Air spring volume acquisition method, system and electronic equipment

Abstract

The present invention provides a method, system, and electronic device for obtaining the volume of an air spring, wherein the method includes: obtaining the piston inclination angle, initial lug radius, and first and second lengths of the air spring at a reference equilibrium height; determining the lug radius and lug change amount of the air spring after the height change is determined based on the piston inclination angle, initial lug radius, first length, and the height change amount; determining the estimated first and second lengths of the air spring after the change based on the changed lug radius, lug change amount, and the initial first and second lengths; and determining the volume of the air spring after the height change is determined based on the estimated first and second lengths. This method is used to address the drawback of the prior art that the lack of a complete and simple method for predicting the volume of an air spring makes it difficult to study the dynamic characteristics of an air spring at different equilibrium heights, and to achieve prediction of the air spring volume based on the geometric dimensions of the bladder profile.

Description

Technical Field

[0001] The present invention relates to the technical field of air springs, and in particular to a method, system and electronic equipment for obtaining the volume of an air spring. Background Art

[0002] Air springs are increasingly favored by automakers and consumers for their excellent vibration isolation, lightweight design, and adjustable height. Therefore, research on their dynamic characteristics at different equilibrium heights is essential.

[0003] At present, the calculation methods for the volume of air springs mainly focus on geometric diagrams, finite element simulation, experimental fitting, etc. However, the effective prediction and analytical calculation of the dynamic characteristics of this part are still imperfect. For example: when calculating the volume and stiffness of the air spring based on geometry, most of them need to make relevant assumptions about the internal volume of the air spring, and ignore the curvature change at the connection point between the bladder skin and the upper cover plate, while some need to measure some internal parameters of the air spring. However, the measurement of internal parameters is difficult and requires the destruction of the entire structure. At present, there is also a method of measuring volume based on the drainage method. Although this method is accurate and simple, the residual liquid may have a certain impact on the bladder skin and its dynamic characteristics, and it is difficult to measure the volume at all equilibrium positions. Summary of the Invention

[0004] The present invention provides a method, system and electronic device for obtaining the volume of an air spring, so as to solve the defect in the prior art that the dynamic characteristics of the air spring at different equilibrium heights are not convenient to study due to the lack of a complete and simple method for predicting the volume of the air spring, and realize the prediction of the air spring volume based on the geometric dimensions of the bladder skin contour.

[0005] The present invention also provides a method for obtaining the volume of an air spring, comprising:

[0006] Obtaining the piston inclination angle, as well as the lug radius, first length, and second length of the air spring at a reference equilibrium height, and using the lug radius, first length, and second length of the air spring at the reference equilibrium height as the initial lug radius, initial first length, and initial second length, respectively. The piston inclination angle is the angle between the generatrix of the piston and the bottom surface. The first length is the length of the straight section of the air spring bladder away from the piston. The second length is the length of the straight section of the air spring bladder in contact with the piston, along a direction perpendicular to the bottom surface.

[0007] Determining, based on the piston inclination angle, the initial lug radius, the initial first length, and the amount of height change to be made for the air spring, the lug radius and the amount of lug change after the air spring changes according to the amount of height change to be made;

[0008] Based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, respectively determining a first length and a second length of the air spring after the change according to the height change amount, and using these as an estimated first length and an estimated second length, respectively;

[0009] Based on the estimated first length and the estimated second length, a volume of the air spring after changing according to the height change amount is determined.

[0010] According to the method for obtaining the volume of an air spring of the present invention, determining the lug radius and the lug change amount of the air spring after the height is changed by the expected height change based on the piston inclination angle, the initial lug radius, the initial first length, and the expected height change amount of the air spring includes:

[0011] Based on the symmetry of the drop ear and a change trajectory of the center of the drop ear after the air spring changes from the reference equilibrium height by the amount of height change to be determined, and based on the piston inclination angle, the initial drop ear radius, the initial first length, and the amount of height change to be determined, a first and a second relationship between the drop ear radius after the change and the amount of drop ear change are determined;

[0012] The first relational expression and the second relational expression are combined to determine the changed ear drop radius and the ear drop change amount.

[0013] The first relational expression and the second relational expression include:

[0014]

[0015] in, is the piston inclination angle, R S is the initial ear radius, l S is the initial first length, R is the radius of the ear after the change, Δh is the height to be changed, and a is the change amount of the ear.

[0016] According to the method for obtaining the volume of an air spring of the present invention, determining the first length and the second length of the air spring after the height changes by the amount to be changed based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, respectively, includes:

[0017] According to a preset first formula and a preset second formula, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, the first length and the second length of the air spring after the change according to the height to be changed amount are respectively determined, wherein the preset first formula and the preset second formula include:

[0018]

[0019] in, To estimate the first length, and l P They are the estimated second length and the initial second length respectively.

[0020] The method for obtaining the volume of an air spring according to the present invention further includes: a method for determining the second length l2;

[0021] The determination methods include:

[0022] The second length is determined according to a preset third formula based on the outer radius of the bladder skin, the piston inclination angle, the ear radius, and the radius of the bladder skin at the piston retaining ring. The preset third formula includes:

[0023]

[0024] Among them, R A is the outer radius of the capsule, R0 is the radius of the earlobe, R V is the radius of the bladder at the piston fixing ring.

[0025] According to the method for obtaining the volume of an air spring of the present invention, determining the volume of the air spring after the height changes according to the amount to be changed based on the estimated first length and the estimated second length includes:

[0026] Ignore the concave portion of the capsule skin at the bottom surface and regard the capsule skin as a cylinder with rounded edges. Based on the outer radius, ear radius and first length of the capsule skin, determine the volume V of the cylinder. A The calculation formula is:

[0027]

[0028] Wherein, l1 is the first length;

[0029] The volume V of the recessed portion is determined based on the piston inclination angle, the radius of the bladder skin at the piston fixing ring, the outer radius of the bladder skin, the ear radius and the second length. a The calculation formula is:

[0030]

[0031] Based on the estimated first length and the estimated second length, according to the volume V of the cylinder A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume of the air spring after the height changes according to the height change amount.

[0032] According to the method for obtaining the volume of the air spring of the present invention, the volume of the cylinder V is obtained based on the estimated first length and the estimated second length. A The calculation formula and the volume of the concave part V a The calculation formula for determining the volume of the air spring after the height is changed by the amount to be changed includes:

[0033] Based on the cylinder volume V A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume V of the air spring related to the balance height. h The calculation formula is:

[0034] V h =V A -V a

[0035] According to a preset fourth formula, based on the estimated first length and the estimated second length, the volume of the air spring is determined. The preset fourth formula includes:

[0036]

[0037] Among them, V b0 is the volume of the air spring at the reference equilibrium height, and They are respectively the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed amount and the volume of the air spring related to the equilibrium height at the reference equilibrium height.

[0038] The method for obtaining the volume of an air spring according to the present invention further includes: when the piston is of an irregular shape, the radius of the bladder skin at the piston fixing ring, and a method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed;

[0039] The method for obtaining the radius of the bladder skin at the piston fixing ring includes:

[0040] According to the known size of the piston, a virtual point in space is set on the air spring;

[0041] Determining the radius of the bladder skin at the piston fixing ring based on the position of the virtual point in space;

[0042] The method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed includes:

[0043] The volume of the air spring related to the equilibrium height after the height to be changed is calculated by integration based on the geometric shape of the piston:

[0044]

[0045] The present invention also provides a system for obtaining the volume of an air spring, comprising:

[0046] an acquisition module, configured to acquire a piston inclination angle, as well as a lug radius, a first length, and a second length of the air spring at a reference equilibrium height, and use the lug radius, the first length, and the second length of the air spring at the reference equilibrium height as an initial lug radius, an initial first length, and an initial second length, respectively; the piston inclination angle being the angle between the generatrix of the piston and the bottom surface; the first length being the length of a straight section of the air spring bladder away from one side of the piston; and the second length being the length of a straight section of the air spring bladder in contact with one side of the piston, along a direction perpendicular to the bottom surface;

[0047] a first prediction module, configured to determine, based on the piston inclination angle, the initial lug radius, the initial first length, and the amount of height change to be made of the air spring, the lug radius and the amount of lug change of the air spring after the air spring changes according to the amount of height change to be made;

[0048] a second prediction module for determining, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, a first length and a second length of the air spring after the height change by the amount to be changed, and using these as an estimated first length and an estimated second length, respectively;

[0049] A third prediction module is configured to determine a volume of the air spring after the volume changes according to the height change amount based on the estimated first length and the estimated second length.

[0050] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for obtaining the volume of an air spring as described above is implemented.

[0051] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for obtaining the volume of an air spring as described above is implemented.

[0052] The present invention provides a method, system, and electronic device for obtaining the volume of an air spring. First, the method determines the lug radius and lug change of the air spring after the height change is determined based on the piston inclination angle of the air spring, the initial lug radius at a reference equilibrium height, the initial first length of the straight section of the bladder skin away from the piston, and the expected height change of the air spring. Then, based on the changed lug radius, the lug change, the initial first length, and the initial second length of the straight section of the bladder skin contacting the piston in a direction perpendicular to the bottom surface, the method determines the estimated first and second lengths of the air spring after the height change is determined. Finally, based on the estimated first and second lengths, the volume of the air spring after the height change is determined. This method enables estimating the volume of an air spring based on its external dimensions, making air spring volume estimation simple, easy to implement, and universally applicable. Furthermore, it provides a foundation for the forward development of air springs and the accurate prediction of volume and dynamic stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 1 is a flow chart of a method for obtaining the volume of an air spring provided in an embodiment of the present invention;

[0055] Figure 2 1 is a schematic structural diagram of an air spring provided by an embodiment of the present invention;

[0056] Figure 3 Schematic diagram of the structure of an air suspension system test bench provided by an embodiment of the present invention;

[0057] Figure 4 is the hysteresis characteristic curve of the air spring;

[0058] Figure 5 : is a comparative relationship diagram of the theoretical value and experimental value of the real part of the dynamic stiffness of the air spring at different positions under 0.01 Hz excitation provided by an embodiment of the present invention;

[0059] Figure 6 : is a comparative relationship diagram of the theoretical value and the experimental value of the imaginary part of the dynamic stiffness of the air spring at different positions under 0.01 Hz excitation provided by an embodiment of the present invention;

[0060] Figure 7: is a comparative relationship diagram of the theoretical value and experimental value of the real part of the dynamic stiffness of the air spring at different positions under 1 Hz excitation provided by an embodiment of the present invention;

[0061] Figure 8 : is a comparative relationship diagram of the theoretical value and the experimental value of the imaginary part of the dynamic stiffness of the air spring at different positions under 1 Hz excitation provided by an embodiment of the present invention;

[0062] Figure 9 This is a comparison diagram of the theoretical value and experimental value of the equivalent damping of the air spring at different positions provided by an embodiment of the present invention;

[0063] Figure 10 1 is a schematic structural diagram of a system for obtaining the volume of an air spring provided in an embodiment of the present invention;

[0064] Figure 11 It is a structural schematic diagram of the electronic device provided by the present invention.

[0065] Reference numerals:

[0066] 1: High-pressure gas source; 2: High-pressure gas pipe; 3: Pressure reducing valve; 4: Pressure sensor; 5: Membrane air spring; 6: Actuator; 7: Force sensor; 8: Data acquisition equipment. DETAILED DESCRIPTION

[0067] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0068] First, to facilitate understanding of the acquisition method described in the present invention, we will first introduce the air spring involved in this invention. A membrane-type rubber air spring is a flexible body formed by molding and vulcanizing a cord layer and inner and outer rubber layers. It utilizes the compressibility of filled air to achieve its elastic function. Commonly known as an air spring, rubber airbag, or airbag, it is a rubber element.

[0069] The following combination Figures 1 to 9 A method for obtaining the volume of an air spring according to the present invention is described, wherein the method is executed by a computer or a combination of software and / or hardware therein, such as Figure 1 As shown, the method includes the following steps:

[0070] 101. Obtain a piston inclination angle of the air spring, as well as a lug radius, a first length, and a second length at a reference equilibrium height. The lug radius, the first length, and the second length of the air spring at the reference equilibrium height are used as an initial lug radius, an initial first length, and an initial second length, respectively.

[0071] Specifically, the piston inclination angle is the angle between the center line of the piston and the bottom surface, the first length is the length of the straight section of the air spring bladder away from the side of the piston, and the second length is the length of the straight section of the bladder skin that is attached to the side of the piston in the direction perpendicular to the bottom surface.

[0072] It is understandable that Figure 2 The diagram below is a schematic diagram of the air spring structure, on which the key dimensions of the air spring are marked. Figure 2 As shown, the piston inclination angle of the air spring, the length of the straight section of the bladder skin away from the piston side, and the length of the straight section of the bladder skin on the piston side along the direction perpendicular to the bottom surface are all parameters that can be directly obtained by measuring outside the air spring.

[0073] More specifically, the reference equilibrium height can be any equilibrium height of the air spring, preferably the equilibrium height in the initial state, that is, the equilibrium height of the air spring when no external force is applied. At this time, the total volume V of the air spring can be obtained by methods such as the water displacement method. b0 .

[0074] 102. Determine, based on the piston inclination angle, the initial lug radius, the initial first length, and the expected height change of the air spring, the lug radius and the lug change amount of the air spring after the height change is changed according to the expected height change amount;

[0075] Specifically, if Figure 2 The figure shows a schematic diagram of an air spring, where the left half shows the key dimensions and the rubber bladder contour definition and schematic diagram at different heights, and the dotted area on the right half shows the corresponding volume definition. AS The sum of the displacement vector z is positive when it points upward; increasing pressure p, temperature T, volume V, and gas mass m are positive; the subscript atm represents the ambient air; and h represents the height of the air spring. While maintaining constant pressure, when the air spring is adjusted and moves downward during height adjustment, the entire bladder moves downward. Based on the relationship between the angle and position of the air spring before and after the equilibrium height change, the air spring's piston inclination angle, initial lug radius, initial first length, and the amount of height change to be determined, the lug radius R and lug change a after the air spring changes according to the amount of height change to be determined can be determined.

[0076] 103. Based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, respectively determine a first length and a second length of the air spring after the change according to the height change amount, and use them as an estimated first length and an estimated second length, respectively;

[0077] Specifically, after determining the lug radius and lug change amount after the air spring changes according to the height to be changed, based on the relationship between the lengths before and after the air spring balance height changes, the first length and second length of the air spring after changing according to the height to be changed can be determined based on the changed lug radius, lug change amount, initial first length and initial second length.

[0078] 104. Determine a volume of the air spring after the volume changes according to the height change amount based on the estimated first length and the estimated second length.

[0079] Specifically, after determining the estimated first length and the estimated second length, that is, the length of the straight section of the bladder skin away from the piston side after the air spring changes according to the height to be changed, and the length of the straight section of the bladder skin on the piston side along the vertical bottom surface direction, the volume of the air spring at the new equilibrium height after the height changes from the reference equilibrium height according to the height to be changed can be calculated.

[0080] The method for obtaining air spring volume provided by the embodiments of this invention enables volume estimation based on external dimensions such as the air spring's piston inclination angle and lug radius. This makes air spring volume estimation simple, easy to implement, and universally applicable. Furthermore, it provides a foundation for the forward development of air springs and the accurate prediction of volume and dynamic stiffness.

[0081] In some embodiments, determining the lug radius and the lug change amount of the air spring after the height change is changed according to the expected height change based on the piston inclination angle, the initial lug radius, the initial first length, and the expected height change of the air spring includes:

[0082] Based on the symmetry of the drop ear and a change trajectory of the center of the drop ear after the air spring changes from the reference equilibrium height by the amount of height change to be determined, and based on the piston inclination angle, the initial drop ear radius, the initial first length, and the amount of height change to be determined, a first and a second relationship between the drop ear radius after the change and the amount of drop ear change are determined;

[0083] The first relational expression and the second relational expression are combined to determine the changed ear drop radius and the ear drop change amount.

[0084] The first relational expression and the second relational expression include:

[0085]

[0086] in, is the piston inclination angle, R S is the initial ear radius, l S is the initial first length, R is the radius of the ear after the change, Δh is the height to be changed, and a is the change amount of the ear.

[0087] Specifically, after determining the first and second relationship formulas for the changed ear radius and the ear change amount, i.e., Formulas 1 and 2, by combining Formulas 1 and 2, the expressions for a and R can be obtained respectively:

[0088]

[0089]

[0090] More specifically, by substituting the obtained parameters such as the piston inclination angle and inclination radius into Formulas 3 and 4, the changed drop ear radius and the drop ear change amount can be calculated.

[0091] In some embodiments, determining the first length and the second length of the air spring after the height is changed by the amount of the height to be changed based on the changed drop ear radius, the amount of the drop ear change, the initial first length, and the initial second length, respectively, includes:

[0092] According to a preset first formula and a preset second formula, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, the first length and the second length of the air spring after the change according to the height to be changed amount are respectively determined, wherein the preset first formula and the preset second formula include:

[0093]

[0094] in, To estimate the first length, and l P They are the estimated second length and the initial second length respectively.

[0095] Specifically, through Figure 2 The relationship between the key parameters of the air spring shown can be used to obtain a preset first formula and a preset second formula for calculating the first length and the second length of the air spring after the height changes according to the height change amount.

[0096] In other embodiments, the method for obtaining the volume of the air spring provided by the present invention further includes: a method for determining the second length l2;

[0097] The determination methods include:

[0098] The second length is determined according to a preset third formula based on the outer radius of the bladder skin, the piston inclination angle, the ear radius, and the radius of the bladder skin at the piston retaining ring. The preset third formula includes:

[0099]

[0100] Among them, R A is the outer radius of the capsule, R0 is the radius of the earlobe, R V is the radius of the bladder at the piston fixing ring.

[0101] Specifically, based on Figure 2 The relationship between the various shape parameters of the air spring shown can be used to obtain a preset third formula for calculating the second length.

[0102] In some embodiments, determining the volume of the air spring after the height is changed by the amount to be changed based on the estimated first length and the estimated second length includes:

[0103] Ignore the concave portion of the capsule skin at the bottom surface and regard the capsule skin as a cylinder with rounded edges. Based on the outer radius, ear radius and first length of the capsule skin, determine the volume V of the cylinder. A The calculation formula is:

[0104]

[0105] Wherein, l1 is the first length;

[0106] The volume V of the recessed portion is determined based on the piston inclination angle, the radius of the bladder skin at the piston fixing ring, the outer radius of the bladder skin, the ear radius and the second length. a The calculation formula is:

[0107]

[0108] Based on the estimated first length and the estimated second length, according to the volume V of the cylinder A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume of the air spring after the height changes according to the height change amount.

[0109] Specifically, when ignoring Figure 2 After the concave part of the bottom of the air spring is shown, the air spring can be regarded as Figure 2 In the figure, V1, V2, V3 and V4 are composed of a cylinder with rounded edges. According to Figure 2 The shape parameters marked in , we can get the volume of the cylinder as:

[0110]

[0111]

[0112] And by Figure 2 It can be seen that Therefore, the volume of the concave part V a It can be expressed by formula 9.

[0113] Furthermore, the volume of the air spring at any equilibrium height can be obtained through Formula 9 and Formula 10. Then, after the estimated first length and the estimated second length are known, the volume of the air spring after the height changes according to the amount to be changed can be determined.

[0114] In some embodiments, the volume V of the cylinder is determined based on the estimated first length and the estimated second length. A The calculation formula and the volume of the concave part V a The calculation formula for determining the volume of the air spring after the height is changed by the amount to be changed includes:

[0115] Based on the cylinder volume V A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume V of the air spring related to the balance height. h The calculation formula is:

[0116] V h =V A -V a (11)

[0117] According to a preset fourth formula, based on the estimated first length and the estimated second length, the volume of the air spring is determined. The preset fourth formula includes:

[0118]

[0119] Among them, V b0 is the volume of the air spring at the reference equilibrium height, and They are respectively the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed amount and the volume of the air spring related to the equilibrium height at the reference equilibrium height.

[0120] Specifically, as mentioned above, the volume V of the air spring at the reference equilibrium height is b0 It can be obtained by drainage method and other methods. Therefore, when V b0When the height of the air spring is known, the volume of the air spring after the height is changed by the amount to be changed can be obtained by simply calculating the volume difference between the air spring before and after the height is changed.

[0121] More specifically, by substituting formula 9, formula 10, etc. into formula 12, it can be found that The outer radius R of the capsule can be A , the ear radius R of the air spring at the reference equilibrium height S , initial first length l S The shape parameters can be directly measured and calculated without destroying the air spring structure.

[0122] In some embodiments, the method for obtaining the volume of the air spring provided by the present invention further includes: when the piston is of an irregular shape, the radius of the bladder skin at the piston fixing ring, and a method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed;

[0123] The method for obtaining the radius of the bladder skin at the piston fixing ring includes:

[0124] According to the known size of the piston, a virtual point in space is set on the air spring;

[0125] Determining the radius of the bladder skin at the piston fixing ring based on the position of the virtual point in space;

[0126] The method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed includes:

[0127] The volume of the air spring related to the equilibrium height after the height to be changed is calculated by integration based on the geometric shape of the piston:

[0128]

[0129] Specifically, if R V If it is unknown or difficult to measure, R can be calculated based on the known piston size and the position of the virtual point in space. V For an irregular piston, the volume of the air spring related to the equilibrium height after the height to be changed is calculated by integration based on the geometric shape, that is, the geometric profile of the piston.

[0130] The method for obtaining the volume of an air spring provided in an embodiment of the present invention proposes a method for predicting the volume of an air spring at different equilibrium heights based on the volume of the air spring at a reference equilibrium height and the outline dimensions of the bladder, making the volume prediction of the air spring simple and easy to implement.

[0131] Next, by building an air spring dynamometer test platform and a pneumatic system, the accuracy of the air spring volume obtained by the air spring volume acquisition method provided by the above embodiment of the present invention, as well as the relationship between the air spring volume and dynamic stiffness are verified, thereby providing a theoretical basis for the forward development of air springs.

[0132] The principle of the pneumatic system is as follows Figure 3 As shown, specifically, gas flows from a high-pressure gas source 1 through a high-pressure gas pipe 2, a pressure reducing valve 3, and a pressure sensor 4 to an air spring 5; an actuator 6 excites the air spring 5 with a sinusoidal displacement, and a force sensor 7 detects the force generated by the excitation; the pressure reducing valve 3 controls the internal air pressure of the air spring 5, and a data acquisition device 8 collects data from the actuator 6 and the force sensor 7, respectively. The equilibrium height of the air spring 5 is controlled by a hydraulic rod. In the dynamometer test, the air spring state h0 = 0.292m, P b0 = 9.0 bar (absolute pressure) as the reference state for analysis. In the tests with the same pressure and different equilibrium heights, the height variation was ±20 and ±10 mm (compression is positive), the excitation amplitudes A were 0.1, 0.5, 1, 2, 5, and 10 mm, and the frequencies f were 0.005, 0.01, 0.02, 0.05, 0.1, 0.5, 1, and 5 Hz, respectively.

[0133] It is understood that the dynamic characteristics of air springs are mainly composed of two parts: high-pressure gas and rubber bladder. Among them, the dynamic characteristics caused by high-pressure gas, based on the Chinese invention patent application with publication number CN114444328A, mainly consider the stiffness k generated by the change of effective area. A , the stiffness k1 generated by the internal high-pressure gas and the equivalent damping c1 generated by heat exchange:

[0134]

[0135] At the same time, it is known that:

[0136]

[0137] Among them, C V is the specific heat of air at constant volume, A eff is the effective area, K b is the heat exchange coefficient, γ is the polytropic index, and the subscript b0 represents the initial state of the air bag.

[0138] Furthermore, the influence of the rubber bladder on the dynamic stiffness of the air spring K2 mainly considers the Payne effect of the rubber-cord reinforced composite material, that is, the characteristic that the dynamic stiffness increases sharply with the decrease of the excitation amplitude.

[0139] Specifically, it is assumed that the variation of the dynamic stiffness of the bladder structure with amplitude conforms to the variation of the dynamic stiffness of the rubber material modulus with strain, and the oscillatory simple harmonic strain of the rubber material is assumed to be:

[0140] ε(t)=ε0e jωt =ε0(cosωt+j sinωt) (16)

[0141] Where ε0 is the strain amplitude and ω is the strain angular velocity.

[0142] Due to the viscoelastic hysteresis effect of rubber, its complex modulus (dynamic modulus) can be written as:

[0143]

[0144] Where σ0 is the stress and δ is the hysteresis angle.

[0145] Furthermore, the complex modulus of the rubber material can be decomposed into real and imaginary parts:

[0146]

[0147] Among them, G' is called the storage modulus, which is proportional to the maximum energy stored per unit material in each cycle, and G" is the loss modulus, which represents the irreversible energy loss and viscous loss heat generated by shear and friction per unit material in the cycle. The Kraus model based on the dynamic modulus of rubber is:

[0148]

[0149]

[0150] Among them, ε c is the characteristic strain, which is a certain value; m represents a constant related to the fractal dimension of the rubber material and the carbon black structure, G″ M is the maximum value of the loss modulus from zero strain to infinite strain.

[0151] Assuming the dynamic stiffness of the bladder structure conforms to the Kraus model and its assumptions for rubber materials, the displacement excitation amplitude A experienced by the air spring is proportional to the strain amplitude ε0 of the bladder. Experiments demonstrating the dynamic stiffness of rubber materials as a function of amplitude show that the value of m is approximately 0.5 and is independent of the type of carbon black. Equations 19 and 20 provide the expressions for the real part K′ and imaginary part K″ of the dynamic stiffness of the airbag structure, as a function of the excitation amplitude:

[0152]

[0153]

[0154] Among them, A c is the characteristic amplitude, which is a constant value. Combining Equations 14, 15, 21, and 22, we can obtain the decoupling expression of the air spring dynamic stiffness K(ω):

[0155]

[0156] Equation 23 shows that the real part of the air spring's dynamic stiffness is primarily composed of the real part of the bladder's dynamic stiffness, representing the degree of energy storage; the stiffness due to the height-dependent change in effective area; the gas stiffness; and the equivalent damping due to heat exchange. The imaginary part is primarily composed of the imaginary part of the bladder's dynamic stiffness, representing the degree of loss; and the gas parameters. The rubber bladder exhibits amplitude dependence, independent of the excitation frequency; while the stiffness and equivalent damping due to the gas are only frequency-dependent. This decoupling allows for the clear contribution of each component to the total stiffness.

[0157] It is known that the power curve of the air spring is as follows Figure 4 The hysteresis curve area S and the maximum value can be used to calculate the hysteresis angle μ and the real part k of the dynamic stiffness. Re and the imaginary part k Im , that is, the test value of the dynamic stiffness of the air spring:

[0158]

[0159] By substituting the calculation formula of the air spring volume derived from the method for obtaining the air spring volume provided by the embodiment of the present invention into the above formula 23, the dynamic characteristics of the air spring under different equilibrium height conditions under the same pressure, that is, the theoretical value of the dynamic stiffness of the air spring, can be calculated.

[0160] like Figure 5 and Figure 6 As shown in the figure, they are the relationship between the theoretical value and the experimental value of the real and imaginary parts of the dynamic stiffness at different equilibrium heights under 0.01Hz excitation; Figure 7 and Figure 8 As shown in the figure, they are the relationship between the theoretical value and the experimental value of the real and imaginary parts of the dynamic stiffness at different positions under 1 Hz excitation, where: Figures 5 to 7 The curves in the figure represent the theoretical values ​​when the height change is 20mm, 10mm, 0mm, -10mm and -20mm respectively. Figure 8 The curves in the figure represent the theoretical values ​​when the height change is 10mm, 20mm, -10mm, -20mm and 0mm respectively. Figure 9As shown, it is a relationship diagram between the theoretical value and the experimental value of the equivalent damping at different positions, wherein the curves represent the theoretical values ​​when the height change amount is 10mm, 0mm, 20mm, -10mm and -20mm from top to bottom, respectively, and the dots in each figure represent the experimental values. It can be seen that the variation pattern of the theoretical value is basically consistent with the experimental value, that is, the relevant design parameters identified based on the experiment are consistent with the measured values, which verifies the correctness of the volume of the air spring obtained by the air spring volume acquisition method provided by the embodiment of the present invention. At the same time, it can also be seen that the dynamic stiffness of the air spring shows volume correlation and excitation amplitude-frequency correlation, and the influence of the rubber bladder skin on the dynamic stiffness at low amplitude cannot be ignored. The internal gas polynomial index is positively correlated with the excitation frequency and increases with the increase of the equilibrium height; the heat exchange equivalent damping decreases with the increase of the excitation frequency and the equilibrium height.

[0161] In summary, the method for obtaining the volume of an air spring provided in an embodiment of the present invention proposes a theory of dynamic characteristics of different working conditions based on the design parameters of the air spring, which can provide guidance for the forward design and engineering application of the air spring.

[0162] The following combination Figure 10 A system for obtaining the volume of an air spring provided by the present invention is described. The system for obtaining the volume of an air spring described below and the method for obtaining the volume of an air spring described above can refer to each other.

[0163] like Figure 10 As shown, the present invention provides an air spring volume acquisition system, comprising: an acquisition module 110, a first prediction module 120, a second prediction module 130 and a third prediction module 140; wherein,

[0164] The acquisition module 110 is configured to acquire the piston inclination angle, as well as the lug radius, first length, and second length of the air spring at a reference equilibrium height, and use the lug radius, first length, and second length of the air spring at the reference equilibrium height as the initial lug radius, initial first length, and initial second length, respectively. The piston inclination angle is the angle between the generatrix of the piston and the bottom surface. The first length is the length of a straight section of the air spring bladder away from one side of the piston. The second length is the length of the straight section of the air spring bladder in contact with the piston, along a direction perpendicular to the bottom surface.

[0165] The first prediction module 120 is configured to determine the lug radius and lug change amount of the air spring after the height change is changed according to the expected height change based on the piston inclination angle, the initial lug radius, the initial first length, and the expected height change amount of the air spring;

[0166] The second prediction module 130 is configured to determine, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, a first length and a second length of the air spring after the height change by the amount to be changed, and use them as an estimated first length and an estimated second length, respectively;

[0167] The third prediction module 140 is configured to determine a volume of the air spring after the volume changes according to the height change amount based on the estimated first length and the estimated second length.

[0168] Specifically, the air spring volume acquisition system provided in an embodiment of the present invention first determines the air spring's lug radius and lug change amount after the height change due to the air spring's expected height change by obtaining the air spring's piston inclination angle, the initial lug radius at a reference equilibrium height, the initial first length of the straight section of the bladder skin away from the piston, and the air spring's expected height change amount. Then, based on the changed lug radius, the lug change amount, the initial first length, and the initial second length of the straight section of the bladder skin contacting the piston along a direction perpendicular to the bottom surface, the system determines the estimated first and second lengths of the air spring after the height change due to the expected height change amount. Finally, based on the estimated first and second lengths, the air spring's volume after the height change due to the expected height change amount is determined. This method enables estimating the air spring's volume based on its external dimensions, making air spring volume estimation simple, easy to implement, and universally applicable. It also provides a foundation for the forward development of air springs and the accurate prediction of their volume and dynamic stiffness.

[0169] Preferably, the first prediction module is specifically configured to determine, based on the symmetry of the drop ear and a trajectory of a change in the center of the drop ear after the air spring changes from the reference equilibrium height by the amount of height change to be determined, the piston inclination angle, the initial drop ear radius, the initial first length, and the amount of height change to be determined, a first relational expression and a second relational expression between a post-change drop ear radius and a post-change drop ear variation, as shown in Formulas 1 and 2. The first and second relational expressions are then established in parallel to determine the post-change drop ear radius and the post-change drop ear variation.

[0170] Preferably, the second prediction module is specifically used to determine the first length and the second length of the air spring after the height changes according to the preset first formula and the preset second formula shown in Formula 5 and Formula 6, based on the changed drop ear radius, the drop ear change amount, the initial first length and the initial second length.

[0171] It is further preferred that the air spring volume acquisition system provided by the embodiment of the present invention further includes: a second length determination module;

[0172] The second length determination module is used to determine the second length based on the outer radius of the bladder skin, the piston inclination angle, the ear radius and the radius of the bladder skin at the piston fixing ring according to a preset third formula as shown in Formula 7.

[0173] More preferably, the third prediction module is specifically configured to ignore the concave portion of the capsule skin at the bottom surface, regard the capsule skin as a cylinder with rounded edges, and determine the volume V of the cylinder as shown in Formula 8 based on the outer radius, the ear radius, and the first length of the capsule skin. A Based on the piston inclination angle, the radius of the bladder skin at the piston fixing ring, the outer radius of the bladder skin, the ear radius and the second length, the volume V of the recessed portion as shown in Formula 9 is determined. a The calculation formula, and based on the estimated first length and the estimated second length, according to the volume V of the cylinder A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume of the air spring after the height changes according to the height change amount.

[0174] Preferably, the third prediction module is more specifically configured to: A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume V of the air spring related to the equilibrium height as shown in Formula 11. h The volume of the air spring is determined based on the estimated first length and the estimated second length according to the preset fourth formula shown in formula 12.

[0175] Preferably, the acquisition module is further configured to acquire, when the piston is of an irregular shape, the radius of the bladder skin at the piston fixing ring, and the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed amount;

[0176] The acquisition module is specifically used to set a spatial virtual point on the air spring according to the known size of the piston; and determine the radius of the air spring at the piston fixing ring based on the position of the spatial virtual point;

[0177] And for the piston with an irregular shape, the volume change of the air spring related to the equilibrium height after the height to be changed is calculated according to the geometric shape of the piston using the integral shown in the above formula 13.

[0178] Figure 11 An example of a physical structure diagram of an electronic device is shown below. Figure 11As shown, the electronic device may include: a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112 and the memory 113 communicate with each other via the communication bus 114. The processor 111 may call the logic instructions in the memory 113 to execute a method for obtaining the volume of an air spring, the method comprising: obtaining the piston inclination angle of the air spring, as well as the ear radius, the first length and the second length at the reference equilibrium height, and using the ear radius, the first length and the second length of the air spring at the reference equilibrium height as the initial ear radius, the initial first length and the initial second length respectively, the piston inclination angle being the angle between the generatrix and the bottom surface of the piston, the first length being the length of the straight section of the air spring bladder away from one side of the piston, and the second length being the length of the straight section of the bladder bladder attached to one side of the piston along the vertical direction. The length in the bottom surface direction; based on the piston inclination angle, the initial ear radius, the initial first length, and the amount of change in the height of the air spring, determine the ear radius and the ear change amount of the air spring after the height changes according to the amount of change; based on the changed ear radius, the ear change amount, the initial first length, and the initial second length, respectively determine the first length and the second length of the air spring after the height changes according to the amount of change, and use them as the estimated first length and the estimated second length, respectively; based on the estimated first length and the estimated second length, determine the volume of the air spring after the height changes according to the amount of change.

[0179] In addition, the logic instructions in the above-mentioned memory 113 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0180] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the air spring volume acquisition method provided by the above methods, the method including: obtaining the piston inclination angle of the air spring, as well as the ear radius, first length and second length at the reference equilibrium height, and using the ear radius, first length and second length of the air spring at the reference equilibrium height as the initial ear radius, initial first length and initial second length respectively, the piston inclination angle is the angle between the center line of the piston and the bottom surface, and the first length is the straight section of the air spring bladder away from the side of the piston. , the second length is the length of the straight section of the bladder skin that fits against the side of the piston in a direction perpendicular to the bottom surface; based on the piston inclination angle, the initial ear radius, the initial first length, and the amount of height to be changed of the air spring, determine the ear radius and the ear change amount of the air spring after the height changes according to the amount of height to be changed; based on the changed ear radius, the ear change amount, the initial first length, and the initial second length, respectively determine the first length and the second length of the air spring after the height changes according to the amount of height to be changed, and use them as the estimated first length and the estimated second length, respectively; based on the estimated first length and the estimated second length, determine the volume of the air spring after the height changes according to the amount of height to be changed.

[0181] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for obtaining the volume of an air spring provided by the above-mentioned methods, the method comprising: obtaining the piston inclination angle of the air spring, and the ear radius, first length and second length at a reference equilibrium height, and using the ear radius, first length and second length of the air spring at the reference equilibrium height as the initial ear radius, initial first length and initial second length respectively, the piston inclination angle is the angle between the generatrix and the bottom surface of the piston, the first length is the length of the straight section of the air spring bladder skin away from the piston side, and the second length is the length of the straight section of the bladder skin close to the piston. The length of the straight section on one side of the piston along the direction perpendicular to the bottom surface; based on the piston inclination angle, the initial ear radius, the initial first length, and the amount of height to be changed of the air spring, determine the ear radius and the ear change amount of the air spring after the height changes according to the amount to be changed; based on the changed ear radius, the ear change amount, the initial first length and the initial second length, respectively determine the first length and the second length of the air spring after the height changes according to the amount to be changed, and use them as the estimated first length and the estimated second length respectively; based on the estimated first length and the estimated second length, determine the volume of the air spring after the height changes according to the amount to be changed.

[0182] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0183] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for obtaining the volume of an air spring, characterized in that: include: Obtaining the piston inclination angle, as well as the lug radius, first length, and second length of the air spring at a reference equilibrium height, and using the lug radius, first length, and second length of the air spring at the reference equilibrium height as the initial lug radius, initial first length, and initial second length, respectively. The piston inclination angle is the angle between the generatrix of the piston and the bottom surface. The first length is the length of the straight section of the air spring bladder away from the piston. The second length is the length of the straight section of the air spring bladder in contact with the piston, along a direction perpendicular to the bottom surface. Determining, based on the piston inclination angle, the initial lug radius, the initial first length, and the amount of height change to be made for the air spring, the lug radius and the amount of lug change after the air spring changes according to the amount of height change to be made; Based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, respectively determining a first length and a second length of the air spring after the change according to the height change amount, and using these as an estimated first length and an estimated second length, respectively; Based on the estimated first length and the estimated second length, a volume of the air spring after changing according to the height change amount is determined.

2. The method for obtaining the volume of an air spring according to claim 1, characterized in that: The step of determining the lug radius and the lug change amount of the air spring after the air spring changes according to the height change amount based on the piston inclination angle, the initial lug radius, the initial first length, and the height change amount of the air spring includes: Based on the symmetry of the drop ear and a change trajectory of the center of the drop ear after the air spring changes from the reference equilibrium height by the amount of height change to be determined, and based on the piston inclination angle, the initial drop ear radius, the initial first length, and the amount of height change to be determined, a first and a second relationship between the drop ear radius after the change and the amount of drop ear change are determined; The first relational expression and the second relational expression are combined to determine the changed ear drop radius and the ear drop change amount. The first relational expression and the second relational expression include: in, is the piston inclination angle, R S is the initial ear radius, l S is the initial first length, R is the radius of the ear after the change, Δh is the height to be changed, and a is the change amount of the ear.

3. The method for obtaining the volume of an air spring according to claim 2, characterized in that: The determining, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, respectively, of the first length and the second length of the air spring after the change according to the height change amount includes: According to a preset first formula and a preset second formula, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, the first length and the second length of the air spring after the change according to the height to be changed amount are respectively determined, wherein the preset first formula and the preset second formula include: in, To estimate the first length, and l P They are the estimated second length and the initial second length respectively.

4. The method for obtaining the volume of an air spring according to claim 3, characterized in that: Also includes: A method for determining the second length l2; The determination methods include: The second length is determined according to a preset third formula based on the outer radius of the bladder skin, the piston inclination angle, the ear radius, and the radius of the bladder skin at the piston retaining ring. The preset third formula includes: Among them, R A is the outer radius of the capsule, R0 is the radius of the earlobe, R V is the radius of the bladder at the piston fixing ring.

5. The method for obtaining the volume of an air spring according to claim 4, characterized in that: The determining, based on the estimated first length and the estimated second length, the volume of the air spring after the volume changes according to the height to be changed, includes: Ignore the concave portion of the capsule skin at the bottom surface and regard the capsule skin as a cylinder with rounded edges. Based on the outer radius, ear radius and first length of the capsule skin, determine the volume V of the cylinder. A The calculation formula is: Where l1 is the first length; The volume V of the recessed portion is determined based on the piston inclination angle, the radius of the bladder skin at the piston fixing ring, the outer radius of the bladder skin, the ear radius and the second length. a The calculation formula is: Based on the estimated first length and the estimated second length, according to the volume V of the cylinder A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume of the air spring after the height changes according to the height change amount.

6. The method for obtaining the volume of an air spring according to claim 5, characterized in that: The first length and the second length are estimated based on the volume V of the cylinder. A The calculation formula and the volume of the concave part V a The calculation formula for determining the volume of the air spring after the height is changed by the amount to be changed includes: Based on the cylinder volume V A The calculation formula and the volume of the concave part V a The calculation formula is used to determine the volume V of the air spring related to the balance height. h The calculation formula is: V h =V A -V a According to a preset fourth formula, based on the estimated first length and the estimated second length, the volume of the air spring is determined. The preset fourth formula includes: Among them, V b0 is the volume of the air spring at the reference equilibrium height, and They are respectively the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed amount and the volume of the air spring related to the equilibrium height at the reference equilibrium height.

7. The method for obtaining the volume of an air spring according to claim 5, characterized in that: Also includes: When the piston is of an irregular shape, the radius of the bladder skin at the piston fixing ring, and a method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed; The method for obtaining the radius of the bladder skin at the piston fixing ring includes: According to the known size of the piston, a virtual point in space is set on the air spring; Determining the radius of the bladder skin at the piston fixing ring based on the position of the virtual point in space; The method for obtaining the volume of the air spring related to the equilibrium height after the air spring changes according to the height to be changed includes: The volume of the air spring related to the equilibrium height after the height to be changed is calculated by integration based on the geometric shape of the piston:

8. A system for obtaining the volume of an air spring, characterized in that: include: an acquisition module, configured to acquire a piston inclination angle, as well as a lug radius, a first length, and a second length of the air spring at a reference equilibrium height, and use the lug radius, the first length, and the second length of the air spring at the reference equilibrium height as an initial lug radius, an initial first length, and an initial second length, respectively; the piston inclination angle being the angle between the generatrix of the piston and the bottom surface; the first length being the length of a straight section of the air spring bladder away from one side of the piston; and the second length being the length of a straight section of the air spring bladder in contact with one side of the piston, along a direction perpendicular to the bottom surface; a first prediction module, configured to determine, based on the piston inclination angle, the initial lug radius, the initial first length, and the amount of height change to be made of the air spring, the lug radius and the amount of lug change of the air spring after the air spring changes according to the amount of height change to be made; a second prediction module for determining, based on the changed drop ear radius, the drop ear change amount, the initial first length, and the initial second length, a first length and a second length of the air spring after the height change by the amount to be changed, and using these as an estimated first length and an estimated second length, respectively; A third prediction module is configured to determine a volume of the air spring after the volume changes according to the height change amount based on the estimated first length and the estimated second length.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for obtaining the volume of the air spring according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for obtaining the volume of an air spring according to any one of claims 1 to 7 is implemented.

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