a fixed portion of the cover 19. The cover 192 makes it possible, on the one hand, to protect the cover 19, and on the other hand, the elements of the flow meter 10 which are accessible via the cover 19, such as the display screen, the selection button, etc.The cover 19 mainly protects the flow meter 10 from external attacks such as shocks, and thus helps to improve the longevity of the flow meter 10.

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

[0101] The manufacturing method comprises 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 an embodiment, in which the housing 11 comprises three parts: the bottom part 16, the intermediate part 17 and the closing platform 110; the manufacturing method 500 comprises a step 502 of assembling the housing 11. As illustrated in [Fig.2], the intermediate part 17 which carries the pipe 20 is fitted into the bottom part 16. The connectors 130 of the measuring means 12, 13 are then protruding within the internal space of the housing 11.

[0103] According to one embodiment, the method 500 may comprise a step 503 of pouring the filling resin 114, in the fluid state, into the lower compartment of the internal space of the housing 11 up to a defined level. The filling resin 114 fills in particular the lower compartment of the internal space and coats the pipe 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 limit for filling 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 method 500 may comprise a step 504 of forming a first sealing wall 31. The formation 504 of the first sealing wall 31 is carried out by setting the filling resin 114. The setting of the resin corresponds to the passage of the latter from the fluid / viscous state to the cohesive state. This step may be carried out by polymerization of precursors of the resin or alternatively for drying the resin diluted in a solvent. Preferably, two resin precursors are used to carry out a polymerization. The setting of the resin may be carried out at room temperature. At the end of the setting, the filling resin 114, in the cohesive state, insulates 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 protrude from the solidified filling resin 114.

[0105] The manufacturing method 500 comprises a step 505 of coupling the electronic means 14 to the housing 11 and to the measuring means 12, 13. As illustrated in [Fig.2], for these purposes mechanical connectors 141 can be assembled to the pads 173 of the intermediate part 17. The connectors 141 can be assembled through the support part 18. The pads 173 act as a support and allow the electronic means 14 to be arranged 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 housing 116 which is closed by a cover 1161 allowing electrical connectors to pass through to connect the battery 15 to the electronic means 14.

[0106] The manufacturing method 500 also comprises a step 506 of closing the housing 11 with a partition. In particular, in this example the closing partition is constituted by the closing platform 110. The fitting of the closing platform 110 on the housing 11 provides a partitioned peripheral belt 33 which 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 plate 1103 of the closing platform 110.

[0107] The manufacturing method 500 comprises a second step 508 of casting an encapsulation resin 115, in the 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 plate 1103 of the closing platform 110 and the peripheral belt 33 allows a flow of the encapsulation resin 115 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 as far as the filling resin 114 which is already in the cohesive state. The structure of the housing 11 makes it possible to pour the encapsulation resin 115 in a controlled manner without drowning the electronic means in the resin in order to form a sealed cavity 30 around the electronic means 14.

[0108] In particular, the encapsulating resin 115 is poured onto the closure platform 110 and flows, through at least one opening 1101 provided on the closure platform 110, into the peripheral belt 33. Preferably, the closure 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 forms the junction between the peripheral rim 1102 and the plate 1103. The flow of the resin through these openings 1101 makes it possible to form the sealing wall on the surface of the closure platform 110 and the peripheral sealing belt 33 through a single, single-piece, sealed body which is 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 comprises a single resin casting step, the peripheral belt 33 is open onto the lower compartment of the internal space of the housing 11. On the other hand, according to the embodiment which comprises two casting 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 method 500 comprises a step 509 of forming, on the one hand, a second sealing wall 32 on the plate 1103 of the closing platform 110, and on the other hand, of the sealing belt 33 which surrounds the electronic means 14 of the sealed cavity 30 of the flow meter 10. The formation step 509 is carried out by setting the encapsulating resin 115. As for the filling resin, the setting corresponds to its passage from the fluid state to the cohesive state. The setting of the encapsulating resin 115 is preferably carried out by polymerization of precursors of the resin and can take place at room temperature.

Claims

Claims

1. Flow meter (10) comprising: - a housing (11) which comprises partitions (110, 111, 112) delimiting an internal space of the housing (11), - a pipe (20) mounted through the internal space of the housing (11), the pipe (20) being configured to be connected to a network carrying a flow of fluid; - at least one filling resin (114) in a cohesive state which partially fills the internal space and coats the pipe (20); - ultrasonic measuring means (12, 13) for measuring the flow rate of a fluid flow passing through the pipe (20), the measuring means (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 the cohesive state, • 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 the cohesive state, • a peripheral sealing belt (33) which comprises an encapsulating resin (115) in a cohesive state which surrounds electronic means (14), the peripheral belt (33) sealably assembles 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 flow meter (10) being arranged in the sealed cavity (30) and connected to the ultrasonic measuring means (12, 13) through the sealed cavity (30).

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

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

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

5. Flow meter (10) according to claim 4, wherein the closing platform (110) comprises 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 arranged between two consecutive spacers (1104).

6. Flow meter (10) according to 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. Flow meter (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. Flow meter (10) according to one of claims 1 to 7, in which the housing (11) comprises a peripheral shoulder (113) which extends on the internal 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. Flow meter (10) according to one of claims 1 to 8, in which 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 one of claims 1 to 9, in which, the sealed cavity (30) includes a moisture absorber.

11. Flow meter (10) according to claim 1, wherein the housing (11) comprises: - a bottom part (16) which comprises a bottom (160) of the housing (11) and walls (161) which fit into the partitions (111) of the housing (11), - an intermediate part (17) which fits into the bottom part (16), the intermediate part (17) carries the pipe (20) and comprises an assembly frame (170) which fits onto the walls (161) of the bottom part (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 part (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. Flow meter (10) according to claim 11, wherein the housing (11) comprises a support part (18) which is interposed between the filling resin (114) and the electronic means (14).

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

14. Flow meter (10) according to one of claims 1 to 13, in which the encapsulating resin is chosen from the following resins: polyurethane resins, polyurethane resin derivatives, silicone resins, silicone resin derivatives.

15. Manufacturing method (500) of a flow meter (10) according to 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 housing of the flow meter, the electronic means (14) being arranged in an upper compartment of the internal space of the housing (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) on 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 encapsulating resin (115) in a fluid state at least onto the closing platform and into the peripheral belt of the housing, and - forming (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 encapsulating resin (115), the setting of the encapsulating resin (115) corresponding to the passage of the encapsulating resin (115) from the fluid state to the cohesive state.

16. Manufacturing method (500) according to claim 15, which comprises, before the step of closing (506) the housing (11), the following steps: - Pouring (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), - forming (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. The manufacturing method (500) of claim 16, wherein, prior to setting, the encapsulating resin (115) is less viscous than the filling resin (114).

18. Manufacturing method (500) according to one of claims 15 to 17, wherein the encapsulating resin (115) is cast 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 by the same body of encapsulating resin (115).

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

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