Calculation method of vertical stiffness of multi-stage variable center diameter combined helical spring

Abstract

The present invention relates to a method for calculating the vertical stiffness of a multi-section variable center diameter combined coil spring, and belongs to the technical field of vehicle suspension coil springs. The present invention can calculate the vertical stiffness of a multi-section variable center diameter combined coil spring according to the structural parameters and material characteristic parameters of the multi-section variable center diameter combined coil spring, that is, according to the wire diameter of the coil spring, the number of variable center diameter sections, the effective number of turns and effective height of each variable center diameter section, the center diameter of the head end of each variable center diameter section and the center diameter of the end of the coil spring. Through ANSYS simulation and experimental verification of the prototype, it can be known that the method can obtain accurate and reliable calculation values ​​of the vertical stiffness of the multi-section variable center diameter combined coil spring, ensure that the vertical stiffness of the coil spring meets the design requirements, and lay a reliable technical foundation for the design of key parameters of the coil spring, which can improve the product design level and performance, and improve the driving smoothness of the vehicle; at the same time, it also reduces the design and testing costs and speeds up product development.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle suspension coil springs, and in particular to a method for calculating the vertical stiffness of a multi-stage variable center diameter combined coil spring. Background Art

[0002] With the rapid development of vehicles and the continuous increase in driving speed, higher requirements are placed on the performance and design of vehicle suspension springs. In order to meet the design requirements of the installation space of vehicle suspension coil springs, multi-stage variable center diameter combined coil springs are sometimes used. However, since the vertical stiffness calculation of multi-stage variable center diameter coil springs is very complicated, there is no reliable method for calculating the vertical stiffness of multi-stage variable center diameter combined coil springs in the prior art at home and abroad. With the continuous increase in vehicle driving speed and the requirements for driving stability and safety, higher requirements are placed on the design of vehicle suspension coil springs. Therefore, establishing an accurate and reliable method for calculating the vertical stiffness of multi-stage variable center diameter combined coil springs lays a reliable technical foundation for the forward development and design of multi-stage variable center diameter combined coil springs, thereby improving the design level and performance of the product and meeting the design requirements of vehicle driving stability and safety; at the same time, it reduces the design and testing costs of the product and speeds up product development. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for calculating the vertical stiffness of a multi-stage variable center diameter combined helical spring.

[0004] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0005] A method for calculating the vertical stiffness of a multi-section variable mid-diameter combined coil spring, wherein the coil spring is composed of a plurality of variable mid-diameter sections, and the vertical stiffness of the multi-section variable mid-diameter combined coil spring is calculated according to the structural parameters and material characteristic parameters of the multi-section variable mid-diameter combined coil spring, comprising the following steps:

[0006] S1: Horizontal projection length L of each variable diameter section of the multi-section variable diameter combined coil spring cj Calculation:

[0007] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the first end median diameter of each variable median diameter section is D j , j=1,2,…,n J , and the end diameter of the coil spring The number of effective turns of each segment n j , the horizontal plane projection length L of the wire diameter of each variable middle diameter section of the coil spring cj Calculate, that is

[0008]

[0009] S2: The rise angle α of each variable mid-diameter section of the multi-section variable mid-diameter combined coil spring j Calculation:

[0010] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the effective height H of each segment j0 , L calculated in step S1 cj , for each variable mid-diameter section of the coil spring, the rise angle α j Calculate, j = 1, 2, ..., n J ,Right now

[0011]

[0012] S3: Vertical flexibility R of multi-stage variable diameter combined coil spring dz Calculation:

[0013] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the first end median diameter of each variable median diameter section is D j , j=1,2,…,n J , the end diameter of the coil spring Poisson's ratio μ, shear modulus G, α calculated in step S2 j , the vertical flexibility R of the multi-stage variable mid-diameter combined coil spring dz Calculate, that is

[0014]

[0015] S4: Vertical stiffness K of multi-stage variable diameter combined coil spring z Calculation:

[0016] According to the R calculated in step S3 dz , the vertical stiffness K of the multi-stage variable diameter combined coil spring z Calculate, that is

[0017]

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention can calculate the vertical stiffness of the multi-section variable center diameter combined coil spring according to the structural parameters and material characteristic parameters of the multi-section variable center diameter combined coil spring. Through ANSYS simulation and experimental verification of the prototype, it can be known that the method can obtain an accurate and reliable calculation value of the vertical stiffness of the multi-section variable center diameter combined coil spring, ensure that the vertical stiffness of the multi-section variable center diameter combined coil spring meets the design requirements, improve the product design level and performance, improve the vehicle driving smoothness, and at the same time reduce the design and test costs and accelerate the product development speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart for calculating the vertical stiffness of a multi-stage variable mid-diameter combined helical spring;

[0021] Figure 2 It is a structural schematic diagram of a multi-stage variable middle diameter combined coil spring;

[0022] Figure 3 It is the structure and parameter symbol of the jth section of the multi-section variable center diameter combined coil spring. DETAILED DESCRIPTION

[0023] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0024] Example:

[0025] The calculation method of the vertical stiffness of the multi-stage variable center diameter combined coil spring of the present invention, the structural schematic diagram of the multi-stage variable center diameter combined coil spring, as shown in FIG. Figure 2 As shown, the number of segments of the multi-stage variable-mid-diameter combined coil spring is n J , the rise angle of each variable mid-diameter section The effective number of circles of each variable diameter section Effective height of each variable diameter section Among them, the sum of the effective turns of each variable mid-diameter section is equal to the effective turns n of the coil spring, that is, The sum of the effective heights of the variable mid-diameter sections is equal to the effective height H0 of the coil spring, that is, The median diameters of the first and second ends of each variable median diameter section are The end diameter of the coil spring The structure and parameter symbols of the jth variable mid-diameter section of the multi-section variable mid-diameter combined coil spring are as follows: Figure 3 As shown, the rise angle α of the jth variable mid-diameter segment j , the effective number of turns of the jth variable mid-diameter section n j , the effective height H of the jth variable mid-diameter section j0 , the first end median diameter of the jth median diameter section is D j , the end median diameter D of the jth median diameter change segment j+1 , j=1,2,…,n JThe coordinate system of the truncated cone type spiral spring is established with the center of the middle diameter of the spiral spring as the origin O, the starting point of the effective number of turns of the spring wire diameter from the origin O to the center of the middle diameter of the end as the Z axis. The elastic modulus E, Poisson's ratio μ, and shear modulus of the spiral spring material are

[0026] According to the structural parameters and material characteristic parameters of the multi-section variable center diameter combined coil spring, the vertical stiffness of the multi-section variable center diameter combined coil spring is calculated to ensure that the vertical stiffness of the multi-section variable center diameter combined coil spring meets the design requirements.

[0027] In order to meet the installation requirements, a certain suspension spring adopts a three-stage variable center diameter combined coil spring, that is, the number of sections with variable center diameter n J =3, where the middle diameter of the head end of each section is D1 = 100mm, D2 = 130mm, D3 = 130mm, and the middle diameter of the coil spring end is D4 = 105mm, the wire diameter is d = 13mm, where the effective number of turns n = 5, the effective number of turns of each section is n1 = 1.5, n2 = 2, n3 = 1.5; the effective height H0 = 330mm, where the effective height H0 of each section is 10 =90mm, H 20 =150mm, H 30 =90mm. Elastic modulus E = 206GPa, Poisson's ratio μ = 0.3, shear modulus According to the structural parameters and material characteristic parameters of the multi-section variable center diameter combined coil spring, the vertical stiffness of the multi-section variable center diameter combined coil spring is calculated.

[0028] The present invention provides a method for calculating the vertical stiffness of a multi-stage variable-mid-diameter combined helical spring, the calculation process of which is as follows: Figure 1 As shown, the specific calculation steps are as follows:

[0029] S1: Horizontal projection length L of each variable diameter section of the coil spring cj Calculation:

[0030] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J =3, the starting diameter of each variable diameter section of the coil spring is D1 = 100mm, D2 = 130mm, D3 = 130mm and the end diameter of the coil spring is D4 = 105mm, the effective number of turns of each section is n1 = 1.5, n2 = 2, n3 = 1.5, the length L of the projection of the wire diameter of each variable diameter section of the coil spring on the horizontal plane cj Calculate, j = 1, 2, ..., n J ,Right now

[0031]

[0032] Among them, the length L of the projection of the wire diameter of each variable mid-diameter section on the horizontal plane is calculated cj They are

[0033] L c1 =541.9mm, L c2 =816.8mm, L c3 =553.7mm;

[0034] S2: The rise angle α of each variable mid-diameter section of the multi-section variable mid-diameter combined coil spring j Calculation:

[0035] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J =3, the effective height of each section H 10 =90mm, H 20 =150mm, H 30 =90mm, L calculated in step S1 cj , that is, L c1 =541.9mm,L c2 =816.8mm,L c3 =553.7mm, the rise angle α of each variable mid-diameter section of the coil spring j Calculate, j = 1, 2, ..., n J ,Right now

[0036]

[0037] Among them, the calculated rise angle α of each variable mid-diameter section is j They are

[0038] α1=9.4293°, α2=10.4059°, α3=9.2322°;

[0039] S3: Vertical flexibility R of multi-stage variable diameter combined coil spring dz Calculation:

[0040] According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J =3, the starting diameters of the variable diameter sections of the coil spring are D1 = 100 mm, D2 = 130 mm, D3 = 130 mm, and the end diameter of the coil spring is D4 = 105 mm, Poisson's ratio μ = 0.3, shear modulus G = 79.231 GPa, and the α calculated in step S2 j , that is, α1 = 9.4293°, α2 = 10.4059°, α3 = 9.2322°, the vertical flexibility R of the multi-stage variable mid-diameter combined coil spring dz Calculate, that is

[0041]

[0042] S4: Vertical stiffness K of multi-stage variable diameter combined coil spring z Calculation:

[0043] According to the R calculated in step S3 dz =3.270×10 -2 mm / N, the vertical stiffness K of the multi-stage variable mid-diameter combined coil spring z Calculate, that is

[0044]

[0045] Through the ANSYS simulation and experimental test of the prototype, it can be known that the calculation method of the vertical stiffness of the multi-stage variable center diameter combined coil spring provided by the present invention is correct, and an accurate and reliable calculation value of the vertical stiffness of the multi-stage variable center diameter combined coil spring can be obtained, ensuring that the vertical stiffness of the multi-stage variable center diameter combined coil spring meets the design requirements, and lays a reliable technical foundation for the design of the multi-stage variable center diameter combined coil spring of the vehicle suspension and its key parameters. The method can improve the design level, product quality, reliability, service life, and vehicle driving smoothness and safety; at the same time, it can also reduce the design and testing costs of the product and speed up product development.

Claims

1. A method for calculating the vertical stiffness of a multi-stage variable mid-diameter combined helical spring, wherein: The coil spring is composed of a plurality of sections with variable mid-diameter sections. The vertical stiffness of the plurality of sections with variable mid-diameter combined coil spring is calculated according to the structural parameters and material characteristic parameters of the plurality of sections with variable mid-diameter combined coil spring. The calculation method is characterized in that the calculation method comprises the following steps: S1: Horizontal projection length L of each variable diameter section of the multi-section variable diameter combined coil spring cj Calculation: According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the first end median diameter of each variable median diameter section is D j , j=1,2,…,n J , and the end diameter of the coil spring The number of effective turns of each segment n j , the horizontal plane projection length L of the wire diameter of each variable middle diameter section of the coil spring cj Calculate, that is S2: The rise angle α of each variable mid-diameter section of the multi-section variable mid-diameter combined coil spring j Calculation: According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the effective height H of each segment j0 , L calculated in step S1 cj , for each variable mid-diameter section of the coil spring, the rise angle α j Calculate, j = 1, 2, ..., n J ,Right now S3: Vertical flexibility R of multi-stage variable diameter combined coil spring dz Calculation: According to the number of sections n of the variable diameter of the multi-section variable diameter combined coil spring J , the first end median diameter of each variable median diameter section is D j , j=1,2,…,n J , the end diameter of the coil spring Poisson's ratio μ, shear modulus G, α calculated in step S2 j , the vertical flexibility R of the multi-stage variable mid-diameter combined coil spring dz Calculate, that is S4: Vertical stiffness K of multi-stage variable diameter combined coil spring z Calculation: According to the R calculated in step S3 dz , the vertical stiffness K of the multi-stage variable diameter combined coil spring z Calculate, that is

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