CN104899444A - Determination method for structural parameter of moment limiter of bent board matched with tower crane - Google Patents

Abstract

The invention discloses a determination method for a structural parameter of a moment limiter of a bent board matched with a tower crane and relates to a moment limiter of a tower crane for displaying the load moment in real time so as to pre-warn overload. The determination method particularly aims at a double-hanging-point upper rotary tower crane. The determination method aims at solving the problem that the precision is not high and the sensitivity is relatively low due to insufficient deflection variation because of ubiquitous insufficiency of magnifying power of the existing moment limiter of the bent board. The determination method is used for deducing specific analysis formulae of the magnifying power and the deflection by virtue of a mechanics analysis method and an analytical method, and a mathematical model that the moment limiter of the bent board is matched with the tower crane is established, so that the tower crane is matched with the structural parameter of the moment limiter of the bent board. The determination method disclosed by the invention has theoretical and application values in designing the moment limiter of the bent board and improving the sensitivity. After the model number of the tower crane is determined and the moment limiter of the bent board is initially selected, whether the magnifying power and the deflection meet the using demand or not is calculated by the determination method, so that the structural parameter of the moment limiter of the bent board is optimized and matched.

Description

A kind of bow plate limiter of moment structural parameter determining method mated with tower machine

Technical field

The present invention relates to a kind of bow plate limiter of moment structural parameter determining method mated with tower machine, it relate to a kind of for showing hoisting moment in real time to overload the tower machine limiter of moment that gives warning in advance, especially for two suspension centre top slewing tower machine.

Background technology

Along with the quickening of Chinese Urbanization construction process, the recoverable amount of tower machine continues soaring.Meanwhile, the incidence of tower machine great bodily injury accident also remained high, and tower machine accident rate was increased to 22.7 ‰ in 2011 from 1999 3.9 ‰, and overload is the main cause causing tower machine accident.Limiter of moment is also the most effective safety guard as the most important of tower machine indispensability, is widely used in the accident of falling tower preventing tower machine from causing because of overload.

Limiter of moment is generally divided into mechanical type and electronic type, and mechanical type comprises eccentric links formula and bow is board-like, and owing to bending, board-like limiter of moment structure is simple, cost is low, easy to maintenance, is therefore adopted by most limiter of moment.But the problem that existing bow board-like limiter of moment ubiquity precision is not high, sensitivity is on the low side, this is not mainly caused by bow plate limiter of moment magnification and fleximeter are calculated accurately really.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of bow plate limiter of moment structural parameter determining method mated with tower machine, improves precision and the sensitivity of bow plate limiter of moment.

For solving the problems of the technologies described above, the technical solution adopted in the present invention is: a kind of bow plate limiter of moment structural parameter determining method mated with tower machine, and parameter determination method of the present invention is carried out according to the following steps:

The first step, calculates magnification analytic expression as follows:

A, the calculating bow plate deflection on bow plate limiter of moment axis of symmetry.First bow plate moment is limited it and carry out force analysis, get any differential of the arc section on cambered plate and calculate it and bend the deflection on plate limiter of moment axis of symmetry, higher order indefinite small is ignored by after power series expansion, then in whole length range, integration is carried out, obtain bending the deflection of plate on bow plate limiter of moment axis of symmetry

$\mathrm{\Δ}=\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(1\right)$

In above-mentioned formula (1), Δ is that bow plate is bending deflection total on plate limiter of moment axis of symmetry direction, and bow when a' is the limiter of moment work of bow plate is high, L " ₀for bending the length after plate occurs bending and deformation when tower machine works;

B, the maximum deformation quantity of calculating bow plate limiter of moment under pressure F effect.The deflection of bow plate on bow plate limiter of moment axis of symmetry is caused by two parts, Part I be due to pressure F cause tower owner chord member be out of shape cause at axis of symmetry axial support displacement amount Δ 1, Part II is self bending deformation quantity Δ 2 after bow plate inital bending

$\mathrm{\Δ}1=\frac{F{L}_0^{\′\′}}{\mathrm{EA}}---\left(2\right)$

$\mathrm{\Δ}2=\frac{{\mathrm{\π}}^2{a}^2}{L_0}---\left(3\right)$

Δ＝Δ1+Δ2 (4)

In above-mentioned formula (2), (3), (4), in formula Δ 1 for pressure F cause tower owner chord member be out of shape cause in the axial support displacement amount of symmetry, Δ 2 is the bending deformation quantity in x-axis direction after bow plate inital bending when tower machine works, F is main chord axle pressure, L' ₀for bow plate when bow plate is welded on tower owner chord member tentatively bending after length, E is the elastic modulus of tower owner chord member, and a is that bow plate is in the half perpendicular to maximum deformation quantity on axis of symmetry direction when not working for tower machine, and A is tower owner chord member sectional area;

C, calculating bow plate limiter of moment magnification analytic expression.Bow plate limiter of moment magnification is defined as bow High variation amount and the ratio of length of bow's variable quantity, bends length of bow L when plate limiter of moment works according to above-mentioned analysis " ₀expression formula and magnification analytic expression as follows,

$L_0^{\′\′}=L_0-\mathrm{\Δ}=L_0-\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(5\right)$

$k=\frac{\mathrm{\Δ}{a}^{\′}}{\mathrm{\Δ}{L}_0^{\′\′}}=\frac{\∂a^{\′}}{\∂L_0^{\′\′}}=\frac{L_0^2(F+\mathrm{EA})+2{\mathrm{\π}}^2{a}^2\mathrm{EA}}{2\mathrm{\π}\sqrt{\mathrm{EA}(L_0^2-{\mathrm{\π}}^2{a}^2)(L_0^{2}F+{\mathrm{\π}}^2{a}^2\mathrm{EA})}}---\left(6\right)$

Second step, calculates bow plate limiter of moment amount of deflection analytic expression in accordance with the following steps.Bow plate limiter of moment generally has three kinds of models: rectilinearity, circular arc and sinusoidal pattern, in view of sinusoidal pattern application is more, therefore the present invention calculates amount of deflection analytic expression for sinusoidal pattern bow plate limiter of moment, and all the other two profiles number can adopt same procedure to calculate.

A, calculating deflection curve equation.On sinusoidal pattern bow plate limiter of moment, any point amount of deflection ω meets deflection curve equation:

$\mathrm{\ω}=a^{\′}[1-\cos \left(\frac{2\mathrm{\πx}}{L_0^{\′\′}}\right)]---\left(7\right)$

In above-mentioned formula (7), x bends plate limiter of moment bottom for the displacement of any point on axis of symmetry direction on true origin bow plate.

Bring publicity (7) into according to the result of calculation of formula (1), (2), (3), (4), and consider that the distortion of tower owner chord member is less, can simplify line of deflection is expressed to result of calculation,

$\mathrm{\ω}=\sqrt{a^2+\frac{F{L}_0^2}{{\mathrm{\π}}^2\mathrm{EA}}}\·[1-\cos \left(\frac{2\mathrm{\πx}}{L_0}\right)]---\left(8\right)$

B, calculating bow plate limiter of moment pressure F analytic expression.First force analysis is carried out to tower top and obtain F and balance arm draw-bar pull F ₃and lifting beam draw-bar pull F ₁, F ₂relation, then respectively force analysis is carried out to balance arm and lifting beam, obtains F ₁, F ₂, F ₃expression.When carrying out force analysis to lifting beam, because two suspension centre derrick runway girder is a hyperstatic structure, need to replace a wherein pull bar by superfluous constraint power to be reduced to statically determinate structure row Coordinate deformation equation and to calculate, in the process calculated when lift heavy be in outside link institute outside outside suspension centre, between inside and outside two pull bar place two suspension centres and in draw-in bar place within suspension centre time also need to discuss respectively.Result of calculation is as follows,

In formula (9), F ₁for the pulling force of lifting beam outside link (pull bar 1), F ₂for the pulling force of lifting beam draw-in bar (pull bar 2), F ₃for the pulling force of balance arm pull bar (pull bar 3), h _ifor tower top root installs bow plate limiter of moment place main chord and horizontal web member pad to the distance of pull bar i, i=1,2,3, h ₄for tower top root installs bow plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, α is the angle of pull bar 1 and vertical direction, β is the angle of pull bar 2 and vertical direction, and γ is the angle of pull bar 3 and vertical direction, L ₄for tower top root, the main chord of bow plate limiter of moment place main chord right opposite homonymy and horizontal web member pad and tower top root are installed to install and bend plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, L ₇install the distance of two homonymy truncation points between the main chord truncation surface of position for blocking bow plate limiter of moment, G is the counterweight of tower machine, L ₄for balance arm and tower top pin joint are to the distance of lifting beam and tower top pin joint, L ₅for counterweight barycenter is to the distance of balance arm and tower top pin joint, q ₁the intensity of balance arm uniformly distributed load, lift heavy when Q is the work of tower machine, q is the weight of suspender, L-lift heavy suspension centre D to the distance of lifting beam and tower top pin joint, L ₁for interior suspension centre C ₃to the distance of lifting beam and tower top pin joint, L ₂for outer suspension centre is to the distance of interior suspension centre, L ₃for outer suspension centre is to the distance of lifting beam outermost end points, g is local acceleration of gravity, q ₂for the intensity of lifting beam uniformly distributed load, δ ₁₁for unit load independent role lower link 2 truncation points is along the displacement of pull bar 2 place rectilinear direction, Δ _1Pfor at jib from heavy load q ₂, lift heavy Q and suspender heavy q effect lower link 2 truncation points along the displacement of its place rectilinear direction, E is the elastic modulus of material, and I is the cross sectional moment of inertia of material, A _aCfor the area of section of pull bar 2, A _aEfor the area of section of pull bar 1, K ₁for the section influence coefficient of load Q+q, K ₂for pull bar influence of arrangement coefficient, K ₃for bow plate installation site influence coefficient, K ₄for force constant in main chord, A ₃, A ₂, A ₁, A ₀for the section influence coefficient K of load Q+q ₁constant coefficient item in expression formula.

$\left\{\begin{array}{c}F=F_1(\cos \mathrm{\β}-\frac{h_4}{L_7}\sin \mathrm{\β}+\frac{h_1}{L_7})+F_2(\cos \mathrm{\α}-\frac{h_4}{L_7}\sin \mathrm{\α}+\frac{h_2}{L_7})+F_3(\cos \mathrm{\γ}+\frac{h_4}{L_7}\sin \mathrm{\γ}-\frac{h_3}{L_7})\\ F_1=\frac{L}{h_1}(Q+q)+\frac{q_2}{2h_1}{(L_1+L_2+L_3)}^2+\frac{{\mathrm{\Δ}}_{1P}}{h_1{\mathrm{\δ}}_{11}}{h}_2\\ F_2=-\frac{{\mathrm{\Δ}}_{1P}}{{\mathrm{\δ}}_{11}}\\ {\mathrm{\Δ}}_{1P}=K_1(Q+q)g+A=(A_3{L}^3+A_2{L}^2+A_{1}L+A_0)(Q+q)g+A\\ {\mathrm{\δ}}_{11}=\frac{L_1^2{L}_2{\left(\cos \mathrm{\α}\right)}^2}{\mathrm{EI}}+\frac{L_2{\left(h_2\cos \mathrm{\β}\right)}^2(3L_1^2+3L_1{L}_2+L_2^2)}{3h_1^2\mathrm{EI}}+\frac{L_1{L}_2{h}_2\cos \mathrm{\α}\·\cos \mathrm{\β}(2L_1+L_2)}{h_1\mathrm{EI}}+\\ \frac{L_2^2{(h_2\cos \mathrm{\β}-h_1\cos \mathrm{\α})}^2}{3h_1^2\mathrm{EI}}+\frac{L_1}{E{A}_{\mathrm{AC}}\sin \mathrm{\α}}-\frac{h_2(L_1+L_2)}{h_{1}E{A}_{\mathrm{AE}}\sin \mathrm{\β}}\\ F_3=\frac{L_4+L_5}{L_5{h}_3}(G\·L_5+\frac{1}{2}{q}_1{L}_5^2)\end{array}\right.---\left(9\right)$

3rd step: adopt above-mentioned computing formula to carry out designing and calculating to bow plate limiter of moment.When tower type number determine and preliminary selected bow plate limiter of moment structural parameters, adopt above-mentioned formulae discovery magnification and amount of deflection, see whether within the scope of request for utilization, and according to result of calculation, coupling is optimized to parameter.

2, described characteristic parameter matching method, carries out: 1) first calculate magnification according to the following steps, sees and whether meets the request for utilization being not less than 8; 2) calculate amount of deflection variable quantity, see whether to meet and change within the scope of 20 ~ 30mm; 3) when having at least one not meet request for utilization, adopting control variate method to change the structural parameters of bow plate limiter of moment successively, repeating step 1) and step 2), until magnification and amount of deflection variable quantity all meet request for utilization.

Invention effect: adopt characteristic parameter matching method of the present invention, the present invention is adopted to calculate magnification after primary election bow plate limiter of moment and whether amount of deflection meets request for utilization at selected tower type number, and then coupling is optimized to bow plate limiter of moment structural parameters, can guarantee to bend the availability of plate limiter of moment before the debugging of cantle plate limiter of moment installed by tower machine, improve its accuracy and sensitivity, make the debugging of bow plate limiter of moment become more simple, ensure the safe operation of tower machine.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the utility model is described in further detail:

Fig. 1 is method flow diagram of the present invention.

Fig. 2 is the specific embodiment of the invention with magnification change figure within interior suspension centre when the two suspension centre swing arm tower crane of QTZ160 and bow plate limiter of moment structural parameters are in particular range.

Fig. 3 is the specific embodiment of the invention with magnification change figure between two suspension centres when the two suspension centre swing arm tower crane of QTZ160 and bow plate limiter of moment structural parameters are in particular range.

Fig. 4 is the specific embodiment of the invention with magnification change figure outside outer suspension centre when the two suspension centre swing arm tower crane of QTZ160 and bow plate limiter of moment structural parameters are in particular range.

Fig. 5 is that the specific embodiment of the invention is for monolithic amount of deflection variation diagram when the two suspension centre swing arm tower crane of QTZ160 and special parameter bow plate limiter of moment.

Fig. 6 is that the specific embodiment of the invention is for the variation diagram of monolithic amount of deflection variable quantity when the two suspension centre swing arm tower crane of QTZ160 and special parameter bow plate limiter of moment.

Embodiment

As shown in fig. 1, this embodiment is for the two suspension centre swing arm tower crane of QTZ160, employing thickness is 8mm, the cambered plate limiter of moment (general selection material is Q235-A) that wide 50mm alloy structure steel plate manufactures, it bends high limited range is 20 ~ 40mm, it is 1000 ~ 1500mm that length of bow is defined as, and adopts structural parameter determining method of the present invention as follows:

The first step, calculates magnification analytic expression as follows:

A, the calculating bow plate deflection on bow plate limiter of moment axis of symmetry.First bow plate moment is limited it and carry out force analysis, get any differential of the arc section on cambered plate and calculate it and bend the deflection on plate limiter of moment axis of symmetry, higher order indefinite small is ignored by after power series expansion, then in whole length range, integration is carried out, obtain bending the deflection of plate on bow plate limiter of moment axis of symmetry

$\mathrm{\Δ}=\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(1\right)$

In above-mentioned formula (1), Δ is that bow plate is bending deflection total on plate limiter of moment axis of symmetry direction, and bow when a' is the limiter of moment work of bow plate is high, L " ₀for bending the length after plate occurs bending and deformation when tower machine works;

B, the maximum deformation quantity of calculating bow plate limiter of moment under pressure F effect.The deflection of bow plate on bow plate limiter of moment axis of symmetry is caused by two parts, Part I be due to pressure F cause tower owner chord member be out of shape cause at axis of symmetry axial support displacement amount Δ 1, Part II is self bending deformation quantity Δ 2 after bow plate inital bending

$\mathrm{\Δ}1=\frac{F{L}_0^{\′\′}}{\mathrm{EA}}---\left(2\right)$

$\mathrm{\Δ}2=\frac{{\mathrm{\π}}^2{a}^2}{L_0}---\left(3\right)$

Δ＝Δ1+Δ2 (4)

In above-mentioned formula (2), (3), (4), in formula Δ 1 for pressure F cause tower owner chord member be out of shape cause in the axial support displacement amount of symmetry, Δ 2 is the bending deformation quantity in x-axis direction after bow plate inital bending when tower machine works, F is main chord axle pressure, L' ₀for bow plate when bow plate is welded on tower owner chord member tentatively bending after length, E is the elastic modulus of tower owner chord member, and a is that bow plate is in the half perpendicular to maximum deformation quantity on axis of symmetry direction when not working for tower machine, and A is tower owner chord member sectional area;

C, calculating bow plate limiter of moment magnification analytic expression.Bow plate limiter of moment magnification is defined as bow High variation amount and the ratio of length of bow's variable quantity, bends length of bow L when plate limiter of moment works according to above-mentioned analysis " ₀expression formula and magnification analytic expression as follows,

$L_0^{\′\′}=L_0-\mathrm{\Δ}=L_0-\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(5\right)$

$k=\frac{\mathrm{\Δ}{a}^{\′}}{\mathrm{\Δ}{L}_0^{\′\′}}=\frac{\∂a^{\′}}{\∂L_0^{\′\′}}=\frac{L_0^2(F+\mathrm{EA})+2{\mathrm{\π}}^2{a}^2\mathrm{EA}}{2\mathrm{\π}\sqrt{\mathrm{EA}(L_0^2-{\mathrm{\π}}^2{a}^2)(L_0^{2}F+{\mathrm{\π}}^2{a}^2\mathrm{EA})}}---\left(6\right)$

Second step, calculates bow plate limiter of moment amount of deflection analytic expression in accordance with the following steps.Bow plate limiter of moment generally has three kinds of models: rectilinearity, circular arc and sinusoidal pattern, in view of sinusoidal pattern application is more, therefore the present invention calculates amount of deflection analytic expression for sinusoidal pattern bow plate limiter of moment, and all the other two profiles number can adopt same procedure to calculate.

A, calculating deflection curve equation.On sinusoidal pattern bow plate limiter of moment, any point amount of deflection ω meets deflection curve equation:

$\mathrm{\ω}=a^{\′}[1-\cos \left(\frac{2\mathrm{\πx}}{L_0^{\′\′}}\right)]---\left(7\right)$

In above-mentioned formula (7), x bends plate limiter of moment bottom for the displacement of any point on axis of symmetry direction on true origin bow plate.

Bring publicity (7) into according to the result of calculation of formula (1), (2), (3), (4), and consider that the distortion of tower owner chord member is less, can simplify line of deflection is expressed to result of calculation,

$\mathrm{\ω}=\sqrt{a^2+\frac{F{L}_0^2}{{\mathrm{\π}}^2\mathrm{EA}}}\·[1-\cos \left(\frac{2\mathrm{\πx}}{L_0}\right)]---\left(8\right)$

B, calculating bow plate limiter of moment pressure F analytic expression.First force analysis is carried out to tower top and obtain F and balance arm draw-bar pull F ₃and lifting beam draw-bar pull F ₁, F ₂relation, then respectively force analysis is carried out to balance arm and lifting beam, obtains F ₁, F ₂, F ₃expression.When carrying out force analysis to lifting beam, because two suspension centre derrick runway girder is a hyperstatic structure, need to replace a wherein pull bar by superfluous constraint power to be reduced to statically determinate structure row Coordinate deformation equation and to calculate, in the process calculated when lift heavy be in outside link institute outside outside suspension centre, between inside and outside two pull bar place two suspension centres and in draw-in bar place within suspension centre time also need to discuss respectively.Result of calculation is as follows,

In formula (9), F ₁for the pulling force of lifting beam outside link (pull bar 1), F ₂for the pulling force of lifting beam draw-in bar (pull bar 2), F ₃for the pulling force of balance arm pull bar (pull bar 3), h _ifor tower top root installs bow plate limiter of moment place main chord and horizontal web member pad to the distance of pull bar i, i=1,2,3, h ₄for tower top root installs bow plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, α is the angle of pull bar 1 and vertical direction, β is the angle of pull bar 2 and vertical direction, and γ is the angle of pull bar 3 and vertical direction, L ₄for tower top root, the main chord of bow plate limiter of moment place main chord right opposite homonymy and horizontal web member pad and tower top root are installed to install and bend plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, L ₇install the distance of two homonymy truncation points between the main chord truncation surface of position for blocking bow plate limiter of moment, G is the counterweight of tower machine, L ₄for balance arm and tower top pin joint are to the distance of lifting beam and tower top pin joint, L ₅for counterweight barycenter is to the distance of balance arm and tower top pin joint, q ₁the intensity of balance arm uniformly distributed load, lift heavy when Q is the work of tower machine, q is the weight of suspender, L-lift heavy suspension centre D to the distance of lifting beam and tower top pin joint, L ₁for interior suspension centre C ₃to the distance of lifting beam and tower top pin joint, L ₂for outer suspension centre is to the distance of interior suspension centre, L ₃for outer suspension centre is to the distance of lifting beam outermost end points, g is local acceleration of gravity, q ₂for the intensity of lifting beam uniformly distributed load, δ ₁₁for unit load independent role lower link 2 truncation points is along the displacement of pull bar 2 place rectilinear direction, Δ _1Pfor at jib from heavy load q ₂, lift heavy Q and suspender heavy q effect lower link 2 truncation points along the displacement of its place rectilinear direction, E is the elastic modulus of material, and I is the cross sectional moment of inertia of material, A _aCfor the area of section of pull bar 2, A _aEfor the area of section of pull bar 1, K ₁for the section influence coefficient of load Q+q, K ₂for pull bar influence of arrangement coefficient, K ₃for bow plate installation site influence coefficient, K ₄for force constant in main chord, A ₃, A ₂, A ₁, A ₀for the section influence coefficient K of load Q+q ₁constant coefficient item in expression formula.

$\left\{\begin{array}{c}F=F_1(\cos \mathrm{\β}-\frac{h_4}{L_7}\sin \mathrm{\β}+\frac{h_1}{L_7})+F_2(\cos \mathrm{\α}-\frac{h_4}{L_7}\sin \mathrm{\α}+\frac{h_2}{L_7})+F_3(\cos \mathrm{\γ}+\frac{h_4}{L_7}\sin \mathrm{\γ}-\frac{h_3}{L_7})\\ F_1=\frac{L}{h_1}(Q+q)+\frac{q_2}{2h_1}{(L_1+L_2+L_3)}^2+\frac{{\mathrm{\Δ}}_{1P}}{h_1{\mathrm{\δ}}_{11}}{h}_2\\ F_2=-\frac{{\mathrm{\Δ}}_{1P}}{{\mathrm{\δ}}_{11}}\\ {\mathrm{\Δ}}_{1P}=K_1(Q+q)g+A=(A_3{L}^3+A_2{L}^2+A_{1}L+A_0)(Q+q)g+A\\ {\mathrm{\δ}}_{11}=\frac{L_1^2{L}_2{\left(\cos \mathrm{\α}\right)}^2}{\mathrm{EI}}+\frac{L_2{\left(h_2\cos \mathrm{\β}\right)}^2(3L_1^2+3L_1{L}_2+L_2^2)}{3h_1^2\mathrm{EI}}+\frac{L_1{L}_2{h}_2\cos \mathrm{\α}\·\cos \mathrm{\β}(2L_1+L_2)}{h_1\mathrm{EI}}+\\ \frac{L_2^2{(h_2\cos \mathrm{\β}-h_1\cos \mathrm{\α})}^2}{3h_1^2\mathrm{EI}}+\frac{L_1}{E{A}_{\mathrm{AC}}\sin \mathrm{\α}}-\frac{h_2(L_1+L_2)}{h_{1}E{A}_{\mathrm{AE}}\sin \mathrm{\β}}\\ F_3=\frac{L_4+L_5}{L_5{h}_3}(G\·L_5+\frac{1}{2}{q}_1{L}_5^2)\end{array}\right.---\left(9\right)$

3rd step: adopt above-mentioned computing formula to carry out designing and calculating to bow plate limiter of moment.Substitute into the structural parameters respective value of the two suspension centre swing arm tower crane of QTZ160, bow is high presses limited range 20 ~ 40mm, whether length of bow presses limited range 1000 ~ 1500mm, calculates magnification and whether meets the request for utilization being not less than 8, and calculate its amount of deflection variable quantity and change within the scope of 20 ~ 30mm.

As shown in figs. 2 to 4, the specific embodiment of the invention is respectively with the two suspension centre swing arm tower crane of QTZ160 and the bow plate limiter of moment structural parameters magnification change figure outside magnification change figure and outer suspension centre between magnification change figure, two suspension centres within interior suspension centre when bending in high scope 20 ~ 40mm and length of bow's scope 1000 ~ 1500mm.From figure, when bending height and length of bow changes in setting range, when lift heavy is within interior suspension centre, between two suspension centres, outside outer suspension centre, magnification scope is respectively [1.28,3.12], [1.27,2.92], [1.26,2.95], magnification does not meet the request for utilization being not less than 8, therefore needs to change setting value.From Fig. 2 ~ 4, no matter suspension centre is within interior suspension centre, between two suspension centres or outside outer suspension centre, be all the high minimalization of bow and length of bow when getting maximum value magnification obtain maximal value, therefore need to reduce that bow is high increases length of bow.

As shown in Fig. 5 ~ 6, be respectively the specific embodiment of the invention bends plate amount of deflection variable quantity variation diagram for monolithic bow plate amount of deflection variation diagram when the two suspension centre swing arm tower crane of QTZ160 and special parameter bow plate limiter of moment and monolithic.From figure, bending plate amount of deflection and amount of deflection variable quantity and hoisting moment is similar to linear, when hoisting moment reaches specified hoisting moment, (high 40mm is bent under special parameter, length of bow 1400mm) monolithic amount of deflection variable quantity is maximum close to 4mm, for the symmetry due to its structure whole cambered plate limiter of moment, bow plate limiter of moment must be approximately 8mm by amount of deflection variable quantity, also do not change within the scope of the request for utilization of 20 ~ 30mm, therefore need the value changing bow height and length of bow, improving one's methods as reducing, bow is high increases length of bow.

The present invention accurately can calculate bow plate limiter of moment magnification and amount of deflection calculates, improve the problem that existing bow board-like limiter of moment ubiquity precision is not high, sensitivity is on the low side, the limiter of moment design of bow plate and sensitivity thereof are improved there is Theory and applications value, can judge whether the bow plate limiter of moment of certain structural parameters is applicable to the tower machine of specific model in advance, save the expense of trial-production and the time of debugging, made bow plate limiter of moment meet request for utilization simultaneously.

Claims (2)

1. the bow plate limiter of moment structural parameter determining method mated with tower machine, is characterized in that described method is carried out according to the following steps:

The first step, calculates magnification analytic expression as follows:

A, the calculating bow plate deflection on bow plate limiter of moment axis of symmetry.First bow plate moment is limited it and carry out force analysis, get any differential of the arc section on cambered plate and calculate it and bend the deflection on plate limiter of moment axis of symmetry, higher order indefinite small is ignored by after power series expansion, then in whole length range, integration is carried out, obtain bending the deflection of plate on bow plate limiter of moment axis of symmetry

$\mathrm{\Δ}=\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(1\right)$

In above-mentioned formula (1), Δ is that bow plate is bending deflection total on plate limiter of moment axis of symmetry direction, and bow when a' is the limiter of moment work of bow plate is high, L " ₀for bending the length after plate occurs bending and deformation when tower machine works;

B, the maximum deformation quantity of calculating bow plate limiter of moment under pressure F effect.The deflection of bow plate on bow plate limiter of moment axis of symmetry is caused by two parts, Part I be due to pressure F cause tower owner chord member be out of shape cause at axis of symmetry axial support displacement amount Δ 1, Part II is self bending deformation quantity Δ 2 after bow plate inital bending

$\mathrm{\Δ}1=\frac{{\mathrm{FL}}_0^{\′\′}}{\mathrm{EA}}---\left(2\right)$

$\mathrm{\Δ}2=\frac{{\mathrm{\π}}^2{a}^2}{L_0}---\left(3\right)$

Δ＝Δ1+Δ2 (4)

In above-mentioned formula (2), (3), (4), in formula Δ 1 for pressure F cause tower owner chord member be out of shape cause in the axial support displacement amount of symmetry, Δ 2 is the bending deformation quantity in x-axis direction after bow plate inital bending when tower machine works, F is main chord axle pressure, L' ₀for bow plate when bow plate is welded on tower owner chord member tentatively bending after length, E is the elastic modulus of tower owner chord member, and a is that bow plate is in the half perpendicular to maximum deformation quantity on axis of symmetry direction when not working for tower machine, and A is tower owner chord member sectional area;

C, calculating bow plate limiter of moment magnification analytic expression.Bow plate limiter of moment magnification is defined as bow High variation amount and the ratio of length of bow's variable quantity, bends length of bow L when plate limiter of moment works according to above-mentioned analysis " ₀expression formula and magnification analytic expression as follows,

$L_0^{\′\′}=L_0-\mathrm{\Δ}=L_0-\frac{{\mathrm{\π}}^2{a}^{\′2}}{L_0^{\′\′}}---\left(5\right)$

$k=\frac{\mathrm{\Δ}{a}^{\′}}{\mathrm{\Δ}{L}_0^{\′\′}}=\frac{\∂a^{\′}}{\∂L_0^{\′\′}}=\frac{L_0^2(F+\mathrm{EA})+2{\mathrm{\π}}^2{a}^2\mathrm{EA}}{2\mathrm{\π}\sqrt{\mathrm{EA}(L_0^2-{\mathrm{\π}}^2{a}^2)(L_0^{2}F+{\mathrm{\π}}^2{a}^2\mathrm{EA})}}---\left(6\right)$

Second step, calculates bow plate limiter of moment amount of deflection analytic expression in accordance with the following steps.Bow plate limiter of moment generally has three kinds of models: rectilinearity, circular arc and sinusoidal pattern, in view of sinusoidal pattern application is more, therefore the present invention calculates amount of deflection analytic expression for sinusoidal pattern bow plate limiter of moment, and all the other two profiles number can adopt same procedure to calculate.

A, calculating deflection curve equation.On sinusoidal pattern bow plate limiter of moment, any point amount of deflection ω meets deflection curve equation:

$\mathrm{\ω}=a^{\′}[1-\cos \left(\frac{2\mathrm{\πx}}{L_0^{\′\′}}\right)]---\left(7\right)$

In above-mentioned formula (7), x bends plate limiter of moment bottom for the displacement of any point on axis of symmetry direction on true origin bow plate.

Bring publicity (7) into according to the result of calculation of formula (1), (2), (3), (4), and consider that the distortion of tower owner chord member is less, can simplify line of deflection is expressed to result of calculation,

$\mathrm{\ω}=\sqrt{a^2+\frac{{\mathrm{FL}}_0^2}{{\mathrm{\π}}^2\mathrm{EA}}}\·[1-\cos \left(\frac{2\mathrm{\πx}}{L_0}\right)]---\left(8\right)$

B, calculating bow plate limiter of moment pressure F analytic expression.First force analysis is carried out to tower top and obtain F and balance arm draw-bar pull F ₃and lifting beam draw-bar pull F ₁, F ₂relation, then respectively force analysis is carried out to balance arm and lifting beam, obtains F ₁, F ₂, F ₃expression.When carrying out force analysis to lifting beam, because two suspension centre derrick runway girder is a hyperstatic structure, need to replace a wherein pull bar by superfluous constraint power to be reduced to statically determinate structure row Coordinate deformation equation and to calculate, in the process calculated when lift heavy be in outside link institute outside outside suspension centre, between inside and outside two pull bar place two suspension centres and in draw-in bar place within suspension centre time also need to discuss respectively.Result of calculation is as follows,

In formula (9), F ₁for the pulling force of lifting beam outside link (pull bar 1), F ₂for the pulling force of lifting beam draw-in bar (pull bar 2), F ₃for the pulling force of balance arm pull bar (pull bar 3), h _ifor tower top root installs bow plate limiter of moment place main chord and horizontal web member pad to the distance of pull bar i, i=1,2,3, h ₄for tower top root installs bow plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, α is the angle of pull bar 1 and vertical direction, β is the angle of pull bar 2 and vertical direction, and γ is the angle of pull bar 3 and vertical direction, L ₄for tower top root, the main chord of bow plate limiter of moment place main chord right opposite homonymy and horizontal web member pad and tower top root are installed to install and bend plate limiter of moment place main chord and horizontal web member pad and the distance between lifting beam and tower top pin joint, L ₇install the distance of two homonymy truncation points between the main chord truncation surface of position for blocking bow plate limiter of moment, G is the counterweight of tower machine, L ₄for balance arm and tower top pin joint are to the distance of lifting beam and tower top pin joint, L ₅for counterweight barycenter is to the distance of balance arm and tower top pin joint, q ₁the intensity of balance arm uniformly distributed load, lift heavy when Q is the work of tower machine, q is the weight of suspender, L-lift heavy suspension centre D to the distance of lifting beam and tower top pin joint, L ₁for interior suspension centre C ₃to the distance of lifting beam and tower top pin joint, L ₂for outer suspension centre is to the distance of interior suspension centre, L ₃for outer suspension centre is to the distance of lifting beam outermost end points, g is local acceleration of gravity, q ₂for the intensity of lifting beam uniformly distributed load, δ ₁₁for unit load independent role lower link 2 truncation points is along the displacement of pull bar 2 place rectilinear direction, Δ _1Pfor at jib from heavy load q ₂, lift heavy Q and suspender heavy q effect lower link 2 truncation points along the displacement of its place rectilinear direction, E is the elastic modulus of material, and I is the cross sectional moment of inertia of material, A _aCfor the area of section of pull bar 2, A _aEfor the area of section of pull bar 1, K ₁for the section influence coefficient of load Q+q, K ₂for pull bar influence of arrangement coefficient, K ₃for bow plate installation site influence coefficient, K ₄for force constant in main chord, A ₃, A ₂, A ₁, A ₀for the section influence coefficient K of load Q+q ₁constant coefficient item in expression formula.

$\left\{\begin{array}{c}F=F_1(\cos \mathrm{\β}-\frac{h_4}{L_7}\sin \mathrm{\β}+\frac{h_1}{L_7})+F_2(\cos \mathrm{\α}-\frac{h_4}{L_7}\sin \mathrm{\α}+\frac{h_2}{L_7})+F_3(\cos \mathrm{\γ}+\frac{h_4}{L_7}\sin \mathrm{\γ}-\frac{h_3}{L_7})\\ F_1=\frac{L}{h_1}(Q+q)+\frac{q_2}{2h_1}{(L_1+L_2+L_3)}^2+\frac{{\mathrm{\Δ}}_{1P}}{h_1{\mathrm{\δ}}_{11}}{h}_2\\ F_2=-\frac{{\mathrm{\Δ}}_{1P}}{{\mathrm{\δ}}_{11}}\\ {\mathrm{\Δ}}_{1P}=K_1(Q+q)g+A=(A_3{L}^3+A_2{L}^2+A_{1}L+A_0)(Q+q)g+A\\ {\mathrm{\δ}}_{11}=\frac{L_1^2{L}_2{\left(\cos \mathrm{\α}\right)}^2}{\mathrm{EI}}+\frac{L_2{\left(h_2\cos \mathrm{\β}\right)}^2(3L_1^2+3L_1{L}_2+L_2^2)}{3h_1^2\mathrm{EI}}+\frac{L_1{L}_2{h}_2\cos \mathrm{\α}\·\cos \mathrm{\β}(2L_1+L_2)}{h_1\mathrm{EI}}+\\ \frac{L_2^2{(h_2\cos \mathrm{\β}-h_1\cos \mathrm{\α})}^2}{3h_1^2\mathrm{EI}}+\frac{L_1}{{\mathrm{EA}}_{\mathrm{AC}}\sin \mathrm{\α}}-\frac{h_2(L_1+L_2)}{h_1{\mathrm{EA}}_{\mathrm{AE}}\sin \mathrm{\β}}\\ F_3=\frac{L_4+L_5}{L_5{h}_3}(G\·L_5+\frac{1}{2}{q}_1{L}_5^2)\end{array}\right.---\left(9\right)$

3rd step: adopt above-mentioned computing formula to carry out designing and calculating to bow plate limiter of moment.When tower type number determine and preliminary selected bow plate limiter of moment structural parameters, adopt above-mentioned formulae discovery magnification and amount of deflection, see whether within the scope of request for utilization, and according to result of calculation, coupling is optimized to parameter.

2. characteristic parameter matching method according to claim 1, is characterized in that: 1) first calculate magnification, sees and whether meets the request for utilization being not less than 8; 2) calculate amount of deflection variable quantity, see whether to meet and change within the scope of 20 ~ 30mm; 3) when having at least one not meet request for utilization, adopting control variate method to change the structural parameters of bow plate limiter of moment successively, repeating step 1) and step 2), until magnification and amount of deflection variable quantity all meet request for utilization.