CN117486061A - Unhook lifting appliance for lifting steel-structured cross beam - Google Patents

Abstract

A unhook hoist for crossbeam hoist and mount, includes plate body, lifting rope, carousel, torsional spring, reel, stay cord and synchronous rotary mechanism. The rotary table is provided with a pawl, a driving belt pulley and two rope passing holes, and the two rope passing holes are symmetrically arranged about the center of the rotary table; the winding disc is provided with a rope winding disc and a ratchet wheel which is matched with the pawl; the middle part of the pull rope is wound on the winding disc, and a hook is fixed at the end part of the pull rope; the synchronous rotating mechanism comprises a synchronous belt and a rotating hook, wherein a driven belt wheel and a hook plate are arranged on the rotating hook, and the driven belt wheel is connected with the driving belt wheel through the synchronous belt. The turntable, the winding disc and the pull rope form an automatic centering mechanism, the two hooks are respectively hooked at the two ends of the cross beam, so that the lifting appliance can automatically move to the central part of the cross beam, the center of gravity of the lifting appliance coincides with the center of gravity of the cross beam, and the unbalanced problem of the cross beam during lifting is solved. The hanger saves time and labor, automatically realizes hooking and unhooking of the cross beam, and eliminates unsafe factors in the existing hoisting mode.

Description

Unhook lifting appliance for lifting steel-structured cross beam

Technical Field

The invention relates to the field of steel structure buildings, in particular to a unhooking lifting appliance for lifting a steel structure beam.

Background

The frame of the steel structure building is formed by building upright posts and cross beams, the upright posts and the cross beams are usually H-shaped steel, and the H-shaped steel has the advantages of strong bending resistance, light structure weight, convenience in connection and the like. The upright posts are connected with the cross beam through bolts, and the cross beam needs to be horizontally hoisted when being installed.

Fig. 1 shows a hoisting schematic of a prior art cross beam. As can be seen from fig. 1, although the cross beam 100 is a long bar with a uniform cross section, it is difficult to hang the two suspension ropes 80 on the center of gravity of the cross beam 100, so that there is a deviation between the center of gravity of the suspension hook 90 and the center of gravity of the cross beam 100. Even small deviations can cause the cross beam to skew, large deviations can even cause the cross beam to drop. Therefore, when the crane is lifted, two constructors need to use ropes to pull at two ends of the cross beam so as to eliminate unbalance. Otherwise, the connecting holes at the two ends of the cross beam cannot be aligned with the connecting holes on the upright post, so that the mounting is difficult.

In addition, after the crossbeam is installed in place, the existing lifting appliance also has the problem that the lifting appliance can not be automatically unhooked. The constructor is required to ascend and take down the lifting rope from the lifting hook.

In conclusion, the existing beam lifting mode is labor-consuming and time-consuming and unsafe.

Disclosure of Invention

In order to overcome the defects in the background technology, the invention discloses a unhooking lifting appliance for lifting a cross beam, which aims at:

1. horizontal lifting is realized, and unbalance of the cross beam during lifting is eliminated;

2. automatic unhooking is realized, and unsafe factors are eliminated.

In order to achieve the aim of the invention, the invention adopts the following technical scheme:

a unhookable spreader for cross beam lifting, comprising:

the plate body is provided with a chute corresponding to the upper wing plate of the cross beam;

the lifting rope is connected with the plate body;

the rotating disc is arranged on the plate body and is provided with a pawl, a driving belt pulley and two rope passing holes, and the two rope passing holes are symmetrically arranged about the central line of the rotating disc;

the torsion spring is arranged between the turntable and the plate body and is used for applying torque to the turntable;

the winding disc is coaxially arranged on the turntable and is provided with a rope winding disc and a ratchet wheel; the ratchet wheel is matched with the pawl, and the unidirectional rotation direction of the ratchet wheel is the same as the direction of the torsion spring applying torque to the turntable;

the middle part of the pull rope is wound on the winding disc, and the rope outlet lengths of the two rope outlet parts are the same; the two rope outlet parts respectively penetrate through the two rope passing holes, and hooks are fixed at the end heads of the rope outlet parts;

the synchronous rotating mechanism comprises a synchronous belt and four rotating hooks; the rotary hook is arranged on the plate body, a driven belt pulley and a hook plate are arranged on the rotary hook, and the driven belt pulley is connected with the driving belt pulley through a synchronous belt;

when the two hooks are respectively hooked at the two ends of the cross beam, the four rotary hooks are driven to synchronously rotate through the pull ropes and the turntables, so that the hook plates are rotated to the hook positions; when the hook is taken down, under the action of the torsion spring, the four rotary hooks reversely rotate, so that the hook plate rotates to the unhooking position.

Further improved technical scheme, the carousel is installed in the central part of plate body, and four rotating hooks are rectangular array and are installed in the four corners of carousel.

Further improved technical scheme installs the take-up pulley on the plate body, and the take-up pulley is used for tensioning the hold-in range.

Further improve technical scheme, be fixed with the stopper on the plate body, the stopper is used for restricting the rotation angle of swivel hook.

According to the further improved technical scheme, the rope winding disc is provided with a radial through hole, the pull rope penetrates through the radial through hole, and the midpoint of the pull rope is fixed on the central line of the rope winding disc through the wire clamp.

Further improving the technical scheme, the center distance of two rope passing holes is larger than the diameter of the driving belt pulley, and the diameter of the driving belt pulley is larger than the diameter of the driven belt pulley.

According to the further improved technical scheme, a rod piece is fixed on the rotary table, the center of the rod piece is located on the center line of the rotary table, and two rope passing holes are formed in two ends of the rod piece.

A hoisting method of a beam comprises the following steps:

s1: the unhooking lifting appliance is arranged on the cross beam, and can slide along the cross beam through the cooperation of the sliding chute and the upper wing plate;

s2: two hooks are respectively hooked at two ends of the cross beam; if the pulling rope is not long enough, the pawl is disengaged from the ratchet wheel, and the pulling rope is released from the winding disc;

s3: setting the unidirectional rotation direction of the ratchet wheel as a clockwise direction; the winding disc is rotated clockwise to drive the four rotating hooks to synchronously rotate anticlockwise until reaching the hooking position; then, the cross beam is horizontally hoisted by a crane;

s4: after the cross beam is installed in place, loosening the lifting rope through the crane, and then taking down the two hooks; at this time, the four rotating hooks rotate clockwise to reach the unhooking position; finally, the unhooking lifting appliance is lifted off the cross beam through the crane.

After implementing the technical scheme, compared with the background technology, the unhooking crane has at least the following beneficial effects:

1. the turntable, the winding disc and the pull rope form an automatic centering mechanism, and the two hooks are respectively hooked at two ends of the cross beam, so that the lifting appliance can automatically move to the central part of the cross beam. Therefore, the center of the lifting hook coincides with the center of gravity of the cross beam, so that the problem that the cross beam is easy to skew during lifting is fundamentally solved, and conditions are created for alignment of the connecting holes.

2. In the centering process, the hanger also automatically realizes the hooking of the cross beam.

3. After the hook is taken down, the hanger can also realize automatic unhooking. Notably, when the cross beam is installed, constructors need to ascend, and the bolts are connected in the connecting holes between the cross beam and the upright posts. After the installation is completed, the constructor can take down the hook from the end part of the cross beam. Therefore, the unhooking operation of the lifting appliance does not need to occupy manpower and time additionally, and unsafe factors are eliminated.

4. The lifting appliance is also suitable for lifting cross beams with different lengths. When the cross beam is too long, the pull rope can be released from the winding disc by the release pawl; the crossbeam is too short, can wind the stay cord through the reel.

5. The winding disc has two functions besides the function of winding the pull rope, namely, the hook plate can be guaranteed to rotate in place; and secondly, the torque of the torsion spring is increased, and enough power is reserved for unhooking actions.

Drawings

Fig. 1 shows a hoisting schematic of a prior art cross beam.

Fig. 2 shows a schematic overall structure of the unhook crane.

Fig. 3 shows a schematic main structure of the unhook crane.

Fig. 4 shows an exploded view of fig. 3.

Fig. 5 shows a schematic view of the structure of the front side of the plate body.

Fig. 6 shows a schematic view of the structure of the back side of the board body.

Fig. 7 shows a schematic structural diagram of the turntable and the torsion spring.

Fig. 8 shows a schematic view of the structure of the take-up reel at one view angle.

Fig. 9 shows a schematic view of the reel in another view.

Fig. 10 shows a schematic structural view of a rotating hook.

Fig. 11 shows a schematic view of the hook plate in the unhooking position.

Fig. 12 shows a schematic view of the hook plate in the hooked position.

Fig. 13 shows a schematic view of the connection structure of the upright and the cross beam.

Fig. 14 shows a schematic structural diagram of the detachable sling before lifting.

Fig. 15 shows a schematic structural diagram of the detachable sling when the beam is hoisted.

Fig. 16 shows a schematic structural view of the detachable sling after unhooking.

In the figure:

10. a plate body; 11. a chute; 12. a limiting block; 13. rope passing plate; 14. lifting lugs; 15. a tensioning wheel; 16. a step hole;

20. a turntable; 21. a driving pulley; 22. a pawl; 23. a rod piece; 24. rope passing holes;

30. a reel; 31. a rope reel; 32. a ratchet wheel; 33. a hand wheel; 34. rope clips;

40. a torsion spring;

50. a pull rope; 51. a hook;

60. a rotating hook; 61. a driven pulley; 62. a hook plate;

70. a synchronous belt;

80. a hanging rope;

90. a lifting hook;

100. a cross beam; 101. an upper wing plate; 102. a web; 103. a lower wing plate; 104. a connection hole;

200. and (5) a column.

Detailed Description

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention. It should be noted that, in the description of the present invention, terms such as "front", "rear", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus are not to be construed as limiting the present invention. It should also be noted that, in the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; either directly or indirectly through intermediaries, or in communication with each other. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.

As shown in fig. 2 to 4, a unhooking hanger for beam lifting includes a plate body 10, a turntable 20, a torsion spring 40, a winding disc 30, a pulling rope 50, a lifting rope 80, and a synchronous rotation mechanism, the structure and function of which are described in detail below.

Refer to fig. 5. The plate body 10 is a strip-shaped steel plate, and two rope passing plates 13, four tensioning wheels 15 and four lifting lugs 14 for connecting lifting ropes 80 are arranged on the front surface of the plate body 10. A step hole 16 is arranged at the center of the plate body 10, and the lifting lug 14, the rope passing plate 13 and the tensioning wheel 15 are symmetrically arranged about the center of the step hole 16.

Refer to fig. 6. A chute 11 is provided on the back surface of the plate body 10, and the chute 11 is provided along the longitudinal direction of the plate body 10. The sliding groove 11 is matched with the upper wing plate 101 of the cross beam 100, so that the plate body 10 can slide along the cross beam 100. Four limiting blocks 12 are also fixed on the back of the plate body 10.

Refer to fig. 7. The main body of the turntable 20 is a revolution body, and a pawl 22, a driving pulley 21 and a lever 23 are provided on the turntable 20. Wherein the centre of the rod 23 coincides with the centre of the turntable 20. Two rope passing holes 24 are arranged at two ends of the rod piece 23, the two rope passing holes 24 are symmetrically arranged about the central line of the turntable 20, and the two rope passing holes 24 are equal to the center of the turntable 20. The function of the rod 23 is to increase the distance of the two rope holes 24 from the centre of the turntable 20 without increasing the diameter of the turntable body. The pawl 22 is mounted on the upper end surface of the turntable 20, and a turning spring is provided between the pawl 22 and the turntable 20. A torsion spring 40 is provided at the lower end surface of the turntable 20.

Reference is made to fig. 3-5. The turntable 20 is rotatably mounted within the stepped bore 16, and the torsion spring 40 is mounted between the turntable 20 and the stepped bore 16. One end of the torsion spring 40 is fixed to the turntable 20 and the other end is fixed to the stepped hole 16. The torsion spring 40 acts to apply a torque to the turntable 20. In this embodiment, the torsion spring 40 applies a torque to the turntable 20 in a clockwise direction.

Referring to fig. 8-9. The reel 30 is also a body of revolution, and the reel 30 is coaxially provided with a rope reel 31 and a ratchet 32. The middle part of the pull rope 50 is wound around the rope reel 31 so that the pull rope 50 has two rope-out portions. The function of the rope reel 31 is to pay-off and pay-back the rope 50 so that the payout lengths of the two payout portions are the same.

Specifically, a radial through hole is provided in the rope reel 31, the pull rope 50 penetrates through the radial through hole, and the midpoint of the pull rope 50 is fixed on the center line of the rope reel 31 by the rope clip 34. Thus, the winding drum 30 is rotated to wind and unwind the pull rope 50 with the same length, so that the lengths of the two rope outlet portions are ensured to be the same. The pull rope 50 can be made of thin steel wire rope or nylon rope with larger tensile strength. A hand wheel 33 is also provided on the take-up reel 30 for ease of rotation.

Reference is made to fig. 3-4. The reel 30 is coaxially sleeved on the turntable 20, and the ratchet 32 is matched with the pawl 22. The ratchet 32 and the pawl 22 can rotate the take-up reel 30 in one direction relative to the turntable 20 under the action of the torsion spring. Notably, the unidirectional rotation of the ratchet 32 is in the same direction as the torsion spring 40 applies torque to the dial 20. In this embodiment, the unidirectional rotation direction of the ratchet 32 is also clockwise.

Reference is made to fig. 2-4. Through holes are arranged on the rope passing plate 13, and the two rope outlet parts respectively pass through the two rope passing holes 24 on the rod piece 23 and then respectively pass through the through holes on the two rope passing plates 13. A hook 51 is fixed to the end of the rope portion. The rope passing plate 13 has the functions of firstly adjusting the rope outlet angle of the pull rope 50 and secondly clamping the hook 51 on the rope passing plate 13 after the pull rope 50 is wound up, so that the rope is convenient to store.

It should be noted that the rope passing hole 24 is not the only implementation form, and fixed pulleys may be disposed at two ends of the rod member 23, and the two rope outlet portions pass through the through holes of the two rope passing plates 13 after bypassing the two fixed pulleys respectively. The fixed pulley can reduce the resistance of the pull rope when being wound and unwound, but the pull rope 50 wound on the rope winding disc 31 can be scattered due to the reduction of the resistance, so that the unreliable factors are increased when the fixed pulley is used. Although the rope passing hole 24 increases the resistance of the rope when the rope is wound and unwound, the rope 50 on the rope reel 31 is in a tensioned state, and the rope scattering problem does not occur.

Reference is made to fig. 3-4. The synchronous rotation mechanism comprises a synchronous belt 70 and four rotating hooks 60, and the four rotating hooks 60 are arranged at four corners of the plate body 10 in a rectangular array. Four tensioning wheels 15 are arranged around the rotary table 20, and two tensioning wheels 15 are used for tensioning the synchronous belt 70, namely, increasing the wrap angle of the synchronous belt 70 on the driving pulley 21.

Reference is made to fig. 3, 4 and 10. The rotating hook 60 is provided with a driven pulley 61 and a hooking plate 62, and the hooking plate 62 is used for hooking the cross beam 100. The driven pulley 61 is connected with the driving pulley 21 through a synchronous belt 70, and when the turntable 20 rotates, the four rotating hooks 60 are driven to synchronously rotate in the same direction through the synchronous belt 70.

In the present embodiment, the diameter of the driving pulley 21 is twice the diameter of the driven pulley 61, the dial 20 is rotated by 90 °, and the rotating hook 60 is rotated by 180 °. The rotating hook 60 has two indexes, one is a hooking position of the hook plate 62 toward the chute 11, and the other is a unhooking position of the hook plate 62 away from the chute 11.

Refer to fig. 11. When the turntable 20 rotates to this position, the hook plate 62 is stopped at the unhooking position after touching the stopper 12.

Refer to fig. 12. When the turntable 20 rotates to this position, the hook plate 62 stops at the hook position after touching the stopper 12.

As can be seen from fig. 11-12, the distance between the hooks 51 is smaller when the hook plate 62 is in the unhooked position; when the hook plate 62 is in the hook position, the distance between the two hooks 51 is large. Therefore, during hoisting, the two hooks 51 are respectively hooked at the two ends of the cross beam 100, and the four rotating hooks 60 are driven to synchronously rotate by the pull rope 50 and the turntable 20, so that the hook plate 62 can be rotated from the unhooking position to the hooking position to hook the cross beam 100. When unhooking, the hook 51 is taken down, and the four rotating hooks 60 rotate reversely under the action of the torsion spring 40, so that the hook plate 62 can rotate from the hook position to the unhooking position, and the hook on the cross beam 100 is separated.

In order to further explain the lifting process of the lifting appliance, the invention also discloses a lifting method of the cross beam 100, which comprises the following steps:

s1: before hoisting, the unhooking hanger is placed on the cross beam 100, and the unhooking hanger can slide along the cross beam 100 through the cooperation of the chute 11 and the upper wing plate 101.

First, refer to fig. 13. In the field of steel structure construction, the columns 200 and the beams 100 are typically H-shaped steel. The H-shaped steel is formed by welding an upper wing plate 101, a web plate 102 and a lower wing plate 103, and connecting holes 104 are arranged on the connecting nodes of the upright post 200 and the web plate 102 of the cross beam 100 in an array mode. In order to ensure that all of the attachment holes 104 are aligned, an adjustment gap of 10-15mm is typically maintained between the end face of the cross beam 100 and the post 200. Because of this adjustment gap, the hanger 51 can be removed from the end face of the upper wing plate 101, and the presence of the hanger 51 does not affect the mounting of the cross member 100.

Refer to fig. 14. As can be seen in fig. 14, the spreader is not placed in the middle of the beam 100. Under the action of the torsion spring 40 and the turntable 20, the pull rope 50 is in a pulled-back state, and the distance between the two hooks 51 is smaller than the length of the cross beam 100.

S2: two hooks 51 are hooked to both ends of the cross member 100, respectively.

Refer to fig. 15. As can be seen from fig. 15, in the process of pulling the hook 51 to hook the cross beam 100, the pull rope 50 drives the turntable 20 to rotate 90 degrees anticlockwise, and the lifting appliance moves to the middle position of the cross beam 100.

Since the two rope passing holes 24 are symmetrically arranged about the center line of the turntable 20, the winding reel 30 and the pull rope 50 constitute an automatic centering mechanism. In the process of pulling the hooks 51, the two sections of the pull ropes 50 are synchronously pulled outwards, and the distances from the two hooks 51 to the center of the turntable 20 are the same. When the two hooks 51 are hooked on both ends of the cross beam 100, respectively, the center of the hanger is automatically moved to the middle position (center of gravity) of the cross beam 100. Thus, the center of gravity of the lifting hook 90 coincides with the center of gravity of the cross beam 100, so that centering is realized, and the problem that the cross beam 100 is easy to skew during lifting is fundamentally solved.

With continued reference to fig. 11-12. Note that: the direction of rotation of the turntable 20 in fig. 11-12 is clockwise due to the opposite view direction. As can be seen from fig. 11 to 12, in the centering process, the rotating hook 60 rotates clockwise by 180 °, the hook plate 62 rotates from the unhooking position to the hooking position, and hooks on the bottom of the upper wing plate 101, thus automatically achieving the hooking of the cross beam 100.

If the pull cord 50 is not long enough, the pawl 22 is disengaged from the ratchet 32 and the spool 30 is then rotated counterclockwise to properly pay out a length of the pull cord 50 from the spool 31.

S3: assuming that the unidirectional rotation direction of the ratchet 32 is clockwise, the reel 30 is rotated clockwise, and the four rotating hooks 60 are driven to rotate counterclockwise synchronously until the hooking position is reached.

The cross beam 100 may have different lengths, and after the hook 51 is hooked on the cross beam 100, the pull rope 50 is too long and can not drive the turntable 20 to rotate anticlockwise, or the rotation angle is very small, so that the hook plate 62 cannot rotate to the hook position. At this time, the take-up reel 30 needs to be rotated clockwise.

Two functions of clockwise rotation of the winding disc 30 are provided, namely, the winding pull rope 50 is wound, so that the rotary disc 20 is rotated 90 degrees anticlockwise, and the hook plate 62 can be rotated to a hook position; and secondly, the torque of the torsion spring 40 on the turntable 20 is increased, and enough power is reserved for the later unhooking action. Because the ratchet 32 cooperates with the pawl 22 to enable unidirectional rotation of the take-up reel 30 relative to the turntable 20, the take-up reel 30 does not reverse when it is released.

The cross beam 100 is then hoisted by a crane. Since the center of gravity of the hook 90 coincides with the center of gravity of the cross beam 100, the cross beam 100 is in a horizontal state during lifting, and no skew occurs.

S4: after being in place, the two hooks 51 are then removed.

Refer to fig. 16. After the beam 100 is hoisted in place, a constructor fixes bolts in the connecting holes 104, and the beam 100 is installed. Since the hanger 51 also possibly bears the lifting force of the crane, some of the lifting ropes 80 may be suitably loosened by the crane. Then, the constructor takes the hook 51 off the end of the cross beam 100 by hand.

After the hook 51 is removed from the cross beam 100, the pulling force of the pull rope 50 on the turntable 20 is lost. Under the action of the torsion spring 40, the turntable 20 rotates clockwise by 90 ° and drives the four rotating hooks 60 to rotate clockwise by 180 °. At this time, the hook plate 62 is moved from the hooking position to the unhooking position, and the hooking to the cross beam 100 is released, so that the automatic unhooking is realized. Finally, the hanger is lifted off the beam 100 by a crane, thereby completing the lifting.

The pull cord 50 extends over a long length, which is not conducive to field management. Therefore, when not in use, the pulling rope 50 can be wound up through the winding disc 30, and the hook 51 is clamped on the rope passing plate 13.

The parts not described in detail are prior art. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Claims (8)

1. A unhook hoist that is used for steel to construct crossbeam hoist and mount, characterized by: comprising the following steps:

the plate body is provided with a chute corresponding to the upper wing plate of the cross beam;

the lifting rope is connected with the plate body;

the rotating disc is arranged on the plate body and is provided with a pawl, a driving belt pulley and two rope passing holes, and the two rope passing holes are symmetrically arranged about the central line of the rotating disc;

the torsion spring is arranged between the turntable and the plate body and is used for applying torque to the turntable;

the winding disc is coaxially arranged on the turntable and is provided with a rope winding disc and a ratchet wheel; the ratchet wheel is matched with the pawl, and the unidirectional rotation direction of the ratchet wheel is the same as the direction of the torsion spring applying torque to the turntable;

the middle part of the pull rope is wound on the winding disc, and the rope outlet lengths of the two rope outlet parts are the same; the two rope outlet parts respectively penetrate through the two rope passing holes, and hooks are fixed at the end heads of the rope outlet parts;

the synchronous rotating mechanism comprises a synchronous belt and four rotating hooks; the rotary hook is arranged on the plate body, a driven belt pulley and a hook plate are arranged on the rotary hook, and the driven belt pulley is connected with the driving belt pulley through a synchronous belt;

when the two hooks are respectively hooked at the two ends of the cross beam, the four rotary hooks are driven to synchronously rotate through the pull ropes and the turntables, so that the hook plates are rotated to the hook positions; when the hook is taken down, under the action of the torsion spring, the four rotary hooks reversely rotate, so that the hook plate rotates to the unhooking position.

2. The unhook hoist for steel beam hoisting of claim 1, characterized in that: the carousel is installed in the central part of plate body, and four rotating hooks are rectangular array and are installed in the four corners of carousel.

3. The unhook hoist for steel beam hoisting of claim 1, characterized in that: a tensioning wheel is arranged on the plate body and is used for tensioning the synchronous belt.

4. The unhook hoist for steel beam hoisting of claim 1, characterized in that: a limiting block is fixed on the plate body and used for limiting the rotation angle of the rotating hook.

5. The unhook hoist for steel beam hoisting of claim 1, characterized in that: the rope winding disc is provided with a radial through hole, the pull rope penetrates through the radial through hole, and the midpoint part of the pull rope is fixed on the central line of the rope winding disc through the wire clamp.

6. The unhook hoist for steel beam hoisting of claim 1, characterized in that: the center distance of the two rope passing holes is larger than the diameter of the driving belt pulley, and the diameter of the driving belt pulley is larger than the diameter of the driven belt pulley.

7. The unhook hoist for steel beam hoisting of claim 1, characterized in that: a rod piece is fixed on the turntable, the center of the rod piece is positioned on the center line of the turntable, and two rope passing holes are formed at two ends of the rod piece.

8. A hoisting method of a beam is characterized in that: the method comprises the following steps:

s1: the unhooking lifting appliance is arranged on the cross beam, and can slide along the cross beam through the cooperation of the sliding chute and the upper wing plate;

s2: two hooks are respectively hooked at two ends of the cross beam; if the pulling rope is not long enough, the pawl is disengaged from the ratchet wheel, and the pulling rope is released from the winding disc;

s3: setting the unidirectional rotation direction of the ratchet wheel as a clockwise direction; the winding disc is rotated clockwise to drive the four rotating hooks to synchronously rotate anticlockwise until reaching the hooking position; then, the cross beam is horizontally hoisted by a crane;

s4: after the cross beam is installed in place, loosening the lifting rope through the crane, and then taking down the two hooks; at this time, the four rotating hooks rotate clockwise to reach the unhooking position; finally, the unhooking lifting appliance is lifted off the cross beam through the crane.