A control system for a coal bunker loosening machine

Abstract

This disclosure provides a control system for a coal bunker loosening machine, including: a PLC controller, N first relays, a first power supply, a second power supply, and N air hammer solenoid valves; each first relay includes a first relay coil and a normally open contact; the positive terminal of the first power supply is connected to the first power supply pin of the PLC controller, and the N output contacts of the PLC controller are respectively connected to one end of the N first relay coils, the other end of the N first relay coils are all connected to the negative terminal of the first power supply; the positive terminal of the second power supply is connected to one end of the N normally open contacts, the other end of the N normally open contacts are respectively connected to one side of the power supply terminal of the N air hammer solenoid valves, and the other side of the power supply terminal of the N air hammer solenoid valves are all connected to the negative terminal of the second power supply; the supply voltage of the first power supply is lower than the supply voltage of the second power supply. This disclosure, through the isolation design of the relays, avoids arc wear of the output contacts caused by high voltage, significantly improving the service life of the PLC module.

Description

Technical Field

[0001] This disclosure relates to the field of industrial automation control technology, and in particular to a control system for a coal bunker loosening machine. Background Technology

[0002] A Programmable Logic Controller (PLC) is a digital electronic system specifically designed for industrial applications. It uses a programmable memory to store instructions for performing logical operations, sequential control, timing, counting, and arithmetic operations, controlling various types of machinery or production processes through digital or analog inputs and outputs.

[0003] Currently, the common terminal 4L+ of the PLC control system of the coal bunker loosening machine is directly connected to a 220V power supply, and directly drives the air hammer solenoid valve through several output nodes. In actual operation, the 220V high voltage is directly applied to the PLC output port, and the output nodes need to perform intermittent switching actions for a long time under conditions such as the operation of the unblocking machine motor and the triggering of the coal cut-off signal. The output contacts are prone to wear and aging due to frequent arc discharge, and may even experience contact adhesion or failure to output voltage normally. This requires frequent replacement of PLC modules, increasing maintenance costs and downtime. Utility Model Content

[0004] The purpose of this disclosure is to provide a control system for a coal bunker loosening machine to solve the problem of easily damaged system hardware in the prior art.

[0005] The embodiments of this disclosure adopt the following technical solution: a control system for a coal bunker loosening machine, comprising: a PLC controller, N first relays, a first power supply, a second power supply, and N air hammer solenoid valves; wherein, each first relay includes a first relay coil and a normally open contact, and N is a positive integer greater than 1; the positive terminal of the first power supply is connected to the first power supply pin of the PLC controller, the N output contacts of the PLC controller are respectively connected to one end of the N first relay coils, and the other end of the N first relay coils is connected to the negative terminal of the first power supply; the positive terminal of the second power supply is connected to one end of the N normally open contacts, the other end of the N normally open contacts are respectively connected to one side power supply terminal of the N air hammer solenoid valves, and the other side power supply terminal of the N air hammer solenoid valves is connected to the negative terminal of the second power supply; the supply voltage of the first power supply is less than the supply voltage of the second power supply.

[0006] In some embodiments, the system further includes a manual activation switch; one end of the manual activation switch is connected to the manual control pin of the PLC controller, and the other end of the manual activation switch is connected to the positive terminal of the first power supply.

[0007] In some embodiments, each normally open contact is connected in series with the power supply terminal of its corresponding air hammer solenoid valve via an air switch.

[0008] In some embodiments, the system further includes: an alarm and N second relays, each second relay comprising a second relay coil and a normally closed contact; each air switch is connected in series with the power supply terminal of its corresponding air hammer solenoid valve via a second relay coil; one end of all normally closed contacts is connected to the positive terminal of the first power supply, and the other end of all normally closed contacts is connected to the alarm pin of the PLC controller; the alarm is connected in series between the alarm output contact of the PLC controller and the negative terminal of the first power supply.

[0009] In some embodiments, the system further includes: N indicator lights; each air switch is connected in series with the power supply terminal of its corresponding air hammer solenoid valve.

[0010] In some embodiments, the air hammer solenoid valve is a single-electrically controlled direct-acting solenoid valve or a two-position two-way solenoid valve.

[0011] In some embodiments, the second power supply is also used to supply power to the PLC controller.

[0012] In some embodiments, the first power supply is a 24V power supply and the second power supply is a 220V power supply.

[0013] The beneficial effects of this embodiment are as follows: by using the isolation design of the first relay, the output contacts of the PLC controller are powered by a first power supply with a lower supply voltage, which avoids arc wear of the output contacts caused by high-voltage load, significantly improves the reliability of the PLC module and extends its service life; at the same time, the electromagnetic isolation effect of the first relay effectively suppresses the back electromotive force interference when the air hammer solenoid valve is switched on and off, reduces the probability of system malfunction and enhances control stability. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in 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 some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the hardware connection circuit of the control system of a coal bunker loosening machine in the prior art;

[0016] Figure 2This is a system structure diagram of the control system of the coal bunker loosening machine in an embodiment of this disclosure;

[0017] Figure 3 This is another system structure diagram of the control system of the coal bunker loosening machine in this embodiment of the present disclosure;

[0018] Figure 4 This is a schematic diagram of the hardware connection circuit of the control system of the coal bunker loosening machine in this embodiment of the present disclosure;

[0019] Figure 5 This is a schematic diagram of another hardware connection loop of the control system of the coal bunker loosening machine in this embodiment of the present disclosure. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0021] A PLC is a digital electronic system specifically designed for industrial applications. It uses a programmable memory to store instructions for performing logical operations, sequential control, timing, counting, and arithmetic operations, and controls various types of mechanical equipment or production processes through digital or analog inputs and outputs.

[0022] Currently, the common terminal 4L+ of the PLC control system of the coal bunker loosening machine is directly connected to a 220V power supply, such as... Figure 1 As shown, the air hammer solenoid valve is directly driven through output nodes Q1.4, Q1.5, Q1.6, and Q1.7. In actual operation, 220V high voltage is directly applied to the PLC output port, and the output nodes need to perform intermittent switching actions for a long time under conditions such as the operation of the unblocking machine motor and the triggering of the coal cut-off signal. The output contacts are prone to wear and aging due to frequent arc discharge, and may even experience contact adhesion or failure to output voltage normally. This requires frequent replacement of the PLC module, increasing maintenance costs and downtime.

[0023] Furthermore, the original program logic only relies on automatic triggering conditions (such as the coal cut-off signal I0.5) to control the air hammer's operation, without setting a manual activation interface. During equipment maintenance, temporary shutdowns, or unnecessary operating conditions, the air hammer's operation cannot be directly terminated through the program; the only solution is to disconnect the external circuit breaker to cut off the physical circuit. However, the PLC output nodes continue to perform intermittent switching, causing the ports to be in an "invalid action" state, further exacerbating component wear. The external circuit breaker can only achieve mechanical power disconnection and cannot intervene in the output logic at the program level, creating an unreasonable operating mode of "circuit disconnected but program running idle." Over time, this not only increases energy consumption but may also lead to a decrease in control system stability due to repeated port loading, affecting the continuity of the coal bunker loosening process.

[0024] To address the aforementioned problems, embodiments of this disclosure provide a control system for a coal bunker loosening machine, the system structure of which is shown in the figure below. Figure 2 As shown, the system mainly includes a PLC controller 10, N first relays 20, a first power supply 30, a second power supply 40, and N air hammer solenoid valves 50. Each first relay 20 includes a first relay coil 21 and a normally open contact 22. That is, when the first relay coil 21 is energized, the corresponding normally open contact 22 closes. N is a positive integer greater than 1, and is usually consistent with the number of air hammers set in the actual coal bunker loosening machine. Figure 2 Taking N=4 as an example, that is, the number of the first relay 20, the air hammer solenoid valve 50 and the air hammer are all 4.

[0025] like Figure 2 As shown, the positive terminal of the first power supply 30 is connected to the first power supply pin L1+ of the PLC controller 10. The N output contacts (Q1 to QN) of the PLC controller 10 are respectively connected to one end of the N first relay coils 21. The other ends of the N first relay coils 21 are all connected to the negative terminal of the first power supply 30, forming an output control loop. The positive terminal of the second power supply 40 is connected to one end of the N normally open contacts 22. The other ends of the normally open contacts 22 are respectively connected to one side of the power supply terminal of the N air hammer solenoid valves 50. The other side of the power supply terminal of the air hammer solenoid valves 50 is connected to the negative terminal of the second power supply 40, forming an air hammer control loop. In this embodiment, the air hammer solenoid valve can be a single-electrically controlled direct-acting solenoid valve, a two-position two-way solenoid valve, or any other type of solenoid valve capable of driving the air hammer.

[0026] In the actual operation of the PLC controller 10, if it is necessary to drive the air hammer to loosen the raw materials in the coal bunker, the PLC controller 10 will close the aforementioned N output contacts, making the output control circuit conductive. At this time, the N first relay coils 21 are energized, driving the normally open contact 22 to close. When the normally open contact 22 is closed, the air hammer control circuit is conductive, energizing the air hammer solenoid valve 50 to drive the air hammer to operate. In this embodiment, the supply voltage of the first power supply is lower than that of the second power supply. For example, the first power supply is a 24V low-voltage power supply, while the second power supply is a 220V high-voltage power supply. At this time, the output contacts of the PLC controller are powered by the first power supply with a lower supply voltage, avoiding arc wear of the output contacts caused by high-voltage loads, significantly improving the reliability of the PLC module and extending its service life. At the same time, the electromagnetic isolation effect of the first relays effectively suppresses the back electromotive force interference when the air hammer solenoid valve is switched on and off, reducing the probability of system malfunction and enhancing control stability.

[0027] In some embodiments, the control system further includes a manual switch 60, which is connected in series between the manual control pin I2.3 of the PLC controller and the negative terminal of the first power supply 30, such as... Figure 3 As shown. Specifically, when the manual activation switch 60 is closed, the PLC controller 10 acquires a high-level signal as the manual activation signal through the manual control pin I2.3. The PLC controller 10 uses the manual activation signal as one of the necessary conditions for the output contacts to close. Simultaneously, combined with the coal cut-off signal and the unblocking machine motor running signal that drive the air hammer under normal conditions, the output contacts (Q1 to QN) are closed, completing the subsequent driving of the air hammer solenoid valve. If the manual activation switch 60 is in the open state, even if the PLC controller can normally receive the coal cut-off signal and the unblocking machine motor running signal, the output contacts will not close, and the air hammer solenoid valve will always remain in a stopped state. It should be noted that... Figure 2 and Figure 3 The pin numbers of the PLC controller shown are for illustrative purposes only. In actual use, they can be assigned according to different PLC models and pin functions. This embodiment does not impose any restrictions.

[0028] Figure 4 A schematic diagram of the hardware connection loop of the control system of a coal bunker loosening machine is shown. Figure 4The example is shown with N being 4. Specifically, the PLC's 4L+ pin is connected to the positive terminal of the 24V power supply as its first power supply pin. Q1.4 to Q1.7 are connected to the first relay coils KA1 to KA4 as output contacts, respectively. The corresponding normally open contacts KA1 to KA4 are connected in series between the 220V power supply and the air hammer solenoid valve. The 220V power supply supplies power to both the PLC and the air hammer solenoid valve. Pin I0.5 is used to receive the coal cut-off signal. Pin I2.3 is used as the manual control pin and is connected to the manual switch 60 (the connection line between the other end of the manual switch 60 and the negative terminal of the first power supply is not shown). Q0.0 receives the unblocking machine motor running signal.

[0029] In some embodiments, an air switch 70 is connected in series between each normally open contact and the power supply terminal of its corresponding air hammer solenoid valve to protect the air hammer control circuit, including but not limited to short-circuit protection, overload protection, and fault circuit isolation protection. Further, as... Figure 5 As shown, the control system also includes an alarm 80 and N second relays. Each second relay includes a second relay coil KB1 to KB4 and corresponding normally closed contacts KB1 to KB4. A second relay coil is connected in series between the power supply terminal of each air switch 70 and its corresponding air hammer solenoid valve. One end of each normally closed contact is connected to the positive terminal of the first power supply, and the other end is connected to the alarm pin of the PLC controller (taking pin I2.4 as an example). This ensures that if any air switch 70 is opened, causing the second relay coil to be de-energized, the corresponding normally closed contact closes, allowing the PLC controller to receive an alarm signal. Additionally, the PLC controller includes an alarm output contact (taking pin Q1.8 as an example). The alarm 80 is connected in series between the alarm output contact and the negative terminal of the first power supply. Upon receiving an alarm signal, the PLC controller closes the alarm output contact, energizing the alarm and prompting on-site personnel to handle the fault.

[0030] In some embodiments, the control system may also include N indicator lights (not shown in the figure), that is, an indicator light is connected in series between each air switch and the power supply terminal of its corresponding air hammer solenoid valve to indicate the on / off status of the corresponding circuit. When the indicator light is on, it indicates that the circuit is normal, and when the indicator light is off, it indicates that the corresponding circuit is faulty and disconnected. This can help on-site operators quickly locate the faulty circuit and realize the repair and replacement of the corresponding faulty components.

[0031] This embodiment utilizes the isolation design of the first relay to power the output contacts of the PLC controller with a lower-voltage first power supply. This avoids arcing wear on the output contacts caused by high-voltage loads, significantly improving the reliability of the PLC module and extending its service life. Simultaneously, the electromagnetic isolation of the first relay effectively suppresses back EMF interference during the switching of the air hammer solenoid valve, reducing the probability of system malfunction and enhancing control stability. Furthermore, by adding a manual activation switch, this embodiment allows operators to directly pause the air hammer operation via program logic without disconnecting the physical circuit breaker, improving operational convenience and emergency response efficiency. It also avoids unnecessary port losses under unnecessary operating conditions, adapting to diverse scenarios such as equipment maintenance and temporary shutdowns.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A control system for a coal bunker loosening machine, characterized in that include: The system comprises a PLC controller, N first relays, a first power supply, a second power supply, and N air hammer solenoid valves; wherein each first relay includes a first relay coil and a normally open contact, and N is a positive integer greater than 1. The positive terminal of the first power supply is connected to the first power supply pin of the PLC controller, and the N output contacts of the PLC controller are respectively connected to one end of the N first relay coils. The other end of the N first relay coils is connected to the negative terminal of the first power supply. The positive terminal of the second power supply is connected to one end of the N normally open contacts, the other end of the N normally open contacts is connected to one side of the power supply terminal of the N air hammer solenoid valves, and the other side of the power supply terminal of the N air hammer solenoid valves is connected to the negative terminal of the second power supply. The supply voltage of the first power source is lower than the supply voltage of the second power source.

2. The control system of claim 1, wherein, Also includes: Manually activate the switch; One end of the manual switch is connected to the manual control pin of the PLC controller, and the other end of the manual switch is connected to the positive terminal of the first power supply.

3. The control system of claim 1, wherein, Each normally open contact is connected in series with the power supply terminal of its corresponding air hammer solenoid valve via an air switch.

4. The control system of claim 3, wherein Also includes: An alarm and N second relays, each second relay including a second relay coil and a normally closed contact; Each of the air switches is connected in series with the power supply terminal of its corresponding air hammer solenoid valve, and one end of all the normally closed contacts is connected to the positive terminal of the first power supply, and the other end of all the normally closed contacts is connected to the alarm pin of the PLC controller. The alarm is connected in series between the alarm output contact of the PLC controller and the negative terminal of the first power supply.

5. The control system of claim 3, wherein, Also includes: N indicator lights; Each of the aforementioned air switches is connected in series with the power supply terminal of its corresponding air hammer solenoid valve, and an indicator light is also connected to it.

6. The control system of claim 1, wherein, The air hammer solenoid valve is either a single-electric-controlled direct-acting solenoid valve or a two-position two-way solenoid valve.

7. The control system of claim 1, wherein, The second power supply is also used to supply power to the PLC controller.

8. The control system of any one of claims 1 to 7, wherein, The first power supply is a 24V power supply, and the second power supply is a 220V power supply.

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