A hoisting method for profiled steel

Abstract

The present invention discloses a hoisting method for profiled steel, aiming to solve the deficiencies that trial hoisting is required during the hoisting process of profiled steel, which reduces work efficiency and the stability during the hoisting process is poor. The invention includes the following steps: S1, move the hoisting equipment to the profiled steel hoisting position; a hoisting rope is arranged on the hoisting equipment; S2, connect a hoisting tooling to the hoisting rope, the hoisting tooling includes a hoisting seat, two pulling ropes symmetrically connected to the hoisting seat, and two hoisting heads, and the two pulling ropes are respectively connected to the two hoisting heads; S3, respectively connect the two hoisting heads to both ends of the profiled steel; S4, start the hoisting equipment to hoist the profiled steel, the profiled steel rises and laterally moves to the target position, and the profiled steel remains balanced during the rising and moving process; S5, when the profiled steel is hoisted to the target position and the profiled steel is lowered in place, remove the hoisting heads, and the hoisting equipment hoists the hoisting tooling and lowers it to prepare for the hoisting of the next profiled steel. During the hoisting process of the profiled steel, the smooth hoisting operation of the profiled steel can be ensured without trial hoisting.

Description

Technical Field

[0001] The invention relates to a hoisting technology, and more specifically, to a method for hoisting section steel. Background Art

[0002] At present, during the construction of the frame, it is necessary to use lifting equipment to lift the steel. During the lifting process, the lifting rope is first connected to the steel, and then the lifting equipment works to lift the steel. After moving it to the appropriate position, the steel is lowered and the lifting rope is removed. After that, the steel is fastened to the frame. Since the steel is long and narrow, the center of gravity needs to be kept in the vertical direction during the lifting process to ensure stability. Therefore, an inverted Y-shaped lifting rope is often used. The lower ends of the lifting rope are respectively connected to the two ends of the steel, and the upper end of the lifting rope is connected to the lifting equipment. However, in the actual operation process, the connection position of the lifting rope and the steel is not accurately grasped. In order to ensure the stable lifting of the steel, trial lifting and adjustment are often required, which reduces work efficiency. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings, the present invention provides a method for hoisting steel sections, which can ensure smooth hoisting operation of the steel sections without the need for trial hoisting, thereby ensuring the safety of hoisting and being conducive to improving work efficiency.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: a method for hoisting a steel section, comprising the following steps:

[0005] S1, move the lifting equipment to the steel lifting position; set the lifting rope on the lifting equipment;

[0006] S2, connecting a lifting tool to the lifting rope, the lifting tool comprising a lifting seat, two pull ropes symmetrically connected to the lifting seat, and two lifting heads, the two pull ropes are respectively connected to the two lifting heads;

[0007] S3, connect the two lifting heads to the two ends of the steel respectively;

[0008] S4, the lifting equipment starts to lift the steel section, the steel section rises upward and moves horizontally to the target position, and the steel section maintains balance during the lifting and moving process;

[0009] S5, the steel section is hoisted to the target position. After the steel section is lowered into place, the lifting head is removed, and the lifting equipment is hoisted and lowered with the lifting tooling to prepare for the lifting of the next steel section.

[0010] Before lifting the steel section, the lifting device is connected to the lifting rope, and the two lifting heads on the lifting device are connected to the two ends of the steel section respectively. Since the weight of the steel section is basically uniform along the length direction, the center of gravity of the steel section is close to the middle position, and the lifting heads are connected to the two ends of the steel section to maintain the balance of the steel section during the lifting process. No trial lifting is required before lifting, which can ensure the smooth lifting of the steel section. In addition, no bundling operation is required during the lifting of the steel section, which avoids scratches on the surface of the steel section caused by bundling, and the elimination of the bundling action can improve work efficiency. This method of lifting steel section does not require trial lifting during the lifting process of the steel section to ensure the smooth lifting operation of the steel section, ensures the safety of the lifting, and is conducive to improving work efficiency.

[0011] Preferably, the lifting head is provided with a positioning groove for inserting the steel section; in S3, the positioning groove on the lifting head is connected to both ends of the steel section.

[0012] The positioning groove is connected to the end of the steel section, and the connection is convenient and reliable, which is beneficial to improving the connection speed between the lifting head and the steel section.

[0013] Preferably, a positioning plate is installed on the side wall of the positioning groove, and a positioning spring is installed between the positioning plate and the lifting head; in S3, under the action of the positioning spring, the end of the positioning plate abuts against the outer wall of the steel section to position the steel section.

[0014] The positioning spring provides clamping force to the positioning plate, and the positioning plate always abuts against the surface of the steel section, thereby achieving a reliable connection between the lifting head and the steel section and preventing the lifting head from slipping off the steel section.

[0015] Preferably, the end edge of the positioning plate placed in the positioning groove includes an abutment section and two guide sections respectively arranged on both sides of the abutment section, and the guide sections are inclined; in S3, the abutment section abuts against the side wall of the steel section.

[0016] The inclined guide section plays a good guiding role in the process of inserting the steel section into the positioning groove, and the setting of the abutment section makes the abutment between the positioning plate and the surface of the steel section more reliable.

[0017] Preferably, a push rod and a locking rod are installed on the upper part of the lifting head, a reset spring is installed between the push rod and the lifting head, a top tooth is provided on the push rod, a locking block is provided on the locking rod, a locking tooth is provided on the locking block, a locking spring is installed between the locking rod and the lifting head, the push rod extends downward under the action of the reset spring and abuts against the steel section, and under the action of the locking spring, the locking teeth on the locking block are adapted to lock with the top teeth, and one end of the locking rod extends outward from the lifting head; in S3, after the lifting head is connected to the steel section, the locking rod is pressed to separate the locking block from the push rod, the push rod is pushed downward and abuts against the surface of the steel section, and then the locking rod is released, and the locking teeth are adapted to the top teeth to achieve locking of the push rod.

[0018] This structural setting makes the connection between the lifting head and the steel section more reliable, preventing the lifting head from being separated from the steel section, which is conducive to the reliable lifting of the steel section.

[0019] As a preferred embodiment, in the process of S4, the length of the pull rope is automatically adjusted according to the center of gravity of the steel section, so that the lifting process of the steel section is kept horizontal. By automatically adjusting the length of the pull rope, the steel section is kept horizontal during the lifting process, and the steel section is prevented from tilting, which causes the lifting head to separate from the steel section, thereby ensuring the reliable lifting of the steel section and avoiding safety hazards.

[0020] Preferably, a balancing slide is installed on the lifting seat, touch switches are installed at both ends of the balancing slide, a rolling ball is installed in the balancing slide, a plurality of blocking columns are installed on the lifting seat and corresponding to the pull rope, a pushing block is provided on the blocking column, and a plurality of pairs of positioning columns are provided on the lifting seat; the upper end of the pull rope is connected to the lifting seat and passes around the blocking columns in turn, and finally passes through between the positioning columns; a pushing mechanism for pushing the blocking columns to move is installed on the lifting seat; when the center of gravity of the steel section deviates to the right, the right side of the lifting seat tilts downward, and the rolling ball rolls to the right and touches the touch block. When the touch switch is turned on, the pushing mechanism is turned on to push the pushing block on the left stop column to move, the stop column is pushed away from the pull rope, and the pull rope on the left side is stretched until the steel section is in a horizontal position, the rolling ball returns to its position, and the pushing mechanism stops. Similarly, when the center of gravity of the steel section deviates to the left, the left side of the lifting seat tilts downward, the rolling ball rolls to the left and touches the touch switch, which turns on the pushing mechanism to push the pushing block on the right stop column to move, the stop column is pushed away from the pull rope, and the pull rope on the right side is stretched until the steel section is in a horizontal position, the rolling ball returns to its position, and the pushing mechanism stops.

[0021] In most cases during the lifting process of steel sections, the center of gravity is in the middle position. When there is a deviation between the connection position between the lifting head and the steel section or the center of gravity of the steel section itself, the center of gravity of the steel section will shift slightly. At this time, this solution can be used to fine-tune the posture of the steel section.

[0022] The rolling ball rolls in the balancing chute. When the steel section is in a horizontal position, the rolling ball is in the middle of the balancing chute and will not touch the touch switch. When the center of gravity of the steel section deviates to the right, the right side of the lifting seat tilts downward. At this time, the right side of the balancing slide groove tilts downward synchronously with the steel section, the rolling ball rolls to the right in the balancing slide groove and touches the touch switch, the pushing mechanism is turned on to push the pushing block on the left stop column to move, the stop column is pushed away from the pull rope, the pull rope on the left is stretched, thereby causing the left side of the steel section to move downward, and the posture is adjusted to the horizontal direction until the steel section is in a horizontal position, the rolling ball returns to its position, the rolling ball is separated from the touch switch, and the pushing mechanism stops. Similarly, the left side of the lifting seat tilts downward. At this time, the left side of the balancing slide groove tilts downward synchronously with the steel section, the rolling ball rolls to the left in the balancing slide groove and touches the touch switch, the pushing mechanism is turned on to push the pushing block on the right stop column to move, the stop column is pushed away from the pull rope, the pull rope on the right is stretched, thereby causing the right side of the steel section to move downward, and the posture is adjusted to the horizontal direction until the steel section is in a horizontal position, the rolling ball returns to its position, the rolling ball is separated from the touch switch, and the pushing mechanism stops. In this way, the steel section can be automatically adjusted to a horizontal position during lifting, ensuring reliable lifting of the steel section and avoiding safety hazards.

[0023] Preferably, the pushing mechanism includes a driving motor, a rack and a gear. The driving motor is triggered and started by a touch switch. The gear is connected to the output shaft of the driving motor through transmission. The rack and the gear are meshed for transmission. The rack is slidably installed on the lifting seat. A top block is provided on the rack. The top block is provided with an inclined pushing surface. The pushing surface abuts against the pushing block to push the stopper.

[0024] When the rolling ball touches the touch switch, the circuit of the corresponding drive motor is turned on, the drive motor starts to run, and the rack is driven to move through the gear. The top block on the rack abuts against the push block, thereby pushing the blocking column to move and disengage from the pull rope. As the rack continues to move, the blocking column is pushed away from the pull rope in turn, and the pull rope stretches, so that the steel section is adjusted in the horizontal direction. The control of the pushing mechanism is accurate and reliable.

[0025] Another scheme, the pushing mechanism includes a piston cylinder and an abutment block, the abutment block is connected to the telescopic rod of the piston cylinder, the abutment block is provided with an inclined abutment surface, the abutment surface contacts the pushing block and pushes the stopper; the lifting seat includes a fixed seat and a connecting column, the fixed seat is provided with an installation cavity, the installation cavity is installed with a lifting plug and a pre-tensioning spring, the lower end of the connecting column is connected to the lifting plug, the upper end of the connecting column extends out of the installation cavity and is connected to the lifting rope, the pre-tensioning spring abuts against the lifting plug, and solenoid valves are installed between the two piston cylinders and the installation cavity, the solenoid valves are triggered to open by a touch switch, and the installation cavity is filled with hydraulic oil.

[0026] When the rolling ball touches the touch switch, the corresponding solenoid valve opens, and the hydraulic oil in the installation cavity enters the piston cylinder through the solenoid valve, pushing the piston rod outward. The abutment block connected to the piston rod pushes the stop column to move and disengage the pull rope, so that the pull rope is extended. When it is necessary to return to the original position, the two solenoid valves open, and the lifting plug returns to the original position under the action of the preload spring. The gravity of the steel itself provides the lifting plug with the power to move, increasing the pressure of the hydraulic oil, thereby realizing the movement of the piston rod without the need for additional power.

[0027] Compared with the prior art, the present invention has the following beneficial effects: (1) during the steel section lifting process, a trial lifting is not required to ensure the smooth lifting operation of the steel section, thereby ensuring the safety of the lifting and improving work efficiency; (2) during the steel section lifting process, the posture can be automatically adjusted to a horizontal position, thereby ensuring the stability and reliability of the lifting and avoiding safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the hoisting of embodiment 1 of the present invention;

[0029] Figure 2 It is a partial structural schematic diagram of the lifting seat position of embodiment 1 of the present invention;

[0030] Figure 3 It is a schematic diagram of the connection structure between the lifting head and the steel section of the present invention;

[0031] Figure 4 It is a structural schematic diagram of the lifting head of the present invention;

[0032] Figure 5 is a schematic diagram of the hoisting of Embodiment 2 of the present invention;

[0033] Figure 6 It is a partial structural schematic diagram of the lifting seat position of embodiment 2 of the present invention;

[0034] In the figure: 1, crane, 2, lifting seat, 3, pull rope, 4, lifting head, 5, steel, 6, positioning groove, 7, positioning plate, 8, positioning spring, 9, abutment section, 10, guide section, 11, movable groove, 12, limit strip, 13, spring plate, 14, push rod, 15, locking rod, 16, reset spring, 17, top tooth, 18, locking block, 19, locking tooth, 20, locking spring, 21, balance slide, 22, touch switch, 23, rolling ball, 24, stop column, 25, connecting hole, 26, push block, 27, positioning column, 28, rack, 29, gear, 30, top block, 31, piston cylinder, 32, abutment block, 33, fixed seat, 34, connecting column, 35, installation cavity, 36, lifting plug, 37, preload spring, 38, solenoid valve, 39, lifting rope, 40, guide groove. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0036] Example 1: A method for hoisting steel (see attached Figure 1 To Attachment Figure 4 ), including the following steps:

[0037] S1, move the lifting equipment to the steel lifting position; set a lifting rope 39 on the lifting equipment; in this embodiment, the lifting equipment adopts a crane 1;

[0038] S2, connecting a lifting tool to the lifting rope, the lifting tool comprising a lifting seat 2, two pull ropes 3 symmetrically connected to the lifting seat, and two lifting heads 4, the two pull ropes are respectively connected to the two lifting heads; the lifting rope is connected to the lifting seat;

[0039] S3, connect the two lifting heads to the two ends of the steel 5 respectively;

[0040] S4, the lifting equipment starts to lift the steel section, the steel section rises upward and moves horizontally to the target position, and the steel section maintains balance during the lifting and moving process;

[0041] S5, the steel section is hoisted to the target position. After the steel section is lowered into place, the lifting head is removed, and the lifting equipment is hoisted and lowered with the lifting tooling to prepare for the lifting of the next steel section.

[0042] The lifting head is provided with a positioning groove 6 for inserting the steel section; in S3, the positioning groove on the lifting head is connected to both ends of the steel section. A positioning plate 7 is installed on the side wall of the positioning groove, and positioning plates are installed on both side walls of the positioning groove. A positioning spring 8 is installed between the positioning plate and the lifting head; in S3, the end of the positioning plate abuts against the outer wall of the steel section under the action of the positioning spring to position the steel section. The end edge of the positioning plate placed in the positioning groove includes an abutting section 9 and two guide sections 10 respectively arranged on both sides of the abutting section, and the guide sections are inclined; in S3, the abutting section abuts against the side wall of the steel section. The lifting head is provided with an installation groove, and the positioning plate is movably inserted in the positioning groove. The installation groove on the outer wall of the lifting head is provided with installation strips on both upper and lower sides, and a movable groove 11 is formed between the two installation strips. A limiting strip 12 is provided at the outer end of the positioning plate, and the limiting strip is placed in the movable groove and abuts against the outer wall of the lifting head. A spring plate 13 is connected to the installation strip, and the positioning spring abuts between the limiting strip and the spring plate. A lifting hole is provided at the upper end of the lifting head, and a pull rope is connected to the lifting hole.

[0043] A push rod 14 and a locking rod 15 are installed on the upper part of the lifting head, a reset spring 16 is installed between the push rod and the lifting head, a top tooth 17 is provided on the push rod, and the top tooth is in a rack-like structure. A locking block 18 is provided on the locking rod, and a locking tooth 19 is provided on the locking block. A locking spring 20 is installed between the locking rod and the lifting head. The push rod extends downward and abuts against the steel section under the action of the reset spring. Under the action of the locking spring, the locking teeth on the locking block are adapted to lock with the top teeth, and one end of the locking rod extends outward from the lifting head; in S3, after the lifting head is connected to the steel section, the locking rod is pressed to separate the locking block from the push rod, and the push rod is pushed downward and abuts against the surface of the steel section. Thereafter, the locking rod is released, and the locking teeth are adapted to the top teeth to lock the push rod. When the locking rod returns to its original position, push the top rod to move so that the locking teeth are separated from the top teeth, push the locking rod outward, and then release the top rod. The locking teeth on the top rod and the top teeth are adapted to lock, and the locking rod is positioned. Two top rods and two locking rods are arranged, and the operating handle is connected between the ends of the two locking rods extending out of the lifting head.

[0044] During S4, the length of the pull rope is adjusted according to the position of the center of gravity of the steel section, so that the lifting process of the steel section remains horizontal. A balancing slide 21 is installed on the lifting seat. The bottom surface of the balancing slide is low in the middle and high at both ends, and is inclined. The inclination angle is within 2 degrees. Touch switches 22 are installed at both ends of the balancing slide. A rolling ball 23 is installed in the balancing slide. A number of blocking columns 24 are installed on the lifting seat and corresponding to the pull rope. Each pull rope corresponds to a row of blocking columns. A connecting hole 25 is provided above the blocking column on the lifting seat, and a push block 26 is provided on the blocking column. Two pairs of positioning columns 27 are provided on the lifting seat, and the positioning columns are arranged below the blocking columns; the upper end of the pull rope is connected to the connection hole position on the lifting seat and bypasses the blocking columns in turn, and finally passes through between the positioning columns. The pull rope bypasses the blocking columns to form an S-shaped structure; a lifting seat is installed A pushing mechanism is installed to push the blocking column to move; when the center of gravity of the steel section deviates to the right, the right side of the lifting seat tilts down, the rolling ball rolls to the right and touches the touch switch, the pushing mechanism is turned on to push the pushing block on the left blocking column to move, the blocking column is pushed away from the pull rope, the pull rope on the left is extended, until the steel section is in a horizontal position, the rolling ball returns to its position, and the pushing mechanism stops; similarly, when the center of gravity of the steel section deviates to the left, the left side of the lifting seat tilts down, the rolling ball rolls to the left and touches the touch switch, the pushing mechanism is turned on to push the pushing block on the right blocking column to move, the blocking column is pushed away from the pull rope, the pull rope on the right is extended, until the steel section is in a horizontal position, the rolling ball returns to its position, and the pushing mechanism stops. A spring is installed between the blocking column and the lifting head. After the blocking column is pushed and separated from the pull rope, the originally bent pull rope at the position of the blocking column becomes straight, so that the length of the entire pull rope is extended, and the straightened pull rope will block the end of the blocking column. In addition, the pull rope is affected by the gravity of the steel section, so the blocking column will not return to its position when it is blocked by the pull rope. After the steel section is removed, the retaining column is returned to its original position.

[0045] The pushing mechanism includes a driving motor, a rack 28, and a gear 29. The driving motor is triggered and started by a touch switch. The gear is connected to the output shaft of the driving motor. The rack is meshed with the gear for transmission. The rack is slidably mounted on the lifting seat. A top block 30 is provided on the rack. An inclined pushing surface is provided on the top block. The pushing surface abuts against the pushing block to push the stopper. A guide groove 40 corresponding to the rack is provided on the lifting seat. The rack is installed in the guide groove and slides in the guide groove.

[0046] Example 2: A method for hoisting steel (see attached Figure 5 , Attachment Figure 6 ), the steps are similar to those of Example 1, the main difference being that the pushing mechanism in this embodiment includes a piston cylinder 31 and an abutment block 32, the abutment block is connected to the telescopic rod of the piston cylinder, an abutment surface is provided on the abutment block, the abutment surface contacts the pushing block and pushes the stopper; the lifting seat includes a fixed seat 33 and a connecting column 34, the fixed seat is provided with an installation cavity 35, a lifting plug 36 and a preload spring 37 are installed in the installation cavity, the lower end of the connecting column is connected to the lifting plug, the upper end of the connecting column extends out of the installation cavity and is connected to the lifting rope, the preload spring abuts against the lifting plug, and a solenoid valve 38 is installed between the two piston cylinders and the installation cavity, the solenoid valve is triggered to open by a touch switch, and the installation cavity is filled with hydraulic oil. The touch switch is installed on the control circuit where the solenoid valve is located, and the solenoid valve is opened when the touch switch is touched, otherwise the solenoid valve is closed. The liquid inlet end of the solenoid valve is connected to the installation cavity through a pipeline, and the liquid outlet end of the solenoid valve is connected to the piston cylinder through a pipeline.

[0047] When the rolling ball touches the touch switch, the corresponding solenoid valve opens, and the hydraulic oil in the installation cavity enters the piston cylinder through the solenoid valve, pushing the piston rod to move outward, and the abutment block connected to the piston rod pushes the blocking column to move and disengage from the pull rope, causing the pull rope to stretch. When it is necessary to return to the original position, the two solenoid valves open, and the lifting plug returns to the original position under the action of the preload spring. The gravity of the steel section itself provides the lifting plug with the power to move, increasing the pressure of the hydraulic oil, thereby realizing the movement of the piston rod without the need for additional power. The other steps are the same as in Example 1.

[0048] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A lifting method for profiled steel, characterized in that, it includes the following steps: S1, Move the lifting equipment to the lifting position of the profiled steel; a lifting rope is arranged on the lifting equipment; S2, Connect a lifting tooling to the lifting rope. The lifting tooling includes a lifting seat, two symmetrically connected pulling ropes on the lifting seat, and two lifting heads. The two pulling ropes are respectively connected to the two lifting heads; S3, Connect the two lifting heads to the two ends of the profiled steel respectively; S4, Start the lifting equipment to lift the profiled steel. The profiled steel rises and laterally moves to the target position, and remains balanced during the rising and moving process of the profiled steel; S5, When the profiled steel is lifted to the target position and the profiled steel is lowered in place, remove the lifting head. The lifting equipment hangs the lifting tooling and lowers it to prepare for the lifting of the next profiled steel; A balance chute is installed on the lifting seat. Touch switches are installed at both ends of the balance chute. A rolling ball is installed in the balance chute. A number of retaining posts are installed on the lifting seat corresponding to the pulling ropes. A pushing block is arranged on the retaining post. A number of pairs of positioning posts are arranged on the lifting seat; the upper end of the pulling rope is connected to the lifting seat and sequentially bypasses the retaining posts, and finally passes through between the positioning posts; a pushing mechanism for pushing the retaining post to move is installed on the lifting seat; the pushing mechanism includes a piston cylinder and an abutting block, and the abutting block is connected to the piston rod of the piston cylinder; the lifting seat includes a fixed seat and a connecting column. An installation cavity is arranged on the fixed seat. A lifting plug and a pre-tightening spring are installed in the installation cavity. The lower end of the connecting column is connected to the lifting plug. The upper end of the connecting column extends out of the installation cavity and is connected to the lifting rope. The pre-tightening spring abuts against the lifting plug. Solenoid valves are installed between the two piston cylinders and the installation cavity. The solenoid valves are triggered and opened by the touch switches. Hydraulic oil is filled in the installation cavity.

2. A lifting method for profiled steel according to claim 1, characterized in that, a positioning groove for inserting the profiled steel is arranged on the lifting head; in step S3, the positioning groove on the lifting head is connected to the two ends of the profiled steel.

3. A lifting method for profiled steel according to claim 2, characterized in that, a positioning plate is installed on the side wall of the positioning groove, and a positioning spring is installed between the positioning plate and the lifting head; in step S3, under the action of the positioning spring, the end of the positioning plate abuts against the outer wall of the profiled steel to position the profiled steel.

4. A lifting method for profiled steel according to claim 3, characterized in that, the positioning plate placed at the end edge of the positioning groove includes an abutting section and two guiding sections respectively arranged on both sides of the abutting section. The guiding sections are inclined; in step S3, the abutting section abuts against the side wall of the profiled steel.

5. A lifting method for profiled steel according to claim 2, characterized in that, a top rod and a locking rod are installed on the upper part of the lifting head. A return spring is installed between the top rod and the lifting head. A top tooth is arranged on the top rod. A locking block is arranged on the locking rod. A locking tooth is arranged on the locking block. A locking spring is installed between the locking rod and the lifting head. The top rod extends downward under the action of the return spring and abuts against the profiled steel. Under the action of the locking spring, the locking tooth on the locking block is adapted to lock with the top tooth. One end of the locking rod extends out of the lifting head; in step S3, after the lifting head is connected to the profiled steel, press the locking rod to separate the locking block from the top rod. The top rod is pushed downward and abuts against the surface of the profiled steel. Then release the locking rod, and the locking tooth is adapted to lock with the top tooth to lock the top rod.

6. A lifting method for profiled steel according to any one of claims 1 to 5, characterized in that, During the S4 process, the length of the pulling rope is self-adjusted according to the centroid position of the profiled steel, so that the profiled steel remains horizontal during the lifting process.

7. A lifting method for profiled steel according to claim 6, characterized in that, when the centroid of the profiled steel deviates to the right, the right side of the lifting seat inclines downward, the rolling ball rolls to the right and touches the touch switch, the pushing mechanism is activated to push the pushing block on the left retaining column to move, the retaining column is pushed away from the pulling rope, and the left pulling rope extends until the profiled steel is in a horizontal position, the rolling ball returns to its original position, and the pushing mechanism stops; similarly, when the centroid of the profiled steel deviates to the left, the left side of the lifting seat inclines downward, the rolling ball rolls to the left and touches the touch switch, the pushing mechanism is activated to push the pushing block on the right retaining column to move, the retaining column is pushed away from the pulling rope, and the right pulling rope extends until the profiled steel is in a horizontal position, the rolling ball returns to its original position, and the pushing mechanism stops.

8. A lifting method for profiled steel according to claim 7, characterized in that, the abutting block is provided with an inclined abutting surface, and the abutting surface contacts the pushing block and pushes the retaining block.

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