Method for calculating power-on and power-off delay time performance of electromagnetic valve

Abstract

The invention relates to a method for calculating the power-on and power-off delay time performance of an electromagnetic valve, and the method comprises the following steps: obtaining the mass of a valve element of the electromagnetic valve, the spring stiffness and coil resistance data; establishing an electromagnetic valve equivalent circuit model, and listing a current equation; establishing an electromagnetic valve magnetic circuit mathematical model, and listing a magnetic field equation set; establishing an electromagnetic valve flow field mathematical model, and listing a flow field equation set; establishing a kinematic model of the electromagnetic valve, and listing a kinematic equation; using a finite element method to obtain a valve core electromagnetic force-displacement-current data table and a coil inductance-displacement-current data table; a finite element method is used for obtaining a valve element aerodynamic force-displacement data table; and obtaining the power-on and power-off delay time through data analysis processing and solving of the partial differential equation set. According to the method, prediction of the opening and closing delay response time of the electromagnetic valve is more accurate, visual adjustment in the simulation process is achieved, and the time for obtaining the response time of the electromagnetic valve and the test cost are greatly reduced while the preset precision requirement is met.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic valve performance calculation technology, specifically a method for calculating the power-on and power-off delay time performance of an electromagnetic valve. Background Technology

[0002] Solenoid valves, as a basic component of automation that uses electromagnetic force to control the on / off state or flow direction of fluids, are widely used in the automotive industry, aerospace, industrial automation and other fields due to their fast response, precise control and easy integration.

[0003] Estimating the response time of a solenoid valve is a crucial step in its optimized design. While the measured response time of a solenoid valve more accurately reflects its actual dynamic characteristics than its simulated response time, relying solely on measured results during development would be extremely time-consuming and costly. Therefore, obtaining the response time of a solenoid valve through theoretical calculations is of great significance.

[0004] In existing technologies, there are two main methods for calculating the response time of solenoid valves. One method is based on the Ansys / Maxwell platform, which simulates and analyzes the response time of solenoid valves and its influencing factors. The other method is based on joint simulation using AMESim and Ansys / Maxwell platforms, which analyzes the response time of solenoid valves and its influencing factors. Both methods obtain the response time of solenoid valves through simulation, and they do not consider the influence of changes in coil inductance during the analysis, resulting in low accuracy and efficiency in calculating the delay time. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a method for calculating the power-on and power-off delay time performance of a solenoid valve, which can quickly calculate the power-on and power-off delay time of the solenoid valve with high calculation accuracy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for calculating the power-on / off delay time performance of a solenoid valve includes the following steps:

[0008] (1) Obtain the characteristic parameters of the solenoid valve, including the solenoid valve core mass data, spring stiffness data and coil resistance data;

[0009] (2) Establish the equivalent circuit model of the solenoid valve and list the circuit equations:

[0010]

[0011] In the formula, i is the operating current of the solenoid valve; t is time; U is the operating voltage of the solenoid valve; R is the coil resistance; L is the coil inductance; x is the valve core displacement; μ0 is the permeability of free space; μr The relative permeability is given by N; the number of turns in the coil is given by A; the cross-sectional area of ​​the magnetic flux is given by l; and the length of the magnetic circuit is given by l.

[0012] (3) Based on the structure of the solenoid valve, establish a mathematical model of the solenoid valve magnetic circuit and list the set of magnetic circuit equations:

[0013]

[0014] In the formula, H is the magnetic field strength; J is the current density; E is the electric field strength; B is the magnetic flux density; D is the electric flux density; ρ i σ is the charge density; μ is the permeability; σ is the conductivity; ε is the permittivity; A is the magnetic vector potential; F m It is electromagnetic force;

[0015] (4) Establish a mathematical model of the flow field of the solenoid valve and list the flow field equations:

[0016]

[0017] F pn =-∫ S p(r)·n(r)dS (8)

[0018] In the formula, ρ is the fluid density; u is the flow velocity; p is the pressure; μ is the dynamic viscosity; v is the kinematic viscosity; τ is the viscous stress tensor; f is the volume acceleration; q is the heat conduction flux; R is the gas constant; E is the energy; p(r) is the surface pressure; n(r) is the surface normal vector; F pn For surface normal aerodynamic forces;

[0019] (5) Based on the valve core mass data, spring stiffness data, electromagnetic force, and aerodynamic force, establish the kinematic model of the solenoid valve and list the kinematic equations:

[0020]

[0021] In the formula, F m (x,i) represents the electromagnetic force when the valve core displacement is x and the operating current is i; F k (x) represents the spring force when the valve core displacement is x; F p (x) represents the aerodynamic force when the valve core displacement is x; F f For friction; F v For damping force;

[0022] (6) Based on the three-dimensional digital model of the solenoid valve and the material properties of each part, establish a finite element model, set the working current range and step size, valve core movement range and movement step size, and solve the valve core electromagnetic force-displacement-current data table and inductance-displacement-current data table.

[0023] (7) Based on the three-dimensional digital model of the solenoid valve air passage, valve core displacement, fluid material properties and inlet / outlet boundary conditions, a finite element model is established, and the valve core aerodynamic-displacement data table is obtained by solving the model.

[0024] (8) Construct the interpolation vector x through data analysis. j (j = 1, 2, 3, ..., n), i k (k=1,2,3,...n); The inductance-displacement-current data table is first interpolated, then fitted, and finally differentiated to obtain L(X,I). Interpolate the electromagnetic force-displacement-current data table and the aerodynamic force-displacement data table to obtain F. m (X,I), F p (X);

[0025] X = [x1 x2 … x n ] T i = [i1 i2 … i n ] T

[0026]

[0027] In the formula: x j ∈[x min ,x max ]; i k ∈[i min i max ];L jk The displacement is x j The current is i k Inductance value at time; F mjk The displacement is x j The current is i k Electromagnetic force at that time; and The displacement is x j The current is i k The partial derivatives of the inductance with respect to displacement and current; F Pj The displacement is x j Aerodynamic forces at that time;

[0028] (9) Using the characteristic parameters of the solenoid valve and the result data obtained in step (8) as conditions, solve the partial differential equation system composed of circuit equation (1) and kinematic equation (9) to obtain the displacement-time curves under the opening and closing conditions of the solenoid valve. Combine the displacement-time curves to obtain the respective delay response time under the opening and closing conditions of the solenoid valve.

[0029] Furthermore, in step (2), based on the BH curve law of the material, the relative permeability μ rIt is a function of the solenoid valve's operating current i, the magnetic circuit length l is a function of the valve core displacement x, and the inductance L in the current equation is a function of the valve core displacement x and the solenoid valve's operating current i.

[0030] Further, in step (3), the Maxwell equations of equation system (3) are solved to obtain the magnetic induction intensity B, and then the electromagnetic force is obtained according to formula (6).

[0031] Furthermore, in step (4), based on the continuity equation, NS equation, energy equation and state equation in the equation set (7), the pressure at each point in the fluid domain is solved by the finite element method, and then the pressure is substituted into formula (8) to solve the aerodynamic force.

[0032] Furthermore, the electromagnetic force F in the kinematic equations of step (5) m It is a function of valve core displacement x and solenoid valve operating current i; spring force F k It is a function of the valve core displacement x; aerodynamic force F p It is a function of the valve core displacement x; frictional force F f It is a constant; damping force F v It is a function of velocity.

[0033] Furthermore, in step (6), the electromagnetic force finite element calculation takes the solenoid valve digital model, coil ampere-turns, material parameters, valve core movement stroke and movement step as inputs, and outputs valve core electromagnetic force-displacement curve data.

[0034] Furthermore, in step (7), before performing the formal finite element calculation, the aerodynamic simulation needs to be pre-calculated to determine the mesh generation scheme. The completed mesh includes the boundary layer mesh and the internal mesh.

[0035] Furthermore, in step (8), the experimental data processing involves using the same interpolation matrix for L(X,I). F m Interpolate (X,I) to ensure that the array dimensions in step (7) are consistent.

[0036] Furthermore, in step (9), when solving the system of partial differential equations, it is necessary to constrain the parameter x. j ∈[x min ,x max ], i k ∈[i min i max ].

[0037] In summary, the present invention has the following advantages:

[0038] 1) The established model takes into account the changes in coil inductance with valve core displacement and working current, valve core electromagnetic force with valve core displacement and working current, and valve core aerodynamic force with valve core displacement when the solenoid valve is working. This makes the prediction of the opening and closing delay response time of the solenoid valve more accurate and realizes the visualization adjustment in the simulation process.

[0039] 2) To address the issue of low efficiency in direct simulation using finite element software due to the need to traverse different operating currents and valve core positions during valve core electromagnetic force simulation, a highly efficient simulation method combining finite element simulation calculation with data analysis and post-processing is adopted. This method significantly reduces the computation time required for electromagnetic force calculation while meeting the predetermined accuracy requirements.

[0040] 3) The method of this invention allows for modeling different solenoid valve design schemes. Simulation analysis of these models reveals the dynamic response characteristics of different solenoid valves. This effectively reduces the number of experiments and provides a reference for the optimized design of solenoid valves. Attached Figure Description

[0041] Figure 1 This is a flowchart of the present invention.

[0042] Figure 2 This is a diagram showing the response time of the solenoid valve when it is energized and de-energized in this invention.

[0043] Figure 3 This is the equivalent circuit model diagram of the solenoid valve in this invention.

[0044] Figure 4 This is a schematic diagram of the electromagnetic valve's magnetic circuit in this invention.

[0045] Figure 5 This is a kinematic model diagram of the solenoid valve in this invention.

[0046] Figure 6 This is a model diagram of the solenoid valve in this invention.

[0047] Figure 7 This is a diagram of valve core electromagnetic force, valve core displacement, and working current in this invention.

[0048] Figure 8 This is a diagram showing the electromagnetic valve coil inductance, valve core displacement, and operating current in this invention.

[0049] Figure 9(a) is a three-dimensional model of the internal fluid domain of the solenoid valve in this invention.

[0050] Figure 9(b) is a diagram of valve core aerodynamics and valve core displacement in this invention.

[0051] Figure 10(a) is a diagram of the partial derivative of the coil inductance with respect to the valve core displacement in this invention.

[0052] Figure 10(b) is a diagram of the partial derivative of the coil inductance with respect to the working current in this invention.

[0053] Figure 11 This is a diagram showing the valve core displacement and voltage-time under the energized and de-energized conditions of the solenoid valve in this invention.

[0054] Figure label:

[0055] 1 is the valve core, 2 is the magnetic guide frame, 3 is the spring, 4 is the coil, and 5 is the stationary iron. Detailed Implementation

[0056] The present invention will now be described in further detail.

[0057] like Figure 1 As shown, a method for calculating the power-on / off delay time performance of a solenoid valve includes the following steps:

[0058] (1) Obtain the characteristic parameters of the solenoid valve:

[0059] The mass data of the solenoid valve core 1 was obtained using 3D modeling software; the stiffness data of the spring 3 was measured using a spring test bench; and the resistance data of the coil 4 was measured using a coil test bench.

[0060] (2) Establish the equivalent circuit model of the solenoid valve, such as Figure 3 As shown, the current equation is listed:

[0061]

[0062] In the formula, i is the working current of the solenoid valve; U is the working voltage of the solenoid valve; R is the coil resistance; L is the coil inductance, which is a function of the working current and the valve core displacement, and its value is obtained through step (6); x is the valve core displacement.

[0063] (3) Establish the electromagnetic valve magnetic circuit model as follows: Figure 4 As shown, the electromagnetic force is solved based on the finite element method:

[0064]

[0065] List Maxwell's equations for electromagnetic fields, find the constitutive relations between the four field variables: magnetic field strength H, electric field strength E, magnetic induction B, and electric flux density D, introduce the vector magnetic potential A, and let... This separates the related variables of the electric and magnetic fields. The magnetopotential potential A is obtained by solving the finite element method, and thus the magnetic induction intensity B is obtained. Combined with the electromagnetic force calculation formula (2), the magnitude of the electromagnetic force on the moving iron can be calculated.

[0066] (4) Establish a mathematical model of the flow field of the solenoid valve and solve the aerodynamic forces based on the finite element method:

[0067] Fpn =-∫ S p(r)·n(r)dS (3)

[0068] Treating the fluid as an ideal gas, it undergoes compressible flow within the solenoid valve, satisfying the ideal gas law, continuity equation, and Navier-Stokes equations. Considering temperature changes in the gas, an energy equation is introduced. The gas properties and boundary conditions at the inlet and outlet of the flow field are defined, and the pressure distribution at each point within the flow field is calculated using the finite element method.

[0069] By combining the aerodynamic force calculation formula, the magnitude of the aerodynamic force on the moving iron can be calculated.

[0070] (5) Establish the kinematic model of the solenoid valve, such as Figure 5 As shown, the kinematic equations are listed:

[0071]

[0072] In the formula, F m (x,i) is the electromagnetic force when the valve core displacement is x and the operating current is i, and its value is obtained by solving the problem using the finite element method in step (6); F k (x) is the spring force when the valve core displacement is x; F p (x) is the aerodynamic force when the valve core displacement is x, and its value is obtained by solving the finite element method in step (7); F f It is frictional force, taken as 0.01 N; F v It is the damping force, a function of the valve core velocity.

[0073] (6) Solving for the electromagnetic force of the solenoid valve:

[0074] Solenoid valve model as Figure 6 As shown. The analog-to-digital converter of the solenoid valve, the excitation current amplitude, and the number of coil turns are used as inputs. The materials of valve core 1, magnetic guide frame 2, and stationary iron 5 are defined as DT4, and the material of coil 4 is copper. The materials of the positioning ring and other structural components have similar permeability and are uniformly considered as the air domain in the simulation model. The valve core motion range is defined as 0–0.45 mm, and the motion step size is 0.05 mm. A current excitation of 0–9 A with a variation step size of 0.5 A is applied. The valve core electromagnetic force-displacement-current data table and the coil inductance-displacement-current data table are solved. The specific relationships are as follows: Figure 7 and Figure 8 As shown.

[0075] (7) Electromagnetic valve aerodynamic simulation:

[0076] Fluid domain extraction was performed based on the 3D model of the solenoid valve, resulting in a 3D model of the internal fluid domain as shown in Figure 9(a). Preliminary finite element analysis (FEM) was used to obtain the gas velocity within the air passage and determine the gas flow state. During the formal calculation, the gas domain was meshed based on the preliminary calculation results, resulting in a boundary layer mesh and an internal mesh. The mesh model, fluid material properties, and inlet / outlet pressures were used as inputs. By varying the air gap length, the aerodynamic-displacement data table of the valve core was obtained through simulation, as shown in Figure 9(b).

[0077] (8) Simulation and experimental data processing:

[0078] Simulation and Experimental Data Processing: Constructing the Interpolation Vector x j (j = 1, 2, 3, ..., n), i k (k=1,2,3,...n). The inductance-displacement-current data obtained in step (6) is first interpolated, then fitted, and finally differentiated to obtain L(X,I). in As shown in Figures 10(a) and 10(b), the electromagnetic force-displacement-current and aerodynamic force-displacement data tables obtained in steps (6) and (7) are interpolated to obtain F. m (X,I), F p (X).

[0079] X = [x1 x2 ... x] n ] T i = [i1 i2 ... i n ] T .

[0080] (9) Solve the system of partial differential equations:

[0081] Figure 2 In the diagram, t1 is the power-on delay time, t2 is the power-on motion time, and t... on t1 is the power-on response time, t2 is the power-off delay time, t3 is the power-off motion time, and t4 is the power-off movement time. off The response time is the power-down time. When solving for the response time, the original parameters of the solenoid valve and the results obtained in step (8) are used as inputs. The initial velocity, initial current, and initial valve core displacement are set to 0, and the solution time is 0.12s. Partial differential equations (1) and (4) are solved. The displacement-time curves under the opening and closing conditions of the solenoid valve are obtained, as shown below. Figure 11 As shown, the delay response time of the solenoid valve under the opening and closing conditions is obtained by combining the displacement-time curve.

[0082] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for calculating the energizing and de-energizing delay time performance of a solenoid valve, characterized in that: Includes the following steps, (1) Obtain the characteristic parameters of the solenoid valve, including the solenoid valve core mass data, spring stiffness data and coil resistance data; (2) Establish the equivalent circuit model of the solenoid valve and list the current equations: In the formula, i is the operating current of the solenoid valve; t is time; U is the operating voltage of the solenoid valve; R is the coil resistance; L is the coil inductance; x is the valve core displacement; μ0 is the vacuum permeability; μ r The relative permeability is given by N; the number of turns in the coil is given by A; the cross-sectional area of ​​the magnetic flux is given by l; and the length of the magnetic circuit is given by l. (3) Based on the structure of the solenoid valve, establish a mathematical model of the solenoid valve magnetic circuit and list the set of magnetic circuit equations: In the formula, H is the magnetic field strength; J is the current density; E is the electric field strength; B is the magnetic flux density; D is the electric flux density; ρ i σ is the charge density; μ is the permeability; σ is the conductivity; ε is the permittivity; A is the magnetic vector potential; F m It is electromagnetic force; (4) Establish a mathematical model of the flow field of the solenoid valve and list the flow field equations: F pn =-∫ S p(r)·n(r)dS (8) In the formula, ρ is the fluid density; u is the flow velocity; p is the pressure; μ is the dynamic viscosity; v is the kinematic viscosity; τ is the viscous stress tensor; f is the volume acceleration; q is the heat conduction flux; R is the gas constant; E is the energy; p(r) is the surface pressure; n(r) is the surface normal vector; F pn For surface normal aerodynamic forces; (5) Based on the valve core mass data, spring stiffness data, electromagnetic force, and aerodynamic force, establish the kinematic model of the solenoid valve and list the kinematic equations: In the formula, F m (x,i) represents the electromagnetic force when the valve core displacement is x and the operating current is i; F k (x) represents the spring force when the valve core displacement is x; F p (x) represents the aerodynamic force when the valve core displacement is x; F f For friction; F v For damping force; (6) Based on the three-dimensional digital model of the solenoid valve and the material properties of each part, establish a finite element model, set the working current range and step size, valve core movement range and movement step size, and solve the valve core electromagnetic force-displacement-current data table and inductance-displacement-current data table. (7) Based on the three-dimensional digital model of the solenoid valve air passage, valve core displacement, fluid material properties and inlet / outlet boundary conditions, a finite element model is established, and the valve core aerodynamic-displacement data table is obtained by solving the model. (8) Construct the interpolation vector x through data analysis. j (j = 1, 2, 3, ..., n), i k (k=1,2,3,...n); The inductance-displacement-current data table is first interpolated, then fitted, and finally differentiated to obtain L(X,I). Interpolate the electromagnetic force-displacement-current data table and the aerodynamic force-displacement data table to obtain F. m (X,I), F p (X); X=[x1 x2 … x n ] T ;i=[i1 i2 … i n ] T In the formula: x j ∈[x min ,x max ]; i k ∈[i min i max ];L jk The displacement is x j The current is i k Inductance value at time; F mjk The displacement is x j The current is i k Electromagnetic force at that time; and The displacement is x j The current is i k The partial derivatives of the inductance with respect to displacement and current; F Pj The displacement is x j Aerodynamic forces at that time; (9) Using the characteristic parameters of the solenoid valve and the result data obtained in step (8) as conditions, solve the partial differential equation system composed of circuit equation (1) and kinematic equation (9) to obtain the displacement-time curves under the opening and closing conditions of the solenoid valve. Combine the displacement-time curves to obtain the respective delay response time under the opening and closing conditions of the solenoid valve.

2. The calculation method according to claim 1, characterized in that: In step (2), based on the BH curve of the material, the relative permeability μ r It is a function of the solenoid valve's operating current i, the magnetic circuit length l is a function of the valve core displacement x, and the inductance L in the current equation is a function of the valve core displacement x and the solenoid valve's operating current i.

3. The calculation method according to claim 1, characterized in that: In step (3), the Maxwell equations of equation system (3) are solved to obtain the magnetic induction intensity B, and then the electromagnetic force is obtained according to formula (6).

4. The calculation method according to claim 1, characterized in that: In step (4), based on the continuity equation, NS equation, energy equation and state equation in the equation set (7), the pressure of each node in the fluid domain is solved by the finite element method, and then the pressure is substituted into formula (8) to solve the aerodynamic force.

5. The calculation method according to claim 1, characterized in that: The electromagnetic force F in the kinematic equations of step (5) m It is a function of valve core displacement x and solenoid valve operating current i; spring force F k It is a function of the valve core displacement x; aerodynamic force F p It is a function of the valve core displacement x; frictional force F f It is a constant; damping force F v It is a function of velocity.

6. The calculation method according to claim 1, characterized in that: In step (6), the electromagnetic force finite element calculation takes the solenoid valve digital model, coil ampere-turns, material parameters, valve core movement stroke and movement step as inputs, and outputs valve core electromagnetic force-displacement curve data.

7. The calculation method according to claim 1, characterized in that: In step (7), the aerodynamic simulation needs to be pre-calculated before the formal finite element calculation to determine the mesh generation scheme. The completed mesh includes the boundary layer mesh and the internal mesh.

8. The calculation method according to claim 1, characterized in that: Experimental data processing in step (8): The same interpolation matrix is ​​used for L(X,I), F m Interpolate (X,I) to ensure that the array dimensions in step (7) are consistent.

9. The calculation method according to claim 1, characterized in that: In step (9), when solving the system of partial differential equations, it is necessary to constrain the parameter x. j ∈[x min ,x max ], i k ∈[i min i max ].

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