Piezoelectric valve

Abstract

A piezoelectric valve includes a valve body having an inlet conduit for pressurized fluid and having a fluid outlet conduit and a valve seat in fluid communication with the inlet conduit and the outlet conduit. The valve is provided with a piezoelectric plate. An internal chamber is provided within the valve body, in which a sealing membrane having a closing portion facing the valve seat is accommodated. The piezoelectric plate has a plate distal portion operatively connected to the sealing membrane by at least one rigid force transfer element (e.g., a ball).

Description

Technical Field

[0001] The present invention relates to a piezoelectric valve, wherein the flow rate of fluid circulating within the valve is controlled by the movement of a flow control element driven by a piezoelectric actuator. Background Technology

[0002] A known piezoelectric valve includes a valve body having: an inlet passage for pressurizing fluid; a fluid outlet passage; and a valve seat that provides fluid communication between the inlet and outlet passages. A piezoelectric plate is housed within the valve body and is adapted to deform upon electrical actuation to engage and disengage with the valve seat, thereby regulating the fluid flow through the valve seat.

[0003] Examples of this valve are described in documents DE102018219017, DE102016213228, DE19957953, and WO2009 / 010117. Summary of the Invention

[0004] The object of this invention is to provide a piezoelectric valve of the above type that can provide improved performance in terms of regulating fluid flow and power consumption.

[0005] Another aspect of the invention is to provide a piezoelectric valve of particularly small size.

[0006] Another object of the present invention is to provide a piezoelectric valve that is particularly suitable for applications where it is required that the fluid flowing through the valve is not contaminated, such as in the medical or food fields.

[0007] This objective is achieved by the piezoelectric valve according to claim 1. The dependent claims describe preferred or advantageous embodiments of the piezoelectric valve. Attached Figure Description

[0008] The features and advantages of the piezoelectric valve according to the invention will become apparent from the following description of its preferred embodiments with reference to the accompanying drawings, which are provided only by way of non-limiting examples, wherein:

[0009] Figure 1 This is a perspective view of a piezoelectric valve;

[0010] Figure 2 This is a perspective view of the valve from above;

[0011] Figure 3 It is the axial cross-section of the valve;

[0012] Figure 4 and Figure 4a These are two enlarged views of the lower part of the valve, showing the valve in its open and closed configurations, respectively.

[0013] Figure 5It is the axial cross-section of the valve, which has a valve seat and a nozzle at the bottom;

[0014] Figure 6 This is a perspective view of the separate components of a piezoelectric valve;

[0015] Figure 7 This is a perspective view of the separate components at the bottom of the valve body; and

[0016] Figure 8 This is a perspective view of the separate components of the piezoelectric plate and the separate components of the push spring element associated with the piezoelectric plate. Detailed Implementation

[0017] In the accompanying drawings, reference numeral 1 indicates the entire piezoelectric valve according to the invention.

[0018] The piezoelectric valve 1 includes a valve body 10 forming an inlet conduit 12 for pressurized fluid and an outlet conduit 14 for pressurized fluid. A valve seat 16 is disposed in or inserted into the valve body 10, and the valve seat 16 provides fluid communication between the inlet conduit 12 and the outlet conduit 14.

[0019] In one embodiment, the valve body 10 has a prismatic shape and extends primarily along the body axis X, which in the illustrated embodiment is a vertical axis.

[0020] Therefore, in the remainder of this specification, terms such as “upper,” “lower,” or their synonyms will be used with reference to the embodiments shown in the accompanying drawings, wherein the piezoelectric valve 1 is arranged to have a predominantly vertical extension.

[0021] In one embodiment, the valve body 10 may be assembled on a base 2 in which at least two pipes 2a, 2b are provided, for example for supply and discharge, and these pipes are adapted to be in fluid communication with an inlet pipe 12 and an outlet pipe 14.

[0022] The valve body 10 houses a piezoelectric plate 20, which is adapted to deform when electrically actuated. As will be described in more detail below, the piezoelectric plate 20 is actuated by a voltage difference to open and close the valve seat 16, thereby regulating the fluid flow rate within the valve.

[0023] In one embodiment, the piezoelectric plate 20 extends primarily along the plate axis Y, which is parallel to or coincides with the main body axis X.

[0024] The piezoelectric plate 20 terminates at the distal portion 204. After the piezoelectric plate 20 is electrically actuated, the distal portion 204 moves in a direction substantially orthogonal to the plate axis Y.

[0025] Furthermore, an internal chamber 22 is provided within the valve body 10. This internal chamber 22 communicates with the valve seat 16 and the outlet pipe 14. Therefore, when the valve seat 16 is (at least partially) open, the internal chamber 22 is adapted to be filled with fluid.

[0026] A sealing membrane 24 is housed inside the internal chamber 22. The sealing membrane 24 serves both as a separation device between the fluid circulating inside the valve and the piezoelectric plate 20, and as a closing element of the valve seat 16.

[0027] More specifically, the sealing diaphragm 24 has a shutter portion 242 facing the valve seat 16. Furthermore, the sealing diaphragm 24 is arranged at least partially around the piezoelectric plate 20 to prevent contact between the piezoelectric plate 20 and the fluid circulating in the valve.

[0028] The distal portion 204 of the piezoelectric plate 20 is operatively connected to the sealing membrane 24 via at least one rigid force transmission element 26.

[0029] Therefore, the distal portion 204 of the plate can move between a first position and a second position, in which the distal portion deforms at least the closing portion 242 of the sealing membrane 24 by at least one rigid element 26 to close the valve seat 16. Figure 4a In this second position, the distal portion allows at least the closed portion 242 to remain in an undeformed state separated from the valve seat 16. Figure 4 In this second position, valve seat 16 is therefore open.

[0030] It should be noted that the piezoelectric valve 1 can be used both as a switching valve to allow or prevent fluid flow through the valve seat 16 and as a proportional valve to regulate fluid flow. In the second case, in practice, by modulating the intensity of the voltage difference applied to the piezoelectric plate 20, the offset of the distal portion 204 of the plate may be adjusted accordingly, and thus the deformation of the closing portion 242 of the sealing diaphragm 24 is adjusted. In other words, the closing portion 242 can exhibit a maximum deformation configuration, an undeformed configuration, and an intermediate deformation configuration. In the maximum deformation configuration, the closing portion seals the valve seat 16; in the undeformed configuration, the closing portion fully opens the valve seat 16; and in the intermediate deformation configuration, the closing portion regulates the fluid flow through the valve seat 16.

[0031] In one embodiment, the piezoelectric valve 1 further includes a push spring element 30 that cooperates with the piezoelectric plate 20.

[0032] In detail, when the piezoelectric plate 20 is not electrically actuated, the distal portion 204 of the plate is pushed by the spring element 30 to be held in a first position in which the valve seat 16 is completely sealed closed by the closing portion 242 of the sealing membrane 24.

[0033] When the piezoelectric plate 20 is electrically actuated, the distal portion 204 of the plate overcomes the force pushing the spring element 30 and switches from the first position to the second position (or, in the case of a proportional valve, to the intermediate position).

[0034] In one implementation variation, the function of the piezoelectric valve can be reversed. In fact, when the piezoelectric plate 20 is not electrically actuated, the distal portion 204 of the plate can be biased by the spring element 30 to remain in a second position, in which the valve seat 16 is fully open; conversely, when the piezoelectric plate 20 is electrically actuated, the distal portion 204 of the plate overcomes the force of the spring element 30 to switch from the second position to the first position (or, in the case of a proportional valve, to the intermediate position).

[0035] In one embodiment, the distal portion 204 of the plate is positioned between two rigid force transmission elements 26, which are identical to each other and engage corresponding opposing portions of the sealing membrane 24, namely the closing portion 242 and the opposing portion 244. Thus, when the distal portion 204 is in the second position, the resultant force exerted on the distal portion 204 by the pressurized fluid present in the internal chamber 22 is essentially zero. Therefore, in this case, the piezoelectric plate 20 must be electrically driven to overcome only the force pushing the spring element 30, and not the pressure exerted by the fluid.

[0036] In one embodiment, at least one rigid force transmission element 26 is a sphere positioned to translate between the distal portion 204 of the plate and the closed portion 242 of the sealing membrane 24.

[0037] In one embodiment, the rigid force transmission element 26 is housed within a guide seat 262 disposed or inserted into the valve body 10.

[0038] In the illustrated embodiment, the distal portion 202 of the plate is inserted between two spheres 26, each sphere engaging a corresponding portion 242, 244 of the sealing membrane. The spheres 26 and portions 242, 244 of the sealing membrane 24 are arranged substantially in a mirror manner with respect to the plate axis Y.

[0039] In one embodiment, the inlet pipe 12, the outlet pipe 14, and the valve seat 16 are disposed in or included in the exterior 102 of the valve body 10, for example, also forming the exterior of the base of the valve body 10.

[0040] The distal portion 204 of the plate is housed within the interior 104 of the valve body 10, which together with the exterior 102 forms an internal chamber 22. The distal portion 204 of the plate and the actuating spring element 30 (if present) extend axially within the plate chamber 106 disposed within the interior 104.

[0041] Within the interior 104 of the valve body 10, a guide seat 262 is configured to accommodate or house at least one rigid force transmission element 26. A sealing diaphragm 24 is sealingly fitted onto the interior 104 of the valve body 10, and the sealing diaphragm closely matches the internal shape of the valve body.

[0042] For example, the outer part 102 has a cup shape, in which an inner cavity 108 is formed.

[0043] This internal cavity 108 is defined by sidewalls 110.

[0044] In one embodiment, the interior 104 forms at least one flat wall 112 (in the illustrated embodiment, the two flat walls are opposite and parallel). This at least one flat wall 112 faces the valve seat 16. Within this at least one flat wall 112, preferably within a pair of opposite flat walls 112, an opening 114 is provided, which forms or is provided with a guide seat 262 communicating with the internal chamber 22 and the plate chamber 106. A rigid force transmission element 26 can protrude from the opening 114 facing the valve seat 16 to deform the closing portion 242 of the sealing membrane 24.

[0045] In one embodiment, the sealing membrane 24 has a cup shape. Furthermore, the sealing membrane 24 can be locked in place by one of its thickened upper edges 146, which is held between the sidewall of the inner 104 and the facing sidewall of the outer 102 that defines the inner cavity 108.

[0046] In one embodiment, a valve seat 26 is disposed at the end of a nozzle 120, which is sealed into a nozzle seat 122 disposed in the valve body 10, for example, within the outer 102 of the valve body 10. This nozzle seat 122 is in fluid communication with the inlet pipe 12 and the internal chamber 22.

[0047] In one embodiment, the nozzle 120 and the valve seat 26 extend about the nozzle axis Z, which is perpendicular to the plate axis Y.

[0048] In one embodiment, the nozzle seat 122 is also opened outward, making it possible to adjust the insertion depth of the nozzle 120 into the nozzle seat 122 to adjust the distance between the valve seat 16 and the closed portion 242 of the sealing diaphragm 24 when the closed portion 242 is in the deformed position, and thus regulate the fluid flowing out of the valve seat.

[0049] In one embodiment, the steering spring element 30 is made using a leaf spring extending along the piezoelectric plate 20, and the distal end 302 of the steering spring element is provided with, for example, a spherical protrusion to engage with the distal portion 204 of the plate.

[0050] In one embodiment, the actuating spring element 30 is made of a conductive material and is electrically connected to the piezoelectric plate 20, for example, via an electrical connection protrusion 304.

[0051] In one embodiment, the piezoelectric plate 20 actually has a first pole and a second pole. The first pole is electrically connected to a first power terminal 203, which is made, for example, by an electrical contact having at least one blade 203' arranged to contact this first pole. The second pole is electrically connected, for example, to a push spring element 30 via an electrical connection protrusion 304, which also serves as a second power terminal.

[0052] For example, the first power terminal 203 and the push spring element 30 have corresponding attachments 203'', 306 protruding from above the valve body 10, for example.

[0053] In one embodiment, the proximal portion 202 of the piezoelectric plate 20 and the actuating spring element 30 are attached to the valve body 10 and held stably by the geometric matching of complementary parts of the upper portion 105 of the valve body 10. This allows for quick and easy assembly of the valve body, the piezoelectric plate using the associated electrical contacts, and the actuating spring element.

[0054] It is clear from the above that the proposed piezoelectric valve can achieve the intended purpose.

[0055] In particular, fluid flow regulation is achieved in a highly precise and reliable manner by converting the deformation of the piezoelectric plate into the translation of a rigid force transmission element acting on the sealing diaphragm.

[0056] Furthermore, using a ball as a rigid force transmission element makes it possible to deform the closed portion of the sealing membrane, which is particularly suitable for ensuring the airtight closure of the valve seat.

[0057] Furthermore, the use of a sealing membrane prevents any contact between the valve's fluid components and the piezoelectric actuation components, thus making the valve suitable for applications where the fluid circulating within the valve is free of impurities.

[0058] The internal chamber 22 surrounding the sealing membrane 24 minimizes the force acting on the plate when the valve seat is open and pressurized fluid is present in the internal chamber 22. The sealing membrane acts on the piezoelectric plate 20 through a rigid force transmission element 26 arranged in a mirror manner relative to the plate.

[0059] Those skilled in the art can make various modifications, adjustments, adaptations, and substitutions for the components with other components functionally equivalent to embodiments of the piezoelectric valve according to the invention to meet occasional needs without departing from the scope of the appended claims. Each feature described as belonging to a possible embodiment can be obtained independently of the other described embodiments.

Claims

1. A piezoelectric valve, comprising: - A valve body having an inlet pipe for pressurizing fluid and a fluid outlet pipe, and a valve seat for fluid communication between the inlet pipe and the outlet pipe; - A piezoelectric plate adapted to deform when electrically actuated, the piezoelectric plate being housed within the valve body; in: - An internal chamber communicating with the valve seat and the outlet pipe is formed in the valve body; - A sealing membrane is housed in the internal chamber, the sealing membrane having a closed portion facing the valve seat, and the sealing membrane is also arranged at least partially around the piezoelectric plate to avoid contact between the piezoelectric plate and the fluid circulating in the valve; - The piezoelectric plate has a distal portion operatively connected to the sealing membrane by at least one rigid force transmission element, the distal portion being movable between a first position and a second position, in the first position, the distal portion deforms at least the closing portion of the sealing membrane to close the valve seat by at least one of the rigid elements, and in the second position, the distal portion allows at least the closing portion to remain in an undeformed state in which the closing portion is disengaged from the valve seat.

2. The piezoelectric valve according to claim 1, wherein, When the piezoelectric plate is not electrically actuated, the distal portion of the plate is biased by a push spring element to remain in the first position, and wherein, when the piezoelectric plate is electrically actuated, the distal portion of the plate overcomes the force of the push spring element to switch from the first position to the second position.

3. The piezoelectric valve according to claim 1 or 2, wherein, The distal portion of the plate is positioned between two rigid force transmission elements, which are identical to each other and engage with corresponding opposite portions of the sealing membrane, such that when the distal portion of the plate is in the second position, the resultant force of the forces exerted on the distal portion of the plate by the pressurized fluid in the internal chamber is substantially zero.

4. The piezoelectric valve according to any one of the preceding claims, wherein, At least one of the rigid force transmission elements is a sphere, which is positioned to translate between the distal portion of the plate and the closed portion of the sealing membrane.

5. The piezoelectric valve according to any one of the preceding claims, wherein, The inlet pipe, the outlet pipe, and the valve seat are disposed or included in the exterior of the valve body, wherein the distal portion of the plate is accommodated in the interior of the valve body, the interior and the exterior together forming the internal chamber, and at least one element seat is disposed or accommodated in the interior, at least one of the rigid force transmission elements is received in the element seat in a translational manner, and wherein the sealing membrane is sealed to the interior of the valve body and the sealing membrane closely matches the internal shape of the valve body.

6. The piezoelectric valve according to any one of the preceding claims, wherein, The valve seat is disposed at the end of the nozzle, the nozzle is sealed and inserted into the nozzle seat disposed in the valve body, and the nozzle seat is in fluid communication with the inlet pipe and the internal chamber.

7. The piezoelectric valve according to any one of claims 2 to 6, wherein, The push spring element is a leaf spring extending along the piezoelectric plate, and the distal end of the push spring engages with the distal portion of the plate.

8. The piezoelectric valve according to any one of the preceding claims, wherein, The push spring element is made of a conductive material and is electrically connected to the electrodes of the piezoelectric plate.

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