A broadband high-frequency flutter differential pressure wave excitation device

Abstract

The present invention provides a wide-band high-frequency flutter differential pressure wave excitation device, which belongs to the field of hydraulic control technology and realizes multi-frequency low-distortion periodic flutter excitation pressure waves within a wide-band range (1 to 2000 / 10000 Hz) in the hydraulic system. The present invention includes two pressure excitation chambers and an electromagnetic excitation actuator to provide differential hydraulic excitation waves for the two chambers of the hydraulic cylinder respectively. The pressure excitation chamber is a piston structure, which can achieve relative amplification of high-frequency micro-displacement and is driven by an electric excitation actuator. The electric excitation actuator selects Terfenol-D magnetostrictive material as the driving source. The overall structure of the equipment of the present invention is simple and easy to use. It has the ability to linearly adjust the output hydraulic flow and has strong anti-pollution ability as a whole. Most of the key performance components designed are standard parts, which greatly reduces the manufacturing difficulty.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic control technology and relates to a wide-band high-frequency vibration differential pressure wave excitation device, and in particular to a high-frequency vibration exciter for generating the excitation of high-frequency pressure waves inside a hydraulic cylinder, thereby realizing the differential output of periodic superimposed waves of different waveforms, amplitudes, and frequencies. Background Art

[0002] Frictional nonlinearity in hydraulic cylinders is a major obstacle to achieving high-precision servo control. Nonlinear friction severely impacts the system's operational smoothness and tracking accuracy, leading to system "creep," increased control errors, and significant dead zone characteristics, limiting system performance under complex operating conditions. Based on current research findings, flutter wave friction reduction technology is an efficient and easy-to-implement friction reduction method that effectively suppresses the effects of nonlinear coupled friction. By eliminating the directionality of friction, flutter waves ensure continuous motion of the hydraulic cylinder piston, avoiding the effects of static friction and thus improving system performance.

[0003] However, conventional dithering methods are currently limited to control valve performance. Non-sinusoidal signals such as triangular, square, and sawtooth waves are composed of a series of discrete frequency components, ranging from low to high frequencies. In actual control processes, due to the narrow bandwidth of the control valve, when the excitation signal is input, the signal amplitude gradually decays to zero as the dither frequency increases. Frequency decay and loss often lead to side effects such as noise and jitter. Currently available research focuses on dither frequency within 150 Hz, lacking more systematic research on the waveform and amplitude of high-frequency dither excitation. For example, Chinese invention patent CN103174702A develops a targeted ultrasonic dithering method for piston dithering, installing a piezoelectric ceramic device on the piston surface as a dither excitation source. However, its application is also quite limited, making it difficult to fully realize the expected effects in high-pressure hydraulic equipment, especially in service equipment.

[0004] Therefore, developing a high-frequency flutter actuator suitable for high-pressure hydraulic systems is of great application and research significance. Because traditional mechanical and motor-driven methods are no longer able to power high-frequency flutter actuators, and given the high frequency and small amplitude characteristics of flutter signals, new drive methods and control strategies with better performance are needed. Summary of the Invention

[0005] To address the challenges of existing technologies, the present invention provides a broadband, high-frequency dither differential pressure wave excitation device suitable for hydraulic systems. This device implements differential drive control of the hydraulic system's dither friction-reducing pressure waves in the high-frequency band (0-2000 / 10000 Hz), thus filling the gap in high-frequency hydraulic excitation equipment. This new device features a simple structure, strong anti-fouling capabilities, and stable reliability.

[0006] In order to achieve the above object, the technical solution adopted in the present invention is:

[0007] A broadband, high-frequency dither differential pressure wave excitation device, characterized by achieving multi-frequency, low-distortion, periodic dither excitation pressure waves within a broadband range (1-2000 / 10000 Hz) in a hydraulic system, is described. The device features a bilaterally symmetrical structure, comprising an upper hydraulic housing 1, a lower actuating housing 2, a support end cap 23 at the bottom of the actuating housing 2, two pressure chambers within the hydraulic housing 1, actuating housing 2, and support end cap 23, and two electromagnetic excitation actuators, respectively, to provide differential hydraulic excitation waves for the two chambers of the hydraulic cylinder. The two pressure chambers comprise a left pressure chamber and a right pressure chamber. The left electromagnetic excitation actuator is mounted in the left pressure chamber, while the right electromagnetic excitation actuator is mounted in the right pressure chamber.

[0008] The oil pressure housing 1 is sealed against the top of the actuator housing 2, while the bottom of the actuator housing 2 is sealed against the support end cap 23. The two pressure chambers are composed of the left and right cavities within the oil pressure housing 1 and the actuator housing 2, respectively. The pressure chamber within the oil pressure housing 1 includes two symmetrically arranged left and right pressure excitation chambers, while the pressure chamber within the actuator housing 2 includes two symmetrically arranged left and right motion chambers. The left pressure chamber is composed of a left pressure excitation chamber and a left motion chamber, while the right pressure chamber is composed of a right pressure excitation chamber and a right motion chamber.

[0009] Furthermore, the hydraulic housing 1 features a symmetrical dual-cavity structure. The left pressure excitation chamber within the housing is described as an example. The left pressure excitation chamber is a trapezoidal cylindrical through-hole extending through the hydraulic housing 1, longitudinally divided into two cylindrical cavities of different diameters. The upper cylindrical cavity has a relatively small diameter and serves as the connection to the oil output interface. A protruding, integrated annular interface is designed at the top of the cylindrical cavity. The external surface of the annular interface is standardly threaded, facilitating the sealing of external oil pipelines. The lower cylindrical cavity has a relatively large diameter, and a vent is reserved in the shoulder connecting to the upper smaller-diameter cylindrical cavity. Specifically, it is located at the top of the left shoulder of the left pressure excitation chamber. This vent is threadedly connected to the left cone-valve exhaust valve 3, facilitating the exhaust of the left pressure excitation chamber. The lower cylindrical cavity houses the actuating piston structure of the left electromagnetic excitation actuator. This actuating piston structure includes a left flutter excitation head 4, a left output rod 5, a left preload spring 6, and a left flutter seal assembly 11.

[0010] The top of the actuating piston structure is a cylindrical left flutter excitation head 4 with a circumferential groove. This left flutter excitation head 4 is connected to the inner wall of the left cavity of the oil pressure housing 1 in a multi-stage sealed manner via a left flutter seal ring assembly 11. The bottom center of the left flutter excitation head 4 is connected to the left output rod 5. This left output rod 5 is a trapezoidal metal connecting rod with an inverted T-shaped structure. The upper portion is a small-diameter metal round rod with a threaded top screw that is fixed to the bottom center threaded hole of the left flutter excitation head 4. The bottom portion is a large-diameter rod cap that extends into the left cavity inside the actuating housing 2. The middle rod body of the left output rod 5 is sheathed with a left preload spring 6. The bottom of the left preload spring 6 is pressed and fixed to the upper surface of the bottom rod cap of the left output rod 5. The top of the left preload spring 6 is fixed to the shoulder in the left motion cavity inside the actuating housing 2. The specific fixing position is detailed below.

[0011] The two independent motion chambers inside the actuating housing 2 are designed with a left-right symmetrical structure. Taking the left motion chamber as an example, the left motion chamber is a through hole that runs through the actuating housing 2. It can be divided into three cylindrical cavities of different diameters in the longitudinal direction. After installation, the overall position is coaxially arranged longitudinally with the left pressure excitation chamber in the oil pressure housing 1. Among them, the diameter of the cylindrical cavity in the upper part of the left motion chamber is smaller than the minimum diameter of the cavity in the oil pressure housing 1, the diameter of the cylindrical cavity in the middle part is slightly larger than the maximum diameter of the cavity in the oil pressure housing 1, and the diameter of the cylindrical cavity in the lower part is the largest. The interior of the upper part of the cavity of the left motion chamber is the middle part of the left output rod 5, which is used to realize the rigid motion connection between the bottom rod cap of the left output rod 5 and the top left vibration excitation head 4; the interior of the middle part of the cavity of the left motion chamber is the bottom rod cap part of the left output rod 5, which is used to realize the motion guide space of the left output rod 5. The convex transition surface between the upper and middle portions of the left motion chamber serves as the compression and fixing location for the top of the left preload spring 6, enabling the downward rebound preload of the left output rod 5. The lower cavity of the left motion chamber houses the electromagnetic excitation structure of the left electromagnetic excitation actuator, which includes a left permanent magnet assembly 7, a left excitation coil 8, a left Terfenol-D rod (magnetostrictive material) 9, and a left strain gauge assembly 10.

[0012] The electromagnetic excitation structure is an annular multi-layer cylindrical structure, comprising, from the inside out, the innermost layer of the left Terfenol-D rod (magnetostrictive material) 9, the left strain gauge group 10, the left excitation coil 8, and the left permanent magnet group 7. The left strain gauge group 10 is glued to the outer surface of the left Terfenol-D rod 9, while the left excitation coil 8 and the left permanent magnet group 7 are fixed to the inner wall of the lower cavity of the left motion chamber. Furthermore, the excitation external circuit wire of the left excitation coil 8 is led out through an external through hole on the left side of the inner wall of the lower cavity of the left motion chamber. After installation, the external through hole is glued and sealed.

[0013] The right electromagnetic actuator utilizes the same structure, including a right cone-valve exhaust valve 12, a right dither actuator head 13, a right output rod 14, a right preload spring 15, a right permanent magnet assembly 16, a right excitation coil 17, a right Terfenol-D rod 18, a right strain gauge assembly 19, and a right dither seal ring assembly 20. These components are connected and mounted symmetrically to the left electromagnetic actuator, forming a controllable, retractable hydraulic piston with upper and lower seals, and their detailed description is omitted here.

[0014] Furthermore, the lower end face of the oil pressure housing 1 is sealed and fixed to the upper end face of the actuating housing 2 through the housing sealing gasket 22 under the pressure of the housing fixing screw group 21; the lower end face of the actuating housing 2 is sealed and fixed to the upper end face of the supporting end cover 23 through the end cover sealing gasket 25 under the pressure of the end cover fixing screw group 24.

[0015] A method for using a broadband, high-frequency dither differential pressure wave excitation device includes the following steps: inputting different externally controlled (differential) current signals into the left excitation coil 8 and the right excitation coil 17, generating different magnetic field response changes at the positions of the left Terfenol-D rod 9 and the right Terfenol-D rod 18, respectively. Under the influence of the magnetic field changes, the left Terfenol-D rod 9 and the right Terfenol-D rod 18 perform high-frequency expansion and contraction in response to the external control signals. The left Terfenol-D rod 9 drives the left output rod 5, which in turn drives the left dither excitation head 4 in vertical motion, while the right Terfenol-D rod 18 drives the right output rod 14, which in turn drives the right dither excitation head 13 in vertical motion. This results in high-frequency piston motion within the left and right chambers of the hydraulic housing 1, generating a corresponding (differential) pressure wave output. The left and right pressure chambers are connected to the two side chambers of the hydraulic cylinder via oil pipelines, respectively, to achieve high-frequency dither drive control of the hydraulic cylinder piston. The motion state of the Terfenol-D rod is monitored and fed back in real time by the left strain gauge group 10 and the right strain gauge group 19 to achieve higher precision vibration motion control.

[0016] The effects and benefits of the present invention are:

[0017] (1) The present invention designs a symmetrical bidirectional synchronous drive structure, which can provide high-frequency differential vibration pressure waves for hydraulic cylinder equipment, thereby meeting the high-frequency vibration friction reduction conditions that are difficult to achieve with existing hydraulic equipment in a simpler way, while obtaining higher output power.

[0018] (2) The driving source of the vibrator selected in the present invention is Terfenol-D magnetostrictive material, which has the advantages of high compressive strength, high power, and large expansion coefficient. Combined with the designed symmetrical bidirectional piston motion form pressure excitation chamber, it can cleverly achieve relative amplification of micro-displacement.

[0019] (3) The overall structure of the device of the present invention is simple and clear, the design is detailed, and it has the ability to linearly adjust the output hydraulic flow. It has strong anti-pollution ability as a whole, and most of the key performance components designed are selected from standard parts, which greatly reduces the manufacturing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of the overall structure of a new broadband high-frequency flutter differential pressure wave excitation device.

[0021] Figure 2 This is an installation example diagram of a new broadband high-frequency flutter differential pressure wave excitation device.

[0022] In the figure: 1 hydraulic housing, 2 actuator housing, 3 left cone valve type exhaust valve, 4 left vibration excitation head, 5 left output rod, 6 left preload spring, 7 left permanent magnet group, 8 left excitation coil, 9 left Terfenol-D rod, 10 left strain gauge group, 11 left vibration sealing ring group, 12 right cone valve type exhaust valve, 13 right vibration excitation head, 14 right output rod, 15 right preload spring, 16 right permanent magnet group, 17 right excitation coil, 18 right Terfenol-D rod, 19 right strain gauge group, 20 right vibration sealing ring group, 21 housing fixing screw group, 22 housing sealing gasket, 23 support end cover, 24 end cover fixing screw group, 25 end cover sealing gasket, 26 hydraulic cylinder, 27 left oil inlet, 28 right oil inlet, 29 left vibration oil circuit, 30 right vibration oil circuit. DETAILED DESCRIPTION

[0023] The specific implementation of the present invention is described in detail below in conjunction with the technical solutions and drawings.

[0024] A broadband, high-frequency dither differential pressure wave excitation device is described. The overall design of the device is bilaterally symmetrical, comprising an upper hydraulic housing 1, a lower actuating housing 2, a support end cap 23 at the bottom of the actuating housing 2, two pressure chambers within the hydraulic housing 1, the actuating housing 2, and the support end cap 23, and two electromagnetic excitation actuators, respectively, to provide differential hydraulic excitation waves for the two chambers of the hydraulic cylinder. The two pressure chambers include a left pressure chamber and a right pressure chamber. The left electromagnetic excitation actuator is installed in the left pressure chamber, and the right electromagnetic excitation actuator is installed in the right pressure chamber.

[0025] The oil pressure housing 1 is sealed to the top of the actuator housing 2, and the bottom of the actuator housing 2 is sealed to the support end cover 23. Specifically, the lower end face of the oil pressure housing 1 is sealed and fixed to the upper end face of the actuator housing 2 via the housing gasket 22 under the pressure of the housing fixing screw group 21; the lower end face of the actuator housing 2 is sealed and fixed to the upper end face of the support end cover 23 via the end cover gasket 25 under the pressure of the end cover fixing screw group 24. The two pressure chambers are composed of the left and right cavities inside the oil pressure housing 1 and the actuator housing 2, respectively. The pressure chamber inside the oil pressure housing 1 includes two symmetrically arranged left and right pressure excitation chambers, and the pressure chamber inside the actuator housing 2 includes two symmetrically arranged left and right motion chambers. The left pressure chamber is composed of a left pressure excitation chamber and a left motion chamber, and the right pressure chamber is composed of a right pressure excitation chamber and a right motion chamber.

[0026] The hydraulic housing 1 has a symmetrical dual-cavity structure. The left pressure excitation chamber within is used as an example for description. The left pressure excitation chamber is a trapezoidal cylindrical through-hole extending through the hydraulic housing 1, longitudinally divided into two cylindrical cavities of different diameters. The upper cylindrical cavity has a relatively small diameter and serves as the connection to the oil output interface. A protruding, integrated annular interface is designed at the top of the cylindrical cavity. The external surface of the annular interface is standardly threaded, facilitating the sealing of external oil pipelines. The lower cylindrical cavity has a relatively large diameter, and a vent is reserved in the shoulder connecting to the upper smaller-diameter cylindrical cavity. Specifically, it is located at the top of the left shoulder of the left pressure excitation chamber. This vent is threadedly connected to the left cone-valve exhaust valve 3, facilitating the exhaust of the left pressure excitation chamber. The lower cylindrical cavity houses the actuating piston structure of the left electromagnetic excitation actuator. This actuating piston structure includes a left flutter excitation head 4, a left output rod 5, a left preload spring 6, and a left flutter seal assembly 11.

[0027] In this embodiment, the top of the actuating piston structure is a cylindrical left dither actuator head 4 with a circumferential groove. This left dither actuator head 4 is connected to the inner wall of the left cavity of the hydraulic housing 1 in a multi-stage sealed manner via a left dither seal ring assembly 11. The center of the bottom of the left dither actuator head 4 is connected to the left output rod 5. This left output rod 5 is an inverted T-shaped trapezoidal metal connecting rod. The upper portion is a small-diameter metal round rod with a threaded top screw that is screwed into the bottom center threaded hole of the left dither actuator head 4. The bottom portion is a large-diameter rod cap that extends into the left cavity of the actuating housing 2. The middle rod body of the left output rod 5 is sheathed with a left preload spring 6. The bottom of the left preload spring 6 is pressed and fixed to the upper surface of the rod cap of the left output rod 5. The top of the left preload spring 6 is fixed to the shoulder in the left motion cavity of the actuating housing 2. The specific fixing position is described in detail below.

[0028] The two independent motion chambers inside the actuating housing 2 are designed with a left-right symmetrical structure. Taking the left motion chamber as an example, the left motion chamber is a through hole that runs through the actuating housing 2. It can be divided into three cylindrical cavities of different diameters in the longitudinal direction. After installation, the overall position is coaxially arranged longitudinally with the left pressure excitation chamber in the oil pressure housing 1. Among them, the diameter of the cylindrical cavity in the upper part of the left motion chamber is smaller than the minimum diameter of the cavity in the oil pressure housing 1, the diameter of the cylindrical cavity in the middle part is slightly larger than the maximum diameter of the cavity in the oil pressure housing 1, and the diameter of the cylindrical cavity in the lower part is the largest. The interior of the upper part of the cavity of the left motion chamber is the middle part of the left output rod 5, which is used to realize the rigid motion connection between the bottom rod cap of the left output rod 5 and the top left vibration excitation head 4; the interior of the middle part of the cavity of the left motion chamber is the bottom rod cap part of the left output rod 5, which is used to realize the motion guide space of the left output rod 5. The shoulder transition surface between the upper and middle portions of the left motion chamber serves as the compression and securing location for the top of the left preload spring 6, enabling downward rebound preload of the left output rod 5. The lower cavity of the left motion chamber houses the electromagnetic excitation structure of the left electromagnetic excitation actuator, which includes a left permanent magnet assembly 7, a left excitation coil 8, a left Terfenol-D rod 9, and a left strain gauge assembly 10.

[0029] In this embodiment, the electromagnetic excitation structure is an annular multi-layer cylindrical structure. From the inside out, it comprises the innermost left Terfenol-D rod 9, the left strain gauge assembly 10, the left excitation coil 8, and the left permanent magnet assembly 7. The left strain gauge assembly 10 is glued to the outer surface of the left Terfenol-D rod 9, while the left excitation coil 8 and the left permanent magnet assembly 7 are fixed to the inner wall of the lower cavity of the left motion chamber. The excitation external circuit wire of the left excitation coil 8 is led out through an external through-hole on the left side of the inner wall of the lower cavity of the left motion chamber. After installation, the external through-hole is glued and sealed.

[0030] The right electromagnetic actuator utilizes the same structure, including a right cone-valve exhaust valve 12, a right dither actuator head 13, a right output rod 14, a right preload spring 15, a right permanent magnet assembly 16, a right excitation coil 17, a right Terfenol-D rod 18, a right strain gauge assembly 19, and a right dither seal ring assembly 20. These components are connected and mounted symmetrically to the left electromagnetic actuator, forming a controllable, retractable hydraulic piston with upper and lower seals, and their detailed description is omitted here.

[0031] The application of this embodiment, such as Figure 2As shown, the flutter excitation device is sealedly connected to the oil chambers on both sides of the hydraulic cylinder piston. Adjustment of the exhaust valve keeps the connecting oil circuits filled with hydraulic oil. Furthermore, when different control waveform signals are input to the left and right parts of the flutter excitation device, an external NF power supply sends real-time signal instructions, which in turn input corresponding current signals to the excitation coils 8 and 17 of the Terfenol-D rods. This, in conjunction with the permanent magnet groups 7 and 16 and preload springs 6 and 15, causes the Terfenol-D rods 9 and 18 to perform high-frequency extension and contraction motions with the desired waveform. The motion state of the Terfenol-D rods is monitored and fed back in real time by the left and right strain gauge groups 10 and 19, achieving higher-precision flutter motion control. The preload springs 6, 15 and the support end caps 23 transfer the axial deformation rigidity of the Terfenol-D rods 9, 18 to the output rods 5, 14, further driving the vibration excitation heads 4, 13 to move precisely with the desired waveform, and ultimately acting on the high-pressure oil. The vibration excitation pressure wave is transmitted to the surface of the hydraulic cylinder piston through the oil circuit, providing a differential high-frequency vibration force.

[0032] Working Principle: Terfenol-D generates high-frequency telescopic motion under the influence of an excitation magnetic field. This high-frequency telescopic motion is transmitted via the output rod to the dither head, which comes into direct contact with high-pressure oil, generating a two-phase dither oil pressure. The high-pressure oil dither head is connected to the excitation chamber via a piston, ensuring rigid transmission of the excitation load. The differential high-frequency dither force on both sides of the piston causes the hydraulic cylinder piston to vibrate at a high frequency, triggering a dither friction-reducing effect, resulting in low-friction characteristics for the hydraulic cylinder.

[0033] The so-called high-frequency vibration friction reduction refers to the introduction of high-frequency excitation (0-2000 / 10000Hz) on one or more sides of the friction pair, so that the friction pairs are in a high-frequency relative motion state, thereby keeping the friction force in the dynamic friction state to reduce the dead zone effect caused by the maximum static friction.

[0034] The excitation coils 8 and 17 can be connected to the driving power supply device in the following manner: one end of the two soft wires is welded to the excitation coil input connector, and then the other end of the soft wire passes through the wire embedding groove left by the support end cover 23 and the actuating shell 2 and is connected to the driving power supply device, and then the groove part is sealed by a rubber gasket.

[0035] Parameter Design Method: The flutter wave amplitude is directly related to factors such as the volume of the oil in the two chambers of the hydraulic cylinder, the elastic modulus, and pipeline deformation. For a given system, the corresponding mathematical relationship can be easily derived to determine the required volume change of the hydraulic oil. Therefore, in actual implementation, the flutter wave amplitude and frequency information can be used to complete the design of the flutter power and flutter head.

[0036] The above-described embodiments merely express the implementation methods of the present invention, but should not be understood as limiting the scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A broadband high-frequency flutter differential pressure wave excitation device, characterized in that: The broadband high-frequency vibration differential pressure wave excitation device is a bilaterally symmetrical structure, comprising an upper oil pressure housing (1), a lower actuating housing (2), a support end cover (23) at the bottom of the actuating housing (2), two pressure chambers located inside the oil pressure housing (1), the actuating housing (2), and the support end cover (23), and an electromagnetic excitation actuator installed in the pressure chamber, respectively providing differential hydraulic excitation waves for the two chambers of the hydraulic cylinder; The oil pressure housing (1) is sealed to the top of the actuating housing (2), and the bottom of the actuating housing (2) is sealed to the support end cover (23); the two pressure chamber parts are respectively composed of the left and right cavities inside the oil pressure housing (1) and the actuating housing (2), including a left pressure chamber and a right pressure chamber; the left electromagnetic excitation actuator is installed in the left pressure chamber, and the right electromagnetic excitation actuator is installed in the right pressure chamber; the oil pressure housing (1) is provided with two symmetrically arranged left and right pressure excitation chambers, and the actuating housing (2) is provided with two symmetrically arranged left and right motion chambers; the left pressure chamber is composed of a left pressure excitation chamber and a left motion chamber, and the right pressure chamber is composed of a right pressure excitation chamber and a right motion chamber; The oil pressure housing (1) is a symmetrical double-cavity structure, and the left pressure excitation chamber is used for illustration: the left pressure excitation chamber is a trapezoidal cylindrical through hole that passes through the oil pressure housing (1), and can be divided into two cylindrical cavities of different diameters in the longitudinal direction, and the diameter of the upper cylindrical cavity is smaller than the diameter of the lower cylindrical cavity; the upper cylindrical cavity is connected to the output interface end of the oil, and the lower cylindrical cavity has an exhaust hole reserved in the shoulder part connected to the upper small-diameter cylindrical cavity, and the exhaust hole is fixedly connected to the left cone valve type exhaust valve (3) to realize the exhaust function; the actuating piston structure of the left electromagnetic excitation actuator is installed in the lower cylindrical cavity; the actuating piston structure includes a left vibration excitation head (4), a left output rod (5), and a left preload spring (6); the two independent motion chambers inside the actuating housing (2) are left-right symmetrical structures; the left motion chamber is used for illustration: the left motion chamber is a through hole that passes through the actuating housing The through hole of (2) is longitudinally divided into three cylindrical cavities with successively larger diameters, including an upper cylindrical cavity, an intermediate cylindrical cavity, and a lower cylindrical cavity, which are longitudinally arranged coaxially with the left pressure excitation chamber in the oil pressure housing (1) after installation; the interior of the upper cylindrical cavity is the middle part of the left output rod (5), and the interior of the intermediate cylindrical cavity is the bottom rod cap structure of the left output rod (5), which serves as a motion guide space for the left output rod (5); the convex shoulder transition surface between the upper cylindrical cavity and the intermediate cylindrical cavity is the compression and fixing position of the top of the left preload spring (6), which realizes the downward movement and rebound of the left output rod (5); the interior of the lower cylindrical cavity is equipped with an electromagnetic excitation structure of the left electromagnetic excitation actuator, and the electromagnetic excitation structure includes a left permanent magnet group (7), a left excitation coil (8), a left Terfenol-D rod (9), and a left strain gauge group (10).

2. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The top of the actuating piston structure in the oil pressure housing (1) is a cylindrical left vibration excitation head (4) with a circumferential groove; the center position of the bottom of the left vibration excitation head (4) is connected to the left output rod (5); the left output rod (5) is a trapezoidal metal connecting rod with an inverted T-shaped structure, the upper part is a metal round rod, and the bottom is a rod cap structure, and the rod cap extends to the left cavity of the actuating housing (2); the middle rod body part of the left output rod (5) is covered with a left pre-load spring (6), and the top of the left pre-load spring (6) is fixed to the boss in the left movement cavity inside the actuating housing (2); The electromagnetic excitation structure of the left electromagnetic excitation actuator in the actuation housing (2) is an annular multi-layer cylindrical structure, which comprises, from the inside to the outside, the innermost left Terfenol-D rod (9), the left strain gauge group (10), the left excitation coil (8) and the left permanent magnet group (7); the left strain gauge group (10) is adhered to the outer surface of the left Terfenol-D rod (9), the left excitation coil (8) and the left permanent magnet group (7) are fixed to the inner wall surface of the cylindrical cavity below; the excitation external circuit wire of the left excitation coil (8) is led out from the through hole of the cylindrical cavity wall; The right electromagnetic excitation actuator and the left electromagnetic excitation actuator in the actuation housing (2) have the same structure.

3. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The diameter of the upper cylindrical cavity of the left motion chamber in the actuating housing (2) is smaller than the minimum diameter of the cavity of the oil pressure housing (1), the diameter of the middle cylindrical cavity is larger than the maximum diameter of the cavity in the oil pressure housing (1), and the diameter of the lower cylindrical cavity is the largest.

4. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The left vibration excitation head (4) of the actuating piston structure is connected to the inner wall of the left cavity of the oil pressure housing (1) in a multi-stage sealing manner via a left vibration sealing ring group 11.

5. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The top portion of the upper cylindrical cavity of the oil pressure housing (1) is designed with a protruding integrated annular interface, the outside of which is a standard thread for sealing and mounting with an external oil pipeline.

6. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The lower end surface of the oil pressure housing (1) is sealed and fixedly connected to the upper end surface of the actuating housing (2) through a housing sealing gasket (22) under the pressure of a housing fixing screw group (21).

7. The broadband high-frequency flutter differential pressure wave excitation device according to claim 1, characterized in that: The lower end surface of the actuating housing (2) is sealed and fixedly connected to the upper end surface of the supporting end cover (23) through the end cover sealing gasket (25) under the pressure of the end cover fixing screw group (24).

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