CN105526290A - Method for designing gaps of end straight sections of diagonal few-leaf main springs and auxiliary springs - Google Patents

Abstract

The invention relates to a method for designing gaps of end straight sections of diagonal few-leaf main springs and auxiliary springs, and belongs to the technical field of suspension steel plate springs. The method includes determining endpoint deformation coefficients of the various main springs and deformation coefficients G<x-CD> of contact points of the end straight sections of the N<th> main springs and the auxiliary springs according to structure sizes and elastic modulus of the various diagonal variable-section main springs; acquiring endpoint force F<N> of the N<th> main springs according to acting load of the auxiliary springs and the endpoint deformation coefficients of the various main springs; designing the main and auxiliary spring gaps between contact points of the end straight sections of the main springs and the auxiliary springs according to the thicknesses h<2> of roots of the N<th> main springs, the endpoint force F<N> and the deformation coefficients G<x-CD>. The method has the advantages that as known from simulation verification, design values of the gaps of the end straight sections of the diagonal few-leaf variable-section main springs and the auxiliary springs can be accurately and reliably obtained by the aid of the method, and accordingly the product design level and performance and the vehicle ride comfort can be improved; the design and experiment costs can be reduced, and the product development speeds can be increased.

Description

The few main spring of sheet of bias type is in the design method in end flat segments and auxiliary spring gap

Technical field

The present invention relates to the design method of the few main spring of sheet of vehicle suspension leaf spring, particularly bias type in end flat segments and auxiliary spring gap.

Background technique

For few sheet variable-section steel sheet spring, in order to meet the requirement of variation rigidity, usually major and minor spring is designed to, and by major and minor spring gap, guarantee after being greater than certain load, major and minor spring contacts and cooperatively works, and meets vehicle suspension designing requirement to leaf spring rigidity in different loads situation.

Due to the 1st its stressed complexity of the main spring of few sheet variable cross section, not only bear vertical load, also bear torsional load and longitudinal loading simultaneously, therefore, the end thickness of the 1st leaf spring designed by reality, usual more each than other partially thicker, namely in actual design with in producing, mostly adopts the non-few sheet variable-section steel sheet spring waiting structure in end.At present less sheet variable-section steel sheet spring mainly contains two types, and one is parabolic shape, and another is bias type, and wherein, Parabolic stress is iso-stress, more reasonable than bias type of its stress loading.But, because the processing technology of parabolic shape variable cross section is complicated, need complexity, expensive process equipment, and the processing technology of bias type is simple, only need simple equipment just can process, therefore, meeting under stress intensity condition, the variable-section steel sheet spring of bias type can be adopted.For the major and minor spring of few sheet bias type variable cross section, because the length of auxiliary spring is different, auxiliary spring is not identical with the contact position of main spring yet, can be divided into and contact in end flat segments the major and minor leaf spring contacted with in oblique line section.Wait because end is non-the few sheet variable-section steel sheet spring of the bias type of structure to be out of shape calculating at an arbitrary position very complicated, therefore, fail to provide the design method of the few main spring of sheet of easy, accurate, reliable bias type in end flat segments and auxiliary spring gap so far always.

Although previously, once someone gave the design method of few sheet bias type variable-section steel sheet spring, such as, Peng Mo, high army is once in " automotive engineering ", (the 14th volume) the 3rd phase in 1992, give the design and calculation method of Varied section leaf spring, the method mainly designs for few sheet bias type variable-section steel sheet spring of the structures such as end, its deficiency to meet the non-designing requirement waiting few sheet bias type variable-section steel sheet spring of structure in end, the master of the main spring of few sheet bias type variable cross section at end flat segments and auxiliary spring point of contact place can not be met, the design in auxiliary spring gap.Use up possessor at present once to the non-distortion of the main spring of few sheet bias type variable cross section in end flat segments waiting structure in end, adopt ANSYS modeling and simulating method, but the method only can carry out simulating, verifying to the distortion of the variable-section steel sheet spring providing actual design structure, accurate analytical design method formula can not be provided, more can not meet fast-developing and that suspension leaf spring modernization CAD design software the is developed requirement of vehicle.

Therefore, must set up that a kind of the few main spring of sheet variable cross section of bias type is in the design method in end flat segments and auxiliary spring gap accurately, reliably, meet Vehicle Industry fast development and the requirement to suspension Precise Design for Laminated Spring, improve design level, the product quality and performances of few sheet variable-section steel sheet spring, improve vehicle run smoothness; Meanwhile, reduce design and testing expenses, accelerate product development speed.

Summary of the invention

For the defect existed in above-mentioned prior art, technical problem to be solved by this invention is to provide the design method of the few main spring of sheet of a kind of easy, reliable bias type in end flat segments and auxiliary spring gap, design flow diagram, as shown in Figure 1.The few sheet variable cross section major-minor spring of bias type is symplex structure, and the half symplex structure of spring can regard overhang as, and namely symmetrical center line regards the root fixed end of half spring as, and main spring end force bearing point and auxiliary spring contact see main spring end points and auxiliary spring end points respectively as.The half symplex structure schematic diagram of the few sheet variable cross section major-minor spring of bias type, as shown in Figure 2, wherein, comprising: main spring 1, root shim 2, auxiliary spring 3; End pad 4; The half length of each of main spring 1 is L, is be made up of root flat segments, oblique line section, end flat segments three sections, and the thickness of every sheet root flat segments is h ₂, the half of installing space is l ₃, the root of oblique line section is to the distance l of main spring end points ₂=L-l ₃; The end flat segments of each of main spring 1 is non-waits structure, and namely the thickness of the end flat segments of the 1st main spring and length, be greater than other thickness of each and length, and thickness and the length of the end flat segments of each are respectively h _1iand l _1i; The Thickness Ratio β of each oblique line section _i=h _1i/ h ₂, i=1,2 ..., N, N are the sheet number of main spring, and N is the integer of 2 ~ 4; Each root flat segments of main spring 1 and and the root flat segments of auxiliary spring 3 between be provided with root shim 2, end pad 4 is provided with between each end flat segments of main spring 1, the material of end pad is carbon fiber composite, in order to reduce frictional noise during spring works; The half length of auxiliary spring 3 is L _a, namely auxiliary spring end points is to the horizontal equivalent l of main spring end points ₀=L-L _a; Be provided with certain major and minor spring gap delta between the end flat segments of the main spring of N sheet and the ends points of auxiliary spring 3, when load be greater than auxiliary spring work load time, in auxiliary spring and main spring end flat segments, certain point contacts.Work load under stable condition at each chip architecture parameter of the main spring of bias type variable cross section, material characteristic parameter, auxiliary spring length, auxiliary spring, the few major-minor spring gap of the main spring of sheet variable cross section between end flat segments and auxiliary spring contact of bias type is designed.

For solving the problems of the technologies described above, the few main spring of sheet of bias type provided by the present invention, in the design method in end flat segments and auxiliary spring gap, is characterized in that adopting following design procedure:

(1) the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate:

According to the half length L of the main spring of few sheet bias type variable cross section, width b, elastic modulus E, the half l of installing space ₃, the root of oblique line section is to the distance l of main spring end points ₂=L-l ₃, the Thickness Ratio β of the oblique line section of i-th main spring _i, wherein, i=1,2 ..., N, N are main reed number, to the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate, namely

$G_{x-Di}=\frac{4}{Eb}(L^3-l_2^3)+\frac{6l_2^3{({\mathrm{\&beta;}}_i+1)}^2\&lsqb;3({\mathrm{\&beta;}}_i-1)-2{\mathrm{ln\&beta;}}_i(1+{\mathrm{\&beta;}}_i)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_i^3{l}_2^3}{Eb},i=1,2,...,N;$

The main spring of (2) N sheet bias type variable cross section is at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CDcalculate:

According to the half length L of the main spring of few sheet bias type variable cross section, width b, elastic modulus E, the root of oblique line section is to the distance l of main spring end points ₂, the Thickness Ratio β of the oblique line section of the main spring of N sheet _n, the horizontal equivalent l of auxiliary spring contact and main spring end points ₀, to the deformation coefficient G of the main spring of N sheet bias type variable cross section at end flat segments and auxiliary spring point of contact place _x-CDcalculate, namely

$\begin{array}{c}{G}_{x-CD}=\frac{4L^3+22l_2^3\left({\mathrm{\&beta;}}_N^3-1\right)+6l_2^3\&lsqb;3{\mathrm{\&beta;}}_N\left({\mathrm{\&beta;}}_N-1\right)-2\left(1+{\mathrm{\&beta;}}^3\right){\mathrm{ln\&beta;}}_N-6{\mathrm{\&beta;}}_N\left(1+{\mathrm{\&beta;}}_N\right){\mathrm{ln\&beta;}}_N\&rsqb;}{Eb}+\\ \frac{2\&lsqb;l_0^3+3{\mathrm{\&beta;}}_N^2\left(l_2^2{\mathrm{\&beta;}}_N^2-L^2{\mathrm{\&beta;}}_N-l_2^2\right)l_0\&rsqb;}{{\mathrm{Eb\&beta;}}_N^3};\end{array}$

(3) auxiliary spring works the end points power F of the main spring of N sheet bias type variable cross section under load _ncalculate:

I step: according to the thickness h of the root flat segments of the main spring of few sheet bias type variable cross section ₂, and the end points deformation coefficient G of each main spring of bias type variable cross section calculated in step (1) _x-Di, determine the half stiffness K of each main spring of bias type variable cross section _mi, namely

$K_{Mi}=\frac{h_2^3}{G_{x-Di}},i=1,2,...,N;$

II step: play the half of load and single-ended point load P according to required auxiliary spring, and the half stiffness K of the determined each main spring of bias type variable cross section in I step _mi, the end points power F of the main spring of N sheet bias type variable cross section under load that auxiliary spring is worked _ncalculate, namely

$F_N=\frac{K_{MN}P}{\underset{i=1}{\overset{N}{\&Sigma;}}{K}_{Mi}},i=1,2,...,N,$

In formula, K _mNbe the half rigidity of the main spring of N sheet bias type variable cross section;

(4) the major-minor spring gap delta of the main spring of bias type variable cross section between end flat segments and auxiliary spring contact designs:

According to the thickness h of the root flat segments of the main spring of bias type variable cross section ₂, the End Force F of the main spring of N sheet bias type variable cross section calculated in II step _n, and the main spring of N sheet calculated in step (2) is at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CD, the major-minor spring gap delta of the main spring of few sheet bias type variable cross section between end flat segments and auxiliary spring contact is designed, namely

$\mathrm{\&delta;}=G_{x-CD}\frac{F_N}{h_2^3}.$

The advantage that the present invention has than prior art

Wait because end is non-the few sheet variable-section steel sheet spring of the bias type of structure to be out of shape calculating at an arbitrary position very complicated, therefore, fail to provide the design method of the few main spring of sheet of easy, accurate, reliable bias type in end flat segments and auxiliary spring gap so far always.Although there is people once to adopt ANSYS modeling and simulating method to the non-few major and minor spring gap of sheet variable cross section of the bias type of structure of waiting, end at present, but the method only can carry out simulating, verifying to the distortion of the few sheet variable-section steel sheet spring providing actual design structure, accurate analytical design method formula can not be provided, more can not meet fast-developing and that suspension leaf spring modernization CAD design software the is developed requirement of vehicle.First the present invention according to physical dimension, the Young's modulus of the few main spring of sheet variable cross section of bias type, can determine the deformation coefficient of each main spring of bias type variable cross section at end points place, and the main spring of N is at the deformation coefficient at end flat segments and auxiliary spring point of contact place; Then, by the deformation coefficient of each main spring at end points place and Rigidity Calculation, the load that the main spring of N sheet bears at end points is obtained; Subsequently, according to the root thickness of the main spring of N sheet, the load that the main spring of N sheet bears at end points, and the deformation coefficient at end flat segments and auxiliary spring contacting points position place, design in the major and minor spring gap at end flat segments and auxiliary spring contacting points position place the few main spring of sheet variable cross section of bias type.By design example and ANSYS simulating, verifying known, the method can obtain accurately, reliably the few main spring of sheet of bias type is in the design load in end flat segments and auxiliary spring gap, for the major and minor spring gap of the few sheet variable-section steel sheet spring of bias type provides reliable design method, and establish reliable technical foundation for CAD software development.Utilize the method, improve design level, the product quality and performances of vehicle suspension variable-section steel sheet spring, reduce bearing spring quality and cost, improve conveying efficiency and the driving safety of vehicle; Meanwhile, also reduce design and testing expenses, accelerate product development speed.

Accompanying drawing explanation

In order to understand the present invention better, be described further below in conjunction with accompanying drawing.

Fig. 1 is the few main spring of sheet variable cross section of bias type in the design flow diagram in end flat segments and auxiliary spring gap;

Fig. 2 is the half symplex structure schematic diagram of the few sheet variable cross section major-minor spring of bias type;

Fig. 3 is the deformation simulation cloud atlas of the main spring of few sheet bias type variable-section steel sheet spring of embodiment one;

Fig. 4 is the deformation simulation cloud atlas of the main spring of few sheet bias type variable-section steel sheet spring of embodiment two.

Specific embodiments

Below by embodiment, the present invention is described in further detail.

Embodiment one: the sheet number N=2 of the main spring of certain few sheet bias type variable cross section, wherein, and the half length L=575mm of each main spring, width b=60mm, elastic modulus E=200GPa, the thickness h of root flat segments ₂=11mm, the half l of installing space ₃=55mm, the root of oblique line section is to the distance l of main spring end points ₂=L-l ₃=520mm; The thickness h of the end flat segments of the 1st main spring ₁₁=7mm, i.e. the Thickness Ratio β of the oblique line section of the 1st main spring ₁=h ₁₁/ h ₂the thickness h of the end flat segments of the=0.64,2nd main spring ₁₂=6mm, i.e. the Thickness Ratio β of the oblique line section of the 2nd main spring ₂=h ₁₂/ h ₂=0.55; The half length L of auxiliary spring _a=465mm, the horizontal equivalent l of auxiliary spring contact and main spring end points ₀=L-L _a=110mm, auxiliary spring contact contacts with certain point in the flat segments of main spring end.Auxiliary spring required by design works the half of load and single-ended point load P=1200N, designs the major-minor spring gap of the main spring of this few sheet bias type variable cross section between end flat segments and auxiliary spring contact.

The few main spring of sheet of the bias type that example of the present invention provides is in the design method in end flat segments and auxiliary spring gap, and as shown in Figure 1, concrete steps are as follows for its design cycle:

(1) the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate:

According to the half length L=575mm of the main spring of few sheet bias type variable cross section, width b=60mm, elastic modulus E=200GPa, the half l of installing space ₃=55mm, the root of oblique line section is to the distance l of main spring end points ₂=520mm, the Thickness Ratio β of the oblique line section of the 1st main spring ₁the Thickness Ratio β of the oblique line section of the=0.64,2nd main spring ₂=0.55, to the end points deformation coefficient G of the 1st, the 2nd main spring _x-D1, G _x-D2calculate respectively, namely

$G_{x-D1}=\frac{4}{Eb}\left(L^3-l_2^3\right)+\frac{6l_2^3{\left({\mathrm{\&beta;}}_1+1\right)}^2\&lsqb;3\left({\mathrm{\&beta;}}_1-1\right)-2{\mathrm{ln\&beta;}}_1\left(1+{\mathrm{\&beta;}}_1\right)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_1^3{l}_2^3}{Eb}=101.68{\mathrm{mm}}^4/N,$

$G_{x-D2}=\frac{4}{Eb}\left(L^3-l_2^3\right)+\frac{6l_2^3{\left({\mathrm{\&beta;}}_2+1\right)}^2\&lsqb;3\left({\mathrm{\&beta;}}_2-1\right)-2{\mathrm{ln\&beta;}}_2\left(1+{\mathrm{\&beta;}}_2\right)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_2^3{l}_2^3}{Eb}=109.72{\mathrm{mm}}^4/N;$

(2) the 2nd main springs of bias type variable cross section are at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CDcalculating:

According to the half length L=575mm of the main spring of few sheet bias type variable cross section, width b=60mm, elastic modulus E=200GPa, the root of oblique line section is to the distance l of main spring end points ₂=520mm, the Thickness Ratio β of the oblique line section of the 2nd main spring ₂=0.55, auxiliary spring contact is to the horizontal equivalent l of main spring end points ₀=110mm, to the deformation coefficient G of the 2nd main spring of bias type variable cross section at end flat segments and auxiliary spring point of contact place _x-CDcalculate, namely

$\begin{array}{c}{G}_{x-CD}=\frac{4L^3+22l_2^3\left({\mathrm{\&beta;}}_N^3-1\right)+6l_2^3\&lsqb;3{\mathrm{\&beta;}}_N\left({\mathrm{\&beta;}}_N-1\right)-2\left(1+{\mathrm{\&beta;}}^3\right){\mathrm{ln\&beta;}}_N-6{\mathrm{\&beta;}}_N\left(1+{\mathrm{\&beta;}}_N\right){\mathrm{ln\&beta;}}_N\&rsqb;}{Eb}+\\ \frac{2\&lsqb;l_0^3+3{\mathrm{\&beta;}}_N^2\left(l_2^2{\mathrm{\&beta;}}_N^2-L^2{\mathrm{\&beta;}}_N-l_2^2\right)l_0\&rsqb;}{{\mathrm{Eb\&beta;}}_N^3}=70.06{\mathrm{mm}}^4/N;\end{array}$

(3) auxiliary spring works the end points power F of the 2nd main spring of bias type variable cross section under load ₂calculate:

I step: according to the thickness h of the root flat segments of the main spring of few sheet bias type variable cross section ₂=11mm, and the G calculated in step (1) _x-D1=101.68mm ⁴/ N and G _x-D2=109.72mm ⁴/ N, determines the half stiffness K of the 1st, the 2nd main spring of bias type variable cross section _m1, K _m2, be respectively

$K_{M1}=\frac{h_2^3}{G_{x-D1}}=13.09N/mm,$

$K_{M2}=\frac{h_2^3}{G_{x-D2}}=12.13N/mm;$

II step: the auxiliary spring required by design works the half of load and single-ended point load P=1200N and determined K in I step _m1=13.09N/mm and K _m2=12.13N/mm, the end points power F of the 2nd main spring of bias type variable cross section under load that auxiliary spring is worked ₂calculate, namely

$F_2=\frac{K_{M2}P}{\underset{i=1}{\overset{2}{\&Sigma;}}{K}_{Mi}}=577.16N;$

(4) the major-minor spring gap delta of the main spring of bias type variable cross section between end flat segments and auxiliary spring contact designs:

According to the thickness h of the root flat segments of the main spring of bias type variable cross section ₂the end points power F of the 2nd main spring calculated in=11mm, II step ₂=577.16N, and the 2nd main spring calculated in step (2) is at the distortion number G at end flat segments and auxiliary spring point of contact place _x-CD=70.06mm ⁴/ N, designs the major-minor spring gap delta of the main spring of this bias type variable cross section between end flat segments and auxiliary spring contact, namely

$\mathrm{\&delta;}=G_{x-CD}\frac{F_2}{h_2^3}=30.38mm.$

Utilize ANSYS finite element emulation software, according to each chip architecture parameter and the material characteristic parameter of the main spring of this few sheet bias type variable cross section, set up the ANSYS simulation model of the half symplex structure of the main spring of this few sheet bias type variable cross section, grid division, and apply fixed constraint at the root of simulation model, concentrated load P=1200N is applied at end points, ANSYS emulation is carried out to the distortion of the main spring of this few sheet bias type variable-section steel sheet spring, the deformation simulation cloud atlas obtained, as shown in Figure 3, wherein, this main spring is at the amount of deformation δ=30.58mm at distance end position 110mm place.

Known, under same load, the ANSYS simulating, verifying value δ=30.58mm of the main spring amount of deformation of this leaf spring, match with major-minor spring gap design value δ=30.38mm, relative deviation is only 0.65%; Result shows that the few main spring of sheet of bias type that this invention provides is correct in the design method in end flat segments and auxiliary spring gap, and parameter designing value is accurately and reliably.

Embodiment two: the sheet number N=2 of the main spring of certain few sheet bias type variable cross section, wherein, and the half length L=600mm of each main spring, width b=60mm, elastic modulus E=200GPa, the thickness h of root flat segments ₂=14mm, the half l of installing space ₃=60mm, the root of oblique line section is to the distance l of main spring end points ₂=L-l ₃=540mm; The thickness h of the end flat segments of the 1st main spring ₁₁=9mm, i.e. the Thickness Ratio β of the oblique line section of the 1st main spring ₁=h ₁₁/ h ₂=0.64; The thickness h of the end flat segments of the 2nd main spring ₁₂=8mm, i.e. the Thickness Ratio β of the oblique line section of the 2nd main spring ₂=h ₁₂/ h ₂=0.57; The half length L of auxiliary spring _a=510mm, the horizontal equivalent l of auxiliary spring contact and main spring end points ₀=L-L _a=90mm, auxiliary spring contact contacts with certain point in the flat segments of main spring end.Auxiliary spring required by design works the half of load and single-ended point load P=3000N, designs the major-minor spring gap of the main spring of this few sheet bias type variable cross section between end flat segments and auxiliary spring contact.

Adopt the design method identical with embodiment one and step, design this main spring of few sheet bias type variable cross section gap between end flat segments and auxiliary spring contact, concrete steps are as follows:

(1) the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate:

According to the half length L=600mm of the main spring of few sheet bias type variable cross section, width b=60mm, elastic modulus E=200GPa, the half l of installing space ₃=60mm, the root of oblique line section is to the distance l of main spring end points ₂=540mm, the Thickness Ratio β of the oblique line section of the 1st main spring ₁the Thickness Ratio β of the oblique line section of the=0.64,2nd main spring ₂=0.57, to the 1st, the 2nd deformation coefficient G of main spring at endpoint location place _x-D1, G _x-D2calculate respectively, namely

$G_{x-D1}=\frac{4}{Eb}\left(L^3-l_2^3\right)+\frac{6l_2^3{\left({\mathrm{\&beta;}}_1+1\right)}^2\&lsqb;3\left({\mathrm{\&beta;}}_1-1\right)-2{\mathrm{ln\&beta;}}_1\left(1+{\mathrm{\&beta;}}_1\right)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_1^3{l}_2^3}{Eb}=114.27{\mathrm{mm}}^4/N,$

$G_{x-D2}=\frac{4}{Eb}\left(L^3-l_2^3\right)+\frac{6l_2^3{\left({\mathrm{\&beta;}}_2+1\right)}^2\&lsqb;3\left({\mathrm{\&beta;}}_2-1\right)-2{\mathrm{ln\&beta;}}_2\left(1+{\mathrm{\&beta;}}_2\right)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_2^3{l}_2^3}{Eb}=121.28{\mathrm{mm}}^4/N;$

(2) the 2nd main springs of bias type variable cross section are at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CDcalculate:

According to the half length L=600mm of the main spring of few sheet bias type variable cross section, width b=60mm, elastic modulus E=200GPa, the root of oblique line section is to the distance l of main spring end points ₂=540mm, the Thickness Ratio β of the oblique line section of the 2nd main spring ₂=0.57, the horizontal equivalent l of auxiliary spring contact and main spring end points ₀=90mm, to the deformation coefficient G of the 2nd main spring of bias type variable cross section at end flat segments and auxiliary spring point of contact place _x-CDcalculate, namely

$\begin{array}{c}{G}_{x-CD}=\frac{4L^3+22l_2^3\left({\mathrm{\&beta;}}_N^3-1\right)+6l_2^3\&lsqb;3{\mathrm{\&beta;}}_N\left({\mathrm{\&beta;}}_N-1\right)-2\left(1+{\mathrm{\&beta;}}^3\right){\mathrm{ln\&beta;}}_N-6{\mathrm{\&beta;}}_N\left(1+{\mathrm{\&beta;}}_N\right){\mathrm{ln\&beta;}}_N\&rsqb;}{Eb}+\\ \frac{2\&lsqb;l_0^3+3{\mathrm{\&beta;}}_N^2\left(l_2^2{\mathrm{\&beta;}}_N^2-L^2{\mathrm{\&beta;}}_N-l_2^2\right)l_0\&rsqb;}{{\mathrm{Eb\&beta;}}_N^3}=87.05{\mathrm{mm}}^4/N;\end{array}$

(3) auxiliary spring works the end points power F of the 2nd main spring of bias type variable cross section under load ₂calculate:

I step: according to the thickness h of the root flat segments of the main spring of few sheet bias type variable cross section ₂=14mm, and the G that in step (1), calculating gained arrives _x-D1=114.27mm ⁴/ N, G _x-D2=121.28mm ⁴/ N, determines the half stiffness K of the 1st, the 2nd main spring _m1, K _m2, be respectively

$K_{M1}=\frac{h_2^3}{G_{x-D1}}=24.01N/mm,$

$K_{M2}=\frac{h_2^3}{G_{x-D2}}=22.63N/mm;$

II step: to work the half of load and single-ended point load P=3000N and determined K in I step according to auxiliary spring _m1=24.01N/mm and K _m2=22.63N/mm, the end points power F of the 2nd main spring of bias type variable cross section under load that auxiliary spring is worked ₂calculate, namely

$F_2=\frac{K_{M2}P}{\underset{i=1}{\overset{2}{\&Sigma;}}{K}_{Mi}}=1455.60N;$

(4) the major-minor spring gap delta of the main spring of bias type variable cross section between end flat segments and auxiliary spring contact designs:

According to the thickness h of the root flat segments of the main spring of bias type variable cross section ₂the end points power F of the 2nd main spring calculated in=14mm, II step ₂=1455.60N, and the G that in step (2), calculating gained arrives _x-CD=87.05mm ⁴/ N, designs the major and minor spring gap delta of the main spring of few sheet bias type variable cross section between end flat segments and auxiliary spring contact, namely

$\mathrm{\&delta;}=G_{x-CD}\frac{F_2}{h_2^3}=46.18mm.$

Utilize ANSYS finite element emulation software, according to each chip architecture parameter and the material characteristic parameter of the main spring of this few sheet bias type variable cross section, set up the ANSYS simulation model of the half symplex structure of the main spring of this few sheet bias type variable cross section, grid division, and apply fixed constraint at the root of simulation model, concentrated load P=3000N is applied at end points, ANSYS emulation is carried out to the distortion of the main spring of this few sheet bias type variable-section steel sheet spring, the deformation simulation cloud atlas obtained, as shown in Figure 4, wherein, this main spring is at the amount of deformation δ=46.31mm at distance end position 90mm place.

Known, under same load, the ANSYS simulating, verifying value δ=46.31mm of the main spring amount of deformation of this leaf spring, match with major-minor spring gap design value δ=46.18mm, relative deviation is only 0.28%; Result shows that the few main spring of sheet of bias type that this invention provides is correct in the design method in end flat segments and auxiliary spring gap, and parameter designing value is accurately and reliably.

Claims (1)

1. the few main spring of sheet of bias type is in the design method in end flat segments and auxiliary spring gap, wherein, the variable cross section of main spring is bias type, the half symplex structure of the few main spring of sheet of bias type is made up of root flat segments, oblique line section and end flat segments three sections, and structure such as the end flat segments of each main spring non-grade, namely the thickness of the end flat segments of the 1st main reed and length, be greater than other thickness of each and length; Be provided with certain major-minor spring gap delta between the end flat segments of auxiliary spring contact and the main spring of N sheet, work the designing requirement of load to meet auxiliary spring; Work load under stable condition at each chip architecture parameter of main spring, material characteristic parameter, auxiliary spring length, auxiliary spring, the few major-minor spring gap of the main spring of sheet variable cross section between end flat segments and auxiliary spring contact of bias type designed, specific design step:

(1) the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate:

According to the half length L of the main spring of few sheet bias type variable cross section, width b, elastic modulus E, the half l of installing space ₃, the root of oblique line section is to the distance l of main spring end points ₂=L-l ₃, the Thickness Ratio β of the oblique line section of i-th main spring _i, wherein, i=1,2 ..., N, N are main reed number, to the end points deformation coefficient G of each main spring of bias type variable cross section _x-Dicalculate, namely

$G_{x-Di}=\frac{4}{Eb}\left(L^3-l_2^3\right)+\frac{6l_2^3{\left({\mathrm{\&beta;}}_i+1\right)}^2\&lsqb;3\left({\mathrm{\&beta;}}_i-1\right)-2{\mathrm{ln\&beta;}}_i\left(1+{\mathrm{\&beta;}}_i\right)\&rsqb;}{Eb}+\frac{4{\mathrm{\&beta;}}_i^3{l}_2^3}{Eb},i=1,2,\mathrm{...},N;$

The main spring of (2) N sheet bias type variable cross section is at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CDcalculate:

According to the half length L of the main spring of few sheet bias type variable cross section, width b, elastic modulus E, the root of oblique line section is to the distance l of main spring end points ₂, the Thickness Ratio β of the oblique line section of the main spring of N sheet _n, the horizontal equivalent l of auxiliary spring contact and main spring end points ₀, to the deformation coefficient G of the main spring of N sheet bias type variable cross section at end flat segments and auxiliary spring point of contact place _x-CDcalculate, namely

$\begin{array}{c}{G}_{x-CD}=\frac{4L^3+22l_2^3\left({\mathrm{\&beta;}}_N^3-1\right)+6l_2^3\&lsqb;3{\mathrm{\&beta;}}_N\left({\mathrm{\&beta;}}_N-1\right)-2\left(1+{\mathrm{\&beta;}}^3\right){\mathrm{ln\&beta;}}_N-6{\mathrm{\&beta;}}_N\left(1+{\mathrm{\&beta;}}_N\right){\mathrm{ln\&beta;}}_N\&rsqb;}{Eb}+\\ \frac{2\&lsqb;l_0^3+3{\mathrm{\&beta;}}_N^2\left(l_2^2{\mathrm{\&beta;}}_N^2-L^2{\mathrm{\&beta;}}_N-l_2^2\right)l_0\&rsqb;}{{\mathrm{Eb\&beta;}}_N^3};\end{array}$

(3) auxiliary spring works the end points power F of the main spring of N sheet bias type variable cross section under load _ncalculate:

I step: according to the thickness h of the root flat segments of the main spring of few sheet bias type variable cross section ₂, and the end points deformation coefficient G of each main spring of bias type variable cross section calculated in step (1) _x-Di, determine the half stiffness K of each main spring of bias type variable cross section _mi, namely

$K_{Mi}=\frac{h_2^3}{G_{x-Di}},i=1,2,...,N;$

II step: play the half of load and single-ended point load P according to required auxiliary spring, and the half stiffness K of the determined each main spring of bias type variable cross section in I step _mi, the end points power F of the main spring of N sheet bias type variable cross section under load that auxiliary spring is worked _ncalculate, namely

$F_N=\frac{K_{MN}P}{\underset{i=1}{\overset{N}{\&Sigma;}}{K}_{Mi}},i=1,2,\mathrm{...},N,$

In formula, K _mNbe the half rigidity of the main spring of N sheet bias type variable cross section;

(4) the major-minor spring gap delta of the main spring of bias type variable cross section between end flat segments and auxiliary spring contact designs:

According to the thickness h of the root flat segments of the main spring of bias type variable cross section ₂, the End Force F of the main spring of N sheet bias type variable cross section calculated in II step _n, and the main spring of N sheet calculated in step (2) is at the deformation coefficient G at end flat segments and auxiliary spring point of contact place _x-CD, the major-minor spring gap delta of the main spring of few sheet bias type variable cross section between end flat segments and auxiliary spring contact is designed, namely

$\mathrm{\&delta;}=G_{x-CD}\frac{F_N}{h_2^3}.$