An apparatus for servo valve control chamber pressure fluctuation detection and active control

Abstract

The application discloses a device for servo valve control cavity pressure fluctuation detection and active control, which comprises a base, one side of the base is fixedly connected with a control cavity side; the base and the control cavity side have an internal cavity, a detection control unit is arranged in the internal cavity; the detection control unit comprises a first connecting part connected with the middle part of the base, the end of the first connecting part is provided with a flexible bellows ring located in the internal cavity, the end of the flexible bellows ring is connected with a detection head; the inner wall of the first connecting part is provided with a second connecting part, the detection control unit is connected with an insulating plug through the second connecting part, the end of the insulating plug is provided with a piezoelectric stack, the piezoelectric stack is in contact with the inner side surface of the detection head; the insulating plug is further provided with a wiring terminal, and the wiring terminal is connected with the piezoelectric stack. The device can replace the servo valve control cavity end cover, can actively detect the cavity pressure fluctuation, can realize active control, and improves the working performance of the servo valve.

Description

Technical Field

[0001] This invention relates to the field of vibrator technology, and more specifically, to a device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve. Background Technology

[0002] Servo valves are the core control units in electro-hydraulic servo systems, widely used in aerospace, military, marine, and machine tool industries due to their high-frequency response and rapid operation. Servo valves used in hydraulic systems are particularly susceptible to self-excited oscillations caused by pressure fluctuations. This self-excited oscillation, commonly known as whistling, is typically a high-frequency oscillation that can easily damage critical components and even cause the entire servo hydraulic system to malfunction. Currently, this problem is still under investigation in the industry, and there is no universally effective solution to completely eliminate it. Existing technologies often involve replacing the entire servo valve, which significantly increases costs and still fails to eradicate the whistling phenomenon. Summary of the Invention

[0003] The purpose of this invention is to provide a device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve. This invention can replace the end cap of the servo valve control chamber, actively detect pressure fluctuations within the chamber, and achieve active control, thereby improving the performance of the servo valve.

[0004] The technical solution of the present invention is as follows: A device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve includes a base, with a control chamber side fixedly connected to one side of the base; an internal cavity exists between the base and the control chamber side, and a detection control unit is disposed in the internal cavity; the detection control unit includes a first connecting part connected to the middle of the base, and a flexible corrugated ring located in the internal cavity is provided at the end of the first connecting part, with a detection head connected to the end of the flexible corrugated ring; a second connecting part is provided on the inner wall of the first connecting part, and an insulating plug is connected to the detection control unit via the second connecting part; a piezoelectric stack is provided at the end of the insulating plug, and the piezoelectric stack contacts the inner surface of the detection head; a terminal is also provided on the insulating plug, and the terminal is connected to the piezoelectric stack.

[0005] The aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve has an oil inlet and an oil outlet on the control chamber side.

[0006] In the aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, the base is connected to the control chamber side via multiple connecting bolts.

[0007] The aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve further includes a control detection unit base, with a partition baffle between the control detection unit base and the base.

[0008] The aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve includes a base sealing ring between the base and the partition baffle; and a detection control unit sealing ring between the partition baffle and the base of the control detection unit.

[0009] The aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve has side edges symmetrically positioned on both sides of the base of the control detection unit.

[0010] In the aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, the flexible bellows ring is composed of multiple identical, axially deformable circular rings arranged at equal intervals.

[0011] In the aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, the first connecting part is an external connecting thread; the second connecting part is an internal connecting thread.

[0012] In the aforementioned device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, the internal and external connecting threads have opposite rotation directions.

[0013] Compared with existing technologies, this invention can replace the end cap of the control chamber of a servo valve. It utilizes the force generated by the changing pressure within the internal cavity due to fluid pressure fluctuations to drive the detection head axially relative to its equilibrium position. This axial movement of the detection head simultaneously acts on the piezoelectric stack, causing it to deform axially under the force, generating an electrical signal. This signal is transmitted to an external controller via the wiring terminals to detect pressure changes within the cavity. This invention can actively detect pressure fluctuations within the cavity, thus replacing the function of a pressure sensor. Furthermore, based on the detection of pressure fluctuations, the external controller can apply control signals (such as sine waves, square waves, random waves, etc.) to the wiring terminals, driving the piezoelectric stack to move axially, which in turn drives the detection head. By actively controlling the signal as an interference source, the frequency of pressure fluctuations within the cavity is altered, interfering with the critical conditions for self-excited oscillation in the servo valve and improving its operational stability. Attached Figure Description

[0014] Figure 1 This is an external view of the device of the present invention;

[0015] Figure 2 This is a diagram of the internal structure of the device of the present invention;

[0016] Figure 3 To test the control unit structure diagram;

[0017] Figure 4 For the appearance diagram of the inspection control unit;

[0018] Figure 5This is a schematic diagram of the invention installed in the control chambers on both sides of the servo valve.

[0019] Figure Labels

[0020] 1. Base; 2. Control chamber side; 3. Partition baffle; 4. Detection and control unit; 5. Piezoelectric stack; 6. Detection and control unit sealing ring; 7. Base sealing ring; 8. Insulating plug; 9. Wiring terminal; 10. Connecting bolt; 2-1. Oil inlet; 2-2. Oil outlet; 4-1. Detection and control unit base; 4-2. Detection head; 4-3. Flexible corrugated ring; 4-4. First connecting part; 4-5. Second connecting part. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0022] Example: A device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, such as... Figure 1 and Figure 2 As shown, the device includes a base 1, with a control chamber side 2 fixedly connected to one side of the base 1. The base 1 and the control chamber side 2 are connected by six connecting bolts 10. The base 1 can be designed with different cross-sectional shapes, such as annular, rectangular, or square, depending on the shape of the pressure control chamber of the servo valve. An internal cavity exists between the base 1 and the control chamber side 2. The control chamber side 2 is provided with an oil inlet 2-1 and an oil outlet 2-2 for liquid inflow and outflow. In other embodiments, it can also be directly connected to the pressure control chamber of the servo valve, as long as the internal cavity formed by the base 1 and the control chamber side 2 is ensured. A detection and control unit 4 is provided in the internal cavity. Figure 3 As shown, the detection control unit 4 includes a first connecting part 4-4 connected to the middle of the base 1, the first connecting part 4-4 being an externally connected thread; the end of the first connecting part 4-4 is provided with a flexible corrugated ring 4-3 located in the internal cavity, and the end of the flexible corrugated ring 4-3 is connected to a detection head 4-2; the flexible corrugated ring 4-3 is composed of multiple identical axially deformable circular rings arranged at equal intervals; the detection head 4-2 has different working areas on its left and right sides under the control cavity 2, the right side being the entire circular surface, and the left side being a circular ring surface; the detection control unit 4 also includes a control detection unit base 4-1, with a partition baffle 3 between the control detection unit base 4-1 and the base 1, and the control detection unit base 4-1 pressing on the partition baffle 3 after installation. A base sealing ring 7 is provided between the base 1 and the partition baffle 3; a detection control unit sealing ring 6 is provided between the partition baffle 3 and the control detection unit base 4-1. The partition baffle 3 is used to separate the base 1 and the detection and control unit 4, and the base sealing ring 7 and the detection and control unit sealing ring 6 provided on the base 1 achieve a seal between the inside of the control cavity 2 and the outside. Figure 4 As shown, the control and detection unit base 4-1 has symmetrical side edges 4-6 on both sides, facilitating the operation of tools during installation of the detection and control unit 4. The inner wall of the first connecting part 4-4 is provided with a second connecting part 4-5, which is an internal connecting thread. The internal connecting thread and the external connecting thread have opposite rotation directions to ensure reliable connection and sealing during installation. The detection and control unit 4 is connected to an insulating plug 8 via the second connecting part 4-5. The end of the insulating plug 8 is provided with a piezoelectric stack 5 (a load consisting of several piezoelectric ceramic plates connected in physical series, electrical parallel, or series connection is called a piezoelectric stack, which can be used in fields such as micro-positioning, valve control, vibration damping, and sound wave generation; it is a conventional technology). The piezoelectric stack 5 is in contact with the inner surface of the detection head 4-2. The insulating plug 8 is also provided with a terminal 9, which is connected to the piezoelectric stack 5 via a lead wire. The terminal 9 is used for connecting an external controller.

[0023] During installation, the detection control unit 4 is first mounted on the partition baffle 3 with the detection control unit sealing ring 6; then it is tightened onto the base 1 with the base sealing ring 7; then, the piezoelectric stack 4 and its terminals 9 are passed through the insulating plug 8 and fixed; next, the insulating plug 8 with the piezoelectric stack 4 is tightened onto the detection control unit 4 and fixed; finally, the assembled base 1 is connected and fixed to the control cavity side 2 by the connecting bolts 10. To increase sealing, matching sealing elements can be placed directly on the base 1 and the control cavity side 2.

[0024] Working principle: such as Figure 5 As shown, when the device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve is installed in the left control chamber x and the right control chamber y of the servo valve 11, it will generate a force F = p(A) based on the pressure generated by the pressure fluctuations within the chambers acting on the detection head 4-2. 圆 -A 环 ), where p is the intracavitary pressure, A 圆 It is the area of ​​the end face of the detection head 4-2, A 环 It is the annular area on the back side of the detection head 4-2.

[0025] During signal detection: The pressure inside the cavity changes with the fluctuation of the fluid pressure chamber, causing the detection head 4-2 to move axially relative to the equilibrium position. This axial movement of the detection head simultaneously acts on the piezoelectric stack 5, causing it to undergo axial displacement deformation under the force, generating an electrical signal. This signal is transmitted to an external controller via terminal 9 for detecting pressure changes inside the cavity.

[0026] Active control process: The control signal (such as sine wave, square wave, random wave, etc.) of the external controller is applied to the terminal 9 to drive the piezoelectric stack 5 to generate axial movement, which in turn drives the detection head 4-2 to move. As an interference source, it changes the frequency of pressure fluctuation in the cavity, interferes with the critical condition for the servo valve to generate self-excited oscillation, and improves the working stability of the servo valve.

[0027] In summary, this invention can replace the end cap of the control chamber in a servo valve. It not only actively detects pressure fluctuations within the chamber, replacing the function of a pressure sensor, but also, based on the detection of pressure fluctuations, achieves active control by switching the controller's functions to change the frequency of pressure fluctuations within the control chamber. This disrupts the critical condition for high-frequency oscillation in the servo valve, significantly improving its performance. This invention can be used not only in servo valves with two control chambers, such as nozzle-baffle servo valves and jet pipe servo valves, but also in two-dimensional servo valves with a single control chamber.

Claims

1. A device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve, characterized in that: The system includes a base (1), with a control cavity side (2) fixedly connected to one side of the base (1); an internal cavity exists between the base (1) and the control cavity side (2), and a detection control unit (4) is disposed in the internal cavity; the detection control unit (4) includes a first connecting part (4-4) connected to the middle of the base (1), and a flexible corrugated ring (4-3) located in the internal cavity is provided at the end of the first connecting part (4-4), and a detection head (4-2) is connected to the end of the flexible corrugated ring (4-3); a second connecting part is provided on the inner wall of the first connecting part (4-4). (4-5) The detection control unit (4) is connected to an insulating plug (8) via a second connecting part (4-5). The end of the insulating plug (8) is provided with a piezoelectric stack (5), which is in contact with the inner side of the detection head (4-2). The insulating plug (8) is also provided with a wiring terminal (9), which is connected to the piezoelectric stack (5). The detection control unit (4) also includes a control detection unit base (4-1), and a partition baffle (3) is provided between the control detection unit base (4-1) and the base (1).

2. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: The control chamber side (2) has an oil inlet (2-1) and an oil outlet (2-2).

3. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: The base (1) is connected to the control cavity side (2) by a number of connecting bolts (10).

4. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: A base sealing ring (7) is provided between the base (1) and the partition baffle (3); a detection control unit sealing ring (6) is provided between the partition baffle (3) and the control detection unit base (4-1).

5. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: The control and detection unit base (4-1) has side edges (4-6) at symmetrical positions on both sides.

6. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: The flexible corrugated ring (4-3) is composed of multiple identical axially deformable rings arranged at equal intervals.

7. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 1, characterized in that: The first connecting part (4-4) is an external connecting thread; the second connecting part (4-5) is an internal connecting thread.

8. The device for detecting and actively controlling pressure fluctuations in the control chamber of a servo valve according to claim 7, characterized in that: The internal and external connecting threads have opposite directions of rotation.

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