Pre-tightening method for superlift cable, superlift device, and crane

Abstract

A pre-tensioning method for a superlift cable (1), a superlift device and a crane. The method comprises: receiving a superlift cable pre-tensioning command; controlling the luffing mast (2) to rotate to a preset position at which the luffing mast is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism (5) to adjust the reel-out and reel-in amount of the superlift cable (1) to pre-tension the superlift cable (1); locking the winch mechanism (5), and controlling the luffing mast (2) to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable (1), wherein the tension force of the superlift cable (1) when pre-tensioned is less than that of the superlift cable (1) when tensioned.

Description

[0001] The present application claims priority to the Chinese patent application No. 202311119301.1 filed on August 31, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present application relates to the technical field of lifting equipment, and in particular, relates to a pre-tensioning method for a superlift cable, a superlift device and a crane.BACKGROUND

[0003] With the development of cranes, the boom is designed to be longer and longer. However, the height and width of the cross-section of the boom is limited by various factors, resulting in an increase in the slenderness ratio of the boom. This leads to an increase in lateral bending deflection of the boom and a decrease in the stiffness of the boom, restricting the lifting capacity of the crane. Cranes with longer booms typically use superlift devices to solve the above problem.SUMMARY OF THE INVENTION Technical Problem

[0004] The present application provides a pre-tensioning method for a superlift cable, a superlift device and a crane, so as to solve the defect of insufficient pre-tensioning amount when pre-tensioning the superlift cable with a superlift winch in the prior art.Technical Solution

[0005] The present application provides a pre-tensioning method for a superlift cable, wherein a first end of the superlift cable is fixedly connected to a tip section of a boom, the boom is provided with a luffing mast, a first end of the luffing mast is rotatably connected to a base boom section of the boom, a winch mechanism is provided on the luffing mast, a second end of the superlift cable is sequentially wound around a second end of the luffing mast and a first winding structure fixed on the base boom section and then connected to the winch mechanism, and the first end of the luffing mast is located between the first winding structure and the first end of the superlift cable, the method comprises: receiving a superlift cable pre-tensioning command; controlling the luffing mast to rotate to a preset position at which the luffing mast is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism to adjust the reel-out and reel-in amount of the superlift cable to pre-tension the superlift cable; locking the winch mechanism, and controlling the luffing mast to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable, wherein the tension force of the superlift cable when pre-tensioned is less than that of the superlift cable when tensioned.

[0006] According to the pre-tensioning method for the superlift cable provided by the present application, when the luffing mast is in the target position, a difference between an inclination angle of the base boom section and an inclination angle of the tip section reaches a target difference value.

[0007] According to the pre-tensioning method for the superlift cable provided by the present application, a process of obtaining the difference between the inclination angle of the base boom section and the inclination angle of the tip section comprises: obtaining a first inclination angle of the base boom section with respect to a horizontal line and a second inclination angle of the tip section with respect to the horizontal line; determining a difference between the inclination angle of the base boom section and the inclination angle of the tip section according to the first inclination angle and the second inclination angle.

[0008] According to the pre-tensioning method for the superlift cable provided by the present application, the absolute value of the target difference value is less than or equal to 2 degrees.

[0009] According to the pre-tensioning method for the superlift cable provided by the present application, when the luffing mast is in the target position, the luffing mast is perpendicular to the boom.

[0010] According to the pre-tensioning method for the superlift cable provided by the present application, before controlling the luffing mast to rotate relative to the base boom section to a preset position at which the luffing mast is inclined relative to the base boom section, the method further comprises: controlling the boom to rotate to a position at which the boom is inclined relative to a horizontal line according to the superlift cable pre-tensioning command.

[0011] According to the pre-tensioning method for the superlift cable provided by the present application, an included angle between the boom and a horizontal line is 74-80 degrees.

[0012] The present application also provides a pre-tensioning device for a superlift cable, wherein a first end of the superlift cable is fixedly connected to a tip section of a boom, the boom is provided with a luffing mast, a first end of the luffing mast is rotatably connected to a base boom section of the boom, a winch mechanism is provided on the luffing mast, a second end of the superlift cable is sequentially wound around a second end of the luffing mast and a first winding structure fixed on the base boom section and then connected to the winch mechanism, and the first end of the luffing mast is located between the first winding structure and the first end of the superlift cable, the device comprises: a receiving module for receiving a superlift cable pre-tensioning command; a first control module for controlling the luffing mast to rotate to a preset position at which the luffing mast is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism to adjust the reel-out and reel-in amount of the superlift cable to pre-tension the superlift cable; a second control module for locking the winch mechanism, and controlling the luffing mast to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable, wherein the tension force of the superlift cable when pre-tensioned is less than that of the superlift cable when tensioned.

[0013] The present application also provides a crane, comprising a controller configured to perform the aforementioned pre-tensioning method for the superlift cable.

[0014] The crane according to the present invention further comprises: a first inclination sensor configured to measure an included angle between the base boom section and a horizontal line to obtain a first inclination signal, and send the first inclination signal to the controller; a second inclination sensor configured to measure an included angle between the tip section and the horizontal line to obtain a second inclination signal, and send the second inclination signal to the controller. BRIEF DESCRIPTION OF DRAWINGS

[0015] To more clearly illustrate the technical solutions in the present application or in the prior art, the drawings that are needed for describing the embodiments or the related art are briefly introduced below. Apparently, the drawings described below only represent some embodiments of the present application, and those skilled in the art can obtain other drawings from these drawings without creative efforts. FIG. 1 is a structural schematic diagram of a superlift device provided by the present application; FIG. 2 is a flowchart of a pre-tensioning method for a superlift cable provided by the present application; FIG. 3 is a structural schematic diagram of a pre-tensioning device for a superlift cable provided by the present application. Reference numerals:

[0016] 1, superlift cable; 2, luffing mast; 3, first pulley; 4, second pulley; 5, winch mechanism; 6, hydraulic cylinder; α, first preset angle; 7, receiving module; 8, first control module; 9, second control module.DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions, and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings in the present application, and apparently, the described embodiments only represent part of the embodiments of the present application, not all of them. Based on the embodiments described in the present application, all other embodiments obtainable by those skilled in the art without creative work fall within the scope of protection of the present application.

[0018] The pre-tensioning method for the superlift cable of the present application will be described below with reference to FIGS. 1 to 2.

[0019] As shown in FIGS. 1 and 2, in the pre-tensioning method for the superlift cable provided by the embodiments of the present application, the superlift cable 1 needs to have a certain winding mode, specifically, a first end of the luffing mast 2 is rotatably connected to a base boom section of the boom, and an adjustment mechanism is provided between the luffing mast 2 and the base boom section for adjusting the included angle between the luffing mast 2 and the base boom section. The adjustment mechanism may be, but is not limited to, a hydraulic cylinder 6, wherein two ends of the hydraulic cylinder 6 are rotatably connected to the luffing mast 2 and the base boom section, respectively.

[0020] A winch mechanism 5 is provided on the luffing mast 2, a first winding structure is provided on the base boom section, a first end of the superlift cable 1 is fixedly connected to a tip section of a boom, and a second end of the superlift cable 1 is sequentially wound around a second end of the luffing mast 2 and the first winding structure and then connected to the winch mechanism 5. The winch mechanism 5 can reel in and reel out the superlift cable 1. The first end of the luffing mast 2 is located between the first winding structure and the first end of the superlift cable 1.

[0021] A second winding structure may be provided at the second end of the luffing mast for ensuring the stability of the superlift cable 1 wound around the second end of the luffing mast 2.

[0022] The first winding structure and the second winding structure may be, but are not limited to, in a structural form of a pulley, and with reference to FIG. 1, the first winding structure is a first pulley 3, and the second winding structure is a second pulley 4.

[0023] As shown in FIG. 2, based on the above structure, the pre-tensioning method for the superlift cable provided by the embodiments of the present application mainly comprises the following steps: Step 110, receiving a superlift cable pre-tensioning command; Step 120, controlling the luffing mast to rotate to a preset position at which the luffing mast is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism to adjust the reel-out and reel-in amount of the superlift cable to pre-tension the superlift cable. Step 130, locking the winch mechanism, and controlling the luffing mast to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable, wherein the tension force of the superlift cable when pre-tensioned is less than that of the superlift cable when tensioned.

[0024] First of all, through massive data analysis and verification, the applicant found that when the luffing mast 2 rotates in a direction away from the boom, that is, when the luffing mast 2 gradually rotates in a direction that tends to become perpendicular to the boom, the sum of the distance between the first end of the superlift cable 1 and the second pulley 4, the distance between the second pulley 4 and the first pulley 3, and the distance between the first pulley 3 and the winch mechanism 5 gradually increases.

[0025] Specifically, the included angle between the luffing mast 2 and the base boom section is denoted as β, and when the included angle between the luffing mast 2 and the base boom section is β, the sum of the distance between the first end of the superlift cable 1 and the second pulley 4, the distance between the second pulley 4 and the first pulley 3, and the distance between the first pulley 3 and the winch mechanism 5 is denoted as m.

[0026] Taking the situation that the distance between the first end of the superlift cable 1 and the first end of the luffing mast 2 is 80 meters, the distance between the winch mechanism 5 and the first end of the luffing mast 2 is 3 meters, the distance between the second pulley 4 and the winch mechanism 5 is 5 meters, and the distance between the first end of the luffing mast 2 and the first pulley 3 is 10 meters as an example, the correspondence relationship between m and β during the change of β is shown in the following table. Table 1β / (degree)m / (meter)097.01097.52098.53099.640100.750101.660102.370102.980103.490103.6

[0027] In the embodiments of the present application, after receiving the superlift cable pre-tensioning command, it is necessary to first adjust the included angle between the luffing mast 2 and the base boom section to a first preset angle α , and the first preset angle α is greater than or less than 90 degrees, that is, the luffing mast 2 is not perpendicular to the base boom section.

[0028] While adjusting the included angle between the luffing mast 2 and the base boom section, the winch mechanism 5 is used to adjust the reel-out and reel-in amount of the superlift cable 1 to pre-tension the superlift cable 1 and prevent the superlift cable 1 from being too loose.

[0029] In the present embodiment, pre-tensioning refers to adjusting the reel-out and reel-in amount of the superlift cable 1 so that the superlift cable 1 is in a state in which the superlift cable 1 is neither too tight nor too loose, that is, the length of the superlift cable 1 that is not reeled in is slightly larger than the sum of the distances of the path segments travelled by the superlift cable 1.

[0030] After the position of the luffing mast 2 is adjusted, the winch mechanism 5 is locked to ensure that the length of the superlift cable 1 winding and extending between the winch mechanism 5 and the tip section is fixed, that is, the length of the superlift cable 1 that has been reeled out by the winch mechanism 5 is kept constant. Then the luffing mast 2 is rotated in a direction that tends to become perpendicular to the boom. When the luffing mast 2 rotates, the sum of the distance between the first end of the superlift cable 1 and the second pulley 4, the distance between the second pulley 4 and the first pulley 3, and the distance between the first pulley 3 and the winch mechanism 5 gradually increases. Since the length of the superlift cable 1 that has been reeled out by the winch mechanism 5 is kept constant, during the rotation of the luffing mast 2, the superlift cable 1 will gradually be tensioned and generate a certain tension force, thereby completing the pre-tensioning of the superlift cable 1.

[0031] It should be understood that, in the pre-tensioned state, the superlift cable 1 is in a state that is substantially straightened but not fully tensioned. After the winch mechanism 5 is locked, as the luffing mast 2 rotates, the length of the superlift cable 1 gradually approaches or even becomes slightly less than the length of the path it travels, so that the superlift cable 1 is further straightened and tensioned, i.e. the tension force of the superlift cable 1 when pre-tensioned is less than that of the superlift cable when tensioned.

[0032] In this way, when pre-tensioning the superlift cable 1 by using the pre-tensioning method for the superlift cable provided by the embodiments of the present application, instead of relying solely on the pulling force of the winch mechanism 5, the pre-tensioning amount of the superlift cable 1 is skillfully increased by the rotation of the luffing mast 2, wherein the pre-tensioning force that can be provided by the hydraulic cylinder when driving the luffing mast 2 to luff up is fully utilized, which is beneficial for maximizing the lifting capacity of the crane, so as to solve the problem of insufficient pre-tensioning amount when pre-tensioning the superlift cable 1 with a superlift winch in the prior art.

[0033] In addition, in the pre-tensioning method for the superlift cable provided by the present application, in the operation after the winch mechanism 5 is locked, there is no need to add another driving device, and it can be completed only by using the existing adjustment mechanism of the superlift device for driving the luffing of the luffing mast 2, which has the advantages of simple structure and low cost. Moreover, the pre-tensioning of the superlift cable 1 is completed at the same time of the luffing process of the luffing mast 2, thereby reducing the operation steps.

[0034] In some embodiments, when the luffing mast is in the target position, a difference between an inclination angle of the base boom section and an inclination angle of the tip section reaches a target difference value.

[0035] Wherein the inclination angle of the base boom section is an included angle between the base boom section and the horizontal line, and the inclination angle of the tip section is an included angle between the tip section and the horizontal line. The greater the difference between the inclination angle of the base boom section and the inclination angle of the tip section, the greater the bending degree of the boom; the smaller the difference between the inclination angle of the base boom section and the inclination angle of the tip section, the smaller the bending degree of the boom.

[0036] That is, when pre-tensioning the superlift cable 1, it is necessary to control the boom to have a certain bending degree.

[0037] In the step 130, it is necessary to obtain the difference between the inclination angle of the base boom section and the inclination angle of the tip section in real time, and control the rotation of the luffing mast 2 according to the difference between the inclination angle of the base boom section and the inclination angle of the tip section, so as to provide an appropriate pre-tensioning amount to the superlift cable 1.

[0038] Under the action of its own side bending deflection, the difference between the inclination angle of the base boom section and the inclination angle of the tip section is relatively large before the superlift cable 1 is tensioned. While the superlift cable 1 is being pre-tensioned by rotating the luffing mast 2, the superlift cable 1 is gradually tensioned along with the rotation of the luffing mast 2 before the luffing mast 2 is rotated to a position that is perpendicular to the boom, and at the same time, the difference between the inclination angle of the base boom section and the inclination angle of the tip section is gradually reduced, that is, the bending degree of the boom is gradually reduced. When the superlift cable 1 is pre-tensioned, it is sufficient to keep the difference between the inclination angle of the base boom section and the inclination angle of the tip section within a certain range.

[0039] When the difference between the inclination angle of the base boom section and the inclination angle of the tip section is reduced to the target difference value, a rotation stop signal can be sent to control the luffing mast 2 to stop rotating, and the pre-tensioning of the superlift cable 1 is completed.

[0040] In a specific embodiment, the absolute value of the target difference value is less than or equal to 2 degrees, that is, the difference between the inclination angle of the base boom section and the inclination angle of the tip section is controlled to be within the range of -2 degrees to 2 degrees.

[0041] In the present embodiment, when obtaining the difference between the inclination angle of the base boom section and the inclination angle of the tip section, it is necessary to obtain a first inclination angle of the base boom section with respect to a horizontal line and a second inclination angle of the tip section with respect to the horizontal line. Then, the difference between the inclination angle of the base boom section and the inclination angle of the tip section can be determined according to the first inclination angle and the second inclination angle.

[0042] The first inclination angle and the second inclination angle can be obtained by providing inclination sensors at one end of the base boom section away from the tip section and at one end of the tip section away from the base boom section respectively, and using the inclination sensors for measurement.

[0043] In some embodiments, when the luffing mast 2 is in the target position, the luffing mast 2 is perpendicular to the boom. That is, in the step 130, the luffing mast 2 can be directly rotated to a position where the luffing mast 2 is perpendicular to the boom, thereby providing the maximum pre-tensioning amount for the superlift cable 1.

[0044] In this case, if the pre-tensioning amount for the superlift cable 1 is too large when the luffing mast 2 is rotated to a position perpendicular to the boom, it is necessary to redo the pre-tensioning of the superlift cable 1, wherein the value of the first preset angle α is appropriately increased in the step 120. If the pre-tensioning amount for the superlift cable 1 is insufficient when the luffing mast 2 is rotated to a position perpendicular to the boom, it is necessary to redo the pre-tensioning of the superlift cable 1, wherein the value of the first preset angle α is appropriately reduced in the step 120.

[0045] In the embodiments of the present application, before controlling the luffing mast 2 to rotate relative to the base boom section according to the superlift cable pre-tensioning command and controlling the winch mechanism 5 to adjust the reel-out and reel-in amount of the superlift cable 1, that is, before the step 120, it is also needed to control the boom to rotate until the boom is positioned at an angle to the horizontal line, so that the boom is in an inclined state. The included angle between the boom and the horizontal line is denoted as a second preset angle.

[0046] Before pre-tensioning the superlift cable 1 by using the pre-tensioning method for the superlift cable provided by the embodiments of the present application, the bending degree of the boom is also affected by the inclination angle of the boom itself. When the inclination angle of the boom is small, for example, when the axis of the boom is close to being horizontal, the bending degree of the boom is large; when the inclination angle of the boom is large, for example, when the axis of the boom is close to being vertical, the bending degree of the boom is small.

[0047] Therefore, before the step 120, according to the superlift cable pre-tensioning command, a boom state adjustment signal is sent so as to adjust the inclination angle of the boom to a larger value range, which can reduce the required pre-tensioning amount of the superlift cable 1 in the step 130.

[0048] In the present embodiment, the second preset angle is set to be within the range of 74-80 degrees, that is, after the inclination angle of the boom is adjusted to be within the range of 74-80 degrees, the above pre-tensioning operation is performed.

[0049] Specifically, the second preset angle may be set to be 77 degrees.

[0050] In another aspect, based on the same general inventive concept, the embodiments of the present application further provide a pre-tensioning device for a superlift cable, and the pre-tensioning device for the superlift cable described below and the pre-tensioning method for the superlift cable described above can be referred to in correspondence with each other.

[0051] In the pre-tensioning device for the superlift cable provided by the embodiments of the present application, the superlift cable 1 needs to have a certain winding mode, specifically, a first end of the luffing mast 2 is rotatably connected to a base boom section of the boom, and an adjustment mechanism is provided between the luffing mast 2 and the base boom section for adjusting the included angle between the luffing mast 2 and the base boom section. The adjustment mechanism may be, but is not limited to, a hydraulic cylinder 6, wherein two ends of the hydraulic cylinder 6 are rotatably connected to the luffing mast 2 and the base boom section, respectively.

[0052] A winch mechanism 5 is provided on the luffing mast 2, a first winding structure is provided on the base boom section, a first end of the superlift cable 1 is fixedly connected to a tip section of a boom, and a second end of the superlift cable 1 is sequentially wound around a second end of the luffing mast 2 and the first winding structure and then connected to the winch mechanism 5. The winch mechanism 5 can reel in and reel out the superlift cable 1. The first end of the luffing mast 2 is located between the first winding structure and the first end of the superlift cable 1.

[0053] A second winding structure may be provided at the second end of the luffing mast for ensuring the stability of the superlift cable 1 wound around the second end of the luffing mast 2.

[0054] The first winding structure and the second winding structure may be, but are not limited to, in a structural form of a pulley, and with reference to FIG. 1, the first winding structure is a first pulley 3, and the second winding structure is a second pulley 4.

[0055] FIG. 3 is a structural schematic diagram of a pre-tensioning device for a superlift cable provided by the present application.

[0056] As shown in FIG. 3, the pre-tensioning device of the superlift cable comprises: a receiving module 7 for receiving a superlift cable pre-tensioning command; a first control module 8 for controlling the luffing mast to rotate to a preset position at which the luffing mast is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism to adjust the reel-out and reel-in amount of the superlift cable to pre-tension the superlift cable; a second control module 9 for locking the winch mechanism, and controlling the luffing mast to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable, wherein the tension force of the superlift cable when pre-tensioned is less than that of the superlift cable when tensioned.

[0057] In another aspect, based on the same general inventive concept, the embodiments of the present application further provide a crane comprising a controller capable of performing the pre-tensioning method for the superlift cable provided in any one of the above embodiments, thereby realizing automatic pre-tensioning of the superlift cable 1 and reducing manual operation.

[0058] The crane in the embodiments of the present application comprises a boom and a superlift device arranged on the boom, and the superlift device comprises a luffing mast 2, a hydraulic cylinder 6, a first pulley 3, a second pulley 4, a winch mechanism 5, and a superlift cable 1.

[0059] Specifically, the luffing mast 2 is provided on the base boom section of the boom, and a first end of the luffing mast 2 is rotatably connected to the base boom section of the boom. The hydraulic cylinder 6 is arranged between the luffing mast 2 and the base boom section, the cylinder body of the hydraulic cylinder 6 is rotatably connected to the base boom section, the piston rod of the hydraulic cylinder 6 is rotatably connected to the luffing mast 2, and the telescopic action of the hydraulic cylinder 6 can adjust the included angle between the luffing mast 2 and the base boom section.

[0060] The first pulley 3 is provided on the base boom section, and specifically, the first pulley 3 may be provided at one end of the base boom section away from the tip section of the boom.

[0061] The second pulley 4 and the winch mechanism 5 are arranged on the luffing mast 2, the second pulley 4 is arranged at the second end of the luffing mast 2, and the winch mechanism 5 is arranged between the first end of the luffing mast 2 and the second pulley 4.

[0062] The first end of the above superlift cable 1 is fixedly connected to the tip section, and the first end of the luffing mast 2 is located between the first pulley 3 and the first end of the superlift cable 1. The second end of the superlift cable 1 is sequentially wound around the second pulley 4 and the first pulley 3 and then is connected to the winch mechanism 5.

[0063] In the present embodiment, the crane further comprises a first inclination sensor and a second inclination sensor, both of which are electrically connected to the controller.

[0064] The first inclination sensor is configured to measure an included angle between the base boom section and the horizontal line to obtain a first inclination signal, and send the first inclination signal to the controller; and the second inclination sensor is configured to measure an included angle between the tip section and the horizontal line to obtain a second inclination signal, and send the second inclination signal to the controller. The controller may control the action of the hydraulic cylinder 6 according to the received measurement results.

[0065] The device embodiments described above are only illustrative, and some or all of the modules may be selected according to actual needs in order to achieve the purpose of the solution of the embodiments of the present application. It can be understood and implemented by those skilled in the art without creative effort.

[0066] From the above description of embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solutions or those parts thereof that make a contribution to the prior art can be embodied in the form of a software product that may be stored in a computer-readable storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and the software product may comprise a plurality of instructions configured to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or certain parts of the embodiments.

[0067] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions described in the foregoing embodiments can still be modified, or some technical features thereof can be equivalently substituted; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A pre-tensioning method for a superlift cable, wherein a first end of the superlift cable (1) is fixedly connected to a tip section of a boom, the boom is provided with a luffing mast (2), a first end of the luffing mast (2) is rotatably connected to a base boom section of the boom, a winch mechanism (5) is provided on the luffing mast (2), a second end of the superlift cable (1) is sequentially wound around a second end of the luffing mast (2) and a first winding structure fixed on the base boom section and then connected to the winch mechanism (5), and the first end of the luffing mast (2) is located between the first winding structure and the first end of the superlift cable (1), the method comprises: receiving a superlift cable pre-tensioning command; controlling the luffing mast (2) to rotate to a preset position at which the luffing mast (2) is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism (5) to adjust the reel-out and reel-in amount of the superlift cable (1) to pre-tension the superlift cable (1); locking the winch mechanism (5), and controlling the luffing mast (2) to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable (1), wherein the tension force of the superlift cable (1) when pre-tensioned is less than that of the superlift cable (1) when tensioned.

2. The pre-tensioning method for the superlift cable according to claim 1, wherein when the luffing mast (2) is in the target position, a difference between an inclination angle of the base boom section and an inclination angle of the tip section reaches a target difference value.

3. The pre-tensioning method for the superlift cable according to claim 2, wherein a process of obtaining the difference between the inclination angle of the base boom section and the inclination angle of the tip section comprises: obtaining a first inclination angle of the base boom section with respect to a horizontal line and a second inclination angle of the tip section with respect to the horizontal line; determining a difference between the inclination angle of the base boom section and the inclination angle of the tip section according to the first inclination angle and the second inclination angle.

4. The pre-tensioning method for the superlift cable according to claim 2, wherein the absolute value of the target difference value is less than or equal to 2 degrees.

5. The pre-tensioning method for the superlift cable according to any one of claims 1 to 4, wherein when the luffing mast (2) is in the target position, the luffing mast (2) is perpendicular to the boom.

6. The pre-tensioning method for the superlift cable according to any one of claims 1 to 5, wherein before controlling the luffing mast (2) to rotate relative to the base boom section to a preset position at which the luffing mast (2) is inclined relative to the base boom section, the method further comprises: controlling the boom to rotate to a position at which the boom is inclined relative to a horizontal line according to the superlift cable pre-tensioning command.

7. The pre-tensioning method for the superlift cable according to any one of claims 1 to 6, wherein an included angle between the boom and a horizontal line is 74-80 degrees.

8. A pre-tensioning device for a superlift cable, wherein a first end of the superlift cable (1) is fixedly connected to a tip section of a boom, the boom is provided with a luffing mast (2), a first end of the luffing mast (2) is rotatably connected to a base boom section of the boom, a winch mechanism (5) is provided on the luffing mast (2), a second end of the superlift cable (1) is sequentially wound around a second end of the luffing mast (2) and a first winding structure fixed on the base boom section and then connected to the winch mechanism (5), and the first end of the luffing mast (2) is located between the first winding structure and the first end of the superlift cable (1), the device comprises: a receiving module (7) for receiving a superlift cable pre-tensioning command; a first control module (8) for controlling the luffing mast (2) to rotate to a preset position at which the luffing mast (2) is inclined relative to the base boom section according to the superlift cable pre-tensioning command, and controlling the winch mechanism (5) to adjust the reel-out and reel-in amount of the superlift cable (1) to pre-tension the superlift cable (1); a second control module (9) for locking the winch mechanism (5), and controlling the luffing mast (2) to rotate to a target position in a direction that tends to become perpendicular to the boom, so as to tension the superlift cable (1), wherein the tension force of the superlift cable (1) when pre-tensioned is less than that of the superlift cable (1) when tensioned.

9. A crane, comprising a controller configured to perform the pre-tensioning method for the superlift cable according to any one of claims 1-7.

10. The crane according to claim 9, further comprising: a first inclination sensor configured to measure an included angle between the base boom section and a horizontal line to obtain a first inclination signal, and send the first inclination signal to the controller; a second inclination sensor configured to measure an included angle between the tip section and the horizontal line to obtain a second inclination signal, and send the second inclination signal to the controller.

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