A proportional flow control valve based on a double-layer annular piezoelectric ceramic stack and its application method

Abstract

This invention relates to the field of proportional valve equipment, and proposes a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack and its usage method. The valve includes a valve cover, a piezoelectric ceramic drive mechanism, a valve core, and a valve body. The valve cover has an electrode core and an air inlet pipe in its center, which communicates with the valve body. The piezoelectric ceramic drive mechanism is located within the valve body and is connected to the electrode core via a lead wire. The valve body has an opening at its upper part, which is tightly connected to the valve cover. An opening structure is also provided at the bottom of the valve body, and a nozzle is positioned at the opening. One end of the valve core passes through the piezoelectric ceramic drive mechanism and is pressed against the opening of the nozzle by a first elastic limiting member, achieving a seal with a valve seat. The other end of the valve core is connected to the piezoelectric ceramic drive mechanism via a nut fixedly mounted on the top of the piezoelectric ceramic drive mechanism.

Description

Technical Field

[0001] This invention relates to the field of proportional valve equipment, and more specifically, to a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack and its usage method. Background Technology

[0002] Proportional flow control valves are widely used in high-precision fluid control fields, such as pressure and flow control, due to their continuously adjustable flow rate and high control accuracy. According to different driving methods, proportional flow control valves can be divided into electromagnetic proportional valves, piezoelectric proportional valves, and magnetostrictive proportional valves. Among them, piezoelectric proportional valves have become a current research hotspot due to their high displacement resolution, fast response speed, and low power consumption. They are also increasingly being applied in the aerospace field, such as flow control units for working fluid supply units in electric propulsion systems, pressure control units in cold gas propulsion systems, and flow control units with nozzles.

[0003] To apply piezoelectric proportional valves to propulsion systems in the aerospace field, it is necessary to address the issues of effective valve opening and valve core displacement resolution. The effective valve opening is limited by the maximum stroke of the piezoelectric ceramic drive module and the deformation at the valve port caused by sealing forces. Small deformation at the valve seat results in poor sealing, while large deformation reduces the effective valve opening or even prevents the valve from opening. The valve core displacement resolution depends on the displacement resolution of the piezoelectric ceramic drive module. The displacement resolution of the piezoelectric ceramic material itself is mainly limited by the applied voltage resolution. However, traditional piezoelectric proportional valves use displacement amplification structures and coupling stacking methods, which, while increasing the stroke, amplify the displacement resolution of the piezoelectric ceramic drive module by the same factor, ultimately reducing the final flow control resolution of the proportional valve. Current piezoelectric proportional valves mainly achieve displacement amplification by stacking multiple single-piece piezoelectric ceramics or by introducing two-stage flexible hinges. However, these methods reduce the displacement resolution of the piezoelectric drive module and do not consider the effective opening issue caused by the sealing at the valve port. Summary of the Invention

[0004] To overcome the shortcomings of existing piezoelectric proportional valves, such as low valve core displacement resolution and failure to consider the effective opening caused by valve port sealing, this invention provides a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack and its usage method.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A proportional flow control valve based on a double-layer annular piezoelectric ceramic stack includes a valve cover, a piezoelectric ceramic drive mechanism, a valve core, and a valve body, wherein:

[0007] An electrode core is provided on the valve cover, and an air inlet pipe is provided in the middle of the valve cover, which is connected to the valve body;

[0008] The piezoelectric ceramic drive mechanism is disposed in the valve body, and the piezoelectric ceramic drive mechanism is connected to the electrode core through a lead wire;

[0009] The valve body has an opening at the top and is tightly connected to the valve cover. The valve body has an opening structure at the bottom, and a nozzle is provided at the opening structure position.

[0010] One end of the valve core passes through the piezoelectric ceramic drive mechanism and is pressed against the opening position of the nozzle by the first elastic limiting member and cooperates with the valve seat to achieve a seal; the other end of the valve core is connected to the piezoelectric ceramic drive mechanism by a nut fixedly set on the top of the piezoelectric ceramic drive mechanism.

[0011] As a preferred embodiment, the piezoelectric ceramic drive mechanism includes an upper cover, a first piezoelectric ceramic stack, a U-shaped connector, a second piezoelectric ceramic stack, and an annular substrate, wherein: the upper cover is disposed above the first piezoelectric ceramic stack, the first piezoelectric ceramic stack is placed inside the U-shaped connector, and the second piezoelectric ceramic stack is sleeved on the outer periphery of the U-shaped connector; the annular substrate supports the second piezoelectric ceramic stack and the U-shaped connector in the middle of the valve body; the bottom of the U-shaped connector has a through hole for the valve core to pass through; a limiting member is fixed in the upper part of the valve body, and the lower part of the limiting member is pressed against the upper cover by a second elastic limiting member.

[0012] As a preferred embodiment, the valve cover includes two sets of electrode cores, which are connected to the first piezoelectric ceramic stack and the second piezoelectric ceramic stack respectively via leads.

[0013] As a preferred embodiment, the connection positions of the first piezoelectric ceramic stack with the U-shaped connector and the top cover are respectively coated with epoxy resin adhesive; the connection positions of the second piezoelectric ceramic stack with the U-shaped connector and the annular substrate are respectively coated with epoxy resin adhesive.

[0014] As a preferred embodiment, the heights of the first piezoelectric ceramic stack and the second piezoelectric ceramic stack are equal.

[0015] As a preferred embodiment, the second elastic limiting member includes a disc spring; the limiting member includes a disc spring retaining ring, which is threadedly connected and fixed to the inner wall of the valve body.

[0016] As a preferred embodiment, the first elastic limiting member includes a leaf spring with at least three cantilever beams; the portion of the valve core extending out of the piezoelectric ceramic drive mechanism is provided with a flange; the outer edge of the leaf spring is fixed to the inner wall of the valve body by a snap ring, and the inner edge of the leaf spring is sleeved on the valve core and connected to the flange.

[0017] As a preferred embodiment, the cantilever beam on the leaf spring comprises a helical or vortex-shaped cantilever beam.

[0018] As a preferred embodiment, the upper surface of the valve core flange is horizontally aligned with the lower surface of the retaining ring.

[0019] Furthermore, the present invention also proposes a method for using a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack, comprising the following steps:

[0020] After snapping the valve seat into the nozzle, place it into the valve body, and then weld the nozzle to the valve body.

[0021] The valve core is placed into the valve body, and the end of the valve core is inserted into the valve seat and mates with the opening of the nozzle;

[0022] The first elastic limiting member is sleeved outside the valve core and pre-tightened.

[0023] The piezoelectric ceramic drive mechanism is placed inside the valve body and sleeved on the outside of the valve core. The nut is passed through the top of the valve core and connected to the top of the piezoelectric ceramic drive mechanism. The nut is then welded to the top of the valve core.

[0024] The piezoelectric ceramic drive mechanism and the electrode core are connected by lead wires, and the valve cover and valve body are sealed by locking threads;

[0025] Connect the air inlet pipe provided in the valve cover to the air source;

[0026] The electrode core is connected to an external driving power supply via a lead wire. Voltage is applied to the piezoelectric ceramic driving mechanism through the electrode core, and the piezoelectric ceramic driving module is energized and displaced, thereby driving the valve core to move.

[0027] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0028] This invention indirectly controls the effective opening of the flow control valve by applying a pre-tight sealing force to the valve seat at the valve body opening position using the stiffness and compression of the first elastic limiting member; and by connecting the electrode core provided on the valve cover to the piezoelectric ceramic drive mechanism in the valve body, the piezoelectric proportional valve flow control is achieved by applying voltage to the piezoelectric ceramic drive mechanism through the electrode core.

[0029] The present invention also uses a piezoelectric ceramic driving mechanism composed of a first piezoelectric ceramic stack and a second piezoelectric ceramic stack. The first piezoelectric ceramic stack and the second piezoelectric ceramic stack are independently controlled by two sets of electrode cores, thereby increasing the flow control range of the piezoelectric proportional valve without reducing its flow control resolution. Attached Figure Description

[0030] Figure 1 This is an exploded view of the proportional flow control valve based on a double-layer annular piezoelectric ceramic stack, as described in Example 1.

[0031] Figure 2 This is a cross-sectional view of the proportional flow control valve based on a double-layer annular piezoelectric ceramic stack according to Example 1.

[0032] Figure 3 This is a schematic diagram of the leaf spring in Example 3.

[0033] Figure 4 This is a cross-sectional view of the leaf spring in Example 3.

[0034] Figure 5 This is a flowchart illustrating the usage method of the proportional flow control valve in Example 4.

[0035] Among them, 1-valve cover, 101-air inlet pipe, 102-O-ring groove, 2-piezoelectric ceramic drive mechanism, 201-top cover, 202-first piezoelectric ceramic stack, 203-U-shaped connector, 204-second piezoelectric ceramic stack, 205-annular substrate, 3-valve core, 301-flange, 4-valve body, 5-electrode core, 6-nozzle, 7-first elastic limiting member, 8-valve seat, 9-nut, 10-limiting member, 11-second elastic limiting member, 12-circlip, 13-waist. Detailed Implementation

[0036] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0037] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions;

[0038] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Example 1

[0041] This embodiment proposes a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack, such as Figure 1 , 2 The diagram shown is a schematic of the proportional flow control valve based on a double-layer annular piezoelectric ceramic stack in this embodiment.

[0042] The proportional flow control valve based on a double-layer annular piezoelectric ceramic stack proposed in this embodiment includes a valve cover 1, a piezoelectric ceramic drive mechanism 2, a valve core 3, and a valve body 4, wherein:

[0043] An electrode core 5 is provided on the valve cover 1, and an air inlet pipe 101 is provided in the middle of the valve cover 1. The air inlet pipe 101 is connected to the valve body 4.

[0044] The piezoelectric ceramic drive mechanism 2 is disposed inside the valve body 4, and the piezoelectric ceramic drive mechanism 2 is connected to the electrode core 5 through a lead wire.

[0045] The valve body 4 has an opening at the top and is tightly connected to the valve cover 1. The valve body 4 has an opening at the bottom and a nozzle 6 is provided at the opening.

[0046] One end of the valve core 3 passes through the piezoelectric ceramic drive mechanism 2 and is pressed against the opening position of the nozzle 6 by the first elastic limiting member 7 and cooperates with the valve seat 8 to achieve a seal; the other end of the valve core 3 is connected to the piezoelectric ceramic drive mechanism 2 by a nut 9 fixedly set on the top of the piezoelectric ceramic drive mechanism 2.

[0047] In the specific implementation process, the electrode core 5 is connected to an external piezoelectric ceramic driving power supply by a lead wire. Voltage is applied to the piezoelectric ceramic driving mechanism 2 through the electrode core 5. The valve core 3 moves under the driving action of the piezoelectric ceramic driving mechanism 2 to realize the flow control of the piezoelectric proportional valve.

[0048] The valve core 3 is pressed against the valve seat 8 located above the nozzle 6 outlet by the force of the first elastic limiting member 7 to achieve a seal, thus realizing the normally closed state of the valve when no power is applied. The nut 9 connected to the top of the valve core 3 is welded and fixed to the top of the piezoelectric ceramic drive mechanism 2. When the piezoelectric ceramic drive module is energized and displaced, it will drive the valve core 3 to move.

[0049] In the specific implementation process, by designing the stiffness and compression of the first elastic limiting member 7, the purpose of indirectly designing the sealing force between the valve core 3 and the valve seat 8 can be achieved.

[0050] In this embodiment, the effective opening degree of the flow control valve is indirectly controlled by applying a pre-tight sealing force to the valve seat 8 at the opening position of the valve body 4 using the stiffness and compression of the first elastic limiting member 7; the piezoelectric ceramic drive mechanism 2 inside the valve body 4 is connected to the electrode core 5 provided on the valve cover 1, and the piezoelectric ceramic drive mechanism 2 is applied to the piezoelectric proportional valve flow control by applying voltage through the electrode core 5.

[0051] Alternatively, the valve cover 1 may be a flange cover, and the air inlet pipe 101 provided thereon may be connected to the air source by means of adhesive PU tubing or welding other standard joints.

[0052] Alternatively, an O-ring groove 102 is provided at the connection position between the valve cover 1 and the valve body 4, in which an O-ring is built-in to ensure the sealing state inside the valve body 4.

[0053] Alternatively, locking threads are provided at matching positions on the valve cover 1 and the valve body 4, and the valve cover 1 and the valve body 4 are locked and sealed using bolts or other parts to ensure the sealing state inside the valve body 4.

[0054] Alternatively, the nozzle 6 may be an air circuit adapter, and the nozzle 6 has a groove on the outside of the valve body 4 to facilitate welding and sealing.

[0055] Example 2

[0056] This embodiment is an improvement upon the proportional flow control valve based on a double-layer annular piezoelectric ceramic stack proposed in Embodiment 1.

[0057] The proportional flow control valve based on a double-layer annular piezoelectric ceramic stack proposed in this embodiment includes a valve cover 1, a piezoelectric ceramic drive mechanism 2, a valve core 3, and a valve body 4. Specifically: an electrode core 5 is disposed on the valve cover 1, and an air inlet pipe 101 is disposed in the middle of the valve cover 1, communicating with the valve body 4; the piezoelectric ceramic drive mechanism 2 is disposed inside the valve body 4, and is connected to the electrode core 5 via a lead wire; the valve body 4 has an opening at the top and is tightly connected to the valve cover 1, and an opening structure is provided at the bottom of the valve body 4, with a nozzle 6 disposed at the opening structure position; one end of the valve core 3 passes through the piezoelectric ceramic drive mechanism 2 and is pressed against the opening position of the nozzle 6 by a first elastic limiting member 7, and cooperates with a valve seat 8 to achieve a seal; the other end of the valve core 3 is connected to the piezoelectric ceramic drive mechanism 2 by a nut 9 fixedly disposed on the top of the piezoelectric ceramic drive mechanism 2.

[0058] Furthermore, the piezoelectric ceramic driving mechanism 2 in this embodiment includes an upper cover 201, a first piezoelectric ceramic stack 202, a U-shaped connector 203, a second piezoelectric ceramic stack 204, and an annular substrate 205.

[0059] The upper cover 201 is positioned above the first piezoelectric ceramic stack 202, which is placed inside the U-shaped connector 203. The second piezoelectric ceramic stack 204 is fitted around the outer periphery of the U-shaped connector 203. The annular substrate 205 supports the second piezoelectric ceramic stack 204 and the U-shaped connector 203 in the middle of the valve body 4. The bottom of the U-shaped connector 203 has a through hole for the valve core 3 to pass through. A limiting member 10 is fixed in the upper part of the valve body 4, and the lower part of the limiting member 10 is pressed against the upper cover 201 by a second elastic limiting member 11.

[0060] In this embodiment, the top cover 201 may optionally be a ceramic top cover 201, which may optionally have a plurality of through holes for connection and fixation with the first piezoelectric ceramic stack.

[0061] Furthermore, in an optional embodiment, the first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204 are annular piezoelectric ceramic stacks.

[0062] like Figure 2 As illustrated, in this embodiment, the first piezoelectric ceramic stack 202 is placed inside the U-shaped connector 203, and the bottom of the first piezoelectric ceramic stack 202 is engaged with a groove provided at the bottom of the U-shaped connector 203. The second piezoelectric ceramic stack 204 is sleeved on the outer periphery of the U-shaped connector 203, and the upper surface of the second piezoelectric ceramic stack 204 is fixedly connected to a flange provided outward at the top of the U-shaped connector 203. The annular substrate 205 may optionally be engaged with a stepped groove provided on the inner wall of the valve body 4, and the annular substrate 205 supports the second piezoelectric ceramic stack 204 and the U-shaped connector 203 in the middle of the valve body 4.

[0063] Alternatively, the top cover 201, the U-shaped connector 203, and the substrate may be made of metal materials, such as stainless steel or aluminum alloy.

[0064] Furthermore, in an optional embodiment, the valve cover 1 includes two sets of electrode cores 5, which are connected to the first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204 respectively via leads. Optionally, the upper cover 201 has a through hole of an appropriate size for the leads to pass through.

[0065] In this embodiment, the piezoelectric ceramic drive mechanism 2 is composed of the first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204. The first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204 are independently controlled by two sets of electrode cores 5, which realizes that the flow control range of the piezoelectric proportional valve is increased without reducing its flow control resolution.

[0066] Furthermore, in an optional embodiment, the connection positions of the first piezoelectric ceramic stack 202 with the U-shaped connector 203 and the top cover 201 are respectively coated with epoxy resin adhesive; the connection positions of the second piezoelectric ceramic stack 204 with the U-shaped connector 203 and the annular substrate 205 are respectively coated with epoxy resin adhesive.

[0067] Furthermore, in an optional embodiment, the heights of the first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204 are equal.

[0068] In this embodiment, the first piezoelectric ceramic stack 202 and the second piezoelectric ceramic stack 204 have the same height, thus their displacement stroke and resolution are also comparable. The second piezoelectric ceramic stack 204 has a larger volume, capacitance, and stiffness, making it suitable for applying a bias voltage to provide a constant bias displacement. The first piezoelectric ceramic stack 202 has a smaller volume, lower capacitance and stiffness, resulting in lower output but a faster response speed, making it more suitable for rapid and precise flow rate control. In practical implementation, the two sets of electrode cores 5 can be independently controlled to adapt to the control requirements.

[0069] Furthermore, in an optional embodiment, the second elastic limiting member 11 includes a disc spring; the limiting member 10 includes a disc spring retaining ring, which is threadedly connected and fixed to the inner wall of the valve body 4.

[0070] In this embodiment, the piezoelectric ceramic drive mechanism 2 is pressed into the valve body 4 by the second elastic limiting member 11; the disc spring retaining ring is connected to the valve body 4 by a thread. During assembly, a torque wrench is used to pre-tighten the piezoelectric ceramic drive module. During use, the disc spring retaining ring controls the compression force of the disc spring.

[0071] Example 3

[0072] This embodiment is an improvement on the proportional flow control valve based on a double-layer annular piezoelectric ceramic stack proposed in Embodiment 1 or 2.

[0073] The proportional flow control valve based on a double-layer annular piezoelectric ceramic stack proposed in this embodiment includes a valve cover 1, a piezoelectric ceramic drive mechanism 2, a valve core 3, and a valve body 4. Specifically: an electrode core 5 is disposed on the valve cover 1, and an air inlet pipe 101 is disposed in the middle of the valve cover 1, communicating with the valve body 4; the piezoelectric ceramic drive mechanism 2 is disposed inside the valve body 4, and is connected to the electrode core 5 via a lead wire; the valve body 4 has an opening at the top and is tightly connected to the valve cover 1, and an opening structure is provided at the bottom of the valve body 4, with a nozzle 6 disposed at the opening structure position; one end of the valve core 3 passes through the piezoelectric ceramic drive mechanism 2 and is pressed against the opening position of the nozzle 6 by a first elastic limiting member 7, and cooperates with a valve seat 8 to achieve a seal; the other end of the valve core 3 is connected to the piezoelectric ceramic drive mechanism 2 by a nut 9 fixedly disposed on the top of the piezoelectric ceramic drive mechanism 2.

[0074] Furthermore, in this embodiment, the first elastic limiting member 7 includes a leaf spring with at least three cantilever beams. The cantilever beams on the leaf spring are obtained by wire-cutting grooves on a disc, which is equivalent to several cantilever beams. In this embodiment, the axial and radial stiffness of the entire leaf spring can be changed by altering the length, thickness, and / or width of the cantilever beams.

[0075] Alternatively, the first elastic limiting member 7 may be made of beryllium copper.

[0076] Optionally, the geometry of the cantilever beam on the leaf spring includes a helix or a spiral. As an example, this embodiment uses an Archimedean spiral, i.e., an equidistant spiral. The geometry can be completely defined by changing the pitch, starting position, and rotation angle of the spiral, thus determining the final length of the cantilever beam. The thickness of the cantilever beam is equal to the initial thickness of the beryllium copper disk, and can also be adjusted by cutting disks of different thicknesses; the width of the cantilever beam is directly determined by the grooves cut during machining.

[0077] As an example, the leaf spring in this embodiment includes three cantilever beams. Figure 3 , 4 The diagram shown is a schematic diagram and cross-sectional view of the first elastic limiting member 7 in this embodiment. The cantilever beam is approximately 25mm long, and its thickness and width are approximately 0.9mm, achieving a final axial stiffness of approximately 10N / mm and a radial stiffness of approximately 30N / mm. The inner edge thickness of the leaf spring is controlled through machining; in this embodiment, the final compression of the leaf spring is approximately 1.2mm, and the expected pre-tightening sealing force is 12N, with an error of ±1.2N.

[0078] Furthermore, in this embodiment, the portion of the valve core 3 extending out of the piezoelectric ceramic drive mechanism 2 is provided with a flange 301. The outer edge of the leaf spring is fixed to the inner wall of the valve body 4 by a retaining ring 12, and the inner edge of the leaf spring is sleeved on the valve core 3 and connected to the flange 301.

[0079] The compression of the leaf spring is determined by the relative height difference between the upper surface of the flange 301 of the valve core 3 and the lower surface of the retaining ring 12, as well as the thickness of the inner edge of the leaf spring itself. In practice, the relative height difference can be controlled by designing the groove position on the inner wall of the valve body 4 for placing the retaining ring 12 and the height of the flange 301 of the valve core 3 relative to the valve seat 8.

[0080] Alternatively, the upper surface of the flange 301 of the valve core 3 is horizontally aligned with the lower surface of the retaining ring 12.

[0081] In this embodiment, the upper surface of the flange 301 of the valve core 3 basically coincides with the lower surface of the retaining ring 12, that is, the relative height difference is almost zero.

[0082] Alternatively, a gasket 13 is provided between the retaining ring 12 and the valve seat 8 for interference fit to achieve a sealing assembly.

[0083] Example 4

[0084] This embodiment proposes a method for using a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack, as described in any of Embodiments 1-3. Figure 5 The diagram shown is a flowchart illustrating the usage method of the proportional flow control valve in this embodiment.

[0085] The method of using the proportional flow control valve proposed in this embodiment includes the following steps:

[0086] S1. After snapping the valve seat 8 with the nozzle 6, place it into the valve body 4, and weld the nozzle 6 to the valve body 4;

[0087] S2. Place the valve core 3 into the valve body 4, and insert the end of the valve core 3 into the valve seat 8 and engage with the opening of the nozzle 6;

[0088] S3. The first elastic limiting member 7 is sleeved on the outside of the valve core 3 and pre-tightened.

[0089] S4. Place the piezoelectric ceramic drive mechanism 2 into the valve body 4 and sleeve it on the outside of the valve core 3. Pass the nut 9 through the top of the valve core 3 and connect it to the top of the piezoelectric ceramic drive mechanism 2. Weld the nut 9 to the top of the valve core 3.

[0090] S5. Connect the piezoelectric ceramic drive mechanism 2 and the electrode core 5 through lead wires, and seal the valve cover 1 and valve body 4 through locking threads.

[0091] S6. Connect the air inlet pipe 101 provided in the valve cover 1 to the air source;

[0092] S7. Connect the electrode core 5 to an external driving power supply through a lead wire, apply voltage to the piezoelectric ceramic driving mechanism 2, and the piezoelectric ceramic driving module is energized and displaced, thereby driving the valve core 3 to move.

[0093] The same or similar labels correspond to the same or similar parts;

[0094] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0095] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A proportional flow control valve based on a double-layer annular piezoelectric ceramic stack, characterized in that, It includes a valve cover (1), a piezoelectric ceramic drive mechanism (2), a valve core (3), and a valve body (4), wherein: An electrode core (5) is provided on the valve cover (1), and an air inlet pipe (101) is provided in the middle of the valve cover (1). The air inlet pipe (101) is connected to the valve body (4). The piezoelectric ceramic drive mechanism (2) is disposed inside the valve body (4), and the piezoelectric ceramic drive mechanism (2) is connected to the electrode core (5) through a lead wire; The valve body (4) has an opening at the top and is tightly connected to the valve cover (1). The valve body (4) has an opening structure at the bottom and a nozzle (6) is provided at the opening structure position. One end of the valve core (3) passes through the piezoelectric ceramic drive mechanism (2) and is pressed against the opening position of the nozzle (6) by the first elastic limiting member (7) and cooperates with the valve seat (8) to achieve a seal; the other end of the valve core (3) is connected to the piezoelectric ceramic drive mechanism (2) by a nut (9) fixedly set on the top of the piezoelectric ceramic drive mechanism (2). The piezoelectric ceramic driving mechanism (2) includes a top cover (201), a first piezoelectric ceramic stack (202), a U-shaped connector (203), a second piezoelectric ceramic stack (204), and an annular substrate (205), wherein: The upper cover (201) is placed on top of the first piezoelectric ceramic stack (202), the first piezoelectric ceramic stack (202) is placed inside the U-shaped connector (203), and the second piezoelectric ceramic stack (204) is sleeved on the outer periphery of the U-shaped connector (203); the annular substrate (205) supports the second piezoelectric ceramic stack (204) and the U-shaped connector (203) in the middle of the valve body (4); The bottom of the U-shaped connector (203) has a through hole for the valve core (3) to pass through; The upper part of the valve body (4) is fixed with a limiting member (10), and the lower part of the limiting member (10) is pressed against the upper cover (201) by a second elastic limiting member (11); The valve cover (1) includes two sets of electrode cores (5), which are connected to the first piezoelectric ceramic stack (202) and the second piezoelectric ceramic stack (204) respectively by leads.

2. The proportional flow control valve according to claim 1, characterized in that, The first piezoelectric ceramic stack (202) is coated with epoxy resin at the connection positions with the U-shaped connector (203) and the top cover (201); the second piezoelectric ceramic stack (204) is coated with epoxy resin at the connection positions with the U-shaped connector (203) and the annular substrate (205).

3. The proportional flow control valve according to claim 1, characterized in that, The first piezoelectric ceramic stack (202) has the same height as the second piezoelectric ceramic stack (204).

4. The proportional flow control valve according to claim 1, characterized in that, The second elastic limiting member (11) includes a disc spring; the limiting member (10) includes a disc spring retaining ring, which is threadedly connected and fixed to the inner wall of the valve body (4).

5. The proportional flow control valve according to any one of claims 1 to 4, characterized in that, The first elastic limiting member (7) includes a leaf spring with at least three cantilever beams; the valve core (3) extending out of the piezoelectric ceramic drive mechanism (2) is provided with a flange (301); the outer edge of the leaf spring is fixed to the inner wall of the valve body (4) by a snap ring (12), and the inner edge of the leaf spring is sleeved on the valve core (3) and connected to the flange (301).

6. The proportional flow control valve according to claim 5, characterized in that, The cantilever beam on the leaf spring includes a helical or vortex-shaped cantilever beam.

7. The proportional flow control valve according to claim 5, characterized in that, The upper surface of the flange (301) of the valve core (3) is horizontally aligned with the lower surface of the retaining ring (12).

8. A method of using a proportional flow control valve based on a double-layer annular piezoelectric ceramic stack as described in any one of claims 1 to 7, characterized in that, include: After the valve seat (8) is snapped into the nozzle (6), it is placed into the valve body (4), and the nozzle (6) is welded to the valve body (4); The valve core (3) is placed inside the valve body (4), and the end of the valve core (3) is inserted into the valve seat (8) and engages with the opening of the nozzle (6); The first elastic limiting member (7) is sleeved on the outside of the valve core (3) and pre-tightened. Place the piezoelectric ceramic drive mechanism (2) inside the valve body (4) and sleeve it on the outside of the valve core (3). Pass the nut (9) through the top of the valve core (3) and connect it to the top of the piezoelectric ceramic drive mechanism (2). Weld the nut (9) to the top of the valve core (3). The piezoelectric ceramic drive mechanism (2) and the electrode core (5) are connected by lead wires, and the valve cover (1) and the valve body (4) are sealed by locking threads; Connect the air inlet pipe (101) provided in the valve cover (1) to the air source; The electrode core (5) is connected to an external driving power supply via a lead wire. Voltage is applied to the piezoelectric ceramic driving mechanism (2) through the electrode core (5). The piezoelectric ceramic driving module is energized and displaced, which in turn drives the valve core (3) to displace.

Images