Torque-adjustable fan-shaped shell grab bucket

Abstract

The utility model discloses a fan-shaped shell grab bucket with adjustable torque. Belongs to the technical field of grab buckets and comprises a stand column and two grab bucket bodies, a hinge rod is fixedly arranged on the upper end face of each grab bucket body, the top end of each hinge rod is rotationally connected with the stand column, and two hydraulic telescopic rods are hinged to the outer surface of the stand column. When the torque of the grab bucket body needs to be adjusted, firstly, the hinged shaft for hinging the hydraulic telescopic rod and the force rod is pulled out, so that the output end of the hydraulic telescopic rod is separated from the force rod; then the angle of the force rod relative to the grab bucket body is adjusted through the force rod angle adjusting device; when the force rods rotate with the inner ends of the force rods as points and the outer ends of the two force rods move away from each other, the linear distance between the outer ends of the force rods and the top ends of the hinge rods is increased, the hydraulic telescopic rods control the torque of the grab bucket body to be increased, and then output rods of the hydraulic telescopic rods and the force rods are hinged together; the purpose of adjusting the opening and closing moment of the grab bucket body according to needs is achieved.

Description

Technical Field

[0001] This utility model belongs to the technical field of grabs, and particularly relates to a fan-shaped shell grab with adjustable torque. Background Technology

[0002] A grab bucket is a specialized tool used by cranes to grab dry bulk goods, including coal, grain, and nickel ore. Nickel ore is a highly viscous loess mud containing a large amount of moisture. The torque control parameters of a crane grab bucket are used to control its handling capacity and workload. These parameters include handling torque, gripping torque, and opening / closing torque. Under different scenarios and work tasks, the torque control parameters need to be adjusted appropriately to meet the material handling requirements.

[0003] For example, the opening and closing torque is adjusted according to the characteristics of different bulk materials. For instance, the opening and closing torques for coal and grain need to be different. This is because when the grab bucket comes into contact with the bulk material pile, the blade 12 of the grab bucket enters the pile to grab the material when the two grab buckets are closed. The torque required for the blade 12 of the grab bucket to enter different material piles is different. For example, the torque required to enter the coal pile is different from that required to enter the grain pile. The torque required for the blade 12 of the grab bucket to enter the coal pile is greater than that required to enter the grain pile. The torque required for the blade 12 of the grab bucket to enter the nickel ore pile is between that required for coal and grain. Currently, the opening and closing torque of the grab bucket is not convenient to adjust because the hinge point between the drive unit and the grab bucket is fixed.

[0004] A search revealed that patent number CN221878218U provides an excavator grab bucket. A connecting block 106 is fixedly connected to the top surface of the first grab bucket 120, and a rotating plate 107 is rotatably connected to the inner side of the connecting block 106. The top surface of the rotating plate 107 is fixedly connected to the bottom surface of the hydraulic rod 104. In the above solution, the hinge point between the hydraulic rod 104 and the grab bucket 120 is fixed, making it inconvenient to adjust the opening and closing torque of the grab bucket. Utility Model Content

[0005] The purpose of this invention is to provide a sector-shaped shell grab with adjustable torque, which has the advantage of conveniently adjusting the opening and closing torque of the grab and effectively solves the problem of inconvenience in adjusting the opening and closing torque of the grab in the prior art.

[0006] This utility model adopts the following technical solution: a torque-adjustable fan-shaped shell grab bucket, including a column and two grab bucket bodies. Each grab bucket body has a hinge rod fixedly installed on its upper end surface. The top end of each hinge rod is rotatably connected to the column. Two hydraulic telescopic rods are hinged to the outer surface of the column. The output end of each hydraulic telescopic rod is hinged to a force rod. The bottom end of each force rod is fixedly installed to the corresponding grab bucket body. A force rod angle adjustment device is provided between the force rod and the corresponding grab bucket body. The force rod angle adjustment device is used to adjust the angle between the force rod and the grab bucket body.

[0007] Furthermore, a fixing block is fixedly installed at the bottom of the column, and two hinge rods are fixed on each grab bucket body, and are arranged in the front-to-back direction on the upper end face of the grab bucket body. The top end of the front hinge rod is hinged to the front side of the fixing block, and the top end of the rear hinge rod is hinged to the rear side of the fixing block.

[0008] Furthermore, the lever angle adjustment device includes a fixed shaft fixedly mounted at the top of the lever, which is rotatably connected to the grab bucket body. It also includes an adjusting gear coaxially fixed on the fixed shaft. Two locking levers are hinged to the grab bucket body above the adjusting gear. The two locking levers are symmetrically arranged left and right with respect to the adjusting gear. A pressure spring is fixedly mounted on the outer side of each locking lever, and the outer ends of the pressure springs are fixedly mounted to the grab bucket body. The pressure springs constantly push the outer ends of the locking levers to move closer together, so that the outer ends of each locking lever are engaged in the adjusting gear. An unlocking device is provided between the two locking levers. The unlocking device is used to push the outer end of either locking lever out of the adjusting gear. When the unlocking device is in its initial position, the outer ends of both locking levers are engaged between the teeth of the adjusting gear.

[0009] Furthermore, the unlocking device includes a trapezoidal block. When the unlocking device is in the initial position, the upper and lower sides of the trapezoidal block are perpendicular to the line of symmetry between the two locking rods, and the inner side of each locking rod is in contact with the corresponding side of the trapezoidal block. At this time, the outer ends of the two locking rods are located between the teeth of the adjusting gear. A rotating shaft is fixedly installed inside the trapezoidal block, and the rotating shaft is rotatably connected to the grab bucket body.

[0010] Furthermore, a rotation space is provided on the grab body at a position corresponding to the fixed shaft; an accommodating space is provided on the inner wall of the rotation space, the adjusting gear is located in the accommodating space, and a hinge space communicating with the accommodating space is provided on the inner wall of the rotation space located above the accommodating space. Both locking rods are located in the hinge space, and the outer ends of both pressure springs are fixedly set to the grab body through the inner wall of the hinge space.

[0011] Furthermore, the grab body has an operating space, and the rotation axis of the trapezoidal block extends rearward into the operating space and is fixedly equipped with a lever.

[0012] Furthermore, limit blocks are fixedly installed on both sides of the inner wall of the operating space.

[0013] Furthermore, a locking block is engaged within the operating space, and a locking block with a lever clearance groove and a limiting block clearance groove are provided on the side of the locking block that is close to the lever; the lever is located in the lever clearance groove, and the limiting block is located in the limiting block clearance groove; the lever clearance groove keeps the lever in a vertical state at all times.

[0014] Furthermore, a fixing plate is fixedly installed on the outer side of the grab block, and the fixing plate is fixedly installed to the grab body by bolts.

[0015] Furthermore, each of the hinge rods is fixedly equipped with a synchronous gear at its top end, and two synchronous gears on the same side mesh with each other.

[0016] I. This utility model, by setting up a hydraulic telescopic rod, a lever, and a lever angle adjustment device, allows for the adjustment of the grab bucket body's torque when necessary. First, the hinge shaft connecting the hydraulic telescopic rod and the lever is pulled out, disengaging the output end of the hydraulic telescopic rod from the lever. Then, the lever angle adjustment device adjusts the angle of the lever relative to the grab bucket body. When the lever rotates around its inner end, causing the outer ends of the two levers to move away from each other, the linear distance between the outer end of the lever and the top of the hinge rod increases, increasing the torque of the hydraulic telescopic rod controlling the grab bucket body. Finally, the output rod of the hydraulic telescopic rod is hinged to the lever, achieving the purpose of adjusting the opening and closing torque of the grab bucket body as needed.

[0017] II. This utility model, by setting an adjusting gear, a locking rod, a pressure spring, and a trapezoidal block, allows the trapezoidal block to be rotated clockwise when the angle of the lever needs to be adjusted. The right side of the trapezoidal block moves downward away from the right locking rod, while the left side moves upward, forcing the left locking rod to rotate clockwise. This causes the outer end of the left locking rod to disengage from the teeth of the adjusting gear. At this time, the adjusting gear can rotate clockwise, which in turn can rotate the lever clockwise, thus achieving the purpose of adjusting the angle of the lever relative to the grab bucket body. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0019] Figure 2 This is a front view structural diagram of the two grab bucket bodies of this utility model in the closed state;

[0020] Figure 3 This is a front view structural diagram of the two grab bucket bodies of this utility model in the open state;

[0021] Figure 4 This is a three-dimensional structural diagram of the grab bucket body in this utility model;

[0022] Figure 5 This is a schematic diagram of the internal three-dimensional structure of the grab bucket body in this utility model;

[0023] Figure 6 In this utility model Figure 5 Enlarged schematic diagram of the structure at point A in the diagram;

[0024] Figure 7 This is a three-dimensional structural diagram of the card block and the grab bucket body in the separated state of this utility model;

[0025] Figure 8 In this utility model Figure 7 Enlarged schematic diagram of the structure at point B in the diagram;

[0026] Figure 9 This is a three-dimensional structural diagram of the card block insertion operation space in this utility model.

[0027] Figure 10 This is a front view schematic diagram of the adjusting gear structure in this utility model;

[0028] Figure 11 This is a three-dimensional structural diagram of the limiting block in this utility model;

[0029] Figure 12 In this utility model Figure 11 A magnified schematic diagram of the structure at point C.

[0030] In the diagram, 1. Column; 2. Grab body; 3. Hinge rod; 4. Hydraulic telescopic rod; 6. Fixing block; 7. Force rod; 8. Cylinder; 9. Output rod; 10. Oil inlet connector; 11. Locking rod; 12. Blade edge; 13. Hinge shaft; 14. Fixing shaft; 15. Adjusting gear; 16. Pressure spring; 17. Trapezoidal block; 18. Rotating shaft; 19. Rotation space; 20. Accommodation space; 21. Hinge space; 22. Operating space; 23. Toggle lever; 24. Limiting block; 25. Locking block; 26. Toggle lever clearance groove; 27. Limiting block clearance groove; 28. Fixing plate; 29. ​​Synchronizing gear. Detailed Implementation

[0031] Please see Figure 1-12 The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0032] The torque-adjustable fan-shaped shell grab of this utility model includes a column 1 and two grab bodies 2. Each grab body 2 has a hinge rod 3 fixedly installed on its upper end surface. The top end of each hinge rod 3 is rotatably connected to the column 1. Two hydraulic telescopic rods 4 are hinged to the outer surface of the column 1. The output end of each hydraulic telescopic rod 4 is hinged to a force rod 7. The bottom end of each force rod 7 is fixedly installed to the corresponding grab body 2. A force rod angle adjustment device is provided between the force rod 7 and the corresponding grab body 2. The force rod angle adjustment device is used to adjust the angle between the force rod 7 and the grab body 2.

[0033] In use, the top of the column 1 is connected to the lifting mechanism, which controls the raising and lowering of the column 1, thereby raising and lowering the two grab bucket bodies 2. The lifting mechanism is a conventional lifting mechanism found on cranes, typically consisting of a winch and a wire rope. The wire rope is released and wound up by rotating the winch. The free end of the wire rope is fixed to the top of the column 1, achieving the purpose of raising and lowering the column 1. When lowering the grab bucket bodies 2, the hydraulic telescopic rod 4 retracts, causing the two grab bucket bodies 2 to rotate synchronously. Each grab bucket body 2 rotates around the rotation axis 18 at the top of the hinge rod 3 via a hinge rod 3, keeping both grab bucket bodies 2 in the open state. Figure 2 With both grab bucket bodies 2 in a closed state, Figure 3 When the two grab bucket bodies 2 are in the open state and come into contact with the material pile, the hydraulic telescopic rod 4 is extended to drive the two grab bucket bodies 2 to rotate synchronously, causing the two grab bucket bodies 2 to close. During the closing process, the cutting edges 12 of the two grab bucket bodies 2 penetrate into the material pile to grab the material. After the two grab bucket bodies 2 are fully closed, the lifting mechanism controls the column 1 to rise, thereby driving the two closed grab bucket bodies 2 to rise, achieving the purpose of lifting the material. Then, the grab bucket bodies 2 are moved to the designated location and opened to release the material.

[0034] The cutting edge 12 of the grab bucket body 2 requires different torques to enter different material piles. When it is necessary to adjust the torque of the grab bucket body 2, firstly, the hinge shaft 13 connecting the hydraulic telescopic rod 4 and the lever 7 is pulled out, so that the output end of the hydraulic telescopic rod 4 is disengaged from the lever 7; then, the angle of the lever 7 relative to the grab bucket body 2 is adjusted by the lever angle adjustment device; Figure 2 and Figure 3For example, when lever 7 rotates around its inner end, causing the outer ends of the two levers 7 to move away from each other, the linear distance between the outer end of lever 7 and the top of hinge rod 3 increases. This increases the torque of the hydraulic telescopic rod 4 controlling the grab body 2, and then the output rod 9 of the hydraulic telescopic rod 4 is hinged to lever 7. On the other hand, the output rod 9 of the hydraulic telescopic rod 4 needs to extend further than before to achieve the closed state of the two grab bodies 2, and it needs to retract shorter than before to achieve the original open state of the two grab bodies 2. Therefore, the stroke of the hydraulic telescopic rod 4 needs to be adjusted to achieve the closed and open states of the grab bodies 2. The adjustment method for the stroke of the hydraulic telescopic rod 4 is as follows:

[0035] The existing hydraulic telescopic rod 4 includes a cylinder body 8 and an output rod 9. A piston is fixedly installed at the top of the output rod 9. The piston is slidably installed inside the cylinder body 8. The space inside the cylinder body 8 above the piston is the upper chamber, and the space inside the cylinder body 8 below the piston is the lower chamber. Two oil inlet connectors 10 are fixedly installed on the cylinder body 8, and the two oil inlet connectors 10 are connected to the upper chamber and the lower chamber respectively. The hydraulic telescopic rod 4 is generally controlled by controlling the opening and closing of the oil valve at the oil inlet connector 10. The stroke of the output rod 9 of the hydraulic telescopic rod 4 can be adjusted by controlling the opening and closing time of the oil valve at the oil inlet connector 10.

[0036] The adjustment for a smaller torque is the same as described above. Similarly, when the torque requirement for the grab body 2 is not strict, the opening and closing degree of the two grab bodies 2 can be adjusted in this way to achieve the purpose of adjusting the amount of material grabbed in a single operation. When the opening and closing degree of the two grab bodies 2 increases, the amount of material grabbed in a single operation increases; when the opening and closing degree of the two grab bodies 2 decreases, the amount of material grabbed in a single operation decreases.

[0037] When grabbing some bulk materials with high density, such as crushed ore, the weight of the material grabbed by the grab bucket body 2 each time increases, which may exceed the rated load of the crane. Long-term overload operation will affect the life of the crane. The opening degree of the two grab bucket bodies 2 can be adjusted to be smaller, so that the amount of material grabbed at one time is reduced, and the weight of the grabbing amount is within the rated load.

[0038] In this embodiment, a fixing block 6 is fixedly installed at the bottom end of the column 1. Two hinge rods 3 are fixed on each grab bucket body 2 and are arranged in the front-rear direction on the upper end face of the grab bucket body 2. The top end of the front hinge rod 3 is hinged to the front side of the fixing block 6, and the top end of the rear hinge rod 3 is hinged to the rear side of the fixing block 6. In use, the hydraulic telescopic rod 4 extends and retracts, causing the corresponding grab bucket body 2 to rotate. The rotation of the grab bucket body 2 causes the two corresponding hinge rods 3 to rotate simultaneously, thus achieving the purpose of rotating the grab bucket body 2. The two hinge rods 3 on each grab bucket body 2 increase the stability of the rotation of the grab bucket body 2.

[0039] In this embodiment, the lever angle adjustment device includes a fixed shaft 14 fixedly mounted on the top of the lever 7, which is rotatably connected to the grab body 2. It also includes an adjusting gear 15 coaxially fixed on the fixed shaft 14. Two locking rods 11 are hinged above the adjusting gear 15 on the grab body 2. The two locking rods 11 are symmetrically arranged with respect to the adjusting gear 15. A pressure spring 16 is fixedly mounted on the outer side of each locking rod 11. The outer ends of the pressure springs 16 are fixedly mounted to the grab body 2. The pressure springs 16 constantly push the outer ends of the locking rods 11 to move closer together, so that the outer ends of each locking rod 11 are engaged in the adjusting gear 15, preventing the adjusting gear 15 from rotating in any direction. An unlocking device is provided between the two locking rods 11. The unlocking device is used to push the outer end of either locking rod 11 away from the adjusting gear 15. When the unlocking device is in its initial position, the outer ends of both locking rods 11 are engaged between the teeth of the adjusting gear 15, preventing the adjusting gear 15 from rotating in any direction.

[0040] During normal use, the unlocking device is in its initial position, with the outer ends of both locking rods 11 positioned between the teeth of the adjusting gear 15, preventing the adjusting gear 15 from rotating in any direction. This effectively makes the lever 7 and the grab body 2 a single, fixed unit. When it is necessary to adjust the angle between the lever 7 and the grab body 2, the unlocking device pushes the outer end of the corresponding locking rod 11 away from the adjusting gear 15. Then, the lever 7 is rotated. When the angle of the lever 7 reaches the set position, the unlocking device returns to its initial position. The locking rod 11, whose outer end is disengaged from the adjusting gear 15, rotates under the pressure of the corresponding pressure spring 16 until its outer end engages with the teeth of the adjusting gear 15. Figure 10 For example, when the unlocking device pushes the left locking rod 11 to rotate outward and disengages its outer end from the teeth of the adjusting gear 15, the adjusting gear 15 can rotate clockwise, that is, the lever 7 can rotate clockwise; when the unlocking device pushes the right locking rod 11 to rotate outward and disengages its outer end from the teeth of the adjusting gear 15, the adjusting gear 15 can rotate counterclockwise, that is, the lever 7 can rotate counterclockwise; the angle of the lever 7 can be adjusted as needed.

[0041] In this embodiment, the unlocking device includes a trapezoidal block 17. When the unlocking device is in the initial position, the upper and lower sides of the trapezoidal block 17 are perpendicular to the line of symmetry between the two locking rods 11, and the inner side of each locking rod 11 is in contact with the corresponding side of the trapezoidal block 17. At this time, the outer ends of the two locking rods 11 are located between the teeth of the adjusting gear 15, thereby locking the adjusting gear 15 and preventing the adjusting gear 15 from rotating in any direction. This is equivalent to the force rod 7 being fixed to the grab body 2 through the fixed shaft 14 and the adjusting gear 15. A rotating shaft 18 is fixedly installed inside the trapezoidal block 17, and the rotating shaft 18 is rotatably connected to the grab body 2. When it is necessary to adjust the angle of the force rod 7, Figure 10 Using this as a reference, rotate the trapezoidal block 17 clockwise. The right side of the trapezoidal block 17 moves downward away from the right locking rod 11, while the left side of the trapezoidal block 17 moves upward, forcing the left locking rod 11 to rotate clockwise. This causes the outer end of the left locking rod 11 to disengage from the teeth of the adjusting gear 15. At this point, the adjusting gear 15 can rotate clockwise, which in turn allows the power rod 7 to rotate clockwise. If the power rod 7 needs to be adjusted counterclockwise, the same method applies.

[0042] In this embodiment, a rotation space 19 is provided on the grab body 2 at a position corresponding to the fixed shaft 14. The rotation space 19 is used to ensure that the adjustment lever 7 does not interfere with the rotation around the fixed shaft 14. An accommodating space 20 is provided on the inner side wall of the rotation space 19. The adjusting gear 15 is located in the accommodating space 20. A hinge space 21 communicating with the accommodating space 20 is provided on the inner side wall of the rotation space 19 located above the accommodating space 20. Both locking levers 11 are located in the hinge space 21. The outer ends of both pressure springs 16 are fixedly set to the grab body 2 through the inner side wall of the hinge space 21. The arrangement of the accommodating space 20 and the hinge space 21 makes the layout of the adjusting gear 15 and the locking lever 11 more compact and reasonable.

[0043] In this embodiment, the grab body 2 has an operating space 22. The rotation axis 18 of the trapezoidal block 17 extends rearward into the operating space 22 and is fixedly provided with a lever 23. When the lever 23 is rotated, the lever 23 drives the trapezoidal block 17 to rotate through the rotation axis 18. When the lever 23 is in a vertical state, the trapezoidal block 17 is in the initial position. The rotation of the lever 23 drives the trapezoidal block 17 to rotate, so that the trapezoidal block 17 pushes the outer end of the left locking lever 11 or the right locking lever 11 to disengage from the adjusting gear 15.

[0044] In this embodiment, limit blocks 24 are fixedly provided on both sides of the inner wall of the operating space 22 and the lever 23. When the lever 23 is rotated, the limit blocks 24 limit the lever 23.

[0045] In order to lock the vertical state of the lever 23, in this embodiment, a locking block 25 is engaged in the operating space 22. The side of the locking block 25 that is close to the lever 23 is provided with a lever clearance groove 26 and a limit block clearance groove 27. The lever 23 is located in the lever clearance groove 26, and the limit block 24 is located in the limit block clearance groove 27. The lever clearance groove 26 keeps the lever 23 in a vertical state. That is, during normal use, the trapezoidal block 17 is always in the initial position, the outer ends of the two locking rods 11 are engaged in the adjusting gear 15, the adjusting gear 15 cannot rotate, and the force rod 7 is fixed to the grab body 2.

[0046] In this embodiment, a fixing plate 28 is fixedly installed on the outer side of the locking block 25. The fixing plate 28 is fixedly installed to the grab body 2 by bolts. When it is necessary to adjust the angle of the lever 7, the bolts are removed, the fixing plate 28 and the locking block 25 are taken out from the operating space 22, and then the lever 23 can be rotated to adjust the angle of the lever 7.

[0047] In this embodiment, a synchronous gear 29 is fixedly provided at the top of each hinge rod 3, and the two synchronous gears 29 on the same side mesh with each other; the two synchronous gears 29 can ensure that the rotation of the two hinge rods 3 is synchronized when the two hydraulic telescopic rods 4 move inconsistently, thereby ensuring that the two grab bucket bodies 2 rotate synchronously.

[0048] The working principle of this utility model is as follows: When it is necessary to adjust the torque of the grab body 2, firstly, the hinge shaft 13 connecting the hydraulic telescopic rod 4 and the force rod 7 is pulled out, so that the output end of the hydraulic telescopic rod 4 is disengaged from the force rod 7; then, the fixing plate 28 and the locking block 25 are disassembled, and then the lever 23 is rotated, so that the lever 23 drives the trapezoidal block 17 to rotate and push open the corresponding locking rod 11, so that the outer end of the corresponding locking rod 11 is disengaged from the teeth of the adjusting gear 15. Then, the power rod 7 can be rotated. When the force rod 7 is rotated to the set position, the lever 23 is in a vertical state. At this time, try to rotate the power rod 7 in two directions to see if it can be rotated. If the force rod 7 cannot be rotated, it means that the outer ends of the two locking rods 11 are engaged between the teeth of the adjusting gear 15. Then, the locking block 25 is installed and the fixing plate 28 is fixed to the grab body 2 by bolts to complete the adjustment of the angle of the force rod 7.

Claims

1. A torque-adjustable fan-shaped shell grab, comprising a column (1) and two grab bodies (2), characterized in that: Each grab body (2) has a hinge rod (3) fixedly installed on its upper end face. The top of each hinge rod (3) is rotatably connected to the column (1). Two hydraulic telescopic rods (4) are hinged to the outer surface of the column (1). Each hydraulic telescopic rod (4) has a force rod (7) hinged to its output end. The bottom end of each force rod (7) is fixedly installed to the corresponding grab body (2). A force rod angle adjustment device is provided between the force rod (7) and the corresponding grab body (2). The force rod angle adjustment device is used to adjust the angle between the force rod (7) and the grab body (2).

2. The torque-adjustable fan-shaped shell grabber according to claim 1, characterized in that: The bottom end of the column (1) is fixedly provided with a fixing block (6). Each grab body (2) is fixed with two hinge rods (3), which are arranged in the front and back direction on the upper surface of the grab body (2). The top end of the front hinge rod (3) is hinged to the front side of the fixing block (6), and the top end of the rear hinge rod (3) is hinged to the rear side of the fixing block (6).

3. The torque-adjustable fan-shaped shell grabber according to claim 1, characterized in that: The lever angle adjustment device includes a fixed shaft (14) fixedly mounted on the top of the lever (7), the fixed shaft (14) being rotatably connected to the grab body (2), and an adjusting gear (15) coaxially fixedly mounted on the fixed shaft (14). Two locking rods (11) are hinged above the adjusting gear (15) on the grab body (2). The two locking rods (11) are symmetrically arranged on the left and right with the adjusting gear (15) as the reference. A pressure spring (16) is fixedly mounted on the outer side of each locking rod (11). The outer ends of the pressure springs (16) are fixedly set to the grab body (2). The pressure springs (16) always push the outer ends of the locking rods (11) to move closer to each other, so that the outer ends of each locking rod (11) are engaged in the adjusting gear (15). An unlocking device is provided between the two locking rods (11). The unlocking device is used to push the outer end of either locking rod (11) to disengage from the adjusting gear (15). When the unlocking device is in the initial position, the outer ends of both locking rods (11) are engaged between the teeth of the adjusting gear (15).

4. The torque-adjustable fan-shaped shell grabber according to claim 3, characterized in that: The unlocking device includes a trapezoidal block (17). When the unlocking device is in the initial position, the upper and lower sides of the trapezoidal block (17) are perpendicular to the line of symmetry between the two locking rods (11), and the inner side of each locking rod (11) is in contact with the corresponding side of the trapezoidal block (17). At this time, the outer ends of the two locking rods (11) are located between the teeth of the adjusting gear (15). A rotating shaft (18) is fixedly installed inside the trapezoidal block (17), and the rotating shaft (18) is rotatably connected to the grab body (2).

5. The torque-adjustable fan-shaped shell grabber according to claim 3, characterized in that: A rotating space (19) is provided on the grab body (2) at a position corresponding to the fixed shaft (14); an accommodating space (20) is provided on the inner side wall of the rotating space (19), and an adjusting gear (15) is located in the accommodating space (20). A hinge space (21) communicating with the accommodating space (20) is provided on the inner side wall of the rotating space (19) located above the accommodating space (20). Both locking rods (11) are located in the hinge space (21), and the outer ends of both pressure springs (16) are fixedly set to the grab body (2) through the inner side wall of the hinge space (21).

6. The torque-adjustable fan-shaped shell grab according to claim 4, characterized in that: The grab body (2) is provided with an operating space (22), and the rotation axis (18) of the trapezoidal block (17) extends backward into the operating space (22) and is fixedly provided with a lever (23).

7. The torque-adjustable fan-shaped shell grab according to claim 6, characterized in that: Limit blocks (24) are fixedly installed on both sides of the inner wall of the operating space (22) and the lever (23).

8. The torque-adjustable fan-shaped shell grabber according to claim 7, characterized in that: The operating space (22) is fitted with a locking block (25). The side of the locking block (25) that is close to the lever (23) is provided with a lever clearance groove (26) and a limit block clearance groove (27). The lever (23) is located in the lever clearance groove (26), and the limit block (24) is located in the limit block clearance groove (27). The lever clearance groove (26) keeps the lever (23) in a vertical position.

9. The torque-adjustable fan-shaped shell grabber according to claim 8, characterized in that: A fixing plate (28) is fixedly installed on the outer side of the card block (25), and the fixing plate (28) is fixedly installed to the grab body (2) by bolts.

10. The torque-adjustable sector-shaped shell grab according to claim 1, characterized in that: The top of each of the hinge rods (3) is fixedly provided with a synchronous gear (29), and the two synchronous gears (29) on the same side mesh with each other.

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