Protective device for tensioning trolley of belt conveyor

Abstract

The utility model discloses a belt conveyor tensioning trolley protection device which comprises a tensioning limit switch, a return stroke limit switch, stop iron and a controller, the stop iron is installed on a tensioning trolley, the limit switch is arranged in the running direction of the trolley and connected with the controller, an anti-disengaging switch is additionally arranged outside the working stroke of the tensioning trolley, and the return stroke limit switch is connected with the controller. The anti-falling switch is connected with the trolley through a pull rope, so that the over-travel can be triggered; the anti-falling switch comprises a shell, a static contact plate, a movable contact plate, a signal line, a spring, a clamping mechanism, a guide rod and a pull rope wire buckle, one face of the movable contact plate is connected with the shell through the spring, the guide rod fixed to the other face extends out of the shell to be connected with a pull rope, and the two contact plates are provided with corresponding contacts and are connected with the signal line to the controller. The clamping mechanism is provided with a plurality of clamping positions for limiting the movable contact plate, and when the clamping mechanism is rotated, the movable contact plate is separated from the clamping positions and resets. The tensioning trolley protection device solves the problem that a limiting switch of an existing tensioning trolley protection device of the belt conveyor cannot keep a reliable, stable and effective working state.

Description

Technical Field

[0001] This utility model relates to the field of belt conveyor technology, and in particular to a protective device for the tensioning trolley of a belt conveyor. Background Technology

[0002] Belt conveyors are crucial material handling equipment in bulk cargo terminal operations, responsible for unloading bulk cargo such as ore and coal to the subsequent bulk cargo storage yard. The operation of a belt conveyor relies on the friction between the belt and the drive drum. To ensure optimal friction, a self-controlled hydraulic tensioning device is used to adjust the belt tension, with the tension force adjusted by the stroke of the tensioning trolley. In actual operation, belt conveyors frequently encounter issues such as starting with material, excessive belt tension leading to overtravel and derailment of the tensioning trolley, and wire rope breakage. The tensioning trolley protection device effectively addresses these potential risks. Its main function is to ensure that the belt drive equipment stops synchronously in the event of overtravel derailment or wire rope breakage, preventing damage to the hydraulic tensioning device structure and belt breakage. The effectiveness and reliability of the tensioning trolley protection device are of paramount importance.

[0003] Currently, the tensioning trolley is equipped with one limit switch each for tensioning and return travel. These limit switches are installed along the trolley's running track to detect the travel position of the tensioning trolley. However, this structure has the following problems: If the trolley is accidentally lifted during operation, the protective limit switch may not be able to effectively contact the limit switch, thus rendering the protection ineffective. Furthermore, the stop used by the current travel limit switch is relatively short. When the trolley reaches the limit switch position, due to inertia, the trolley will continue to move forward, causing the stop on the trolley to fail to effectively contact the swing arm of the travel limit switch, thus preventing the travel switch from maintaining a stable working state. In this situation, if the personnel fail to arrive on-site in time to confirm, and the monitoring screen shows normal operation, allowing the belt conveyor to be restarted, it may lead to a serious risk of damage to the belt conveyor. Utility Model Content

[0004] The purpose of this invention is to provide a protection device for the tensioning trolley of a belt conveyor, which can solve the problem that the limit switches of existing belt conveyor tensioning trolley protection devices cannot maintain a reliable, stable and effective working state.

[0005] To solve the above problems, the technical solution adopted by this utility model is as follows: This belt conveyor tensioning trolley protection device includes a tensioning limit switch, a return limit switch, a stop, and a controller. The stop is installed on the tensioning trolley. The tensioning limit switch and the return limit switch are installed along the trolley's travel direction and are electrically connected to the controller respectively. An anti-detachment switch is installed near the tensioning limit switch outside the working stroke of the tensioning trolley. The anti-detachment switch is connected to the tensioning trolley via a pull rope. The distance of the pull rope from the tensioning trolley's position at the trigger position of the tensioning limit switch to when it is taut and tensioned is the same as the working stroke distance. The anti-detachment switch includes a housing and a stationary contact plate, a moving contact plate, a first signal line, a second signal line, and a spring installed inside the housing. The device comprises a locking mechanism, a guide rod, and a pull cord buckle. The stationary contact plate is fixed inside the housing. One side of the moving contact plate is connected to the housing via a spring, and the other side is fixed with a guide rod extending out of the housing. The extended end of the guide rod is connected to a pull cord via the pull cord buckle. Corresponding contacts are provided on the surfaces of the stationary and moving contact plates. The stationary and moving contact plates are respectively connected to the first signal line and the second signal line. One end of the first signal line and the second signal line are respectively connected to the corresponding contact, and the other end extends out of the housing and is electrically connected to the controller. The locking mechanism has multiple locking positions that restrict the contact between the moving contact plate and the stationary contact plate. Rotating the locking mechanism causes the moving contact plate to disengage from the locking positions and reset.

[0006] In the above-mentioned technical solution of the belt conveyor tension trolley protection device, a more specific technical solution may be: the locking mechanism includes a rotating shaft, an arc-shaped ratchet, and a reset handle. The rotating shaft is rotatably connected to the housing, and multiple arc-shaped ratchets are arranged on the rotating shaft. The reset handle is installed at one end of the rotating shaft that extends out of the housing.

[0007] In some possible implementations, the tension limit switch and / or the return limit switch are two limit switches arranged vertically.

[0008] In some possible implementations, the stop is welded with a widened and elongated iron plate.

[0009] In some possible implementations, the total width of the stop and the iron plate ranges from 50 to 100 mm, and the total length ranges from 90 to 120 mm.

[0010] By adopting the above technical solution, this utility model has the following beneficial effects compared with the prior art:

[0011] 1. This protection device significantly improves the reliability and stability of protection. By adding an anti-detachment switch and a pull rope connection system, it forms a dual protection system in conjunction with the original tension / return limit switch. This precisely controls the trolley's travel range and immediately triggers the protection mechanism when the trolley unexpectedly deviates from its normal travel range. Its design not only enhances the accuracy of travel control but also enables rapid fault response via electrical signals, achieving immediate equipment shutdown and effectively reducing the risk of equipment damage and production interruption time. Furthermore, this protection device has a simple and reasonable structure and is easy to maintain.

[0012] 2. The structural design of the locking mechanism provides stable locking and prevents malfunctions. At the same time, it allows for easy manual reset of the moving contact plate, simplifying the reset process.

[0013] 3. Designing the tension limit switch and / or return limit switch as two limit switches, one above the other, reduces the risk of failure caused by a single limit switch failure and improves the accuracy of judging the trolley's travel position, significantly enhancing its detection accuracy and protection reliability under complex working conditions; at the same time, the setting of two limit switches, one above the other, facilitates debugging and maintenance, and operators can flexibly adjust their positions according to actual needs to adapt to different working environments and conditions. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the layout structure of the tensioning trolley protection device for this belt conveyor.

[0015] Figure 2 This is a top view of the tensioning system of a belt conveyor.

[0016] Figure 3 This is a schematic diagram of the anti-disconnect switch.

[0017] Figure 4 yes Figure 3 The right view.

[0018] Explanation of reference numerals: 1. Tensioning hydraulic cylinder; 2. Tensioning trolley; 3. Track; 4. Tensioning redirection position roller; 5. Return limit switch; 6. Stop; 7. Tensioning limit switch; 8. Pull rope; 9. Anti-derailment switch; 10. Tensioning winch; 11. Housing; 12. Stationary contact plate; 13. First signal line; 14. Rotating shaft; 15. Arc-shaped ratchet; 16. Reset handle; 17. Pull rope buckle; 18. Guide rod; 19. Second signal line; 20. Moving contact plate; 21. Spring. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 and Figure 2The belt conveyor tensioning trolley protection device shown mainly includes an anti-derailment switch 9, a tension limit switch 7, a return limit switch 5, a stop 6, and a controller. The controller is a PLC controller that controls the operation of the belt conveyor. The stop 6 is installed on the tensioning trolley 2, which is used to adjust the tension of the conveyor belt. The anti-derailment switch 9, tension limit switch 7, and return limit switch 5 are installed along the travel direction of the tensioning trolley 2 and are electrically connected to the PLC controller. To ensure the reciprocating linear travel of the tensioning trolley 2, a track 3 is usually provided, and a hydraulic tensioning device is used to drive the reciprocating linear motion of the tensioning trolley 2. The existing hydraulic tensioning device includes a tensioning hydraulic cylinder 1 and a tensioning winch 10. A track 3 is positioned between the tensioning hydraulic cylinder 1 and the tensioning redirecting roller 4. A tensioning limit switch 7 and a return limit switch 5 are mounted on the track 3. The tensioning limit switch 7 is close to the hydraulic tensioning device, and the return limit switch 5 is close to the tensioning redirecting roller 4. The distance between the tensioning limit switch 7 and the return limit switch 5 is the working stroke of the tensioning trolley 2. The trolley is within this safe range; exceeding this range requires stopping and adjustment. Preferably, the limit switches are mounted above the track 3, reducing the risk of malfunction due to material accumulation or water ingress, thus ensuring greater effectiveness. An anti-detachment switch 9 is positioned outside the working stroke of the tensioning trolley 2 and close to the tensioning limit switch 7. The anti-detachment switch 9 is connected to the tensioning trolley 2 via a pull rope 8. For ease of pulling, the anti-detachment switch 9 is centrally positioned between the two rails of the track 3. The distance from the tensioning trolley 2 at the trigger position of the tensioning limit switch 7 to the point of taut tension is the same as the length of the working stroke.

[0021] The tension limit switch 7 and / or the return limit switch 5 are two limit switches positioned vertically, providing a double limit function. The distance between the two limit switches is approximately 10cm, preventing the tension trolley 2 from being lifted by the belt, which would prevent the stop 6 from failing to trigger the limit switch. Furthermore, compared to a single limit switch, the double limit switch also prevents the failure of a single limit switch, resulting in a higher safety factor. The stop 6 is welded with a widened and lengthened iron plate. The total width of the stop 6 and the iron plate ranges from 50 to 100mm, and the total length ranges from 90 to 120mm, ensuring that the stop can still effectively trigger the swing arm of the travel limit switch when the trolley moves forward due to inertia.

[0022] like Figure 3 and Figure 4As shown, the anti-disengagement switch 9 includes a housing 11 and, installed within the housing 11, a stationary contact plate 12, a moving contact plate 20, a first signal line 13, a second signal line 19, a spring 21, a locking mechanism, a guide rod 18, and a pull cord buckle 17. The stationary contact plate 12 is fixed inside the housing 11. One side of the moving contact plate 20 is connected to the housing 11 via the spring 21, and the other side is fixed with a guide rod 18 extending out of the housing 11. The extended end of the guide rod 18 is connected to the pull cord 8 via the pull cord buckle 17. To ensure stable movement of the guide rod 18, the housing 11 has a guide hole for sliding cooperation with the guide rod 18, and also has lead holes for the first signal line 13 and the second signal line 19 to pass through the housing. Corresponding contacts are provided on the surfaces of the stationary contact plate 12 and the moving contact plate 20. These contacts are made of wear-resistant materials to ensure long-term reliability and stability. The stationary contact plate 12 and the moving contact plate 20 are respectively connected to the first signal line 13 and the second signal line 19. One end of the first signal line 13 and the second signal line 19 are respectively connected to the corresponding contact, and the other end extends out of the housing 11 and is electrically connected to the PLC controller. The locking mechanism has multiple locking positions that restrict the contact between the moving contact plate 20 and the stationary contact plate 12. The mechanism includes a rotating shaft 14, an arc-shaped ratchet 15, and a reset handle 16. The rotating shaft 14 is rotatably connected to the housing 11. Multiple arc-shaped ratchet 15s with a certain degree of elasticity are arranged on the rotating shaft 14. The reset handle 19 is installed at the end of the rotating shaft 14 that extends out of the housing 11. The design of the arc-shaped ratchet 15 can reduce the pulling resistance and make the moving contact plate 20 move more smoothly during the pulling process; at the same time, the reset handle 16 facilitates quick reset by the operator. Rotating the locking mechanism can disengage the moving contact plate 20 from the locking position and reset it, thereby realizing the cyclic use of the anti-disengagement switch 9.

[0023] The working principle of the tension trolley protection device for this belt conveyor is as follows: Under normal conditions, the spring 21 inside the anti-detachment switch 9 is in a pre-tensioned state, and the contact points of the moving contact plate 20 and the stationary contact plate 12 are tightly connected, forming a normally closed signal point. The tension trolley 2 runs within its normal working stroke, and the stop 6 does not trigger the limit switches (including the tension limit switch 7 and the return limit switch 5), and the belt runs normally. When the tension limit switch 7 detects that the tension trolley 2 has reached the tension limit position, or the return limit switch 5 detects that the trolley has returned to the return limit position, a signal is sent to the PLC controller, and the PLC controller controls the belt conveyor to stop according to the signal. Under abnormal conditions, when the tension trolley 2 overtravels or the winch wire rope breaks, the tension trolley 2 moves under the traction of the belt, the pull rope 8 is straightened and tightened, and the guide rod 18 pulls the moving contact plate 20 to overcome the elastic force of the spring 21, causing the moving contact plate 20 to separate from the stationary contact plate 12, the contact is broken, and a normally open signal point is formed. Upon receiving the normally open signal, the PLC controller immediately stops the belt conveyor to prevent equipment damage. After on-site personnel confirm that the tension trolley 2 is in a safe position, they rotate the reset handle 16 of the anti-disengagement switch 9, causing the moving contact plate 20 to disengage from the arc-shaped ratchet 15 of the locking mechanism. The spring 21 pulls the moving contact plate 20 back to its original position, re-engaging it with the stationary contact plate 12, restoring the normally closed signal point. After ensuring the trolley is in a safe operating state, the belt conveyor can be restarted.

Claims

1. A protective device for a belt conveyor tensioning trolley, comprising a tensioning limit switch, a return limit switch, a stop, and a controller, wherein the stop is mounted on the tensioning trolley, and the tensioning limit switch and the return limit switch are mounted along the trolley's travel direction and electrically connected to the controller, characterized in that: An anti-disengagement switch is installed near the tension limit switch outside the working stroke of the tensioning carriage. The anti-disengagement switch is connected to the tensioning carriage via a pull rope. The distance of the pull rope from the trigger position of the tension limit switch to the point where the carriage is taut is the same as the working stroke distance. The anti-disengagement switch includes a housing and a stationary contact plate, a moving contact plate, a first signal line, a second signal line, a spring, a locking mechanism, a guide rod, and a pull rope buckle installed inside the housing. The stationary contact plate is fixed inside the housing, and one side of the moving contact plate is connected to the housing via the spring, while the other side is fixed. A guide rod extends out of the housing, and the extended end of the guide rod is connected to the pull rope via the pull rope buckle. Corresponding contacts are provided on the surfaces of the stationary contact plate and the moving contact plate. The stationary contact plate and the moving contact plate are respectively connected to the first signal line and the second signal line. One end of the first signal line and the second signal line are respectively connected to the corresponding contact, and the other end extends out of the housing and is electrically connected to the controller. The locking mechanism has multiple locking positions that restrict the contact between the moving contact plate and the stationary contact plate. When the locking mechanism is rotated, the moving contact plate disengages from the locking position and resets.

2. The belt conveyor tensioning trolley protection device according to claim 1, characterized in that: The locking mechanism includes a rotating shaft, arc-shaped ratchet teeth, and a reset handle. The rotating shaft is rotatably connected to the housing, and multiple arc-shaped ratchet teeth are arranged on the rotating shaft. The reset handle is installed at the end of the rotating shaft that extends out of the housing.

3. The belt conveyor tensioning trolley protection device according to claim 1 or 2, characterized in that: The tension limit switch and / or the return limit switch are two limit switches set at the top and bottom.

4. The belt conveyor tensioning trolley protection device according to claim 3, characterized in that: The retaining block is welded with a wider and longer iron plate.

5. The belt conveyor tensioning trolley protection device according to claim 4, characterized in that: The total width of the stop and the iron plate ranges from 50 to 100 mm, and the total length ranges from 90 to 120 mm.

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