Electrical limit control system and method for a coal belt plow unloader

Abstract

The application provides a coal injection belt plow unloader electrical limiting control system and method, which comprises a conversion module, a pressing control unit, a lifting control unit, a pressing limiting switch and a lifting limiting switch; the conversion module is connected with the input end of the pressing control unit through a first path and connected with the input end of the lifting control unit through a second path; the pressing limiting switch is connected with the enabling end of the pressing control unit; the lifting limiting switch is connected with the enabling end of the lifting control unit; when the conversion module is converted to the machine side position, the pressing control unit controls the motor to work, and when the plow blade is pressed to the position of the pressing limiting switch, the motor stops working; when the conversion module is converted to the position far away from the machine side, the lifting control unit controls the hydraulic push rod motor to work, and when the plow blade is lifted to the position of the lifting limiting switch, the motor stops working. Based on the system, the coal injection belt plow unloader electrical limiting control method is provided. The application realizes the matching of the mechanical stroke limiting switch and the plow unloader plow blade moving part.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, and specifically relates to an electrical limit control system and method for a pulverized coal belt plow unloader. Background Technology

[0002] The pulverized coal receiving and unloading conveyor belt system consists of five belts: K1, K4, M1, M2, and M3. Raw coal transported by train is moved to this conveyor belt via a tipper and stored in the raw coal yard. Two grab bucket cranes then grab the coal and feed it into 12 sets of raw coal silos. Following the wide-band feeders below the silos, the coal is fed into different raw material feeding conveyor belts according to the required proportions, ultimately reaching the corresponding raw coal silos for the pulverized coal system. The M3 conveyor belt is equipped with 25 sets of plow-type unloaders, corresponding to 25 loading positions in the raw coal yard, used to unload different types of raw coal into their respective positions. If the mechanical travel limit switch of the plow-type unloader malfunctions, causing the plow blades to fall too low, it will wear down the belt, potentially leading to belt tearing. Belt maintenance requires a considerable amount of time, affecting the normal operation of the tipper, accumulating train cars, and disrupting railway scheduling, making it difficult to rationally allocate transport capacity.

[0003] The existing limit switches for plow-type unloaders are mechanical travel limit switches, which have the following problems: 1. Mechanical travel limit switches require precise matching with the moving parts of the plow blades in the plow-type unloader, requiring repeated debugging, resulting in long installation and debugging times and low work efficiency. 2. During the descent of the plow-type unloader, due to inertia, the impact rod on the hydraulic push rod frequently overruns the ball bearing of the mechanical travel limit switch. There is no signal feedback from the machine-side control box, and the signal cannot be transmitted to the computer screen via PLC. Production workers need to confirm on-site before operating the equipment, which is inconvenient. 3. Replacing the hydraulic push rod of the plow-type unloader is generally done manually on-site. Because the electrical control circuit uses contactor self-holding, the mechanical hydraulic push rod cannot be precisely matched with the plow blades on the plow-type unloader. 4. High maintenance costs. The mechanical travel limit switch needs to collide with the impact rod of the hydraulic push rod to transmit signals. The component has many moving parts (mostly plastic products), resulting in a short service life and requiring regular maintenance after long-term use. 5. In terms of electrical control principles, mechanical travel limit switches have two pairs of contacts, resulting in multiple control circuits and making them prone to electrical circuit faults such as short circuits and grounding in the field. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes an electrical limit control system and method for a pulverized coal conveyor belt plow-type unloader. This solves the problem of requiring precise matching between the mechanical travel limit switch and the moving parts of the plow blade in the plow-type unloader.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An electrical limit control system for a pulverized coal belt plow unloader includes a conversion module, a pressing control unit, a lifting control unit, a pressing limit switch, and a lifting limit switch;

[0007] The conversion module has a first path connected to the input terminal of the pressing control unit via a wire, and a second path connected to the input terminal of the lifting control unit via a wire; the pressing limit switch is connected to the enable terminal of the pressing control unit; the lifting limit switch is connected to the enable terminal of the lifting control unit.

[0008] When the conversion module is converted to the machine-side position, the pressure control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader is pressed to the position of the pressure limit switch, the hydraulic push rod motor stops working. When the conversion module is converted to the position away from the machine-side position, the lifting control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader is lifted to the position of the lifting limit switch, the motor stops working.

[0009] Furthermore, the system also includes a remote control unit;

[0010] The remote control unit is connected to the input terminals of the pressing control unit and the lifting control unit via wires, and automatically controls the pressing control unit to perform pressing and lifting operations.

[0011] Furthermore, the system also includes a stop module; the stop module is connected in series with the conversion module;

[0012] The stop module is connected to the input terminals of the pressing control unit and the lifting control unit via wires, respectively, to stop the operation in time when a fault occurs during the pressing or lifting process.

[0013] Furthermore, the pressing control unit includes a pressing button, a normally closed contact of a pressing intermediate relay, and a pressing contactor connected in series.

[0014] When the pressing control unit performs the pressing operation, pressing the pressing button causes the hydraulic push rod motor to move the plow blade on the plow unloader to press into the pressing position sensing area. The normally closed contact of the pressing intermediate relay becomes a normally open contact, the pressing contactor is released, and the hydraulic push rod motor stops working.

[0015] Furthermore, the lifting control unit includes a lifting button, a normally closed contact of a lifting intermediate relay, and a lifting contactor connected in series.

[0016] When the lifting control unit performs the lifting operation, pressing the lifting button activates the hydraulic push rod motor, raising the plow blade on the plow-type unloader to the lifting position sensing area. This causes the normally closed contact of the lifting intermediate relay to become a normally open contact, releasing the lifting contactor and stopping the hydraulic push rod motor.

[0017] Furthermore, both the pressure limit switch and the lifting limit switch employ capacitive proximity sensors.

[0018] Furthermore, the system also includes a pressure-in-place indicator light;

[0019] The pressure-in-place indicator light is connected in parallel with the pressure-in-place intermediate relay coil. When the plow blade on the plow-type unloader is pressed into the pressure-in-place sensing area by the hydraulic push rod motor, the pressure-in-place intermediate relay coil is energized, and the pressure-in-place indicator light on the machine control box illuminates.

[0020] Furthermore, the system also includes a lifting position indicator light;

[0021] The lifting position indicator light is connected in parallel with the lifting intermediate relay coil. When the plow blade on the plow unloader is lifted into the lifting position sensing area by the hydraulic push rod motor, the lifting intermediate relay coil is energized, and the lifting position indicator light on the machine side control box illuminates.

[0022] This invention also proposes an electrical limit control method for a pulverized coal belt plow unloader, which is based on an electrical limit control system for a pulverized coal belt plow unloader, and includes the following steps:

[0023] When the conversion module is in the machine-side position, the control unit is pressed down to control the hydraulic push rod motor to work. When the plow blade on the plow unloader presses down to the position of the limit switch, the hydraulic push rod motor stops working.

[0024] When the conversion module is moved to a position away from the machine, the lifting control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader is raised to the position of the lifting limit switch, the motor stops.

[0025] Furthermore, the method also includes: jogging down the press button and the lift button, stopping the hydraulic push rod at the position where it is mechanically installed and matched with the plow blade of the plow-type unloader, thus completing the installation of the connecting pin.

[0026] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0027] This invention proposes an electrical limit control system and method for a pulverized coal conveyor belt plow-type unloader. The system includes a conversion module, a pressing control unit, a lifting control unit, a pressing limit switch, and a lifting limit switch. The conversion module has a first wire connected to the input terminal of the pressing control unit, and a second wire connected to the input terminal of the lifting control unit. The pressing limit switch is connected to the enable terminal of the pressing control unit, and the lifting limit switch is also connected to the enable terminal of the lifting control unit. When the conversion module is switched to the machine-side position, the pressing control unit controls the hydraulic push rod motor to operate. When the plow blade on the plow-type unloader presses down to the position of the pressing limit switch, the hydraulic push rod motor stops operating. When the conversion module is switched to the position away from the machine-side position, the lifting control unit controls the hydraulic push rod motor to operate. When the plow blade on the plow-type unloader is lifted to the position of the lifting limit switch, the motor stops operating. Based on this electrical limit control system for a pulverized coal conveyor belt plow-type unloader, a method for electrical limit control of the pulverized coal conveyor belt plow-type unloader is also proposed. This invention solves the problem that mechanical travel limit switches require precise matching with the moving parts of a plow-type unloader, necessitating repeated adjustments, resulting in long installation and debugging times and low work efficiency. Capacitive proximity sensors offer high accuracy, providing very high precision and repeatability.

[0028] This invention solves the problem that during the descent of a plow-type unloader, due to inertia, the hydraulic push rod frequently overruns the ball bearing of the mechanical travel limit switch, resulting in no signal feedback from the machine's control box and the inability to transmit the signal to the computer screen via PLC. This necessitates on-site confirmation by production workers before operating the equipment, causing inconvenience. The capacitive proximity sensor eliminates the need for contact with the target, improving safety for the environment, personnel, and machinery.

[0029] This invention solves the problem that replacing the hydraulic push rod of a plow-type unloader typically requires manual operation on-site. Because the electrical control circuit uses a contactor self-holding mechanism, the mechanical hydraulic push rod cannot be precisely fitted with the plow blades on the plow-type unloader. This invention allows for precise and rapid installation of the connecting pin by pressing the down or up button, stopping the hydraulic push rod at the mechanically fitted position with the plow blades of the plow-type unloader.

[0030] This invention solves the problems of high maintenance costs and the need for mechanical travel limit switches to collide with the hydraulic push rod to transmit signals. Mechanical limit switches also have many moving parts (mostly plastic), resulting in short lifespans and the need for regular maintenance after prolonged use. The capacitive proximity sensor in this invention does not require contact with the target, has a simple structure, does not wear or damage the object being detected, has lower cost, high reliability, and can operate quickly and accurately even in harsh environments, making it particularly suitable for metal detection.

[0031] This invention solves the problem that mechanical limit switches have two pairs of contacts, resulting in numerous control circuits, harsh field environments, and susceptibility to short circuits, grounding faults, and other electrical circuit failures. This invention requires only one pair of contacts in the field, resulting in fewer control circuits, simpler maintenance, and faster fault handling. Attached Figure Description

[0032] like Figure 1 This is a schematic diagram of the electrical limit control system of a pulverized coal belt plow unloader in the prior art;

[0033] like Figure 2 This is a schematic diagram of an electrical limit control system for a coal injection belt plow unloader proposed in Embodiment 1 of the present invention. Detailed Implementation

[0034] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted in this invention to avoid unnecessarily limiting the invention.

[0035] Example 1

[0036] Embodiment 1 of this invention proposes an electrical limit control system for a pulverized coal belt plow unloader, used to solve the frequent failure of the mechanical travel limit switch in the pulverized coal belt plow unloader. The system includes: a conversion module, a pressing control unit, a lifting control unit, a pressing limit switch, and a lifting limit switch;

[0037] The conversion module has a first path connected to the input terminal of the pressing control unit via a wire, and a second path connected to the input terminal of the lifting control unit via a wire; the pressing limit switch is connected to the enable terminal of the pressing control unit; the lifting limit switch is connected to the enable terminal of the lifting control unit.

[0038] When the conversion module is converted to the machine-side position, the pressure control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader presses down to the pressure limit switch position, the hydraulic push rod motor stops working. When the conversion module is converted to the position away from the machine-side position, the lifting control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader is lifted to the lifting limit switch position, the motor stops working.

[0039] The conversion module uses a conversion switch SA;

[0040] like Figure 2 This is a schematic diagram of an electrical limit control system for a pulverized coal conveyor plow-type unloader according to Embodiment 1 of the present invention. The present invention... Figure 1 Based on the existing electrical limit control system connection diagram of the pulverized coal conveyor plow unloader, line 7 in the control principle diagram is removed, the self-holding devices of contactors KM1 and KM2 are removed, and the original mechanical travel limit switches are removed on site. Lines 11 and 17 in the control cabinet are removed. Line 9 is connected to the normally closed contact of the lifting contactor KM2 through the normally closed contact of the pressing intermediate relay KA2. Line 15 is connected to the normally closed contact of the pressing contactor KM1 through the normally closed contact of the lifting intermediate relay KA3. Line 3 is connected to one end of the capacitor proximity sensor, and lines 23 and 25 are connected from the other end to the coils of the pressing intermediate relay KA2 and the lifting intermediate relay KA3.

[0041] Figure 2 The system also includes a remote control unit; the remote control unit is connected to the input terminals of the pressing control unit and the lifting control unit via wires, and automatically controls the pressing control unit to perform pressing and lifting operations. In this application, when the selector switch is in the automatic position, the computer can control the contactor coil through the PLC, and automatically release the contactor when it reaches the automatic position. The automatic control is not a jogging operation, and remote control can be realized.

[0042] The system also includes a stop module; the stop module is connected in series with the conversion module; the stop module is connected to the input terminals of the pressing control unit and the lifting control unit respectively via wires, and is used to stop the operation in time when a fault occurs during the pressing or lifting process. The stop module uses a stop button SB1.

[0043] The pressing control unit includes a pressing button SB2, a normally closed contact KA2 of the pressing intermediate relay, and a pressing contactor KM1 connected in series. When the pressing control unit performs the pressing operation, pressing the pressing button SB2 causes the hydraulic push rod motor to move the plow blade on the plow unloader to press into the pressing position sensing area. The normally closed contact KA2 of the pressing intermediate relay then becomes a normally open contact, the pressing contactor KM1 is released, and the hydraulic push rod motor stops working.

[0044] The lifting control unit includes a lifting button SB3, a normally closed contact KA3 of the lifting intermediate relay, and a lifting contactor KM2 connected in series. When the lifting control unit performs a lifting operation, pressing the lifting button SB3 causes the hydraulic push rod motor to move the plow blade on the plow unloader to the lifting position sensing area. At this point, the normally closed contact KA3 of the lifting intermediate relay becomes a normally open contact, the lifting contactor KM2 is released, and the hydraulic push rod motor stops working.

[0045] Both the pressure limit switch SQ1 and the lifting limit switch SQ2 use capacitive proximity sensors. The capacitive proximity sensors SQ1 and SQ2 are both EH15-G30-A1, Ue: 90-250VAC, Ie: 300MA, Sn: 15mm. The normally closed contact of the intermediate relay KA2 is a normally closed passive contact, and the normally closed contact of the intermediate relay KA3 is also a normally closed passive contact.

[0046] The system also includes a pressing-in indicator light HL1; the pressing-in indicator light HL1 is connected in parallel with the coil of the pressing intermediate relay KA2, and is used to energize the coil of the pressing intermediate relay KA2 when the plow blade on the plow unloader is pressed into the pressing-in sensing area by the hydraulic push rod motor, and the pressing-in indicator light HL1 on the machine side control box lights up.

[0047] The system also includes a lifting position indicator light HL2; the lifting position indicator light HL2 is connected in parallel with the coil of the lifting intermediate relay KA3, and is used to energize the coil of the lifting intermediate relay KA3 when the plow blade on the plow unloader is lifted into the lifting position sensing area by the action of the hydraulic push rod motor, and the lifting position indicator light HL2 on the machine side control box lights up.

[0048] Figure 2 In operation: When the selector switch SA is in the machine-side position, pressing the down button SB2 activates the hydraulic push rod motor, causing the plow blades on the plow-type unloader to press into the down-position sensing area. This energizes the coil of the down-position relay KA2, illuminating the down-position indicator light on the machine-side control box. The normally closed contact of the down-position relay KA2 then changes to a normally open contact, releasing the down-position contactor KM1 and stopping the motor. When pressing the down button SB3, the hydraulic push rod motor activates, raising the plow blades on the plow-type unloader to the lifting-position sensing area. This energizes the coil of the lifting relay KA3, illuminating the lifting-position indicator light on the machine-side control box. The normally closed contact of the lifting relay KA3 then changes to a normally open contact, releasing the lifting contactor KM2 and stopping the motor.

[0049] When replacing the hydraulic push rod of the plow unloader, press the down button SB2 and the up button SB3 intermittently. The hydraulic push rod will stop at the position where it is mechanically installed with the plow blade of the plow unloader, which can accurately and quickly complete the installation of the connecting pin.

[0050] When the selector switch is set to the automatic position, the computer can control the contactor coil via the PLC. When the position is reached, the contactor will automatically release. This automatic control is not a jogging operation and can achieve remote control.

[0051] The electrical limit control system for a coal injection belt plow unloader proposed in Embodiment 1 of this invention achieves precise matching between the mechanical travel limit switch and the moving parts of the plow blade of the plow unloader.

[0052] Example 2

[0053] Based on the electrical limit control system for a pulverized coal belt plow unloader proposed in Embodiment 1 of the present invention, Embodiment 2 of the present invention also proposes an electrical limit control method for a pulverized coal belt plow unloader, the process of which includes:

[0054] When the conversion module is in the machine-side position, the control unit is pressed down to control the hydraulic push rod motor to work. When the plow blade on the plow unloader presses down to the position of the limit switch, the hydraulic push rod motor stops working.

[0055] When the conversion module is moved to a position away from the machine, the lifting control unit controls the hydraulic push rod motor to work. When the plow blade on the plow unloader is raised to the position of the lifting limit switch, the motor stops.

[0056] The method also includes: jogging down the press button and the lift button, stopping the hydraulic push rod in the position where it is mechanically installed with the plow blade of the plow unloader, thus completing the installation of the connecting pin.

[0057] The present invention provides an electrical limit control method for a pulverized coal conveyor plow unloader, which achieves precise matching between the mechanical travel limit switch and the moving parts of the plow blade of the plow unloader.

[0058] The description of the relevant parts of the electrical limit control method for a pulverized coal belt plow unloader provided in this application embodiment can be found in the detailed description of the corresponding parts of the electrical limit control system for a pulverized coal belt plow unloader provided in Embodiment 1 of this application, and will not be repeated here.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0060] While specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art can make other modifications or variations based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A coal belt plow unloader electrical limit control system, characterized in that, The system comprises a conversion module, a pressing control unit, a lifting control unit, a pressing limit switch and a lifting limit switch; The first path of the conversion module is connected to the input end of the pressing control unit through a wire, and the second path is connected to the input end of the lifting control unit through a wire; the pressing limit switch is connected to the enable end of the pressing control unit; and the lifting limit switch is connected to the enable end of the lifting control unit; When the conversion module is converted to the machine-side position, the pressing control unit controls the hydraulic push rod motor to work, and when the plow on the plow unloader presses to the position of the pressing limit switch, the hydraulic push rod motor stops working; when the conversion module is converted to the position away from the machine-side position, the lifting control unit controls the hydraulic push rod motor to work, and when the plow on the plow unloader is lifted to the position of the lifting limit switch, the motor stops working; The pressing control unit comprises a pressing button, a pressing intermediate relay normally closed contact and a pressing contactor connected in series; when the pressing operation is performed, the pressing button is pressed, the hydraulic push rod motor drives the plow on the plow unloader to press into the pressing position sensing area, the pressing intermediate relay normally closed contact becomes a normally open contact, the pressing contactor is released, and the hydraulic push rod motor stops working; The lifting control unit comprises a lifting button, a lifting intermediate relay normally closed contact and a lifting contactor connected in series; when the lifting operation is performed, the lifting button is pressed, the hydraulic push rod motor drives the plow on the plow unloader to lift into the lifting position sensing area, the lifting intermediate relay normally closed contact becomes a normally open contact, the lifting contactor is released, and the hydraulic push rod motor stops working; The system further comprises a stop module; the stop module is connected in series with the conversion module; The stop module is connected to the input end of the pressing control unit and the input end of the lifting control unit through wires, so as to stop the operation in time when a fault occurs during pressing or lifting; The pressing limit switch and the lifting limit switch are both capacitive proximity sensors.

2. The electrical limit control system of a coal belt plow unloader according to claim 1, characterized in that, The system further comprises a remote control unit; The remote control unit is connected to the input end of the pressing control unit and the input end of the lifting control unit through wires, so as to automatically control the pressing control unit to perform the pressing operation and the lifting operation.

3. The electrical limit control system of a coal belt plow unloader according to claim 1, characterized in that, The system further comprises a pressing position indication lamp; The pressing position indication lamp is connected in parallel with the pressing intermediate relay coil, so as to make the pressing intermediate relay coil electrified when the hydraulic push rod motor drives the plow on the plow unloader to press into the pressing position sensing area, and the pressing position indication lamp of the machine-side operation box is bright.

4. The electrical limit control system of a coal belt plow unloader according to claim 1, characterized in that, The system further comprises a lifting position indication lamp; The lifting position indication lamp is connected in parallel with the lifting intermediate relay coil, so as to make the lifting intermediate relay coil electrified when the hydraulic push rod motor drives the plow on the plow unloader to lift into the lifting position sensing area, and the lifting position indication lamp of the machine-side operation box is bright.

5. A method for electrically limiting the control of a plow-type unloader of a coal injection belt, which is implemented based on the electrically limiting control system of a plow-type unloader of a coal injection belt according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: The conversion module is converted to the machine-side position, and the pressing control unit controls the hydraulic push rod motor to work, and when the plow on the plow unloader presses to the position of the pressing limit switch, the hydraulic push rod motor stops working; The conversion module is converted to a position far from the machine, the lifting control unit controls the hydraulic push rod motor to work, and the motor stops when the plow of the plow unloader is lifted to the position of the lifting limit switch.

6. The electrical limit control method of a coal injection belt plow unloader according to claim 5, characterized in that, The method further comprises: the jog down button and the lifting button are pressed, the hydraulic push rod is stopped at the position of the mechanical installation cooperation of the plow unloader plow, and the connecting pin installation is completed.

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