Active coherent plunger pump oil pulsation suppression device and method

Abstract

The invention provides an active coherent plunger pump oil pulsation suppression device and method, the active coherent plunger pump oil pulsation suppression device comprises two piezoelectric patches and an adjusting unit, the piezoelectric patches are provided with axial through holes, and the adjusting unit is electrically connected with the piezoelectric patches. When oil enters the inner cavity, the outer side piezoelectric plate deforms due to pulsation excitation and generates a first charge signal, the adjusting unit processes the first charge signal in real time and then outputs a reverse driving signal to the inner side piezoelectric plate, and the inverse piezoelectric effect is triggered to generate reverse fluctuation suppression pulsation with the same amplitude and opposite phases; and when the oil flows out, the inner side piezoelectric plate generates a second charge signal, and the adjusting unit processes the second charge signal and then drives the outer side piezoelectric plate to generate reverse fluctuation. The device realizes bidirectional pulsation suppression through the forward / inverse piezoelectric effect of the double piezoelectric patches. The plunger pump can generate anti-phase vibration waves in a self-adaptive mode, is compact in structure and rapid in response, does not need an external power source, and remarkably improves the operation stability and the service life of the plunger pump.

Description

Technical Field

[0001] This invention relates to the field of plunger pumps, and in particular to an active coherent plunger pump oil pulsation suppression device and method. Background Technology

[0002] Hydraulic systems are widely used in fields such as engineering machinery and aerospace, with axial piston pumps being one of the most commonly used hydraulic power components. However, due to the reciprocating motion characteristics of piston pumps during operation, the output oil pressure and flow rate will fluctuate periodically, forming oil pulsation. This pulsation not only causes system vibration and noise but also reduces the system's working accuracy, shortens equipment lifespan, and seriously affects the overall performance of the hydraulic system.

[0003] Currently, the main methods for suppressing oil pulsation fall into two categories: passive and active. Passive suppression devices mainly consist of structures such as expansion chambers and accumulators. Although simple to implement, their resonant frequency is fixed, making it difficult to adapt to changes in pulsation frequency under different operating conditions, resulting in a significant decrease in the high-frequency vibration suppression effect. Active suppression devices, while capable of dynamic adjustment, generally suffer from slow response speed, complex structure, and high cost. For example, while electro-hydraulic servo valve control can dynamically adjust flow, it requires an external hydraulic circuit and independent power supply, making the system complex and expensive. Single piezoelectric control schemes, such as feedback control with piezoelectric ceramics installed at the end of the pipeline, suffer from phase lag due to the limitation of the sensor and actuator being in the same position, resulting in low actual vibration suppression efficiency.

[0004] Furthermore, existing technologies generally struggle to cover the full frequency range of piston pump pulsation, and active control devices rely on external energy sources, which does not align with the trend towards compact and integrated hydraulic systems. With increasing demands for quietness and reliability in industrial applications, there is an urgent need to develop an oil pulsation suppression device that can achieve wide-band dynamic adaptive adjustment, has a compact structure, fast response speed, and requires no external energy source. Summary of the Invention

[0005] The main objective of this invention is to overcome the shortcomings of existing oil pulsation suppression technologies, such as slow response speed, complex structure, and high cost, and to propose an active coherent plunger pump oil pulsation suppression device and method, which features a compact structure, rapid response, and low cost.

[0006] The present invention adopts the following technical solution:

[0007] An active coherent plunger pump oil pulsation suppression device is characterized by comprising two piezoelectric plates and an adjustment unit; the two piezoelectric plates are axially spaced and installed in the inner cavity of the plunger, and the piezoelectric plates are provided with a plurality of axially penetrating through holes; the adjustment unit is electrically connected to the two piezoelectric plates.

[0008] When the oil enters the plunger cavity, the piezoelectric plate near the outer side deforms under the excitation of oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The adjustment unit collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the inner side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0009] When the oil flows out of the plunger's inner cavity, the piezoelectric plate near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The adjustment unit collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the outer side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0010] The two piezoelectric elements have opposite polarization directions, and their opposite surfaces are polarized back surfaces and connected to the adjustment unit to achieve signal input and output. The opposite surfaces of the two piezoelectric elements are polarized back surfaces to achieve wave energy reception and release.

[0011] The piezoelectric element is radially arranged in the inner cavity, and the outer periphery of the piezoelectric element is detachably fixed to the inner wall of the inner cavity.

[0012] The piezoelectric sheet has several elastic steel claws on its outer periphery, and several circumferentially distributed slots on the inner wall of the cavity. The elastic steel claws are inserted into the corresponding slots to achieve a detachable and fixed connection.

[0013] The through holes are evenly distributed on the piezoelectric sheet, and the through holes are circular, rectangular or prismatic.

[0014] An installation groove is also provided inside the inner wall between the two piezoelectric pieces in the inner cavity, and the adjustment unit is installed in the installation groove.

[0015] The adjustment unit includes a charge amplification module, a signal processing module, and a high-voltage drive module. The charge amplification module amplifies the charge signal generated by the piezoelectric element and converts it into a voltage signal. The signal processing module calculates the pulsation amplitude and phase in real time. The high-voltage drive module generates a reverse drive signal with the same amplitude and opposite phase according to the pulsation amplitude and phase and outputs it to the piezoelectric element.

[0016] The regulating unit is also equipped with an energy storage capacitor, which reuses the electrical energy generated by the piezoelectric element to achieve closed-loop self-powered operation.

[0017] A method for suppressing oil pulsation in an active coherent plunger pump involves pre-installing two piezoelectric plates axially spaced apart inside the plunger cavity, with several axially penetrating through holes on the piezoelectric plates; and setting an adjustment unit electrically connected to the two piezoelectric plates.

[0018] When the oil enters the plunger cavity, the piezoelectric plate near the outer side deforms under the excitation of oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The adjustment unit collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the inner side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0019] When the oil flows out of the plunger's inner cavity, the piezoelectric plate near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The adjustment unit collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the outer side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0020] By adjusting the driving voltage V of the piezoelectric element drive The coherent wave amplitude is controlled by adjusting the driving current I of the piezoelectric element. drive The phase of the coherent wave is controlled as follows:

[0021]

[0022] I drive (jω)=jωC0V drive (jω);

[0023] Where η is a safety factor set based on the thermal failure threshold of the piezoelectric element, and P max Where S is the rated power of the piezoelectric element, S is the effective working area of ​​the piezoelectric element, c is the speed of sound, ρ is the density of the oil, and F is the rated power of the piezoelectric element. pzt C0 is the piezoelectric output force; C0 is the piezoelectric electrostatic capacitance, ω=2πf, f is the real-time detected oil pulsation frequency.

[0024] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0025] In this invention, the synergistic effect of the positive and inverse piezoelectric effects is utilized. Dual piezoelectric elements dynamically switch sensor and actuator functions according to the oil flow direction, generating in real-time a reverse ripple with the same amplitude but opposite phase as the pulsation. This coherent cancellation eliminates broadband oil pulsation energy, reducing system vibration and noise, and improving operational stability. The adjustment unit collects the pulsation signal in real-time and reverses it to drive the corresponding piezoelectric element, achieving targeted suppression of different stages (intake and discharge) in the oil flow process, adapting to complex operating conditions and improving control accuracy.

[0026] In this invention, the piezoelectric element is detachably fixed to the inner wall of the cavity. The piezoelectric element is quickly installed and removed via an embedded connection between a flexible steel claw and a slot, improving maintenance efficiency. The design of the slot and the steel claw ensures the stability of the piezoelectric element under vibration, preventing performance degradation due to loosening.

[0027] In this invention, the regulating unit is also equipped with an energy storage capacitor. The energy storage capacitor reuses the bidirectional energy conversion characteristics of the piezoelectric element to achieve closed-loop self-powered operation, thus avoiding the risk of oil contamination from external cables.

[0028] In this invention, the adjustment unit is integrated inside the inner wall of the cavity, eliminating the need for an external hydraulic circuit and an independent power supply, thus significantly reducing system complexity and manufacturing costs. Attached Figure Description

[0029] Figure 1 This is a schematic cross-sectional view of the overall structure of the device of the present invention;

[0030] Figure 2 This is a detailed diagram of the elastic steel claw structure in the device of the present invention;

[0031] Figure 3 This is a partial schematic diagram of the piezoelectric element in the device of the present invention;

[0032] Figure 4 This is a schematic diagram of a flexible steel claw mounted on a piezoelectric plate.

[0033] Figure 5 This is a partial schematic diagram of the plunger's internal cavity;

[0034] Figure 6 A schematic diagram showing the elastic steel claw being engaged in the slot;

[0035] Figure 7 Schematic diagram of fluororubber sealing plugs filling wire holes;

[0036] Figure 8 A schematic diagram of the structure of the device of the present invention, which illustrates the principle of coherent cancellation of oil pulsation waves (oil outflow plunger);

[0037] Figure 9This is a schematic diagram of the structure of the device of the present invention, which shows the principle of coherent cancellation of oil pulsation waves (oil flowing into the plunger);

[0038] Figure 10 This is a schematic diagram illustrating the working principle of the device of the present invention;

[0039] Figure 11 This is a comparison chart of the pulsation suppression effect of the device of the present invention;

[0040] in:

[0041] 1. Plunger; 2. Adjustment unit; 3. Piezoelectric element; 3a. First groove; 4. Inner cavity; 5. Elastic steel claw; 5a. Inclined surface; 5b. Locking boss; 5c. Second groove; 5d. Hollowed-out area; 6. Mounting groove; 7. Through hole; 8. Slot; 9. Wire hole; 10. Fluororubber sealing plug.

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0043] The present invention will be further described below through specific embodiments.

[0044] See Figures 1 to 6 This invention discloses an active coherent plunger pump oil pulsation suppression device, comprising two piezoelectric plates 3 and an adjusting unit 2. The two piezoelectric plates 3 are axially spaced and installed in the inner cavity 4 of the plunger 1. One piezoelectric plate 3 is located near the outer side of the inner cavity 4, i.e., the side where the oil inlet and outlet are located, while the other piezoelectric plate 3 is located near the inner side of the inner cavity 4, i.e., the side where the slipper is located. Each piezoelectric plate 3 is provided with several axially penetrating through holes 7, which are circular, rectangular, prismatic, or other shapes that allow oil to flow through. The adjusting unit 2 is electrically connected to the two piezoelectric plates 3.

[0045] When the oil enters the inner cavity 4 of the plunger 1, the piezoelectric plate 3 near the outer side deforms under the excitation of the oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The regulating unit 2 collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate 3 near the inner side, so that the piezoelectric plate 3 generates a reverse wave with the same amplitude and opposite phase as the oil pulsation under the action of the reverse piezoelectric effect to suppress the pulsation.

[0046] When the oil flows out of the inner cavity 4 of the plunger 1, the piezoelectric plate 3 near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The regulating unit 2 collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate 3 near the outer side, so that the piezoelectric plate 3 generates a reverse wave with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0047] This invention utilizes the synergistic effect of the positive and inverse piezoelectric effects. The dual piezoelectric elements 3 dynamically switch sensor and actuator functions according to the oil flow direction, generating in real-time a reverse ripple with the same amplitude but opposite phase as the pulsation. This coherent cancellation eliminates broadband oil pulsation energy, reducing system vibration and noise, and improving operational stability. The adjustment unit 2 collects the pulsation signal in real-time and drives the corresponding piezoelectric element 3 in the reverse direction, achieving targeted suppression of different stages (intake and discharge) during oil flow, adapting to complex operating conditions and improving control accuracy.

[0048] Furthermore, the two piezoelectric elements 3 have identical structures. Each piezoelectric element 3 has a polarized front side and a polarized back side. The two piezoelectric elements 3 are installed with opposite polarization directions, that is, the opposite sides of the two piezoelectric elements 3 are the polarized back sides. The polarized back sides of the two piezoelectric elements 3 are connected to the adjustment unit 2 to realize signal input and output. The opposite sides of the two piezoelectric elements 3 are polarized back sides to realize wave energy reception and release. When the piezoelectric element 3 is impacted by oil pulsation on the polarized front side, it generates an analog electrical signal based on the positive piezoelectric effect. The polarized back side is controlled by the electrical signal of the adjustment unit 2 and can generate a canceling wave that cancels the oil pulsation based on the inverse piezoelectric effect. That is, in the dual piezoelectric element 3 structure, one piezoelectric element 3 acts as a sensor, and the other piezoelectric element 3 acts as an actuator. The two dynamically switch functions according to the oil flow direction.

[0049] The piezoelectric element 3 is radially arranged in the inner cavity 4. The outer periphery of the piezoelectric element 3 is detachably fixed to the inner wall of the inner cavity 4, which is detachable, low-cost, and easy to maintain. In practical applications, the detachable fixed connection between the outer periphery of the piezoelectric element 3 and the inner wall of the inner cavity 4 can be achieved using common detachable connections, such as snap-fit ​​or interlocking. Taking snap-fit ​​as an example, several elastic steel claws 5 are provided on the outer periphery of the piezoelectric element 3, and several circumferentially distributed slots 8 are provided on the inner wall of the inner cavity 4. The detachable fixed connection is achieved by the elastic steel claws 5 embedding into the corresponding slots 8. In its natural state, the outer diameter of the elastic steel claws 5 is larger than the inner diameter of the slots 8, and the detachable fixation is achieved by the elastic steel claws 5 snapping into the slots 8. The inner wall between the two piezoelectric elements 3 in the inner cavity 4 is also provided with an installation groove 6. The installation groove 6 is not connected to the inner cavity 4, and the adjustment unit 2 is installed in the installation groove 6. The shape and size of the installation groove 6 can be set according to the shape and size of the adjustment unit 2. The wires led out from the piezoelectric piece 3 can pass through the elastic steel claw 5 and the slot 8 to the mounting slot 6 and be electrically connected to the piezoelectric piece 3. That is, the slot 8 and the elastic steel claw 5 can be provided with wire holes 9.

[0050] See Figure 2 , Figure 3For example, the plunger 1 can be made of ordinary carbon steel, and the inner cavity 4 has a cylindrical structure, for example, an inner diameter of 14.50±0.25mm and a length of 42.50mm. The piezoelectric sheet 3 is made of PZT-8 piezoelectric ceramic sheet with a diameter of φ14.50±0.25mm, a thickness of 1.0mm, a piezoelectric constant of 350×10-12C / N, and a dielectric constant of 1200. Several through holes 7 with a diameter of less than φ1mm are opened in the center as oil flow channels, and eight sets of first grooves 3a with a width of 1.2mm are evenly distributed on the edge. The first grooves 3a extend parallel to the axis of the plunger 1 and have a groove depth of 0.25mm. The elastic steel claw 5 is made of 60Si2MnA spring steel, with a width of 1.2mm and a height of 1.5mm. The inner side is provided with a second groove 5c with a height of 1.0mm to clamp the edge of the piezoelectric sheet 3, which cross-fits and interlocks with the corresponding first groove 3a on the piezoelectric sheet 3. The outer side of the steel claw is machined with a 15° assembly bevel 5a with a length of 1mm. A 0.20mm×0.85mm hollow area 5d is opened in the lower center to provide elastic deformation space and forms a locking boss 5b.

[0051] During assembly, the interlocking assembly of the elastic steel claw 5 and the piezoelectric plate 3 is guided by the inclined surface 5a and inserted into the groove 8 on the inner wall of the inner cavity 4 of the plunger 1. The elastic steel claw 5 is subjected to radial compression and generates an elastic deformation of 0.25mm until the locking boss 5b is engaged in the groove 8 with a depth of 0.15mm, forming an axial preload of 40-80N. The wires led out from the piezoelectric plate 3 pass through the φ0.8mm wire hole 9 on the elastic steel claw 5, and through the wire hole 1.1 on the wall of the plunger 1 into the mounting groove 6 and connect to the adjustment unit 2. The wire hole 9 on the elastic steel claw 5 is filled with a fluororubber sealing plug 10, the wire hole 9 on the wall of the plunger 1 is coated with an epoxy resin coating, and the mounting groove 6 is filled with Shore00-30 silicone gel to form a triple oil-proof seal.

[0052] The adjustment unit 2 includes a charge amplification module, a signal processing module, and a high-voltage drive module. The charge amplification module amplifies the charge signal generated by the piezoelectric element 3 and converts it into a voltage signal. The signal processing module calculates the pulsation amplitude and phase in real time. The high-voltage drive module generates a reverse drive signal with the same amplitude and opposite phase according to the pulsation amplitude and phase and outputs it to the piezoelectric element 3.

[0053] Furthermore, the adjustment unit 2 of the present invention is also provided with an energy storage capacitor, which reuses the electrical energy generated by the piezoelectric element 3 to achieve closed-loop self-powered operation, reducing dependence on external power sources.

[0054] In practical applications, the adjustment unit 2 is integrated onto a φ12mm×15mm alumina ceramic substrate. The charge amplification module has a gain of 60-100dB, the signal processing module can use an STM32G4 series signal processor with an ADC sampling rate of 1.2MSPS, and the high-voltage drive module uses an IRSM500-025M high-voltage drive module, outputting ±120V voltage. The entire system is connected via six M6 12.9 grade high-strength bolt flanges.

[0055] See Figure 6 A method for suppressing oil pulsation in an active coherent plunger pump, implemented using the aforementioned active coherent plunger pump oil pulsation suppression device, includes the following:

[0056] When the oil enters the inner cavity 4 of the plunger 1, the piezoelectric plate 3 near the outer side deforms under the excitation of the oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The regulating unit 2 collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate 3 near the inner side, so that the piezoelectric plate 3 generates a reverse wave with the same amplitude and opposite phase as the oil pulsation under the action of the reverse piezoelectric effect to suppress the pulsation.

[0057] When the oil flows out of the inner cavity 4 of the plunger 1, the piezoelectric plate 3 near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The regulating unit 2 collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate 3 near the outer side, so that the piezoelectric plate 3 generates a reverse wave with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

[0058] Among them, see Figure 4 When the oil flow direction is from right to left, the two piezoelectric plates 3 divide the inner cavity 4 of the plunger 1 into three functional chambers: the right chamber is the original pulsation wave generation area, where oil pulsations form unsuppressed pressure fluctuations; the middle chamber is the coherent cancellation wave action area, where the piezoelectric plate 3 generates a wave with a phase difference of 180 degrees from the original wave under the drive of the adjustment unit 2; the left chamber is the synthetic wave output area, where the original wave and the cancellation wave superimpose to form a residual pulsation with significantly attenuated amplitude. When the oil flow direction changes to from left to right, the functions of the three chambers separated by the two piezoelectric plates 3 dynamically switch: the left chamber becomes the original pulsation wave generation area, the middle chamber maintains the coherent cancellation function, and the right chamber outputs the suppressed synthetic wave. The cancellation wave generated in the middle chamber satisfies the requirement that the amplitude error of the generated excitation wave is ≤5% and the phase error is within the range of ±3°.

[0059] For suppressing oil pulsation in plunger pumps, the coherent cancellation effect depends on the amplitude matching degree and phase difference between the incident wave and the canceling wave. Its mathematical model consists of the linear superposition of the incident wave field and the canceling wave field. Since the method of this invention mainly utilizes the reverse wave generated by the dual piezoelectric elements 3 to achieve interference cancellation, only a one-dimensional wave model is needed to meet the engineering accuracy requirements.

[0060] For the axial propagation mode in the plunger 1 pipe, the sound pressure wave equation can be simplified to the following form:

[0061] P total (t)=P in (t)+P cancel (t+Δt);

[0062] Where P total It is the synthesized sound pressure level, P in It is the incident wave sound pressure amplitude, P cancel It is the amplitude of the canceling wave acoustic pressure, and Δt is the time delay.

[0063] The time-domain expression of the incident wave is:

[0064] P in (t)=A in sin(2πft);

[0065] Where f is the real-time detected oil pulsation frequency, A in This is the incident wave sound pressure amplitude. Coherent destructive propagation requires the following boundary conditions:

[0066]

[0067] Where Δφ is the phase difference between the incident wave and the canceling wave. The amplitude A of the ideal canceling wave is then obtained. cancel Must meet:

[0068] A cancel =A in ;

[0069] Substituting the above relationship into the wave energy conservation equation:

[0070]

[0071] Where E sum This represents the total energy of the synthesized wave, and T is the pulsation period. Combining this with the characteristics of the oil medium (sound velocity c, density ρ), the energy E required to cancel the wave can be obtained. cancel for:

[0072]

[0073] This energy is provided by the deformation of piezoelectric element 3. According to the piezoelectric equation, the driving voltage V drive With the piezoelectric element 3 output force F pzt satisfy:

[0074] F pzt =K pzt V drive ;

[0075] In the formula Kpzt It is the electro-mechanical conversion coefficient of the piezoelectric element, K. pzt =d 33 Y, d 33 Let Y be the piezoelectric constant and Y be Young's modulus. The sound pressure amplitude generated by the piezoelectric element 3 acting on the oil is:

[0076]

[0077] Where S is the effective working area of ​​piezoelectric element 3. Solving the above equations simultaneously yields the expression for the driving voltage:

[0078]

[0079] Phase control is achieved through the drive current I drive Achieve this. The frequency domain relationship between current and voltage is:

[0080] I drive (jω)=jωC0V drive (jω);

[0081] Where C0 is the electrostatic capacitance of piezoelectric element 3, ω = 2πf, and j is the imaginary unit. The controller compensates for the inherent phase shift φ through the current feedback circuit. circuit This ensures that the total phase difference satisfies:

[0082] Δφ=φ ctrl +φ circuit =π;

[0083] φ here ctrl =π is the inverting setting for the controller.

[0084] System energy constraint E allow Derived from the thermal failure threshold of piezoelectric element 3:

[0085] E allow =ηP max ;

[0086] Where P max =2.5W is the rated power of PZT, and η=0.6 is the safety factor set based on the thermal failure threshold of piezoelectric element 3. Substituting into the voltage amplitude formula, the safety limit can be obtained:

[0087]

[0088] In summary, the controller adjusts V drive Controlling the coherent wave amplitude, via I drive Feedback control of the coherent wave phase ultimately generates the corresponding coherent wave over a wide frequency range.

[0089] like Figure 6As shown, the outlet pressure pulsation suppression effects of the original scheme without a vibration damping device and the scheme of the present invention are compared. It is evident that without a vibration damping device, the pipeline pressure fluctuation amplitude is large, exhibiting significant pulsation peaks in both low and high frequency ranges. The method of the present invention achieves more thorough pulsation attenuation in the low-frequency region and also demonstrates excellent suppression effects in the high-frequency region. This breakthrough in high-frequency suppression capability stems from the dynamic coherent cancellation mechanism of the dual piezoelectric elements 3: real-time detection of oil pulsation waveforms generates a cancellation wave with precise phase reversal; combined with the automatic switching of the sensing-actuation function along the flow direction of the dual piezoelectric elements 3, a continuous adaptive cancellation loop is formed. This design integrates the principles of low-frequency mechanical impedance matching and high-frequency coherent wave interference, achieving stable pressure pulsation control over a wide frequency range.

[0090] In this invention, the terms "first," "second," and "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. The use of terms such as "upper," "lower," "left," "right," "front," and "rear" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention, not to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this invention. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0091] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0092] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. An active coherent plunger pump oil pulsation suppression device, characterized in that, It includes two piezoelectric elements and an adjustment unit; the two piezoelectric elements are axially spaced and installed in the inner cavity of the plunger, and the piezoelectric elements are provided with a plurality of axially penetrating through holes; the adjustment unit is electrically connected to the two piezoelectric elements. When the oil enters the plunger cavity, the piezoelectric plate near the outer side deforms under the excitation of oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The adjustment unit collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the inner side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation. When the oil flows out of the plunger's inner cavity, the piezoelectric plate near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The adjustment unit collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the outer side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

2. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, The two piezoelectric elements have opposite polarization directions, and their opposite surfaces are polarized back surfaces and connected to the adjustment unit to achieve signal input and output. Their opposite back surfaces are polarized back surfaces to achieve wave energy reception and release.

3. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, The piezoelectric element is radially arranged in the inner cavity, and the outer periphery of the piezoelectric element is detachably fixed to the inner wall of the inner cavity.

4. The active coherent plunger pump oil pulsation suppression device as described in claim 3, characterized in that, The piezoelectric sheet has several elastic steel claws on its outer periphery, and several circumferentially distributed slots on the inner wall of the cavity. The elastic steel claws are inserted into the corresponding slots to achieve a detachable and fixed connection.

5. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, The through holes are evenly distributed on the piezoelectric sheet, and the through holes are circular, rectangular or prismatic.

6. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, An installation groove is also provided inside the inner wall between the two piezoelectric pieces in the inner cavity, and the adjustment unit is installed in the installation groove.

7. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, The adjustment unit includes a charge amplification module, a signal processing module, and a high-voltage drive module. The charge amplification module amplifies the charge signal generated by the piezoelectric element and converts it into a voltage signal. The signal processing module calculates the pulsation amplitude and phase in real time. The high-voltage drive module generates a reverse drive signal with the same amplitude but opposite phase according to the pulsation amplitude and phase, and outputs it to the piezoelectric element.

8. The active coherent plunger pump oil pulsation suppression device as described in claim 1, characterized in that, The regulating unit is also equipped with an energy storage capacitor, which reuses the electrical energy generated by the piezoelectric element to achieve closed-loop self-powered operation.

9. A method for suppressing oil pulsation in an active coherent plunger pump, characterized in that, Two piezoelectric sheets are pre-installed in the inner cavity of the plunger with axial spacing, and the piezoelectric sheets are provided with several axially penetrating through holes; and the adjustment unit is electrically connected to the two piezoelectric sheets. When the oil enters the plunger cavity, the piezoelectric plate near the outer side deforms under the excitation of oil pulsation and generates a first charge signal based on the positive piezoelectric effect. The adjustment unit collects the first charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the inner side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation. When the oil flows out of the plunger's inner cavity, the piezoelectric plate near the inner side deforms under the excitation of the oil pulsation and generates a second charge signal based on the positive piezoelectric effect. The adjustment unit collects the second charge signal in real time, processes it, and outputs a reverse drive signal to the piezoelectric plate near the outer side, so that the piezoelectric plate generates a reverse ripple with the same amplitude and opposite phase as the oil pulsation under the action of the inverse piezoelectric effect to suppress the pulsation.

10. The method for suppressing oil pulsation in an active coherent plunger pump as described in claim 9, characterized in that, By adjusting the driving voltage V of the piezoelectric element drive The coherent wave amplitude is controlled by adjusting the driving current I of the piezoelectric element. drive The phase of the coherent wave is controlled as follows: I drive (jω)=jωC0V drive (jω); Where η is a safety factor set based on the thermal failure threshold of the piezoelectric element, and P max Where S is the rated power of the piezoelectric element, S is the effective working area of ​​the piezoelectric element, c is the speed of sound, π is the density of the oil, and F is the effective power of the piezoelectric element. pzt C0 is the piezoelectric output force; C0 is the piezoelectric electrostatic capacitance, ω=2πf, f is the real-time detected oil pulsation frequency.

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