Tower crane luffing rope tensioning system and tower crane

Abstract

This invention provides a luffing rope tensioning system for a tower crane and the tower crane itself. The luffing rope tensioning system includes a luffing trolley and a luffing drum. The luffing trolley includes a frame for detachable installation at the base of the tower crane's jib, and a tensioning device and connector fixedly connected to the frame. The tensioning device includes a tensioning wheel. A long luffing rope and a short luffing rope are connected to both ends of the luffing drum. The long luffing rope passes through a jib tip pulley located at the jib tip of the tower crane and connects to the connector. The short luffing rope passes through a jib root pulley located at the jib root of the tower crane and connects to the tensioning wheel. The tensioning wheel can rotate to tension the short luffing rope. This system uses a manually driven tensioning device to tension the short luffing rope and a mechanically driven luffing drum to tension the long luffing rope, effectively reducing the tension force required for manually tensioning the short luffing rope and significantly reducing the labor intensity of operators using the luffing rope tensioning system.

Description

Technical Field

[0001] This invention belongs to the field of tower crane technology, and particularly relates to a luffing rope tensioning system for a tower crane and the tower crane itself. Background Technology

[0002] With the development of the construction industry, ease of operation and safety have become a common understanding and pursuit in the tower crane industry. At present, the industry generally adopts the luffing rope tensioning method. The luffing rope tensioning device is an auxiliary component of the tower crane luffing trolley. By tensioning the luffing rope, the luffing trolley and the hook below it can move back and forth along the boom direction, thereby achieving the purpose of tower crane lifting and transporting goods. Luffing ropes are prone to stretching and sagging under stress during use. Luffing rope tensioning devices prevent this slack by maintaining tension, ensuring the luffing rope remains taut and allowing the tower crane's luffing trolley to operate normally. However, existing tower crane luffing rope tensioning devices require multiple adjustments to the tensioning wheel's rotation angle during tensioning, which is time-consuming and poses safety hazards when using crowbars. Furthermore, the current tensioning process is labor-intensive, relying on a single lever transmission and requiring significant tensioning force, especially when the jib is long and the luffing rope is thick, making the tensioning work particularly strenuous and lacking in ergonomics. Therefore, existing tower crane luffing rope tensioning devices cannot meet the needs of practical use, and there is an urgent need for improved technology to solve these problems. Summary of the Invention

[0003] The main objective of this invention is to propose a luffing rope tensioning system for tower cranes and a tower crane in general, aiming to solve the technical problems of large tensioning force and certain safety risks required by existing tower crane luffing rope tensioning systems.

[0004] To achieve the above objectives, the present invention provides a luffing rope tensioning system, wherein the luffing rope tensioning system includes:

[0005] The luffing trolley includes a frame for detachable mounting at the jib root of a tower crane, and a tensioning device and connector fixedly connected to the frame, the tensioning device including a tensioning wheel; and

[0006] The luffing drum has a luffing long rope and a luffing short rope connected to its two ends respectively. The luffing long rope passes through the boom tip pulley located at the boom tip of the tower crane and is connected to the connector. The luffing short rope passes through the boom root pulley located at the boom root and is connected to the tensioning wheel. The tensioning wheel can rotate to tension the luffing short rope.

[0007] In this embodiment of the invention, the rotation direction of the first drum of the luffing drum can pull the luffing trolley toward the arm tip pulley, and the rotation of the luffing drum along the rotation direction of the first drum can tension the luffing rope.

[0008] In this embodiment of the invention, the tensioning device further includes a rotating shaft and a U-shaped lug plate. The U-shaped lug plate includes two side plates fixedly connected to the frame. The tensioning wheel is clamped in the U-shaped groove between the two side plates. The rotating shaft passes through the tensioning wheel and the two side plates.

[0009] In this embodiment of the invention, the tensioning wheel includes a ratchet, a middle wheel, and an outer wheel distributed along the axial direction. The outer diameters of the ratchet and the outer wheel are both larger than the outer diameter of the middle wheel, so that a rope-winding groove is formed on the tensioning wheel around the outer peripheral wall of the middle wheel.

[0010] In this embodiment of the invention, the tensioning device further includes a ratchet stop, which cooperates with the ratchet to keep the luffing rope taut.

[0011] In this embodiment of the invention, the tensioning device further includes a wrench, one end of which is sleeved on the rotating shaft, and the other end of which extends out a ratchet push rod for pushing the teeth of the ratchet to rotate.

[0012] In this embodiment of the invention, the outer wall of the outer wheel is provided with a rope end fixing part and a rope through hole, and the end of the variable amplitude short rope wound in the rope winding groove passes through the rope through hole and is connected to the rope end fixing part.

[0013] In this embodiment of the invention, the rope end fixing part includes a connecting block and a protective cover. The connecting block is fixedly disposed on the outer side wall of the outer wheel, and the protective cover covers the connecting block and is used to guide the luffing short rope through the rope through hole.

[0014] In this embodiment of the invention, the luffing rope tensioning system of the tower crane further includes a support roller for preventing the luffing long rope or luffing short rope from sagging. The support roller is disposed between the luffing drum and the boom tip pulley or boom root pulley.

[0015] In an embodiment of the present invention, a tower crane is also provided, which includes the luffing rope tensioning system of the tower crane as described above.

[0016] Through the above technical solution, the luffing rope tensioning system for tower cranes provided in this embodiment of the invention has the following beneficial effects:

[0017] Before operation, the luffing rope tensioning system of this invention requires the rotation of the luffing drum to bring the luffing trolley with the luffing short rope to the base of the tower crane's boom. Then, the rotation of the luffing drum tensions the luffing long rope. Once the long rope is nearly horizontal, the luffing mechanism stops, completing the tensioning of the long rope. Finally, a tensioning device is used to tension the luffing short rope. Because the luffing short rope requires less tension than the luffing long rope, and in situations where the luffing drum cannot simultaneously tension both ropes, this system uses a manually driven tensioning device to tension the short rope and a mechanically driven luffing drum to tension the long rope. This effectively reduces the tension required for manually tensioning the short rope, significantly reducing the labor intensity of operators using the luffing rope tensioning system. Furthermore, the system's structure is simple, easy to install, and cost-effective.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the luffing rope tensioning system of a tower crane according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the luffing trolley according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the tensioning device according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the tensioning device when connected to the luffing short rope according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of a wrench according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the assembly structure of the wrench during operation according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures

[0027] label name label name 10 frame 211 ratchet 31 luffing long rope 212 Middle wheel 32 Amplitude short rope 213 outer wheel 30 luffing drum 11 wrench 20 tensioning device 24 Ratchet stop 21 Tensioner 112 short round steel 22 Rotation axis 40 Through the rope hole 23 Side panel 251 Connecting block 50 Roller 252 Protective cover 12 connector 60 Arm root pulley 70 Arm tip pulley 25 Rope end fixing part 13 Connecting plate 111 Ratchet push rod 214 Rope loop groove Detailed Implementation

[0028] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] The luffing rope tensioning system of the tower crane according to the present invention is described below with reference to the accompanying drawings.

[0030] like Figure 1 As shown, in an embodiment of the present invention, a luffing rope tensioning system for a tower crane is provided. The luffing rope tensioning system for the tower crane includes a luffing trolley and a luffing drum 30. The luffing trolley includes a frame 10 for detachable installation at the root of the boom of the tower crane, and a tensioning device 20 and a connector 12 fixedly connected to the frame 10. The tensioning device 20 includes a tensioning wheel 21. The two ends of the luffing drum 30 are respectively connected to a long luffing rope 31 and a short luffing rope 32. The long luffing rope 31 passes through a boom tip pulley 70 located at the boom tip of the tower crane and is connected to the connector 12. The short luffing rope 32 passes through a boom root pulley 60 located at the boom root of the boom and is connected to the tensioning wheel 21. The tensioning wheel 21 can rotate to tension the short luffing rope 32.

[0031] When the luffing mechanism of the tower crane is working, the luffing drum 30 can rotate and pull the luffing long rope 31 or the luffing short rope 32 to move the luffing trolley towards the boom tip pulley 70 or the boom root pulley 60. However, in the luffing rope tensioning system of the present invention, when tensioning the luffing short rope 32 and the luffing long rope 31, the luffing trolley needs to be fixedly connected to the boom root of the crane by the connecting plate 13 on the frame 10. This way, the luffing trolley will not move when tension is applied to the luffing long rope 31 and the luffing short rope 32.

[0032] After the trolley is fixed, the end connected to the boom root pulley 60 is the short luffing rope 32, and the end connected to the boom tip pulley 70 is the long luffing rope 31. Since the luffing trolley is fixed at the end closest to the boom root pulley 60, the length of the short luffing rope 32 is shorter than the length of the long luffing rope 31. The sag formula for the wire rope is: F = qnL 2 / 8fh, where F is the tension force of the wire rope; n is the number of wires in the wire rope; q is the linear density of the wire rope; and fh is the sag of the wire rope. From the above formula for wire rope sag, it can be seen that the required tension force of the wire rope is directly proportional to its length. Therefore, it can be deduced that the tension force required to tension the luffing short rope 32 is much smaller than the tension force required to tension the luffing long rope 31. When the luffing drum cannot simultaneously tension both the luffing short rope 32 and the luffing long rope 31, this system uses a manually driven tensioning device 20 to tension the luffing short rope 32 and a mechanically driven luffing drum 30 to tension the luffing long rope 31. This effectively reduces the tension force required to manually tension the luffing short rope 32, significantly reduces the labor intensity of operators using the luffing rope tensioning system, and the system's structure is simple, easy to arrange, and has a low cost.

[0033] It should be noted that the luffing drum can only be tensioned by rotating either the luffing short rope 32 or the luffing long rope 31. When tensioning the luffing short rope 32, the luffing long rope 31 will loosen, and when tensioning the luffing long rope 31, the luffing short rope 32 will loosen. Therefore, a tensioning device 20 must be added to tension the luffing short rope.

[0034] In this embodiment of the invention, the rotation direction of the first drum of the luffing drum 30 can pull the trolley toward the boom tip pulley 70, and the rotation of the luffing drum 30 along the first drum rotation direction can tension the luffing rope 31. Specifically, when the luffing trolley is fixed at the root of the boom, since the luffing rope 31 cannot pull the frame 10, the rotation of the luffing drum 30 along the first drum rotation direction can tension the luffing rope 31; when the luffing trolley is not fixed, the rotation of the luffing drum 30 along the first drum rotation direction can pull the luffing trolley closer to the boom tip, and similarly, the rotation of the luffing drum 30 along the first drum rotation direction can pull the luffing trolley closer to the boom root.

[0035] In embodiments of the present invention, such as Figure 3 As shown, the tensioning device 20 also includes a rotating shaft 22 and a U-shaped lug. The U-shaped lug includes two side plates 23 that are fixedly connected to the frame 10. The tensioning wheel 21 is clamped in the U-shaped groove between the two side plates 23. The rotating shaft 22 passes through the tensioning wheel 21 and the two side plates 23. The tensioning wheel is hinged to the frame by the U-shaped lug. The structure is simple, practical and highly stable.

[0036] In this embodiment of the invention, the tensioning wheel 21 includes a ratchet 211, a middle wheel 212, and an outer wheel 213 distributed along the axial direction. The outer diameters of the ratchet 211 and the outer wheel 213 are both larger than the outer diameter of the middle wheel 212, so that a rope-winding groove 214 is formed on the tensioning wheel 21 around the outer peripheral wall of the middle wheel 212. The presence of the rope-winding groove 214 makes the variable amplitude short rope 32 stably and orderly wound around the outer peripheral wall of the middle wheel 212 one turn at a time, preventing the variable amplitude short rope 32 from coming off the tensioning wheel 21 and causing rotational tensioning failure.

[0037] In this embodiment of the invention, the tensioning device 20 further includes a ratchet stop 24, which cooperates with the ratchet 211 to keep the luffing rope 32 taut. Specifically, as shown... Figure 3 As shown, the ratchet stop 24 is pivotally mounted on the frame 10 and has a protrusion that engages with the ratchet 211. With the ratchet stop 24 blocking it, the ratchet 211 can only rotate in the direction of tensioning the luffing rope 32, and cannot rotate in the direction of slackening the luffing rope 32. This prevents the luffing rope 32 with tension from pulling the tensioning wheel 21 in the direction of slackening and drooping the luffing rope 32, thus ensuring that the luffing rope 32 is in a state of continuous tension.

[0038] In this embodiment of the invention, the tensioning device 20 further includes a wrench 11, one end of which is sleeved on the rotating shaft 22, and the other end extends out with a ratchet push rod 111 for rotating the teeth of the ratchet 211. Figure 5 and Figure 6 As shown, the wrench 11 also includes a short round steel bar 112 that can engage with the teeth of the ratchet 211. In operation, one end of the wrench 11 is first fitted onto the rotating shaft 22, and the short round steel bar 112 is inserted into the tooth groove of the ratchet 211 and engages with the teeth. Then, simply hold the ratchet push rod 111 of the wrench 11 to rotate the wrench 11 around the axis of the rotating shaft 22. The short round steel bar 112 will push the teeth of the ratchet 211, causing the tension wheel 21 to rotate synchronously with the wrench 11. During this process, based on fundamental theorems in physics, the torque of the wrench 11 rotating is equal to the torque of the tension wheel 21 rotating. Since the radius of the tension wheel 21 is much smaller than the length of the wrench 11, and given that length and force are inversely proportional when torque is constant, the force on the wrench 11 is much less than the force required for the tension wheel 21 to rotate. Therefore, the wrench 11 is used to assist in rotating the tension wheel 21, reducing the operator's workload, and is simple, convenient, and labor-saving.

[0039] In this embodiment of the invention, when the luffing rope tensioning system of the tower crane is in a non-operating state, such as Figure 2 As shown, the wrench 11 is detachably mounted on the frame. When tensioning is required, the operator can take out the wrench 11 to assist in rotating the tensioning wheel 21.

[0040] In this embodiment of the invention, the outer wall of the outer wheel 213 is provided with a rope end fixing part 25 and a rope through hole 40. The end of the variable amplitude short rope 32 wound in the rope winding groove 214 passes through the rope through hole 40 and connects to the rope end fixing part 25. Figure 4 As shown, this connection method allows the luffing rope 32 to be more securely connected to the tensioning wheel 21. Specifically, when the tensioning wheel 21 rotates to tension the luffing rope 32, most of the reaction tension of the luffing rope 32 on the tensioning wheel 21 will be transferred to the outer peripheral wall of the rope through hole 40, and only a small part will become the pressure between the end of the luffing rope 32 and the rope end fixing part 25. This reduces the tension of the luffing rope 32 on the connection of the rope end fixing part 25, prevents the end connection from being unstable due to excessive tension of the luffing rope 32, and reduces the risk of wire rope breakage.

[0041] In this embodiment of the invention, the rope end fixing part 25 includes a connecting block 251 and a protective cover 252. The connecting block 251 is fixedly disposed on the outer side wall of the outer wheel 213. The protective cover 252 covers the connecting block 251 and is used to guide the luffing short rope 32 through the rope through hole 40. Moreover, the protective cover 252 and the outer wheel 213 clamp the ends of the connecting block 251 and the luffing short rope 32 together, so that the luffing short rope 32 cannot be disengaged from the connection with the connecting block 251, thereby improving the connection stability of the luffing short rope 32.

[0042] In this embodiment of the invention, the luffing rope tensioning system of the tower crane further includes a support roller 50 for preventing the luffing long rope 31 or luffing short rope 32 from sagging. The support roller 50 is disposed between the luffing drum 30 and the boom tip pulley 70 or the boom root pulley 60. When the tension of the luffing long rope 31 or luffing short rope 32 is insufficient, the support roller 50 lifts the luffing rope to prevent the sagging of the luffing rope from interfering with the components on the boom and affecting the normal operation of the boom.

[0043] In an embodiment of the present invention, a tower crane is also proposed, which includes the luffing rope tensioning system of the tower crane as described above. Since the crane adopts all embodiments of the luffing rope tensioning system of the tower crane described above, it has the beneficial effects brought about by all the embodiments described above.

[0044] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A luffing rope tensioning system for a tower crane, characterized in that, The luffing rope tensioning system of the tower crane includes: The luffing trolley includes a frame (10) for detachable mounting at the jib root of a tower crane, and a tensioning device (20) and a connector (12) fixedly connected to the frame (10), the tensioning device (20) including a tensioning wheel (21); and A luffing drum (30) is connected to a luffing long rope (31) and a luffing short rope (32) at its two ends. The luffing long rope (31) passes through the boom tip pulley (70) located at the boom tip of the tower crane and is connected to the joint (12). The luffing short rope (32) passes through the boom root pulley (60) located at the boom root of the crane and is connected to the tensioning wheel (21). The tensioning wheel (21) can rotate to tension the luffing short rope (32). When the luffing trolley is fixed at the base of the boom, the luffing drum (30) rotates in the direction of rotation of the first drum to tension the luffing long rope (31), and the tensioning wheel (21) rotates to tension the luffing short rope (32).

2. The luffing rope tensioning system for a tower crane according to claim 1, characterized in that, The first drum rotation direction of the luffing drum (30) can pull the luffing trolley toward the arm tip pulley (70), and the rotation of the luffing drum (30) along the first drum rotation direction can tension the luffing rope (31).

3. The luffing rope tensioning system for a tower crane according to claim 1, characterized in that, The tensioning device (20) further includes a rotating shaft (22) and a U-shaped lug. The U-shaped lug includes two side plates (23) fixedly connected to the frame (10). The tensioning wheel (21) is clamped in the U-shaped groove between the two side plates (23). The rotating shaft (22) passes through the tensioning wheel (21) and the two side plates (23).

4. The luffing rope tensioning system for a tower crane according to claim 3, characterized in that, The tensioning wheel (21) includes a ratchet (211), an intermediate wheel (212), and an outer wheel (213) distributed along the axial direction. The outer diameters of the ratchet (211) and the outer wheel (213) are both larger than the outer diameter of the intermediate wheel (212), so that a rope-winding groove is formed on the tensioning wheel (21) around the outer peripheral wall of the intermediate wheel (212).

5. The luffing rope tensioning system for a tower crane according to claim 4, characterized in that, The tensioning device (20) further includes a ratchet stop (24), which cooperates with the ratchet (211) to keep the amplitude rope (32) taut.

6. The luffing rope tensioning system for a tower crane according to claim 4, characterized in that, The tensioning device (20) also includes a wrench (11), one end of which is sleeved on the rotating shaft (22), and the other end extends out with a push rod (111) for rotating the teeth of the ratchet (211).

7. The luffing rope tensioning system for a tower crane according to claim 4, characterized in that, The outer wall of the outer wheel (213) is provided with a rope end fixing part (25) and a rope through hole (40). The end of the variable amplitude short rope (32) wound in the rope winding groove passes through the rope through hole (40) and is connected to the rope end fixing part (25).

8. The luffing rope tensioning system for a tower crane according to claim 7, characterized in that, The rope end fixing part (25) includes a connecting block (251) and a protective cover (252). The connecting block (251) is fixedly disposed on the outer side wall of the outer wheel (213). The protective cover (252) covers the connecting block (251) and is used to guide the luffing short rope (32) to the rope through hole (40).

9. The luffing rope tensioning system for a tower crane according to claim 1, characterized in that, The luffing rope tensioning system of the tower crane also includes a support roller (50) for preventing the luffing long rope (31) or the luffing short rope (32) from sagging. The support roller (50) is disposed between the luffing drum (30) and the boom tip pulley (70) or the boom root pulley (60).

10. A tower crane, characterized in that, The tower crane includes the luffing rope tensioning system of the tower crane according to any one of claims 1 to 9.

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