RU2436900C2 - Earth excavation control method and excavator for its implementation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: control method of earth excavation by installing the grab into the working face, its movement with drives of head and lifting till filling, turning from the working face and unloading; at that, at initial excavating stage there performed is continuous monitoring of turn angle of saddle bearing with handle and vertical; at angle values <6° the head force is decreased to restriction (stop) value. Excavator includes undercarriage with roller disk on which there installed is turning platform with provided body, cabin, actuators, turning and lifting mechanisms, control system, jack boom made in the form of front and rear two-beam structures, working equipment including arm, saddle bearing, grab with handle installed in saddle bearing. Head reduction gear with rack gear and electric motor are arranged on the arm connected by means of back stays to jack boom. On the arm, in attachment zone of saddle bearing there installed is turn angle sensor of saddle bearing, which is connected to electric actuator control system. At that, lifting mechanism is arranged in close proximity to rear edge of turning platform. Actuators and turning mechanisms are arranged between rear beams of jack boom above the roller disk.

EFFECT: automatic operational control of position of grab with handle by means of monitoring of saddle bearing position.

2 cl, 2 dwg

Description

The invention relates to mining machines intended for the development of minerals and overburden rocks with loading in vehicles, as well as for the formation of dumps.

When conducting open pit mining of mineral deposits by mining excavators, there are critical modes of operation of machines and mechanisms that require external forced load limitation. For example, at the beginning of scooping, when the excavator bucket is thrown to the tracks of the undercarriage as much as possible, the arrow rises, the so-called “throw” of the arrow occurs. After the “casting” of the boom, it should fall forward, which causes negative dynamic loads in the structural components of the machine. To exclude the operation of machines in critical conditions, various control methods and automatic prohibition are used.

Known excavator (US 648073 B1, 2002.11.12), including a control device for the lift engine, sensors for monitoring the speed and torque of the lift engine, as well as a control mechanism for the pressure motor, namely a torque sensor and a speed sensor for moving the handle to the boom when the speed of the lift motor is lower than the lower speed value with high torque, and to allow the bucket to move away from the boom when the engine speed exceeds the lower speed value or there is no large torque.

The excavator contains a linear displacement sensor mounted on the platform, and a rod that is attached to the boom at one end and attached to the linear displacement sensor at the other end, the movement of the rod changes its position, a mechanism for determining the position of the linear displacement sensor and PLC - programmable controller, associated with the mechanism for determining the position of the linear displacement sensor and the control mechanism of the pressure motor for moving the bucket handle to the boom as a response to the indication of the mechanism that position linear encoder has changed in relation to the set point.

A known method and device for monitoring the load mode of a dragline or electric bucket excavator (RU 2311511 C2, 11/27/2007), and more particularly to a method and device for monitoring the load conditions of the boom. The invention allows continuous monitoring of orientation in accordance with the plane of the boom axis or along the orientation axis of the dragline or bucket excavator. For this, a dragline (single bucket excavator) contains an arrow, a bucket, hoisting and traction ropes. With the help of technical means, orientation data are generated relative to the plane containing the axis of the boom and at least one of the following elements of the group consisting of a hoisting rope, boom, bucket. This data is used to control the load mode based on the state of the dragline or electric bucket excavator. Information about orientation and / or disorientation is fed into the control system to automate the response to the overload mode detected in this way and to control the maximum voltage in the structure. Therefore, it is possible to modify the control actions so that during the application of controlled overload there is no excessive (dangerous) voltage. The method provides physical coupling of the hoisting rope to the sensor and orientation data is obtained by detecting the lateral deviation of the boom from the axis. Variants of the method are proposed depending on the type of sensors used (including contactless). But the method does not seem reliable, because several variables are used and measurements are carried out in dynamics, therefore, it is very doubtful to quickly eliminate boom overloads.

As a prototype, the management and design of a career crawler excavator, type EKG-10 were selected (career crawler excavators, type EKG-10. Operation manual 3536.00.00.000RE, OAO Izhorskiye Zavody, St. Petersburg, 2000, p. 11, 15, 19, 45).

The excavator consists of a running trolley with a roller circle, working equipment and mechanisms with a control system mounted on a turntable. The mechanisms on the turntable are closed by the body. In front of the platform, a driver's cab is installed. Also on the turntable is a biped rack consisting of a rear and front two-beam structures. The two-legged stand is connected by cables to the boom, serves for its fastening and transmission of forces arising when digging soil on the turntable of the excavator. The double-beam boom consists of two articulated sections, the lower section of the fifth boom is fixed in the brackets of the front of the platform. A single girder handle is mounted inside the boom. The saddle bearing with liners is a steel casting in which rollers are mounted on the axles, which are the support of the handle in a vertical plane. A saddle bearing is installed on the pressure axis on sliding bearings, rotates in a vertical plane on the pivots of the boom. The operation of the excavator is carried out as follows: at the beginning of digging, the bucket is installed at the excavator's standing level and the bottom is worked up by pressure and lift drives in such a way as to ensure filling of the bucket, which is then transferred to unloading. The installation of the bucket at the beginning of digging, the implementation of lifting and turning pressure operations, depends on the skills and techniques of the driver, i.e. the exception of overloading mechanisms subjectively depends on the qualifications of the driver.

An object of the invention is to provide automatic operational control of the position of the bucket with the handle, by monitoring the position of the saddle bearing, to create the optimal pressure force at the beginning of digging and the most rational load distribution on the turntable of the excavator.

The problem is solved by managing the excavation of the soil by installing the bucket in the bottom, moving it with pressure and lift drives until filling, turning from the bottom and unloading, and at the initial stage of digging, they continuously monitor the angle of rotation of the saddle bearing with the handle and the vertical, with an angle value of ≤6 ° force head is reduced to a value determined by the formula:

where S _n - pressure force;

S _p - lifting force, implemented at the beginning of digging;

R _c l _c - reaction in the arrow from the handle and the shoulder of its action;

G _i - the weight of the nodes on the boom (metal, pressure head drive, platforms, head blocks, electric motor);

l _i - the shoulder action of the corresponding weight relative to the axis of attachment of the boom to the turntable;

k is the safety margin of the boom specified during design at the time of digging;

l _1n - the shoulder action of the lifting force (S _p ), implemented at the beginning of digging relative to the axis of attachment of the boom in the rope, going from the head units to the bucket;

l _2n is the shoulder of the lifting force (S _p ), implemented at the beginning of digging relative to the axis of attachment of the boom in the rope going from the head blocks to the drum of the lifting winch;

l _n - the shoulder action of the pressure force (S _n ).

The excavator for carrying out the method comprises a running trolley with a roller circle on which a turntable is mounted with a body, a cab, drives, swing and hoist mechanisms, an electric drive control system, a biped, made in the form of front and rear two-unit structures, working equipment, including an arrow, a saddle bearing, a bucket with a handle mounted in a saddle bearing. A pressure reducer with a kremalery gear and an electric motor are placed on an arrow connected by cables to the biped. On the boom, in the area of attachment of the saddle bearing, a saddle bearing angle sensor is installed, connected to the electric drive control system, the lifting mechanism is placed as close as possible to the rear end of the turntable. Drives and turning mechanisms are placed between the rear beams of the biped rack above the roller circle.

Automatic operational control of the position of the bucket is carried out using a sensor that detects the rotation of the saddle bearing with a handle relative to the boom and connected to the control system. If this angle of inclination of the handle relative to the vertical is ≤6 °, then the boom can tip over towards the biped around the attachment point to the turntable, since in this position of the bucket with the handle the branch of the hoisting rope going directly to the bucket approaches the boom and the safety factor of the boom decreases. When lifting the bucket, starting from the angle of inclination of the handle to the vertical of 6 °, the branch of the hoisting rope moves away from the boom and the stability margin of the boom increases. The magnitude of the pressure force (S _n ) in the area of the angle of inclination of the handle relative to the vertical ≤6 ° for each particular excavator is calculated empirically, it depends on the weight and size characteristics of the working equipment and is set in the control system when setting it up. Thus, the task of ensuring optimal pressure force in the process of digging is solved.

Guaranteed exclusion of the critical mode at the initial stage of digging allows you to rationally distribute the load on the turntable of the excavator. Namely, the hoist winch and swing drives are transferred to the rear half of the central part of the turntable. Moreover, the installation of a hoist winch with a maximum approximation to the rear end of the turntable and the placement of the rotation drives between the rear beams of the biped can significantly reduce the weight of the counterweight needed to balance the turntable and ensure the stability of the excavator. In addition, the placement of the rotation drives between the rear beams of the two-leg strut above the rear of the roller circle, while tilting the turntable forward, during digging, eliminates additional radial loads on the drive gear, since in this case the radial clearance in the gearing of the rotation mechanism increases. This placement of equipment on a turntable is new, allows you to rationally distribute the load on it and solves the problem.

Figure 1 presents a General view of the excavator that implements the management of excavation.

Figure 2 presents the turntable of the excavator, top view.

Figures 1 and 2 show an excavator comprising a running carriage 1, on the upper belt of which a roller circle 2 is mounted, a rotary platform 3 is mounted on it. On the rotary platform 3 there is a body 4 with drives and turning mechanisms 5 of a lift 6, as well as a control system electric drives 7. In addition, on the turntable 3 are installed: two-legged strut 8, consisting of two struts - front 9 and rear 10, each of which is made in the form of two beams, an arrow 11, on which a handle 13 with a bucket is mounted in the saddle bearing 12 14. On the arrow 11, a sensor 15 is installed in the mounting area of the saddle bearing, which fixes the angle of rotation of the saddle bearing 12 relative to the vertical and is connected with the electric drive control system 7. The reciprocating movement of the handle 13 with the bucket 14 relative to the saddle bearing 12 is carried out by the pressure mechanism 16 located on the boom 11. The arrow 11 is fixed by cables 17 relative to the two-legged rack 8. Lifting ropes 18.

установленной расчетно- эмпирически в заданной системе управления электроприводами 7, как ограничительная (стопорная) для усилия напора.The method of managing excavation is as follows. At the beginning of digging, the bucket 14 is set into the face, then the drives and lifting mechanisms 6 and pressure 16 are moved along the bottom face until the bucket 14 is filled, followed by the excavator turning to unload and back to the face. At the beginning of digging, at the time of casting the bucket 14 to the tracks of the undercarriage 1, the reaction from the drive force of the pressure head 16 in combination with the resultant of the forces in the branches of the hoisting ropes 18 creates a state of unstable equilibrium. An unstable equilibrium can overturn the boom 11 in the direction of the biped 8 and is realized provided that the angle formed by the handle 13 and the vertical ≤6 °, which is equivalent to the angle of rotation of the saddle bearing 12. The actual position of the saddle bearing 12, and therefore, the handle 13 determines the angle sensor rotation of the saddle bearing 15 and provided that the angle of the saddle bearing and the vertical ≤6 °, sends a signal to the drive control system 7, which limits the pressure acting on the handle to a value equal to

established calculation and empirically in a given control system of electric drives 7, as restrictive (stop) for the pressure force.

The application of the invention allows you to create the optimal pressure head force at the beginning of digging, while eliminating contingencies when under the influence of the pressure head the boom can be cast and the equipment layout on the turntable can be changed qualitatively due to the possibility of a new load distribution on it.

The ability to transfer heavy units to the rear of the turntable significantly reduces the weight of the counterweight, which is used to balance the turntable and ensure the stability of the entire excavator as a whole. Reducing the weight of the counterweight in turn reduces the load on the roller wheel and the mass of the excavator, which determines the decrease in specific pressure on the soil and, as a result, the ability to use the excavator on weaker soils, which expands its technological capabilities.

Claims (2)

1. The method of controlling the excavation of the soil by installing the bucket in the bottom, moving it with pressure and lift drives until filling, turning from the bottom and unloading, characterized in that at the initial stage of digging, the angle of rotation of the saddle bearing with the handle and the vertical is continuously monitored, at angle values ≤6 ° the pressure force is reduced to a value determined by the formula:

where S _n - pressure force;
S _n is the lifting force realized at the beginning of digging;
R _c l _c - reaction in the arrow from the handle and the shoulder of its action;
G _i - the weights of the nodes on the boom (metal, pressure head drive, platforms, head blocks, electric motor);
l _i - the shoulder action of the corresponding weight relative to the axis of attachment of the boom to the turntable;
k is the safety margin of the boom specified during design at the time of digging;
l _ln - the shoulder action of the lifting force (S _n ), implemented at the beginning of digging relative to the axis of attachment of the boom in the rope going from the head units to the bucket;
l _2n is the shoulder of the action of the lifting force (S _n ), which is realized at the beginning of digging relative to the axis of attachment of the boom in the rope going from the head blocks to the drum of the lifting winch;
l _n - the shoulder action of the pressure force (S _n ). 2. An excavator for implementing the method according to claim 1, comprising a running trolley with a roller circle on which a turntable is mounted with a body, a cab, drives, swing and hoist mechanisms, an electric drive control system, a two-leg rack, made in the form of a front and rear two-beam structures, working equipment, including an arrow, a bucket with a handle mounted in a saddle bearing;
a saddle bearing, a pressure reducer with a gear wheel and an electric motor are located on an arrow connected by cables to a two-legged stand, characterized in that a saddle bearing angle sensor connected to the drive control system is mounted on the arrow in the area of the saddle bearing, the lifting mechanism is located as close as possible to the rear end of the turntable, and the drives and swing mechanisms are located between the rear beams of the biped rack above the roller circle.

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