CN104156587A - Static tension ratio skid resistance checking calculation method for friction increasing system - Google Patents

Abstract

The invention discloses a static tension ratio skid resistance checking calculation method for a friction increasing system. According to the friction increasing system, a non-dimensional coefficient method is adopted, and the static tension ratio c is introduced into analysis and research of system skid resistance safety on the basis of skid resistance safety conditions to obtain six kinds of static tension ratio models for skid resistance checking calculation. Meanwhile, the invention provides a calculation and configuration method for components of the increasing system, so that a simple, convenient and reliable theoretical basis is provided for system configuration optimization and skid resistance.

Description

A kind of Static tension ratio antiskid Checking Calculation method of friction winding system

Technical field

The present invention relates to a kind of Static tension ratio antiskid Checking Calculation method of friction winding system.

Background technology

Friction winding is to rely on the friction force of traction sheave to hoist ropes, realizes the lifting business ceasing to hold office of personnel and goods.The theoretical foundation of anti-skid safety---Euler's formula: the poor equilibrium relation with friction force of traction sheave both sides static(al).The inscape of Euler's formula: the skid-resistance coefficient e of the retarded velocity of both sides suspended mass, safety braking and friction force ^{f α}.It is the limit relation that part quality, skid-resistance coefficient and safety braking three elements combine together, and these three key elements are independent existence, are subject to again the restriction of anti-skidding condition.Any duty of friction winding, during as normal work when the size of magnitude of load, traffic direction, acceleration-deceleration and safety braking, all must meet the restriction of Euler's formula, just can reach the slip of control steel cable on wheel, this is the necessary satisfied Necessary and sufficient condition of friction winding.

Earlier 1900s late nineteenth century, electronic friction drive hoist is born, and is called Ge Beishi.Since oneth century, the anti-skidding problem of friction winding system, adopt to sound out checking method, i.e. first alternative pack, then carry out antiskid Checking Calculation if do not meet, then carries out gravity treatment, checks, until meet again.The method of friction hoisting antiskid checking computations, to there being different regulations without industry.

1 symbol definition

Payload ratings is Q _n(Kg), in friction pulley both sides, biggest quiet tension is T ₁g, Minimum Static tension force are T ₂g; The outstanding height of wire rope is H ₀(m), operation rated speed v (m/s), enclose wrap angle sigma;

Static tension ratio c, quiet antiskiding factor σ _j, Safety factor of moving anti-slide σ _d; Fully loaded falling-threshold retarded velocity a _3x, fully loaded rising limit retarded velocity a _3s; Coefficientoffrictionμ, dynamic friction coefficient μ _d; Equlvalent coefficient of friction f, dynamically equlvalent coefficient of friction f _d; Static skid-resistance coefficient e ^{f α}, dynamic skid-resistance coefficient .

2 antiskid Checking Calculation theoretical foundations

2.1 mine hoisting

In mine hoist industry, in mining handbook and coal rules, for meeting anti-skid safety, for different ruuning situation, provide different antiskid Checking Calculation methods, have quiet antiskid coefficient of safety method, Safety factor of moving anti-slide method, fully loaded falling-threshold Deceleration way and fully loaded rising limit Deceleration way, rules provide as follows:

(1) quiet antiskiding factor

During normal work, threshold friction is called antiskiding factor with the ratio of Tension Difference, rules regulation: the quiet antiskiding factor of only considering quiet tension force must be not less than 1.75, and quiet antiskiding factor is:

${\mathrm{\σ}}_j=\frac{T_2(e^{\mathrm{f\α}}-1)}{T_1-T_2}\≥1.75---\left(1\right)$

(2) Safety factor of moving anti-slide

While counting dynamic loading, Safety factor of moving anti-slide must be not less than 1.25, and Safety factor of moving anti-slide is:

${\mathrm{\σ}}_d=\frac{T_2(g-a)(e^{\mathrm{f\α}}-1)}{T_1(g+a)-T_2(g-a)}\≥1.25---\left(2\right)$

(3) fully loaded falling-threshold retarded velocity

During safety braking, rules regulation: fully loaded falling-threshold retarded velocity must be not less than 1.5m/s ², fully loaded falling-threshold retarded velocity is:

$a_{3x}=\frac{e^{\mathrm{f\α}}-c}{e^{\mathrm{f\α}}+c}\≥1.5m/s^2---\left(3\right)$

(4) fully loaded rising limit retarded velocity

Rules regulation: fully loaded rising limit retarded velocity must be not more than 5m/s ², fully loaded rising limit retarded velocity is:

$a_{3s}=\frac{c_{e^{\mathrm{f\α}}}-1}{c_{e^{\mathrm{f\α}}}+1}\≤5m/s^2---\left(4\right)$

In rules, recommend Static tension ratio c to get 1.4 or 1.5.

2.2 towed elevator

The antiskid Checking Calculation of towed elevator industry, GB GB7588-1995 and GB7588-2003, in European EN81-1:1998, all have the formula of anti-skid safety checking computations, is called anti-skidding condition.

In GB GB7588-1995, stipulate, the calculating formula of anti-skidding condition is:

$\frac{T_1}{T_2}{c}_1{c}_2\≤e^{\mathrm{f\α}}---\left(5\right)$

In formula (5): in the situation that be loaded with that the car of 125% rated load is positioned at minimum stop and unloaded car is positioned at top station, the larger quiet pulling force in the hoist ropes of traction sheave both sides and the ratio of less quiet pulling force;

C ₁the coefficient relevant with acceleration, retarded velocity and elevator special mounting situation, and the increase with travelling speed increases, get 1.1～1.25 and more than;

C ₂the influence coefficient that causes traction sheave channel section to change due to wearing and tearing, to V-type groove c ₂=1.2;

If by the Static tension ratio of overload 25%, change the Static tension ratio of rated load into, just must increase the correction factor c of an overload 25% _3,:

$c_3=1+0.25\frac{c^2-1}{c^2}$

The calculating formula of anti-skidding condition becomes:

$\frac{T_1}{T_2}{c}_1{c}_2{c}_3\≤e^{\mathrm{f\α}}---\left(6\right)$

Anti-skidding condition in standard GB/T 7588-2003 is called traction to be calculated, and by three kinds of operating modes, calculates:

(1) car loads and brake hard operating mode

Car loads and brake hard operating mode, should meet anti-skidding condition:

$\frac{T_1}{T_2}\≤e^{\mathrm{f\α}}---\left(7\right)$

(2) car is detained operating mode

Counterweight is pressed on impact damper, when traction machine rotates up, should meet the condition of skidding:

$\frac{T_1}{T_2}\≥e^{f^{\′}\mathrm{\α}}---\left(8\right)$

The implication of three kinds of operating modes and the numerical value of friction factor are as follows:

(1) car Loading conditions

static ratio, should 125% rated load be housed according to car, and consider that the least favorable situation of car when the diverse location of hoistway calculate, coefficientoffrictionμ=0.1;

(2) brake hard operating mode

dynamic ratio, should be according to car unloaded or when rated load is housed, in the least favorable situation of the diverse location of hoistway, calculate friction factor

(3) car is detained operating mode

static ratio, should be according to unloaded or rated load is housed, and consider that the least favorable situation of car when the diverse location of hoistway calculate, coefficientoffrictionμ=0.2;

From " elevator manufacture and installation safety standard " GB7588-1995 and 2003 national standards, about antiskid Checking Calculation formula, can find out that the Static tension ratio of overload 120% in " GB7588-1995 " is multiplied by two correction factor c ₁and c ₂for the Static tension ratio c of practical rated load checks, add the correction factor c of an overload 25% ₃, at this moment Static tension ratio is:

c≤e ^fα/c ₁c ₂c ₃

In GB7588-2003 version, adopt dynamic tension ratio to carry out antiskid Checking Calculation, for anti-skid safety is revised equlvalent coefficient of friction f, the secure data during with realistic operation (normally operation and brake hard).Dynamic friction coefficient μ to brake hard engineering in safety standard _dwith the pass of static friction coefficient μ be:

${\mathrm{\μ}}_d=\frac{1}{1+\frac{v}{10}}\mathrm{\μ}$

Equlvalent coefficient of friction is:

$f_d=\frac{1}{1+\frac{v}{10}}f=\frac{1}{1+0.1v}f$

Anti-skidding condition can be converted into dynamic tension ratio and static tension force is recently described.

(1) dynamic tension ratio

Omit running resistance, angle sheave resistance and without pulley blocks etc. heavy-tailed rope system, the dynamic tension ratio of anti-skidding condition is:

$\frac{T_1(g+a)}{T_2(g-a)}\≤e^{f_d\mathrm{\α}}$

(2) static warp tension ratio

By dynamic skid-resistance coefficient change static skid-resistance coefficient e into ^{f α}, must increase the correction factor of a friction factor static warp tension ratio is:

$\frac{T_1}{T_2}\≤\frac{e^{\mathrm{f\α}}}{c_1{c}_4}---\left(10\right)$

Summary of the invention

A kind of Static tension ratio antiskid Checking Calculation method that the present invention relates to friction winding system, described method comprises the steps:

First try to select container dead weight, calculate and select wire rope, wire-rope safety factor is checked, if do not meet, and necessary gravity treatment container dead weight, then check wire-rope safety factor; If meet the demands, carry out antiskid Checking Calculation.If do not meet, necessary gravity treatment container dead weight ..., repeatedly calculate, until till meeting.

Accompanying drawing explanation

By describing in more detail exemplary embodiment of the present invention with reference to accompanying drawing, above and other aspect of the present invention and advantage will become and more be readily clear of, in the accompanying drawings:

Fig. 1 is six kinds of Static tension ratios of antiskid Checking Calculation and e ^{f α}graph of a relation;

Fig. 2 is friction winding in mine system unit configuration design flow diagram.

Embodiment

Hereinafter, now with reference to accompanying drawing, the present invention is described more fully, various embodiment shown in the drawings.Yet the present invention can implement in many different forms, and should not be interpreted as being confined to embodiment set forth herein.On the contrary, it will be thorough with completely providing these embodiment to make the disclosure, and scope of the present invention is conveyed to those skilled in the art fully.

Hereinafter, exemplary embodiment of the present invention is described with reference to the accompanying drawings in more detail.

3 antiskid Checking Calculation Static tension ratio representations

Antiskid Checking Calculation method is varied, in mine hoisting field, while normally working, adopts the Y-factor method Y of quiet antiskid coefficient of safety method, moving anti-skid safety; During safety braking, adopt transfer heavily loaded limit Deceleration way, on carry heavily loaded limit Deceleration way.

In towed elevator industry, adopt additional three correction factor methods of Static tension ratio and dynamic tension than the correction factor method of additional friction factor.These antiskid Checking Calculation methods, are all according to actual test figure and operating experience, artificial formulation out.Therefore, all trades and professions all have anti-skidding computing method and the standard of oneself.In order to compare its anti-skid safety, now adopt the representation of unified Static tension ratio to carry out analysis and comparison.

The Static tension ratio c of 3.1 quiet antiskid coefficient of safety methods _j

Press formula (1), make Static tension ratio draw the Static tension ratio c that quiet antiskiding factor equals at 1.75 o'clock _jfor:

$c_j\≤\frac{3}{7}+\frac{e^{\mathrm{f\α}}}{1.75}---\left(11\right)$

Formula (11) shows: the Static tension ratio c of quiet antiskiding factor _jwith skid-resistance coefficient e ^{f α}be directly proportional.

The Static tension ratio c of 3.2 Safety factor of moving anti-slide methods _d

Press formula (2), make Static tension ratio draw the Static tension ratio c that Safety factor of moving anti-slide equals at 1.25 o'clock _dfor:

$c_d\≤(\frac{1}{5}+\frac{e^{\mathrm{f\α}}}{1.25})\frac{g-a}{g+a}---\left(12\right)$

Formula (12) shows: the Static tension ratio c of Safety factor of moving anti-slide _dwith skid-resistance coefficient e ^{f α}increase and increase, with the increase of acceleration-deceleration a, reduce.

3.3 fully loaded falling-threshold retarded velocity

Press formula (3), or have make Static tension ratio can show that fully loaded falling-threshold retarded velocity equals 1.5m/s ²time Static tension ratio c _xfor:

c _x≤0.735e ^fα (13)

3.4 fully loaded rising limit retarded velocity

Press formula (4), or by make Static tension ratio can show that fully loaded rising limit retarded velocity equals 5m/s ²time Static tension ratio c _sfor:

c _s≥3.079/e ^fα (14)

3.5 Static tension ratio direct command procedures

By stipulating in GB7588_1995, by formula (6), drawn the Static tension ratio c of Static tension ratio direct command procedure _j' be:

c _j′≤e ^fα/c ₁c ₂c ₃ (15)

3.6 dynamic tensions compare direct command procedure

By formula (10), can obtain dynamic tension than the Static tension ratio c of direct command procedure _d' be:

${c_d}^{\′}\frac{e^{\mathrm{f\α}}}{c_1{c}_4}=0.684e^{\mathrm{f\α}}---\left(16\right)$

Example calculation

The correlation parameter of friction winding system is: as heavy friction factor f=0.333, enclose cornerite speed v=2.5m/s, retarded velocity a=0.8m/s ², c ₁=1.25, c ₂=1.2, c ₃=1.1.

C _j, c _d, c _x, c _s, c _j', c _d' antiskid Checking Calculation result as shown in table 1.

Six kinds of antiskid Checking Calculation method sample results of table 1

The antiskid Checking Calculation relation of stipulating in mine hoisting field, while normally working, quiet, Safety factor of moving anti-slide must not be less than 1.75 and 1.25; During safety braking, the fully loaded limit retarded velocity declining must not be less than 1.5m/s ², the fully loaded limit retarded velocity rising must not be greater than 5m/s ².By these four regulations, as can be seen from Table 1: Static tension ratio c _j, c _d, c _xall with skid-resistance coefficient e ^{f α}be directly proportional, with e ^{f α}increase and increase, belong to the maximal value of Static tension ratio; And Static tension ratio c _swith e ^{f α}be inversely proportional to, with e ^{f α}increase and reduce, belonging to the minimum value of Static tension ratio.

Two kinds of antiskid Checking Calculation relations stipulating in towed elevator field, the one, Static tension ratio adds three correction factor c ₁, c _2,c ₃; Another is that dynamic tension is than an additional correction factor c ₄. its result is all and e ^{f α}be directly proportional, with e ^{f α}increase and increase, belong to the maximal value of Static tension ratio.

In mine hoisting, stipulate that these different correction factors are all relevant with elevator speed size, and the increase with operation maximal rate increases, Static tension ratio increases and to reduce with speed, and Method for Checking in mine hoisting, the Static tension ratio drawing has nothing to do with travelling speed size.

The relation of six kinds of antiskid Checking Calculation, all limiting Static tension ratio can not be excessive.Otherwise anti-skid safety reduces, and according to a large amount of various test figures and operating experience, sums up the various Method for Checking drawing, by formula (11)～(16), obtains Static tension ratio and the e of six kinds of Method for Checking ^{f α}relation, as shown in Figure 1.

To six kinds of antiskid Checking Calculation methods, adopt Static tension ratio representation, drawn computing formula and figure, to show the difference between them, its common objective is all to guarantee that wire rope is non-slip, the design of this method, all at definite friction factor f, wrap angle sigma, payload ratings Q _n(Kg), the outstanding high H of rated speed v (m/s) and wire rope ₀(m) and under the condition such as wire rope type, carry out the calculating of elevator system, system unit configuration design cycle as shown in Figure 2.

Fig. 2 shows: first try to select container dead weight, calculate and select wire rope, wire-rope safety factor is checked, if do not meet, and necessary gravity treatment container dead weight, then check wire-rope safety factor; If meet the demands, carry out antiskid Checking Calculation.If do not meet, necessary gravity treatment container dead weight ..., repeatedly calculate, until till meeting.

Conclusion

(1) c _j, c _d, c _x, c _j', c _d' are all maximal values of Static tension ratio c;

(2) e ^{f α}=2 o'clock, c _j> c _d> c _x> c _j' > c _d', but differ, not very large, c _sit is the minimum value of Static tension ratio.

(3) if equal 5m/s by the fully loaded rising limit retarded velocity of stipulating in rules ²time, at e ^{f α}=2 o'clock, c _sto be greater than c _x, the minimum value of c, much larger than the maximal value of c, is irrational;

(4) a _3s=4.5～4.0m/s ²time, the maximal value of Static tension ratio, is greater than minimum value, and Static tension ratio just has the selection of zone of reasonableness.The fully loaded rising limiting velocity a stipulating in mine hoisting rules _3s≤ 5m/s ², be rational.

The foregoing is only embodiments of the invention, be not limited to the present invention.The present invention can have various suitable changes and variation.All any modifications of doing within the spirit and principles in the present invention, be equal to replacement, improvement etc., within protection scope of the present invention all should be included in.

Claims (7)

1. a Static tension ratio antiskid Checking Calculation method for friction winding system, is characterized in that:

First try to select container dead weight, calculate and select wire rope, wire-rope safety factor is checked, if do not meet, and necessary gravity treatment container dead weight, then check wire-rope safety factor; If meet the demands, carry out antiskid Checking Calculation.If do not meet, necessary gravity treatment container dead weight ..., repeatedly calculate, until till meeting.

2. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

The Static tension ratio c that quiet antiskiding factor equals at 1.75 o'clock _jfor:

$c_j\≤\frac{3}{7}+\frac{e^{\mathrm{f\α}}}{1.75}$ 。

3. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

The Static tension ratio c that Safety factor of moving anti-slide equals at 1.25 o'clock _dfor:

$c_d\≤(\frac{1}{5}+\frac{e^{\mathrm{f\α}}}{1.25})\frac{g-a}{g+a}$ 。

4. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

Fully loaded falling-threshold retarded velocity equals 1.5m/s ²time Static tension ratio c _xfor:

c _x≤0.735e ^fα。

5. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

Fully loaded rising limit retarded velocity equals 5m/s ²time Static tension ratio c _sfor:

c _s≥3.079/e ^fα。

6. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

The Static tension ratio c of Static tension ratio direct command procedure _j' be:

c _j′≤e ^fα/c ₁c ₂c ₃。

7. the Static tension ratio antiskid Checking Calculation method of a kind of friction winding system as claimed in claim 1, is characterized in that:

Dynamic tension is than the Static tension ratio c of direct command procedure _d' be:

${c_d}^{\′}\≤\frac{e^{\mathrm{f\α}}}{c_1{c}_4}=0.684e^{\mathrm{f\α}}$ 。