A high-precision venturi valve characteristic nonlinear compression spring preparation method and compression spring

Abstract

The application discloses a high-precision Venturi valve characteristic nonlinear compression spring preparation method and a compression spring, and realizes accurate matching of compression spring performance and nonlinear flow regulation characteristics of the Venturi valve through multi-step optimization design. The method comprises the following steps: establishing a Venturi valve curve coordinate system, calculating a flow area, calculating an external force work, fitting a spring performance curve, determining a force value range, designing a spring gradual change process, heat treatment stress relief, testing and correction, ensuring that the spring performance meets the design requirements, and completing final standardization. The application provides a calculation method for force change law of a valve core of a Venturi valve and the valve core under different valve front static pressures, obtains a theoretical force curve, calculates compression and spring force compensation required by a damping structure of the valve core of the Venturi valve, and through forward development design and production, improves the independence of air volume and pressure of the Venturi valve and the air volume control precision.

Description

Technical Field

[0001] This invention belongs to the field of Venturi valve technology and discloses a method for preparing a high-precision Venturi valve nonlinear compression spring and the compression spring itself. Background Technology

[0002] A Venturi valve is a flow regulating device designed based on fluid dynamics principles, widely used in ventilation, gas transportation, and industrial fluid control. It achieves precise flow regulation by changing the flow area inside the valve body, utilizing the relationship between flow velocity and pressure. The performance of the Venturi valve directly determines the system's regulation accuracy and energy efficiency, especially in applications requiring high-precision flow control, such as cleanroom air conditioning systems and industrial burner gas supply. However, due to the nonlinear characteristics of fluid flow, Venturi valves exhibit significant complexity in practical operation, such as pressure loss, nonlinear changes in flow area, and dynamic responses under different operating conditions.

[0003] In traditional Venturi valve design, the compression spring is a key component, and its performance directly affects the valve core's motion characteristics and adjustment accuracy. However, traditional compression spring designs are mostly based on linear stiffness assumptions, which cannot meet the adjustment requirements of Venturi valves in complex nonlinear fluid environments. This design approach often leads to the following problems: First, the valve core response is lag, making it unable to accurately match rapid changes in flow rate; second, the compression spring is prone to plastic deformation under long-term high-load conditions, affecting its service life; third, it cannot optimize the design for the characteristic requirements of different operating conditions, limiting the further development of Venturi valves in high-end applications.

[0004] Currently, the pressure compensation springs used in domestic Venturi valves are mainly manufactured using reverse engineering methods. For applications requiring low pressure and high precision, the accuracy of Venturi springs manufactured using reverse engineering and surveying methods deviates significantly from the theoretical curve, resulting in poor matching with Venturi valves. Consequently, the accuracy of domestically branded Venturi valves is generally lower than that of international brands, significantly impacting their performance. Summary of the Invention

[0005] To address the above problems, this invention provides a high-precision venturi valve characteristic nonlinear compression spring and its preparation method.

[0006] The technical solution provided by this invention is as follows:

[0007] On the one hand, a method for fabricating a high-precision venturi valve characteristic nonlinear compression spring includes the following steps:

[0008] S1. Establish the coordinate system of the Venturi valve curve:

[0009] The valve body's axial direction is defined as the x-axis, and the radial direction is defined as the y-axis. The measurement data of the valve body is substituted into the coordinate system, and the data is processed and piecewise fitted into a polynomial function.

[0010] S2: Calculate and analyze the flow area based on the expression of the valve body curve:

[0011] The flow area of ​​a venturi valve is the minimum flow area from the valve core to the valve body. The flow area of ​​the valve core at different positions is calculated based on geometric relationships and the valve body curve expression.

[0012] S3. Calculate the work done by the net external force on the system:

[0013]

[0014] In the formula, In order for the external force to do work on the system, Let be the pressure of the fluid across the cross section. For cross-sectional area, unit of time Displacement of the internal fluid;

[0015] S4. Fitting the spring performance curve:

[0016] Based on the work done by the net external force on the system, the dynamic pressure at the inlet of the valve and the flow pressure of the airflow at any flow area are calculated. When the flow rate is limited to a fixed flow rate, the relationship between the spring force F (N) and the valve core position under that flow rate can be obtained, and a spring performance curve suitable for the Venturi valve can be fitted.

[0017] S5. Determine the force range:

[0018] Based on the flow range of different sizes of Venturi, the limiting pressure under the maximum flow rate is taken as the maximum load, and the force value range of the Venturi characteristic compression spring is taken based on this compensation force.

[0019] S6. Determine the gradual change process of the spring:

[0020] Based on the upper and lower limits of the force value, control points are determined in a non-uniform distribution. Based on the force value and motion trajectory of the control points, the spring's gradual change process is determined, including the pitch and outer diameter. The characteristic is that along the direction from the air outlet to the air inlet, the pitch gradually increases and the diameter gradually decreases.

[0021] S7. Heat treatment is performed to relieve stress.

[0022] S8. Testing and Correction: By designing and measuring the spring force value, the correction coefficient is continuously adjusted to complete the final design.

[0023] In some implementations, step S1, piecewise fitting to a polynomial function, includes:

[0024] A first-order polynomial is suitable for parts of relatively gentle change or linear trends.

[0025] Quadratic or cubic polynomials are suitable for regions with complex nonlinear variations.

[0026] The exponential function is chosen if the fitted curve shows obvious exponential decay or growth, or if the pressure changes significantly with the flow rate.

[0027] By segmenting the entire measurement data interval and fitting each segment with an appropriate polynomial, the fitting accuracy of each segment is ensured.

[0028] In some implementations, in step S2, according to the continuity equation, the flow rate Q is equal in the same rectification, i.e. , , , ,in The average flow velocity of the fluid across the cross section. For volume, and in unit time Since the fluid passes through the two cross-sections with equal volumes, we can obtain:

[0029]

[0030] In some implementations, the method for fitting a suitable spring performance curve for the venturi valve in step S4 is as follows:

[0031] Venturi valves of the same model use the same spring, and the spring stiffness is a constant physical quantity. The only difference at different airflow rates lies in the initial compression position of the spring. When the spring force is the same at different flow rates, it can be expressed as: ;

[0032] In the formula, Here is the equation relating the spring force to the valve core position at airflow Q1. This is the formula relating the spring force to the valve core position under airflow Q2. The initial compression position of the spring for different air volumes;

[0033] Therefore, the relationship between the spring force and the valve core position under different air volumes (Q1, Q2, Q3, ..., Qn) is obtained:

[0034]

[0035] This allows for the fitting of a spring performance curve suitable for a Venturi valve.

[0036] In some implementations, the method for determining the force range in step S5 is as follows:

[0037] The maximum working pressure of the Venturi characteristic compression spring is calculated as follows: ;

[0038] in, S represents the pressure difference across the valve cone, and S represents the cross-sectional area of ​​the valve cone. Viscous resistance at different flow rates;

[0039] According to Stokes' formula for viscous resistance, f = 6πηvr, where η is the viscosity coefficient of the fluid and r is the radius of the venturi valve cone.

[0040] Based on the force range, determine the maximum stiffness, and then select the appropriate spring material and wire diameter:

[0041]

[0042] in, The maximum load applied to the spring, Where is the shear stress, D is the average diameter of the spring coil, and d is the material diameter.

[0043] In some implementations, in step S6, based on the minimum control force, the first pitch is designed using a smooth transition with equal pitch and equal diameter. The pitch calculation method is mainly as follows:

[0044]

[0045] in, For the compression and displacement of each ring, Let Δ0 be the target stiffness of the nonlinear spring, and Δ0 be the working compression. The number of revolutions corresponding to the working compression amount. Total number of laps For the number of laps;

[0046] The method for calculating the diameter is as follows:

[0047]

[0048] in, This indicates the maximum load applied to the spring. Represents shear stress. Indicates the average diameter of the spring coil. Indicates the diameter of the material.

[0049] On the other hand, a high-precision venturi valve characteristic nonlinear compression spring includes a compression spring body, wherein the pitch of the compression spring body gradually increases and the diameter gradually decreases along the air outlet to air inlet direction of the venturi valve.

[0050] In some implementations, the maximum stiffness of the compression spring is 0.938 N / mm, and the diameter ranges from 20 to 50 mm.

[0051] In summary, the beneficial effects of the present invention are as follows:

[0052] (1) This invention provides a method for calculating the force variation law of the venturi valve and its valve core under different inlet static pressures. By obtaining the theoretical force curve, the pressure and spring force compensation required for the damping structure of the venturi valve core are calculated. Through positive development, design and manufacturing, the air volume pressure independence and air volume control accuracy of the venturi valve are improved.

[0053] (2) The final spring described in this invention is designed and manufactured using a combination of variable pitch and variable diameter, which results in a more delicate and precise elastic force performance than the traditional single variable pitch and single variable diameter methods.

[0054] (3) By fitting the performance curve of the compression spring, the stiffness of the spring is adjusted to be consistent with the curve characteristics of the valve body, which can significantly improve the response accuracy of the valve core to different flow changes, especially under complex working conditions, to ensure the accuracy of flow regulation. Attached Figure Description

[0055] Figure 1 For the Venturi valve, use a curvilinear coordinate system.

[0056] Figure 2 This is a schematic diagram of the flow area.

[0057] Figure 3 For spring compression test and correction curves;

[0058] Figure 4 This is a schematic diagram of the compression spring structure of the present invention;

[0059] Figure 5 This is a schematic diagram of a compression spring installed on a venturi valve. Detailed Implementation

[0060] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0061] This invention provides a method for fabricating a high-precision venturi valve nonlinear compression spring, the specific steps of which are as follows:

[0062] First, please refer to Figure 1 Establish a curve coordinate system for the Venturi valve, defining the valve body axial direction as the x-axis and the radial direction as the y-axis. Adjust the measured coordinate system to the one shown in the figure above, and process the measured data. To better reflect the rate of change of the curve, it can be piecewise fitted into a polynomial function.

[0063] Fitting of smooth regions: For the parts where the fluid velocity or pressure changes relatively linearly, a first-order polynomial is used for fitting.

[0064] Fitting complex nonlinear regions: For regions where fluid parameters vary significantly, quadratic or cubic polynomial fitting is used to improve fitting accuracy.

[0065] Fitting the region of exponential change: When the curve shows a clear trend of exponential growth or decay, an exponential function is used for fitting.

[0066] By segmenting the entire measurement data interval and fitting each segment with an appropriate polynomial, the fitting accuracy of each segment is ensured.

[0067] Specific fitting method:

[0068] 1. Data preprocessing: To ensure the accuracy of the fitting, the collected data needs to be processed as follows:

[0069] (1) Noise removal: Remove abnormal points or noise data in the measurement process. Smoothing filtering (such as Gaussian filtering) can be used for processing.

[0070] (2) Normalization: Normalize the data to a standard range (e.g., 0 to 1) to reduce the impact of differences in data magnitude on the fit.

[0071]

[0072] (3) Segmented analysis: Based on the trend of data change, the curve is divided into multiple regions. The basis for segmentation may include the inflection point of the curve, the curvature change, and the significant change points of flow rate and pressure difference.

[0073] 2. Based on the characteristics of the curve data, select a suitable fitting function for each segment:

[0074] Linear polynomial fitting model:

[0075] ;

[0076] Quadratic polynomial fitting model:

[0077] ;

[0078] Cubic polynomial fitting model:

[0079] ;

[0080] Exponential function fitting model:

[0081] ;

[0082] 3. Fitting calculation process:

[0083] 1. Determine the segmented region: Find the segmentation points through curvature analysis. , … ;

[0084] 2. Within each segment, calculate the fitting coefficients using the least squares method. , , ;

[0085] Error function:

[0086] Take the derivative of E and set it to 0 to solve for the coefficients. , , .

[0087] Because Venturi valves are significantly pressure-independent, they can maintain stable airflow control accuracy under different pressure environments. To ensure a constant airflow through the Venturi valve under varying pressures, the valve core automatically adjusts to a suitable position when the pressure difference changes, ensuring that the flow area is correlated with the pressure, thereby guaranteeing a constant airflow.

[0088] Therefore, the flow area can be calculated and analyzed based on the expression of the valve body curve.

[0089] Please refer to Figure 2 The flow area of ​​a venturi valve is the minimum flow area from the valve core to the valve body. The flow area of ​​the valve core at different positions can be calculated based on geometric relationships and the valve body curve expression.

[0090] According to the law of conservation of kinetic energy, the work done by the net external force on the system is:

[0091] In the formula, In order for the external force to do work on the system, Let be the pressure of the fluid across the cross section. For cross-sectional area, unit of time Displacement of the internal fluid.

[0092] According to the continuity equation, the flow rate Q is equal in the same rectification process, that is... , , , ,in The average flow velocity of the fluid across the cross section. For volume, and in unit time Since the fluid passes through the two cross-sections with equal volumes, we can obtain:

[0093] .

[0094] Furthermore, the inlet dynamic pressure and the outflow pressure of any flow area can be calculated. When limited to a fixed flow rate, the relationship between the spring force F (N) and the valve core position can be obtained at that flow rate.

[0095]

[0096] Since the same model of Venturi valve uses the same spring, the spring stiffness is a constant physical quantity. The difference lies only in the initial compression position of the spring at different airflow rates. When the spring force is the same at different flow rates, it can be expressed as: ;

[0097] In the formula, Here is the equation relating the spring force to the valve core position at airflow Q1. This is the formula relating the spring force to the valve core position under airflow Q2. The initial compression position of the spring for different air volumes;

[0098] Therefore, the relationship between the spring force and the valve core position under different air volumes (Q1, Q2, Q3, ..., Qn) is obtained:

[0099]

[0100] This allows for the fitting of a spring performance curve suitable for a Venturi valve.

[0101] Based on the flow range of different sizes of Venturi springs, the limiting pressure under the maximum flow rate is taken as the maximum load. The maximum load is the maximum compensation of its nonlinear elastic force. The force value range of the Venturi characteristic compression spring is based on this compensation force.

[0102] Typically, the maximum working pressure of a Venturi valve is 750 Pa, therefore the maximum working pressure of the Venturi characteristic spring is: ;

[0103] in, S represents the pressure difference across the valve cone, and S represents the cross-sectional area of ​​the valve cone. Viscous resistance at different flow rates;

[0104] According to Stokes' formula for viscous resistance, f = 6πηvr, where η is the viscosity coefficient of the fluid and r is the radius of the venturi valve cone.

[0105] Based on the force range, determine the maximum stiffness, and then select the appropriate spring material and wire diameter:

[0106]

[0107] in, The maximum load applied to the spring, Where is the shear stress, D is the average diameter of the spring coil, and d is the material diameter.

[0108] Then, based on the upper and lower limits of the force value, control points are determined through non-uniform distribution, starting with smaller values ​​and gradually increasing them. Based on the force value at the control points and the motion trajectory, the gradual change process of the spring is determined, starting with smaller values ​​and gradually increasing them. This mainly includes the pitch and outer diameter.

[0109] The main features include a gradually increasing pitch and a gradually decreasing diameter, thereby achieving a smoother transition and exponential nonlinear mechanical performance.

[0110] Based on the minimum control force, the first pitch is designed using a smooth transition with equal pitch and equal diameter. The pitch calculation method is mainly as follows:

[0111]

[0112] in, For the compression and displacement of each ring, Let Δ0 be the target stiffness of the nonlinear spring, and Δ0 be the working compression. The number of revolutions corresponding to the working compression amount. Total number of laps For the number of laps;

[0113] The method for calculating the diameter is as follows:

[0114]

[0115] in, This indicates the maximum load applied to the spring. Represents shear stress. Indicates the average diameter of the spring coil. This indicates the material diameter. Following this logic, the spring pitch and diameter are designed sequentially, starting with the control force and compressive displacement, in ascending order.

[0116] Step S7: Heat treatment is performed to relieve stress and ensure the elastic stability of the spring during long-term operation. Specific process parameters include:

[0117] Heat treatment temperature: 350-450℃;

[0118] Insulation time: 1-2 hours;

[0119] Cooling method: slow cooling.

[0120] Heat treatment can effectively reduce the internal stress of springs and improve their durability.

[0121] S8. Testing and Correction: By measuring the spring force value and continuously adjusting the correction coefficient, the final design is completed. Please refer to the testing and correction curves. Figure 3 .

[0122] This application also provides compression springs prepared by the above method; please refer to [reference needed]. Figure 4 , Figure 5 It includes the compression spring body, and the pitch of the compression spring body gradually increases and the diameter gradually decreases in the direction from the air outlet to the air inlet of the venturi valve.

[0123] With a maximum stiffness of 0.938 N / mm and a diameter range of 20-50 mm, the spring can ensure that it provides the required stiffness while meeting material stress limits, thereby guaranteeing the accuracy of the Venturi valve.

[0124] The flow cytometry antibody microsphere packaging structure of this application can not only effectively fix antibody microspheres and prevent their displacement, but also improve the safety and reliability of storage through diversified confinement design and monitoring methods.

[0125] In summary, this invention provides a method for calculating the force variation law of the venturi valve and its valve core under different inlet static pressures. By obtaining the theoretical force curve, the required pressure and spring force compensation of the venturi valve core damping structure are calculated. Through positive development, design and manufacturing, the air volume pressure independence and air volume control accuracy of the venturi valve are improved.

[0126] It should be noted that implementations not shown or described in the accompanying drawings or the main text of the specification are all forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the elements and methods described above are not limited to the various specific structures, shapes, or methods mentioned in the embodiments.

[0127] It should also be noted that this document may provide examples of parameters containing specific values, but these parameters need not be exactly equal to the corresponding values, but can approximate the corresponding values ​​within acceptable error tolerances or design constraints. Directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," "right," "inner," and "outer," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this application.

[0128] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for manufacturing a high-precision venturi valve nonlinear compression spring, characterized in that, Includes the following steps: S1. Establish the coordinate system of the Venturi valve curve: Define the valve body axial direction as the x-axis and the radial direction as the Y-axis. Substitute the valve body's measurement data into the coordinate system and perform data processing, fitting a polynomial function piecewise. S2: Calculate and analyze the flow area based on the expression of the valve body curve: The flow area of ​​a venturi valve is the minimum flow area from the valve core to the valve body. The flow area of ​​the valve core at different positions is calculated based on geometric relationships and the valve body curve expression. S3. Calculate the work done by the net external force on the system: ； In the formula, In order for the external force to do work on the system, Let be the pressure of the fluid across the cross section. For cross-sectional area, unit of time Displacement of the internal fluid; S4. Fitting the spring performance curve: Based on the work done by the net external force on the system, the dynamic pressure at the inlet of the valve and the flow pressure of the airflow at any flow area are calculated. When the flow rate is limited to a fixed flow rate, the relationship between the spring force F (N) and the valve core position under that flow rate can be obtained, and a spring performance curve suitable for the Venturi valve can be fitted. S5. Determine the force range: Based on the flow range of different sizes of Venturi, the limiting pressure under the maximum flow rate is taken as the maximum load, and the force value range of the Venturi characteristic compression spring is taken based on this compensation force. S6. Determine the gradual change process of the spring: Based on the upper and lower limits of the force value, control points are determined in a non-uniform distribution. Based on the force value and motion trajectory of the control points, the spring's gradual change process is determined, including the pitch and outer diameter. The characteristic is that along the direction from the air outlet to the air inlet, the pitch gradually increases and the diameter gradually decreases. S7. Heat treatment is performed to relieve stress. S8. Testing and Correction: By designing and measuring the spring force value, the correction coefficient is continuously adjusted to complete the final design.

2. The method for preparing a high-precision venturi valve characteristic nonlinear compression spring according to claim 1, characterized in that, In step S1, piecewise fitting to a polynomial function includes: A first-order polynomial is suitable for parts of relatively gentle change or linear trends. Quadratic or cubic polynomials are suitable for regions with complex nonlinear variations. The exponential function is chosen if the fitted curve shows obvious exponential decay or growth, or if the pressure changes significantly with the flow rate. By segmenting the entire measurement data interval and fitting each segment with an appropriate polynomial, the fitting accuracy of each segment is ensured.

3. The method for preparing a high-precision venturi valve characteristic nonlinear compression spring according to claim 1, characterized in that, In step S2, according to the continuity equation, the flow rate Q is equal in the same rectification process, that is... , , , ,in The average flow velocity of the fluid across the cross section. For volume, and in unit time Since the fluid passes through the two cross-sections with equal volumes, we can obtain: 。 4. The method for preparing a high-precision venturi valve nonlinear compression spring according to claim 3, characterized in that, In step S4, the method for fitting a spring performance curve suitable for the Venturi valve is as follows: Venturi valves of the same model use the same spring. Spring stiffness is a constant physical quantity. At different airflow rates, the only difference lies in the initial compression position of the spring. When the spring force is the same at different flow rates, it can be expressed as: ; In the formula, Here is the equation relating the spring force to the valve core position at airflow Q1. This is the formula relating the spring force to the valve core position under airflow Q2. The initial compression position of the spring for different air volumes; Therefore, the relationship between the spring force and the valve core position under different air volumes Q1, Q2, Q3, ..., Qn is obtained: ； This allows for the fitting of a spring performance curve suitable for a Venturi valve.

5. The method for preparing a high-precision venturi valve characteristic nonlinear compression spring according to claim 4, characterized in that, In step S5, the method for determining the force range is as follows: The maximum working pressure of the Venturi characteristic compression spring is calculated as follows: ; in, S represents the pressure difference across the valve cone, and S represents the cross-sectional area of ​​the valve cone. Viscous resistance at different flow rates; According to Stokes' formula for viscous resistance, f = 6πηvr, where η is the viscosity coefficient of the fluid and r is the radius of the venturi valve cone. Based on the force range, determine the maximum stiffness, and then select the appropriate spring material and wire diameter: ； in, The maximum load applied to the spring, Where is the shear stress, D is the average diameter of the spring coil, and d is the material diameter.

6. The method for preparing a high-precision venturi valve characteristic nonlinear compression spring according to claim 5, characterized in that, In step S6, based on the minimum control force, the first pitch is designed using a smooth transition with equal pitch and equal diameter. The pitch calculation method is mainly as follows: ； in, For the compression and displacement of each ring, Let Δ0 be the target stiffness of the nonlinear spring, and Δ0 be the working compression. The number of revolutions corresponding to the working compression amount. Total number of laps For the number of laps; The method for calculating the diameter is as follows: ； in, This indicates the maximum load applied to the spring. Represents shear stress. Indicates the average diameter of the spring coil. Indicates the diameter of the material.

7. A high-precision venturi valve characteristic nonlinear compression spring, prepared by the method for preparing a high-precision venturi valve characteristic nonlinear compression spring according to claims 1-6, comprising a compression spring body, characterized in that, The spring body has a gradually increasing pitch and a gradually decreasing diameter along the air outlet to air inlet direction of the venturi valve.

8. The high-precision venturi valve nonlinear compression spring according to claim 7, characterized in that, The maximum stiffness of the compression spring is 0.938 N / mm, and the diameter ranges from 20 to 50 mm.

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