CN106383966A - Design method for limiting deflection of few-leaf parabolic steel plate spring with non-isotactic end parts - Google Patents

Abstract

The invention relates to a design method for limiting deflection of a few-leaf parabolic steel plate spring with non-isotactic end parts, and belongs to the technical field of suspension steel plate springs. The limiting deflection of the few-leaf parabolic steel plate spring with the non-isotactic end parts can be designed according to structural parameters, elastic moduli and maximum allowable safety stresses of spring leaves and free length of a limiting block. Through loading deformation experimental testing of a model machine, it is known that the design method for the limiting deflection of the few-leaf parabolic steel plate spring with the non-isotactic end parts, provided by the invention, is correct; an accurate and reliable limiting deflection design value can be obtained; and a reliable technical foundation is laid for design of the few-leaf parabolic steel plate spring with the non-isotactic end parts, and CAD software development. By utilizing the method, the product design level, quality and performance and the vehicle driving smoothness can be improved, the product design and experimental testing expenses are reduced, and the product development speed is increased.

Description

The non-method for designing waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in end

Technical field

The present invention relates to vehicle suspension leaf spring, particularly end non-grade structure lacks, and piece parabolic type leaf spring is spacing to scratch The method for designing of degree.

Background technology

With vehicle energy saving, comfortableization, lightweight, safe fast development, few piece variable-section steel sheet spring is because of tool Have lightweight, stock utilization is high, no rub between piece or friction is little, vibration noise is low, the advantages of long service life, be increasingly subject to The highest attention of vehicle suspension expert, manufacturing enterprise and vehicle manufacture enterprise, and obtained in vehicle suspension system extensively Application.Generally for the design requirement meeting processing technology, stress intensity, rigidity and hanger thickness, piece Variable Section Steel can will be lacked The different structure form such as flat spring is processed as that parabolic type, bias type, root be reinforced, reinforcement end, two ends are reinforced, this Outward, because the stress of few piece variable-section steel sheet spring the 1st flat spring is complex, be subjected to vertical load, simultaneously also subject to Torsional load and longitudinal loading, therefore, reality designed by the thickness of end flat segments of the 1st flat spring and length, more than it The thickness of his each flat spring end flat segments and length, mostly adopt the non-few piece variable-section steel sheet spring waiting structure in end, with Meet the complicated requirement of the 1st flat spring stress.Understood according to consulting reference materials, do not provided reliable end inside and outside predecessor State always non- Method for designing Deng the few spacing amount of deflection of piece parabolic type leaf spring of structure.With Vehicle Speed and its to ride comfort requirement Improve constantly, the few piece parabolic type leaf spring that wait structure non-to end is put forward higher requirement, therefore, it is necessary to set up a kind of The method for designing of the few spacing amount of deflection of piece parabolic type leaf spring of structure such as accurately, reliable end is non-, being that end is non-waits lacking of structure Reliable technical foundation is established in the spacing amount of deflection design of piece parabolic type leaf spring, meets Vehicle Industry fast development, vehicle Ride performance and the design requirement of few piece parabolic type leaf spring of structure such as end is non-, improve product design level, quality And performance, meet the design requirement of vehicle ride performance；Meanwhile, reduce design and testing expenses, accelerate product development speed.

Content of the invention

For defect present in above-mentioned prior art, the technical problem to be solved be provide a kind of easy, The non-method for designing waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in reliable end, its design flow diagram, as Fig. 1 institute Show.The half symmetrical structure of few piece parabolic type variable-section steel sheet spring can see Cantilever Beams of Variable Cross Section as, will symmetrical centre The root fixing end of half spring seen as by line, and spring end stress point is seen as spring end points.The non-few piece waiting structure in end The half symmetrical structure schematic diagram of parabolic type variable-section steel sheet spring, as shown in Fig. 2 including, spring 1, root shim 2, end pad 3.The half length of each of spring 1 is L_M, it is by root flat segments, parabolic segment and three sections of institutes of end flat segments Constitute, the thickness of the root flat segments of every flat spring is h_2M, the half of installing space is l₃, the width of each flat spring is b；Spring The end flat segments of 1 each are non-to wait structure, i.e. the thickness of end flat segments of the 1st flat spring and length, more than other thickness of each Degree and length, the thickness of end flat segments of each flat spring and length are respectively h_1MiAnd l_1Mi, i=1,2 ..., N, N are spring leaf Number；Middle variable cross-section is parabolic segment, and the thickness of each parabolic segment ratio is for β_i=h_1Mi/h_2M, the root of parabolic segment is to spring The distance of end points is l_2M=L_M-l₃, the end of parabolic segment is to spring end points apart from l_1Mi=l_2Mβ_i ².The root that spring 1 is each It is provided with root shim 2 between flat segments, between the end flat segments of each of spring 1, be provided with end pad 3, the material of end pad For carbon fibre composite, to reduce frictional noise produced by spring works.Structural parameters, springform in each flat spring In the case of amount, maximum allowable safe stress and limited block drift give, the few piece parabolic type steel plate that wait structure non-to end The spacing amount of deflection of spring is designed.

For solving above-mentioned technical problem, end provided by the present invention is non-to wait structure few piece parabolic type leaf spring is spacing scratches The method for designing of degree is it is characterised in that adopt following design procedure：

(1) the parabolic type leaf spring head flat spring end points deformation coefficient G under end points stressing conditions_x-D1Calculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M, width b, half l of installing space₃, parabolic Line root is to spring end points apart from l_2M, elastic modulus E, the thickness of the parabolic segment of the 1st flat spring compares β₁, to end points stress feelings Deformation coefficient G at end points for the first flat spring under condition_x-D1Calculated, that is,

$G_{x-D1}=\frac{4\[l_{2M}^3(1-{\mathrm{\β}}_1^3)+{(L_M-l_3/2)}^3\]}{Eb};$

(2) parabolic type leaf spring head flat spring half stiffness K in the clamp state_M1Calculating：

Root thickness h according to few piece parabolic type variable-section steel sheet spring_2M, and calculated G in step (1)_x-D1, Determine first flat spring half stiffness K in the clamp state_M1, that is,

$K_{M1}=\frac{h_{2M}^3}{G_{x-D1}};$

(3) based on half maximum load F suffered by the first flat spring of maximum allowable safe stress_maxCalculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M, width b, half l of installing space₃, root Thickness h_2M, and maximum allowable safe stress [σ], determine maximum based on the half suffered by the first flat spring of maximum allowable safe stress Load F_max, that is,

$F_{\max }=\frac{{\mathrm{bh}}_{2M}^2\[\mathrm{\σ}\]}{6(L_M-L_3/2)};$

(4) non-spacing amount of deflection h of few piece parabolic type leaf spring waiting structure in end_xwDesign：

I step：According to calculated K in step (2)_M1, and F determined by step (3)_max, under maximum load The Leading Edge Deformation f of leaf spring_mCalculated, that is,

$f_m=\frac{F_{\max }}{K_{M1}};$

II step：Drift L according to limited block_xw, and calculated f in I step_m, determine end non-grade structure The spacing amount of deflection of few piece parabolic type leaf spring, that is,

$h_{xw}=f_m-\frac{4}{3}{L}_{xw}.$

The present invention has the advantage that than prior art

The few spacing amount of deflection of piece parabolic type leaf spring of reliable end non-grade structure be not given always inside and outside predecessor State Method for designing.The present invention can according to the structural parameters of each flat spring, elastic modelling quantity, maximum allowable safe stress and limited block freely Length, the spacing amount of deflection of the few piece parabolic type leaf spring that wait structure non-to end is designed.Tried by model machine load deflection Test examination understands, the non-method for designing waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in end provided by the present invention is just True, can get accurately and reliably spacing amount of deflection design load, be the design of the non-few piece parabolic type leaf spring waiting structure in end And CAD software exploitation established reliable technical foundation；Meanwhile, using the method, product design level, product quality can be improved With vehicle ride performance；Meanwhile, also can reduce design and experimental test expense, accelerate product development speed.

Brief description

For a better understanding of the present invention, it is described further below in conjunction with the accompanying drawings.

Fig. 1 is the non-design flow diagram waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in end；

Fig. 2 is the structural representation of the non-half waiting the few piece parabolic type variable-section steel sheet spring of structure in end.

Specific embodiments

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

Embodiment one：Half length L of each flat spring of certain few piece parabolic type variable-section steel sheet spring_M=575mm, width B=60mm, the thickness h of root flat segments_2M=11mm, half l of installing space₃=55mm, the root of parabolic segment is to spring End points apart from l_2M=L_M-l₃=520mm, elastic modulus E=200GPa；The thickness h of the end flat segments of the 1st flat spring_1M1= 7mm, the thickness of parabolic segment compares β₁=h_1M1/h_2M=0.64, drift L of limited block_xw=15mm.The maximum of this spring is permitted With safe stress [σ]=900MPa, the spacing amount of deflection of the few piece parabolic type leaf spring that wait structure non-to this end is designed.

The non-method for designing waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in end that present example is provided, its Design cycle is as shown in figure 1, comprise the following steps that：

(1) the parabolic type leaf spring head flat spring end points deformation coefficient G under end points stressing conditions_x-D1Calculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M=575mm, width b=60mm, clipping room Away from half l₃=55mm, parabola root is to spring end points apart from l_2M=520mm, elastic modulus E=200GPa, the 1st The thickness of the parabolic segment of spring compares β₁=0.64, to deformation coefficient at end points for the first flat spring under end points stressing conditions G_x-D1Calculated, that is,

$G_{x-D1}=\frac{4\[l_{2M}^3(1-{\mathrm{\β}}_1^3)+{(L_M-l_3/2)}^3\]}{Eb}=89.29{\mathrm{mm}}^4/N;$

(2) parabolic type leaf spring head flat spring half stiffness K in the clamp state_M1Calculating：

Root thickness h according to few piece parabolic type variable-section steel sheet spring_2MIt is calculated in=11mm, and step (1) G_x-D1=89.29mm⁴/ N, determines first flat spring half stiffness K in the clamp state_M1, that is,

$K_{M1}=\frac{h_{2M}^3}{G_{x-D1}}=14.91N/mm;$

(3) based on half maximum load F suffered by the first flat spring of maximum allowable safe stress_maxCalculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M=575mm, width b=60mm, clipping room Away from half l₃=55mm, root thickness h_2M=11mm, and maximum allowable safe stress [σ]=900MPa, determine based on maximum Half maximum load F suffered by first flat spring of safe stress allowable_max, that is,

$F_{max}=\frac{{\mathrm{bh}}_{2M}^2\[\mathrm{\σ}\]}{6(L_M-L_3/2)}=1989N;$

(4) non-spacing amount of deflection h of few piece parabolic type leaf spring waiting structure in end_xwDesign：

I step：According to calculated K in step (2)_M1F determined by in=14.91N/mm, and step (3)_max= 1989N, the Leading Edge Deformation f to the leaf spring under maximum load_mCalculated, that is,

$f_m=\frac{F_{max}}{K_{M1}}=133.40mm;$

II step：Drift L according to limited block_xwCalculated f in=15mm, and I step_m=133.40mm, Determine the spacing amount of deflection of the non-few piece parabolic type leaf spring waiting structure in end, that is,

$h_{xw}=f_m-\frac{4}{3}{L}_{xw}=113.40mm.$

Tested by prototype test, the spacing amount of deflection design load of spring is reliable, end non-grade structure can be met Lack the design requirement of the spacing amount of deflection of piece parabolic type leaf spring, result shows that the few piece of end non-grade structure that this invention is provided is thrown The method for designing of the spacing amount of deflection of thing line style leaf spring is correct, and parameter designing value is accurately and reliably.

Embodiment two：Half length L of each flat spring of certain few piece parabolic type variable-section steel sheet spring_M=600mm, width B=60mm, the thickness h of root flat segments_2M=12mm, half l of installing space₃=60mm, the root of parabolic segment is to spring End points apart from l_2M=L_M-l₃=540mm, elastic modulus E=200GPa；The thickness h of the end flat segments of the 1st flat spring_1M1= 8mm, the thickness of parabolic segment compares β₁=h_1M1/h_2M=0.67, drift L of limited block_xw=12mm.The maximum of this spring is permitted With safe stress [σ]=900MPa, the spacing amount of deflection of the few piece parabolic type leaf spring that wait structure non-to this end is designed.

Using with embodiment one identical method for designing and step, the limit to this few piece parabolic type variable-section steel sheet spring Position amount of deflection is designed, and comprises the following steps that：

(1) the parabolic type leaf spring head flat spring end points deformation coefficient G under end points stressing conditions_x-D1Calculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M=600mm, width b=60mm, clipping room Away from half l₃=60mm, parabola root is to spring end points apart from l_2M=540mm, E=200GPa, the throwing of the 1st flat spring The thickness of thing line segment compares β₁=0.67, to deformation coefficient G at end points for the first flat spring under end points stressing conditions_x-D1Counted Calculate, that is,

$G_{x-D1}=\frac{4\[l_{2M}^3(1-{\mathrm{\β}}_1^3)+{(L_M-l_3/2)}^3\]}{Eb}=98.43{\mathrm{mm}}^4/N;$

(2) parabolic type leaf spring head flat spring half stiffness K in the clamp state_M1Calculating：

Root thickness h according to few piece parabolic type variable-section steel sheet spring_2MIt is calculated in=12mm, and step (1) G_x-D1=98.43mm⁴/ N, determines first flat spring half stiffness K in the clamp state_M1, that is,

$K_{M1}=\frac{h_{2M}^3}{G_{x-D1}}=17.56N/mm;$

(3) based on half maximum load F suffered by the first flat spring of maximum allowable safe stress_maxCalculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M=600mm, width b=60mm, clipping room Away from half l₃=60mm, root thickness h_2M=12mm, and maximum allowable safe stress [σ]=900MPa, determine based on maximum Half maximum load F suffered by first flat spring of safe stress allowable_max, that is,

$F_{max}=\frac{{\mathrm{bh}}_{2M}^2\[\mathrm{\σ}\]}{6(L_M-L_3/2)}=2273.70N;$

(4) non-spacing amount of deflection h of few piece parabolic type leaf spring waiting structure in end_xwDesign：

I step：According to calculated K in step (2)_M1F determined by in=17.56N/mm, and step (3)_max= 2273.70N, the Leading Edge Deformation f to the leaf spring under maximum load_mCalculated, that is,

$f_m=\frac{F_{max}}{K_{M1}}=129.48mm;$

II step：Drift L according to limited block_xwCalculated f in=12mm, and I step_m=129.48mm, Determine the spacing amount of deflection of the non-few piece parabolic type leaf spring waiting structure in end, that is,

$h_{xw}=f_m-\frac{4}{3}{L}_{xw}=113.48mm.$

Tested by prototype test, the spacing amount of deflection design load of spring is reliable, end non-grade structure can be met Lack the design requirement of the spacing amount of deflection of piece parabolic type leaf spring, result shows that the few piece of end non-grade structure that this invention is provided is thrown The method for designing of the spacing amount of deflection of thing line style leaf spring is correct, and parameter designing value is accurately and reliably.

Claims (1)

1. the non-method for designing waiting the few spacing amount of deflection of piece parabolic type leaf spring of structure in end, wherein, the non-few piece waiting structure in end The end non-grade structure of each flat spring of parabolic type variable-section steel sheet spring, i.e. the thickness of the 1st flat spring end flat segments and length, More than other each thickness and length；In the structural parameters of each flat spring, elastic modelling quantity, maximum allowable safe stress and spacing In the case of block drift gives, the spacing amount of deflection of the few piece parabolic type leaf spring that wait structure non-to end is designed, tool Body design procedure is as follows：

(1) the parabolic type leaf spring head flat spring end points deformation coefficient G under end points stressing conditions_x-D1Calculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M, width b, half l of installing space₃, parabola root Portion is to spring end points apart from l_2M, elastic modulus E, the thickness of the parabolic segment of the 1st flat spring compares β₁, under end points stressing conditions Deformation coefficient G at end points for the first flat spring_x-D1Calculated, that is,

$G_{x-D1}=\frac{4\[l_{2M}^3(1-{\mathrm{\β}}_1^3)+{(L_M-l_3/2)}^3\]}{Eb};$

(2) parabolic type leaf spring head flat spring half stiffness K in the clamp state_M1Calculating：

Root thickness h according to few piece parabolic type variable-section steel sheet spring_2M, and calculated G in step (1)_x-D1, determine First flat spring half stiffness K in the clamp state_M1, that is,

$K_{M1}=\frac{h_{2M}^3}{G_{x-D1}};$

(3) based on half maximum load F suffered by the first flat spring of maximum allowable safe stress_maxCalculating：

Half length L according to few piece parabolic type variable-section steel sheet spring_M, width b, half l of installing space₃, root thickness h_2M, and maximum allowable safe stress [σ], determine based on the half maximum load suffered by the first flat spring of maximum allowable safe stress F_max, that is,

$F_{max}=\frac{{\mathrm{bh}}_{2M}^2\[\mathrm{\σ}\]}{6(L_M-L_3/2)};$

(4) non-spacing amount of deflection h of few piece parabolic type leaf spring waiting structure in end_xwDesign：

I step：According to calculated K in step (2)_M1, and F determined by step (3)_max, to the steel plate under maximum load The Leading Edge Deformation f of spring_mCalculated, that is,

$f_m=\frac{F_{\max }}{K_{M1}};$

II step：Drift L according to limited block_xw, and calculated f in I step_m, determine the non-few piece waiting structure in end The spacing amount of deflection of parabolic type leaf spring, that is,

$h_{xw}=f_m-\frac{4}{3}{L}_{xw}.$