Pressure sensor device, in particular for a gaseous fluid

Abstract

A pressure sensor device comprises a support body and a detection arrangement comprising: a pressure sensitive element (3) having a detection membrane; and a circuit arrangement (3e, 8, 11, 30) comprising a control circuit (30) comprising a circuit support (30a) and an electrical connection element (3e). A pressure sensitive element (3) is associated with the support body such that a majority of the detection membrane is directly exposed outside the support body (2) for fluid access. The support body (2) has an engagement portion (4), in particular configured for insertion into a passage of a conduit of a fluid, having a distal end portion (5b) at which the pressure sensitive element (3) is constrained. A circuit support (30a) is associated with a positioning body (20) associated with a pressure sensitive element (3), an electrical connection element (3e) constrains the circuit support (30a) to the pressure sensitive element (3), the positioning body (20) being disposed at least partially between the printed circuit support and the pressure sensitive element to form a detection unit (10). The detection unit (10) is fixed to a distal end portion (5b) of the engagement portion (4) by means of at least one fixing element (6).

Description

Technical Field

[0001] The present invention relates to a pressure sensor device and has been developed with particular reference to a sensor device intended for detecting the pressure of a fluid subject to at least partial freezing, in particular a gaseous fluid, such as a gaseous fluid containing moisture or water vapor or a suspension susceptible to freezing. Background Art

[0002] Pressure sensor devices for fluid media are well known. Such devices generally include a pressure-sensitive element having a substrate which defines or has associated therewith an elastically deformable sensing membrane. On the side of the membrane not exposed to the fluid, there are associated elements (generally capacitive, resistive or piezoresistive elements) for detecting deformation or bending of the membrane itself, in order to obtain information representative of the degree of deformation or bending, which in turn represents the value of the pressure of the fluid to which the membrane is exposed.

[0003] Miniature sensing elements formed from semiconductor materials (usually starting with silicon chips) are known, but, generally speaking, for applications requiring greater ruggedness, the sensing elements are larger and are usually formed from ceramic materials such as alumina or from metallic materials such as stainless steel.

[0004] The pressure sensor device in which these sensitive elements are mounted generally comprises a housing body configured to obtain electrical and hydraulic connections, in which the sensitive element and any associated control electronics are mounted. For the purpose of electrical connection, the housing body generally defines a connector body with electrical connection terminals. For the purpose of hydraulic connection, the housing body defines a plastic or metal port configured for connection with a circuit in which the fluid whose pressure must be measured is located. The port generally has a tubular shape and therefore defines a passage through which the fluid can reach a chamber defined inside the housing body, which is partly defined by the membrane of the sensitive element, so that the same fluid can reach the membrane.

[0005] The inlet channel and the detection chamber may be subject to fluid accumulation even after interruption of the fluid circulation in the corresponding circuit. If the sensor device is operated under conditions of low ambient temperature, these possible accumulations of liquid are potentially dangerous with respect to the reliability of operation and the integrity of the sensitive element. In such cases, in fact, the liquid residues may freeze, thus increasing in volume and exerting considerable mechanical stress on the sensitive element.

[0006] In order to overcome this problem, solutions have been proposed in which a protective element formed of an elastically compressible material is arranged inside the fluid inlet channel and / or in the detection chamber. In these solutions, the volume increase caused by the freezing of the fluid residue is compensated by the volume reduction of the protective element. These solutions are relatively simple, but the disadvantage of the associated sensor devices is that a relatively long waiting time is required so that the device itself can resume normal operation (essentially, the device cannot measure the pressure in the fluid unless the fluid is completely thawed). This disadvantage is particularly evident in the case where the fluid subjected to pressure detection is or includes a gas with a moisture or water vapor content or a fluid that may freeze.

[0007] A typical example in this sense is a fuel cell, where the hydrogen and air present on the anode and cathode sides, respectively, may have a certain moisture content. Even in these cases, the moisture present in the gases may accumulate in the inlet channels and the detection chamber, even for a long time, in particular when the operating temperature drops below the dew point. In these cases, in the event that the temperature then drops below the freezing point, the trapped moisture may freeze and hinder or modify the operation of the detection membrane, preventing the sensor device from correctly measuring the pressure of the fluid inside the channel in which the fluid flows.

[0008] In order to overcome the disadvantages associated with the possible freezing of fluid or moisture residues, some solutions have also been proposed in which the inlet channel is filled with an incompressible fluid. In these solutions, the pressure of the fluid subjected to the pressure measurement can then exert a stress on the incompressible fluid, which in turn transmits the stress to the sensing diaphragm. In this way, the sensor device does not have a duct or chamber in which an accumulation of liquid or moisture may occur, thus avoiding the aforementioned disadvantages. On the other hand, these solutions lead to a complex production process for the sensor device and are therefore very expensive. A related disadvantage of these solutions is related to the impossibility of equipping the device with means for detecting the temperature of the fluid, unless significant complexity is required in the implementation of the device itself.

[0009] A simpler solution to the indicated problem is known from KR 20190059433 A, on which the preamble of claim 1 is based. In this solution, the pressure sensor device is designed such that the detection membrane of the sensitive element is directly exposed to the same gas fluid inside the pipe in which the gas circulates.

[0010] Appendix to the cited prior art documents Figure 1 and attached Figure 2 Corresponding to Figure 5 and Figure 6In these figures, 700 indicates the sensor body or cover, within which is placed the circuit support 400, supporting the control electronics of the device.

[0011] The lower side of the circuit support 400 has a substrate 200 directly associated therewith, and at the lower end of the substrate, the detection film 300 is fixed by means of a fixing material 220. The substrate 200 and the film 300 are made of a ceramic material, and the fixing material 220 can be a glass frit. The sensitive element consisting of the substrate 200 and the film 300 associated therewith is equipped with a terminal or pin 500 for connecting to the circuit support 400, and the terminal 710 mounted on the cover 700 is also electrically connected to the circuit support.

[0012] As especially in Figure 2 As can be seen in FIG. 1 , in the assembled state, the sensitive element constituted by substrate 200 and membrane 300 protrudes under cover 700 to which it is fixed by means of circuit support 400 and epoxy layer 600 .

[0013] In order to fix the substrate 200 and the corresponding circuit support 400 to the cover 700 and to ensure that the sensor is airtight with respect to the external environment, an epoxy resin 600 is injected at one end of the cover 700. In order to improve the assembly, the substrate 200 has an upper annular throat 210 in which the resin 600 can be retained. In such an assembled state, the substrate 200 and the membrane 300 protrude relative to the cover 700. The substrate 200 also has a lower groove forming a seat for an annular gasket 220 intended to form a seal relative to the surface of the radial passage in which the sensitive element 200-300 is inserted. As in particular in Figure 2 As shown in FIG. 1 , under operating conditions, the sensitive element composed of the substrate 200 and the membrane 300 is inserted into a radial passage of the pipe 110 in which the gas flows, so that the membrane 300 is directly exposed to the gas.

[0014] As can be seen, therefore, in the assembled state, the membrane 300 is directly exposed to the gas flowing into the conduit 110, eliminating or otherwise minimizing possible moisture accumulation points that are inevitably present in the same gas.

[0015] The type of construction envisaged in the prior art document is complex and expensive, also due to the way of installing the device, which must be assembled so that its sensitive component is directly inside the corresponding passage of the gas circulation pipe. In addition, the fact that a radial seal is formed directly between the substrate 200 of the sensitive part and the passage of the pipe determines the risk of high friction and / or torsion during insertion, thus generating abnormal mechanical stresses that may also originate from operating conditions (such as vibrations), which may damage the sensitive part and / or the circuit support. This risk is also partially increased by the fact that the sensitive element is connected to the circuit support by thin terminals and is fixed only by means of a thin layer of epoxy resin. Summary of the invention

[0016] In general, the present invention aims to create a pressure sensor device, in particular a pressure sensor device intended for use in combination with gaseous fluids, the construction of which is simple and economical, which is easy to assemble and highly reliable. According to the invention, this and other objects, which will become clearer hereinafter, are achieved by a pressure sensor device having the features of the attached claims. The claims form an integral part of the technical teaching provided herein in relation to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further objects, features and advantages of the present invention will become apparent from the following detailed description made with reference to the accompanying drawings, provided as non-limiting examples only, in which:

[0018] Prior art represented by KR 20190059433 A Figure 1 and Figure 2 They are Figure 5 and Figure 6 a replica of;

[0019] Figure 3 , Figure 4 and Figure 5 are schematic diagrams of a perspective view, a cross-sectional view and a partially exploded view, respectively, of a pressure sensor device according to a possible embodiment;

[0020] Figure 6 yes Figure 5 A partially exploded schematic diagram of two components of the device,

[0021] Figure 7 and Figure 8 are schematic diagrams of a perspective view and a partially exploded view, respectively, of a detection unit of a pressure sensor device with a corresponding sealing element according to a possible embodiment;

[0022] Fig. 9 is a schematic exploded view of a sensitive element of a pressure sensor device according to a possible embodiment;

[0023] Fig.10 and Fig.11 yes Figure 7 and Figure 8 Schematic exploded views of a detection unit of the type shown from different angles;

[0024] Fig.12 and Fig.13 Belongs to Fig.10 and Fig.11 a schematic perspective view of a positioning body of a detection unit of the type shown;

[0025] Fig.14 yes Figure 3-Figure 5 A partially cut-away perspective view of a portion of a device;

[0026] Fig.15 is Figure 4 Details on a larger scale;

[0027] Fig.16 and Fig.17 are two schematic cross-sectional views intended to illustrate two possible configurations for the use of a pressure sensor device according to possible embodiments of the present invention;

[0028] Fig.18 is with Figure 3 A similar schematic perspective view of a possible variant embodiment;

[0029] Fig.19 is with Figure 3 A schematic perspective view similar to that of FIG. 1 relates to a pressure sensor device according to another embodiment;

[0030] Fig. 20 and Fig.21 is with Fig.14 and Fig.15 Similar views of the view, involving Fig.19 Embodiments of

[0031] Fig. 22 is with Figure 3 A schematic perspective view similar to that of FIG. 1 relates to a pressure sensor device according to another embodiment;

[0032] Fig.23 and Fig.24 is with Fig.14 and Fig.15 Similar views of the view, involving Fig. 22 Embodiments of

[0033] Fig.25 is a schematic perspective view of a pressure sensor device according to another embodiment;

[0034] Fig.26 and Fig. 27 is with Fig.14 and Fig.15 Similar views of the view, involving Fig.25 Embodiments of

[0035] Fig.28 and Fig.29 are schematic diagrams of a cross-sectional view and a partially cut-away perspective view of a sensitive element of a pressure sensor device according to another possible embodiment;

[0036] Fig.30 and Fig.31 are schematic diagrams of a cross-sectional view and a partially cut-away perspective view of a sensitive element of a pressure sensor device according to another possible embodiment;

[0037] Fig.32 is a partially cut-away schematic perspective view of a sensitive element of a pressure sensor device according to another possible embodiment;

[0038] Fig.33 , Fig.34 and Fig.35 is a schematic cross-sectional view intended to illustrate other possible embodiments of the present invention;

[0039] Fig.36 and Fig.37 Respectively through Fig.19 and Fig.21 Similar views of the drawings illustrate possible variant embodiments;

[0040] Fig.38 yes Fig.37 Magnified details of

[0041] Fig.39 and Fig.40 Respectively through Fig.19 and Fig.21 A similar view shows another possible variant embodiment;

[0042] Fig.41 yes Fig.37 Magnified details of

[0043] Fig.42 is a schematic perspective view of a detection unit of a pressure sensor device according to a possible variant embodiment; and

[0044] Fig.43 Through Fig.15 A similar view shows Fig.42 The assembly status of the detection unit. DETAILED DESCRIPTION

[0045] Reference to "embodiment" in this specification indicates that a specific configuration, structure or feature described in the embodiment is included in at least one embodiment. Therefore, phrases such as "in one embodiment" that may exist in different places in this specification do not necessarily refer to the same embodiment. In addition, the specific configuration, structure or feature described or shown can be combined in any appropriate manner in one or more embodiments, even different from those embodiments described. The reference used here is only for convenience, and therefore does not limit the scope of protection or the scope of the embodiment. The spatial references used herein (such as "upper", "lower", "top", "bottom", etc.) are only for convenience, and with reference to the examples shown in the figures. In the figure, the interpenetration of some elements (such as some sealing elements or some electrical contact elements) described is intended to highlight the original shape of the element itself before elastic deformation after compression.

[0046] First reference Figure 3-Figure 6 , reference numeral 1 denotes as a whole a pressure sensor device according to a possible embodiment, in particular a pressure sensor device for use in combination with a fuel cell. The device 1 comprises a support body 2, to which a pressure detection arrangement is associated. For example, the support body 2 can be made of molded plastic, but metallic materials, or a combination of said materials, are not excluded. The aforementioned detection arrangement comprises a pressure-sensitive element 3 and a circuit arrangement described below, the pressure-sensitive element having an elastically deformable detection membrane 3a. As can be seen, for example, in Figure 3 In the embodiment, the sensitive element 3 is associated with the supporting body 2 so that a large part of the detection membrane 3a is directly exposed to the outside of the supporting body 2 for access by the fluid, as explained below. For this purpose, in various embodiments, the sensitive element 3 is associated with the body 2 so as to be located outside the body itself, but preferably protected by the body 2 or by a protective element applied thereto. In the following, it is assumed that the fluid in question is a gaseous fluid.

[0047] In various embodiments, the support body 2 has an engagement portion 4, which is particularly configured for insertion into the passage of a pipe for a fluid whose pressure must be detected, as explained below. In a non-limiting example, the body 2 has an upper portion, which has a larger cross-sectional dimension relative to the engagement portion 4, from which the engagement portion extends. However, in a possible actuation variant, the body 2 can be extended only axially (for example, with a substantially cylindrical cross section), in which case only the lower portion of this axially extended body obtains the engagement portion 4.

[0048] The engagement portion 4, which is preferably substantially cylindrical, has a proximal end portion and a distal end portion, the proximal end portion being for example Figure 3-Figure 4The proximal end portion is closer to the portion of the body 2 that must be kept outside the fluid conduit, and the distal end portion is, for example, Figure 5-Figure 6 5b, which is further away from the part of the body 2 that must remain outside the fluid conduit. The pressure-sensitive element 3 is constrained at the distal end portion 5b by at least one fixing element, such as the element indicated by 6. In various embodiments, the fixing element performs the function of partial protection of the sensitive element 3. The joining portion 4 is preferably provided with sealing means on the outside: in the example, the portion 4 defines for this purpose an intermediate seat 4a for positioning an elastomeric sealing ring 7. The seat 4a is located in a position intermediate the proximal end 5a and the distal end 5b of the joining portion 4.

[0049] The detection arrangement comprises a plurality of electrical terminals, for example three terminals, for connecting the device 1, one of which is Figure 4 8. As can be seen in the figure, the terminal 8 has a proximal end portion 8a, which protrudes in the tubular portion 2a of the body 2 so as to obtain a multi-pole electrical connector. The distal end portion 8b of the terminal 8 extends in the body 2, preferably as far as the interior of the engagement portion 4. In the example, the proximal end portion and the distal end portion of the terminal 8 are substantially flat and parallel, connected together by a straight middle portion 8c. Without impairing the function of the terminal 8, the terminal can still have a shape and position different from the illustrated case.

[0050] When formed from a plastic material, the body 2 may be molded directly over the terminals 8 and may define an internal cavity that is Figure 4-Figure 5 In this case, the body 2 may include a cover 2b for closing the cavity. The cavity C may be used to make the body 2 lighter and / or may be useful for keeping the terminal 8 in place during the overmolding phase of the body 2.

[0051] As will become clearer later, the sensitive element 3 is part of a detection unit, indicated as a whole in the figures by 10, which is mounted at a distal end portion 5b of the engagement portion 4 of the body 2, said portion 5b being particularly configured for insertion into a conduit passage for a fluid conduit whose pressure must be detected. For this purpose, in various embodiments, this distal end portion 5b defines a Figure 6 A housing indicated by C' is shown, which is open downward (ie, toward the outside of the main body 2) (refer to the figure), and the aforementioned unit 10 is at least partially received in the housing.

[0052] from Figure 4 and Figure 6As can be seen in the figure, in a possible embodiment, the engaging portion 4 has a transverse wall 2c which defines the bottom of the housing C', at which a through seat (not shown), preferably an axial through seat, for a corresponding contact element 11 is defined; for this purpose, the aforementioned through seat is defined in the wall 2c, for example at a formed position or thickened position of the wall. In various embodiments, the contact element 11 is an electrically conductive elastic contact element, which preferably does not require welding, such as a compression contact element, as explained below. In the non-limiting example depicted, the element 11 is substantially in the form of a helical spring; alternatively, the contact element 11 can have another shape, for example at least partially arched, such as a substantially "S" or "C" shape.

[0053] Figure 7 and Figure 8 A possible implementation of the aforementioned detection unit 10 is shown, which has a corresponding annular sealing element 12 .

[0054] In addition to the above-mentioned sensitive element 3, the unit 10 also includes a control circuit 30, which is part of the circuit arrangement of the device, and the arrangement also includes an electrical connection element, which electrically connects the sensitive element 3 to the control circuit 30. In various embodiments, the unit 10 also includes a positioning body 20, which is preferably configured as a separate component relative to the circuit 30 and relative to the sensitive element 3 (but it can have a shape that can be connected or fixed to at least one of the control circuit 30 and the sensitive element 3).

[0055] The sealing element 12, which is preferably configured to achieve an axial seal, at least partially surrounds the unit 10, in particular substantially at the positioning body 20 (if the positioning body is present). In various embodiments, a boss or radial protrusion 12a ( Figure 8 ), which allows the element itself to be mounted on the unit 10 in a centered position and / or with a slight elastic interference. The projection 12a may not be present, in which case the inner diameter of the element 12 will enable it to be mounted on the unit 10 in a centered position and / or with a slight elastic interference.

[0056] exist Fig. 9In the figure there are possible implementations of a sensitive element 3 schematically represented in an exploded view, which is preferably a non-miniaturized element (this means that the element 3 is not of the type obtained from a chip in a semiconductor material such as silicon). In various embodiments, the element 3 comprises a substrate 3b to which the membrane is attached by means of a suitable fixing material 3c. For example, if the membrane 3a and the substrate 3b are made of a ceramic material such as alumina, the fixing material 3c may be a glass frit or a glue. The material 3c is arranged in an annular configuration in the radially outermost areas of the opposite faces of the membrane and the substrate and has a certain thickness so that a chamber is defined between the membrane and the substrate (see Fig.28 and Fig.30 3f), or in any case have enough space to allow elastic bending of the membrane. Preferably, the material 3c realizes a gas-tight seal between the membrane 3a and the substrate 3b.

[0057] The sensitive element 3 is provided with a device for detecting elastic deformation or bending of the membrane 3a. In various embodiments, on the inner side of the membrane 3a (i.e. its face facing the substrate 3b), a sensitive element 3d is arranged according to known techniques, for example a piezoelectric or resistive element arranged in a bridge configuration (in particular a Wheatstone bridge). According to techniques known per se, the detection element 3d of the sensitive element 3 is connected in signal communication with a connection terminal or pin 3e by means of a conductive track not shown; in the example, the pin 3e is fixed through a corresponding hole defined in the substrate 3b and is arranged in the radially outermost annular area of ​​the upper face of the substrate 3b so as not to hinder the deformation of the membrane 3a. In various preferred embodiments, the pin 3e forms a connecting element for electrically connecting and mechanically constraining the sensitive element 3 to the circuit 30, between which the positioning body 20 is set.

[0058] Fig.10 and Fig.11A possible implementation of a detection unit 10 is shown, comprising a sensitive element 3, a positioning body 20 and a control circuit 30. The control circuit comprises a printed circuit support (or a board of a PCB (printed circuit board)) 30a, made of electrically insulating material or electrically insulated, for example, by depositing an insulating layer, on which there are deposited tracks (not highlighted) of conductive material, according to a technique known per se, for connecting electrical and electronic components 31, which are part of the control circuit 30 of the sensor device; the referenced components preferably comprise integrated circuits or the like 31a, such as a microcontroller or an ASIC (application specific integrated circuit) and / or a memory device. The circuit support 30a has through holes, provided with a conductive coating 32, to which some of the aforementioned tracks are connected; the coating 32 may comprise a surface metallization of the holes, shaped so as to define corresponding pads on at least one of the two opposite faces of the board 30a, to which at least some of the aforementioned conductive tracks are connected. In the mentioned holes there are pins 3e of the inserted sensitive element 3 (see for example Figure 8-Figure 9 ), which pin is electrically and mechanically connected (e.g., by soldering or tinning) to a coating or pad 32.

[0059] In various preferred embodiments, on one face (here called the upper face) of the circuit support 30a, contact pads 33 are provided, to which some of the aforementioned conductive tracks are connected, intended for connection with the contact elements 11, as explained below.

[0060] In various embodiments, the positioning body 20 and the circuit support 30a have corresponding coupling elements configured for identifying the mounting position of the circuit support 30a on the positioning body 20. In the case illustrated in the figures, for this purpose, the circuit support 30a has a peripheral seat or recess 34, preferably a radial seat or recess. In the example shown, in the case of a substantially circular peripheral contour of the circuit support 30a, there are three radial recesses 34 substantially at 120° to each other. The circular shape of the circuit support is not an essential feature.

[0061] exist Fig.12 and Fig.13 3 shows the positioning body 20 separately. In this example, the overall outer contour of the body 20 is substantially circular, which is consistent with the outer contour of the sensitive element 3 and the circuit support 30a. However, in other embodiments, the above contour can be different from the illustrated contour, such as substantially quadrilateral (square or rectangular) or polygonal with more than four sides (such as hexagonal).

[0062] The body 20 is preferably made of an electrically insulating material, such as a moulded plastic material, and has an annular peripheral wall 21 defining a central passage 22, for example having a substantially polygonal shape or having a profile obtained by linear and / or curved drawing.

[0063] The body 20 defines a support element 23 for the circuit support 30, here constituted by a radial projection on the inner side of the peripheral wall 21, that is to say on the wall of the central passage 22; the projection 23 forms a first positioning means for identifying the axial position between the two parts in question, and has an upper surface 23a identifying the support plane for the circuit support 30a. The body 20 preferably has a second positioning element at its upper face, preferably in the form of an axial projection 24 which, as will be seen, forms an element for coupling with the circuit support 30a, for identifying the reciprocal angular position between the two parts in question.

[0064] In various preferred embodiments, the positioning body 20 and the distal end portion 5b of the engagement portion 4 have corresponding coupling elements configured to identify a unique installation position of the detection unit 10 relative to said distal end portion 5b. In the example shown, at one of the axial protrusions of the body 20 (indicated by 24' in the figure), a seat or recess 25 is defined, which is intended to be used for engagement with a corresponding positioning element 13 (see for example Figure 6 ) connection, the positioning element is defined at the aforementioned distal end portion 5b, in particular within the housing C'.

[0065] The radial protrusions 23 are preferably located at positions corresponding to those of the radial projections 24 , but may differ in number and / or position and / or shape.

[0066] To obtain the unit 10, the control circuit 30 or the support 30a is arranged on the positioning body 20 so that the positioning recess 34 of the control circuit is coupled with the positioning protrusion 24 of the positioning body, as in Figure 8 Of course, the coupling means here illustrated by the protrusion 24 and the recess 34 may be of a different type or shape.

[0067] The circuit support 30a is positioned so that it supports the contact pads 33 ( Fig.10 ) with the surface facing up. Then, Fig.12 As shown, the lower surface of the positioning body 20 is placed on the upper surface of the sensitive element 3, and the pin 3e protrudes from it. The pin passes through the central passage 22 ( Figure 12-13 ), and can therefore be inserted into a corresponding hole provided with a conductive coating 32 on the support 30a.

[0068] The pins 3e are then soldered or otherwise fixed (for example, by means of paste or conductive glue) relative to the coating or pad 32 in order to obtain an electrical and mechanical connection between the circuit 30 and the sensitive element 3. Thus, the circuit support 30a is mounted on the positioning body 20, which in turn is supported by the sensitive element 3, and the electrical connection elements represented by the pins 3e constrain the support 30a to the sensitive element 3, with the body 20 interposed therebetween, forming the detection unit 10. Therefore, preferably, the sensitive element 3 indirectly supports the circuit 30 via the body 20.

[0069] It should be understood that in this way, the unit 10 forms an assembly which can be preassembled and which can be easily handled during the production phase, which assembly may already be equipped with the sealing element 12, for example with clear advantages in the automated production and / or handling and warehouse management of preassembled parts, and also in the form of different types of final pressure sensors for subsequent production.

[0070] It should be noted that the connecting element, i.e. pin 3e, can be replaced by a surface mount terminal (surface mount technology) on the upper surface of the substrate 3b of the sensitive element 3, which is then electrically connected (e.g., by tinning) to the circuit holder 30a in a manner similar to pin 3e.

[0071] Another possibility is to replace the pins 3e with connecting pads on the upper surface of the substrate 3b and to obtain a connection between these pads and corresponding pads on the circuit support 30a with the aid of elastic contact elements (for example, contact elements of the type represented by 11); in this case, the aforementioned elastic contact element can have a first end thereof, which is soldered to the pad on the upper surface of the substrate 3b using surface mounting technology and is tinned at its opposite end to the corresponding pad on the circuit support 30a.

[0072] For example, from Figure 8 , Figure 10-11 and Fig.15 It is understood that, in the assembled state of the unit 10, the circuit support 30a extends substantially parallel to the sensitive element 3 or its membrane 3a. From the same figure, it can be seen that the circuit support 30a preferably has a smaller cross-sectional area (i.e., lateral overall dimension) than the sensitive element 30; preferably, the positioning body 20 also has a smaller cross-sectional area (i.e., lateral overall dimension) than the sensitive element 30. Likewise, as a preferred measure, the circuit support 30a and / or the positioning body 20 and / or the sensitive element 30 have a cross-sectional area (i.e., lateral overall dimension) that is not greater than the cross-sectional area of ​​the distal end portion 5b.

[0073] The distal end portion 5 b of the engagement portion 4 of the support body 2 is preferably shaped to accommodate a portion of the detection unit 10 internally, in particular a portion comprising the circuit support 30 a and / or at least a portion of the positioning body 20 .

[0074] As already indicated, in various preferred embodiments, the distal end portion 5b defines a housing C' (see also Figure 6 ), wherein the detection unit 10 is at least partially received. Fig.14 and Fig.15 It is shown that, in the assembled state of the sensor device, the circuit support 30a and a part of the positioning body 20 are located inside the housing C′.

[0075] Preferably, the distal end portion 5b, in particular within the cavity C', also defines one or more axial rest or positioning surfaces for positioning at least one of the body 20 and the sensitive element 3. Figure 14-15 In the example shown, 5a' denotes an axial positioning surface, and the axial elements 24 and 24' (see also Figure 8 and Fig.13 ) can abut against the axial positioning surface (it should be noted that, for example, considering the elastic mounting, the axial element 24 can abut against the abutment surface 5a' only due to external stress).

[0076] Preferably, a seat is also opened in the housing C' for the contact element 11 defined in the structure 2d of the wall 2c, as in Fig.15 It can be seen in.

[0077] In various embodiments, the detection unit 10 and the distal end portion 5b of the engagement portion are configured so that the unit 10 can be mounted relative to the portion 5b from the outside from the bottom (cf. the figures). Such a solution allows, for example, to simplify the assembly of the device.

[0078] Fig.14 and Fig.15 It is intended to illustrate a first possible way of mounting the preassembled detection unit 10, using the fixing element previously indicated by 6. Figure 5 As shown in the figure, in this embodiment, the fixing element 6 has an annular or tubular body having an outer wall 6a, which has a radially inwardly protruding flange 6b at the lower end to define a passage 6c, which has a diameter or cross-sectional size smaller than the maximum diameter or cross-sectional size of the sensitive element 3, thereby basically obtaining support for the sensitive element 3 or for the preassembled detection unit 10.

[0079] The resilient contact element 11 is mounted in the associated seat (see also Figure 6) so as to be in compression contact with the distal end portion 8b of the corresponding terminal 8; these portions 8b of the terminal may have holes or positioning protrusions for the upper ends of the elements 11 at positions corresponding to the seats for the elements 11 (in the example, since the contact elements are essentially in the form of helical springs, their upper ends are depicted in an originally protruding form in order to understand how this end will be elastically compressed during assembly to abut against the abutment portion 8b, see Fig.15 ). The preassembled unit 10, provided with the sealing element 12 on the outside, then rests from the bottom against the lower end of the portion 5b of the engagement portion 4, so that at least a portion of the unit 10 (here the circuit support 30a and preferably a portion of the positioning body 20) extends into the housing C'; as mentioned, the unambiguous positioning of the unit 10 is ensured by the coupling means, which are constituted by the seat 25 of the body 20 and the corresponding element 13 of the distal end portion 5b. This positioning ensures that the lower end of the contact element 11 is in contact with the corresponding pad 33 of the circuit support 30a ( Fig.10 ) electrical contact. In this assembled state, the upper part of the sealing element 12 rests on the end flat surface of the distal end portion 5b (as mentioned, for example in Figure 4 and Fig.15 In the corresponding details of FIG. 1 , the sealing element 12 is shown in a non-elastically compressed state).

[0080] The annular fixing element 6 is then placed from below on the distal end portion 5b provided with the detection unit 10. In various preferred embodiments, compensation and / or sealing means are provided between the fixing element 6 and the sensitive element 3, in particular designed to achieve axial compensation and / or sealing relative to the peripheral annular portion of the membrane of the sensitive element 3. In the illustrated case, a compensation and / or sealing ring 14 is provided for this purpose (see also Figure 5 ), preferably a flat annular element, such as Teflon, which is pre-inserted into the element 6 and which stands on the flange 6b.

[0081] It should be noted that element 14 may be absent or replaced by a technically equivalent element, since in any case the tightness is ensured by element 12. The presence of element 14 may be desirable to avoid possible damage to membrane 3a due to direct coupling with the metal of tubular element 6 (for example during its deformation, or due to possible thermal expansion).

[0082] The peripheral wall 6a of the fixing element 6 surrounds the sensitive element 3 and surrounds at least a part of the distal end portion 5b. The peripheral wall 6a is then fixed to the distal end portion 5b so that the flange 6b of the element 6 holds the detection unit 10 in place relative to the distal end portion 5b, with the sealing element 14 set therebetween. Fig.15 shown.

[0083] For the purpose of fixing, in various embodiments, the engaging portion 4 defines externally a seat 4b, at which the corresponding upper portion of the peripheral wall 6a of the element 6 is coupled. In various embodiments, the element 6 is made of a metallic material and the fastening relative to the seat 4b is accomplished by mechanical deformation, such as riveting or rolling; for this purpose, the seat 4b preferably has a surface that is generally flared upwards. Preferably, the operation of fixing the element 6 is performed while obtaining a slight compression of the element 14, in order to obtain or improve its tightness or elastic compensation function.

[0084] As in Fig.15 As can be seen in FIG. 1 , after the element 6 is fixed, the sealing element 12 mainly performs an axial seal between the upper surface of the sensitive element 3 and the aforementioned end flat surface of the portion 5 b. On the other hand, the ring 14 may also be able to seal between the flange 6 b of the element 6 and the peripheral part ( Fig.15 A substantially axial seal is achieved between the contact elements 12 and 14 to prevent possible penetration of fluid in this area. It should be understood that the installation of the unit 10 is substantially elastic due to the presence of the elements 12 and / or 14. The use of the elastic contact element 11 also facilitates this elastic installation.

[0085] In addition to ensuring the seal, the aforementioned elastic type of mounting also allows compensating possible mechanical stresses that could cause damage to the sensor, such as vibrations during use and / or mechanical stresses due to the mounting operations of the sensor in the user's device, these risks being greater in the case where the sensitive element is located at the distal end of the joint part that must be inserted into the pipe. If necessary, the elastic mounting also allows compensating possible different thermal expansions of the parts involved, these thermal expansions can be more pronounced in the region of the distal end of the joint part when directly exposed to the fluid.

[0086] In the assembled state, the upper end of one or more of the protrusions 24, 24' of the positioning body can abut against the corresponding surface 5a' of the distal end portion 5b (the corresponding surface can also be slightly spaced from the upper end to achieve the aforementioned elastic mounting, in which case it acts as a stop in the event of excessive stress).

[0087] Fig.16 and Fig.17 Schematically shows two possible installation configurations of the device 1, for example in a pipeline of a user device (such as a fuel cell system). In these figures, reference numeral 50 indicates a general fluid pipeline F whose pressure must be detected, and reference numeral 51 indicates a lateral or radial tubular passage of the pipeline 50, for the installation of the device 1.

[0088] exist Fig.16In the case of , the tubular passage 51 has a smaller axial extension (length) than the engagement portion 4 of the device 1 , but is nevertheless able to receive the external sealing element 7 . In this way, at least the distal end portion of the component 4 with the associated detection unit 10 protrudes inside the duct 50 . It will be understood that in this configuration, the membrane of the sensitive element is maximally exposed to the fluid, except for its peripheral annular area (which, however, is not subjected to deformation for the purpose of detection), which is covered and therefore protected by the flange 6 b of the fixing element and possible compensation and / or sealing elements 14 . In such a configuration, points where moisture could accumulate do not exist or are in any case limited, so that possible icing does not affect the correct operation of the device 1 .

[0089] Fig.17 A different mounting configuration is involved, in which the tubular passage 51 has a greater axial extension (length) than the engagement portion 4 of the device 1. In this case, the engagement portion 4 with the associated detection unit 10 is in a recessed (non-protruding) position relative to the pipe 50. However, even in this configuration, the same effect as described above is obtained, namely reducing the points where moisture present in the fluid F can accumulate.

[0090] Fig.16 and Fig.17 The assembly configuration can also be used in the case of the modified embodiment described below.

[0091] It should be noted that Fig.16 and Fig.17 In the assembled configuration, at least a portion of the sensitive element 3 or the detection unit 10 is protected relative to the tubular passage 51 , in particular by the annular element 6 .

[0092] Fig.18 A possible variant embodiment is shown in which the flange 6b of the element 6 is replaced by a plurality of retaining elements 6b' projecting radially inwards, that is to say, which are substantially L-shaped, but which still fulfil the functions described above for said flange 6b. The small size of the retaining elements 6b', i.e. the presence of free spaces between these elements 6b', reduces the area of ​​possible condensate stagnation at the membrane 3a and therefore further reduces the risk of possible ice formation on the membrane.

[0093] The fact that the unit 10 itself produces a preassembled and manipulable assembly makes it possible to provide various alternative configurations of corresponding fixing means.

[0094] Figure 19-21 The case where the unit 10 is glued to the distal end portion 5b of the joint portion 4 is illustrated. Fig. 20 and Fig.21As can be seen in , many of the concepts already explained above also apply to this case, with the difference that, preferably, in this case, the distal end portion 5b is configured such that there is a lower annular wall 5b" or tubular section, which is configured to also at least partially surround the sensitive element 3.

[0095] In this case, an annular layer of adhesive material 40 can be placed between the portion 5b and the relevant facing surface of the sensitive element 3 to ensure mechanical fixation and hermetic sealing. In this case, the elements 12 and 14 of the previous figures are therefore not essential. The fixing element or unit 10 is represented here by the adhesive material 40.

[0096] In various embodiments, the adhesive material 40 is elastic, also creating a sealing element that is substantially similar to the sealing element previously represented by 12 from a functional point of view, such as allowing elastic compensation if necessary, or even allowing minimal movement of the unit 10 relative to the end portion 5b.

[0097] Figure 22-Figure 24 The case of fixing the unit 10 to the distal end portion 5b of the engagement portion 4 by means of a fixing element 6' is illustrated, which has a structure similar to that of the previously described element 6 and thus has an annular body with a peripheral wall 6a and a lower flange 6b projecting radially inwards. Also in this case, the peripheral wall 6a is preferably shaped so as to surround at least a portion of the unit 10, in particular at least its sensitive element 3, and a portion of the distal end portion 5b.

[0098] In the illustrated case, the engaging portion 4 and the fixing element 6' are formed of plastic material and are fixed together, preferably welded or glued, at facing surfaces of the portion 4 and element 6, for example along an annular fixing path with the detection unit 10 interposed therebetween.

[0099] In this case, welding or gluing forms the mechanical fixing element and at the same time ensures a hermetic seal. Thus, additional elements, such as those previously indicated by 12 and 14, are not necessarily required, but they may be present.

[0100] Figure 25-27 Illustrate the following Figure 19-21 Another possible way of fixing the unit 10 to the distal end portion 5b of the engagement portion 4 is similar to the method of the embodiment of the present invention. Also in this case, the distal end portion 5b comprises a peripheral wall or a lower tubular section 5b″ which is designed to surround at least a part of the sensitive element 3. In addition, the portion 5b has an undercut 5c on the outside, at which a passage is defined that is in fluid communication with the interior of the cavity C′.

[0101] After the unit 10 is positioned relative to the lower end of part 5b and the corresponding cavity C', a large amount of fixing material 45 is poured or injected into the cavity through the hole 5d, which substance forms an electrically insulating fixing element, such as a sealing and gluing resin, which fills the gap between the inner surface of part 5b (i.e., cavity C') and a part of the detection unit 10.

[0102] Preferably, the fixing material 45 is introduced in such an amount that it creeps between the tubular section 5b″ and the peripheral surface of the sensitive element 3 and that at least a portion of the positioning body 20 and the circuit support 30a are embedded in the material 45, for example, as in Fig. 27 In this case as well, the polymerization of the material 45 ensures mechanical fixing and gas-tight sealing without the need for additional sealing elements.

[0103] In various embodiments, the pressure-sensitive element 3 may be equipped with a sensor device for detecting the temperature of the fluid F. Temperature detection may be useful, for example, for compensating the pressure measurement or for performing corrective actions in case the fluid tends to assume a potentially harmful temperature (e.g., a heating element may be activated in case an excessive drop in temperature is detected, which could potentially lead to ice formation with possible moisture accumulation).

[0104] Figure 28-Figure 29 This involves the case where a temperature sensor 60, such as a positive temperature coefficient (PTC) thermistor, is arranged on the inner side of the membrane 3a. The sensor 60 can advantageously be realized by a thick film deposition process, for example using screen printing technology, which is also used to define Fig. 9 The detection elements 3d and the corresponding conductive tracks are also located on the inner side of the membrane 3a. Fig.28 It can be seen that the thickness of the temperature sensor 60 is less than the height of the chamber 3f defined between the substrate 3b and the membrane 3a and that, therefore, the temperature sensor does not hinder the elastic deformation of the membrane. In this case, on the inner side of the membrane 3a there will be a conductive track for transmitting the signal from the sensor 60, which is connected in a manner known per se to at least two of the pins 3e.

[0105] The implementation of the temperature sensor 60 obtained by the process shown is particularly convenient, since the same process can be used both to obtain the temperature sensor and to obtain the element 3d ( Fig. 9 ), and is effective because the sensor 60 is in direct contact with the membrane 3a, the outer side of which is directly exposed to the fluid (see, for example, Figure 16-Figure 17). In this regard it should be noted that the membrane 3a is directly exposed to the fluid flow and is directly surrounded by it; the membrane 3a is thin and preferably formed of a material characterized by good thermal conductivity (for example a ceramic material such as alumina): in this way the membrane 3a is able to quickly transmit temperature changes to the sensor 60, even if the sensor is located in a protected position on the internal side of the same membrane.

[0106] Incidentally, the temperature sensor can be obtained in different ways, for example as in Figure 30-Figure 31 . Also in this solution, the temperature sensor 60 is located on the inner side of the membrane 3a, but in this case it is constituted by a surface mounted component (or SMD). In this case, the thickness of the sensor 60 can be greater than the height of the chamber 3f, so that in the substrate 3b of the sensitive element 3, a space or recess 61 can be defined to be able to accommodate the upper part of the sensor 60, so as not to hinder the bending of the membrane 3a.

[0107] In various embodiments, the pressure-sensitive element 3 may be equipped with a heating device in order to prevent or eliminate possible freezing of moisture residues thereon in the case of a gaseous fluid, or to prevent or eliminate possible freezing of liquid thereon in the case of a liquid fluid.

[0108] Fig.32 A case is shown in which a heater 62 (e.g. a screen-printed resistor) is arranged on the inner side of the membrane 3a. Also in this case, if necessary, the substrate 3b can be provided with a space or recess 63 intended to allow the upper part of the heater 62 to be accommodated so as not to hinder the bending of the membrane 3a. Also in this case, a conductive track for powering the heater 62 will be provided on the inner side of the membrane 3a, which is connected to at least two of the pins 3e. Also in this case, the membrane 3a is thin and is preferably formed of a material characterized by good thermal conductivity (e.g. the aforementioned aluminum oxide), so that the membrane itself can quickly transfer the heat generated by means of the heater 62 and avoid or solve any icing problems. The operation of the heater 62 can be managed by the internal electronics of the device 1, or by external electronics to which the device 1 is connected via its connector (2a, 8).

[0109] As will be seen, in a possible variant embodiment, the control circuit 30 may be obtained directly on the upper face of the substrate 3 b , in which case the circuit support 30 a and the body 20 may not be necessary.

[0110] The device 1 is fixed to a pipe 50 into which the fluid to be tested flows. Figure 16 to Figure 17) can be achieved by using various fixing means (such as screws or similar threaded members), or by using a bayonet connection, or by welding, or by a thread at least a portion of the outer surface of the engaging portion 4: the case of being achieved by a thread at least a portion of the outer surface of the engaging portion is Fig.33 , wherein the aforementioned thread is represented by 4C.

[0111] A threaded connection of the type shown can also be used to avoid the presence of an external sealing element 7, that is, the same thread 4c fulfills the function of a sealing element. For such a case, the thread 4c can extend to a greater extent on the outside of the engagement portion 4, i.e. as far as the region from which the distal end portion 5b extends. Fig.34 Example in.

[0112] Fig.35 Another fixing situation is schematically shown, in which the external sealing element 7 is not necessarily present. In this example, the body 2 (i.e. its engagement portion 4) is fixed relative to the passage 51 of the pipe 50 by means of fixing means, which includes a fixing material 65, such as a resin. In such a case, the resin performs a mechanical fastening function and a sealing function.

[0113] The outer sealing element 7 (when provided) may have a circular cross section, as in the previous examples, or have a quadrilateral cross section, or be a lip seal ring.

[0114] Regardless of the design type, with reference to the direction in which the distal end portion 5b or the coupling portion 4 is inserted into the corresponding passage (such as the passage 51 of the pipe 50), the sealing element 7 (or a device replacing it) is preferably located between the two ends 5a and 5b of the coupling portion 4, upstream of the detection unit 10 (and therefore upstream of the sensitive element 3) and upstream of the device for fixing the unit 10 to the distal end portion 5b.

[0115] From the description given, the features of the invention and its advantages are clear.

[0116] The proposed solution is simple, economical and reliable in construction, since the detection unit, which comprises at least the pressure-sensitive element of the device and the control electronics, can be preassembled, in particular with the help of a positioning body, and then easily and quickly mounted on the supporting body, even in a fully automatic manner. The preferred design allowing the use of elastic contact elements further simplifies the assembly of the device and reduces the likelihood of stresses with respect to the detection unit. The installation of the device in the working position is also simplified, given that the engagement portion supporting the detection unit can simply be inserted into the corresponding passage, wherein the sensitive element is in any case protected from the periphery and does not come into contact with the surface of said passage, without the risk of possible mechanical stresses on the detection unit.

[0117] It is clear that a person skilled in the art may make several modifications to the pressure sensor device described as an example without departing from the scope of the invention as defined by the appended claims.

[0118] A surface mounted temperature sensor (or SMD) may possibly be arranged on the outer side of the membrane 3a, with a possible protective layer (for example of glass type). Similarly, a temperature sensor, for example of PTC type, may be screen printed on the outer side of the membrane 3a, with a corresponding protective layer (for example of glass type). Figure 36-Figure 38 , in which the above-mentioned temperature sensor on the outer side of the membrane 3 is indicated by 60 ′ and the above-mentioned protective layer is indicated by 66. In an embodiment of this type, the sensitive element 3 will be provided in a known manner with suitable connection elements (such as conductive tracks and / or metallized holes) for transmitting the corresponding signals to the two pins 3 e. Obviously, this type of variant can be used in all the embodiments described herein.

[0119] Figure 39-41 Alternatively, it concerns the case of a sensitive element 3 in which the membrane 3a has a smaller diameter (or cross-sectional dimensions) than the diameter of the corresponding substrate 3b, without compromising the fixing of the membrane to the corresponding substrate (in particular by means of the material layer 3c), and the annular sealing and / or compensating element 14 is placed between the flange 6b of the element 6 and an annular zone of the lower face of the substrate 3b, which is radially outside the membrane 3a. In this case, the membrane 3a preferably has a smaller diameter (or cross-sectional dimensions) than the diameter of the passage 6c defined by the same flange, although this is not an essential feature. This type of embodiment makes it possible to prevent possible assembly or installation stresses or thermal deformations from being transmitted to the membrane 3a.

[0120] As mentioned, the control circuit 30 can be obtained on the upper face of the substrate 3b of the sensitive element 3. In such embodiments, the functions of the previously described circuit support 30a and the positioning body 20 can be obtained by such a substrate 3b. In these embodiments, therefore, the preassembled detection unit comprises a sensitive element directly supporting the control circuit, i.e. without the intervention of the positioning body 20.

[0121] Examples of this type are Fig.42 and Fig.43 , wherein the detection unit is indicated as a whole by 10' and the sensitive element is indicated as a whole by 3'. In such embodiments, the substrate 3b may include at least two different parts, and in particular the diameter or cross-sectional dimensions of the upper part are smaller than the diameter or cross-sectional dimensions of the lower part. In the non-limiting example shown, the substrate 3b includes a lower part 3b' having a diameter substantially similar to the diameter of the membrane 3a and an upper part 3b' of reduced diameter (without prejudice to Figure 40-41 Possibility of variations of the type shown).

[0122] On the upper surface of the substrate 3b, here on the upper face of the portion 3b″, a control circuit 30 is obtained, which has corresponding elements (such as those previously indicated by 31, 31a, 33) and corresponding conductive connection tracks not shown (as an alternative, the electronics of the device or the control circuit can be located partly on the circuit support 30 and partly on the upper face of the portion 3b″ of the substrate 3b). In this case, the upper parts of the pins 3e of the sensitive element 3 only slightly protrude from the substrate 3b and / or can be replaced by pads, from which the corresponding conductive tracks of the circuit 30 extend.

[0123] as Fig.43 As shown, the upper portion 3b" of the substrate is shaped so as to be at least partially accommodated in the cavity C' of the distal end portion 5b and to allow the positioning of the axial sealing element 12. In addition, the portion 3b" can be configured so that one or more areas of its upper face can abut against one or more corresponding axial positioning surfaces 5a', of the type already mentioned above.

[0124] Advantageously, the body of the base plate 3b, for example at the peripheral face of its upper portion 3b″, may also define a seat or recess, here indicated by 25 ′, for coupling with a corresponding element 13 of the distal end portion 5b , so as to identify the unambiguous positioning of the unit 10 ′.

[0125] for Figure 42-Figure 43 In the embodiment of the present invention, where desired, a printed circuit board 30a for the circuit 30 may be provided in any manner, such as glued or otherwise constrained on the upper face of the substrate 3'.

[0126] It should be understood that reference Figure 42-Figure 43 The illustrated concepts can also be used in all the embodiments described previously.

Claims

1. A pressure sensor device for a fluid, in particular a gaseous fluid, comprising a support body (2) and a detection arrangement associated with the support body (2), in, The detection arrangement comprises: a pressure-sensitive element (3), the pressure-sensitive element having a detection membrane (3a); and a circuit arrangement (3e, 8, 11, 30), the circuit arrangement comprising a control circuit (30) and an electrical connection element (3e), the control circuit having a printed circuit support (30a), the electrical connection element electrically connecting the pressure-sensitive element (3) to the printed circuit support (30a), The pressure-sensitive element (3) is associated with the support body (2) so that a majority of the detection film (3a) is directly exposed to the outside of the support body (2) for contact with the fluid (F). Features: The support body (2) has a joint portion (4), which is particularly configured to be inserted into a passage (51) of a conduit (50) for the fluid, and the joint portion (4) has a distal end portion (5b), and the pressure-sensitive element (3) is constrained at the distal end portion; The printed circuit support (30a) is associated with a positioning body (20), the positioning body is associated with the pressure-sensitive element (3), the electrical connection element (3e) constrains the printed circuit support (30a) to the pressure-sensitive element (3), the positioning body (20) is at least partially set between the printed circuit support and the pressure-sensitive element to form a detection unit (10), And wherein the detection unit (10) is fixed to the distal end portion (5b) of the engagement portion (4) by means of at least one fixing element (6; 6'; 40, 45).

2. The device according to claim 1, wherein: The distal end portion (5b) of the engagement portion (4) is shaped to accommodate at least one portion of the detection unit (10) internally, the at least one portion including at least a portion of the printed circuit support (30a) and / or the positioning body (20).

3. The device according to claim 1 or claim 2, wherein: The distal end portion (5b) of the engagement portion (4) defines one or more rest or axial locating surfaces (5a) for at least one of the locating body (20) and the pressure sensitive element (3).

4. The device according to any one of claims 1 to 3, wherein: The detection arrangement comprises an electrical connection terminal (8) having a respective end portion (8b) extending within the engagement portion (4), and wherein a resilient contact element (11) is interposed (11) between the end portion (8b) of the electrical connection terminal (8) and the printed circuit support (30a).

5. The device according to any one of claims 1 to 4, wherein: the at least one fixing element (6, 6') comprises an annular body having a peripheral wall (6a) which at least partially surrounds the pressure-sensitive element (3) and which surrounds at least a section of a distal end portion (5b) of the engagement portion (4), - the peripheral wall (6a) has at its lower end a radially inwardly projecting flange (6b) and one of a plurality of radially inwardly projecting retaining elements (6b'), and - the peripheral wall (6a) is fixed to the distal end portion (5b) of the engagement portion (4) so ​​that the flange (6) or the plurality of retaining elements (6b') holds the detection unit (10) in position relative to the distal end portion (5b) of the engagement portion (4), with the compensating and / or sealing element (14) being able to intervene therebetween, Among them, preferably: - the annular body of the at least one fixing element (6) is made of metal material and the engagement portion (4) externally defines a seat (4b) to which the corresponding upper portion of the peripheral wall (6a) is coupled, in particular by mechanical deformation, or The annular body of the at least one fixing element (6) is made of plastic material and the peripheral wall (6a) is fixed or welded to a section of the distal end portion (5b) of the engagement portion (4).

6. The device according to any one of claims 1 to 4, wherein: The distal end portion (5b) of the engagement portion (4) is shaped to accommodate a portion of the detection unit (10) therein, the portion of the detection unit also including at least a portion of the pressure-sensitive element (3).

7. The device according to claim 6, wherein: The distal end portion (5b) of the engagement portion (4) has a tubular section (5b) which at least partially surrounds the peripheral surface of the pressure-sensitive element (3).

8. The device according to claim 6 or claim 7, wherein: A fixing material (40; 45) is set between at least one of the peripheral surface and the upper surface of the pressure-sensitive element (3) and the corresponding surface of the distal end portion (5b) of the engaging portion (4), and the fixing material forms at least one fixing element.

9. The device according to any one of claims 1 to 8, wherein: The joining portion (4) is externally provided with a sealing part (7; 4c; 65), and the sealing part is particularly located at a certain position of the joining portion (4) relative to the distal end portion (5b) of the joining portion (4), and the position is located upstream of the detection unit (10), and preferably also upstream of the at least one fixing element (6; 6'; 40; 45).

10. The device according to any one of claims 1 to 9, wherein: The support body (2) is provided with a device (4c, 65) for fixing in an appropriate position, and relative to the distal end portion (5b) of the transfer portion (4), the device for fixing is particularly located at a certain position of the coupling portion (4), which is located upstream of the detection unit (10), and preferably also upstream of the at least one fixing element (6; 6'; 40; 45).

11. The device according to any one of claims 1 to 10, wherein: The positioning body (20) and the distal end portion (5b) of the engaging portion (4) have corresponding connectable elements (13, 25), which are configured to identify a unique installation position of the detection unit (10) relative to the distal end portion (5b) of the engaging portion (4).

12. The device according to any one of claims 1 to 11, wherein: The positioning body (20) and the printed circuit support (30a) have corresponding coupling elements (24, 34) configured to identify the installation position of the printed circuit support (30a) on the positioning body (20).

13. The device according to any one of claims 1 to 12, comprising at least one axial sealing ring (12) arranged between a distal end portion (5b) of the engagement portion (4) and the detection unit (10).

14. The device according to any one of claims 1 to 13, wherein: At least one of the temperature sensor (60) and the heating resistor (62) is associated with the detection membrane (3a), in particular with the inner side of the detection membrane, and / or wherein the pressure-sensitive element (3') comprises a substrate (3b), the detection membrane (3a) is fixed to the substrate by means of a fixing material (3c), and the circuit support and the positioning body are obtained through the substrate (3b).

15. A pressure sensor device for a fluid, in particular a gaseous fluid, comprising a support body (2) and a detection arrangement associated with the support body (2), in, The detection arrangement comprises: a pressure-sensitive element (3; 3') having a detection membrane (3a); and a circuit arrangement (3e, 8, 11, 30) comprising a control circuit (30) and a connection element for electrically connecting the pressure-sensitive element (3; 3') to the control circuit (30), characterized in that the pressure-sensitive element (3; 3') and / or the control circuit (30) are configured to be fixed to a distal end portion (5b) of a joint portion (4) of the support body (2), preferably by means of a fixing and protection element (6) or by means of a distal end portion (5b) shaped for this purpose, wherein preferably: The pressure-sensitive element (3') comprises a substrate (3b), the detection film (3a) is fixed to the substrate via a fixing material (3c), and - the control circuit (30) is formed on the upper surface of the substrate (3b) of the pressure-sensitive element (3') and / or on a printed circuit support, which is constrained on the upper surface of the substrate (3b) to form a detection unit (10).

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