CN102542123A - Pressure optimization computing method for hydraulic system of arm drawing mechanism - Google Patents

Abstract

The invention relates to a pressure optimization computing method for a hydraulic system of an arm drawing mechanism, in particular to a pressure optimization computing method for a hydraulic system of an arm drawing mechanism of a vehicle with a detachable carriage, which aims to provide a computing method of optimization of the maximum pressure of the hydraulic system during goods loading and unloading of the arm drawing mechanism of the vehicle with the detachable carriage. The technical scheme includes: the first step: building an optimized target function of a lifting oil cylinder; the second step: determining an optimized variable; the third step: designing restraint conditions; the fourth step: analyzing mechanism optimization; the fifth step: computing mechanism optimization; and the sixth step: designing the pressure of the hydraulic system according to the pressure computing results of the lifting oil cylinder. The pressure optimization computing method is used for pressure optimization design of the hydraulic system of the arm drawing mechanism.

Description

A kind of torque arm organization hydraulic pressure system pressure optimized calculation method

Technical field

A kind of torque arm organization hydraulic pressure of the present invention system pressure optimized calculation method relates to the computing method that a kind of torque arm organization hydraulic pressure system pressure is optimized, and relates in particular to the computing method that a kind of roll off skip loader torque arm organization hydraulic pressure system pressure is optimized.

Background technology

Roll off skip loader by the chassis, attach vehicle frame, elevating ram, pivoted arm, lift arm, telescopic arm and multiple directional control valve etc. and form; The flexible telescopic arm that makes that utilizes elevating ram will place ground compartment and place tote in the compartment to be pulled to attach on the vehicle frame or from attaching vehicle frame to be put back into ground; Owing to adopt the casing of sealing to come the transport and load thing; So can not cause secondary pollution to environment; The use of roll off skip loader has reduced working strength of workers, and because operating personnel's minimizing can be practiced thrift labour cost.Self-contained and the self-unloading in roll off skip loader compartment all is to be accomplished by the control of hydraulic system; And the pressure of hydraulic system depends on the pressure of elevating ram, and the calculating of elevating ram pressure adopts conventional method for designing to be difficult to the effect that reaches optimum, the result who causes or be that hydraulic system pressure is too small; Can not satisfy self-contained demand; Be that hydraulic system pressure is excessive, not only cause the instability of hydraulic system pressure, and increased the cost of setting up hydraulic system.

Summary of the invention

The present invention overcomes the deficiency that prior art exists, and technical matters to be solved provides the self-contained computing method that the maximum hydraulic pressure system pressure is optimized during with self-unloading of a kind of roll off skip loader torque arm mechanism.

In order to solve the problems of the technologies described above, the technical scheme that the present invention adopted is: a kind of torque arm organization hydraulic pressure system pressure optimized calculation method, carry out the hydraulic system pressure computation optimization according to following step:

The first step: set up the maximum minimum optimization aim function of maximum pressure minimum during with self-unloading of pressure when self-contained of elevating ram, the power that telescopic arm imposes on the compartment is hook power F1, attaches vehicle frame and is provided with two elevating rams;

Elevating ram pressure when self-contained: $\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="120217155146.png"\; state="\{\{state\}\}">P</figure-callout>}1=\frac{\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="120217155146.png"\; state="\{\{state\}\}">F</figure-callout>}1\&times;\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="120217155146.png"\; state="\{\{state\}\}">L</figure-callout>}1}{2[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2-\mathrm{\&pi;}{\left(\frac{d}{2}\right)}^2]\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}2}$

In the formula: F1---the compartment acts on that unit of force is on the hook: N;

L1---hook power arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

D---cylinder rod footpath unit is: m;

L2---the self-contained arm of force unit of oil cylinder is: m;

Elevating ram pressure during self-unloading: $\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">P</figure-callout>}2=\frac{G\&times;\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}3}{2\left[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2\right]L4}$

In the formula: G---compartment general assembly (TW) unit is: N;

L3---compartment gross weight arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

L4---oil cylinder self-unloading arm of force unit is: m;

Second step: the confirming of optimization variable; X and Y coordinate with the pin joint of the pin joint of pin joint, elevating ram and the subframe of lift arm and pivoted arm and lift arm and elevating ram primary importance are variable, and can meet design requirement with design variable numerical range and elevating ram cylinder barrel length and elongation is that constraint condition is come the torque arm Mechanism Optimization;

The 3rd step: design constraint; According to the working condition of equipment, from following two aspects majorized function is retrained, i.e. boundary constraint of design variable numerical range and elevating ram cylinder barrel length and elongation can meet design requirement, and initial point is the pin joint that attaches vehicle frame and pivoted arm;

First aspect, the variable-value range constraint;

Based on equipment size and arrangement requirement, to provide the permission excursion of each design variable in the design, each variable-value scope;

The constraint that meets design requirement of second aspect, elevating ram locating distance and elongation

In order to satisfy the designing requirement of oil cylinder, locating distance-elongation >=X, i.e. M-(N-M) >=X;

In the formula: M---elevating ram and the parasang that attaches between the primary importance of pin joint and lift arm and elevating ram pin joint of vehicle frame are: m;

N---elevating ram and the parasang that attaches between the second place of pin joint and lift arm and elevating ram pin joint of vehicle frame are: m;

X---elevating ram locating distance and elongation need satisfy designing requirement unit: m;

The second place of lift arm and elevating ram pin joint (4) is that the primary importance of lift arm and elevating ram pin joint obtains for 0 ° around the pin joint ROT13 of lift arm and pivoted arm;

The 4th step: Mechanism Optimization analysis; Multiple-objection optimization can convert single goal optimization into, changes objective function into self-contained pressure and self-unloading pressure and minimum, in constraint condition, increases a self-contained pressure simultaneously and equals self-unloading pressure;

The 5th step: Mechanism Optimization is calculated; MathCAD provides two to ask extremal function maximize (f, x, y;) and minimize (f, x, y;); Both can also can be used for finding the solution the extreme-value problem that satisfies certain constraint condition in the hope of the unconstrained extrema of function with them, these two functions return the value that makes function reach the variable of maximal value and minimum value respectively;

The 6th step: according to the calculation of pressure consequence devised system pressure of elevating ram.

The beneficial effect that the present invention compared with prior art has is: the step that is optimized calculating is: the first step: the optimization aim function of setting up elevating ram; Second step: the confirming of optimization variable; The 3rd step: design constraint; The 4th step: the Mechanism Optimization analysis, the 5th step: Mechanism Optimization is calculated, the 6th step: according to the calculation of pressure consequence devised system pressure of elevating ram; Computation optimization through the method can obtain the self-contained maximal value of the pressure of elevating ram during with self-unloading of torque arm mechanism; The hydraulic system that designs according to the maximal value of the elevating ram pressure that calculates gained; Not only can increase the stability of hydraulic system; And can also lower structural member intensity, thus practiced thrift the manufacturing cost of product, bring good economic benefit.

Description of drawings

Do further to specify below in conjunction with the accompanying drawing specific embodiments of the invention:

Fig. 1 is the structural representation that the present invention is in self-contained state;

Fig. 2 is the structural representation that the present invention is in the self-unloading state.

Among the figure 1 for the compartment, 2 for telescopic arm, 3 for lift arm, 4 the second places for lift arm and elevating ram pin joint, 5 for elevating ram, 6 for attach vehicle frame, 7 for the chassis, 8 for elevating ram and the pin joint that attaches vehicle frame, 9 for pivoted arm, 10 pin joints, 11 for lift arm and pivoted arm be that the pin joint, 12 that attaches vehicle frame and pivoted arm is the primary importances of lift arm and elevating ram pin joint.

Embodiment

Like Fig. 1, shown in Figure 2; With 14 tons of torque arm car computation optimization is that example is calculated; Roll off skip loader by compartment 1, chassis 7, attach vehicle frame 6, elevating ram 5, pivoted arm 9, lift arm 3, telescopic arm 2 and form; Hydraulic system pressure depends on the pressure of elevating ram 5, so the maximum pressure that only needs to calculate elevating ram 5 can be learnt the hydraulic system maximum pressure.

The first step: the confirming of objective function; The hydraulic system pressure of designing requirement roll off skip loader is minimum, and elevating ram 5 pressure comprise self-contained pressure, and are as shown in Figure 1; And self-unloading pressure, as shown in Figure 2, the power that telescopic arm 2 imposes on compartment 1 is hook power F1, is provided with two elevating rams 5 because attach vehicle frame 6, so it is calculated as:

Elevating ram 5 pressure when self-contained: $\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="120217155146.png"\; state="\{\{state\}\}">P</figure-callout>}1=\frac{\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="120217155146.png"\; state="\{\{state\}\}">F</figure-callout>}1\&times;\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="120217155146.png"\; state="\{\{state\}\}">L</figure-callout>}1}{2[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2-\mathrm{\&pi;}{\left(\frac{d}{2}\right)}^2]\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}2}$

In the formula: the unit of force that F1---compartment 1 acts on the telescopic arm 2 is: N;

L1---hook power arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

D---cylinder rod footpath unit is: m;

The self-contained arm of force unit of L2---oil cylinder is: m;

Elevating ram 5 pressure during self-unloading: $\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">P</figure-callout>}2=\frac{G\&times;\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}3}{2\left[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2\right]L4}$

In the formula: G---compartment 1 general assembly (TW) unit is: N;

L3---compartment gross weight arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

L4---oil cylinder self-unloading arm of force unit is: m;

Second step: the confirming of optimization variable; For reaching the minimum purpose of elevating ram 5 pressure, through the position of change key point, thereby analyze automatically, accomplish optimal design.Confirm that according to optimization aim the optimal design variable is the X and the Y coordinate of primary importance 12 of pin joint 8 and lift arm and elevating ram pin joint of pin joint 10, elevating ram and the subframe of lift arm and pivoted arm, totally 6 design variables.

The 3rd step: design constraint; According to the working condition of equipment, from following two aspects Optimization Model is retrained, i.e. boundary constraint of design variable numerical range and elevating ram 5 cylinder barrel length and elongation can meet design requirement.Initial point is the pin joint 11 that attaches vehicle frame and pivoted arm.

On the one hand, variable-value range constraint:

According to equipment size and arrangement requirement, to provide the permission variation range of each design variable in the design, each variable-value scope is shown in table ():

The variation range of table (one) design variable

On the other hand, elevating ram 5 locating distances and the elongation constraint that meets design requirement:

In order to satisfy the designing requirement of oil cylinder, locating distance-elongation >=X is got X=400, can get M-(N-M) >=400;

In the formula: M---elevating ram and the parasang that attaches between the primary importance 12 of pin joint 8 and lift arm and elevating ram pin joint of vehicle frame are: m;

N---elevating ram and the parasang that attaches between the second place 4 of pin joint 8 and lift arm and elevating ram pin joint of vehicle frame are: m;

X---elevating ram 5 locating distances and elongation need satisfy designing requirement unit: m;

The second place 4 of lift arm and elevating ram pin joint is that the primary importance 12 of lift arm and elevating ram pin joint obtains for 0 ° around pin joint 10 ROT13s of lift arm and pivoted arm; The coordinate X4 of the second place 4 of lift arm and elevating ram pin joint; Y4 can be through the coordinate X3 of triangle relation with the primary importance 12 of lift arm and elevating ram pin joint; Y3 draws relational expression, the coordinate X4 of the second place 4 of lift arm and elevating ram pin joint, and Y4 needn't be as optimization variable; Available X3, the expression formula of Y3 replaces;

The 4th step: Mechanism Optimization analysis; Multiple-objection optimization can convert single goal optimization into, changes objective function into self-contained pressure and self-unloading pressure and minimum, in constraint condition, increases a self-contained pressure simultaneously and equals self-unloading pressure.

The 5th step: Mechanism Optimization is calculated; MathCAD provide two ask extremal function maximize (f, x, y ...) and minimize (f, x, y ...), both can also can be used for finding the solution the extreme-value problem that satisfies certain constraint condition with them in the hope of the unconstrained extrema of function.These two functions return the value that makes function reach the variable of maximal value and minimum value respectively.

Known: compartment general assembly (TW) G=14 ton=140000 (N); F1=G/2=70000 (N); L1=2691mm; L3=1923mm

It is following that the input optimal design is found the solution order in the MathCAD worksheet:

X1=1295Y1=1 X2=4063 Y2=-138 X3=2115 Y3=118 input variable initial value

G=140000 F1=70000 L1=2691 L3=1923 assigned variable

$\mathrm{\&alpha;}=a\tan \left(\frac{Y3-Y1}{X3-X1}\right)$

$X4=X1-\sqrt{{(Y3-Y1)}^2+{(X3-X1)}^2}\mathrm{COS}(\mathrm{\&pi;}-0.714\mathrm{\&pi;}-\mathrm{\&alpha;})$

$Y4=\sqrt{{(Y3-Y1)}^2+{(X3-X2)}^2}\mathrm{Sin}(\mathrm{\&pi;}-0.714\mathrm{\&pi;}-\mathrm{\&alpha;})+\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="120217155146.png"\; state="\{\{state\}\}">Y</figure-callout>}1$

The coordinate X4 of the second place 4 of lift arm and elevating ram pin joint, Y4 uses X3, the Y3 expression formula

$\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}2=\frac{\sqrt{{\left(\frac{Y4-Y2}{X4-X2}\right)}^2+1}}{|\frac{Y4-Y2}{X4-X2}X1-\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="120217155146.png"\; state="\{\{state\}\}">Y</figure-callout>}1+Y2-X2\frac{Y4-Y2}{X4-\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">X</figure-callout>}2}|}$

$L4=\frac{\sqrt{{\left(\frac{Y3-Y2}{X3-X2}\right)}^2+1}}{|Y2-X2\frac{Y3-Y2}{X3-\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">X</figure-callout>}2}|}$

$P_{\mathrm{Min}}(\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="120217155146.png"\; state="\{\{state\}\}">X</figure-callout>}1,\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="120217155146.png"\; state="\{\{state\}\}">Y</figure-callout>}1,\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">X</figure-callout>}2,\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">Y</figure-callout>}2,\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="120217155159.png"\; state="\{\{state\}\}">X</figure-callout>}3,Y3)=\frac{\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="120217155146.png"\; state="\{\{state\}\}">F</figure-callout>}1\&times;\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="120217155146.png"\; state="\{\{state\}\}">L</figure-callout>}1}{2[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2-\mathrm{\&pi;}{\left(\frac{d}{2}\right)}^2]\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}2}+\frac{G\&times;\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}3}{2\left[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2\right]L4}$ The optimization aim function

Given

1200≤X1≤1450 4110≤X2≤4300 2160≤X3≤2255

10≤Y1≤50 -35≤Y2≤80 180≤Y3≤230

$\begin{array}{c}2\sqrt{{(Y3-Y2)}^2+{(X3-X2)}^2}-\sqrt{{(Y4-Y2)}^2+{(X4-X2)}^2}\&GreaterEqual;400\\ \frac{\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="120217155146.png"\; state="\{\{state\}\}">F</figure-callout>}1\&times;\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="120217155146.png"\; state="\{\{state\}\}">L</figure-callout>}1}{2[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2-\mathrm{\&pi;}{\left(\frac{d}{2}\right)}^2]\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="120217155146.png,120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}2}=\frac{G\&times;\mathrm{<figure-callout\; id="3"\; label="L"\; filenames="120217155159.png"\; state="\{\{state\}\}">L</figure-callout>}3}{2\left[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2\right]L4}\end{array}$ Constraint condition

P=Minimize (Pmin, X1, Y1, X2, Y2, X3, Y3) optimal design minimization function

$P=\left(\begin{array}{c}1228\\ 10\\ 4285\\ -38\\ 2160\\ 230\end{array}\right)$ Optimal design result

Last input P=will go out the result in MathCAD:

Self-contained pressure: P=17.765MPa;

Self-unloading pressure: P=17.541MPa.

The 6th step: according to the calculation of pressure consequence devised system pressure of elevating ram 5.

Claims (1)

1. torque arm organization hydraulic pressure system pressure optimized calculation method is characterized in that: carry out the hydraulic system pressure computation optimization according to following step:

The first step: set up the maximum minimum optimization aim function of maximum pressure minimum during with self-unloading of pressure when self-contained of elevating ram, the power that telescopic arm (2) imposes on compartment (1) is hook power F1, attaches vehicle frame (6) and is provided with two elevating rams (5);

Elevating ram pressure when self-contained: $P1=\frac{F1\&times;L1}{2[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2-\mathrm{\&pi;}{\left(\frac{d}{2}\right)}^2]L2}$

In the formula: F1---the compartment acts on that unit of force is on the hook: N;

L1---hook power arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

D---cylinder rod footpath unit is: m;

L2---the self-contained arm of force unit of oil cylinder is: m;

Elevating ram pressure during self-unloading: $P2=\frac{G\&times;L3}{2\left[\mathrm{\&pi;}{\left(\frac{D}{2}\right)}^2\right]L4}$

In the formula: G---compartment general assembly (TW) unit is: N;

L3---compartment gross weight arm of force unit is: m;

D---oil cylinder cylinder diameter unit is: m;

L4---oil cylinder self-unloading arm of force unit is: m;

Second step: the confirming of optimization variable; X and Y coordinate with the pin joint (12) of the pin joint (8) of pin joint (10), elevating ram and the subframe of lift arm and pivoted arm and lift arm and elevating ram primary importance are variable, and can meet design requirement with design variable numerical range and elevating ram (5) cylinder barrel length and elongation is that constraint condition is come the torque arm Mechanism Optimization;

The 3rd step: design constraint; Working condition according to equipment; From following two aspects majorized function is retrained; Boundary constraint and elevating ram (5) the cylinder barrel length and the elongation that are the design variable numerical range can meet design requirement, and initial point is the pin joint (11) that attaches vehicle frame and pivoted arm;

First aspect, the variable-value range constraint;

Based on equipment size and arrangement requirement, to provide the permission excursion of each design variable in the design, each variable-value scope;

The constraint that meets design requirement of second aspect, elevating ram (5) locating distance and elongation

In order to satisfy the designing requirement of oil cylinder, locating distance-elongation >=X, i.e. M-(N-M) >=X;

In the formula: M---elevating ram and the parasang that attaches between the primary importance (12) of pin joint (8) and lift arm and elevating ram pin joint of vehicle frame are: m;

N---elevating ram and the parasang that attaches between the second place (4) of pin joint (8) and lift arm and elevating ram pin joint of vehicle frame are: m;

X---elevating ram (5) locating distance and elongation need satisfy designing requirement unit: m;

The second place of lift arm and elevating ram pin joint (4) is that the primary importance (12) of lift arm and elevating ram pin joint obtains for 0 ° around pin joint (10) ROT13 of lift arm and pivoted arm;

The 4th step: Mechanism Optimization analysis; Multiple-objection optimization can convert single goal optimization into, changes objective function into self-contained pressure and self-unloading pressure and minimum, in constraint condition, increases a self-contained pressure simultaneously and equals self-unloading pressure;

The 5th step: Mechanism Optimization is calculated; MathCAD provides two to ask extremal function maximize (f, x, y;) and minimize (f, x, y;); Both can also can be used for finding the solution the extreme-value problem that satisfies certain constraint condition in the hope of the unconstrained extrema of function with them, these two functions return the value that makes function reach the variable of maximal value and minimum value respectively;

The 6th step: according to the calculation of pressure consequence devised system pressure of elevating ram.

Images