RU2021968C1 - Crane boom mechanism - Google Patents

Abstract

FIELD: materials handling equipment. SUBSTANCE: crane boom mechanism has boom hinge-connected with crane platform body, boom fly jib hinge-connected boom, hydraulic cylinders, controlled distributor and automatic system to provide horizontal transportation of load. Mechanism has potentiometer transducers installed in hinge joints of boom and fly jib which are connected into bridge circuit. Resistance of potentiometer transducers is selected to provide required relationship. EFFECT: enlarged operating capabilities. 2 dwg

Description

 The invention relates to hoisting machines, mainly to jib self-propelled cranes.

 Known boom devices for cranes, the hydraulic actuator of which includes a hydraulic cylinder for raising and lowering the boom, and the boom is equipped with an articulated jib, the angle of which is changed using a flexible guy. The hydraulic cylinders are controlled by a manually operated distributor, a hydraulic lock is attached to its piston cavity, and a brake valve is installed to smoothly lower the boom.

 The drives for raising and lowering the boom and the inclination of the jib in these devices do not provide automatic horizontal movement of the load when the angles of the boom or jib are changed, which reduces productivity during installation work, and the use of flexible braces complicates the design of the jib device.

 A device with a hydraulic drive of articulated articulated parts of a crane jib connected by a hydraulic cylinder is also known. This device also used flexible braces, the storage of which allows you to get a load path close to horizontal when changing the angle between the articulated parts of the boom. The disadvantage of this device is the complexity of the design of the boom device due to the use of two drives - a hydraulic winch and a change in length with flexible braces, in addition, the presence of flexible braces causes an increase in the size of the boom device and engine room due to the need to install an additional winch.

 The aim of the invention is to reduce the metal consumption of the boom device while automatically providing horizontal load by tilting the boom.

180^°-

+arcsin

sinα -

, где R₁ - сопротивление датчика угла наклона стрелы, Ом;
R₂ - сопротивление датчика наклона гуська, Ом;
R_o1, R_o2 - начальные сопротивления реохордов датчиков, Ом;
α - угол наклона стрелы, град.;
L - длина стрелы, м;
l - длина гуська, м;
Н - высота от шарнира стрелы до нижней точки гуська, м.This is achieved by the fact that the system for automatically ensuring horizontal load transfer includes potentiometric tilt angle sensors installed in the hinges of the boom and jib and an amplifier through which the resistance of the sensors connected to each other via a bridge circuit is connected to the control circuit of the distributor of the jib tilt cylinder; the resistance of the angle sensors are made according to the dependencies
R ₁ = R _o1 ˙α,
R ₂ = R

180 ^° -

+ arcsin

sinα -

where R ₁ is the resistance of the sensor angle of the boom, Ohm;
R ₂ - resistance of the tilt sensor jib, Ohm;
R _o1 , R _o2 - initial resistance of the sensor reohords, Ohm;
α - boom angle, degrees;
L is the length of the boom, m;
l is the length of the jib, m;
N - height from the hinge of the boom to the bottom point of the jib, m.

 Fulfillment of the sensor resistances according to the indicated dependences makes it possible to obtain horizontal laws of movement of the lower point of the jib when the boom angle is changed. A comparative analysis of the proposed solution with the prototype shows that the claimed device is characterized in that instead of a system of flexible guy wires, hinge and jib angle sensors are installed in the hinges, connected through an amplifier to a distributor with an electromagnetic drive, and the sensor resistances are made according to the proposed dependencies. Thus, the claimed device meets the criterion of "novelty." Comparison of the proposed solution with other hydraulic schemes of hoisting-and-transport machines did not reveal the claimed features in them, which allows us to conclude that the criterion of "significant differences" is met.

 In FIG. 1 shows a diagram of a crane jib device; figure 2 - connection diagram of the sensors.

 The jib device of the crane includes an arrow 1 with a potentiometric sensor 2 of the angle of inclination, including resistance 3, mounted in the lower hinge of the boom. In the upper hinge of the boom and jib boom 4, a potentiometric sensor 5 of the angle of inclination of the jib boom with resistance 6 is installed. Boom 1 and boom jib 4 are pivotally connected to the hydraulic cylinder 7 of the angle of inclination of the jib boom, which is connected by pipelines to a controlled fluid distributor 8, whose electromagnets 9 are through an amplifier 10 are connected with resistances 3, 6 of the angle sensors of the boom 1 and the jib 4.

 To ensure safety and smoothness, the piston cavity of the hydraulic cylinder is connected through a hydraulic lock 11 and a brake valve 12 to the distributor.

 The device operates as follows.

When changing the angle of the boom α proportionally changes the resistance 3 of the sensor 2 according to the linear law R ₁ = = R _o1 ˙ α. The resistance 6 of the sensor 5 is connected to the resistance 3 and pre-balanced. The angle sensors are connected according to the bridge circuit shown in figure 2. When the resistance 3 changes, an electric signal occurs, which is fed through an amplifier 10 to one of the electromagnets 9 of the distributor 8, causing it to operate and move the rod of the hydraulic cylinder 7, which changes the angle of inclination of the jib.

 When the angle γ is changed, the resistance 6 changes to the leveling value with the resistance 3, and the electric signal to the electromagnets 9, including the operation of the hydraulic cylinder 7, is stopped.

Thus, when the angle α changes, the angle γ automatically changes. The horizontal movement of the load with a change in the angle α is provided under the condition H = const and the required ratio α = f (γ). Based on the geometric relationships (Fig. 1), the relationship between the angles α = f (β) is represented as
L sin α = l sin β + H, (1) where β is the angle of inclination of the jib relative to the horizontal plane.

sinα -

, (3) а угол γ=180^o-(α+β) формулой
γ=180^°-

+arcsin

sinα -

(4)
Равенство сопротивлений датчиков 2,5 обеспечивается при законах изменения сопротивления
R₁ = f (α) и R₂ = f (γ) (5)
На основании выражения (4) при линейном законе изменения сопротивления 3
R₁ = R_o1 ˙α , (6) закон изменения сопротивления 6 определяется формулой
R₂=R₀₂·γ=R

180^°-

+arcsin

sinα -

. (7)
Таким образом, при выполнении сопротивлений 3, 6 изменения по законам (6), (7), наклон стрелы на угол α вызывает сопротивление датчика 2, которое не соответствует величине R₂ сопротивления датчика 5. Электрический сигнал вызывает срабатывание гидроцилиндра 7 и изменения угла γ , в результате чего сопротивление 6 изменяется по закону R₂ = f(γ) по уравнению (7), в результате чего перемещение штока гидроцилиндра изменением угла α "следит" за углом γ по условию горизонтального перемещения.The load moves horizontally when the ratio
L sin α - l sin β = Н = const, (2) from expression (2) the function γ = f (β) is described by the formula
β = arcsin

sinα -

, (3) and the angle γ = 180 ^o - (α + β) by the formula
γ = 180 ^° -

+ arcsin

sinα -

(4)
Equality of resistances of sensors 2.5 is ensured under the laws of resistance change
R ₁ = f (α) and R ₂ = f (γ) (5)
Based on the expression (4) with the linear law of resistance change 3
R ₁ = R _o1 ˙α, (6) the law of change of resistance 6 is determined by the formula
R ₂ = R ₀₂ γ = R

180 ^° -

+ arcsin

sinα -

. (7)
Thus, when performing resistances 3, 6, changes according to the laws of (6), (7), tilting the boom to the angle α causes the resistance of the sensor 2, which does not correspond to the value of R _{2 of the} resistance of the sensor 5. An electric signal triggers the hydraulic cylinder 7 and changes the angle γ , as a result of which the resistance 6 changes according to the law R ₂ = f (γ) according to equation (7), as a result of which the displacement of the hydraulic cylinder rod by changing the angle α "monitors" the angle γ according to the condition of horizontal movement.

 The use of the proposed device, for example, on modern pneumatic wheel cranes can reduce the frequency of inclusion of the tilt boom and jib drive when moving the load horizontally. With the lifting mechanism, the load is set to a height N, the tilt of the jib automatically changes the angle of the jib without switching the drives, which reduces the time to feed the load to a given place, and the absence of flexible braces and the winch of the jib drive reduces the metal consumption of the crane jib.

Claims (1)

CRANE BOOM DEVICE, comprising a boom pivotally connected to a crane platform, pivotally coupled to a jib boom, hydraulic cylinders for raising and lowering the boom and the tilt of the jib, a controlled distributor through which the cavities of the jib tilt cylinder are connected to the pressure and drain lines, and an automatic horizontal transfer system cargo, characterized in that, in order to reduce the metal consumption of the boom device, the system for automatically ensuring horizontal transfer of cargo includes tanovlenii a hinged boom and jib angles potentiometric sensors and amplifier through which the sensor resistance, interconnected in a bridge circuit, connected to the distributor jib tilt cylinder control circuit, wherein the sensor resistance angles formed by dependencies
R ₁ = R ₀₁ ˙ α;
R ₂ = R

180 ^° -

+ arcsin

sinα -

,
where R ₁ is the resistance of the sensor angle of the boom, Ohm;
R ₂ - resistance of the sensor of a tilt angle of a jib, Ohm;
R ₀₁ , R ₀₂ - initial resistance of the sensor reohords, Ohm;
α - boom angle, degrees;
L is the length of the boom, m;
l is the length of the jib, m;
H - height from the hinge of the boom to the bottom point of the jib, m.

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