CN106744263B - Hook mechanism and its working state conversion method and tower crane - Google Patents

Abstract

The invention discloses a hook mechanism, a method for converting the working state of the hook mechanism and a tower crane, wherein the hook mechanism comprises: an arm tip (1); a main hook (6) having a first pulley (601), a second pulley (602), and a hook (603); a pulley yoke (3) comprising a third pulley (301); a secondary hook (5) comprising a fourth pulley (501); a traction rope (2); wherein the secondary hook (5) is selectively detachably connectable to the main hook (6) or the sheave frame (3), the traction rope (2) is passed around the first pulley (601), the fourth pulley (501) and the second pulley (602) in sequence, and the second end of the traction rope (2) is selectively connectable to the sheave frame (3) or the secondary hook (5). The working state of the lifting hook mechanism is changed without disassembling the auxiliary lifting hook, so that the operation of disassembling or installing the traction rope for the auxiliary lifting hook is omitted, and the working efficiency is improved.

Description

Hook mechanism and its working state conversion method and tower crane

technical field

The invention relates to engineering machinery, in particular to a hook mechanism, a method for converting its working state, and a tower crane.

Background technique

Tower crane, short for "tower crane", is a kind of lifting equipment used in building construction.

The tower crane lifts heavy objects through the cooperation of multiple pulleys and hooks. According to the number of pulleys and the winding method of the traction rope, the lifting ratio is also different. When lifting heavy objects, the magnification here is the multiple relationship between the total length of the traction rope retracted and the height of the heavy object, and the higher the magnification, the smaller the load on the traction rope. When the lifting weight is small, it can be hoisted in a low-magnification working state, and when the lifting weight is large, it can be hoisted in a high-magnification working state.

The hook mechanism of the tower crane can switch between working states of different magnifications. The structure of the currently used hook mechanism changes relatively greatly when switching between different working states. It is often necessary to add or remove some auxiliary parts on the hook mechanism. The operation amount and operation time are reduced, and in some working conditions, some parts of the traction rope extend at an oblique angle, and there is a horizontal component force, which causes the hook mechanism to easily produce horizontal displacement and the working condition is unstable.

Contents of the invention

The object of the present invention is to provide a hook mechanism with higher conversion efficiency of lifting ratio.

In order to achieve the above object, the present invention provides a hook mechanism, wherein, the hook mechanism includes: arm tip section, the arm tip section is equipped with a traction device; main hook, the main hook has a first pulley, a second Two pulleys and suspension hook; Pulley frame, this pulley frame includes the 3rd pulley, and this pulley frame is fixed on described arm point joint; Secondary suspension hook, described secondary suspension hook comprises the 4th pulley; Traction rope, this traction rope The first end is towed by the traction device, and the second end is provided with a connecting portion; wherein, the auxiliary hook can be selectively and detachably connected to the main hook or the pulley frame, and the traction rope passing around the first pulley, the fourth pulley and the second pulley in turn, and the second end of the traction rope can be selectively connected to the pulley frame or the auxiliary crane through the connecting portion hook.

Preferably, the hook mechanism can selectively work in a first state, a second state and a third state. In the first state, the auxiliary hook is connected to the pulley frame, and the traction rope is sequentially The first pulley, the fourth pulley and the second pulley are bypassed, and the connecting part is connected to the pulley frame; in the second state, the auxiliary hook is connected to the main pulley the hook, the traction rope goes around the first pulley, the fourth pulley, the second pulley and the third pulley in turn, and the connecting part is connected to the auxiliary hook; In the third state, the auxiliary hook is connected to the main hook, the traction rope goes around the first pulley, the fourth pulley and the second pulley in turn, and the connecting part is connected to The pulley frame.

Preferably, the first pulley, the second pulley and the fourth pulley have the same diameter, the diameter of the third pulley is 1.3-1.6 times the diameter of the first pulley, and the first pulley and the fourth pulley are The second pulley is arranged at the same height, and the rotation axis of the fourth pulley is aligned with the midpoint of the line connecting the rotation axes of the first pulley and the second pulley.

Preferably, the traction device is installed on the first end of the arm tip along the horizontal direction, the pulley frame is installed on the second end of the arm tip along the horizontal direction, and the pulley frame is formed with Two connection points of the two vertical tangents of the third pulley, one of which can be connected to the auxiliary hook and vertically aligned with the rotation axis of the fourth pulley, and the other connection point The point can be connected to the connection part of the traction rope, and the horizontal distance between the rotation axis of the third pulley and the traction device is 2-2.4 times the diameter of the first pulley.

Preferably, the arm tip section is provided with an auxiliary hanging point, the main hook is provided with an auxiliary hanging hole, and the hook mechanism further includes a sling, and the sling can pass through the auxiliary hanging hole Hang the main hook on the auxiliary hanging point.

Preferably, the connecting portion includes a tow rope anti-twist device.

Preferably, the lower end of the auxiliary hook is formed with a positioning groove and the upper end of the main hook is formed with a positioning protrusion, or the lower end of the auxiliary hook is formed with a positioning protrusion and the upper end of the main hook is A positioning groove is formed, and the auxiliary hook can be installed on the main hook in a state where the positioning protrusion is inserted into the positioning groove.

Preferably, the pulley frame includes two splints stacked and spaced from each other, the third pulley is clamped between the two splints, and the two splints are detachably threaded with a rope retaining pin, so The rope-stopping pin shaft is arranged around the third pulley, and the vertical height of the rope-stopping pin shaft is not lower than the rotation axis of the third pulley.

Preferably, the traction device includes a fixed pulley or a hoisting device.

In addition, the present invention also provides a method for converting the working state of the hook mechanism, wherein the hook mechanism is the hook mechanism described in the above solution, and the conversion method includes that the hook mechanism is replaced by the first A method for transitioning from one state to the second state: lifting the main hook to a height close to the pulley frame; connecting the auxiliary hook to the main hook, and releasing the auxiliary hook and the connection between the pulley frame; release the connection between the connecting part and the pulley frame, pass the second end of the traction rope around the third pulley, and connect the connecting part to the Deputy hook.

Preferably, the switching method further includes the method of switching the hook mechanism from the second state to the third state: lifting the main hook to a height close to the pulley frame; releasing the The connection between the connection part and the auxiliary hook releases the traction rope wound around the third pulley, and connects the connection part to the pulley frame.

Preferably, the switching method further includes the method of switching the hook mechanism from the first state to the third state: lifting the main hook to a height close to the pulley frame; The auxiliary hook is connected to the main hook, and the connection between the auxiliary hook and the pulley frame is released.

Preferably, after the main hook is lifted to a height close to the pulley frame, the main hook is hung on the jib tip section using a lifting rope.

In addition, the present invention also provides a tower crane, wherein the tower crane is equipped with the hook mechanism described in the above solution.

Through the above technical solution, under different working conditions, the auxiliary hook is always kept in the hook mechanism without disassembly, which saves the operation of disassembling or installing the traction rope on the auxiliary hook, and improves the work efficiency.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a structural schematic diagram of a hook mechanism in a first state according to an embodiment of the present invention;

Fig. 2 is a structural schematic diagram of the hook mechanism in a second state according to an embodiment of the present invention;

Fig. 3 is a structural schematic diagram of the hook mechanism in a third state according to an embodiment of the present invention;

Fig. 4 is a schematic structural view of a pulley frame of a hook mechanism according to an embodiment of the present invention.

Explanation of reference signs

1 Arm tip 2 Pull rope

3 Pulley bracket 4 Connecting part

5 secondary hooks 6 main hooks

7 traction device

301 Third pulley 302 Rope retaining pin

303 splint

501 Fourth Pulley

601 First pulley 602 Second pulley

603 Hook

detailed description

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

In the present invention, unless otherwise specified, the used orientation words such as "up and down" usually refer to the orientation of the hook mechanism when it is normally hung and used in the vertical direction.

The present invention provides a hook mechanism, wherein the hook mechanism includes: arm tip 1, the arm tip 1 is equipped with a traction device 7; a main hook 6, the main hook 6 has a first pulley 601, Second pulley 602 and suspension hook 603; Pulley frame 3, this pulley frame 3 comprises the 3rd pulley 301, and this pulley frame 3 is fixed on described arm tip section 1; Secondary suspension hook 5, described secondary suspension hook 5 comprises the first Four pulleys 501; traction rope 2, the first end of the traction rope 2 is pulled by the traction device 7, and the second end is provided with a connecting part 4; wherein, the auxiliary hook 5 can be selectively and detachably connected For the main hook 6 or the pulley frame 3, the traction rope 2 goes around the first pulley 601, the fourth pulley 501 and the second pulley 602 in turn, and the traction rope 2 The second end can be selectively connected to the pulley frame 3 or the auxiliary hook 5 through the connecting portion 4 .

In the hook mechanism described above, the auxiliary hook 5 plays an important role in the transition of the hook mechanism between different working states. When the traction rope 2 bypasses the first pulley 601, the fourth In the case of the pulley 501 and the second pulley 602, when the auxiliary hook 5 is connected to the main hook 6, the main hook 6 and the auxiliary hook 5 become a single whole, which can be regarded as a single fixed pulley. When the hook 5 is connected to the pulley frame 3 , the first pulley 601 , the fourth pulley 501 and the second pulley 602 are independent, so that the hook mechanism can be converted to a higher-magnification working state. In addition, the second end of the traction rope 2 is connected to different positions, and in combination with the connection method of the auxiliary hook 5, various working states, that is, different lifting methods with different magnifications, can be realized. When the hook mechanism switches between different working states, the auxiliary hook 5 is always kept in the winding state, and it is not necessary to disassemble the auxiliary hook 5, which reduces the workload and improves the work efficiency.

Specifically, the hook mechanism can selectively work in the first state, the second state and the third state,

In the first state, as shown in FIG. 1 , the auxiliary hook 5 is connected to the pulley frame 3, and the traction rope 2 goes around the first pulley 601, the fourth pulley 501 and The second pulley 602, and the connecting part 4 is connected to the pulley frame 3;

In the second state, as shown in FIG. 2 , the auxiliary hook 5 is connected to the main hook 6, and the traction rope 2 passes around the first pulley 601 and the fourth pulley 501 in turn. , the second pulley 602 and the third pulley 301, and the connecting portion 4 of the traction rope 2 is connected to the auxiliary hook 5;

In the third state, as shown in FIG. 3 , the auxiliary hook 5 is connected to the main hook 6, and the traction rope 2 passes around the first pulley 601 and the fourth pulley 501 in turn. and the second pulley 602 , and the connecting portion 4 of the traction rope 2 is connected to the pulley frame 3 .

The first state is the working state of quadruple rate, the second state is the working state of triple rate, and the third state is the working state of double rate. The device 7 needs to pack up (or release) four unit lengths, three unit lengths, and two unit lengths of the traction rope 2 respectively. The working state with a higher magnification can be used for the situation that the lifting weight is larger or the lifting distance is smaller. The working state of low magnification can be used in the case of small lifting weight or large lifting distance.

Further, the diameter of the first pulley 601, the second pulley 602 and the fourth pulley 501 are the same, the diameter of the third pulley 301 is 1.3-1.6 times the diameter of the first pulley 601, the The first pulley 601 and the second pulley 602 are arranged at the same height, and the rotation axis of the fourth pulley 501 is aligned with the midpoint of the line connecting the rotation axes of the first pulley 601 and the second pulley 602 . Further preferably, the diameter of the third pulley 301 is 1.5 times the diameter of the first pulley 601 . In this structure, as shown in Figure 1, the two sections of traction rope 2 wound between the first pulley 601, the second pulley 602 and the fourth pulley 501 are kept parallel and extend vertically, and, as shown in Figure 2, the first The 1.5 times the diameter of the three pulleys 301 can also allow the two sections of traction rope 2 wound around the third pulley 301 to maintain parallel and vertical extension. Certainly, the diameter of the third pulley 301 can be kept as 1.3-1.6 times of the diameter of the first pulley 601. At this time, there is a small angle between the two sections of traction rope 2 wound around the third pulley 301 and the vertical direction, which can basically be ignored. . In the case that the multi-section traction rope 2 keeps extending vertically, the traction rope 2 has no horizontal force component, which avoids causing horizontal traction to each component and improves the stability of the overall structure.

Further, the traction device 7 is installed on the first end of the arm tip 1 along the horizontal direction, the pulley frame 3 is installed on the second end of the arm tip 1 along the horizontal direction, and the pulley frame 3 There are two connection points respectively aligned with the two vertical tangents of the third pulley 301, wherein one of the connection points can be connected to the auxiliary hook 5 and vertically aligned with the fourth pulley 501. The other connecting point can be connected to the connecting part 4 of the traction rope 2, and the horizontal distance between the rotating axis of the third pulley 301 and the traction device 7 is the diameter of the first pulley 601 2-2.4 times (preferably 2.25 times) of that. As shown in Figure 1, the two connection points of the pulley frame 3 are respectively formed at the lower end, and the two connection points respectively pass through the two tangent lines along the vertical direction of the third pulley 301, and the connection points between the auxiliary hook 5 and the pulley frame 3 Correspondingly, the axis of rotation of the fourth pulley 501 is vertically aligned, thereby ensuring that the hook mechanism is in the first state, the second state and the third state, and the traction rope 2 is all vertically extended in any section between the pulleys, so as to avoid Traction rope 2 produces horizontal traction.

In addition, the arm tip section 1 is provided with an auxiliary hanging point, the main hook 6 is provided with an auxiliary hanging hole, and the hook mechanism also includes a sling, and the sling can pass through the auxiliary hanging The hole hangs the main hook 6 on the auxiliary hanging point. At least two horizontally spaced auxiliary hanging points can be set on the jib tip section 1, correspondingly, two horizontally spaced auxiliary hanging holes can be set on the main hook 6, so that the main hook can be hung smoothly by two lifting ropes 6. When the hook mechanism switches its working state, the main hook 6 is hung by the sling rope, and the staff can complete the switching operation only at the tip section 1 of the arm.

In addition, the connecting part 4 includes a pull rope anti-twist device. The traction rope anti-twist device mainly prevents the traction rope 2 from rotating and knotting, so as to ensure that the traction rope 2 can be smoothly wound around the pulley and followed by the rolling traction of the pulley. The connecting part 4 may include a hook-shaped piece, so as to hang on the corresponding position of the pulley frame 3 or the auxiliary hook 5 through the hook-shaped piece.

In addition, the lower end of the auxiliary hook 5 is formed with a positioning groove and the upper end of the main hook 6 is formed with a positioning protrusion, or the lower end of the auxiliary hook 5 is formed with a positioning protrusion and the main hanger 6 is formed with a positioning protrusion. A positioning groove is formed on the upper end of the hook 6 , and the auxiliary hook 5 can be installed on the main hook 6 when the positioning protrusion is inserted into the positioning groove. The positioning projection and the positioning groove can ensure that the auxiliary hook 5 and the main hook 6 are installed in a standard relative position, in particular, the rotation axis of the fourth pulley 501 is aligned with the first pulley 601 and the second pulley 602 Connect midpoint. The auxiliary hook 5 and the main hook 6 can be formed with connecting lugs respectively, and the connecting lugs of the two can be passed through the pin shaft to realize the connection. The connection between the auxiliary hook 5 and the pulley frame 3 can also be connected in this way.

In addition, the pulley frame 3 includes two splints 303 spaced apart from each other, the third pulley 301 is clamped between the two splints 303, and the two splints 303 are detachably threaded with a rope retaining pin 302 , the rope-stopping pin shaft 302 is arranged around the third pulley 301 , and the vertical height of the rope-stopping pin shaft 302 is not lower than the rotation axis of the third pulley 301 . As shown in FIG. 4 , the splints 303 are connected by plates, and the two ends of the rotating shaft of the third pulley 301 are installed on the two splints 303 respectively. The rope retaining pin 302 is located around the upper half of the circumference of the third pulley 301 (that is, the part around the traction rope 2), and the rope retaining pin 302 keeps a small distance from the periphery of the third pulley 301 to prevent the traction rope 2 Accidentally slip out, especially, when pulling out the pulling rope 2 from the third pulley 301, you can take off the rope retaining pin 302, so that the second end of the pulling rope 2 (the volume of the connecting part 4 is relatively large) is more To draw it out smoothly.

In addition, the main hook 6 and the auxiliary hook 5 can also adopt a structure similar to the pulley frame 3, that is, the pulley is clamped and installed by two splints, and the lower end of the main hook 6 can be installed with a hook 603 .

Specifically, the traction device 7 includes a fixed pulley or a hoisting device. A fixed pulley can be installed on the arm tip 1, and the first end of the traction rope 2 is wound around the fixed pulley for traction, or a hoisting device can be installed on the arm tip 1, and the traction rope 2 is taken up or released by the hoisting device.

In addition, the present invention provides a method for switching the working state of the hook mechanism, the switching method comprising:

a. The method for converting the hook mechanism from the first state to the second state: lift the main hook 6 to a height close to the pulley frame 3; connect the auxiliary hook to the The main hook 6, and release the connection between the auxiliary hook 5 and the pulley frame 3; release the connection between the connecting part 4 and the pulley frame 3, and the second part of the traction rope 2 ends around the third pulley 301, and connects the connecting part 4 to the auxiliary hook 5;

b. The method for the hook mechanism to switch from the second state to the third state: lift the main hook 6 to a height close to the pulley frame 3; release the connecting part 4 from the third state; The connection of the auxiliary hook 5 is released, the traction rope 2 wound on the third pulley 301 is released, and the connecting part 4 is connected to the pulley frame 3;

c. The method for converting the hook mechanism from the first state to the third state: lift the main hook 6 to a height close to the pulley frame 3; connect the auxiliary hook to the The main hook 6 is released, and the connection between the auxiliary hook 5 and the pulley frame 3 is released.

In addition, when the hook mechanism is converted from the third state to the first state or the second state and from the second state to the first state, the main hook 6 is lifted to the same position as the pulley frame 3 After approaching the height, use the reverse operation and reverse operation of the corresponding method above.

In addition, after the main hook 6 is lifted to a height close to the pulley frame 3 , the main hook 6 is hung on the jib tip section 1 by using a lifting rope. As mentioned above, the jib tip section 1 is provided with an auxiliary hanging point, and the main hook 6 is provided with an auxiliary hanging hole, so that the main hook can be hoisted by the sling during the transition of the working state of the hook mechanism. 6. The staff can complete relevant operations only at the tip of the arm 1, and the lifting rope can be removed after the conversion work is completed. And, in the transition of the three working states, the auxiliary hook 5 is connected to the main hook 6 or the pulley frame 3, especially, the traction rope 2 is wound all the time, therefore, it is unnecessary to remove and install the traction rope on the auxiliary hook 5. The operation improves the efficiency of the working state transition of the hook mechanism.

In addition, the present invention also provides a tower crane, wherein the tower crane is equipped with the hook mechanism described in the above solution, so as to achieve lifting through the hook mechanism.

The preferred embodiment of the present invention has been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the specific details of the above embodiment, within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, These simple modifications all belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction. In order to avoid unnecessary repetition, various possible combinations are not further described in the present invention.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (14)

1. A suspension hook mechanism, characterized in that the suspension hook mechanism comprises: Arm tip (1), the arm tip (1) is equipped with a traction device (7); The main hook (6), the main hook (6) has a first pulley (601), a second pulley (602) and a hook (603); a pulley frame (3), the pulley frame (3) includes a third pulley (301), and the pulley frame (3) is fixed to the arm tip (1); An auxiliary hook (5), the auxiliary hook (5) including a fourth pulley (501); a traction rope (2), the first end of the traction rope (2) is drawn by the traction device (7), and the second end is provided with a connecting part (4); Wherein, the auxiliary hook (5) can be selectively and detachably connected to the main hook (6) or the pulley frame (3), and the traction rope (2) goes around the first pulley (601), the fourth pulley (501) and the second pulley (602), and the second end of the traction rope (2) can be selectively connected to the The pulley frame (3) or the auxiliary hook (5). 2. The hook mechanism according to claim 1, characterized in that the hook mechanism can selectively work in the first state, the second state and the third state, In the first state, the auxiliary hook (5) is connected to the pulley frame (3), and the traction rope (2) goes around the first pulley (601) and the fourth pulley in sequence (501) and the second pulley (602), and the connecting part (4) is connected to the pulley frame (3); In the second state, the auxiliary hook (5) is connected to the main hook (6), and the traction rope (2) turns around the first pulley (601), the fourth a pulley (501), the second pulley (602) and the third pulley (301), and the connecting part (4) is connected to the auxiliary hook (5); In the third state, the auxiliary hook (5) is connected to the main hook (6), and the traction rope (2) turns around the first pulley (601), the fourth The pulley (501) and the second pulley (602), and the connecting part (4) is connected to the pulley frame (3). 3. The hook mechanism according to claim 2, characterized in that, the first pulley (601), the second pulley (602) and the fourth pulley (501) have the same diameter, and the third The diameter of the pulley (301) is 1.3-1.6 times of the diameter of the first pulley (601), the first pulley (601) and the second pulley (602) are set at the same height, and the fourth pulley (501 ) is aligned with the midpoint of the line connecting the axes of rotation of the first pulley (601) and the second pulley (602). 4. The hook mechanism according to claim 3, characterized in that, the traction device (7) is installed at the first end of the arm tip (1) along the horizontal direction, and the pulley frame (3) is installed At the second end of the arm tip (1) along the horizontal direction, the pulley frame (3) is formed with two connection points respectively aligned with the two vertical tangents of the third pulley (301), wherein One of the connection points can be connected to the auxiliary hook (5) and vertically aligned with the rotation axis of the fourth pulley (501), and the other connection point can be connected to the pulley (2) The connecting portion (4), the horizontal distance between the rotation axis of the third pulley (301) and the traction device (7) is 2-2.4 times the diameter of the first pulley (601). 5. The hook mechanism according to claim 1, characterized in that, the arm tip (1) is provided with an auxiliary hanging point, the main hook (6) is provided with an auxiliary hanging hole, and the hanging The hook mechanism further includes a sling, and the sling can pass through the auxiliary hanging hole to hang the main hook (6) on the auxiliary hanging point. 6. The hook mechanism according to claim 1, characterized in that, the connecting part (4) comprises a tow rope anti-twist device. 7. The hook mechanism according to claim 1, characterized in that, the lower end of the auxiliary hook (5) is formed with a positioning groove and the upper end of the main hook (6) is formed with a positioning projection, or The lower end of the auxiliary hook (5) is formed with a positioning lug and the upper end of the main hook (6) is formed with a positioning groove. In the state where the positioning lug is inserted into the positioning groove, the The auxiliary hook (5) can be attached to the main hook (6). 8. The hook mechanism according to claim 1, characterized in that, the pulley frame (3) comprises two splints (303) stacked and spaced from each other, and the third pulley (301) is clamped between the two splints (303). Between the splints (303), the two splints (303) are detachably threaded with a rope-stop pin (302), and the rope-stop pin (302) is arranged around the third pulley (301) , and the vertical height of the rope retaining pin (302) is not lower than the rotation axis of the third pulley (301). 9. The hook mechanism according to claim 1, characterized in that the traction device (7) comprises a fixed pulley or a hoisting device. 10. A method for converting the working state of a hook mechanism, characterized in that, the hook mechanism is the hook mechanism according to claim 2, and the conversion method comprises changing the hook mechanism from the first state to A method of transitioning to said second state: Lift the main hook (6) to a height close to the pulley frame (3); connecting the auxiliary hook to the main hook (6), and releasing the connection between the auxiliary hook and the pulley frame (3); Release the connection between the connecting part (4) and the pulley frame (3), bypass the second end of the traction rope (2) around the third pulley (301), and put the connecting part (4) ) is connected to the auxiliary hook (5). 11. The conversion method according to claim 10, characterized in that, the conversion method further comprises a method of converting the hook mechanism from the second state to the third state: Lift the main hook (6) to a height close to the pulley frame (3); release the connection between the connecting part (4) and the auxiliary hook (5), release the traction rope (2) wound on the third pulley (301), and connect the connecting part (4) to the Describe the pulley frame (3). 12. The conversion method according to claim 10, characterized in that, the conversion method further comprises a method of converting the hook mechanism from the first state to the third state: Lift the main hook (6) to a height close to the pulley frame (3); The auxiliary hook (5) is connected to the main hook (6), and the connection between the auxiliary hook and the pulley frame (3) is released. 13. The conversion method according to claim 11, characterized in that, after lifting the main hook (6) to a height close to the pulley frame (3), use a lifting rope to lift the main hook (6) 6) Hanging on the tip of the arm (1). 14. A tower crane, characterized in that the tower crane is equipped with the hook mechanism according to any one of claims 1-9.