Device and method for dynamically measuring jet force of nozzle baffle valve

Abstract

The invention discloses a device and a method for dynamically measuring the jet force of a nozzle baffle valve. The device comprises a displacement adjusting mechanism; the nozzle seat is fixed to the displacement adjusting mechanism, a nozzle is arranged on the nozzle seat, a medium conveying pipeline used for conveying gas or liquid media to the nozzle is connected to the nozzle seat, and a medium pressure sensor and a constant throttling orifice plate are arranged on the medium conveying pipeline; the force sensor is fixed on a sliding block on the displacement adjusting mechanism through a bracket and is used for adjusting the size of a gap between a simulation baffle plate of the force sensor and the nozzle; and the control system is electrically connected with the medium pressure sensor and the force sensor. According to the invention, indirect measurement limitation is broken through, mechanical coupling interference is eliminated, the static measurement error is less than or equal to + / -0.5% FS, the dynamic overshoot is reduced to 38%, and the method is suitable for dynamic performance optimization of pilot-level and other precise fluid elements of the electro-hydraulic servo valve.

Description

Technical Field

[0001] This invention relates to the field of fluid control component testing technology, and more specifically to a device and method for dynamically measuring the jet force of a nozzle-baffle valve, applicable to pilot-stage performance testing of equipment such as electro-hydraulic servo valves and pneumatic regulating valves. Background Technology

[0002] The nozzle-flap valve is a core component in a hydraulic servo control system. It consists of a baffle, a nozzle, and a fixed throttling orifice. Pressure differential control is achieved by changing the variable throttling orifice formed by altering the gap between the nozzle and the baffle. This valve features fast response (up to 2.5ms step response), high control accuracy (nozzle diameter 0.3–1mm), and a compact structure. It is primarily used as a pre-amplifier stage in multi-stage hydraulic servo systems and is widely applied in precision control scenarios such as aerospace electro-hydraulic servo systems and fuel speed control systems.

[0003] There are three major technical bottlenecks in the measurement of jet force in nozzle-baffle valves:

[0004] 1) Indirect measurement error: Existing technologies obtain jet force indirectly through pressure backpropagation or image analysis, with an error >15%, resulting in zero bias of the servo valve; 2) Insufficient dynamic response: Lever-type force gauges (such as GB / T 242310 equipment) have a response frequency <100Hz, which cannot capture millisecond-level jet fluctuations; 3) Significant mechanical interference: Contact sensors change the original gap, and air source pressure fluctuations (±2%FS) further reduce measurement accuracy.

[0005] Therefore, how to develop a high-precision dynamic measurement device and method that can directly and accurately measure the jet force of nozzle-baffle valves has become a technical problem that urgently needs to be solved in the field of fluid control component testing. Summary of the Invention

[0006] In view of this, the present invention provides a direct, dynamic, and interference-free device and method for dynamically measuring the jet force of a nozzle-baffle valve, solving the problems of indirect measurement error, lack of dynamic response, and mechanical interference.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A device for dynamically measuring the jet force of a nozzle baffle valve, comprising:

[0009] Displacement adjustment mechanism;

[0010] A nozzle holder is fixed on the displacement adjustment mechanism. A nozzle is provided on the nozzle holder. A medium delivery pipeline for supplying gas or liquid medium to the nozzle is connected to the nozzle holder. A medium pressure sensor and a constant throttling orifice plate are provided on the medium delivery pipeline.

[0011] A force sensor with a simulated baffle mounted on its end face center is fixed to a slider on the displacement adjustment mechanism by a bracket, and is used to adjust the gap between the force-bearing surface of the simulated baffle and the nozzle.

[0012] The control system is electrically connected to both the medium pressure sensor and the force sensor.

[0013] Furthermore, a ceramic heat insulation layer is provided between the force sensor and the bracket.

[0014] Furthermore, the force sensor is encased in an electromagnetic shielding cover.

[0015] The present invention provides a method for measuring the dynamic jet force of a nozzle baffle valve using a device comprising the following steps:

[0016] (a) Set the initial gap d0 between the nozzle and the baffle simulation component using the displacement adjustment mechanism;

[0017] (b) Adjust the target pressure P for medium delivery, and maintain it for T1 seconds after the pressure stabilizes;

[0018] (c) Acquire the jet force signal F(t) in real time, and calculate the steady-state force value F_avg after Kalman filtering;

[0019] (d) Establish a static jet force model to address the nonlinear relationship between jet force and gap / pressure:

[0020]

[0021] Where F is the steady-state jet force, and N is the velocity.

[0022] P represents the medium pressure, in MPa.

[0023] d represents the nozzle-baffle gap, in mm;

[0024] K and α are the medium correlation coefficients, which are dimensionless numbers;

[0025] (e) Perform dynamic tests:

[0026] Trigger a pressure step excitation, collect the force response curve F(t), and based on the transfer function...

[0027]

[0028] Where F(s) is the complex frequency domain output of the jet force, in N·s;

[0029] P(s) is the complex frequency domain input of the medium pressure, in MPa·s;

[0030] S is a complex frequency variable, with units of rad / s;

[0031] τ is the inertial time constant, in seconds;

[0032] Identify the inertia coefficient τ; activate the dynamic compensation algorithm based on the τ value.

[0033] Furthermore, the adaptive correction of the medium correlation coefficient in step (d) includes k and α: for gaseous media, k and α are corrected simultaneously.

[0034]

[0035] Where γ is the gas adiabatic coefficient, which is dimensionless;

[0036] α0 is the basic decay exponent, which is dimensionless.

[0037] K0 is the basic transfer coefficient, which is dimensionless.

[0038] For liquid media, only α needs to be corrected:

[0039] α liquid =α0+β(μ-μ0)

[0040] Where μ is the dynamic viscosity, cSt;

[0041] μ0 is the reference viscosity, cSt;

[0042] β is the viscosity correction slope, which is dimensionless;

[0043] α0 is the basic decay exponent, which is dimensionless.

[0044] Furthermore, the dynamic compensation algorithm in step (e) is as follows:

[0045]

[0046] Where Fcomp(t) is the compensated jet force, in N;

[0047] F(t) represents the original measured jet, N;

[0048] τ is the inertial time constant, in seconds;

[0049] The jet force change rate is N / s;

[0050] The overshoot after compensation is ≤5%, and the rise time is ≤2ms.

[0051] Furthermore, the formula for calculating the jet force after medium correction and dynamic compensation is as follows:

[0052]

[0053] in,

[0054] Fcomp(t): Compensated dynamic jet force, N;

[0055] kcorr: Medium-corrected energy transfer coefficient, dimensionless;

[0056] αcorr: The gap decay exponent after medium correction, dimensionless;

[0057] P(t): Time-varying medium pressure, MPa;

[0058] d: Nozzle-baffle fixing gap, mm;

[0059] τ: Inertial time constant, s. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0061] Figure 1 This is a schematic diagram of the structure of a nozzle baffle valve jet force dynamic measurement device provided by the present invention.

[0062] Figure 2 This is a schematic diagram of the gap between the force sensor's force-receiving surface and the nozzle.

[0063] Figure 3 This is a schematic diagram showing the interaction between the force sensor and the simulated baffle.

[0064] Figure 4 A schematic diagram showing the installation of a nozzle on a nozzle holder.

[0065] Figure 5 This is a schematic diagram of the nozzle.

[0066] Figure 6 This is a schematic diagram simulating a baffle component. Detailed Implementation

[0067] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0068] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0070] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0071] This invention overcomes the limitations of indirect measurement, eliminates mechanical coupling interference, achieves static measurement error ≤ ±0.5%FS, and reduces dynamic overshoot to 38%, making it suitable for dynamic performance optimization of precision fluid components such as pilot stages of electro-hydraulic servo valves.

[0072] Specifically, embodiments of the present invention disclose a dynamic jet force measuring device for a nozzle-baffle valve, comprising:

[0073] The displacement adjustment mechanism 1 uses a linear guide rail (repeat positioning accuracy ±0.01mm), a slider driven by a servo motor, and a grating ruler (resolution 0.001mm) to achieve continuous adjustment of the 0.02-1mm gap 9 between the nozzle and the force sensor.

[0074] Nozzle seat 2, made of granite or cast iron, with a flatness ≤0.02mm / m, is fixed on displacement adjustment mechanism 1. Nozzle seat 2 is equipped with nozzle 3 with an orifice diameter of Φ0.5-1mm. The surface roughness of the internal flow channel of nozzle 3 is Ra≤0.8μm. A medium delivery pipeline 4 for supplying gas or liquid medium to nozzle 3 is connected to nozzle seat 2. The medium delivery pipeline 4 is equipped with a medium pressure sensor and a constant flow orifice plate 5 (orifice diameter Φ0.2-0.5mm, internal flow channel surface roughness Ra≤0.8μm). The constant flow orifice plate 5 can stabilize the fluid pressure and avoid the medium fluctuation affecting the test results.

[0075] The non-contact force sensor 6 is a piezoelectric miniature force sensor with a range of 0-5N, a resolution of 0.001N, and a natural frequency of ≥10kHz. A simulated baffle 6a is installed on the end face of the force sensor 6. The force sensor 6 is fixed on the slider 8 on the displacement adjustment mechanism 1 by the bracket 7. The slider 8 is used to adjust the size of the gap 9 between the simulated baffle 6a and the nozzle 3. The perpendicularity error between the simulated baffle and the nozzle jet direction is ≤±0.5°.

[0076] The control system 10 is electrically connected to the medium pressure sensor and the force sensor 6.

[0077] Among them, the control system 10 is based on an FPGA architecture and integrates:

[0078] Data acquisition module, sampling rate ≥100kHz;

[0079] Kalman filter algorithm unit, used for sensor signal noise reduction;

[0080] The dynamic compensation module corrects the force signal in real time based on the inertia coefficient τ.

[0081] The control system 10 includes a working condition simulation unit, which is configured as follows:

[0082] Generate stepped pressure signals: Adjust the pressure according to the preset curve within 1-60 minutes;

[0083] Execute step pressure excitation: pressure change rate ≥ 1 MPa / ms;

[0084] Synchronously acquire dynamic response data of force, gap, and pressure parameters.

[0085] In addition, the medium delivery pipeline 4 is equipped with a gas medium (dry air or nitrogen source, operating temperature -20℃-80℃) passage and a liquid medium passage, which enables the device to support gas / liquid dual medium testing.

[0086] The gas medium passage is connected to an air compressor, a three-stage filter (filtration accuracy ≤1μm), an accumulator, and a precision pressure regulating valve, with an output pressure range of 0.1-2MPa, fluctuation rate ≤±0.5%FS, and pressure pulsation ≤±1%. The liquid medium passage is connected to a hydraulic station with a built-in viscosity compensation unit, suitable for hydraulic oil with dynamic viscosity of 1-46cSt.

[0087] A ceramic heat insulation layer 11 is provided between the force sensor 6 and the bracket 7.

[0088] The force sensor 6 is encased in an electromagnetic shielding cover 12 to shield against external electromagnetic interference.

[0089] The present invention provides a method for measuring the dynamic jet force of a nozzle baffle valve using a device comprising the following steps:

[0090] (a) The initial gap d0 between the nozzle 3 and the simulated baffle 6a is set by the displacement adjustment mechanism 1 (d0≤0.02mm);

[0091] (b) Adjust the target pressure P of the medium to be transported (0.1MPa≤P≤2MPa), and hold it for T1 seconds after the pressure stabilizes (T1≥10s);

[0092] (c) Acquire the jet force signal F(t) in real time, and calculate the steady-state force value F_avg after Kalman filtering;

[0093] (d) Establish a static jet force model to address the nonlinear relationship between jet force and gap / pressure:

[0094]

[0095] Where F is the steady-state jet force, and N is the velocity.

[0096] P represents the medium pressure, in MPa.

[0097] d represents the nozzle-baffle gap, in mm;

[0098] K and α are the medium correlation coefficients, which are dimensionless numbers;

[0099] (e) Perform dynamic tests:

[0100] A pressure step excitation is triggered (ΔP ≥ 0.5 MPa, rise time ≤ 1 ms), and the force response curve F(t) is acquired and processed through a transfer function.

[0101]

[0102] Where F(s) is the complex frequency domain output of the jet force, in N·s;

[0103] P(s) is the complex frequency domain input of the medium pressure, in MPa·s;

[0104] S is a complex frequency variable, with units of rad / s;

[0105] τ is the inertial time constant, in seconds;

[0106] Identify the inertia coefficient τ;

[0107] Dynamic compensation algorithm based on τ value activation.

[0108] Note: This transfer function describes the first-order inertial characteristics of the system's dynamic response (the delay of the jet force on the step excitation), from which the inertial coefficient τ can be identified;

[0109] Inertial delay causes overshoot (>38%) and rise delay (>2ms) in the measured force signal, which cannot reflect the true dynamic characteristics of the jet force. Therefore, it is necessary to activate the dynamic compensation algorithm based on the τ value to avoid servo valve control failure caused by dynamic distortion.

[0110] The adaptive correction of the media correlation coefficient in step (d) includes:

[0111] For gaseous media, both k and α are corrected:

[0112]

[0113] Where γ is the gas adiabatic coefficient, which is dimensionless;

[0114] α0 is the basic decay exponent, which is dimensionless.

[0115] K0 is the basic transfer coefficient, which is dimensionless.

[0116] Corrections are made for different gas media, such as light gases and high-pressure gases;

[0117] For liquid media, only α needs to be corrected:

[0118] α liquid =α0+β(μ-μ0)

[0119] Where μ is the dynamic viscosity, cSt (centistokes);

[0120] μ0 is the reference viscosity, cSt;

[0121] β is the viscosity correction slope, which is dimensionless;

[0122] α0 is the basic decay exponent, which is dimensionless.

[0123] Adjustments are made for different liquid media, such as cryogenic hydraulic oil and high-viscosity fluids;

[0124] The dynamic compensation algorithm in step (e) is as follows:

[0125]

[0126] The compensated overshoot is ≤5% and the rise time is ≤2ms.

[0127] Finally, the formula for calculating the jet force after medium correction and dynamic compensation is as follows:

[0128] in,

[0129] Fcomp(t): Compensated dynamic jet force, N;

[0130] kcorr: Medium-corrected energy transfer coefficient, dimensionless;

[0131] αcorr: The gap decay exponent after medium correction, dimensionless;

[0132] P(t): Time-varying medium pressure, MPa;

[0133] d: Nozzle-baffle fixing gap, mm;

[0134] τ: Inertial time constant, s.

[0135] This formula incorporates dual innovations: static correction (medium parameters) and dynamic compensation (inertial delay). Applications of the above method in industrial sorting:

[0136] Set the acceptable threshold for jet force;

[0137] If the measured F_avg exceeds the tolerance or the τ value is abnormal, the sorting mechanism will be triggered to remove the defective nozzle.

[0138] Establish a nozzle ID-jet force characteristic database for servo valve pairing optimization.

[0139] 1. Static calibration of gaseous media:

[0140] Nozzle: Φ0.2mm-SUS316L, torque 5N·m;

[0141] Medium: Dry air (dew point ≤ -40℃), P = 0.5MPa ± 0.001MPa;

[0142] result:

[0143] d(mm) Jet force (mN) 0.05 475.6±2.3 0.20 204.1±1.6 0.50 59.8±0.9

[0144] 2. Dynamic response optimization:

[0145] Step excitation: 0.2MPa→1.0MPa (rise time <1ms);

[0146] Compensation effect:

[0147] index Before compensation After compensation Rise time (ms) 2.0 1.3 Overshoot (%) 14.5 3.8

[0148] 3. Liquid medium expansion:

[0149] Medium: ISO VG46 hydraulic oil (20℃);

[0150] Results: When d = 0.1 mm, the jet force is 185.2 mN and the inertia coefficient η = 1.32 mN·s / MPa.

[0151] The beneficial effects of this invention are:

[0152] 1. Direct dynamic measurement: The high-frequency force sensor (10kHz) directly captures the jet force, with an error ≤ ±0.5%FS;

[0153] 2. Zero-interference design: Non-contact installation maintains the original gap, eliminating mechanical interference;

[0154] 3. Multi-condition simulation: Covers all parameters including pressure (0.1-2MPa), clearance (0.02-1mm), and medium (gas / liquid);

[0155] 4. Intelligent compensation: Dynamic inertial compensation reduces the overshoot from 145% to 38% (Example 2);

[0156] 5. Supports gas / liquid dual-medium testing and density adaptive correction.

[0157] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0158] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for dynamically measuring the jet force of a nozzle-baffle valve, characterized in that, include: Displacement adjustment mechanism (1); Nozzle seat (2), the nozzle seat (2) is fixed on the displacement adjustment mechanism (1), the nozzle seat (2) is provided with a nozzle (3), the nozzle seat (2) is connected to a medium delivery pipeline (4) for delivering gas or liquid medium to the nozzle (3), the medium delivery pipeline (4) is provided with a medium pressure sensor and a constant throttling orifice plate (5); Force sensor (6), a simulated baffle (6a) is mounted at the center of the end face of the force sensor (6). The force sensor (6) is fixed on the slider (8) on the displacement adjustment mechanism (1) by the bracket (7) to adjust the size of the gap (9) between the force-bearing surface of the simulated baffle (6a) and the nozzle (3). The control system (10) is electrically connected to the medium pressure sensor and the force sensor (6).

2. The jet force dynamic measuring device for a nozzle-baffle valve according to claim 1, characterized in that, A ceramic heat insulation layer (11) is provided between the force sensor (6) and the bracket (7).

3. The jet force dynamic measuring device for a nozzle-baffle valve according to claim 1, characterized in that, The force sensor (6) is enclosed by an electromagnetic shield (12).

4. A method for measuring the dynamic jet force of a nozzle-baffle valve as described in any one of claims 1-3, characterized in that, Includes the following steps: (a) The initial gap d0 between the nozzle (3) and the baffle simulation component (6a) is set by the displacement adjustment mechanism (1); (b) Adjust the target pressure P for medium delivery, and maintain it for T1 seconds after the pressure stabilizes; (c) Acquire the jet force signal F(t) in real time, and calculate the steady-state force value F_avg after Kalman filtering; (d) Establish a static jet force model to address the nonlinear relationship between jet force and gap / pressure: Where F is the steady-state jet force, and N is the velocity. P represents the medium pressure, in MPa. d represents the nozzle-baffle gap, in mm; K and α are the medium correlation coefficients, which are dimensionless numbers; (e) Perform dynamic tests: Trigger a pressure step excitation, collect the force response curve F(t), and based on the transfer function... Where F(s) is the complex frequency domain output of the jet force, in N·s; P(s) is the complex frequency domain input of the medium pressure, in MPa·s; S is a complex frequency variable, with units of rad / s; τ is the inertial time constant, in seconds; Identify the inertia coefficient τ; activate the dynamic compensation algorithm based on the τ value.

5. The determination method according to claim 4, characterized in that, The adaptive correction of the medium correlation coefficient in step (d) includes k and α: for gaseous media, both k and α are corrected simultaneously. Where γ is the gas adiabatic coefficient, which is dimensionless; α0 is the basic decay exponent, which is dimensionless. K0 is the basic transfer coefficient, which is dimensionless. For liquid media, only α needs to be corrected: a liquid =α0+β(μ-μ0) Where μ is the dynamic viscosity, cSt; μ0 is the reference viscosity, cSt; β is the viscosity correction slope, which is dimensionless; α0 is the basic decay exponent, which is dimensionless.

6. The determination method according to claim 4, characterized in that, The dynamic compensation algorithm in step (e) is as follows: Where Fcomp(t) is the compensated jet force, in N; F(t) represents the original measured jet, N; τ is the inertial time constant, in seconds; The jet force change rate is N / s; The overshoot after compensation is ≤5%, and the rise time is ≤2ms.

7. The determination method according to any one of claims 4-6, characterized in that, The formula for calculating the jet force after medium correction and dynamic compensation is: in, Fcomp(t): Compensated dynamic jet force, N; kcorr: Medium-corrected energy transfer coefficient, dimensionless; αcorr: The gap decay exponent after medium correction, dimensionless; P(t): Time-varying medium pressure, MPa; d: Nozzle-baffle fixing gap, mm; τ: Inertial time constant, s.

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