Valve comprising a compensating element
Patent Information
- Application Number
- ES2021719247T
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-03-11
- Publication Date
- 2026-09-14
- Estimated Expiration
- 2041-03-11
Smart Images
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Abstract
Description
Valve comprising a compensating element Field of invention The present invention relates to a valve for controlling the flow of a fluid, and has been developed with special reference to an electrically operated valve, which is to be mounted in a fluid circuit or fluid system or fluid device, in particular of a motor vehicle or household appliance. Previous technique Valves for controlling fluid flow have been known and marketed for some time, for use in a wide range of sectors. It is also common to find valves that incorporate a compensating element to offset potential increases in the volume and / or pressure of the controlled fluid, thus preventing structural damage that could compromise the valve's operation. Such solutions are typically adopted in hydraulic devices and fluid systems that operate for extended periods in low ambient temperatures, such as motor vehicles, outdoor appliances (e.g., on a balcony), or irrigation systems. For example, US patent 7,891,370 B1 describes a pilot valve for irrigators having a body made of plastic material, provided with a housing for the installation of a solenoid having a core with an opening / closing member made of elastomer, which is capable of cooperating with a valve seat. The valve is provided with a tubular compensating element made of elastomeric material, and therefore elastically deformable or compressible, to prevent possible structural damage resulting from freezing of the controlled fluid. This compensating element is mounted in a housing intentionally provided in the valve body, which is separate from the chamber where the valve seat is located, but in any case is in fluid communication with said chamber.In this way, a possible increase in the volume of the fluid (typically water) due to its freezing can be compensated within the valve body thanks to an elastic compression of the compensation element. The solution described in the referenced document, while effective, is relatively complicated and cumbersome, as well as costly and impractical. Therefore, there is a need for valves to control fluid flow that are free from such disadvantages. US patent 8267375 B1 discloses a cartridge valve and valve manifold assembly where the valve manifold has at least one valve receptacle for receiving and seating a cartridge valve without threading. The cartridge valve comprises a sleeve sized to fit tightly in a receptacle seat of the manifold, the sleeve having a distal end seating a sealing element such as an O-ring around it, to seal the valve sleeve to the receptacle seat of the manifold. US patent 7278625 B2 discloses a valve device for dosing a urea-water solution for the aftertreatment of exhaust gases from internal combustion engines, containing elements that flex or compress under high pressure so that the volume of the working chamber can change to limit the high pressures, which arise in case of a phase change of the fluid to be dosed, to a non-damaging intensity. Object and summary of the invention In view of the foregoing, the present invention is intended to provide a valve for controlling the flow of a fluid that has structural characteristics such that it allows for easier and more efficient use, even compared to the known solution described above. Within this general framework, according to one aspect thereof, an objective of the invention is to provide such a valve, comprising a suitable compensating element to prevent potential damage resulting from an increase in fluid volume and / or pressure, and having a simple, less expensive, and more compact structure. According to another aspect, an objective of the invention is to provide a valve in which the risks of malfunction due to inefficient cooperation between the means for closing the fluid and a corresponding valve seat are avoided. According to yet another aspect, an objective of the invention is to provide a valve that is simple and inexpensive to produce.One or more of the aforementioned objectives, and other objectives that will become clear later, are achieved according to the present invention by means of a valve for controlling the flow of a fluid and by means of a corresponding compensating element having the characteristics mentioned in the appended claims. The claims form an integral part of the technical instruction provided herein in connection with the invention. Brief description of the drawings Other objectives, features, and advantages of the invention will become clear from the following detailed description, with reference to the accompanying drawings, which are provided only by way of non-limiting example and in which: Figure 1 is a schematic perspective view of a valve according to possible embodiments of the invention; Figure 2 is a schematic exploded view of a valve according to possible embodiments of the invention; Figures 3 and 4 are schematic cross-sectional views of a valve according to possible embodiments of the invention, where the corresponding means for closing the fluid are in a closed position and an open position, respectively; Figures 5 and 6 are schematic sectioned perspective views of a valve according to possible embodiments of the invention, where the means for closing the fluid are in a closed position; Figures 7 and 8 are schematic perspective views of a compensation element according to possible embodiments of the invention; Figures 9 and 10 are schematic sectioned perspective views of a part made of molded plastic material of a valve body according to possible embodiments of the invention, with a corresponding compensation element not yet mounted and mounted, respectively; Figure 11 is a cross-sectional view similar to that of Figure 4, intended to exemplify the operation of a compensation element provided according to the invention; Figures 12-14 are schematic cross-sectional views of parts of a valve, intended to exemplify possible deformations suffered by a tubular portion of a valve body due to the freezing of the controlled fluid, in the absence of a compensating element; Figure 15 is a schematic view, similar to those in Figures 12-14, of a valve according to embodiments of the invention; and Figure 16 is a schematic cross-sectional view similar to that in Figure 3, with respect to a possible embodiment variant. Description of embodiments of the invention Reference to "an embodiment" within this description is intended to indicate that a particular configuration, structure, or feature described in connection with the embodiment is comprised in at least one embodiment. Therefore, phrases such as "in one embodiment," "in several embodiments," and the like, which may appear at various points in this description, do not necessarily refer to one and the same embodiment. Furthermore, particular configurations, structures, or features defined within this description may be combined in any suitable manner in one or more embodiments, even different from those depicted. Reference numbers and spatial references (such as "top," "bottom," "above," "below," etc.) used herein are provided for convenience only and therefore do not define the scope of protection or the extent of the embodiments.In this description and in the appended claims, the generic term "material" shall be understood to include mixtures, compositions, or combinations of several different materials (for example, multilayer structures or composite materials). The same reference numbers are used in the figures to designate elements that are similar or technically equivalent to each other. It should be noted that, in the attached figures, some elastically deformable elements, such as joints and an opening / closing member, are illustrated in some figures (such as Figures 3-6, 11 and 16) in an undeformed condition, for representational purposes. With initial reference to Figure 1, designated in its entirety as 1, it is a valve for controlling the flow of a fluid according to possible embodiments of the present invention. In several embodiments, valve 1 is an electrically operated valve, in particular a solenoid valve. The valve 1 comprises a valve body 2, at least part of which is made of molded plastic material, such as a thermoplastic material, for example polyamide, polypropylene, polyphenylene sulfide, or polyphthalamide. The plastic material may possibly be filled, for example, with a reinforcing material such as fiberglass. In the embodiment depicted in the figures, the valve body 2 is entirely made of molded plastic material, but this feature should not be understood in a limiting sense, since in other embodiments the valve body 2 may comprise, in addition to the part made of molded plastic material, one or more portions made of one or more different materials, for example, metal. With reference also to figures 2-4, in several embodiments the plastic material of the valve body 2 is overmolded onto a metal insert, here in the form of a plate 3. In other embodiments, the insert or plate 3 may be mounted or coupled to the body 2. Preferably, the metal plate 3 has a substantially square cross-section, but this feature is not limiting insofar as in other embodiments (not illustrated) the plate 3 may have a different cross-section, for example, a rectangular or circular cross-section. In several embodiments, such as the one shown in Figures 2-4, the plate 3 is partially embedded in the plastic material at a first end region 2' of the valve body 2. At least a portion of the insert plate 3 that is not embedded in the plastic material of the valve body 2, i.e., that protrudes from it, can be configured as a polarizing element for the purpose of installing the valve in a different position. The insert or plate 3 can, if necessary, serve other purposes, for example, providing a fastening element, such as a flange with screw holes, or with reliefs belonging to a bayonet coupling. As will be seen, in several embodiments, plate 3 is part of an electromagnetic yoke of a valve 1 activation coil. The provision of an insert, such as plate 3, is also particularly advantageous for the purpose of attaching an electrically driven assembly, described below, to the valve body 2. For this purpose, plate 3 preferably has one or more grooves 4 on one or more of its peripheral surfaces that project outwards from the material forming the valve body 2, the function of which will be explained later. In the illustrated embodiment, plate 3 has at least one groove 4 on each of its two opposite sides, but this feature should not be considered a limitation. With particular reference to Figure 2, the valve body 2 defines a seat 2a (see also Figures 9-10) to receive a corresponding annular sealing element 5, such as an X-ring gasket, as exemplified, or a gasket with flat surfaces (e.g., with a square or rectangular cross-section). In the illustrated example, the valve seat 2a is located in the first end region 2' of the valve body 2, in the portion that projects axially beyond the plate 3, i.e., at a proximal end of the valve body 2. Preferably, the annular element 5 and the seat 2a have a substantially circular shape. However, it should be understood that in other (not illustrated) embodiments, the seat 2a and the annular element 5 may be absent or may have different shapes and dimensions than those illustrated in Figure 2. As can be seen, in particular, in Figures 3-4, the valve body 2 comprises a fluid passage chamber, designated by 6, defined within the part made of molded plastic material, which is delimited by an approximately cylindrical peripheral wall 2b. The peripheral wall 2b has an internal surface 6' that peripherally delimits the chamber 6. The chamber 6 comprises at least one fluid inlet and at least one fluid outlet. In the embodiment illustrated in the figures, the chamber 6 comprises only one inlet 6a and only one outlet 6b, the mutual arrangement of which will be discussed in more detail later in this description. However, in other (not illustrated) embodiments, the chamber 6 may comprise two or more fluid inlets and / or two or more fluid outlets. In several embodiments, the inlet 6a is defined at an axial end of the valve body 2, opposite an opening circumscribed by the seat 2a for the seal 5, while the outlet 6b is defined in the peripheral wall 2b. Defined within the fluid passage chamber 6 is a valve seat, designated by 7 in Figure 3, with which closing means 8-9 cooperate to shut off the fluid. These closing means are movable relative to the valve seat 7 to control the fluid flow. In the preferred embodiment, the closing means 8-9 are movable relative to the valve seat 7 between at least one closed position (visible in Figure 3), where the fluid cannot pass from the inlet 6a to the outlet 6b, and an open position, in particular a maximum open position (visible in Figure 4), where the fluid can pass from the inlet 6a to the outlet 6b, particularly at a maximum flow rate. In preferred embodiments, valve 1 is an open / closed type valve (normally closed or normally open), i.e., of the type where the closing means 8-9 are capable of assuming only the two open and closed positions mentioned. In other embodiments (not illustrated), however, the closing means 8-9 and the corresponding actuating assembly are configured such that the former can be displaced relative to the valve seat 7 between one or more intermediate positions with respect to the open and closed positions illustrated in Figures 3 and 4 to allow variable control of the fluid flow rate between the inlet 6a and the outlet 6b of chamber 6. In the preferred embodiment, the fluid shutoff means 8-9 comprise an opening / closing member 8 (or valve member), preferably made at least partly of an elastically deformable material, such as an elastomeric material. In the example shown, the opening / closing member 8 is configured essentially as a rubber element or tip, particularly substantially cylindrical, which is fixed to an axial end of a corresponding drive shaft, here constituted by the movable core 9 of a solenoid, as explained below. It should be understood that the opening / closing member 8 may have shapes and dimensions that vary from one embodiment to another, and also have a hardness that varies according to the application (e.g., a hardness between 50 and 80 ShA). Possibly, the opening / closing member 8 could be made of metal and / or have a shape designed to facilitate the aforementioned variable flow regulation. With particular reference to figures 4-6, when the opening / closing member 8 rests on the valve seat 7, in the closed position of valve 1 (figure 3), the circulation of fluid between the inlet 6a and the outlet 6b of chamber 6 is prevented. In embodiments of this type, the cross-sectional dimensions of the opening / closing member 8 are preferably larger than the cross-sectional dimensions of the valve seat 7. However, in other embodiments (not illustrated), the opening / closing member 8 may be configured to penetrate at least partially into a central passage of the valve seat 7, for example, when the opening / closing member is moved to the corresponding closed position and / or to intermediate adjustment positions. In these embodiments, the cross-sectional dimensions of the opening / closing member 8 may be at least partially smaller than the cross-sectional dimensions of the valve seat 7, and the depth of penetration into the valve seat may vary in different embodiments. Returning to Figure 2, and as already mentioned, in several embodiments the opening / closing member 8 is associated with the end of a drive shaft or core 9, preferably with a substantially circular cross-section. The core 9 can be displaced away from or near the valve seat 7 by means of a suitable drive assembly. In several embodiments, the valve drive assembly 1 comprises an electric actuator. In the preferred embodiment, as illustrated in the figures, the electric actuator is a solenoid, designated in its entirety as 10 in Figures 3 and 4, comprising a winding 11 that includes electrical wire wound in a coil 12. The coil 12 is axially traversed by a cavity (not shown) in which at least a portion of the core 9 is slidably engaged.The core 9 is made at least partly of a material that can be attracted by a magnetic field, i.e., a ferromagnetic material. The coil cavity 12 has a diameter slightly larger than that of the core 9 to allow the latter to slide. For this purpose, at least a portion of the chamber 6, within which the head portion of the core 9 slides, provided with the opening / closing member 8, has a circular cross-section, with a diameter substantially corresponding to that of the coil cavity 12. The solenoid 10 is preferably protected by a corresponding housing 13, preferably an overmolded housing made of electrically insulating material, preferably a molded plastic material, such as polyamide, or polypropylene, or polyphenylene sulfide, or polyphthalamide, possibly of a type containing filler material. The housing 13 preferably has a predominantly cylindrical outer shape (see Figure 2), and in several embodiments also defines a connector body, such as the one designated by 15, which projects in a radial direction. In other embodiments (not shown), the connector body may extend in the same axial direction as the activation coil (i.e., as the assembly consisting of coil 12 and winding 11). The housing 13 defines a seat at its upper part, designated 13a in Figure 2, to receive a corresponding annular element 14, preferably a gasket, such as an X-ring gasket or a gasket with flat surfaces. Preferably, the seat 13a and the corresponding annular element 14 have a substantially circular shape; however, it should be understood that in other embodiments (not illustrated), the seat 13a and the annular element 14 may be absent or may have different shapes and dimensions. In the embodiment illustrated in the figures, the solenoid 10 can be connected to an electrical power supply by means of the connector body 15, within which at least two electrical terminals 16 are arranged (only one of which is visible in several figures), one for each end of the electrical wire of the winding 11 wound around the coil 12. According to the known art, the passage of electric current through the winding 11 is capable of generating a magnetic field such that it causes the axial displacement of the core 9 within the cavity of the coil 12, preferably against the action of an elastic element, such as a spring.In this way, by electrically supplying the solenoid 10, the core 9 can be displaced from its rest position, for example, the closed position of the hydraulic conduit 6a, 6, 6b, where the opening / closing member 8 is held in a position corresponding to the valve seat 7, preferably pressed against it by the action of the aforementioned elastic element. The displacement of the core 9 thus obtained also causes the opening / closing member 8 to be displaced relative to the valve seat 7, thereby allowing fluid flow between the inlet 6a and the outlet 6b of chamber 6. With particular reference to Figures 2-6, in several embodiments the core 9 defines—at its end opposite the opening / closing member 8—a blind cavity 9a, preferably with a cylindrical section. The cavity 9a is arranged so that the first end 17' of a spring 17 rests on its bottom, while the opposite end 17" rests, instead, on a counter-core, designated collectively as 18. The counter-core 18, typically made of ferromagnetic material, has a portion 18' having a substantially circular cross-section, which must be fixedly inserted within a corresponding part of the coil cavity 12. In the example shown, the counter-core 18 further has a flared head portion, designated 18", which preferably has larger perimeter dimensions than the cavity through the coil 12. Preferably, as partially seen in particular in Figure 2, a seat or shoulder 18a is defined in the transition area between the portions 18' and 18" of the counter-core 18 for positioning an annular sealing element 20, such as a washer-type gasket.Preferably, in addition, defined on the peripheral surface of portion 18' are teeth or reliefs 18b, which must cooperate mechanically with the surface defining the axial cavity of the coil (see, for example, figures 3-4) and basically perform the function of a wedge to block, by mechanical interference, portion 18' of the opposing core 18 within coil 12. In the illustrated embodiment, portion 18' of the opposing core 18 has no cavity in the contact surface with the second end 17" of the spring 17: however, in other (not illustrated) embodiments, the second end 17" of the spring 17 could rest on the bottom of a blind cavity defined in said portion 18', in a position opposite to the head portion 18". The actuator assembly, including the solenoid 10 and the housing 13, is fixed in region 2' of the valve body 2 such that the core head region 9, with the opening / closing member 8 associated with it, projects from the assembly itself into the chamber 6, as can be clearly seen in Figures 3-4. In this way, the sealing means represented by the gasket 5 operates between the front of the assembly 10-13 and the valve body 2. As can be seen, in particular, in Figures 1-6, in several embodiments, the housing 13, with the solenoid 10 inside, is mechanically secured to the valve body 2 by means of a metal armature 21, in particular made of ferromagnetic material, here substantially U-shaped, i.e., with two generally parallel vertical walls 21a connected to each other by a transverse part 21b. At the ends of the walls 21a opposite wall 21b, appendages 22 can be provided, configured to engage with the aforementioned slots 4 of plate 3 (see figure 2). For example, a section of each appendage 22 can be engaged in a respective slot 4, and a terminal section of the same appendage 22 can be bent so as to engage plate 3 and armature 21 together, thus completing an electromagnetic yoke for solenoid 10: in the example, then, the assembly consisting of solenoid 10 and cover 13 is packed between valve body 2 and armature 21, with gasket 5 positioned in between. In several embodiments, such as the one shown, the armature 21 has an opening 21' in its cross-wall 21b to allow the penetration of the portion 18' of the opposing core 18 into the cavity of the coil 12, up to the end of the mechanical travel determined by the head portion 18", with the possible sealing element 20 resting on an internal shoulder of the cavity of the coil 12. Preferably, in the assembled configuration, the armature 21 and the opposing core 18 are in contact, for example, with mutual mechanical interference, i.e., coupled at the electromagnetic level. According to an important aspect, the valve body 2, made of plastic material, is molded to define a longitudinally extended tubular portion, which extends into the fluid passage chamber between the valve seat and one of the fluid inlets and the fluid outlet. Preferably, this tubular portion extends longitudinally or axially—between the valve seat and at least one of the fluid inlets and outlets—in the same direction of movement as the valve's opening / closing means. Again, preferably, the other fluid inlet and outlet are positioned laterally with respect to the aforementioned tubular portion. With reference to the illustrated example, and as can be seen, in particular, in figures 3-6 and 9-10, the valve body 2 defines the tubular portion designated by 23, which here extends between the valve seat 7 and the fluid inlet 6a, within the chamber 6, preferably substantially coaxial with respect to the peripheral cylindrical surface 6' of the chamber 6 itself. Preferably, the tubular portion is substantially cylindrical. In preferred embodiments of the invention, the average thickness of the tubular portion 23 is less than the average thickness of the wall 2b of the valve body 2 that peripherally delimits the chamber 6 for the passage of the fluid (which means an average between the minimum thickness and the maximum thickness of the wall of portion 23, on the one hand, and of wall 2b, on the other). A molded plastic material generally experiences what is called "shrinkage" after the molding stage. Shrinkage essentially consists of a dimensional reduction of the material that occurs after it cools and hardens. This shrinkage varies depending on the type of material (whose characteristics can differ to some extent from one raw material manufacturer to another) and other process parameters, which are also potentially subject to variations due to a wide range of factors (e.g., ambient and / or mold temperature, wear, molding rate, etc.).As a consequence of the contraction, in the case of a valve of the type considered here, dimensional variations of the valve seat could occur with respect to the optimal design dimensions, which in turn could be the origin of incorrect cooperation between the opening / closing member 8 and the valve seat 7, and consequently to incorrect control of the fluid flow through the valve. To overcome this drawback, in preferred embodiments of the invention, using the same molded plastic material as that of the valve body 2, a thin tubular portion 23 is defined, which defines the valve seat 7 at its end. As stated, the average thickness of the tubular wall is less than the average thickness of the wall 2b that peripherally delimits the chamber 6. For reference, the average wall thickness of the tubular portion 23 may be between 1.6 and 1.8 mm, while the average thickness of the peripheral wall 2b may be between 2.5 and 2.8 mm. Thus, since the shrinkage of the plastic material after the molding stage is substantially proportional to the thickness of the material itself, the tubular portion 23 will undergo very limited shrinkage, sufficient to ensure in any case the definition of a sufficiently precise valve seat 7, i.e., sufficient to not compromise its cooperation with the opening / closing member 8. Instead, the peripheral wall 2b of the valve body 2, which delimits the chamber 6, can be formed with the thickness considered most suitable in view of the operating pressure of the controlled fluid and the mechanical anchoring of the actuator assembly 10-13. As will be further appreciated, the valve seat 7 can also be defined directly by the tubular portion 23 itself; i.e., it is made as a single piece with the valve body 2, without the need for an additional element dedicated for this purpose, as, for example, in US patent 7,891.370 B2. As stated, preferably the port between the fluid inlet and the fluid outlet not defined by the tubular portion 23 is positioned laterally with respect to the latter. Consequently, with reference to the non-limiting example illustrated in the figures, where the tubular portion 23 extends between the valve seat 7 and the fluid inlet 6a, the fluid outlet 6b is defined on the valve body 2 laterally with respect to the tubular portion 23, on wall 2b. It should be noted that, in other embodiments, the port designated 6a in the figures could correspond to the fluid outlet, and the port designated 6b could correspond to the fluid inlet. In such embodiments, therefore, the tubular portion 23 extends between the valve seat 7 and the fluid outlet, and the fluid inlet is located laterally with respect to the tubular portion 23.In other embodiments, port 6b could also be arranged substantially parallel to port 6a; for this purpose, body portion 2 is suitably shaped. As mentioned, in the preferred embodiment shown in the figures, the tubular portion 23 has a substantially cylindrical shape, i.e., a circular cross-section. However, this characteristic should not be understood as limiting, as other cross-sectional shapes are possible, particularly with regard to the type of opening / closing member 8 used. According to one aspect of the invention, the valve 1 comprises a compensating element, designed to compensate for a possible increase in volume and / or pressure of the controlled fluid, which is mounted within the chamber 6. As can be seen, for example, in Figures 2 and 7-8, this compensating element, collectively designated as 25, comprises at least one compensating body 26 made of an elastically deformable and / or compressible material, for example, an elastomeric material. For example, the body 26 can be molded from a silicone material, such as a silicone elastomer, liquid silicone rubber (LSR), or fluorinated liquid silicone rubber (FLSR). Preferably, the compensating body 26 is made of an impermeable material to prevent any penetration of the fluid into it. For this purpose, the chosen material preferably has a closed-cell structure.The molded plastic material of the valve body 2 is in any case more rigid than the elastically deformable and / or compressible material of the compensation body 26. In the embodiment shown in the figures, the compensating element 25 consists entirely of a compensating body 26 made of deformable and / or compressible material. However, this feature should not be considered limiting, as in other (not illustrated) embodiments the compensating element 25 may include other parts, which may also be made of different materials. For example, the compensating element could include a core made of a relatively rigid material, fixed (e.g., overmolded) onto which a compensating body 26 is mounted. As can be seen, for example, in Figures 2-3, the body 26 of the compensating element 25 is configured as a separate component from the valve body 2, designed to be mounted on it. As can be seen, in particular, in Figures 9-10, the compensation body 26 is mounted inside the chamber 6 so that it surrounds at least partially the tubular portion 23. For this purpose, the compensation body 26 has a section with a peripheral wall 27 of substantially cylindrical shape. Preferably, the compensation element 25 has at least one peripheral surface that has a profile at least partly complementary to that of a peripheral surface of one of the chamber 6 and the tubular portion 23. For example, the outer surface of the peripheral wall 27 of the compensation body 26 may have a profile that is at least partly complementary to the surface 6' of the body 2 that peripherally delimits the chamber 6. In addition, or alternatively, the inner surface of the peripheral wall 27 may have a profile at least partly complementary to the outer surface of the tubular portion 23. In possible embodiments, on the other hand, the compensation element 25 is coupled, for example elastically, only to the tubular portion 23, leaving space (for example, an annular space) with respect to the surface 6' that laterally delimits the chamber 6. Alternatively, the compensation element 25 could be coupled to the peripheral surface 6' of the chamber 6 via reliefs or projections of the outer surface of the wall 27, these reliefs or projections possibly extending in the axial direction of the element 25. Preferably, the axial extension of the compensating body 26 is such that, when positioned within the chamber 6, its upper end is higher than the valve seat 7, as can be seen, for example, in Figure 3: in any case, since the body 26 is axially hollow, the opening / closing member 8 carried by the core 9 can, in any case, reach the valve seat 7. With reference, in particular, to figure 7, in several embodiments the compensating body 26 comprises at least one side passage 28 in its peripheral wall 27 to allow the passage of fluid between the valve seat 7 and the outlet 6b. Preferably, the side passage 28 comprises a recess extending from a first longitudinal end 31 of the wall 27. The shape and extent of passage 28 may vary from one embodiment to another. In the embodiment shown in the figures, the compensation body 26 comprises only one side passage 28. However, in other embodiments (not illustrated), two or more side passages 28 may be provided. This solution becomes necessary, for example, when the chamber 6 for the passage of the fluid comprises two or more outlets (or inlets) 6b. In the embodiment shown in the figures, the lateral passage 28 comprises a recess extending from a first longitudinal end 31. However, in other embodiments (not illustrated), the passage 28 could have some other form, for example, be constituted by an opening in the peripheral wall 27 or some other opening in the compensation body 26. In several embodiments, the valve body defines a polarizing or positioning element within the fluid passage chamber. This element must cooperate with a counter-polarizing or positioning element of the compensating element to ensure their correct relative angular positioning, for example, during the assembly stage. Preferably, this polarizing element is positioned laterally with respect to the tubular portion that defines the valve seat. For example, with particular reference to figures 4 and 9, a polarization element 30 is defined within chamber 6, here consisting substantially of a rib or relief on the peripheral surface 6' of chamber 6, which extends in a lateral position with respect to the tubular portion 23. On the other hand, as can be seen in Figure 8, the peripheral wall 27 of the compensation body defines a polarizing counter-element 29, prepared to receive the element 30. In the example, the polarizing counter-element 29 comprises a recess extending from the second longitudinal end 32 of the cylindrical wall 27 of the compensation body 26. Here too, the shape and extent of the recess may vary from one embodiment to another. In a preferred version, the opposite polarizing element or recess 29 has opposing inclined surfaces, designed to engage with surfaces of the polarizing element or relief 30, which are also preferably at least partially inclined in opposite directions. The inclination of these surfaces also facilitates autonomous polarization or centering during installation, particularly through slight autonomous rotations of the compensation body 26, until it is oriented in the predefined position. The presence of element 30 and the opposing element 29, in addition to simplifying the assembly operation of valve 1, prevents the rotation of the compensating body 26 with respect to the valve body 2, so that the side passage 28 is always in the optimal position to allow the passage of fluid between the valve seat 7 and the outlet (or inlet) 6b. In the embodiment shown in the figures, the compensation body 26 comprises only one polarizing buttress 29, but it is clear that in other (not illustrated) embodiments the body 26 could comprise two or more opposing elements 29, and within the chamber 6 there could be as many polarizing elements 30. Obviously, a reverse arrangement is also possible, i.e., with the chamber 6 including at least one seat or recess, and the compensation body 26 comprising as many corresponding reliefs that engage in said recess. In the embodiment shown in the figures, the side passage 28 and the opposing polarizing element 29 are defined at substantially opposite positions on the cylindrical wall 27 of the body 26.However, even this feature should not be understood in a limiting sense insofar as, in other (not illustrated) realizations, passage 28 and the opposing element 29 could be in different angular positions. In several preferred embodiments, at least one of the fluid passage chamber and the compensation element comprises coupling means arranged to maintain the compensation element in a substantially predetermined axial position within the fluid passage chamber. In several embodiments, the aforementioned coupling means comprise at least one relief or rib on the outer surface of the wall 27 of the body 26. In the embodiment depicted in the figures, such relief or rib, designated by 33 in Figures 7-8, extends over at least a portion of the circumference of the compensating body 26. The rib 33, which may therefore be annular in shape, is configured to elastically engage with the surface 6' of the valve body 2. In addition, or alternatively, the coupling means could be provided on the body 2, for example, in the form of one or more reliefs or seats defined on the surface 6', with which the compensating body 26 elastically engages, particularly on the outer surface of its wall 27. The coupling means mentioned can also be mutual coupling means, that is, provided to be coupled together. For example, in the non-limiting case exemplified in the figures, a seat 34 can be defined on the surface 6' of chamber 6 where the rib 33 can be coupled. In other embodiments (not illustrated), the compensating body 26 may comprise two or more peripheral ribs 33, and the chamber 6 could comprise as many corresponding seats 34. Obviously, a reverse arrangement is also possible, i.e., with the chamber 6 including one or more peripheral ribs, and the compensating body 26 possibly comprising as many corresponding seats as extend over at least a part of its circumference. In several embodiments, valve 1 is incorporated into a fluid circuit, system, or device, for example, a hydraulic or pneumatic one. As mentioned, such a circuit may belong, for example, to an irrigation system, or the device may be a household electrical appliance. Preferably, valve 1 is used in circuits, devices, or systems on board a vehicle, particularly a motor vehicle.For example, the valve that is the object of the invention can be advantageously used in circuits, systems, and devices for the control and / or supply of water (or aqueous solution) in a vehicle, such as a windshield or headlight washing system of a motor vehicle, or a system for washing sensors belonging to autonomous driving systems, such as video cameras and sensors of LIDAR (Light Detection and Ranging) systems, a system for the control and / or supply of a water-urea solution to an SCR (Selective Catalytic Reduction) system for the reduction of nitrogen oxides from the exhaust gases of an internal combustion engine, a system for water injection belonging to an ADI (Anti-Knock Injection) system. In what follows, a detailed description of the use of a preferred embodiment of the valve, as schematically represented in Figures 1-10, will be provided. It is understood that this description is intended solely to enable an understanding of the operating mechanism and is not intended in any way to limit the scope of protection defined by the appended claims. In the preferred embodiment shown in the figures, when valve 1 is in its rest position (i.e., with the actuator assembly 10-13 not electrically energized), the opening / closing member 8, carried by the core 9, is in a closed position relative to the valve seat 7, as illustrated in Figures 3 and 5-6, driven to this position by spring 17. In this condition, as mentioned, there is no fluid flow between the inlet 6a and the outlet 6b of chamber 6. When it is necessary to open valve 1, solenoid 10 is electrically energized. The solenoid 10 thus generates a magnetic field that exerts an attraction on the core 9, causing it to retract relative to the valve seat 7, and thereby compressing spring 17, as can be seen in Figure 4.As mentioned previously, plate 3, counterweight core 18, and armature 21 provide a stationary electromagnetic yoke for the actuating coil formed by winding 11 on coil 12. When the actuating coil is supplied, a magnetic attraction force is generated on the yoke, which the counterweight core 18 tends to concentrate on core 9, causing the latter to retract, according to a well-known technique. The displacement of core 9 causes a corresponding recession of the opening / closing member 8 relative to the valve seat 7, with fluid then free to circulate between the inlet 6a and outlet 6b of chamber 6. Subsequently, the interruption of the electrical supply to solenoid 10 causes the magnetic field to cease, and the elastic reaction of spring 17 returns core 9 to the original position shown in Figure 3, with the opening / closing member 8 once again closing the valve seat 7. It is possible that, when the opening / closing member 8 is in the closed position, residual fluid may remain inside chamber 6. This risk also occurs when the hydraulic system into which the valve is inserted is subjected to draining operations, during which only the inlet 6a and the interior of the tubular portion 23 might be drained, while fluid would remain in chamber 6. Should this residual fluid freeze, the resulting increase in volume could cause considerable recoil on the opening / closing member 8 and the core 9, and therefore on the opposing core 18 and the entire actuator assembly 10-13. This thrust could be strong enough to compromise the fixing and / or sealing between the valve body 2 and the actuator assembly 10-13.The presence of the compensation body 26 within chamber 6 allows limiting the amount of residual fluid that can remain within chamber 6; at the same time, the ability of body 26 to be compressed allows compensating for the increase in fluid volume. Figure 11 illustrates a case where the hydraulic system, including valve 1, is not subject to draining operations. Therefore, fluid F, subject to freezing, is present within chamber 6 and both upstream and downstream of it. A comparison of Figures 4 and 11 shows how the increase in the volume of fluid F causes a modest recoil of core 9, comparable to what occurs under normal operating conditions when solenoid 10 is electrically energized. This is enabled by the prevailing axial compression of body 26, as highlighted in Figure 11, which allows for significant compensation of the increase in the volume of fluid F. As mentioned, Figure 11 refers to a case where the fluid remains within the hydraulic circuit where valve 1 is inserted, i.e., upstream and downstream of it. In applications of this type, the increase in the volume of residual fluid within the tubular portion 23 is substantially compensated by the increase in the volume of residual fluid within chamber 6 and outlet 6b, so that no significant deformation of the tubular portion itself occurs. In other applications, however, the hydraulic circuit or device where valve 1 is inserted may be of the type where the branches of the circuit upstream and downstream of the valve itself are drained after use, as mentioned previously. For example, in some hydraulic systems, such as certain SCR systems, draining passages are provided precisely to prevent or at least mitigate risks related to potential freezing. However, this does not rule out the possibility that residual fluid may remain within chamber 6. In the case of applications of this type, there is no liquid present within the tubular portion 23, which is present in chamber 6. The increase in the volume of the residual liquid in chamber 6 can cause significant compression of the tubular portion 23 in a radial direction, and therefore, equally significant deformations of portion 23, particularly considering its small thickness. Figures 12-14 show situations of this type in the case of valves without a compensating body 26 inside chamber 6. From these figures it can be observed how the increase in the volume of the fluid F causes considerable deformations of portion 23, which in the limit can cause permanent failures or deformations of this, in such a way that the correct cooperation between the opening / closing member 8 and the valve seat 7 is jeopardized. Figures 12-14 illustrate how the increase in the volume of the frozen fluid causes radial areas of deformation in the tubular portion 23, extending inward. This deformation can involve substantially the entire portion or only an intermediate, lower, or upper section, possibly also involving the valve seat 7. Such deformations can occasionally alter the flow paths for the fluid or affect the sealing area of the valve seat 7, or even cause points of failure in the tubular portion 23. The presence of the compensating body 26, as illustrated in Figure 15, helps prevent such risks. The body 26, mounted around the tubular portion 23, reduces the volume that can be occupied by the residual liquid. In the event of freezing of the residual liquid F, the resulting increase in volume is compensated for by the compressibility of body 26, preventing radial stress on the tubular portion 23. As is clear from the above description, the valve that is the object of the present invention achieves multiple advantages compared to the solutions available in the state of the art. First, the valve seat 7 is defined by a tubular portion 23 made from a single piece with the molded plastic portion of the valve body 2. This solution eliminates the need for additional components specifically designed to serve as the valve seat, resulting in a valve with simpler and more precise structural characteristics than those known in the art. Furthermore, the thinness of the tubular portion 23 minimizes the risk of shrinkage of the molded plastic material that could compromise the accuracy of the valve seat 7 and, consequently, the efficient interaction between the fluid sealing mechanism and the valve seat.Furthermore, the compressible or deformable body 26 of the compensating element 25 is advantageously located within the fluid passage chamber 6, around the tubular portion 23, without the need for dedicated housings, thus increasing the valve's structural simplicity and compactness. The valve that is the subject of the present invention is therefore simple and economical to produce. The presence of the compensating element 25 surrounding the tubular portion 23 prevents risks of deformation of portion 23 and the valve seat 7, preventing consequent risks of incorrect closure of the opening / closing member 8; likewise, risks of failure or restriction of the passage section for the fluid are avoided. It is evident that numerous variations can be made by a person skilled in the art to the valve described as an example, without thereby departing from the scope of the invention as defined in the following claims. Figure 16 illustrates a variant embodiment where a pin 9b is mounted centrally within the cavity 9a of the core 9, around which the spring 17 is located. In addition to guiding the spring 17 under compression, the pin 9b allows for a reduction in the usable volume of the cavity 9a that can be filled by the fluid that might otherwise reach the area between the core 9 and the opposing core 18. The volume of this fluid is thus reduced, limiting the negative effects that could be caused by an increase in its volume due to freezing. The pin 9b is preferably made of metal or another rigid material; however, it could advantageously be made of an elastic and / or compressible material, for example, a material similar to that of element 25, so that it can undergo deformation and / or compression in the presence of fluid freezing.
Claims
1. A valve for controlling the flow of a fluid, comprising: - a valve body having at least a first body part (2) made of a polymer or plastic material, preferably molded; - a fluid passage chamber (6), defined within the first body part (2) and comprising at least one fluid inlet (6a) and at least one fluid outlet (6b); - a valve seat (7) defined within the fluid passage chamber (6); - closing means (8-9) for closing the fluid, displaceable relative to the valve seat (7) to control the fluid flow; and - a compensating element (25) arranged to compensate for a possible increase in the volume and / or pressure of the fluid, the compensating element (25) comprising a compensating body (26) made of an elastically deformable and / or compressible material,the polymer or plastic material of the first body part (2) being more rigid than the elastically deformable and / or compressible material of the compensating body (26), the compensating body (26) having a substantially axially hollow cylindrical shape with a generally cylindrical peripheral wall (27), the valve (1) being characterized in that the first body part (2) comprises a tubular portion (23) extending between the valve seat (7) and one of the fluid inlets (6a) and the fluid outlet (6b), towards the fluid passage chamber (6), and in that the compensating body (26) is mounted within the fluid passage chamber (6) so as to at least partially surround the tubular portion (23).
2. The valve according to claim 1,wherein the tubular portion (23) has an average thickness less than the average thickness of a peripheral wall (2b) of the first part of the body (2) that peripherally delimits the chamber for the passage of the fluid (6).
3. The valve according to claim 1 or claim 2, wherein - the other part of the fluid inlet (6a) and the fluid outlet (6b) is arranged laterally with respect to the tubular portion (23); and - the compensating body (26) defines at least one lateral passage (28) to allow the passage of fluid between the valve seat (7) and the other part of the fluid inlet (6a) and the fluid outlet (6b).
4. The valve according to any of claims 1-3, wherein within the fluid passage chamber (6) is defined one of a polarizing element (30) and one opposing polarizing element (29), and the compensation body (26) comprises the other of a polarizing element (30) and one opposing polarizing element (29),5. The valve according to claims 3 and 4, wherein at least one side passage (28) and at least one opposing polarizing element (29) are defined in substantially opposite positions on the generally cylindrical wall (27) of the compensating body (26).
6. The valve according to claim 4 or claim 5, wherein at least one side passage (28) comprises a recess extending from a first longitudinal end (31) of the generally cylindrical wall (27) of the compensating body (26), and at least one opposing polarizing element (29) comprises a recess extending from a second longitudinal end (32) of the generally cylindrical wall (27), opposite said first longitudinal end (31).
7. The valve according to any one of claims 1-6,wherein at least one of the fluid passage chambers (6) and the compensating element (25) comprises coupling means (33, 34) arranged to maintain the compensating body (26) in a substantially predetermined axial position within the fluid passage chamber (6).
8. The valve according to claim 7, wherein the coupling means comprise at least one rib or relief (33) extending over at least a portion of a circumference of the compensating body (26), possibly in combination with a corresponding seat or recess (34) defined in a surface delimiting the fluid passage chamber (6), or vice versa.
9. The valve according to any of claims 1-8, wherein the closing means (8-9) are displaceable with respect to the valve seat (7) at least between a closed position, where fluid cannot pass from the fluid inlet (6a) to the fluid outlet (6b),and an open position, where fluid can pass from the fluid inlet (6a) to the fluid outlet (6b), in a direction that is generally parallel to a longitudinal extension direction of the tubular portion (23) and / or the compensating element (25).
10. The valve according to any of claims 1-9, further comprising an actuating system (10-13) configured to control the displacement of the closing means (8-9), the actuating system (10-13) preferably comprising an electric actuator, most preferably a solenoid actuator.
11. A fluidic circuit or device, comprising a valve according to any of claims 1-10.