Tower crane reverse auxiliary lowering mechanism and its lowering method

Abstract

The present invention relates to a reverse auxiliary lowering mechanism for a tower crane and a lowering method thereof. The mechanism includes a moving trolley that is limitedly movable along the length direction of the middle balance arm of the tower crane, and a rope guiding mechanism for guiding the rope of the original hoisting winch in the tower crane to the moving trolley and forming a moving traction along with the moving trolley. The rope guiding mechanism is fixed relative to the balance arm. The moving trolley is provided with a guide wheel for guiding the rope, and the rope is in a downward vertical traction state after passing through the guide wheel. The lowering method is as follows: A moving trolley and a rope guiding mechanism are arranged on one side of the balance arm of the tower crane, so as to facilitate the use of the rope of the original hoisting winch in the tower crane for the hoisting operation on the balance arm side. When the balance arm rotates to be in the same direction as the introduction direction of the standard section introduction platform of the tower crane, the lowering operation of the tower crane on the balance arm side can be realized. The balance arm is usually shorter than the boom, so it is not easy to interfere with the building, which is convenient for the lowering operation, has high efficiency, saves time and effort, and has low cost.

Description

Technical Field

[0001] The present invention relates to the field of tower cranes in construction equipment, and is a reverse auxiliary lowering mechanism for a tower crane and a lowering method thereof. Background Art

[0002] A tower crane, also known as a tower hoist, is mainly used for material hoisting work on construction sites. Generally, it needs to be installed on site at the beginning of excavation and removed after the main structure is capped. According to the safety operation regulations for tower crane jacking operations, when the tower crane is jacking and lowering, the boom must be in the same direction as the standard section introduction platform of the climbing sleeve frame. Due to the structural design limitations of the climbing sleeve frame of the tower crane, the boom of the tower crane must face the same direction during jacking and lowering operations. During jacking, since the boom of the tower crane is above the building, the tower crane jacking operation will not be affected by building interference; however, during the disassembly and lowering operation, the boom of the tower crane needs to be lowered below the building roof. If the lowering operation space considered during the early installation is affected by building structure adjustment and the construction of new buildings in nearby sections, the tower crane will not be able to perform the conventional lowering operation according to the safety operation regulations for jacking operations. In such cases, the conventional solution is to use a heavy-duty truck crane to assist in directly removing the tower crane in the air above the building. At this time, it is necessary to solve the problems of parking the heavy-duty truck crane on the basement roof and the safety risks of high-altitude disassembly operations of the tower crane. Not only will the economic cost of tower crane disassembly increase, but the safety hazards of high-altitude disassembly are also very large. Therefore, it is necessary to improve the existing tower crane lowering structure and operation method. Summary of the Invention

[0003] To overcome the above deficiencies, the purpose of the present invention is to provide a reverse auxiliary lowering mechanism for a tower crane and a lowering method thereof to the art, so as to solve the technical problems that when the existing tower crane is lowered, it is difficult to perform conventional lowering operations due to interference on the boom side, and it is necessary to cooperate with mechanical auxiliary equipment for lowering, which is inconvenient, time-consuming, laborious, and costly. The purpose is achieved through the following technical solutions.

[0004] An anti - direction auxiliary lowering mechanism for a tower crane, the key structural points of which are that the anti - direction auxiliary lowering mechanism includes a moving trolley that moves in a limited manner along the length direction of the middle balance arm of the tower crane, and a wire guiding mechanism for guiding the rope of the original hoisting winch of the tower crane to the moving trolley and forming a moving traction along with the moving trolley. The wire guiding mechanism is fixed relative to the balance arm. The moving trolley is provided with a guide wheel for guiding the rope, and the rope is in a downward vertical traction state after passing through the guide wheel. Compared with the prior art, in the above - mentioned structure, a moving trolley and a wire guiding mechanism are arranged on one side of the balance arm of the tower crane, so as to facilitate the use of the rope of the original hoisting winch of the tower crane for hoisting operations on the balance - arm side. When the balance arm rotates to the same direction as the introduction direction of the standard - section introduction platform of the tower crane, the lowering operation of the tower crane on the balance - arm side can be realized. The balance arm is usually shorter than the boom, so it is not easy to interfere with the building, which is convenient for the lowering operation. Since auxiliary machinery such as a heavy - duty truck crane is eliminated, the lowering operation is more efficient, time - saving and labor - saving, and the cost is lower.

[0005] The balance arm of the tower crane includes symmetric left brackets, right brackets, and an intermediate bracket fixed between the left bracket and the right bracket. The left bracket and the right bracket are both channel - steel brackets with openings facing outward. The moving trolley includes a left roller frame and a right roller frame that are limited in the respective slots of the left bracket and the right bracket and form a rolling fit along the slots, and a self - locking motor that is in driving connection with one of the rollers in the left roller frame or the right roller frame. The self - locking motor is fixed relative to the left roller frame or the right roller frame. A roller shaft bracket located below the balance arm is fixedly connected between the left roller frame and the right roller frame. A roller shaft is provided in the middle of the roller shaft bracket, and the relatively rotatable guide wheel is arranged. Through this structure, the reliable movement of the moving trolley relative to the balance arm is realized, and the locking of the moving trolley can also be realized according to the locking of the self - locking motor.

[0006] The roller shaft bracket includes symmetric left angle steel plates and right angle steel plates. The left ends of the left angle steel plates and the right ends of the right angle steel plates are both welded with sealing plates, and are respectively detachably fixed to the left roller frame and the right roller frame through bolts by the sealing plates. The roller shaft is welded between the included - angle openings of the left angle steel plate and the right angle steel plate. The guide wheel is connected to the part of the roller shaft between the left angle steel plate and the right angle steel plate, that is, the guide wheel is limited between the left angle steel plate and the right angle steel plate. Through this structure, the roller shaft bracket is relatively stable and reliable, not easy to deform, and at the same time, it is convenient to disassemble and assemble with the left roller frame and the right roller frame for use.

[0007] One of the rollers provided on the left roller frame and the right roller frame is a gear, and the corresponding channel - steel bracket in the balance arm is provided with straight teeth distributed linearly along the slot. The gear meshes with the straight teeth. Through this structure, the movement and locking of the moving trolley relative to the balance arm are more reliable.

[0008] The wire guiding mechanism includes an upper wire guiding bracket, a lower wire guiding bracket, an upper guiding roller, and a lower guiding roller. The upper wire guiding bracket is fixed above the balance arm and is provided with an upper guiding roller that rotates in a positioned manner. The lower wire guiding bracket is fixed below the balance arm and is provided with a lower guiding roller that rotates in a positioned manner. The rotation axes of the upper guiding roller and the lower guiding roller are parallel to that of the guide wheel. The rope of the hoisting winch of the tower crane passes through the upper guiding roller, the lower guiding roller, and the guide wheel of the moving trolley in sequence. Through this structure, the rope of the hoisting winch can be reliably guided to the moving trolley.

[0009] The rope is connected to a hook after passing through the guide wheel of the moving trolley. Through this structure, the hoisting operation on the balance arm side is facilitated.

[0010] When the moving trolley moves to one end of the balance arm, the moving trolley is located above the standard section introduction platform of the climbing sleeve frame in the tower crane. Through this structure, the hoisting operation at the standard section introduction platform can be facilitated.

[0011] The method for the lowering operation of the reverse auxiliary lowering mechanism of this tower crane includes the following steps:

[0012] Step 1, according to the requirements of lowering on the balance arm side, conduct a counterweight operation on one side of the boom of the tower crane. Lift the counterweight block with the lifting tool on the original boom side of the tower crane, and fix the counterweight block to the moving trolley on one side of the boom through a binding rope. Drive the counterweight block to move along the length direction of the boom by controlling the moving trolley to achieve the balance between the boom and the balance arm.

[0013] Step 2, disassemble the rope connected to the hoisting winch of the original tower crane for hoisting operation, that is, disassemble the rope connected to the above-mentioned lifting tool on one side of the boom, change the rope to be connected to the wire guiding mechanism and the moving trolley of the reverse auxiliary lowering mechanism, and connect the end of the rope to a hook for hoisting the standard section.

[0014] Step 3, rotate the balance arm and the boom of the tower crane, and rotate the balance arm to be in the same direction as the introduction direction of the standard section introduction platform of the tower crane itself.

[0015] Step 4, utilize the climbing sleeve frame of the tower crane to cooperate with the jacking cylinder to work, disassemble the standard section corresponding to the standard section introduction platform in the tower crane and export it above the standard section introduction platform. After export, the tower crane descends by the height of one standard section through the climbing sleeve frame cooperating with the jacking cylinder.

[0016] Step 5, by controlling the rope of the hoisting winch and the moving trolley, make the rope and the hook located above the standard section introduction platform, control the hook of the rope to lift the standard section on the standard section introduction platform, and continue to control the moving trolley and the hoisting winch to lift the standard section to the ground. The above completes one lowering operation, and by cycling in this way, all the lowering operations of the tower crane are realized.

[0017] The counterweight block in the first step is two standard sections. After the standard sections are lifted by the lifting appliance and moved close to the movable trolley, the movable trolley, the lifting appliance and the standard sections are moved along the boom to be close to the climbing sleeve frame. Then, ropes are manually operated at the climbing sleeve frame to fasten the two standard sections to the movable trolley. That is, the movable trolley relies on the ropes to suspend the standard sections, and the ropes of the hoisting winch are no longer stressed. By this means, the stress on the original hoisting ropes of the tower crane is released, facilitating the removal of the ropes.

[0018] By adjusting the layout of the tower crane, the present invention enables the tower crane to quickly adjust the boom side lowering section to the counterweight arm side lowering section as needed, thus having a wider application range, more convenient and efficient lowering operation, reducing the difficulty and cost of lowering, and being suitable for use as a reverse auxiliary lowering mechanism for various tower cranes or an improvement of the same type of lowering operation method. Brief Description of the Drawings

[0019] Figure 1 It is a schematic diagram of a partial structure during the lowering process of the tower crane of the present invention.

[0020] Figure 2 It is a schematic diagram of the installation state structure of the counterweight arm and the movable trolley of the present invention.

[0021] Figure 3 is Figure 2 A schematic diagram of the completed installation structure.

[0022] Figure 4 It is a schematic diagram of the use state of the reverse lowering of the tower crane of the present invention Figure 1 .

[0023] Figure 5 It is a schematic diagram of the use state of the reverse lowering of the tower crane of the present invention Figure 2 .

[0024] Figure 6 It is a schematic diagram of the use state of the reverse lowering of the tower crane of the present invention Figure 3 .

[0025] The numbers and names in the figures are: 1, tower crane; 101, boom; 102, movable trolley; 2, counterweight arm; 201, left support; 202, right support; 203, middle support; 3, hoisting winch; 4, upper guide rope support; 5, upper guide roller; 6, lower guide rope support; 7, lower guide roller; 8, movable trolley; 801, left roller frame; 802, right roller frame; 803, self-locking motor; 804, roller; 805, left angle steel plate; 806, right angle steel plate; 807, sealing plate; 808, roller shaft; 809, guide wheel; 9, climbing sleeve frame; 10, standard section introduction platform; 11, standard section. Detailed Embodiments

[0026] Now, in combination with the drawings, the present invention will be further described.

[0027] As Figures 1 - 3 shown, the reverse auxiliary tower crane lowering mechanism is an improved design based on the existing tower crane 1 with the function of lifting and lowering the tower section on the side of the boom. It mainly includes a moving trolley 8 that moves in a limited position along the length of the counter jib 2 of the tower crane, and a wire guiding mechanism for guiding the ropes of the original hoisting winch 3 in the tower crane to the moving trolley and forming a moving traction with the moving trolley. The wire guiding mechanism is fixed relative to the counter jib. The moving trolley is provided with a wire guiding wheel 809 for guiding the ropes, and the ropes are in a vertically downward traction state after passing through the wire guiding wheel.

[0028] The counter jib 2 of the above-mentioned tower crane 1 includes symmetric left brackets 201 and right brackets 202, and an intermediate bracket 203 welded and fixed between the left bracket and the right bracket. Among them, both the left bracket and the right bracket are channel steel brackets with openings facing outward, and the intermediate bracket is a steel plate and / or a square column. The moving trolley 8 includes a left roller frame 801 and a right roller frame 802 that are limited in the respective slots of the left bracket and the right bracket and form a rolling fit along the slots. Each of the left roller frame and the right roller frame is provided with at least one set of rollers 804. Among them, a self-locking motor 803 is fixedly connected to the outside of the left roller frame or the right roller frame, and the self-locking motor forms a transmission fit with a set of rollers on the corresponding side, that is, the motor drives the rollers to rotate. A roller shaft bracket is fixedly connected between the left roller frame and the right roller frame and is located below the counter jib. The roller shaft bracket includes symmetric left angle steel plates 805 and right angle steel plates 806. The left end of the left angle steel plate and the right end of the right angle steel plate are both welded with sealing plates 807, and are detachably fixed to the left roller frame and the right roller frame through the sealing plates by bolts respectively. A roller shaft 808 is welded between the included angle openings of the left angle steel plate and the right angle steel plate. A wire guiding wheel 809 is axially connected to the roller shaft part between the left angle steel plate and the right angle steel plate, that is, the wire guiding wheel is limited between the left angle steel plate and the right angle steel plate. With the above structure, the self-locking motor drives the rollers, and the rollers drive the moving trolley to move along the counter jib, and the self-locking motor relies on the self-locking function to lock the position of the moving trolley relative to the counter jib.

[0029] In order to make the movement of the moving trolley 8 relative to the counter jib 2 more reliable and stable, one of the rollers 804 provided on the above-mentioned left roller frame 801 and right roller frame 802 is a gear, and the corresponding channel steel bracket in the counter jib is provided with straight teeth distributed linearly along the slot. Through the meshing of the gear and the straight teeth, a more reliable transmission is realized, and when the self-locking motor locks, the meshing and locking of the gear and the straight teeth are more reliable.

[0030] The above-mentioned wire guiding mechanism includes an upper wire guiding support 4, a lower wire guiding support 6, an upper guiding roller 5, and a lower guiding roller 7. The upper wire guiding support is fixed above the balance arm 2 by bolts or welding and is provided with a freely rotating upper guiding roller. The lower wire guiding support is fixed below the balance arm 2 by bolts or welding and is provided with a freely rotating lower guiding roller. The rotating axes of the upper guiding roller and the lower guiding roller are parallel to the rotating axis of the guide wheel 809. The rope of the hoisting winch of the tower crane passes through the upper guiding roller and the lower guiding roller in sequence for transmission and guiding to the guide wheel of the moving trolley, and after passing through the guide wheel, the rope is connected to a hook for hoisting the standard.

[0031] The moving stroke of the above-mentioned moving trolley 8 is limited as follows: when the moving trolley moves to one end of the balance arm 2, the moving trolley is located above the standard section introduction platform of the climbing sleeve of the tower crane; when the moving trolley moves to the other end of the balance arm, it is sufficient to ensure that the hoisted standard section is separated from above the standard section introduction platform.

[0032] Based on the above structure, combined with Figures 4 - 6 , the reverse lowering operation steps of the tower crane are described as follows:

[0033] Step 1, according to the requirements of lowering the section on the balance arm 2 side, conduct a counterweight operation on the original boom 101 side of the tower crane 1. Use the lifting device on one side of the tower crane boom to lift two standard sections 11 of the tower crane, and lift the standard sections close to the moving trolley 102. Then control the moving trolley to move the lifting device and the two standard sections close to the climbing sleeve 9 of the tower crane. At this time, the standard sections are directly stressed by the moving trolley, and the rope of the hoisting winch 3 of the tower crane is no longer stressed, which is convenient for the disassembly of this rope. By controlling the moving trolley to drive the standard sections to move along the length direction of the boom, the balance between the boom and the balance arm is adjusted.

[0034] Step 2, disassemble the rope connected to the hoisting winch 3 for the hoisting operation on the boom 101 side, and change the rope to be connected to the wire guiding mechanism and the moving trolley 8 of the reverse auxiliary lowering mechanism. That is, after the rope is led out from the hoisting winch, it passes through the upper guiding roller 5 and the lower guiding roller 7 of the wire guiding mechanism in sequence, and finally passes through the guide wheel 809 of the moving trolley, and connect the end of the rope to the hook for hoisting the standard section 11.

[0035] Step 3, rotate the balance arm 2 and the boom 101 of the tower crane 1 to rotate the balance arm in the same direction as the introduction direction of the standard section introduction platform 10 of the tower crane itself.

[0036] Step 4, use the climbing sleeve 9 of the tower crane 1 itself in cooperation with the jacking cylinder to work, disassemble the standard section 11 corresponding to the standard section introduction platform 10 of the tower crane and export it above the standard section introduction platform. After export, the tower crane descends by the height of one standard section through the cooperation of the climbing sleeve and the jacking cylinder.

[0037] Step 5: By controlling the rope of the hoisting winch 3 and the moving trolley 8, position the rope and the hook above the standard section introduction platform 10, control the hook of the rope to lift the standard section 11 of the standard section introduction platform, and continue to control the moving trolley and the hoisting winch to lift the standard section to the ground. The above completes one lowering operation, and by repeating this cycle, all the lowering operations of the tower crane are realized.

[0038] The above content is intended to illustrate the technical means of the present invention and does not limit the technical scope of the present invention. Obvious improvements made by those skilled in the art in combination with the existing common general knowledge also fall within the protection scope of the claims of the present invention.

Claims

1. A reverse auxiliary lowering mechanism for a tower crane, characterized in that the reverse auxiliary lowering mechanism includes a moving trolley (8) that moves in a limited manner along the length direction of the balance arm (2) in the tower crane (1), and a wire guiding mechanism for guiding the rope of the original hoisting winch (3) in the tower crane to the moving trolley and forming a moving traction along with the moving trolley. The wire guiding mechanism is fixed relative to the balance arm. The moving trolley is provided with a guide wheel (809) for guiding the rope, and the rope is in a downward vertical traction state after passing through the guide wheel; the balance arm of the tower crane includes symmetric left brackets (201), right brackets (202), and an intermediate bracket (203) fixed between the left bracket and the right bracket. Among them, both the left bracket and the right bracket are channel steel brackets with openings facing outward. The moving trolley includes a left roller frame (801) and a right roller frame (802) that are limited in the respective slots of the left bracket and the right bracket and form a rolling fit along the slots, and a self-locking motor (803) that is drivingly connected to one of the rollers (804) in the left roller frame or the right roller frame. The self-locking motor is fixed relative to the left roller frame or the right roller frame. A roller shaft bracket is fixedly connected between the left roller frame and the right roller frame and is located below the balance arm. A roller shaft (808) is provided in the middle of the roller shaft bracket, and the relatively rotatable guide wheel (809) is provided.

2. The reverse auxiliary lowering mechanism for a tower crane according to claim 1, characterized in that the roller shaft bracket includes symmetric left angle steel plates (805) and right angle steel plates (806). The left ends of the left angle steel plates and the right ends of the right angle steel plates are both welded with sealing plates (807), and are detachably fixed to the left roller frame and the right roller frame respectively through the sealing plates by bolts. The roller shaft (808) is welded between the included angle openings of the left angle steel plate and the right angle steel plate. The roller shaft part between the left angle steel plate and the right angle steel plate is connected to the guide wheel (809), that is, the guide wheel is limited between the left angle steel plate and the right angle steel plate.

3. The reverse auxiliary lowering mechanism for a tower crane according to claim 1, characterized in that one of the rollers (804) provided on the left roller frame (801) and the right roller frame (802) is a gear, and the corresponding channel steel bracket in the balance arm (2) is provided with straight teeth distributed linearly along the slot. The gear meshes with the straight teeth.

4. The reverse auxiliary lowering mechanism for a tower crane according to claim 1, characterized in that the wire guiding mechanism includes an upper wire guiding bracket (4), a lower wire guiding bracket (6), an upper guiding roller (5), and a lower guiding roller (7). The upper wire guiding bracket is fixed above the balance arm (2) and is provided with a positioning rotating upper guiding roller. The lower wire guiding bracket is fixed below the balance arm and is provided with a positioning rotating lower guiding roller. The rotating axes of the upper guiding roller, the lower guiding roller and the guide wheel (809) are parallel. The rope of the hoisting winch (3) of the tower crane (1) passes through the upper guiding roller, the lower guiding roller and the guide wheel of the moving trolley (8) in sequence.

5. The reverse auxiliary lowering mechanism for a tower crane according to claim 1, characterized in that the rope is connected to a hook after passing through the guide wheel (809) of the moving trolley (8).

6. The reverse auxiliary lowering mechanism of tower crane according to claim 1, characterized in that when the moving trolley (8) moves to one end of the counter jib (2), the moving trolley is located above the standard section introduction platform (10) of the climbing sleeve frame (9) in the tower crane (1).

7. A lowering method using the reverse auxiliary lowering mechanism of tower crane according to claim 1, characterized in that it includes the following steps: Step 1, according to the requirement of lowering the tower crane on the counter jib (2) side, conduct a counterweight operation on the boom (101) side of the tower crane (1). Lift the counterweight block by the lifting tool on the original boom side of the tower crane, and fix the counterweight block to the movable trolley (102) on the original boom side through a binding rope. Drive the counterweight block to move along the length direction of the boom by controlling the movable trolley to achieve the balance between the boom and the counter jib; Step 2, disassemble the rope connected to the original tower crane hoisting winch (3) for hoisting operation, that is, disassemble the rope connected to the lifting tool on the boom (101) side, and change the rope to be connected to the guide rope mechanism and the moving trolley (8) of the reverse auxiliary lowering mechanism, and connect the end of the rope to the hook for hoisting the standard section (11); Step 3, rotate the counter jib and the boom of the tower crane, and rotate the counter jib to be in the same direction as the introduction direction of the standard section introduction platform of the tower crane itself; Step 4, use the climbing sleeve frame (9) of the tower crane itself to cooperate with the lifting cylinder to work, disassemble the standard section corresponding to the standard section introduction platform in the tower crane and export it above the standard section introduction platform. After export, the tower crane descends by the height of one standard section through the cooperation of the climbing sleeve frame and the lifting cylinder; Step 5, by controlling the rope of the hoisting winch and the moving trolley (8), make the rope and the hook located above the standard section introduction platform, control the hook of the rope to lift the standard section on the standard section introduction platform, and continue to control the moving trolley and the hoisting winch to lift the standard section to the ground. The above completes one lowering operation, and by cycling in this way, all the lowering operations of the tower crane are realized.

8. The lowering method of the reverse auxiliary lowering mechanism of tower crane according to claim 7, characterized in that the counterweight block in Step 1 is two sections of the standard section (11). After the standard section is lifted by the lifting tool and is close to the movable trolley (102), move the movable trolley, the lifting tool and the standard section together along the boom to be close to the climbing sleeve frame (9), and then manually operate the binding rope at the climbing sleeve frame to fasten the two sections of the standard section and the movable trolley. That is, the movable trolley realizes the suspension of the standard section by relying on the binding rope, and the rope of the hoisting winch (3) is no longer stressed.

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