Piezoelectric double-nozzle baffle electro-hydraulic servo valve

Abstract

The application discloses a piezoelectric double-nozzle baffle electro-hydraulic servo valve, which comprises a valve seat, control oil path interfaces, oil return ports, high-power oil path interfaces, first hydraulic cylinder interfaces and second hydraulic cylinder interfaces are formed above the valve seat; a valve sleeve mounting seat is installed at the center position of the valve seat, side end covers are arranged on the two sides of the valve sleeve mounting seat; a baffle fixing seat is installed above the valve sleeve mounting seat, a piezoelectric baffle assembly is installed at the center of the baffle fixing seat; the piezoelectric baffle assembly comprises a baffle, a piezoelectric sheet and a strain sheet; a valve sleeve is installed inside the valve sleeve mounting seat, and a spool valve is arranged inside the valve sleeve. The piezoelectric double-nozzle baffle electro-hydraulic servo valve has the characteristics of high frequency response, no electromagnetic interference and the like, can realize the characteristics of high frequency response, large flow and low power consumption of the electro-hydraulic servo valve, can meet the use requirements of special application scenarios and has high application value.

Description

Technical Field

[0001] This invention relates to the field of hydraulic servo control technology, and in particular to a piezoelectric dual-nozzle baffle electro-hydraulic servo valve. Background Technology

[0002] Electro-hydraulic servo systems are indispensable equipment in the aerospace and defense industries, and are widely used in scenarios requiring high control precision and high output power. As the core component of an electro-hydraulic servo system, the electro-hydraulic servo valve converts low-power control signals into high-power hydraulic output; its performance and reliability have a significant impact on the entire servo system.

[0003] Traditional electro-hydraulic servo valves using a baffle assembly with a Bourdon tube and feedback rod are driven by a torque motor. When the coil is energized, the armature rotates under the influence of a magnetic field, which in turn pushes the baffle to rotate in the same direction, changing the position of the spool valve and generating high-power output. Because its working principle relies on an electric field generating a magnetic field, it suffers from significant power consumption and poor anti-interference capabilities, making it difficult to meet the practical requirements of applications in strong electromagnetic environments. Furthermore, the slender structure of the feedback rod and its large inertia hinder further improvements in the high-frequency response characteristics of the electro-hydraulic servo valve.

[0004] However, using a piezoelectric stack to directly drive the spool valve core results in an excessively large overall size of the servo valve because the spool valve core requires a large displacement while the piezoelectric stack outputs a small displacement. Summary of the Invention

[0005] The purpose of this invention is to provide a piezoelectric dual-nozzle baffle electro-hydraulic servo valve, which utilizes the high-frequency response and lack of electromagnetic interference of piezoelectric ceramics to achieve the characteristics of high-frequency response, large flow rate, and low power consumption of the electro-hydraulic servo valve, in order to meet the usage requirements of special application scenarios.

[0006] To achieve the above objectives, the present invention provides a piezoelectric dual-nozzle baffle electro-hydraulic servo valve, comprising a valve seat, wherein a control oil circuit interface, a return oil port, a high-power oil circuit interface, a first hydraulic cylinder interface, and a second hydraulic cylinder interface are respectively provided on the upper part of the valve seat; a valve sleeve mounting seat is installed at the center of the valve seat, and side end caps are provided on both sides of the valve sleeve mounting seat; a baffle fixing seat is installed above the valve sleeve mounting seat, and an opening is provided at the center of the baffle fixing seat and a piezoelectric baffle assembly is installed thereon; the piezoelectric baffle assembly includes a baffle, a piezoelectric element, and a strain gauge.

[0007] A slide valve is installed inside the valve sleeve mounting seat. The slide valve includes a valve sleeve and a valve core, and the valve core is installed inside the valve sleeve. A baffle movable cavity is provided at the center of the valve sleeve mounting seat, located above the valve sleeve. The baffle passes into the baffle movable cavity. The lower part of the baffle movable cavity communicates with the inside of the valve sleeve and forms a return oil cavity. The return oil cavity is connected to the return oil port through a return oil channel.

[0008] A first nozzle and a second nozzle are symmetrically installed on the left and right sides of the baffle movable cavity, respectively. The first nozzle is connected to the first throttling screw through a pipeline, and the second nozzle is connected to the second throttling screw through a pipeline. The control oil circuit interface is connected to the first throttling screw through the left side of the control oil channel and is diverted to the left side of the valve sleeve. The control oil circuit interface is connected to the second throttling screw through the right side of the control oil channel and is diverted to the right side of the valve sleeve.

[0009] The valve sleeve has a first hydraulic cylinder interface connection cavity on the left side and a second hydraulic cylinder interface connection cavity on the right side, with the valve core blocking the middle section. The first hydraulic cylinder interface connection cavity is connected to the first hydraulic cylinder interface through a pipeline, and the second hydraulic cylinder interface connection cavity is connected to the second hydraulic cylinder interface through a pipeline. The lower sides of both sides of the valve core are connected to high-power oil pipelines, and the outside of the high-power oil pipelines is connected to the high-power oil circuit interface.

[0010] Preferably, the baffle is the substrate of the piezoelectric baffle assembly, the piezoelectric sheets are symmetrically attached to both sides of the baffle, and the strain gauges are attached to the outer side of the piezoelectric sheets.

[0011] Preferably, the strain gauge, piezoelectric sheet, and baffle are all fixed together with structural adhesive.

[0012] Preferably, the control oil passage enters the interior of the slide valve from the side end caps on both the left and right sides.

[0013] Preferably, the piezoelectric baffle assembly is fixed above the baffle mounting base using M4 screws.

[0014] Preferably, the control oil channel, return oil channel, and high-power oil pipeline are all connected to the side wall of the valve seat and sealed with sealing screws.

[0015] Preferably, mounting grooves are provided on both the left and right sides of the valve seat.

[0016] Therefore, the advantages of the piezoelectric dual-nozzle baffle electro-hydraulic servo valve of the present invention compared with the prior art are as follows:

[0017] (1) By adopting a piezoelectric baffle assembly, the electro-hydraulic servo valve does not need to be converted by electromagnetic field, which improves the anti-interference strength of the electro-hydraulic servo valve.

[0018] (2) By controlling the magnitude of the electric field strength acting on the piezoelectric sheet, the baffle substrate is deformed, and the distance of the baffle from its original position is precisely controlled. At the same time, strain gauges are used to detect the bending deformation of the baffle substrate in real time, and closed-loop control is realized from inside the electro-hydraulic servo valve to achieve high-precision output of the electro-hydraulic servo valve.

[0019] (3) It has a simple structure and is easy to promote and use.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a three-dimensional cross-sectional structural schematic diagram of a piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to the present invention;

[0022] Figure 2 This is a top view schematic diagram of a piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to the present invention;

[0023] Figure 3 This is a front cross-sectional view of a piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to the present invention.

[0024] Figure 4 This is a schematic diagram of the piezoelectric baffle assembly structure of a piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to the present invention;

[0025] Figure 5 This is a schematic diagram of the deformation of the piezoelectric baffle assembly of a piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to the present invention.

[0026] Figure Labels

[0027] 1. Valve seat; 2. Control oil circuit interface; 21. Control oil passage; 3. Side end cover; 4. Spool valve; 5. Valve sleeve; 51. Valve core; 6. Valve sleeve mounting seat; 7. Oil return port; 8. Sealing screw; 9. High-power oil circuit interface; 91. High-power oil pipeline; 10. Baffle fixing seat; 11. Piezoelectric baffle assembly; 111. Piezoelectric element; 112. Strain gauge; 113. Structural adhesive; 114. Baffle; 12. First nozzle; 13. First throttling screw; 131. Second throttling screw; 14. First hydraulic cylinder interface; 141. First hydraulic cylinder interface connection cavity; 15. Second hydraulic cylinder interface; 151. Second hydraulic cylinder interface connection cavity; 16. Second nozzle; 17. Baffle movable cavity; 18. Oil return cavity; 19. Mounting groove. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] Example 1

[0031] like Figure 1 , Figure 2 , Figure 3 As shown, this invention provides a piezoelectric dual-nozzle baffle electro-hydraulic servo valve, including a valve seat 1. Mounting grooves 19 are provided on both the left and right sides of the valve seat 1 for easy fixing. A control oil circuit interface 2, a return oil port 7, a high-power oil circuit interface 9, a first hydraulic cylinder interface 14, and a second hydraulic cylinder interface 15 are respectively provided on the top of the valve seat 1. A valve sleeve mounting seat 6 is installed at the center of the valve seat 1. Side end caps 3 are provided on both sides of the valve sleeve mounting seat 6, and both side end caps 3 can be opened to facilitate inspection and maintenance of the internal structure of the valve sleeve mounting seat 6.

[0032] A baffle mounting base 10 is installed above the valve sleeve mounting base 6. An opening is provided at the center of the baffle mounting base 10, and a piezoelectric baffle assembly 11 is installed thereon. The piezoelectric baffle assembly 11 is fixed to the baffle mounting base 10 with M4 screws. Figure 4 As shown, the piezoelectric baffle assembly 11 includes a piezoelectric sheet 111, a strain gauge 112, and a baffle 114. The baffle 114 is the substrate of the piezoelectric baffle assembly 11. The piezoelectric sheet 111 is symmetrically attached to both sides of the baffle 114, and the strain gauge 112 is attached to the outside of the piezoelectric sheet 111. The strain gauge 112 can detect the deformation of the baffle 114. The strain gauge 112, the piezoelectric sheet 111, and the baffle 114 are all fixed together with structural adhesive 113.

[0033] A slide valve 4 is installed inside the valve sleeve mounting seat 6. The slide valve 4 is equipped with a valve sleeve 5 and a valve core 51. The valve core 51 is installed inside the valve sleeve 5 and can slide left and right inside the valve sleeve 5.

[0034] A baffle movable cavity 17 is provided at the center of the valve sleeve mounting seat 6, located above the valve sleeve 5, and a baffle 114 passes into the baffle movable cavity 17. The lower part of the baffle movable cavity 17 communicates with the interior of the valve sleeve 5 and forms a return oil cavity 18, which is connected to the return oil port 7 through a return oil channel. A first nozzle 12 and a second nozzle 16 are symmetrically installed on the left and right sides of the baffle movable cavity 17, respectively. The first nozzle 12 is connected to the first throttle screw 13 through a control oil channel 21, and the second nozzle 16 is connected to the second throttle screw 131 through a control oil channel 21.

[0035] The control oil circuit interface 2 enters the slide valve 4 from the side end caps 3 at both ends through the left and right sides of the control oil channel 21. The control oil circuit interface 2 is connected to the first throttle screw 13 through the left side of the control oil channel 21 and is diverted to the left end of the valve core 51. The control oil circuit interface 2 is connected to the second throttle screw 131 through the right side of the control oil channel 21 and is diverted to the right end of the valve core 51.

[0036] The valve sleeve 5 has a first hydraulic cylinder interface connection cavity 141 on the left and a second hydraulic cylinder interface connection cavity 151 on the right, with the valve core 51 acting as a barrier in the middle. The first hydraulic cylinder interface connection cavity 141 is connected to the first hydraulic cylinder interface 14 via a pipeline, and the second hydraulic cylinder interface connection cavity 151 is connected to the second hydraulic cylinder interface 15 via a pipeline. The lower sides of both sides of the valve core 51 are connected to the high-power oil supply pipeline 91, and the outside of the high-power oil supply pipeline 91 is connected to the high-power oil circuit interface 9. The control oil passage 21, the return oil passage, and the high-power oil supply pipeline 91 are all connected to the side wall of the valve seat 1 and sealed with sealing screws 8.

[0037] The working principle of the piezoelectric dual-nozzle baffle electro-hydraulic servo valve of the present invention is as follows: After the present invention is installed, the end baffle 114 of the piezoelectric baffle assembly 11 is located at the center of the opening of the valve sleeve mounting seat 6. The control hydraulic oil is diverted on the left and right sides of the control oil channel 21 through the control oil interface 2 before reaching the first throttle screw 13 and the second throttle screw 131 respectively. Part of the hydraulic oil on the left side enters the first throttle screw 13, and part of it reaches the left end of the valve core 51. The hydraulic oil entering the first throttle screw 13 further enters the first nozzle 12 and is sprayed out towards the baffle 114 under pressure. Similarly, part of the hydraulic oil on the right side enters the second throttle screw 131, and part of it reaches the right end of the valve core 51. The hydraulic oil entering the second throttle screw 131 further enters the second nozzle 16 and is sprayed out towards the baffle 114 under pressure. The left and right sides are symmetrically designed.

[0038] When no voltage is applied to the baffle 114, the baffle 114 is in the center position of the two nozzles, and the gap between the baffle 114 and the left and right nozzles is the same, that is, the hydraulic pressure acting on the two ends of the valve core 51 is the same, and the slide valve 4 is closed.

[0039] When a voltage is applied to the piezoelectric element 111 on the right side of the baffle 114, due to the inverse piezoelectric effect, the piezoelectric element 111 elongates in the thickness direction and contracts in the length direction. The strain during the contraction in the length direction is:

[0040] Δl-Ed 31 (1)

[0041]

[0042] In the formula: Δl is the strain along the length of the piezoelectric element; E is the electric field strength; d 31 U is the piezoelectric constant; U is the voltage applied to the piezoelectric element; t is the thickness of the piezoelectric element.

[0043] Because one side of the piezoelectric element 111 is fixed to the baffle 114, its contraction along one length causes the baffle 114 to bend to the right. Figure 5 As shown. At this time, the gap between the baffle 114 and the second nozzle 16 decreases, and the gap between the baffle 114 and the first nozzle 12 increases, causing the pressure on the right end face of the valve core 51 of the slide valve 4 to be greater than the pressure on the left end face. The valve core 51 of the slide valve 4 moves to the left, so that the high-power oil pipeline 91 is connected to the first hydraulic cylinder interface connection chamber 141, and the second hydraulic cylinder interface connection chamber 151 is connected to the return oil chamber 18, so that the oil pump supplies oil to the hydraulic cylinder through the first hydraulic cylinder interface 14, and at the same time returns oil through the second hydraulic cylinder interface 15.

[0044] Similarly, when the voltage of the piezoelectric element 111 on the left side of the baffle 114 is given, the valve core 51 of the slide valve 4 moves to the right, so that the high-power oil pipeline 91 is connected to the second hydraulic cylinder interface connection chamber 151, and the first hydraulic cylinder interface connection chamber 141 is connected to the return oil chamber 18, so that the oil pump supplies oil to the hydraulic cylinder through the second hydraulic cylinder interface 15, and at the same time returns oil through the first hydraulic cylinder interface 14.

[0045] The use of piezoelectric element 111 provides fast dynamic response and high positioning accuracy, which can effectively improve the anti-interference ability and dynamic response frequency of electro-hydraulic servo valves and enhance their application scenarios.

[0046] Therefore, the present invention adopts the above-mentioned piezoelectric dual-nozzle baffle electro-hydraulic servo valve, which utilizes the high-frequency response and lack of electromagnetic interference of piezoelectric ceramics to achieve the high-frequency response, large flow rate and low power consumption characteristics of electro-hydraulic servo valve, which can meet the usage requirements of special application scenarios and has high application value.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A piezoelectric dual-nozzle baffle electro-hydraulic servo valve, characterized in that: The device includes a valve seat, on which a control oil circuit interface, a return oil port, a high-power oil circuit interface, a first hydraulic cylinder interface, and a second hydraulic cylinder interface are respectively opened; a valve sleeve mounting seat is installed at the center of the valve seat, and side end caps are provided on both sides of the valve sleeve mounting seat; a baffle fixing seat is installed above the valve sleeve mounting seat, and an opening is provided at the center of the baffle fixing seat and a piezoelectric baffle assembly is installed; the piezoelectric baffle assembly includes a baffle, a piezoelectric element, and a strain gauge; A slide valve is installed inside the valve sleeve mounting seat. The slide valve includes a valve sleeve and a valve core, and the valve core is installed inside the valve sleeve. A baffle movable cavity is provided at the center of the valve sleeve mounting seat, located above the valve sleeve. The baffle passes into the baffle movable cavity. The lower part of the baffle movable cavity communicates with the inside of the valve sleeve and forms a return oil cavity. The return oil cavity is connected to the return oil port through a return oil channel. A first nozzle and a second nozzle are symmetrically installed on the left and right sides of the baffle movable cavity, respectively. The first nozzle is connected to the first throttling screw through a pipeline, and the second nozzle is connected to the second throttling screw through a pipeline. The control oil circuit interface is connected to the first throttling screw through the left side of the control oil channel and is diverted to the left side of the valve sleeve. The control oil circuit interface is connected to the second throttling screw through the right side of the control oil channel and is diverted to the right side of the valve sleeve. The valve sleeve has a first hydraulic cylinder interface connection cavity on the left side and a second hydraulic cylinder interface connection cavity on the right side, with the valve core blocking the middle section. The first hydraulic cylinder interface connection cavity is connected to the first hydraulic cylinder interface through a pipeline, and the second hydraulic cylinder interface connection cavity is connected to the second hydraulic cylinder interface through a pipeline. The lower sides of both sides of the valve core are connected to high-power oil pipelines, and the outside of the high-power oil pipelines is connected to the high-power oil circuit interface.

2. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 1, characterized in that: The baffle is the substrate of the piezoelectric baffle assembly, the piezoelectric sheets are symmetrically attached to both sides of the baffle, and the strain gauges are attached to the outer side of the piezoelectric sheets.

3. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 2, characterized in that: The strain gauge, piezoelectric plate, and baffle are all fixed together with structural adhesive.

4. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 1, characterized in that: The control oil passage enters the slide valve from the side end caps on both the left and right sides.

5. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 1, characterized in that: The piezoelectric baffle assembly is fixed above the baffle mounting base using M4 screws.

6. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 1, characterized in that: The control oil channel, return oil channel, and high-power oil pipeline are all connected to the side wall of the valve seat and sealed with sealing screws.

7. The piezoelectric dual-nozzle baffle electro-hydraulic servo valve according to claim 1, characterized in that: The valve seat has mounting grooves on both its left and right sides.

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