An internally powered parallel closed indicating belt pull rope switch

Abstract

The utility model relates to the technical field of industrial automation control, and specifically is an internally powered parallel closed indicating belt pull rope switch, wherein the pull rope switch unit and the control circuit unit are arranged one by one, and the control circuit unit includes a fuse FU, a light emitting diode LED and a voltage stabilizing diode DZ, one end of the fuse FU is electrically connected to the pull rope switch contact LK in the pull rope switch unit, and the other end of the fuse FU is electrically connected to the anode of the light emitting diode LED and the cathode of the voltage stabilizing diode DZ, and the cathode of the light emitting diode LED and the anode of the voltage stabilizing diode DZ are both electrically connected to a current limiting resistor R. The utility model closely integrates the control circuit unit with the pull rope switch unit, reduces the need for external wiring and an independent control box, reduces the floor space and maintenance cost of the equipment, simplifies the installation and maintenance process, and improves the overall reliability and waterproof and dustproof performance of the system.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial automation control, in particular to an internal power supply parallel mode closed indicating belt pull rope switch. Background Art

[0002] In the design and operation of modern thermal power plants, the efficient and safe operation of the coal conveying system is one of the key factors to ensure continuous power supply. The belt transportation link in the coal conveying system pays special attention to its safety protection measures to prevent shutdowns or safety accidents caused by faults. Among them, the accident pull rope protection switch, as an important safety device, is widely used to monitor emergency situations along the conveyor belt. Once the staff finds abnormalities or dangers, they can immediately stop the belt operation by pulling the pull rope set along the line, so as to respond quickly and avoid potential accidents.

[0003] According to industry standards such as the Technical Regulations for Coal Transportation Design in Thermal Power Plants, each coal conveyor belt must be equipped with a complete rope protection system, and common implementation methods include connecting rope protection switches in series or in parallel. However, in actual applications, traditional belt rope protection monitoring solutions, especially those that rely on local protection control boxes, have gradually exposed many deficiencies.

[0004] First, from the perspective of system design, the current control circuit is relatively complex. Not only does it require a separate working power supply for each protection box, but the number of intermediate relays involved in the signal indication and output process increases, which not only increases the difficulty of system maintenance, but also reduces the reliability and stability of the overall protection. Any failure in the intermediate link may affect the normal execution of the pull rope protection function, thereby threatening the safety of coal transportation operations.

[0005] Secondly, considering the working environment characteristics of thermal power plants, the coal transportation area is often accompanied by a large amount of dust, which directly leads to serious dust accumulation inside the local protection control box. After long-term accumulation, electrical components such as relays are prone to poor contact or even failure, which not only affects daily monitoring and control, but also buries major safety hazards such as fire, posing a severe challenge to the safe production of power plants.

[0006] Furthermore, from the perspective of operation and maintenance convenience, the existing centralized status display design (i.e. aggregating multiple pull-wire switch signals into a single control box display) is not conducive to daily inspections and troubleshooting. Since the pull-wire switches are widely distributed, this layout makes it difficult for technicians to intuitively and quickly locate which pull-wire switch triggered the protection action during maintenance or testing, affecting response speed and maintenance efficiency.

[0007] Therefore, in view of the defects of the current coal conveyor belt rope protection control system, such as complex structure, difficult maintenance, high fire risk and inconvenient observation, there is an urgent need for a more simplified, reliable and easy-to-maintain protection solution to meet the higher requirements of modern thermal power plants for efficient and safe operation. Utility Model Content

[0008] The utility model aims to provide an internally powered parallel closed indicating belt pull rope switch to solve the problems raised in the above background technology.

[0009] The technical solution of the utility model is: an internally powered parallel closed indicating belt pull-cord switch, comprising a pull-cord switch unit and a control circuit unit, wherein the pull-cord switch unit and the control circuit unit are arranged in a one-to-one correspondence, and the control circuit unit comprises a fuse FU, a light-emitting diode LED and a voltage-stabilizing diode DZ, one end of the fuse FU is electrically connected to a pull-cord switch contact LK in the pull-cord switch unit, the other end of the fuse FU is electrically connected to an anode of the light-emitting diode LED and a cathode of the voltage-stabilizing diode DZ, and the cathode of the light-emitting diode LED and the anode of the voltage-stabilizing diode DZ are both electrically connected to a current-limiting resistor R.

[0010] Preferably, the control circuit unit is arranged inside the pull-cord switch unit.

[0011] Preferably, the light emitting diode LED is arranged outside the pull-cord switch unit.

[0012] Preferably, the light emitting diode LED is connected in parallel with a buzzer.

[0013] Preferably, the control circuit unit further includes an internal power supply module, one end of the internal power supply module is electrically connected to the pull-cord switch contact LK and the anode of the voltage-stabilizing diode DZ, and the other end of the internal power supply module is electrically connected to the remote control system.

[0014] Preferably, the internal power supply module is configured as a two-wire connection, and the two-wire connection includes but is not limited to a power line and a signal line;

[0015] The power cord is used for loop power supply;

[0016] The signal line is used to transmit signals.

[0017] Preferably, the query voltage of the remote control system includes but is not limited to DC24V and DC48V.

[0018] The utility model provides an internal power supply parallel closed indicating belt pull rope switch through improvement, which has the following improvements and advantages compared with the prior art:

[0019] Firstly, the utility model integrates the control circuit unit with the pull-cord switch unit tightly, reduces the need for external wiring and independent control boxes, reduces the floor space and maintenance cost of the equipment, simplifies the installation and maintenance process, improves the overall reliability and waterproof and dustproof performance of the system, and at the same time, the direct signal feedback path reduces the intermediate links of signal transmission, reduces the failure points, and improves the overall reliability and safety of the device;

[0020] Second: the utility model does not need to provide additional working power for the pull-cord switch's built-in indicator light, and adopts a two-wire wiring method, which not only provides the necessary working power for the pull-cord switch's built-in prompt circuit, but also serves as a signal transmission medium, directly connecting with the remote control system, thereby simplifying the wiring structure and improving the system's response speed and compatibility;

[0021] Thirdly, the light emitting diode (LED) arranged outside the utility model can directly indicate the status of the pull rope switch, and the optional buzzer can provide dual warnings of sound and light, so that the operator can quickly identify and respond to emergency situations, thereby greatly enhancing the overall safety and emergency handling capabilities of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The utility model is further explained below in conjunction with the accompanying drawings and embodiments:

[0023] Figure 1 The utility model discloses a circuit diagram of a closed indicating belt pull rope switch in parallel mode with internal power supply. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that, in the description of the present invention, the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0026] Furthermore, it should be understood that for the sake of ease of description, the sizes of the various components shown in the drawings are not drawn according to actual proportions. For example, the thickness or width of certain layers may be exaggerated relative to other layers.

[0027] It should be noted that like reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined or described in one drawing, it will not require further detailed discussion and description in the description of the subsequent drawings.

[0028] refer to Figure 1 The present embodiment provides an internally powered parallel closed indicating belt pull rope switch, which is intended to optimize the pull rope protection mechanism in the traditional coal transportation system and improve safety and maintenance convenience. Specifically, the internally powered parallel closed indicating belt pull rope switch includes a pull rope switch unit and a control circuit unit, and the pull rope switch unit and the control circuit unit are arranged one-to-one, that is, in the present embodiment, the pull rope switch unit and the control circuit unit are tightly integrated, and each set of the pull rope switch unit operates independently without affecting each other.

[0029] In this embodiment, the control circuit unit includes a fuse FU, a light emitting diode LED, a voltage stabilizing diode DZ and a current limiting resistor R. One end of the fuse FU is electrically connected to the pull-cord switch contact LK in the pull-cord switch unit, and the other end of the fuse FU is electrically connected to the anode of the light emitting diode LED and the cathode of the voltage stabilizing diode DZ, while the cathode of the light emitting diode LED and the anode of the voltage stabilizing diode DZ are electrically connected to the current limiting resistor R. It is worth noting that the light emitting diode LED in the control circuit unit can be replaced with a low-power buzzer, and the light emitting diode LED in the control circuit unit can also be directly connected in parallel with the low-power buzzer. That is to say, in addition to the visual indication, in this embodiment, it is also preferred to equip a buzzer to be connected in parallel with the light emitting diode LED and the voltage stabilizing diode DZ. Once the pull cord is actuated, the buzzer will simultaneously emit an alarm sound, thereby enhancing the warning effect in an emergency.

[0030] Furthermore, when the internal power supply parallel closed indication belt pull rope switch in this embodiment is in normal operation, the pull rope switch will be in a non-operation state. At this time, the pull rope switch contact LK is disconnected, the electrical circuit has no current, and the light-emitting diode LED does not emit light, thereby indicating that the pull rope switch is in a non-operation state. Similarly, when the pull rope switch is in an operation state, the pull rope switch contact LK is closed, and the circuit current flows through the pull rope switch contact LK and the fuse FU through the light-emitting diode LED and the current-limiting resistor R, that is, the light-emitting diode LED works and emits light, thereby indicating that the pull rope switch is in an operation state. In other words, the pull rope switch contact LK in this embodiment is disconnected in a non-operation state and closed in an operation state. The fuse FU is used to protect the circuit from damage when the input voltage or current is abnormal, that is, when the circuit input voltage or current is too high, it can effectively protect the voltage regulator diode DZ from overcurrent damage, wherein the specific value of the fuse FU can be set by specific calculation according to the current that the actually selected voltage regulator diode DZ can withstand. The voltage zener diode DZ is used to limit the voltage across the LED and the current limiting resistor R to ensure safe operation of the components, i.e. to avoid damage to the LED caused by excessive voltage. The LED serves as a direct visual indication of the pull-cord switch action. The current limiting resistor R is configured in the circuit branch of the LED to regulate the current flowing through the LED to prevent overload. The resistance setting of the current limiting resistor R can be calculated and designed based on the voltage stabilization value of the voltage zener diode DZ and the maximum allowable current of the LED.

[0031] In this embodiment, some components in the control circuit unit are arranged inside the pull-cord switch unit. Specifically, in the control circuit unit, the light-emitting diode LED is arranged outside the pull-cord switch unit, so that the action of the pull-cord switch can be more intuitively observed through the working state of the light-emitting diode LED. In other words, the light-emitting diode LED is installed in a conspicuous position outside the pull-cord switch unit. When the pull cord is pulled, that is, when the pull-cord switch contact LK is closed, the light-emitting diode LED lights up, providing a clear visual indication, which is convenient for the inspection personnel to quickly identify the pull-cord switch state. At the same time, such a design can also simplify external wiring, reduce the demand for installation space, and enhance the waterproof and dustproof performance of the system.

[0032] Furthermore, the control circuit unit is also provided with an internal power supply module, one end of which is electrically connected to the pull-cord switch contact LK and the anode of the voltage-stabilizing diode DZ, and the other end of which is electrically connected to the remote control system. The query voltage of the remote control system is the voltage input signal of the input module, and the query voltage includes but is not limited to DC24V and DC48V. In this embodiment, the query voltage U abIt can be set to a two-wire connection, which includes but is not limited to a power line and a signal line, that is, the internal power supply module U ab It can be used as a power line to supply power and as a signal line to transmit signals. ab It is usually the query voltage from the DI (switch signal input) channel of the DCS system, and also provides working power for the internal power supply parallel mode closed indication belt pull rope switch in this embodiment. ab The current of the connected electrical circuit reaches the preset current value, or the internal power supply module U ab When the voltage of the connected electrical circuit is lower than the preset voltage value, the DI channel of the DCS system can collect the input protection signal. That is, when the pull-cord switch contact LK is closed, the DI channel of the DCS system can collect the protection signal. In other words, when the internal power supply module U ab The design realizes the dual functions of power supply and signal. The two-wire system not only simplifies the on-site wiring, but also supports common query voltages such as DC24V or DC48V, thereby improving the compatibility and versatility of the internal power supply parallel closed indication belt pull rope switch in this embodiment. It is worth noting that the preset voltage value and the preset current value in this embodiment do not have clear value sizes, which can be obtained by specific calculation according to the needs of the user.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An internally powered parallel closed indicating belt pull rope switch, characterized in that: It includes a pull-cord switch unit and a control circuit unit, and the pull-cord switch unit and the control circuit unit are arranged in a one-to-one correspondence. At the same time, the control circuit unit includes a fuse FU, a light-emitting diode LED and a voltage-stabilizing diode DZ. One end of the fuse FU is electrically connected to the pull-cord switch contact LK in the pull-cord switch unit, and the other end of the fuse FU is electrically connected to the anode of the light-emitting diode LED and the cathode of the voltage-stabilizing diode DZ. At the same time, the cathode of the light-emitting diode LED and the anode of the voltage-stabilizing diode DZ are electrically connected to a current-limiting resistor R.

2. According to claim 1, the internally powered parallel closed indicating belt pull rope switch is characterized in that: The control circuit unit is arranged inside the pull-cord switch unit.

3. The internally powered parallel closed indicating belt pull rope switch according to claim 1, characterized in that: The light emitting diode LED is arranged outside the pull-cord switch unit.

4. The internally powered parallel closed indicating belt pull rope switch according to claim 1, characterized in that: The light emitting diode LED and the voltage stabilizing diode DZ are both connected in parallel with a buzzer.

5. An internally powered parallel closed indicating belt pull rope switch according to claim 1 or 2, characterized in that: The control circuit unit also includes an internal power supply module Uab, one end of the internal power supply module Uab is electrically connected to the pull-cord switch contact LK and the anode of the voltage-stabilizing diode DZ, and the other end of the internal power supply module Uab is electrically connected to the remote control system.

6. The internally powered parallel closed indicating belt pull rope switch according to claim 5, characterized in that: The internal power supply module Uab is configured as a two-wire connection, wherein the two-wire connection includes a power line and a signal line; The power cord is used for loop power supply; The signal line is used to transmit signals.

7. The internally powered parallel closed indicating belt pull rope switch according to claim 5, characterized in that: The query voltage of the remote control system includes commonly used DC24V and DC48V.

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