Braking method of downward belt conveyor, computer equipment and storage medium

Abstract

The invention belongs to the technical field of intelligent belt conveyors, discloses a braking method for a downward belt conveyor, computer equipment and a storage medium, and aims to realize accurate application of braking torque, guarantee safe and reliable braking and stopping of the downward belt conveyor and avoid mechanical impact and electrical impact on the belt conveyor. The braking method of the downward conveying belt conveyor serves as an important component of the intelligent belt conveyor, is applied to the downward conveying belt conveyor and can accurately judge the magnitude of the braking torque needed by the belt conveyor during emergency stop braking, so that the real-time braking torque is matched with the theoretical braking torque, accurate application of the braking torque is achieved, and the braking efficiency of the belt conveyor is improved. By means of the braking device, safe and reliable braking and stopping of the downward conveying belt conveyor are guaranteed, when a main motor is cut off in emergency stopping, mechanical impact and electrical impact on the belt conveyor caused by too large braking torque are avoided, the galloping accident caused by too small braking torque is also avoided, and therefore the operation and maintenance cost of the downward conveying belt conveyor is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent belt conveyors, and particularly relates to a braking method for a downward belt conveyor, a computer device, and a storage medium. Background Art

[0002] As an important bulk material conveying equipment, belt conveyors have been significantly developed in industries such as coal mines, mines, docks, cement, steel, and metallurgy. With the universality of their applications, belt conveyors are developing in the directions of long distance, large conveying capacity, and high power. The starting mode of current belt conveyors realizes soft start and soft stop functions by the cooperation of frequency converters and main motors, and the braking mode mainly adopts a normally closed disc braking device with hydraulic opening and disc spring braking as the main configuration form. For horizontal or upward belt conveyors, the control logic for controlling the braking and stopping of belt conveyors is relatively mature: (1) During the normal braking and stopping process, by changing the output frequency of the frequency converter, the speed of the main motor is reduced, and then the speed of the conveyor is adjusted. After the conveyor speed is reduced to a certain value, the disc braking device is controlled to brake and stop the vehicle; (2) When emergency braking and stopping are required, by changing the output frequency of the frequency converter and cooperating with the disc braking device, the rapid stop of the conveyor is realized to avoid the expansion of accidents. There is no occurrence of "runaway" accidents in horizontal and upward belt conveyors.

[0003] Due to various factors such as the layout conditions, transportation working conditions, production needs, and terrain of belt conveyors, downward belt conveyors need to be designed and used. Downward belt conveyors have various working conditions such as no-load, light-load, and heavy-load in actual operation. Since belt conveyors are large inertia load devices, when emergency braking and stopping are performed under the above three working conditions, excessive application of braking torque will cause impacts on mechanical equipment such as the belt and frame of the belt conveyor, and at the same time will cause shortening or damage to the service life of electrical equipment such as frequency converters and main motors; when the applied braking torque is too small, "runaway" accidents will occur, resulting in serious production accidents. The magnitude of the braking torque required when the downward belt conveyor stops changes with the amount of material on the belt. The existing belt conveyor control system cannot accurately judge the magnitude of the braking torque required during emergency stop braking, and even less can realize the application of precise braking torque. The existing control system mainly considers safety factors for reliable stopping when applying braking force, without comprehensively considering various factors such as precision, reliability, safety, and cost reduction. Summary of the Invention

[0004] The object of the present invention is to propose a braking method for a downward belt conveyor to achieve precise application of braking torque, ensure safe and reliable braking and stopping of the downward belt conveyor, and avoid mechanical and electrical impacts on the belt conveyor.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A braking method for a downward belt conveyor. The belt conveyor includes a main motor, a reducer, a drum, a conveyor belt, a brake disc, and a brake. The main motor is connected to the drum through the reducer. The drum is drivingly connected to the conveyor belt. The brake disc is connected to the drum. The brake can act on the brake disc.

[0007] An encoder is provided on the main motor, a torque sensor is provided on the main motor and / or the reducer, and a pressure sensor is provided on the brake disc and / or the brake.

[0008] The encoder monitors the rotational speed n of the main motor in real time; the torque sensor monitors the torque in real time and calculates the theoretical braking torque T required for the conveyor belt. 制动器 and further calculates the target normal pressure N of the brake acting on the brake disc. e The pressure sensor monitors the normal pressure N between the brake disc and the brake in real time.

[0009] The method includes the following steps:

[0010] S1. Determine whether the main motor is in a generating condition according to the rotational speed n of the main motor. When the main motor is in a generating condition, at the same time, change the normal pressure N between the brake disc and the brake so that N = N. e ;

[0011] Wherein, before S1 or during S1, make N = N. e After that, the main motor is powered off.

[0012] S2. Change the normal pressure N between the brake disc and the brake so that the conveyor belt decelerates at a set deceleration until braking to a stop.

[0013] Based on the above braking method for a downward belt conveyor, the present invention also proposes a computer device. The computer device includes a memory and one or more processors. An executable code is stored in the memory. When the processor executes the executable code, it is used to implement the above-mentioned braking method for a downward belt conveyor.

[0014] Based on the above braking method for a downward belt conveyor, the present invention also proposes a computer-readable storage medium, on which a program is stored; when the program is executed by a processor, it is used to implement the above-mentioned braking method for a downward belt conveyor.

[0015] The present invention has the following advantages:

[0016] As an important part of the intelligent belt conveyor, the present invention is applied to the down - conveyor belt conveyor, which can accurately judge the magnitude of the braking torque required by the belt conveyor during emergency stop braking, make the real - time braking torque match the theoretical braking torque, achieve accurate application of the braking torque, ensure the safe and reliable braking and stopping of the down - conveyor belt conveyor. When the main motor is cut off during emergency stop, it can avoid the mechanical and electrical impacts on the belt conveyor caused by excessive braking torque, and also avoid the "runaway" accident caused by too small braking torque, thereby reducing the operation and maintenance costs of the down - conveyor belt conveyor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flowchart of the braking method for the down - conveyor belt conveyor in an embodiment of the present invention;

[0018] Figure 2 It is a schematic structural diagram of the driving and braking part of the belt conveyor in an embodiment of the present invention;

[0019] Figure 3 It is an arrangement diagram of sensors for the brake disc and brake caliper parts in an embodiment of the present invention;

[0020] Description of the reference numerals:

[0021] 11, main motor; 12, reducer; 21, driving drum; 22, redirecting drum; 23, conveyor belt; 31, brake disc; 32, brake caliper; 33, coupling; 41, encoder; 42, torque sensor; 43, pressure sensor; 44, displacement sensor; 45, belt speed sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments:

[0023] Embodiment 1

[0024] As Figures 1 to 3 shown, in this embodiment, a braking method for a down - conveyor belt conveyor is proposed. The belt conveyor includes a main motor 11, a reducer 12, drums (driving drum 21 and redirecting drum 22), a conveyor belt 23, a brake disc 31 and a brake caliper 32. The main motor 11 is connected to the drum through the reducer 12, the drum is drivingly connected to the conveyor belt 23, the brake disc 31 is connected to the drum, and the brake caliper 32 can act on the brake disc 31. Among them, the drum includes a driving drum 21 and a redirecting drum 22. The output end of the main motor 11 is connected to the input end of the reducer 12, the output end of the reducer 12 is connected to the driving drum 21, and the brake disc 31 is connected to the redirecting drum 22 through a coupling 33.

[0025] An encoder 41 is provided at the tail end of the main motor 11, a torque sensor 42 is provided between the output end of the main motor 11 and the input end of the speed reducer 12, a pressure sensor 43 is provided inside the brake 32, a displacement sensor 44 is provided on the brake 32, and a belt speed sensor 45 is provided on one side of the conveyor belt 23.

[0026] The control unit is set as a PLC controller. The PLC controller is respectively connected to the control end of the main motor 11, the control end of the brake 32, the encoder 41, the torque sensor 42, the pressure sensor 43, the displacement sensor 44 and the belt speed sensor 45 via signal cables. The control unit realizes the acquisition of data from each sensor, and processes the acquired data and participates in the control logic.

[0027] The control unit is powered by a UPS power supply. The control unit can work normally under any circumstances, realizing the normal output of sensor data acquisition and control instructions.

[0028] The encoder 41 monitors the rotational speed n of the main motor 11 in real time and uploads it to the PLC controller; the torque sensor 42 monitors the torque in real time and uploads it to the PLC controller, and the PLC controller calculates the theoretical braking torque T required for the conveyor belt 23 制动器 and further calculates the target normal pressure N exerted by the brake 32 on the brake disc 31 e .

[0029] The formula for obtaining the theoretical braking torque T required for the conveyor belt is as follows: 制动器 :

[0030] T 制动器 = t × i 减速比 ;

[0031] where,

[0032] t is the real-time torque monitored by the torque sensor at the output end of the main motor; i 减速比 is the reduction ratio of the speed reducer.

[0033] The formula for calculating the braking target normal pressure N e is as follows:

[0034] N e = T 制动器 u·z·r;

[0035] where,

[0036] N e is the braking target normal pressure; u is the friction coefficient between the friction plate of the brake and the brake disc; z is the number of brake pairs acting on the brake disc; r is the effective radius from the center of the brake to the center of the brake disc.

[0037] The pressure sensor 43 monitors the normal pressure N between the brake disc 31 and the brake caliper 32 in real time and uploads it to the PLC controller.

[0038] The displacement sensor 44 monitors the opening gap between the brake disc 31 and the brake caliper 32 in real time and uploads it to the PLC controller.

[0039] The belt speed sensor 45 monitors the speed of the conveyor belt 23 in real time and uploads it to the PLC controller.

[0040] The brake disc 31 and the brake caliper 32 are part of a disc brake device, and the disc brake device also includes a controllable hydraulic station and a brake hydraulic system.

[0041] The brake caliper 32 of the disc brake device operates in a hydraulic opening and disc spring closing manner, and is in a closed state when the disc brake device is not working. The braking torque of the disc brake device is generated by the frictional force between the brake caliper 32 and the brake disc 31. Therefore, adjusting the normal pressure N of the brake caliper 32 on the brake disc 31 can change the braking torque. When the belt conveyor is running normally, the oil pressure of the brake hydraulic system reaches the maximum value. At this time, the normal pressure N is 0, and there is a gap of 1 - 1.5 mm between the brake caliper 32 and the brake disc 31, that is, the brake caliper 32 is in an open state. When the belt conveyor needs to be braked, the control unit issues a control command according to the working conditions, so that the disc brake device automatically reduces the oil pressure according to a predetermined program to meet the braking requirements. Since the deformation of the disc spring is generated by the pushing of the brake cylinder inside the brake caliper 32, the magnitude of the braking force of the brake caliper 32 is the difference between the thrust generated by the disc spring and the oil pressure inside the internal brake cylinder. The brake caliper 32 is normally closed, so that the magnitude of the normal pressure N can be controlled by controlling the magnitude of the oil pressure inside the brake cylinder. When the oil pressure inside the brake cylinder increases, the normal pressure N decreases, and when the oil pressure inside the brake cylinder decreases, the normal pressure N increases. Therefore, setting a pressure sensor 43 inside the brake caliper 32 can achieve accurate detection of the braking force.

[0042] A displacement sensor 44 is set on the brake caliper 32. The displacement sensor 44 monitors the opening gap between the brake disc 31 and the brake caliper 32 in real time, judges the wear amount of the brake shoe of the brake caliper 32, and ensures the normal use of the brake caliper 32. The displacement sensor 44 can not only monitor the opening gap, but also judge whether the wear of the brake shoe of the brake caliper 32 exceeds the limit according to the displacement difference between opening and closing. Excessive wear of the brake shoe will cause too large an opening gap. Therefore, the brake shoe of the brake caliper 32 needs to be manually adjusted to avoid insufficient braking force during braking due to too large an opening gap. In addition, an oil pressure sensor is set in the brake hydraulic system, and the opening gap is monitored by the oil pressure sensor and the displacement sensor 44 at the same time. After comparing the oil pressure parameters detected by the oil pressure sensor with the displacement parameters detected by the displacement sensor 44, it is judged whether there is a jamming phenomenon during the opening or closing process of the brake caliper 32.

[0043] In the braking hydraulic system, by controlling the change of the working current of the proportional electromagnet on the proportional valve, the opening degree of the proportional valve is controlled to change the oil pressure in the brake cylinder inside the brake 32, and further to realize the opening and closing of the brake 32 and change the magnitude of the normal pressure N exerted by the brake 32 on the brake disc 31.

[0044] The method includes the following steps:

[0045] S1. Determine whether the main motor 11 is in the power generation condition according to the rotation speed n of the main motor 11. When the rotation speed n of the main motor 11 is greater than the synchronous rotation speed n e of the main motor, the main motor 11 is in the power generation condition;

[0046] n e = 60f / p;

[0047] where,

[0048] f is the power supply frequency of the main motor; p is the number of pole pairs of the main motor.

[0049] When the main motor 11 is in the power generation condition, at this time, the main motor 11 generates a braking force, and the downward component force of the material on the conveyor belt 23 is greater than the downward running resistance of the conveyor belt 23. When the belt conveyor runs at a constant speed, the sum of the braking force generated by the main motor 11 and the resistance on the conveyor belt 23 reaches a dynamic balance with the downward component force of the material on the conveyor belt 23. When the material on the conveyor belt 23 changes, the braking force generated by the main motor 11 is also automatically adjusted accordingly; when the rotation speed n of the main motor 11 is less than the synchronous rotation speed n e of the main motor 11, the main motor 11 is in the electric working condition.

[0050] When the main motor 11 is in the power generation condition, at the same time, change the normal pressure N between the brake disc 31 and the brake 32 so that N = N e ;

[0051] where, before S1 or during S1, make N = N e and then, the main motor 11 is powered off;

[0052] When the main motor 11 is powered off before S1, the corresponding working condition is the "power-off instruction" issued by the control unit during emergency shutdown. At this time, due to a serious electrical fault or serious overload operation of the belt conveyor, the main motor 11 suddenly loses power, and the feedback braking torque generated by the main motor 11 disappears instantly.

[0053] When the main motor 11 is powered off after making N = N e during S1, the corresponding working condition is the "emergency stop instruction" issued by the control unit during emergency shutdown. At this time, the main motor 11 inverter actively cuts off the power, and the feedback braking torque generated by the main motor 11 disappears.

[0054] S2. Change the normal pressure N between the brake disc 31 and the brake 32, monitor the speed of the conveyor belt 23 in real time according to the belt speed sensor 45, change the oil pressure of the brake cylinder, and decelerate the conveyor belt at a set deceleration rate (such as at a deceleration rate of 0.1 m / s 2 to 0.3 m / s 2 ), to avoid the conveyor belt 23 from slipping on the driving roller 21, causing damage to the conveyor belt 23 or the material on the conveyor belt 23 to slide and pile up due to too fast deceleration. When the speed of the conveyor belt 23 is less than 0.5 m / s, the rapid braking and shutdown is completed.

[0055] Embodiment 2

[0056] This Embodiment 2 relates to a computer device, which includes a memory and one or more processors. Executable code is stored in the memory. When the processor executes the executable code, it is used to implement the steps of the braking method of the downward conveyor belt in Embodiment 1 as described above.

[0057] Embodiment 3

[0058] This Embodiment 3 relates to a computer-readable storage medium, on which a program is stored. When the program is executed by a processor, it is used to implement the steps of the braking method of the downward conveyor belt in Embodiment 1 as described above.

[0059] The computer-readable storage medium can be an internal storage unit of any device or apparatus with data processing capabilities, such as a hard disk or memory, or an external storage device of any device with data processing capabilities, such as a plug-in hard disk, a Smart Media Card (SMC), an SD card, a Flash Card, etc. equipped on the device.

[0060] So far, this embodiment has been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the present invention. Of course, the above description is only the preferred embodiment of the present invention, and the present invention is not limited to listing the above embodiments. It should be noted that all equivalent substitutions and obvious deformation forms made by any person skilled in the art under the teaching of this specification fall within the substantial scope of this specification and should be protected by the present invention.

Claims

1. A braking method for a downward belt conveyor, characterized in that the belt conveyor includes a main motor, a reducer, a drum, a conveyor belt, a brake disc and a brake. The main motor is connected to the drum through the reducer. The drum is drivingly connected to the conveyor belt. The brake disc is connected to the drum. The brake can act on the brake disc; an encoder is provided on the main motor, a torque sensor is provided on the main motor and / or the reducer, and a pressure sensor is provided on the brake disc and / or the brake; The encoder monitors the rotational speed n of the main motor in real time; the torque sensor monitors the torque in real time and calculates the theoretical braking torque T required for the conveyor belt 制动器 , and further calculates the target normal pressure N exerted by the brake on the brake disc e ; the pressure sensor monitors the normal pressure N between the brake disc and the brake in real time The method includes the following steps: S1. Determine whether the main motor is in the power generation mode based on the rotational speed n of the main motor. When the main motor is in the power generation mode, at the same time, change the normal pressure N between the brake disc and the brake caliper so that N = N e ; Wherein, before S1 or during S1, make N = N e After that, the main motor is powered off; S2. Change the normal pressure N between the brake disc and the brake so that the conveyor belt decelerates at a set deceleration until braking stops.

2. The braking method for a downward belt conveyor according to claim 1, characterized in that a torque sensor is provided between the output end of the main motor and the input end of the reducer; Obtain the theoretical braking torque T required for the conveyor belt 制动器 The formula is as follows: T 制动器 = t × i 减速比 ; wherein, t is the real-time torque at the output end of the main motor monitored by the torque sensor; i 减速比 is the reduction ratio of the speed reducer.

3. The braking method for a downward belt conveyor according to claim 1 or 2, characterized in that The calculated braking target normal pressure N e has the following formula: N e = T 制动器 u·z·r; wherein, N e where N is the target braking normal pressure; μ is the friction coefficient between the friction lining of the brake and the brake disc; z is the number of brake pairs acting on the brake disc; and r is the effective radius from the center of the brake to the center of the brake disc.

4. The braking method for a downward belt conveyor according to claim 1, characterized in that the drum includes a driving drum and a redirecting drum. The main motor is connected to the driving drum through the reducer, and the brake disc is connected to the redirecting drum.

5. The braking method for a downward belt conveyor according to claim 1, characterized in that the specific content of S1 is: When the rotational speed n of the main motor is greater than the synchronous rotational speed n of the main motor e the main motor operates in a power generation mode; n e = 60f / p; wherein, f is the power supply frequency of the main motor; p is the number of pole pairs of the main motor.

6. The braking method for a downward belt conveyor according to claim 1, characterized in that it further includes a belt speed sensor which monitors the speed of the conveyor belt in real time.

7. The braking method for a downward belt conveyor according to claim 1, characterized in that a displacement sensor is provided on the brake disc and / or the brake, and the displacement sensor monitors the opening gap between the brake and the brake disc in real time.

8. The braking method for a downward belt conveyor according to claim 1, characterized in that the belt conveyor further includes a control unit, and the control unit is respectively connected to the control end of the main motor, the control end of the brake, the encoder, the torque sensor and the pressure sensor by signals.

9. A computer device, comprising a memory and one or more processors, wherein executable code is stored in the memory, characterized in that, When the processor executes the executable code, it is used to implement the braking method for a downward belt conveyor according to any one of claims 1 to 8.

10. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed by the processor, it implements the braking method for a downward belt conveyor according to any one of claims 1 to 8.

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