An explosion-proof limit switch

Abstract

This utility model relates to the field of limit switch technology, specifically disclosing an explosion-proof limit switch, comprising: an explosion-proof base plate, which serves as the basic support component of the entire limit switch; a connecting plate on each side of the explosion-proof base plate; and a circuit controller installed inside the explosion-proof base plate via bolts, which is used for controlling the explosion-proof limit switch and processing circuit signals. In this explosion-proof limit switch, the explosion-proof base plate and explosion-proof shell are connected by a snap-fit ​​and sealed to form a fully sealed explosion-proof cavity, effectively isolating the switch from harsh external environments, preventing static electricity buildup and component corrosion. The contact-type signal transmission between the trigger rod and the connecting contact point accelerates signal transmission speed. The addition of a photoelectric sensor and circuit controller ensures stable operation under harsh conditions, reducing the risk of malfunction or failure within the limit switch.

Description

Technical Field

[0001] This utility model relates to the field of limit switch technology, specifically an explosion-proof limit switch. Background Technology

[0002] An explosion-proof limit switch is a safety control element used in explosive hazardous environments. It is mainly used to detect the movement position of equipment, control the travel of the mechanism, or provide limit protection. Its core function is to trigger the switch action when the equipment moves to a preset position, cut off or switch the control circuit, and prevent the equipment from overload, collision or runaway. At the same time, it must ensure that it does not generate electrical sparks, thermal effects or other ignition sources in flammable and explosive environments.

[0003] Because industrial sites are often accompanied by harsh conditions such as high temperature and pressure, corrosive dust, etc., without protective switches, problems such as mechanical wear, contact oxidation and insulation aging are likely to occur, leading to malfunctions or failures. In addition, the internal circuit layout of traditional explosion-proof limit switches is complicated, and the assembly precision requirements between various components are extremely high. Once a component fails, the repair is difficult and costly. Utility Model Content

[0004] The purpose of this utility model is to provide an explosion-proof limit switch to solve the problems mentioned in the background art, such as the high temperature, high pressure, corrosive dust and other harsh conditions in industrial sites, which can easily lead to mechanical wear, contact oxidation and insulation aging without protective switches, resulting in malfunction or failure. In addition, traditional explosion-proof limit switches have complicated internal circuit layouts and require extremely high assembly precision between components. Once a component fails, the repair is difficult and costly.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an explosion-proof limit switch, including an explosion-proof base plate, which serves as the basic support component of the entire limit switch. The explosion-proof base plate has a connecting plate on each side, and the explosion-proof base plate is engaged with the explosion-proof shell. A circuit controller is installed inside the explosion-proof base plate by bolts, and the circuit controller is used for controlling the explosion-proof limit switch and processing circuit signals.

[0006] The explosion-proof base plate is equipped with a trapezoidal limiting buckle on each side, and the limiting buckle has an opening that engages with the explosion-proof shell. The side wall of the limiting buckle is penetrated by a positioning pin, and one end of the positioning pin is inserted into the explosion-proof shell. The connecting plate is provided with mounting holes through which bolts pass.

[0007] The explosion-proof housing has rectangular openings on both sides, and a signal junction box is fixed inside the rectangular opening of the explosion-proof housing. The signal junction box is connected to the circuit controller and the photoelectric sensor respectively through cables. The upper end of the photoelectric sensor is embedded with a drive motor. The bevel gear at the output end of the drive motor is meshed with a toothed ring gear, and the toothless side of the toothed ring gear is engaged with the trigger rod.

[0008] By adopting the above technical solution, the mechanical linkage between the toothed ring and the trigger rod, combined with the electronic control of the circuit controller, achieves a dual triggering mechanism to achieve precise positioning.

[0009] Preferably, a sealing element is provided at the connection between the explosion-proof base plate and the explosion-proof shell, and the explosion-proof shell is penetrated and rotated by the connecting rod.

[0010] By adopting the above technical solution, the sealing design between the base plate and the outer shell effectively isolates flammable and explosive gases, thereby improving the explosion-proof level.

[0011] Preferably, a protruding post is provided at the connection between the explosion-proof shell and the limiting buckle, and the protruding post of the explosion-proof shell is penetrated by a positioning pin.

[0012] By adopting the above technical solution, the protruding column of the explosion-proof shell cooperates with the positioning pin to ensure accurate installation and avoid misalignment caused by vibration.

[0013] Preferably, the bottom end of the connecting rod is rotatably connected to the surface of the explosion-proof base plate, and the connecting rod and the trigger rod are an integral structure.

[0014] By adopting the above technical solution, the connecting rod and the trigger rod are integrally formed, which reduces the transmission gap and improves the trigger response speed.

[0015] Preferably, one end of the trigger rod contacts the connecting contact point and transmits an electrical signal, and the connecting contact point is connected to the circuit controller via a cable.

[0016] By adopting the above technical solution, the direct contact between the trigger rod and the connecting contact point ensures stable electrical signal transmission and strong anti-interference capability.

[0017] Preferably, the circuit controller and the photoelectric sensor are electrically connected.

[0018] By adopting the above technical solution, signals are exchanged between the circuit controller and the photoelectric sensor, providing a basis for high-frequency word triggering.

[0019] Preferably, the toothed ring is rotatably connected within the explosion-proof base plate, and the toothed ring and the connecting rod are arranged in a collar shape.

[0020] By adopting the above technical solution, the ring-shaped arrangement of the toothed ring and the connecting rod reduces the radial space occupied.

[0021] Compared with the prior art, the beneficial effects of this utility model are: This explosion-proof limit switch:

[0022] 1. The explosion-proof base plate and explosion-proof housing of this limit switch are connected by a snap-fit ​​and a sealing element is set to form a fully sealed explosion-proof cavity, which effectively isolates the harsh external environment, prevents static electricity accumulation and corrosion of components. The contact signal transmission between the trigger rod and the connecting contact point speeds up the transmission speed between signals. The addition of photoelectric sensors and circuit controllers ensures stable operation under harsh working conditions and reduces the risk of malfunction or failure.

[0023] 2. The limit switch adopts a modular structure. In actual installation, the mounting holes of the connecting plate are matched with bolts, and the limit buckle and positioning pin are detachably connected, so that the switch can be quickly fixed and the housing can be easily disassembled. When a component fails, the faulty module can be replaced quickly without complicated operation, which reduces maintenance difficulty and cost and reduces downtime.

[0024] 3. The drive motor is driven by a bevel gear meshing with a toothed ring gear. The toothed design ensures that the trigger rod is triggered only at a specific angle, reducing mechanical wear. At the same time, the drive motor and other components adopt an embedded layout, thereby reducing the overall installation area. By flexibly adapting to space-constrained equipment of different sizes, it is easy to install and move. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall external three-dimensional structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the overall side sectional three-dimensional structure of this utility model;

[0027] Figure 3 This is a three-dimensional structural diagram of the connecting rod and the toothed ring of this utility model.

[0028] Figure 4 This is a three-dimensional structural diagram of the positioning pin and explosion-proof shell of this utility model.

[0029] Figure 5 This is a schematic diagram of the installation state of the contact points and circuit controller of this utility model;

[0030] Figure 6 This is a three-dimensional structural diagram of the trigger rod, connecting contact point, and toothed ring of this utility model.

[0031] In the diagram: 1. Explosion-proof base plate; 2. Connecting plate; 3. Limiting buckle; 4. Positioning pin; 5. Explosion-proof housing; 6. Signal junction box; 7. Connecting rod; 8. Trigger rod; 9. Connecting contact point; 10. Circuit controller; 11. Photoelectric sensor; 12. Drive motor; 13. Bevel gear; 14. Missing toothed gear ring. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Please see Figures 1-6 This utility model provides a technical solution: an explosion-proof limit switch, including an explosion-proof base plate 1, a connecting plate 2, a limit buckle 3, a positioning pin 4, an explosion-proof shell 5, a signal junction box 6, a connecting rod 7, a trigger rod 8, a connecting contact point 9, a circuit controller 10, a photoelectric sensor 11, a drive motor 12, a bevel gear 13, and a toothed ring 14.

[0034] Among them, the explosion-proof base plate 1 serves as the basic support component of the entire limit switch. There is a connecting plate 2 on each side of the explosion-proof base plate 1, and the explosion-proof base plate 1 is engaged with the explosion-proof housing 5. The circuit controller 10 is installed inside the explosion-proof base plate 1 by bolts, and the circuit controller 10 is used for controlling the explosion-proof limit switch and processing circuit signals.

[0035] A trapezoidal limit buckle 3 is installed on each side of the explosion-proof base plate 1. The limit buckle 3 has an opening that engages with the explosion-proof housing 5. The side wall of the limit buckle 3 is penetrated by a positioning pin 4, and one end of the positioning pin 4 is inserted into the explosion-proof housing 5. The connecting plate 2 has a mounting hole through which a bolt passes. A sealing element is provided at the connection between the explosion-proof base plate 1 and the explosion-proof housing 5. The explosion-proof housing 5 is penetrated and rotated by a connecting rod 7. A protruding column is provided at the connection between the explosion-proof housing 5 and the limit buckle 3. The protruding column of the explosion-proof housing 5 is penetrated by the positioning pin 4. The bottom end of the connecting rod 7 is rotatably connected to the surface of the explosion-proof base plate 1. The connecting rod 7 and the trigger rod 8 are an integral structure. One end of the trigger rod 8 contacts the connecting contact point 9 and transmits an electrical signal. The connecting contact point 9 is connected to the circuit controller 10 through a cable.

[0036] Referring to the attached diagrams in the instruction manual Figures 1-6 As shown, the explosion-proof base plate 1 is fixed to the equipment by bolts through the mounting holes on the two side connecting plates 2, ensuring that the explosion-proof base plate 1 is firmly connected to the equipment and will not loosen due to vibration or other factors generated during equipment operation.

[0037] Place the explosion-proof housing 5 on top of the explosion-proof base plate 1, so that the explosion-proof housing 5 and the limiting buckles 3 on both sides of the explosion-proof base plate 1 are initially engaged. An opening adapted to the explosion-proof housing 5 is opened in the limiting buckle 3. At this time, the positioning pin 4 is inserted through the side wall of the limiting buckle 3 and accurately inserted into the corresponding hole in the explosion-proof housing 5 to further fix the explosion-proof housing 5 and ensure that the two are tightly connected and accurately positioned.

[0038] Install the circuit controller 10 in the preset installation position inside the explosion-proof base plate 1 with bolts, ensuring that the installation is firm and the circuit connection is correct. Then embed the upper end of the photoelectric sensor 11 into the drive motor 12. Fix the signal junction box 6 in the rectangular openings on both sides of the explosion-proof housing 5. Connect the signal junction box 6, the circuit controller 10 and the photoelectric sensor 11 respectively by selecting the corresponding cables.

[0039] The explosion-proof housing 5 has rectangular openings on both sides, and a signal junction box 6 is fixed inside the rectangular opening of the explosion-proof housing 5. The signal junction box 6 is connected to the circuit controller 10 and the photoelectric sensor 11 through cables. The upper end of the photoelectric sensor 11 is embedded with a drive motor 12. The bevel gear 13 at the output end of the drive motor 12 meshes with the toothed ring 14. The toothed side of the toothed ring 14 is engaged with the trigger rod 8. The circuit controller 10 and the photoelectric sensor 11 are connected by electrical signals. The toothed ring 14 is rotatably connected inside the explosion-proof base plate 1, and the toothed ring 14 and the connecting rod 7 are arranged in a collar shape.

[0040] Referring to the attached diagrams in the instruction manual Figures 1-6 As shown, when the operating parts of the equipment approach or reach the preset limit position, the mechanical signal received by the signal junction box 6 is transmitted to the photoelectric sensor 11. The photoelectric sensor 11 transmits the signal quickly and accurately to the circuit controller 10 through the cable. After receiving the signal, the circuit controller 10 performs internal logic judgment and processing, and starts the drive motor 12. After the drive motor 12 is powered on, the bevel gear 13 at its output end begins to rotate. Since the bevel gear 13 is precisely meshed with the toothed ring 14, the rotation of the bevel gear 13 drives the toothed ring 14 to rotate smoothly within the explosion-proof base plate 1. When the toothed ring 14 rotates, the toothed side will drive the trigger rod 8 connected to it to rotate, so that one end of the trigger rod 8 accurately contacts the connecting contact point 9, realizing the reliable transmission of electrical signals. The connecting contact point 9 also transmits the signal to the circuit controller 10 through the cable. At this time, the circuit controller 10 processes and analyzes the signal again, and sends a control signal to the connected equipment through the signal junction box 6 according to the preset control logic, thereby realizing the limit control of the equipment movement.

[0041] When no signal transmission is required, the connecting rod 7 is connected via an external wrench or linkage structure. The operator manually rotates the connecting rod 7. Since the connecting rod 7 and the trigger rod 8 are an integral structure, the rotation of the connecting rod 7 will drive the trigger rod 8 on one side to rotate synchronously. After the trigger rod 8 rotates, it makes contact with the connecting contact point 9, thereby transmitting information to the circuit controller 10. After receiving the information, the circuit controller 10 processes it and sends a corresponding signal to the device connected to the signal junction box 6. By adding a backup operation plan, an auxiliary start-up plan is provided for the device under different conditions.

[0042] Working principle: When using this explosion-proof limit switch, the explosion-proof base plate 1 serves as the basic support component. The connecting plates 2 on both sides are fixed to the equipment requiring limit control by bolts through the mounting holes on them. The explosion-proof housing 5 is further fixed by the cooperation of the limit buckles 3 on both sides and the positioning pins 4. In actual use, when the equipment running part approaches or reaches the preset limit position, the mechanical signal received by the signal junction box 6 is transmitted to the photoelectric sensor 11. As it senses the corresponding signal change, it transmits the signal to the circuit controller 10 through the cable, starts the drive motor 12, and makes the bevel gear 13 at its output end start to rotate. Since the bevel gear 13 is meshed with the toothed ring 14, it drives the toothed ring 14 to rotate in the explosion-proof base plate 1, thereby driving the connected trigger rod 8. After the trigger rod 8 is activated, one end of it contacts the connecting contact point 9 to realize the transmission of electrical signal. The connecting contact point 9 also transmits the signal to the circuit controller 10 through the cable.

[0043] When no signal transmission is required, the device is connected to the connecting rod 7 via an external wrench or linkage structure. By rotating the connecting rod 7, the connecting rod 7 drives the trigger rod 8 on one side to rotate synchronously, so that the trigger rod 8 contacts the connecting contact point 9 to transmit information to the circuit controller 10. The circuit controller 10 then sends a signal to the device connected to the signal junction box 6, which increases the overall practicality.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof limit switch, comprising: An explosion-proof base plate (1) serves as the basic support component for the entire limit switch. There is a connecting plate (2) on each side of the explosion-proof base plate (1), and the explosion-proof base plate (1) is interlocked with the explosion-proof housing (5). A circuit controller (10) is installed inside the explosion-proof base plate (1) by bolts. The circuit controller (10) is used for controlling the explosion-proof limit switch and processing circuit signals. The features are as follows: a trapezoidal limiting buckle (3) is installed on each side of the explosion-proof base plate (1), and the limiting buckle (3) has an opening that engages with the explosion-proof shell (5). The side wall of the limiting buckle (3) is penetrated by a positioning pin (4), and one end of the positioning pin (4) is inserted into the explosion-proof shell (5). The connecting plate (2) has an installation hole through which a bolt passes. The explosion-proof housing (5) has rectangular openings on both sides, and a signal junction box (6) is fixed inside the rectangular opening of the explosion-proof housing (5). The signal junction box (6) is connected to the circuit controller (10) and the photoelectric sensor (11) respectively through cables. The photoelectric sensor (11) has a drive motor (12) embedded in its upper end. The bevel gear (13) at the output end of the drive motor (12) meshes with the toothless tooth ring (14), and the toothless side of the toothless tooth ring (14) is engaged with the trigger rod (8).

2. An explosion-proof limit switch according to claim 1, characterised in that: A sealing element is provided at the connection between the explosion-proof base plate (1) and the explosion-proof shell (5), and the explosion-proof shell (5) is penetrated and rotated by the connecting rod (7).

3. The explosion-proof limit switch of claim 1, wherein: The explosion-proof shell (5) is provided with a protruding column at the connection between it and the limiting buckle (3), and the protruding column of the explosion-proof shell (5) is penetrated by the positioning pin (4).

4. The explosion-proof limit switch of claim 2, wherein: The bottom end of the connecting rod (7) is rotatably connected to the surface of the explosion-proof base plate (1), and the connecting rod (7) and the trigger rod (8) are an integral structure.

5. The explosion-proof limit switch of claim 1, wherein: One end of the trigger rod (8) contacts the connecting contact point (9) and transmits an electrical signal, and the connecting contact point (9) is connected to the circuit controller (10) through a cable.

6. The explosion-proof limit switch of claim 1, wherein: The circuit controller (10) and the photoelectric sensor (11) are electrically connected.

7. The explosion-proof limit switch of claim 1, wherein: The toothed ring (14) is rotatably connected inside the explosion-proof base plate (1), and the toothed ring (14) and the connecting rod (7) are arranged in a ring shape.

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