Heavy load telescopic fork with anti-loose locking structure

Abstract

The present application relates to the technical field of telescopic fork, and discloses a heavy-load telescopic fork with anti-loosening locking structure, which comprises two mounting rack plates, the two ends of the two mounting rack plates are fixedly provided with fixed forks, the fixed forks are slidably provided with middle forks, and the middle forks are slidably provided with upper telescopic forks. The present application is provided with an electric control plug-in locking structure composed of an electromagnet magnetic attraction linkage spring telescopic rod and a locking frame, which realizes telescopic fork limiting protection. When the telescopic fork is completely retracted and stored, the magnetic attraction drives the telescopic rod to plug in and lock, locks the relative positions of the forks at all levels, avoids the shaking and sliding of the forks during the transfer and movement of the equipment, and after the telescopic fork is extended and loaded, the multi-stage rigid locking can be completed again, the anti-loosening locking assembly is matched to eliminate the sliding assembly gap of the forks at all levels, the loosening and position deviation of the forks during heavy-load material taking are avoided, the transfer stability and the load positioning accuracy are taken into account, and the high-precision automatic material taking and placing operation is adapted.

Description

Technical Field

[0001] This invention relates to the field of telescopic fork technology, and in particular to a heavy-duty telescopic fork equipped with an anti-loosening locking structure. Background Technology

[0002] Heavy-duty telescopic forks are heavy-duty telescopic material handling mechanisms used in automated stacker cranes, heavy-duty AGVs, and automated warehouses. The industry standard is that a rated load of ≥1t is considered heavy-duty, with mainstream specifications ranging from 2t to 10t. Customized ultra-heavy-duty forks can reach 50t. They are used for storing and retrieving heavy molds, steel coils, castings, vehicle parts, and heavy pallets.

[0003] In the long-term continuous operation of heavy-duty telescopic forks in automated warehouses, heavy mold storage, steel raw material warehouses, etc., when the forks extend to the target shelf position and are in place to support heavy pallets, castings or stamping dies, the existing heavy-duty telescopic forks rely only on servo motor brakes or simple limit structures to constrain the position of the multi-level nested forks, lacking a rigid mechanical locking limit structure.

[0004] Under the combined effects of multiple factors, such as uneven loading of goods, inertial impact from the start and stop of the stacker crane, long-term wear of guide rail rollers resulting in clearance, and slight loosening of transmission fasteners due to alternating vibration, the middle and upper forks of the telescopic fork are prone to slight slippage and movement along the telescopic direction. The positioning accuracy of the fork bearing end continues to deviate, which not only causes misalignment of the load-bearing points of the goods and shift of the pallet's center of gravity, reducing the stability of heavy-load goods, but also easily leads to malfunctions such as goods tilting and collision with the rack beams.

[0005] Therefore, a heavy-duty telescopic fork with an anti-loosening locking structure needs to be designed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a heavy-duty telescopic fork with an anti-loosening locking structure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A heavy-duty telescopic fork with an anti-loosening locking structure includes two mounting plates. Fixed forks are fixedly mounted on both ends of the two mounting plates. A middle fork is slidably mounted on the fixed fork. An upper telescopic fork is slidably mounted on the middle fork. Two sets of anti-loosening locking components for locking the telescopic fork in place are symmetrically arranged on the mounting plates, the middle fork, and the upper telescopic fork. Anti-fall plates are provided at both ends of the upper telescopic fork. Tensioning structures for pulling the extended end of the upper telescopic fork are provided on both sides of the mounting plates located on the fixed fork.

[0009] The anti-loosening locking assembly includes a vertical plate fixedly installed on the top surface of the mounting plate, connecting plates fixedly installed at both ends of the intermediate fork, spring telescopic rods fixedly installed at both ends of the upper telescopic fork and the bottom side of the connecting plate, and locking frames corresponding to the spring telescopic rods fixedly installed on the bottom side of the vertical plate and the upper side of the connecting plate.

[0010] As a preferred embodiment of the present invention, the side of the fixed fork is provided with a driving structure for driving the intermediate fork and the upper telescopic fork.

[0011] As a preferred embodiment of the present invention, positioning sensors are fixedly installed on the top and bottom surfaces of both ends of the intermediate fork, and sensing plates adapted to the positioning sensors are fixedly installed on the top surfaces of both ends of the fixed fork and the bottom surfaces of both ends of the upper telescopic fork.

[0012] As a preferred embodiment of the present invention, the anti-loosening locking assembly further includes a magnetic sheet fixedly installed at the telescopic end of the spring telescopic rod, the locking frame is U-shaped, and the side of the locking frame has an insertion port corresponding to the telescopic end of the spring telescopic rod. Electromagnets are fixedly installed on the upright plate and the connecting plate at positions corresponding to the insertion ports.

[0013] As a preferred embodiment of the present invention, the connecting plate is configured as a T-shape, and the vertical part of the connecting plate is located between the intermediate fork and the upright plate.

[0014] As a preferred embodiment of the present invention, the electromagnet and the socket are coaxially arranged, and both the electromagnet and the positioning sensor are electrically connected to an external controller.

[0015] As a preferred embodiment of the present invention, the tensioning structure includes a fixed shell fixedly installed on the upper side of the upright plate. A reel is rotatably installed on the inner wall of the fixed shell. A tensioning cable is provided on the inner side of the reel. The pulling end of the tensioning cable passes through the outer wall of the fixed shell and is fixedly connected to the side of the fall arrestor plate. A torsion spring is fitted on the end of the reel, and the two ends of the torsion spring are fixedly connected to the reel and the fixed shell, respectively. A clearance component for the fall arrestor plate to make way is provided on the upright plate and the fall arrestor plate.

[0016] As a preferred embodiment of the present invention, the clearance component includes two mounting slots opened at the end of the upper telescopic fork. Mounting rods are inserted into the inner wall of the mounting slots. One end of the two mounting rods located outside the mounting slots is fixedly connected to the side of the fall arrestor plate. A positioning slot is opened on the side of the fall arrestor plate. A bracket is fixedly installed on the side of the upright plate. A positioning rod that engages with the positioning slot is fixedly installed at the end of the bracket away from the upright plate.

[0017] As a preferred embodiment of the present invention, the inner walls of both the positioning groove and the mounting groove are provided with a number of evenly distributed protrusions.

[0018] The present invention has the following beneficial effects:

[0019] 1. In this invention, an electrically controlled plug-in locking structure composed of an electromagnet magnetically attracted spring telescopic rod and a locking frame is used to achieve limit protection for the telescopic fork. When the telescopic fork is fully retracted, the magnetically driven telescopic rod is plugged in and locked to lock the relative positions of each fork body, preventing the fork body from shaking and slipping during equipment transfer. After the telescopic fork extends outward and is in place with the load, it can complete the multi-level rigid locking a second time. In conjunction with the anti-loosening locking component, it eliminates the slippage and assembly gaps of each fork body, and prevents the fork body from loosening and shifting during heavy-load material handling. It takes into account both transfer stability and load positioning accuracy, and is suitable for high-precision automated material handling operations.

[0020] 2. In this invention, when the upper telescopic fork is extended for heavy-duty operation, the taut steel cable continuously pulls the extended end of the fork body to counteract the sag deflection and overturning moment caused by the weight of the goods and the fork body itself, and avoid the overloaded end of the cantilever from falling and deforming. During the retraction process, the torsion spring automatically winds up the steel cable, and at the same time, the positioning rod limits and separates the anti-fall plate to eliminate mechanical interference during retraction. It takes into account both heavy-duty anti-fall protection and the smoothness of the fork body's full stroke retraction, and is suitable for high-load long-term reciprocating operation.

[0021] 3. In this invention, the fixed fork, intermediate fork, and upper telescopic fork are driven by a drive structure to extend and retract in multiple stages, which can independently adjust the working span and extension stroke, flexibly adapt to material handling operations of different sizes and strokes. The automated adjustment is convenient and efficient. At the same time, it integrates mechanical locking, electrical control plug-in limit, and steel cable tension anti-fall triple protection to form a composite protection structure that prevents loosening, displacement, falling, and shaking. This improves the overall structural rigidity of the multi-stage fork body, reduces operational deformation and structural wear, reduces the probability of equipment failure, and extends the service life of the whole machine. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a heavy-duty telescopic fork with an anti-loosening locking structure proposed in this invention. Figure 2 This is a schematic diagram of the fixed fork and intermediate fork structure of a heavy-duty telescopic fork with an anti-loosening locking structure proposed in this invention. Figure 3 This is an exploded structural diagram of the connecting plate of a heavy-duty telescopic fork with an anti-loosening locking structure proposed in this invention. Figure 4 This is a schematic diagram of the upper telescopic fork structure of a heavy-duty telescopic fork with an anti-loosening locking structure proposed in this invention. Figure 5 for Figure 4 Enlarged structural diagram at point A in the middle; Figure 6 This is a schematic diagram of the upright plate structure of a heavy-duty telescopic fork with an anti-loosening locking structure proposed in this invention.

[0023] In the diagram: 1. Mounting frame; 2. Fixed fork; 21. Intermediate fork; 22. Upper telescopic fork; 23. Drive structure; 24. Positioning sensor; 25. Sensor plate; 3. Anti-loosening locking assembly; 31. Vertical plate; 32. Connecting plate; 33. Spring telescopic rod; 34. Magnetic plate; 35. Locking frame; 36. Socket; 37. Electromagnet; 4. Fall arrestor; 5. Tensioning structure; 51. Fixing shell; 52. Reel; 53. Tensioning cable; 54. Torsion spring; 6. Clearance component; 61. Mounting slot; 62. Mounting rod; 63. Positioning slot; 64. Bracket; 65. Positioning rod. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] Example 1: This example discloses a heavy-duty telescopic fork equipped with an anti-loosening locking structure. (Refer to...) Figure 1-6 The system includes two mounting plates 1, with fixed forks 2 fixedly mounted at both ends of the mounting plates 1. A middle fork 21 is slidably mounted on the fixed fork 2, and an upper telescopic fork 22 is slidably mounted on the middle fork 21. A drive structure 23 for driving the middle fork 21 and the upper telescopic fork 22 is provided on the side of the fixed fork 2. A positioning sensor 24 is fixedly mounted on the top and bottom surfaces of both ends of the middle fork 21. A sensing plate 25 adapted to the positioning sensor 24 is fixedly mounted on the top surfaces of both ends of the fixed fork 2 and the bottom surfaces of both ends of the upper telescopic fork 22. Two sets of anti-loosening locking components 3 for locking the telescopic fork in position are symmetrically arranged on the mounting plates 1, the middle fork 21, and the upper telescopic fork 22. Anti-fall plates 4 are provided at both ends of the upper telescopic fork 22. A tensioning structure 5 for pulling the extended end of the upper telescopic fork 22 is provided on both sides of the mounting plates 1 located on the fixed fork 2.

[0026] The implementation principle of this embodiment is as follows:

[0027] During actual operation, the staff first assembles and fixes the two sets of mounting plates 1 onto the drive base, so that the drive base can support the entire telescopic fork frame structure and drive it to complete the overall displacement and movement, realizing flexible adjustment of the working position; when it is necessary to adjust the telescopic span to adapt to different cargo sizes and picking and placing strokes, the staff activates the drive structure 23 on the side of the fixed fork 2, and the drive structure 23 outputs a stable driving force to drive the middle fork 21 and the upper telescopic fork 22 to slide relative to each other along the sliding track of the fixed fork 2, realizing multi-level synchronous telescopic adjustment. Through the progressive extension or retraction of the middle fork 21 and the upper telescopic fork 22 to both sides, the overall working span and extension stroke of the telescopic fork frame can be flexibly changed to adapt to the material picking and feeding operation requirements of different working conditions. The overall adjustment has a high degree of automation and is convenient and flexible to operate.

[0028] When the intermediate fork 21 and the upper telescopic fork 22 are telescopically moved to the preset working position, the anti-loosening locking components 3 installed on the mounting plate 1, the intermediate fork 21 and the upper telescopic fork 22 are simultaneously activated to lock and fix the multi-stage telescopic sliding structure mechanically, effectively eliminating the assembly gap between each fork body, preventing the upper telescopic fork 22 from spontaneously sliding, loosening and shifting or shifting position after being heavily loaded with goods or retracted and reset, and ensuring the accuracy and stability of the telescopic fork frame's working position;

[0029] When the upper telescopic fork 22 extends outward for heavy-load operation, the anti-fall plate 4 at the end of the upper telescopic fork 22 can work in conjunction with the tensioning structure 5 on both sides of the mounting plate 1. The tensioning structure 5 forms a continuous and stable tensioning force on the extended end of the upper telescopic fork 22, effectively counteracting the drooping deflection and overturning moment generated by the cantilever extension, and reducing structural deformation. Combined with the rigid locking effect of the anti-loosening locking component 3 and the flexible tensioning effect of the tensioning structure 5, a composite protection system of double locking, anti-fall, anti-loosening, and anti-deviation is formed, which improves the structural rigidity and overall reliability of the multi-stage telescopic fork under heavy-load conditions, and ensures that the equipment is stable, safe, and durable during long-term, high-load reciprocating telescopic operation.

[0030] Example 2: Based on Example 1, this example discloses a heavy-duty telescopic fork equipped with an anti-loosening locking structure, such as... Figure 1 , Figure 3 and Figure 5As shown, the anti-loosening locking assembly 3 includes a vertical plate 31 fixedly installed on the top surface of the mounting plate 1. Connecting plates 32 are fixedly installed at both ends of the intermediate fork 21. The connecting plates 32 are T-shaped, and the vertical part of the connecting plates 32 is located between the intermediate fork 21 and the vertical plate 31. Spring telescopic rods 33 are fixedly installed at both ends of the upper telescopic fork 22 and the bottom side of the connecting plate 32. Magnets 34 are fixedly installed at the telescopic ends of the spring telescopic rods 33. Locking frames 35 corresponding to the spring telescopic rods 33 are fixedly installed on the bottom side of the vertical plate 31 and the upper side of the connecting plate 32. The locking frames 35 are U-shaped, and the sides of the locking frames 35 have slots 36 corresponding to the telescopic ends of the spring telescopic rods 33. Electromagnets 37 are fixedly installed on the vertical plate 31 and the connecting plate 32 at positions corresponding to the slots 36. The electromagnets 37 and the slots 36 are coaxially arranged. The electromagnets 37 and the positioning sensor 24 are electrically connected to an external controller.

[0031] The implementation principle of this embodiment is as follows:

[0032] When the heavy-duty telescopic fork is in its fully retracted state, the spring telescopic rods 33 on the T-shaped connecting plates 32 at both ends of the intermediate fork 21 are precisely aligned with the locking frames 35 on the side of the upright plate 31 on the mounting bracket plate 1. At the same time, the spring telescopic rods 33 at both ends of the upper telescopic fork 22 correspond one-to-one with the locking frames 35 on the upper part of the connecting plate 32. Each telescopic rod is in a coaxial alignment with the socket 36. At this time, the positioning sensor 24 and the sensing plate 25 are aligned and send a signal to control the electromagnet 37 to be energized through the control system. The working principle and connection method of the positioning sensor 24, the sensing plate 25 and the electromagnet 37 are existing mature technologies. The technology will not be elaborated on here. Electromagnet 37 generates magnetism, and the relative magnetic poles of electromagnet 37 and magnetic plate 34 at the end of spring telescopic rod 33 are opposite. Relying on the magnetic force of opposite magnetic poles attracting each other, spring telescopic rod 33 is pulled to overcome its initial contraction elasticity and automatically extend, so that the end of telescopic rod and magnetic plate 34 are accurately inserted into the slot 36 on the side of locking frame 35. Through rigid insertion and limiting method, the position locking between intermediate fork 21 and mounting plate 1, and between upper telescopic fork 22 and intermediate fork 21 are respectively completed, effectively locking the telescopic fork in the retracted state and preventing spontaneous slippage and shaking of each fork body during equipment movement;

[0033] When cargo handling operations are required and the telescopic forks extend outward, the electromagnet 37 is first de-energized and demagnetized, completely eliminating the magnetic attraction. The spring telescopic rod 33 is no longer magnetically pulled and automatically shortens and retracts under its own elastic restoring force, causing the end of the telescopic rod to completely disengage from the slot 36 of the locking frame 35, releasing the locking limit between each level of the fork. At this time, the middle fork 21 and the upper telescopic fork 22 can slide smoothly along the fixed fork 2, completing the outward extension action normally. When the telescopic fork extends to the preset cargo-bearing position and is fully in place, the spring telescopic rods... The telescopic rod 33 is precisely aligned with the corresponding locking frame 35 and socket 36. The control system then controls the electromagnet 37 to be energized and magnetized. Through magnetic attraction, the spring telescopic rod 33 is extended and inserted into the socket 36, re-establishing the rigid insertion and locking structure between the multi-level forks. By locking and fixing the telescopic forks in the extended and positioned state in all directions, the potential for loosening, slippage, and displacement of each level of fork under heavy load conditions is completely eliminated. This ensures that the structure is stable and the force is evenly distributed when the telescopic forks are extended to carry goods, thereby improving the safety of heavy-load operations and the accuracy of equipment operation.

[0034] Example 3: Based on Example 1, this example discloses a heavy-duty telescopic fork equipped with an anti-loosening locking structure, such as... Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the tensioning structure 5 includes a fixed shell 51 fixedly installed on the upper side of the upright plate 31. A reel 52 is rotatably installed on the inner wall of the fixed shell 51. A tensioning steel cable 53 is provided on the inner side of the reel 52. The pulling end of the tensioning steel cable 53 passes through the outer wall of the fixed shell 51 and is fixedly connected to the side of the fall arresting plate 4. A torsion spring 54 is fitted on the end of the reel 52, and the two ends of the torsion spring 54 are fixedly connected to the reel 52 and the fixed shell 51 respectively. A clearance component 6 for the fall arresting plate 4 to make way is provided on the fall arresting plate 4 and the upright plate 31.

[0035] The clearance component 6 includes two mounting slots 61 opened at the end of the upper telescopic fork 22. Mounting rods 62 are inserted into the inner wall of the mounting slots 61. The two mounting rods 62 are fixedly connected to the side of the anti-fall plate 4 at one end located outside the mounting slots 61. The side of the anti-fall plate 4 is provided with a positioning slot 63. A bracket 64 is fixedly installed on the side of the upright plate 31. A positioning rod 65 that engages with the positioning slot 63 is fixedly installed at the end of the bracket 64 away from the upright plate 31. The inner walls of the positioning slot 63 and the mounting slot 61 are provided with several evenly distributed protrusions.

[0036] The implementation principle of this embodiment is as follows:

[0037] When the entire heavy-duty telescopic fork is in extended operation and carrying cargo, the overall structural form of the heavy-duty telescopic fork is as follows: Figure 1As shown, under this working condition, the tensioning steel cable 53 wound and stored inside the reel 52 extends outward synchronously with the upper telescopic fork 22, reaching the fully pulled-out and released state. The steel cable is taut throughout the gap between the reel 52 and the anti-fall plate 4, without any slack, bending, or deviation, and always maintains a taut and stressed state. Relying on the axial tension of the taut tensioning steel cable 53, the upper telescopic fork 22 is pulled and limited from the end to the suspended extension end, which counteracts the downward tilting and falling moment generated by the weight of the goods and the self-overlapping of the fork, ensuring the stability of the fork in the cargo-carrying operation and the structural safety.

[0038] Throughout the entire process of the heavy-duty telescopic fork completing the loading operation and performing the retraction and reset action, the energy storage torsion spring 54 built into the reel 52 continuously releases the pre-tensioning force. Relying on the rebound driving force of the torsion spring 54, the reel 52 is driven to rotate in a directional and uniform speed. Relying on the reverse torque of the reel 52, the exposed tension cable 53 is automatically wound up. Matching the retraction stroke of the telescopic fork 22, the cable is synchronously stored, ensuring that the cable storage stroke is synchronized with the fork retraction stroke.

[0039] Before the upper telescopic fork 22 retracts into place and fits against the reference position, the positioning rod 65 pre-installed at the end of the bracket 64 is precisely aligned and inserted into the special positioning groove 63 opened on the side of the fall arrestor plate 4 to complete the locking and positioning of the fall arrestor plate 4, fix the overall position of the fall arrestor plate 4, and restrict the fall arrestor plate 4 from continuing to retract synchronously with the upper telescopic fork 22. When the upper telescopic fork 22 continues to retract and move, the mounting rod 62 fixed on the side wall of the fall arrestor plate 4 slides smoothly out along the groove trajectory of the mounting groove 61, releases the plugging relationship between the fall arrestor plate 4 and the upper telescopic fork 22, realizes the independent limiting of the fall arrestor plate 4 and the separate retraction of the fork body, eliminates the mechanical interference of the fall arrestor plate 4 structure on the retraction stroke of the intermediate fork 21 and the upper telescopic fork 22, and ensures that the secondary fork body can retract without obstacles and fit against the reference position of the frame to complete the full stroke positioning and reset.

[0040] When the equipment is restarted for the second time and put into loading operation, and the upper telescopic fork 22 extends outward again, the mounting groove 61 on the upper telescopic fork 22 moves forward and aligns synchronously. The fixed mounting rod 62 on the side wall of the fall arrestor 4 is inserted into the mounting groove 61, automatically completing the insertion and assembly, restoring the connection structure between the fall arrestor 4 and the upper telescopic fork 22, and reconstructing the end fall arrestor limit structure. At the same time, during the outward extension process of the upper telescopic fork 22, it directly drags and pulls the tension cable 53 forward, overcoming the pre-tension of the torsion spring 54 to drive the reel 52 to rotate forward and unwind, gradually releasing the steel cable inside the reel 52, restoring the steel cable between the reel 52 and the fall arrestor 4 to a taut and stressed state, resetting the fall arrestor tension protection structure, and restoring the entire mechanism to the standard working condition of extended loading, which is capable of heavy-load fall arrest operation. The entire process of telescopic loading and retraction reset is completed cyclically.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A heavy-duty telescopic fork with an anti-loosening locking structure, comprising two mounting plates (1), each end of which is fixedly mounted with a fixed fork (2), a middle fork (21) is slidably mounted on the fixed fork (2), and an upper telescopic fork (22) is slidably mounted on the middle fork (21), characterized in that, Two sets of anti-loosening locking components (3) for locking the telescopic fork in place are symmetrically arranged on the mounting plate (1), the intermediate fork (21) and the upper telescopic fork (22). Anti-fall plates (4) are provided at both ends of the upper telescopic fork (22). Tensioning structures (5) for pulling the extended end of the upper telescopic fork (22) are provided on both sides of the mounting plate (1) located on the fixed fork (2). The anti-loosening locking assembly (3) includes a vertical plate (31) fixedly installed on the top surface of the mounting plate (1), connecting plates (32) fixedly installed at both ends of the intermediate fork (21), spring telescopic rods (33) fixedly installed at both ends of the upper telescopic fork (22) and the bottom side of the connecting plate (32), and locking frames (35) corresponding to the spring telescopic rods (33) fixedly installed on the bottom side of the vertical plate (31) and the upper side of the connecting plate (32).

2. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 1, characterized in that, The side of the fixed fork (2) is provided with a drive structure (23) for driving the intermediate fork (21) and the upper telescopic fork (22).

3. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 1, characterized in that, The top and bottom surfaces of both ends of the intermediate fork (21) are fixedly equipped with positioning sensors (24), and the top surfaces of both ends of the fixed fork (2) and the bottom surfaces of both ends of the upper telescopic fork (22) are fixedly equipped with sensing plates (25) adapted to the positioning sensors (24).

4. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 3, characterized in that, The anti-loosening locking assembly (3) also includes a magnetic sheet (34) fixedly installed at the telescopic end of the spring telescopic rod (33). The locking frame (35) is U-shaped. The side of the locking frame (35) is provided with an insertion port (36) corresponding to the telescopic end of the spring telescopic rod (33). The upright plate (31) and the connecting plate (32) are both fixedly installed with electromagnets (37) at positions corresponding to the insertion port (36).

5. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 4, characterized in that, The connecting plate (32) is T-shaped, and the vertical part of the connecting plate (32) is located between the intermediate fork (21) and the upright plate (31).

6. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 4, characterized in that, The electromagnet (37) and the socket (36) are coaxially arranged, and the electromagnet (37) and the positioning sensor (24) are both electrically connected to the external controller.

7. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 1, characterized in that, The tensioning structure (5) includes a fixed shell (51) fixedly installed on the upper side of the upright plate (31). A reel (52) is rotatably installed on the inner wall of the fixed shell (51). A tensioning cable (53) is provided on the inner side of the reel (52). The pulling end of the tensioning cable (53) passes through the outer wall of the fixed shell (51) and is fixedly connected to the side of the fall arrestor plate (4). A torsion spring (54) is fitted on the end of the reel (52). The two ends of the torsion spring (54) are fixedly connected to the reel (52) and the fixed shell (51) respectively. A clearance component (6) for the fall arrestor plate (4) to make way is provided on the fall arrestor plate (4) and the upright plate (31).

8. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 7, characterized in that, The clearance component (6) includes two mounting slots (61) opened at the end of the upper telescopic fork (22). Mounting rods (62) are inserted into the inner wall of the mounting slots (61). The two mounting rods (62) are fixedly connected to the side of the anti-fall plate (4) at one end outside the mounting slots (61). The side of the anti-fall plate (4) is provided with a positioning slot (63). A bracket (64) is fixedly installed on the side of the upright plate (31). A positioning rod (65) that engages with the positioning slot (63) is fixedly installed at the end of the bracket (64) away from the upright plate (31).

9. A heavy-duty telescopic fork with an anti-loosening locking structure according to claim 8, characterized in that, The inner walls of the positioning groove (63) and the mounting groove (61) are provided with a number of evenly distributed protrusions.

Images