RU2332542C1 - Device for control of dragline excavator implement - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: present invention relates to the mining industry and may be used for the control of dragline excavator implement during excavation. For this purpose, the device has lifting and pulling hoist motors controlled by speed control units of these motors, a lifting cable (LC) tension controller with the first input connected to the output of the LC tension selector, the second input connected to the output of the LC tension transducer, and the third input connected to the outputs of the main and two additional functional generators (FG) through switches. The controller output is connected to the input of the lifting hoist speed control unit. A signal from the pulling cable tension transducer is supplied to the FG inputs. The switches are controlled through a non-linear element with the inputs connected to the output of selector 1 and an excavation path transducer, and the output connected to the switch control inputs through diodes. The actuating contacts of these switches are connected into circuits switching one of the FG's to the third input of the LC tension controller.

EFFECT: increased capacity, reliability, and service life duration of dragline excavator due to adjusting lifting cable (LC) tension value in case of change of cut and soil hardness conditions.

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Description

The invention relates to the mining industry and can be used to control the working equipment of a dragline excavator during digging.

A device is known for controlling the movement of a dragline bucket when digging, comprising a digging path sensor connected to a programmer for tensioning the traction ropes, which is connected to the input of the tension regulator of the hoisting ropes via the tension regulator of the traction ropes, while the output of the latter is connected to the input of the speed control unit of the hoist winch motor [one].

A disadvantage of the known device is that to compensate for the increasing weight of the bucket when moving it along the face, a linear change in the reference signal at the input of the tension regulator of the hoisting ropes depending on the length of the digging path is adopted. Since the process of filling the bucket with soil has a non-linear characteristic, the adopted linear change of the reference signal at the input of the tension rope tension regulator leads either to overloading the working equipment and dragline lifting and traction mechanisms (with excessive deepening of the bucket into the ground), or to an increase in digging time and a decrease dragline performance (with insufficient penetration of the bucket into the ground).

The closest in technical essence to the proposed device is a device for controlling the working equipment of a dragline excavator, containing hoist and traction winch motors controlled by the respective speed control units of these engines, a hoist rope tension regulator, the first input of which is connected to the output of the hoist rope tensioner, the second its input - with the output of the tension sensor of the hoisting ropes, and the output of the regulator - with the speed control unit of the lifting winch, and the sensor to tension the traction rope, whose output is connected to an input main signal transducing function of the sensor drive signal hoisting ropes tension regulator.

The device allows to increase the reliability and durability of working equipment and dragline lifting and traction mechanisms by reducing dynamic loads arising in them when digging, and also to increase dragline performance by reducing digging time and time to clean the face when forming the face profile with a constant thickness of the chip cut by the bucket soil.

The disadvantages of this device include the fact that when generating a reference signal for the tension rope tension regulator, depending on the effort, the traction ropes do not take into account changes in the face and soil strength parameters, since the functional converter has a limited range of settings for the soil strength and bottom configuration.

In the process of digging, the strength of the soil, as well as the parameters of the face can vary. This requires reconfiguring the characteristics of the functional converter. If the characteristic of the functional converter is incorrectly selected, either the bucket may not be deep enough in the ground, which increases digging time and reduce dragline productivity, or vice versa, the bucket will be deeply buried in the soil, which increases the dynamic loads of working equipment and excavator-dragline mechanisms and reduces their reliability and durability.

The objective of the invention is to increase the productivity of a dragline excavator by reducing digging time and time to clean the face when forming its profile with a constant thickness of soil shavings cut by the bucket, as well as increasing the reliability and durability of working equipment and dragline lifting and traction winch mechanisms by reducing dynamic loads by adjusting the tension of the hoisting ropes taking into account the changing parameters of the bottom and soil strength.

This is achieved by the fact that the device for controlling the working equipment of the dragline excavator, containing hoist and traction winch engines, controlled by the respective speed control units of these engines, a hoist tension regulator, the first input of which is connected to the output of the hoist tension adjuster, its second input - with the output of the sensor for the tension of the lifting ropes, and the output of the regulator with the speed control unit of the lifting winch, and the tension sensor of the traction ropes, the output of which is connected to the input of the main functional converter of the signal of this sensor into the driving signal of the tension regulator of the lifting ropes, is equipped with two additional functional converters and controlled keys, a dial and a sensor for the digging path, as well as a non-linear element whose inputs are connected to the outputs of the master and the sensor for the digging path, and the output through diodes with control inputs of the keys, and the executive contacts of these keys are included in the circuit connecting one of the functional converters to the third input rope tension regulator.

Figure 1 presents a block diagram of the proposed device.

Figure 2 presents the characteristics of functional converters.

The device consists of working equipment of a dragline excavator in the form of a bucket 1 with lifting and traction ropes 2 and 3, lifting and traction winches 4 and 5, mechanically connected to the engines 6 and 7 of these winches, which are controlled by the speed control units 8 and 9 of these engines. At the input of the winch speed control unit 8, a control signal is supplied from the regulator 10 of the tension of the hoisting ropes, to the first input of which the adjuster 11 of the tension of the hoisting ropes is connected, to the second - a sensor 12 of the tension of the hoisting ropes. The engine 7 of the traction winch is connected to the sensor 13 of the digging path. The tension of the traction ropes is measured by means of a sensor 14, the output of which is connected to the inputs of the main and two additional functional converters 15, 16 and 17 of the output signal of this sensor into the driving signals of the regulator 10 of the tension of the hoisting ropes coming through the keys 18 and 19 to the third input of this regulator. The formation of control signals of the keys 18 and 19 is carried out by means of a nonlinear element 20, the inputs of which are connected to the outputs of the setter 21 and the sensor 13 of the digging path, and its output is through diodes 22, 23 with the control inputs of the keys 18, 19. The output of the main functional converter is connected to the controller 10 tension of the hoisting ropes through the contact 24 of the key 18 and the contact 25 of the key 19, and the outputs of the additional functional converters 16 and 17 are connected to the input of the regulator 10 of the tension of the hoisting ropes through the contacts 26 and 27, respectively boys 18 and 19.

Functional converters 15, 16 and 17 can be made in the form of adders, at the inputs of which are included non-linearity formation units of the type "dead zone".

The digger path setter 21 can be made in the form of an integrator (an operational amplifier with a resistor at the input and a capacitor in the feedback circuit), the input of which is supplied with a voltage corresponding to a given digging speed.

The sensor 13 of the digging path is made in the form of an integrator, the input of which receives a voltage corresponding to the current digging speed. Non-linear element 20 is a typical element with the characteristic "dead zone".

Before starting work on the basis of trial digging, the main and two additional transducers 15 and 16, 17 are set up in accordance with the following expression:

where U _m - the voltage at the output of the main and additional functional converters 15, 16, 17, corresponding to the specified tension of the hoisting ropes S ^m _pz ;

k = k ₁ ^m , k ₂ ^m , k ₃ ^m are the coefficients of the characteristics of the functional converters, which are determined for each of the converters from the expression:

m is the number corresponding to the numbering of the main and additional functional converters 15, 16, 17;

U _m ≡ S _t - voltage at the output of the sensor 14 of the tension of the traction contacts, corresponding to the force of their tension;

S _t.1 , S _t.2 , S _t.3 - the values of the tension of the traction ropes, at which there is a change in the slope of the characteristics of the functional converters;

S _since - the final value of the tension of the traction ropes (depending on the developed soils S _since = (0.8 ... 0.9) S _art. , where S _art. - stopping force of the traction ropes).

Characteristic S ¹⁵ _p.p. (S _t ) of the main transducer 15 is adjusted so that the predetermined tension of the hoisting ropes depending on the pulling force of the traction ropes is changed so as to ensure the tension of the hoisting ropes at which the face is formed with a constant thickness of the soil shavings cut by the bucket for conditions when the face parameters and the strength of the soil (rock) during excavation remains unchanged or changes slightly (see figure 2).

The additional functional converter 16 is configured so that its characteristic S ¹⁶ _p.z. (S _t ) had a lower slope compared to the characteristic S ¹⁵ _p.z. (S _t ) (i.e., k ¹⁶ _n <k ¹⁵ _n , n = 1, 2, 3).

Characteristic S ¹⁷ _p.p. (S _m) of the inverter 17 has a greater slope compared to the characteristic S ¹⁵ _p..z. (S _t ) of the converter 15 (k ¹⁷ _n > k ¹⁵ _n , n = 1, 2, 3) (see figure 2).

The digging path setter 21 is configured so that at a given digging speed, a predetermined digging path is provided. The length of the specified digging path L _k can be taken equal to:

where l _kov is the length of the bucket.

The value of the "dead zone" of the nonlinear element 20 is set so that it corresponds to the permissible deviation between the output signals of the setter 21 and the sensor 13 digging paths (between the set and the current value of the digging path):

where U ₂₁ ≡l _k.zad - output voltage setpoint digging path corresponding to a predetermined value digging path;

U ₁₃ ≡l _to - the output voltage of the digging path sensor, corresponding to the current value of the digging path;

± ΔU _21-13 - the magnitude of the deviation between the output voltages of the setter 21 and the sensor 13 digging paths;

± ΔU _add - the permissible deviation between the output voltages of the setter 21 and the sensor 13 digging paths;

± Δl _k - the deviation between the set and the current value of the digging path;

± Δl _k.dop - the permissible deviation between the target value and the current path of the digging.

The zero value of the characteristic S _PZ (S _t ) with S _t. ≤ S _{t. 1 is} provided for better penetration of the bucket into the ground at the beginning of the digging process.

After landing the bucket on the surface of the face, the driver turns the device on. Under the influence of the signal of the adjuster 11 of the tension of the lifting ropes, the slack in the lifting ropes is eliminated, and under the action of the traction mechanism, the bucket is moved along the bottom. The introduction of the bucket into the ground at the beginning of the digging process occurs under the influence of its weight. Further introduction of the bucket into the ground and maintaining a constant value of the thickness of the soil chips is ensured by regulating the tension of the hoisting ropes depending on the magnitude of the stress force in the traction ropes. The magnitude of this effort is determined by the increasing weight of the bucket, the increase in the forces of friction of the bucket on the ground and the forces of resistance to the movement of the prism of the drawing and soil in the bucket.

When moving the bucket along the face using a nonlinear element 20, the output signals of the setter 21 and the digging path sensor 13 are compared. If the deviation between the output voltages of the setter 21 and the digging path sensor 13 is less than the permissible value ± ΔU _21-13 <± ΔU _add and, therefore, the deviation between the preset and current digging path value is also less than the permissible value ± Δl _k <± Δl _{k. add} , the signal at the output of the nonlinear element 20 takes a zero value. In this case, the signal at the control inputs of the keys 18 and 19 is also equal to zero, and they are in the position when their contacts 24 and 25 are closed, and contacts 26 and 27 are open. As a result, the main functional converter 15 is connected to the third input of the hoist tension controller 10, and the hoist tension is controlled based on the reference signals generated by this converter. At the same time, the process of digging is controlled, which ensures the formation of a face with a constant thickness of soil chips.

If during digging there is a change in the parameters of the face or fortress of the soil and the current digging path, for example, is greater than the specified value l _k > l _k.zad and l _k.zad -l _k = -Δl _k <-Δl _k.dop (which takes place with insufficient penetration of the bucket into the ground), a negative polarity signal appears at the output of the nonlinear element 20, which is fed through the diode 22 to the control input of the key 18. In this case, contact 26 of this key 18 closes, and contact 24 opens. Functional converter 15 is disconnected from the input controller 10, the tension of the hoisting ropes, and instead connects the function generator 16 having a smaller slope characteristics _p.zad ¹⁶ S = f (S _m) as compared with the characteristic ¹⁵ _p.zad S = f (S _m) . There is a decrease in the specified tension of the hoisting ropes, which ensures an increase in the depth of the bucket in the ground and an increase in the soil shavings cut by the bucket.

If, when digging, the current value of the digging path becomes less than the set value l _k <l _k.zad and l _{k.zad. to} = Δl -l _to> Δl _k.dop (which occurs at considerable bucket burial in soil), the output of the nonlinear element 20 will signal a "positive" polarity, which is connected via a diode 23 to the control input of switch 19. When this contact 25 of this key is opened, and contact 27 is closed, providing connection to the input of the regulator 10 of the tension of the hoisting ropes instead of the functional transducer 16 of the transducer 17 having a large steepness of the output characteristic. The tension of the hoisting ropes increases, and the thickness of the soil shavings cut by the bucket decreases.

Thus, the proposed device allows you to adjust the magnitude of the tension of the hoisting ropes, taking into account changes in the parameters of the face and the strength of the soil, and therefore, to increase the productivity of the dragline excavator, as well as the reliability and durability of its working equipment and mechanisms of lifting and traction hoists.

Information sources

1. Auth. certificate No. 1333745 by class E02F 3/48, 9/20, Bull. No 32, 1987

2. Auth. certificate No. 1313962 by class E02F 3/48. Bull. No. 20, 1987 (prototype).

Claims (1)

A device for controlling the working equipment of a dragline excavator, containing hoist and traction winch engines, controlled by the respective speed control units of these engines, a hoist tension regulator, the first input of which is connected to the output of the hoist tension adjuster, its second input is the output of the hoist tension sensor and the regulator output - with a speed winch speed control unit, and a traction rope tension sensor, the output of which is connected to the input of the main function the local signal converter of this sensor into the driving signal of the tension regulator of the hoisting ropes, characterized in that it is equipped with two additional functional converters controlled by keys, a dial and a sensor for the digging path, as well as a non-linear element whose inputs are connected to the outputs of the master and the sensor for the digging path, and the output through diodes is with the control inputs of the keys, and the executive contacts of these keys are included in the circuit connecting one of the functional converters to the third input rope tension regulator.

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