Electric shovel lifting steel wire rope loosening and breaking detection device and control method

Abstract

The invention discloses an electric shovel lifting steel wire rope loosening and breaking detection device and a control method, and relates to the technical field of electric shovels, and the electric shovel lifting steel wire rope loosening and breaking detection device comprises a winding drum position detection device, a head sheave position detection device and a control unit. According to the electric shovel lifting steel wire rope loosening and breaking detection device and the control method, integration of data processing, state judgment, motor control and alarm is achieved through the control unit, manual intervention is not needed, and the defect that in the prior art, response is not timely due to the fact that manual observation depends on a driver is overcome. Differentiated control strategies are adopted according to different steel wire rope states, the motor speed is limited in the loose state, shutdown and brake contracting are immediately conducted in the broken state, impact damage of the steel wire rope from loosening to tightening is effectively avoided, and the steel wire rope, a bucket and the mechanical structure of whole electric shovel equipment are protected.

Description

Technical Field

[0001] This application belongs to the field of electric shovel technology, and in particular relates to a device and control method for detecting and controlling the slack and breakage of the lifting wire rope of an electric shovel. Background Technology

[0002] An electric shovel (full name: mining machinery front shovel excavator) is an electrically driven mechanical device, such as... Figure 1 As shown, it is mainly used for ore mining and rock stripping in open-pit mines. A work cycle consists of several processes, including digging, full bucket rotation and unloading, and empty bucket rotation to the excavation site.

[0003] During loading, the lifting mechanism drives the bucket to lift, while the push shaft pushes the bucket handle towards the working face. The two mechanisms work together to excavate material. When the bucket is lifted, the lifting motor rotates forward, driving the lifting drum. The wire rope is taut and, supported by the sheave, pulls the bucket upward, while the sheave rotates forward synchronously. When the bucket is lowered, the lifting motor reverses, and under the combined action of the motor and the bucket's own weight, the lifting drum reverses, the wire rope is taut, controlling the bucket's descent, and the sheave rotates backward synchronously. During the bucket's descent, if it encounters minerals or the ground, and the lifting motor does not stop or slow down in time, the lifting wire rope will slack, causing the drum wire rope to jump or overlap. When the motor rotates at high speed, the wire rope transitions from a slack to a taut state, impacting the wire rope, bucket, and the entire equipment, potentially damaging the wire rope and other mechanical structures, and jeopardizing the safe operation of the electric shovel.

[0004] Current electric shovels mainly rely on the driver to monitor whether the wire rope is slack or broken through camera footage. There are no sensors to monitor the slack of the lifting wire rope, making it difficult for the driver to take timely action when a malfunction occurs. Summary of the Invention

[0005] To address some or all of the technical problems existing in the prior art, this application provides a detection device and control method for slack and breakage of electric shovel lifting wire rope.

[0006] This application provides a device for detecting slack and breakage of a lifting wire rope in an electric shovel, including a drum position detection device, a sheave position detection device, and a control unit. The drum position detection device is installed on the central shaft of the lifting drum of the electric shovel and is used to collect the rotational state information of the lifting drum. The sheave position detection device is installed on the central shaft of the sheave of the electric shovel and is used to collect the rotational state information of the sheave. The control unit is electrically connected to the drum position detection device, the sheave position detection device, and the lifting motor of the electric shovel, and is used to receive the information collected by the drum position detection device and the sheave position detection device, perform data processing and state judgment, and send control commands to the lifting motor.

[0007] This application also provides a method for controlling the slack and breakage of the wire rope used in electric shovel hoisting, including the following steps: S1. During electric shovel operation, the drum position detection device and the sheave position detection device synchronously collect the rotation status information of the hoisting drum and the sheave, and transmit the collected information to the control unit in real time. S2. Based on the received rotation status information, the control unit calculates the absolute length of the wire rope corresponding to the hoisting drum and the absolute length of the wire rope corresponding to the sheave, and further calculates the length difference between the two. S3. The control unit compares the calculated length difference with the preset value under normal tension to determine the current state of the lifting wire rope. S4. Based on the judgment result, the control unit sends the corresponding control command to the hoisting motor and triggers an alarm reminder at the same time; if it is in a normal state, it controls the hoisting motor to run normally; if it is in a slack state, it limits the lowering speed and hoisting speed of the hoisting motor; if it is in a broken or detached state, it controls the hoisting motor to stop running immediately and applies the brake.

[0008] The electric shovel hoisting wire rope slack and breakage detection and control method of this application has the following advantages and positive effects: (1) An absolute encoder is used as a position detection device. The installation method is simple. The design of coaxial connection with the central shaft can directly obtain the core rotation data. The acquisition accuracy is high and the anti-interference ability is strong.

[0009] (2) The control unit integrates data processing, status judgment, motor control and alarm without manual intervention, which solves the problem of untimely response caused by the reliance on driver manual observation in the existing technology.

[0010] (3) Differentiated control strategies are adopted for different wire rope states. The motor speed is limited in the slack state and the machine is stopped and braked immediately in the breakage state. This effectively avoids the impact damage of the wire rope from slack to taut and protects the wire rope, bucket and the mechanical structure of the entire electric shovel. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for further understanding of the embodiments of this application and constitute a part of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the structure of an electric shovel device in the prior art; Figure 2This is a schematic diagram showing the installation positions of the drum position detection device and the sheave position detection device of this application; Figure 3 This is the control logic diagram of the lifting motor in this application.

[0012] Explanation of reference numerals in the attached figures: 1-Lifting drum, 2-Head sheave, 3-Wire rope, 4-Drum position detection device, 5-Head sheave position detection device. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0014] like Figure 2 As shown, the slack and breakage detection device for the electric shovel lifting wire rope 3 in this embodiment includes a drum position detection device 4, a sheave position detection device 5, and a control unit. The drum position detection device 4 is installed on the central shaft of the lifting drum 1 of the electric shovel and is used to collect the rotational state information of the lifting drum 1. The sheave position detection device 5 is installed on the central shaft of the sheave 2 of the electric shovel and is used to collect the rotational state information of the sheave 2. The control unit is electrically connected to the drum position detection device 4, the sheave position detection device 5, and the lifting motor of the electric shovel, respectively, and is used to receive the information collected by the drum position detection device 4 and the sheave position detection device 5, perform data processing and state judgment, and send control commands to the lifting motor.

[0015] Preferably, both the drum position detection device 4 and the sheave position detection device 5 are absolute encoders. Their housings are made of high-strength wear-resistant material, which can resist dust erosion and mechanical vibration in the mining operation environment. The internal coding structure can convert the mechanical rotation of the drum or sheave 2 into an electrical signal.

[0016] The drum position detection device 4 can be fixedly installed at the end of the central shaft of the lifting drum 1 by bolts. When the lifting drum 1 rotates, the drum position detection device 4 rotates synchronously with the central shaft of the lifting drum 1, and collects the rotation angle and number of turns of the drum in real time. This information serves as the basic data reflecting the change in the length of the wire rope 3 on the drum side, and can accurately reflect the winding and unwinding state of the wire rope 3.

[0017] The sheave position detection device 5 can be fixedly installed at the end of the central shaft of the sheave 2 with bolts and rotates coaxially with the central shaft of the sheave 2. When the wire rope 3 drives the sheave 2 to rotate, the sheave position detection device 5 synchronously collects the rotation angle and number of turns of the sheave 2 as key data for the change in the length of the wire rope 3 on the side of the sheave 2, and forms a corresponding relationship with the data collected by the drum position detection device 4.

[0018] The control unit is installed in the electrical control box of the electric shovel. The processor inside the control unit has fast computing and data processing capabilities. It can receive electrical signals transmitted by the two encoders in real time and convert them into corresponding length information. The control unit can also send control commands such as speed adjustment, shutdown, and brake to the hoisting motor based on the processor's judgment results. At the same time, it can issue alarm reminders through the audible and visual alarm device in the electric shovel cab.

[0019] Preferably, shielded cables can be used for data transmission between the control unit and the drum position detection device 4 and the sheave position detection device 5. Shielded cables can effectively resist electromagnetic interference in the mining operation environment, ensure the integrity and accuracy of the transmitted data, and provide a reliable basis for subsequent calculation and analysis.

[0020] like Figure 2 and Figure 3 As shown, the method for controlling slack and breakage of the electric shovel lifting wire rope in this embodiment includes the following steps: S1. When the electric shovel is in operation, the drum position detection device 4 and the sheave position detection device 5 synchronously collect the rotation status information of the hoisting drum 1 and the sheave 2, and transmit the collected information to the control unit in real time. S2. Based on the received rotation status information, the control unit calculates the absolute length of the wire rope 3 corresponding to the hoisting drum 1 and the absolute length of the wire rope 3 corresponding to the sheave 2, and further calculates the length difference between the two. S3. The control unit compares the calculated length difference with the preset value under normal tension to determine the current state of the lifting wire rope 3. S4. Based on the judgment result, the control unit sends the corresponding control command to the hoisting motor and triggers an alarm reminder at the same time; if it is in a normal state, it controls the hoisting motor to run normally; if it is in a slack state, it limits the lowering speed and hoisting speed of the hoisting motor; if it is in a broken or detached state, it controls the hoisting motor to stop running immediately and applies the brake.

[0021] When the electric shovel is working normally, the main structures related to the wire rope 3 include the lifting drum 1, the sheave 2, and the bucket. The lifting drum 1 and the sheave 2 have rope grooves. Under the influence of the bucket's gravity, the wire rope 3 remains taut, preventing overlap or skipping of the grooves. The lifting drum 1 is equipped with a drum position detection device 4 (such as an absolute encoder), which provides the encoder value 'a'. A sheave position detection device 5 (such as an absolute encoder) is installed on the central shaft of the sheave 2, providing the encoder value 'b'.

[0022] Assume that the values ​​of both encoders increase along the direction below the wire rope 3, the pulse count of the drum encoder is m1, the radius of the drum is r1, and the absolute length T1 represented by the drum encoder is... The pulse count of the sheave 2 encoder is m2, the encoder value of sheave 2 is r2, and the absolute length T2 represented by the sheave 2 encoder is... Calculate using the following formula: ; ; ; in, T represents the difference in absolute length of the wire rope 3 between the hoisting drum 1 and the sheave 2. When the wire rope 3 is taut, the hoisting drum 1 and the sheave 2 rotate synchronously, so their angular velocities at their maximum radii are the same, and the absolute lengths of the changes in T1 and T2 are the same. Therefore, under the normal tension of the wire rope 3... T should be a constant value α.

[0023] like Figure 3 As shown, during the excavation process, if T=α indicates that wire rope 3 is taut and the motor can operate normally. If If T < α, it indicates that wire rope 3 has detached or broken. In this case, the motor will be stopped immediately and the brake will be applied to prevent further damage to wire rope 3. An alarm will also be triggered to alert the driver to the condition of wire rope 3. If If T > α, it indicates that the wire rope 3 has become slack. The lowering speed of the motor will be limited to prevent the wire rope 3 from falling off further. At the same time, the lifting speed of the motor will be limited until the wire rope 3 is detected to be taut to prevent the wire rope 3 from becoming tangled or impacted due to excessive lifting speed. An alarm will also be triggered to remind the driver to pay attention to the condition of the wire rope 3.

[0024] The specific operating procedure is as follows: Once the electric shovel is started and in operation, the drum position detection device 4 and the sheave position detection device 5 begin working synchronously, continuously collecting rotational status information of the hoisting drum 1 and the sheave 2, and transmitting the collected electrical signals to the control unit in real time via shielded cables. After receiving the signals, the control unit's processor analyzes the rotational information transmitted by the two devices, calculates the absolute length of the wire rope 3 corresponding to the drum rotation, and the absolute length of the wire rope 3 corresponding to the sheave 2 rotation, and then calculates the difference between these two lengths.

[0025] The control unit has a pre-stored set value for the length difference of the lifting wire rope 3 under normal tension. The processor compares the real-time calculated length difference with this set value to determine the current state of the wire rope 3. If the real-time length difference is consistent with the preset value, it means that the lifting wire rope 3 is under normal tension. The control unit then sends a normal operation command to the lifting motor, and the electric shovel continues to work according to the preset operation procedure, without triggering the alarm device.

[0026] If the real-time length difference is greater than the preset value, it indicates that the lifting wire rope 3 has become slack. At this time, the control unit immediately sends a speed limit command to the lifting motor to limit the motor's lowering speed and prevent the wire rope 3 from becoming slack and causing it to jump off the track or overlap. At the same time, before the wire rope 3 is detected to return to a taut state, the lifting speed of the motor is continuously limited to prevent the wire rope 3 from suddenly becoming taut due to excessively fast lifting and causing an impact. Meanwhile, the control unit triggers the audible and visual alarm device in the cab to remind the driver to pay attention to the status of the wire rope 3 and to promptly investigate the cause of the slack.

[0027] If the real-time length difference is less than the preset value, it indicates that the lifting wire rope 3 may have broken or fallen off. The control unit will quickly send a stop operation command to the lifting motor and control the brake device to brake in time to prevent further damage to the wire rope 3 and avoid dangers such as the bucket falling due to loss of traction. At the same time, the audible and visual alarm device will continuously emit a strong alarm signal to warn the driver to take emergency measures immediately.

[0028] It should be noted that, unless otherwise expressly specified and limited, the term "connection" or its synonyms should be interpreted broadly in this document. For example, "connection" can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, expressions such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. At the same time, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In addition, the terms "front," "rear," "left," "right," "upper," and "lower" in this document refer to the placement states shown in the accompanying drawings.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A device for detecting slack and breakage of a wire rope used in electric shovel hoisting, characterized in that, The device includes a drum position detection device (4), a sheave position detection device (5), and a control unit. The drum position detection device (4) is installed on the central shaft of the lifting drum (1) of the electric shovel and is used to collect the rotation status information of the lifting drum (1). The sheave position detection device (5) is installed on the central shaft of the sheave (2) of the electric shovel and is used to collect the rotation status information of the sheave (2). The control unit is electrically connected to the drum position detection device (4), the sheave position detection device (5), and the lifting motor of the electric shovel, respectively, and is used to receive the information collected by the drum position detection device (4) and the sheave position detection device (5), perform data processing and status judgment, and send control commands to the lifting motor.

2. A method for controlling slack and breakage of a lifting wire rope in an electric shovel, characterized in that, The detection device according to claim 1 includes the following steps: S1. When the electric shovel is in operation, the drum position detection device (4) and the sheave position detection device (5) synchronously collect the rotation status information of the lifting drum (1) and the sheave (2), and transmit the collected information to the control unit in real time. S2. The control unit calculates the absolute length of the wire rope (3) corresponding to the hoisting drum (1) and the absolute length of the wire rope (3) corresponding to the sheave (2) based on the received rotation status information, and further calculates the length difference between the two. S3. The control unit compares the calculated length difference with the preset value under normal tension to determine the current state of the lifting wire rope (3). S4. Based on the judgment result, the control unit sends the corresponding control command to the hoisting motor and triggers an alarm reminder at the same time; if it is in a normal state, it controls the hoisting motor to run normally; if it is in a slack state, it limits the lowering speed and hoisting speed of the hoisting motor; if it is in a broken or detached state, it controls the hoisting motor to stop running immediately and applies the brake.

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