Steel truss hoisting gravity center adjusting device and method

Abstract

The invention provides a steel truss hoisting gravity center adjusting device and method. The steel truss hoisting gravity center adjusting device comprises two lifting lugs, a mounting plate, a plurality of positioning frames and a traction assembly. The two lifting lugs are arranged on the steel truss at intervals in the length direction of the steel truss, and the mounting plate is provided with two safety ropes connected with the two lifting lugs respectively. The positioning plates are all arranged on the lower side of the mounting plate, each positioning frame is suitable for being buckled to the upper end face of the steel truss, the two ends of each positioning frame are each connected with a balance weight part, the balance weight parts are detachably connected with the positioning frames, and / or the weight of the balance weight parts is adjustable. And the traction assembly is arranged on the mounting plate and is connected with each positioning frame. In the actual use process, inclination and shaking of the steel truss can be limited in the mode of disassembling the balance weight piece and / or adjusting the weight of the balance weight piece. According to the steel truss hoisting gravity center adjusting device and method, the gravity center of the steel truss can be adjusted, the steel truss is prevented from shaking and inclining in the air, and therefore the safety of a construction site is guaranteed.

Description

Technical Field

[0001] The present application belongs to the technical field of steel truss hoisting, and specifically relates to a steel truss hoisting center of gravity adjustment device and method. Background Art

[0002] Steel trusses are a type of long-span structure made of steel pipes or steel rods, and are often used to build large stadiums, exhibition halls, stations, and other buildings. Steel truss hoisting is the process of installing this structure to a building or a designated location using lifting equipment and hoisting ropes, also known as aerial hoisting or aerial work.

[0003] The inventors have discovered that when erecting and installing lightweight small steel trusses, the steel trusses are prone to swaying in the air due to their small weight and strong winds at high altitudes. Especially when the weights at both ends of the steel trusses are different, the steel trusses may even become unhooked and fall into the construction area, affecting the safety of on-site construction. Summary of the invention

[0004] The embodiments of the present application provide a steel truss hoisting center of gravity adjustment device and method, which are intended to adjust the center of gravity of the steel truss to prevent the steel truss from swaying and tilting in the air, thereby ensuring the safety of the construction site.

[0005] To achieve the above purpose, the technical solution adopted in this application is: A steel truss hoisting center of gravity adjustment device is provided, comprising: Two lifting ears, used for fixing on the steel truss, and arranged at intervals along the length direction of the steel truss; A mounting plate, used for fixing on the lifting equipment, and having two safety ropes suitable for being connected to the two lifting ears respectively; A plurality of positioning frames are arranged at the lower side of the mounting plate and arranged along the length direction of the steel truss; the vertical section of each positioning frame is C-shaped, so as to be buckled on the upper end surface of the steel truss, and the two ends of the positioning frame are respectively located on the two sides of the steel truss; both ends of the positioning frame are connected with counterweights, and the two counterweights can be used to limit the movement of the steel truss in the horizontal direction; and A traction assembly, arranged on the mounting plate and connected to each of the positioning frames, for driving a plurality of the positioning frames to move upwards simultaneously to be separated from the steel truss; Wherein, the counterweight is detachably connected to the positioning frame, and / or the weight of the counterweight is adjustable.

[0006] In a possible implementation, two adjacent positioning frames are fixedly connected, and the traction assembly includes: a rotating roller, disposed on the lower side of the mounting plate, and the rotating roller is connected to the mounting plate in a horizontal rotation direction; and A tension belt, fixedly connected to the outer peripheral wall of the rotating roller and connected to at least one of the positioning frames; Wherein, the rotating roller is transmission-connected with a rotating driving member for driving it to rotate relative to the mounting plate; when the rotating driving member drives the rotating roller to rotate, the tension belt is suitable for being wound around the rotating roller to move the positioning frame upward, or, the tension belt is suitable for being detached from the rotating roller to move the positioning frame downward under the action of its own gravity.

[0007] In a possible implementation, the rotation driving member includes: A rotating motor, fixedly mounted on the upper side of the mounting plate, with its power output axis parallel to the axis of the rotating roller, and its power output end connected to a driving gear; and A driven gear is fixedly connected to the end of the rotating roller and connected to the driving gear, so that when the driving gear rotates, the driven gear drives the rotating roller to rotate synchronously; Among them, the mounting plate has a reserved hole that penetrates in the up and down directions, the reserved hole is located between the driving gear and the driven gear, and a transmission gear is rotatably connected in the reserved hole; the transmission gear is respectively meshed with the driving gear and the driven gear, so that when the driving gear rotates, the transmission gear rotates synchronously, and the transmission gear drives the driven gear to rotate.

[0008] In a possible implementation, the lifting lug includes: A fixing screw rod, which is fixedly arranged on the upper end surface of the steel truss and extends upward; and A hanging piece is threadedly connected to the fixing screw rod, and the hanging piece is suitable for being connected to the safety rope.

[0009] In a possible implementation, the hanging member is provided with a limiting component for abutting against an upper side surface of the positioning frame to limit the upward movement of the positioning frame.

[0010] In a possible implementation, two adjacent positioning frames are fixedly connected, and the limiting assembly includes: a positioning shell, which is fixedly connected to a side of the hanging member facing the positioning frame and has a hollow interior and is open toward the positioning frame; and An alignment plate is slidably inserted in the positioning shell, and a plurality of springs are arranged in parallel between the alignment plate and the inner bottom surface of the positioning shell; Wherein, both ends of each spring are respectively connected to the alignment plate and the positioning shell, so as to drive the alignment plate to extend out of the positioning shell and abut against the upper side surface of the positioning frame.

[0011] In a possible implementation, the hanging component has a positioning hole extending through in a horizontal direction, and the connecting end between the safety rope and the hanging component has a connecting rope in a closed ring shape suitable for passing through the positioning hole.

[0012] In a possible implementation, each of the counterweights is a water bag that is hollow inside and can be filled with water and drained to the outside.

[0013] In one possible implementation, both ends of the positioning frame have a convex shaft extending outward, and the extended end of the convex shaft has an end head extending radially outward; the upper end of the counterweight member has a hanging hole suitable for the convex shaft to pass through so that the end head abuts the outer side surface of the counterweight member.

[0014] In the embodiment of the present application, the lifting equipment can be used to pull and move the steel truss by connecting two safety ropes and two lifting ears on the mounting plate. Based on this, by releasing the positioning frame through the traction assembly, each positioning frame can be moved downward under its own gravity to be buckled on the upper end surface of the steel truss, so that the corresponding two counterweights are respectively on both sides of the steel truss; in this state, the two counterweights can increase the weight of the steel truss when it moves in the air, thereby preventing the steel truss from shaking under the influence of airflow, thereby enhancing the stability of the connection between the lifting ear and the safety rope. At the same time, by controlling the weight of the counterweight on one side, and / or removing part of the counterweight on one side, it can be ensured that the steel truss can remain horizontal in the air.

[0015] Compared with the prior art, the steel truss hoisting center of gravity adjustment device provided in this embodiment can adjust the center of gravity of the steel truss to prevent the steel truss from shaking and tilting in the air, thereby ensuring the safety of the construction site.

[0016] The technical solution adopted in the present application also provides a method for adjusting the center of gravity of a steel truss hoisting, based on the device for adjusting the center of gravity of a steel truss hoisting as described in any of the above items, comprising the following steps: A. Fix the lifting lugs on the steel truss and the mounting plate on the lifting equipment; B. controlling the positioning frame to move in the up and down directions by the traction assembly so that each positioning frame is buckled on the upper end surface of the steel truss; C. lifting the steel truss by the lifting equipment so that a gap appears between the steel truss and the ground; D. Observe the inclination of the steel truss, and make the steel truss level by controlling the weight of the counterweight and / or removing part of the counterweight.

[0017] The beneficial effects of the steel truss hoisting center of gravity adjustment method provided in this embodiment are the same as the beneficial effects of the aforementioned steel truss hoisting center of gravity adjustment device, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A schematic diagram of the three-dimensional structure of a steel truss hoisting center of gravity adjustment device provided in an embodiment of the present application; Figure 2 for Figure 1 A partial enlarged schematic diagram of the upper circle A; Figure 3 This is a schematic structural diagram of the traction assembly and the rotation drive member used in the embodiment of the present application in a combined state; Figure 4 This is a schematic diagram of the exploded structure of the mounting plate and the transmission gear used in the embodiment of the present application; Figure 5 This is a schematic diagram of the exploded structure of the positioning frame and the counterweight member used in the embodiment of the present application; Figure 6 It is a partial enlarged schematic diagram of the lifting lug used in the embodiment of the present application under the explosion perspective; Figure 7 A schematic diagram of the explosion structure of the hoisting parts and safety ropes used in the embodiment of the present application; Figure 8 A schematic diagram of the exploded structure of the limiter assembly used in the embodiment of the present application; Explanation of the reference numerals: 1. Lifting ear; 11. Fixing screw; 12. Lifting piece; 121. Positioning hole; 2. Mounting plate; 21. Safety rope; 211. Connecting rope; 22. Transmission gear; 23. Reserved hole; 3. Positioning frame; 31. Protruding shaft; 311. End; 4. Traction assembly; 41. Rotating roller; 42. Tension belt; 5. Counterweight; 51. Suspension hole; 6. Rotating driving member; 61. Rotating motor; 611. Driving gear; 62. Driven gear; 7. Limiting assembly; 71. Positioning shell; 72. Alignment plate; 721. Spring. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0022] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] Please also read Figures 1 to 8 The steel truss lifting center of gravity adjustment device provided in the present application is now described. The steel truss lifting center of gravity adjustment device provided in the present application comprises two lifting ears 1, a mounting plate 2, a plurality of positioning frames 3 and a traction assembly 4.

[0025] The two lifting ears 1 are used to be fixed on the steel truss and are arranged at intervals along the length direction of the steel truss.

[0026] The mounting plate 2 is used to be fixed on the lifting equipment. In this embodiment, the upper side of the mounting plate 2 has a protrusion extending upward, and the protrusion is used to be connected to the lifting equipment.

[0027] It should be noted that, unlike the board surface of the mounting plate 2 being connected to the lifting equipment, the connection method of the protrusion and the lifting equipment can make the mounting plate 2 more stable in the air.

[0028] Two safety ropes 21 are fixedly connected to the mounting plate 2 and are suitable for being connected to the two lifting ears 1 respectively, so as to realize the combination of the mounting plate 2 and the steel truss.

[0029] Multiple positioning frames 3 are arranged on the lower side of the mounting plate 2 and arranged along the length direction of the steel truss; in this embodiment, the vertical section of each positioning frame 3 is C-shaped, so as to be buckled on the upper end surface of the steel truss, and the two ends of the positioning frame 3 are respectively located on both sides of the steel truss. Counterweights 5 are connected to both ends of the positioning frame 3, and the two counterweights 5 can be used to limit the movement of the steel truss in the horizontal direction.

[0030] The traction assembly 4 is arranged on the mounting plate 2 and connected to each positioning frame 3, so as to drive multiple positioning frames 3 to move upward at the same time to separate from the steel truss, and is also used to release the positioning frames 3, so that each positioning frame 3 moves downward under its own gravity to be engaged with the upper end surface of the steel truss, and the weight of the counterweight 5 is loaded on the steel truss.

[0031] Among them, the counterweight 5 is detachably connected to the positioning frame 3, and / or the weight of the counterweight 5 is adjustable; specifically, this embodiment has three different arrangements: first, the counterweight 5 adopts a weight-adjustable structure, and the counterweight 5 and the positioning frame 3 are fixedly connected; second, the counterweight 5 adopts an ordinary structure, that is, the weight is not adjustable, but the counterweight 5 and the positioning frame 3 are detachably connected; third, the counterweight 5 adopts a weight-adjustable structure, and the counterweight 5 and the positioning frame 3 are detachably connected.

[0032] In the embodiment of the present application, the lifting equipment can be used to pull and move the steel truss by connecting the two safety ropes 21 on the mounting plate 2 with the two lifting ears 1. Based on this, by releasing the positioning frame 3 through the traction assembly 4, each positioning frame 3 can move downward under its own gravity to be buckled on the upper end surface of the steel truss, so that the corresponding two counterweights 5 are respectively on both sides of the steel truss; in this state, the two counterweights 5 can increase the weight of the steel truss when it moves in the air, thereby preventing the steel truss from shaking under the influence of airflow, and further enhancing the stability of the connection between the lifting ear 1 and the safety rope 21. At the same time, by controlling the weight of the counterweight 5 on one side, and / or removing part of the counterweight 5 on one side, it can be ensured that the steel truss can remain horizontal in the air.

[0033] Compared with the prior art, the steel truss hoisting center of gravity adjustment device provided in this embodiment can adjust the center of gravity of the steel truss to prevent the steel truss from shaking and tilting in the air, thereby ensuring the safety of the construction site.

[0034] In some embodiments, Figure 3 As shown, two adjacent positioning frames 3 are fixedly connected so that a plurality of positioning frames 3 form a combination that can move up and down simultaneously.

[0035] Based on this, in the present embodiment, the traction assembly 4 includes a rotating roller 41 and a tension belt 42 .

[0036] The rotating roller 41 is disposed on the lower side of the mounting plate 2 , and the rotating roller 41 is connected to the mounting plate 2 to rotate in a horizontal direction.

[0037] The tension belt 42 is fixedly connected to the outer peripheral wall of the rotating roller 41 and is connected to the positioning frame 3 .

[0038] The rotating roller 41 is drivingly connected to a rotating driving member 6 for driving the rotating roller 41 to rotate relative to the mounting plate 2 .

[0039] By adopting the above technical solution, when the rotating driving member 6 drives the rotating roller 41 to rotate, the tension belt 42 is suitable for being wound around the rotating roller 41 to move the positioning frame 3 upward, or the tension belt 42 is suitable for being detached from the rotating roller 41 to move the positioning frame 3 downward under the action of its own gravity.

[0040] In some embodiments, Figure 3 and Figure 4 As shown, the rotation driving member 6 includes a rotation motor 61 and a driven gear 62 .

[0041] The rotating motor 61 is fixedly arranged on the upper side of the mounting plate 2 , and its power output axis is parallel to the axis of the rotating roller 41 , and its power output end is connected to a driving gear 611 .

[0042] The driven gear 62 is fixedly connected to the end of the rotating roller 41 and is connected to the driving gear 611 , so that when the driving gear 611 rotates, the driven gear 62 drives the rotating roller 41 to rotate synchronously.

[0043] Among them, the mounting plate 2 has a reserved hole 23 that penetrates in the up and down directions, the reserved hole 23 is located between the driving gear 611 and the driven gear 62, and a transmission gear 22 is rotatably connected in the reserved hole 23; this transmission gear 22 is respectively engaged with the driving gear 611 and the driven gear 62, so that when the driving gear 611 rotates, the transmission gear 22 rotates synchronously, and the transmission gear 22 drives the driven gear 62 to rotate.

[0044] In some embodiments, Figure 6 As shown, the lifting eye 1 includes a fixing screw 11 and a lifting member 12 .

[0045] The fixing screw rod 11 is used to be fixedly arranged on the upper end surface of the steel truss, and the fixing screw rod 11 extends upward.

[0046] The hanging member 12 is threadedly connected to the fixing screw rod 11 , and the hanging member 12 is suitable for being connected to the safety rope 21 .

[0047] In some embodiments, Figure 2As shown, the hoisting member 12 is provided with a limit assembly 7 for abutting against the upper side of the positioning frame 3 to limit the upward movement of the positioning frame 3, thereby preventing the positioning frame 3 and the steel truss from separating at high altitude, thereby improving the safety during the construction process.

[0048] In some embodiments, Figure 2 and Figure 8 As shown, two adjacent positioning frames 3 are fixedly connected to form a combination form in which the longitudinal movement of all positioning frames 3 can be restricted by restricting one of the positioning frames 3 .

[0049] Based on this, in this embodiment, the limiting assembly 7 includes a positioning shell 71 and an alignment plate 72 .

[0050] The positioning shell 71 is fixedly connected to a side of the hanging member 12 facing the positioning frame 3 , and has a structure with a hollow interior and an opening facing the positioning frame 3 .

[0051] The alignment plate 72 is slidably inserted in the positioning shell 71 , and a plurality of springs 721 are arranged in parallel between the alignment plate 72 and the inner bottom surface of the positioning shell 71 .

[0052] Among them, the two ends of each spring 721 are respectively connected to the alignment plate 72 and the positioning shell 71, so as to drive the alignment plate 72 to extend out of the positioning shell 71 and abut against the upper side of the positioning frame 3, thereby limiting the upward movement of the positioning frame 3 relative to the steel truss; at the same time, since the positioning frame 3 is buckled on the upper end surface of the steel truss, the steel truss can also limit the downward movement of the positioning frame 3 relative to it; the two are coordinated, and the movement of the positioning frame 3 in the up and down directions is limited.

[0053] It should be supplemented that, in the present embodiment, the side of the alignment plate 72 facing the inside of the positioning shell 71 has a groove into which the spring 721 in an elastic contracted state can be embedded.

[0054] In some embodiments, Figure 7 As shown, the hanging component 12 has a positioning hole 121 penetrating in the horizontal direction, and the connecting end of the safety rope 21 and the hanging component 12 has a connecting rope 211 in a closed ring shape suitable for passing through the positioning hole 121.

[0055] In some embodiments, each counterweight 5 is a water bag that is hollow inside and can be filled with water and drained to the outside; in actual use, the weight of the water bag can be reduced or increased by discharging liquid out of the water bag or injecting liquid into the water bag.

[0056] In some embodiments, Figure 5 As shown, both ends of the positioning frame 3 have a protruding shaft 31 extending outward, and the extended end of the protruding shaft 31 has an end head 311 extending radially outward; the upper end of the counterweight 5 has a hanging hole 51 suitable for the protruding shaft 31 to pass through so that the end head 311 abuts against the outer side of the counterweight 5.

[0057] In this embodiment, the end 311 is made of rubber material and the hanging hole 51 is made of hard material to ensure the stability of the overall structure.

[0058] Based on the same inventive concept, the embodiment of the present application further provides a method for adjusting the center of gravity of a steel truss hoisting, and a device for adjusting the center of gravity of a steel truss hoisting based on any of the above items, comprising the following steps: A. Fix the lifting lug 1 to the steel truss and the mounting plate 2 to the lifting equipment; B. Control the positioning frame 3 to move in the up and down direction through the traction assembly 4, so that each positioning frame 3 is buckled on the upper end surface of the steel truss; C. Lift the steel truss with lifting equipment to create a gap between the steel truss and the ground; D. Observe the inclination of the steel truss, and make the steel truss level by controlling the weight of the counterweight 5 and / or removing part of the counterweight 5.

[0059] The beneficial effects of the steel truss hoisting center of gravity adjustment method provided in this embodiment are the same as the beneficial effects of the aforementioned steel truss hoisting center of gravity adjustment device, which will not be repeated here.

[0060] The above content is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. The steel truss hoisting center of gravity adjustment device is characterized by: include: Two lifting ears, used for fixing on the steel truss, and arranged at intervals along the length direction of the steel truss; A mounting plate, used for fixing on the lifting equipment, and having two safety ropes suitable for being connected to the two lifting ears respectively; A plurality of positioning frames are arranged on the lower side of the mounting plate and arranged along the length direction of the steel truss; the vertical section of each positioning frame is C-shaped, so as to be buckled on the upper end surface of the steel truss, and the two ends of the positioning frame are respectively located on the two sides of the steel truss; both ends of the positioning frame are connected with counterweights, and the two counterweights can be used to limit the movement of the steel truss in the horizontal direction; as well as A traction assembly, arranged on the mounting plate and connected to each of the positioning frames, for driving a plurality of the positioning frames to move upwards simultaneously to be separated from the steel truss; Wherein, the counterweight is detachably connected to the positioning frame, and / or the weight of the counterweight is adjustable.

2. The steel truss hoisting center of gravity adjustment device according to claim 1, characterized in that: Two adjacent positioning frames are fixedly connected, and the traction assembly includes: a rotating roller, disposed on the lower side of the mounting plate, and the rotating roller is connected to the mounting plate in a horizontal rotation direction; and A tension belt, fixedly connected to the outer peripheral wall of the rotating roller and connected to at least one of the positioning frames; Wherein, the rotating roller is transmission-connected with a rotating driving member for driving it to rotate relative to the mounting plate; when the rotating driving member drives the rotating roller to rotate, the tension belt is suitable for being wound around the rotating roller to move the positioning frame upward, or, the tension belt is suitable for being detached from the rotating roller to move the positioning frame downward under the action of its own gravity.

3. The steel truss hoisting center of gravity adjustment device according to claim 2, characterized in that: The rotation driving member comprises: A rotating motor, fixedly mounted on the upper side of the mounting plate, with its power output axis parallel to the axis of the rotating roller, and its power output end connected to a driving gear; and A driven gear is fixedly connected to the end of the rotating roller and connected to the driving gear, so that when the driving gear rotates, the driven gear drives the rotating roller to rotate synchronously; Among them, the mounting plate has a reserved hole that penetrates in the up and down directions, the reserved hole is located between the driving gear and the driven gear, and a transmission gear is rotatably connected in the reserved hole; the transmission gear is respectively meshed with the driving gear and the driven gear, so that when the driving gear rotates, the transmission gear rotates synchronously, and the transmission gear drives the driven gear to rotate.

4. The steel truss hoisting center of gravity adjustment device according to claim 1, characterized in that: The lifting lugs include: A fixing screw rod, which is fixedly arranged on the upper end surface of the steel truss and extends upward; and A hanging piece is threadedly connected to the fixing screw rod, and the hanging piece is suitable for being connected to the safety rope.

5. The steel truss hoisting center of gravity adjustment device according to claim 4, characterized in that: The hanging member is provided with a limiting component for abutting against the upper side surface of the positioning frame to limit the upward movement of the positioning frame.

6. The steel truss hoisting center of gravity adjustment device according to claim 5, characterized in that: Two adjacent positioning frames are fixedly connected, and the limiting assembly includes: a positioning shell, which is fixedly connected to a side of the hanging member facing the positioning frame and has a hollow interior and is open toward the positioning frame; and An alignment plate is slidably inserted in the positioning shell, and a plurality of springs are arranged in parallel between the alignment plate and the inner bottom surface of the positioning shell; Wherein, both ends of each spring are respectively connected to the alignment plate and the positioning shell, so as to drive the alignment plate to extend out of the positioning shell and abut against the upper side surface of the positioning frame.

7. The steel truss hoisting center of gravity adjustment device according to claim 4, characterized in that: The hoisting component is provided with a positioning hole which penetrates in the horizontal direction, and the connecting end of the safety rope and the hoisting component is provided with a connecting rope which is suitable for passing through the positioning hole and is in a closed ring shape.

8. The steel truss hoisting center of gravity adjustment device according to any one of claims 1 to 7, characterized in that: Each of the counterweights is a water bag that is hollow inside and can be filled with water and drained to the outside.

9. The steel truss hoisting center of gravity adjustment device according to any one of claims 1 to 7, characterized in that: Both ends of the positioning frame have outwardly extending convex shafts, and the extended end of the convex shaft has an end head extending radially outward; the upper end of the counterweight has a hanging hole suitable for the convex shaft to pass through so that the end head abuts against the outer side of the counterweight.

10. A method for adjusting the center of gravity of a steel truss hoisting, based on the device for adjusting the center of gravity of a steel truss hoisting according to any one of claims 1 to 9, characterized in that: The following steps are involved: A. Fix the lifting lugs on the steel truss and the mounting plate on the lifting equipment; B. controlling the positioning frame to move in the up and down directions by the traction assembly so that each positioning frame is buckled on the upper end surface of the steel truss; C. lifting the steel truss by the lifting equipment so that a gap appears between the steel truss and the ground; D. Observe the inclination of the steel truss, and make the steel truss level by controlling the weight of the counterweight and / or removing part of the counterweight.

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