Method for replacing luffing cylinder of luffing jib tower crane, and luffing jib tower crane

Abstract

A method for replacing a luffing cylinder of a luffing jib tower crane, and a luffing jib tower crane. The method for replacing a luffing cylinder of a luffing jib tower crane comprises: using an auxiliary lifting device on the luffing jib tower crane to suspend a luffing cylinder needing to be removed, and then removing said luffing cylinder; using the auxiliary lifting device on the luffing jib tower crane to guide said luffing cylinder to pass out through the bottom of a boom; using a hoisting mechanism of the luffing jib tower crane to lower said luffing cylinder to the ground; using the hoisting mechanism of the luffing jib tower crane to lift a luffing cylinder to be installed to the underside of the boom; using the auxiliary lifting device on the luffing jib tower crane to insert the luffing cylinder to be installed into the boom; and using the auxiliary lifting device on the luffing jib tower crane to suspend the luffing cylinder to be installed, and to install said luffing cylinder to the luffing jib tower crane. The luffing jib tower crane allows for direct installation and removal of luffing cylinders, the installation and removal are convenient, time-saving and labor-saving, and no additional lifting device is required, thereby reducing costs.

Description

Jib tower crane variable amplitude oil cylinder replacement method and jib tower crane

[0001] Reference to Related Applications

[0002] This application claims the benefit of Chinese Patent Application 2202411041032.6, filed July 31, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of engineering machinery, in particular to a jib tower crane variable amplitude oil cylinder replacement method and a jib tower crane. BACKGROUND

[0004] The oil cylinder variable amplitude jib tower crane is a new type of jib tower crane, which is driven by a variable amplitude oil cylinder to realize the variable amplitude action of the jib. Compared with the traditional jib tower crane, it has more advantages in space utilization and cost. At present, when the variable amplitude oil cylinder needs to be replaced due to failure or reaching the service life, the tower body needs to be first lowered to a height that can be lifted by other lifting equipment (including truck cranes, crawler cranes, etc.), then the connecting pin shaft between the head part of the jib and the standard section is removed, then the entire head part is lifted and placed on the prepared support on the ground, then the variable amplitude oil cylinder is replaced on the ground with the help of other equipment, and finally the head part is installed back on the tower body. However, this variable amplitude oil cylinder replacement method has the following defects: 1. The process is complicated and requires disassembly and lifting; 2. It occupies a large space and is severely limited by the site; 3. The replacement process is time-consuming, affecting the construction progress; and 4. It needs the assistance of other lifting equipment, which is less economical. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a jib tower crane variable amplitude oil cylinder replacement method that is easy to disassemble and assemble, saves time and effort, and does not require the assistance of other lifting equipment.

[0006] To achieve the above-mentioned purpose, the present application provides a jib tower crane variable amplitude oil cylinder replacement method for replacing the variable amplitude oil cylinder of a jib tower crane, wherein the jib tower crane comprises a tower body, a jib, and a variable amplitude oil cylinder, one end of the variable amplitude oil cylinder is connected to the tower body, and the other end is connected to the jib. The jib tower crane variable amplitude oil cylinder replacement method comprises:

[0007] Using the auxiliary lifting device on the jib tower crane to lift the variable amplitude oil cylinder to be removed, and removing the variable amplitude oil cylinder to be removed;

[0008] Using the auxiliary lifting device on the jib tower crane to pass the variable amplitude oil cylinder to be removed out to the bottom of the jib;

[0009] Using the hoisting mechanism of the jib tower crane to lower the variable amplitude oil cylinder to be removed to the ground;

[0010] Lifting the boom cylinder to be installed to below the lifting boom by using the lifting mechanism of the mobile boom tower crane;

[0011] Passing the boom cylinder to be installed into the lifting boom by using the auxiliary hoisting device on the mobile boom tower crane;

[0012] Hoisting the boom cylinder to be installed by using the auxiliary hoisting device on the mobile boom tower crane, and installing the boom cylinder to be installed to the mobile boom tower crane.

[0013] Optionally, the method further comprises the step before removing the boom cylinder: controlling the lifting boom to an initial state, and removing the locking device for supporting the lifting boom.

[0014] Optionally, the lifting boom comprises an upper chord, a lower chord, a side web, a bottom straight web and a bottom inclined web, the upper chord is provided with a lifting lug for mounting the auxiliary hoisting device, two bottom inclined webs in the shape of an "8" are arranged between two bottom straight webs, thereby forming a triangular hollow at the bottom of the lifting boom to allow the boom cylinder to pass out or pass in; when the boom cylinder passes out of the bottom of the lifting boom or passes into the lifting boom, the boom cylinder passes out of or passes into between the bottom inclined webs in the shape of an "8";

[0015] The method further comprises the step before removing the boom cylinder: removing the walkway at the corresponding position of the bottom inclined web in the shape of an "8".

[0016] Optionally, the auxiliary hoisting device comprises a first auxiliary hoisting device, a second auxiliary hoisting device and a third auxiliary hoisting device; the step of hoisting the boom cylinder to be removed by using the auxiliary hoisting device on the mobile boom tower crane, and removing the boom cylinder to be removed comprises:

[0017] Hoisting the position close to the first end of the boom cylinder by using the first auxiliary hoisting device, and then removing the pin shaft of the first end of the boom cylinder;

[0018] Hoisting the position close to the first end of the boom cylinder by using the first auxiliary hoisting device, hoisting the position close to the second end of the boom cylinder by using the second auxiliary hoisting device, and then removing the pin shaft of the second end of the boom cylinder, the first end and the second end being oppositely arranged;

[0019] Placing the boom cylinder on the winch frame of the lifting boom by using the first auxiliary hoisting device and the second auxiliary hoisting device.

[0020] Optionally, the step of using the auxiliary hoisting device on the mobile boom tower crane to pass the dismounting luffing cylinder out to the bottom of the hoisting boom specifically comprises:

[0021] using the first auxiliary hoisting device and the second auxiliary hoisting device to hoist the first end of the luffing cylinder, and using the third auxiliary hoisting device to hoist the second end of the luffing cylinder, and hoisting the first end of the luffing cylinder to a state of being inclined at a certain angle higher than the second end;

[0022] releasing the first auxiliary hoisting device, and using the second auxiliary hoisting device and the third auxiliary hoisting device to pass the luffing cylinder out to the bottom of the hoisting boom.

[0023] Optionally, the auxiliary hoisting device comprises a first auxiliary hoisting device, a second auxiliary hoisting device and a third auxiliary hoisting device; and the step of using the auxiliary hoisting device on the mobile boom tower crane to pass the luffing cylinder to be installed into the hoisting boom specifically comprises:

[0024] using the second auxiliary hoisting device and the third auxiliary hoisting device to hoist the two ends of the luffing cylinder respectively, and passing the luffing cylinder to be installed into the hoisting boom;

[0025] using the first auxiliary hoisting device, the second auxiliary hoisting device and the third auxiliary hoisting device to hoist the two ends of the luffing cylinder respectively, and placing the luffing cylinder on the drag pulley frame of the hoisting boom.

[0026] Optionally, the step of using the auxiliary hoisting device on the mobile boom tower crane to hoist the luffing cylinder to be installed and installing the luffing cylinder to be installed on the mobile boom tower crane specifically comprises:

[0027] using the first auxiliary hoisting device to hoist the luffing cylinder at a position close to the first end of the luffing cylinder, using the second auxiliary hoisting device to hoist the luffing cylinder at a position close to the second end of the luffing cylinder, and then installing the pin shaft of the second end, the first end and the second end being oppositely arranged;

[0028] releasing the second auxiliary hoisting device, using the first auxiliary hoisting device to hoist the luffing cylinder at a position close to the first end, and then installing the pin shaft of the first end of the luffing cylinder.

[0029] Optionally, the first auxiliary hoisting device, the second auxiliary hoisting device and the third auxiliary hoisting device are arranged in sequence in the direction from the boom root connected to the tower body to the boom tail of the hoisting boom.

[0030] The application further provides a luffing cylinder replacement method for a luffing cylinder of a luffing-jib tower crane.

[0031] Optionally, one end of the bottom inclined web member in the shape of an "8" is connected to one of the lower chord members, and the other end is connected to one of the bottom straight web members; or,

[0032] In the direction from the root of the jib to the tail of the jib, the first auxiliary hoisting device, the second auxiliary hoisting device and the third auxiliary hoisting device are arranged in sequence, the jib is provided with a tug wheel frame on the lower chord member, the tug wheel frame is closer to the root of the jib than the triangular hollow, and the tug wheel frame and the triangular hollow are both located below the first auxiliary hoisting device, the second auxiliary hoisting device and the third auxiliary hoisting device.

[0033] In the luffing cylinder replacement method for a luffing-jib tower crane and the luffing-jib tower crane, the luffing cylinder can be directly disassembled and assembled without disassembling the entire upper part of the luffing-jib tower crane, so that the disassembly and assembly are convenient, time-saving and labor-saving, the replacement of the luffing cylinder can be completed by using the auxiliary hoisting device and the lifting mechanism of the luffing-jib tower crane itself, and no additional hoisting equipment is needed, so that the cost is saved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0035] Fig. 1 is a front view of a part of the jib of the luffing-jib tower crane provided by an embodiment of the application.

[0036] Fig. 2 is a bottom view of a part of the jib of the luffing-jib tower crane shown in Fig. 1.

[0037] Fig. 3 is a flowchart of the luffing cylinder replacement method for a luffing-jib tower crane provided by an embodiment of the application.

[0038] Fig. 4 is a structural diagram of the luffing cylinder replacement method for a luffing-jib tower crane shown in Fig. 3 after the pin shaft at the first end is disassembled in step S11.

[0039] Fig. 5 is a schematic view of the structure after the second end pin is removed in step S11 of the method for replacing the luffing cylinder of the luffing tower crane shown in Fig. 3.

[0040] Fig. 6 is a schematic view of the structure when the luffing cylinder is tilted in step S13 of the method for replacing the luffing cylinder of the luffing tower crane shown in Fig. 3.

[0041] Fig. 7 is a schematic view of the structure when the luffing cylinder is pulled out of the boom in step S11 of the method for replacing the luffing cylinder of the luffing tower crane shown in Fig. 3. DETAILED DESCRIPTION

[0042] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the description of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of the present application.

[0043] In the description of the present application, unless otherwise explicitly specified and limited, the terms "set", "install", "connect" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0044] The terms "first", "second", "third" and the like are only used to distinguish similar attributes or elements, and do not indicate or imply relative importance or a specific order.

[0045] The terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, in addition to containing the listed elements, other elements not explicitly listed can also be contained.

[0046] The embodiment of the present application provides a method for replacing the luffing cylinder of a luffing tower crane, which is used for replacing the luffing cylinder of the luffing tower crane. Please refer to Figs. 1 and 2, the luffing tower crane comprises a tower body, a boom 11 and a luffing cylinder 13 (see Fig. 4), the boom 11 comprises an upper chord 111, a lower chord 113, a side web 114, a bottom straight web 115 and a bottom inclined web 117. The upper chord 111 is provided with lifting lugs 1111, two bottom inclined webs 117 in the shape of "8" are arranged between the two bottom straight webs 115, thereby forming a triangular hollow at the bottom of the boom 11 to allow the luffing cylinder 13 to pass out or pass in. Specifically, one end of the bottom inclined web 117 in the shape of "8" is connected to one of the lower chords 113, and the other end is connected to one of the bottom straight webs 115. One end of the luffing cylinder 13 is connected to the tower body, and the other end is connected to the boom 11.

[0047] Please refer to Fig. 3, the boom tower crane amplitude cylinder replacement method of the embodiment includes the following steps:

[0048] S11, using the auxiliary hoisting device on the boom tower crane to hoist the amplitude cylinder 13 to be removed, and remove the amplitude cylinder 13 to be removed. Specifically, the auxiliary hoisting device on the boom tower crane can be a sling provided on the jib 11, and the lifting lug 1111 on the jib 11 can provide a lifting point for the sling.

[0049] S13, using the auxiliary hoisting device on the boom tower crane to pass the amplitude cylinder 13 to be removed to the bottom of the jib 11. Specifically, the amplitude cylinder 13 is passed from between the bottom inclined web members 117 of the "8" shape to the bottom of the jib 11.

[0050] S15, using the lifting mechanism of the boom tower crane to lower the amplitude cylinder 13 to be removed to the ground. Specifically, the lifting mechanism of the boom tower crane is the lifting mechanism for lifting heavy objects when the boom tower crane is working, and the lifting mechanism of the boom tower crane is relatively long, which can lower the amplitude cylinder 13 from below the jib 11 extending to a high place to the ground.

[0051] S17, using the lifting mechanism of the boom tower crane to lift the amplitude cylinder 13 to be installed to the bottom of the jib 11.

[0052] S19, using the auxiliary hoisting device on the boom tower crane to pass the amplitude cylinder 13 to be installed into the jib 11. Specifically, the amplitude cylinder 13 to be installed is passed from between the bottom inclined web members 117 of the "8" shape to between the inclined web members 114 of the jib 11.

[0053] S21, using the auxiliary hoisting device on the boom tower crane to hoist the amplitude cylinder 13 to be installed, and installing the amplitude cylinder 13 to be installed to the boom tower crane.

[0054] In the boom tower crane amplitude cylinder replacement method of the embodiment, the amplitude cylinder can be directly disassembled and assembled without disassembling the entire upper part of the boom tower crane, so it is convenient to disassemble and assemble, saves time and effort, and the replacement of the amplitude cylinder can be completed by using the auxiliary hoisting device and the lifting mechanism of the boom tower crane itself, without the need for additional hoisting equipment, thereby saving costs.

[0055] In the embodiment, the boom tower crane amplitude cylinder replacement method further includes the step before S11:

[0056] S10, please refer to Figure 4, control the boom 11 to the initial state, and remove the locking device for supporting the boom 11. Specifically, the initial state of the boom 11 generally refers to the state of the boom 11 in the horizontal position, which is also the lowest position of the boom 11 (the boom 11 cannot continue to rotate downward). When the boom 11 is in the initial state, even if the locking device is removed, the boom 11 can remain in the original state without falling.

[0057] Specifically, step S10 further includes removing the walkway corresponding to the position of the "eight" shaped bottom inclined web 117. In this way, space is provided for the variable amplitude oil cylinder 13 to pass out of or into the boom 11.

[0058] In this embodiment, the auxiliary lifting device includes a first auxiliary lifting device 151, a second auxiliary lifting device 152, and a third auxiliary lifting device 153, and step S11 specifically includes:

[0059] S111, please refer to Figure 4 again, using the first auxiliary lifting device 151 to hoist the position of the variable amplitude oil cylinder 13 close to the first end of the variable amplitude oil cylinder 13, and then remove the pin shaft of the first end of the variable amplitude oil cylinder 13. Specifically, the pin shaft of the cylinder end of the variable amplitude oil cylinder 13 can be removed in step S111. Specifically, the first auxiliary lifting device 151 is used to hoist the position between the middle part and the first end of the cylinder barrel of the variable amplitude oil cylinder 13.

[0060] S113, please refer to Figure 5, using the first auxiliary lifting device 151 to hoist the position of the variable amplitude oil cylinder 13 close to the first end of the variable amplitude oil cylinder 13, using the second auxiliary lifting device 152 to hoist the position of the variable amplitude oil cylinder 13 close to the second end of the variable amplitude oil cylinder 13, and then remove the pin shaft of the second end of the variable amplitude oil cylinder 13 opposite to the first end. Specifically, the pin shaft of the piston end of the variable amplitude oil cylinder 13 can be removed in step S113. The second auxiliary lifting device 152 is used to hoist the position between the middle part and the second end of the cylinder barrel of the variable amplitude oil cylinder 13. It can be understood that the pin shaft of the piston end can also be removed first, and then the pin shaft of the cylinder end is removed, but it is more convenient to operate by removing the pin shaft of the cylinder end first.

[0061] S115, using the first auxiliary lifting device 151 and the second auxiliary lifting device 152 to place the variable amplitude oil cylinder 13 on the tugger frame 119 of the boom 11.

[0062] In this embodiment, step S13 specifically includes:

[0063] S131, please refer to FIG. 6, the first auxiliary hoisting device 151 and the second auxiliary hoisting device 152 are used to hoist the first end of the luffing cylinder 13 (for example, the pin hole of the cylinder end of the luffing cylinder), the third auxiliary hoisting device 153 is used to hoist the second end of the luffing cylinder 13 (for example, the pin hole of the piston end of the luffing cylinder), the first end of the luffing cylinder 13 is hoisted to a state of being inclined at an angle higher than the second end.

[0064] S133, please refer to FIG. 7, the first auxiliary hoisting device 151 is loosened, and the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153 are used to pass the luffing cylinder 13 out of the triangular hollow between the bottom inclined web members 117 of the "eight" shaped.

[0065] Specifically, in the direction from the arm root of the tower body connected to the tower body to the arm tail of the tower body, the first auxiliary hoisting device 151, the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153 are arranged in sequence. Specifically, the tug wheel frame 119 is arranged on the lower chord 113 of the tower body and protrudes towards the inner side of the tower body, and the tug wheel frame 119 is used to carry the luffing cylinder 13 with the two end pins removed or the luffing cylinder 13 to be installed which has been hoisted from the ground. The tug wheel frame 119 is closer to the arm root of the tower body than the triangular hollow between the bottom inclined web members 117 of the "eight" shaped. The first auxiliary hoisting device 151, the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153 are arranged on one side of the upper chord 111, so that the triangular hollow formed by the tug wheel frame 119 and the bottom inclined web members 117 of the "eight" shaped is below the first auxiliary hoisting device 151, the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153.

[0066] In the embodiment, step S19 specifically comprises:

[0067] S191, the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153 are used to hoist the two ends (for example, the pin holes of the luffing cylinder) of the luffing cylinder 13 respectively, so that the luffing cylinder 13 to be installed is passed into the tower body. Specifically, the second auxiliary hoisting device 152 can be hung in the pin hole of the cylinder end of the luffing cylinder 13, and the third auxiliary hoisting device 153 can be hung in the pin hole of the piston end of the luffing cylinder 13.

[0068] S193, the first auxiliary hoisting device 151, the second auxiliary hoisting device 152 and the third auxiliary hoisting device 153 are used to hoist the two ends (for example, the pin holes of the luffing cylinder) of the luffing cylinder 13 respectively, so as to place the luffing cylinder 13 on the tug wheel frame of the tower body. Specifically, the first auxiliary hoisting device 151 and the second auxiliary hoisting device 152 can be hung in the pin hole of the cylinder end of the luffing cylinder 13, and the third auxiliary hoisting device 153 can be hung in the pin hole of the piston end of the luffing cylinder 13.

[0069] In this embodiment, step S21 specifically comprises:

[0070] S211, using the first auxiliary hoisting device 151 to hoist the position of the variable amplitude oil cylinder 13 close to the first end of the variable amplitude oil cylinder 13, using the second auxiliary hoisting device 152 to hoist the position of the variable amplitude oil cylinder 13 close to the second end of the variable amplitude oil cylinder 13, and then installing the pin shaft of the second end of the variable amplitude oil cylinder 13. Specifically, the first auxiliary hoisting device 151 is used to hoist the position between the middle and the first end of the cylinder barrel of the variable amplitude oil cylinder 13, and the second auxiliary hoisting device 152 is used to hoist the position between the middle and the second end of the cylinder barrel of the variable amplitude oil cylinder 13.

[0071] S213, loosening the second auxiliary hoisting device 152, using the first auxiliary hoisting device 151 to hoist the position of the variable amplitude oil cylinder 13 close to the first end of the variable amplitude oil cylinder 13, and then installing the pin shaft of the first end of the variable amplitude oil cylinder 13.

[0072] The application also provides a jib tower crane for replacing the variable amplitude oil cylinder by using the above-mentioned variable amplitude oil cylinder replacement method. The jib tower crane comprises a hoisting arm 11 and a variable amplitude oil cylinder 13. The hoisting arm 11 comprises an upper chord 111, a lower chord 113, a side web 114, a bottom straight web 115 and a bottom inclined web 117. The upper chord 111 is provided with a lifting lug 1111, and the lifting lug 1111 is provided with an auxiliary hoisting device. Two bottom inclined webs 117 in the shape of an "eight" are arranged between the two bottom straight webs 115, so as to form a triangular hollow at the bottom of the hoisting arm 11 to allow the variable amplitude oil cylinder 13 to pass out or pass in. One end of the variable amplitude oil cylinder 13 is connected to the tower body, and the other end is connected to the hoisting arm 11.

[0073] In this embodiment, one end of the bottom inclined web 117 in the shape of an "eight" is connected to one of the lower chords 113, and the other end is connected to one of the bottom straight webs 115.

[0074] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or replacements within the technical range disclosed in the application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. A method for replacing a luffing cylinder of a luffing tower crane, the luffing tower crane comprising a tower body, a jib (11) and a luffing cylinder (13), one end of the luffing cylinder (13) being connected to the tower body and the other end being connected to the jib (11), wherein The method for replacing the luffing cylinder of the tower crane comprises the following steps: The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed; The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed; The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed; The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed; The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed; The luffing cylinder (13) to be removed is hoisted by the auxiliary hoisting device on the tower crane, and the luffing cylinder (13) to be removed is removed.

2. The method of replacing the luffing cylinder of a luffing tower crane according to claim 1, wherein The method for replacing the luffing cylinder of the tower crane further comprises the following step before the luffing cylinder (13) is removed: controlling the jib (11) to an initial state and removing the locking device for supporting the jib (11).

3. The method of replacing the luffing cylinder of a luffing tower crane according to claim 1, wherein The jib (11) comprises an upper chord (111), a lower chord (113), a side web (114), a bottom straight web (115) and a bottom inclined web (117), the upper chord (111) is provided with a lifting lug (1111) for mounting the auxiliary hoisting device, two bottom inclined webs (117) in the shape of an "eight" are arranged between two bottom straight webs (115), thereby forming a triangular hollow at the bottom of the jib (11) to allow the luffing cylinder (13) to pass out or pass in, and the luffing cylinder (13) passes out or passes in between the bottom inclined webs (117) in the shape of an "eight" when the luffing cylinder (13) passes out of the bottom of the jib (11) or passes into the jib (11); The method for replacing the luffing cylinder of the tower crane further comprises the following step before the luffing cylinder (13) is removed: removing the walkway at the corresponding position of the bottom inclined web (117) in the shape of an "eight".

4. The method of replacing the luffing cylinder of a luffing tower crane according to claim 1, wherein The auxiliary hoisting device comprises a first auxiliary hoisting device (151), a second auxiliary hoisting device (152) and a third auxiliary hoisting device (153), and the step of hoisting the luffing cylinder (13) to be removed by the auxiliary hoisting device on the tower crane and removing the luffing cylinder (13) to be removed specifically comprises the following steps: The first end of the luffing cylinder (13) is hoisted by the first auxiliary hoisting device (151), and then the pin shaft of the first end of the luffing cylinder (13) is removed; The first end of the luffing cylinder (13) is hoisted by the first auxiliary hoisting device (151), the second end of the luffing cylinder (13) is hoisted by the second auxiliary hoisting device (152), and then the pin shaft of the second end of the luffing cylinder (13) is removed, the first end and the second end being oppositely arranged; The first auxiliary hoisting device (151) and the second auxiliary hoisting device (152) are used to place the luffing cylinder (13) on the trolley frame of the boom (11).

5. The method of replacing the luffing cylinder of a luffing tower crane according to claim 4, wherein The step of using the auxiliary hoisting device on the mobile boom tower crane to pass out the luffing cylinder (13) to be removed to the bottom of the boom (11) specifically includes: The first end of the luffing cylinder (13) is hoisted to a state of being inclined at a certain angle higher than the second end by using the first auxiliary hoisting device (151) and the second auxiliary hoisting device (152) to jointly hoist the first end of the luffing cylinder (13) and using the third auxiliary hoisting device (153) to hoist the second end of the luffing cylinder (13). The first auxiliary hoisting device (151) is loosened, and the second auxiliary hoisting device (152) and the third auxiliary hoisting device (153) are used to pass out the luffing cylinder (13) to the bottom of the boom (11).

6. The method of replacing the luffing cylinder of a luffing tower crane according to claim 1, wherein The auxiliary hoisting device includes a first auxiliary hoisting device (151), a second auxiliary hoisting device (152), and a third auxiliary hoisting device (153). The step of using the auxiliary hoisting device on the mobile boom tower crane to pass in the luffing cylinder (13) to be installed into the boom (11) specifically includes: The two ends of the luffing cylinder (13) are hoisted by the second auxiliary hoisting device (152) and the third auxiliary hoisting device (153) respectively, so that the luffing cylinder (13) to be installed is passed into the boom (11). The two ends of the luffing cylinder (13) are hoisted by the first auxiliary hoisting device (151), the second auxiliary hoisting device (152), and the third auxiliary hoisting device (153) respectively, so that the luffing cylinder (13) is placed on the trolley frame of the boom (11).

7. The method of replacing the luffing cylinder of a luffing tower crane according to claim 6, wherein The step of using the auxiliary hoisting device on the mobile boom tower crane to hoist the luffing cylinder (13) to be installed and installing the luffing cylinder (13) to be installed on the mobile boom tower crane specifically includes: The first auxiliary hoisting device (151) is used to hoist the position close to the first end of the luffing cylinder (13), the second auxiliary hoisting device (152) is used to hoist the position close to the second end of the luffing cylinder (13), and then the pin shaft of the second end is installed, the first end and the second end are oppositely arranged; The second auxiliary hoisting device (152) is loosened, the first auxiliary hoisting device (151) is used to hoist the position close to the first end of the luffing cylinder (13), and then the pin shaft of the first end of the luffing cylinder (13) is installed.

8. The jib crane luffing cylinder replacement method according to claim 4 or 6, wherein The first auxiliary hoisting device (151), the second auxiliary hoisting device (152), and the third auxiliary hoisting device (153) are arranged in sequence in the direction from the arm root connected with the tower body to the arm tail of the boom (11).

9. A method of replacing a luffing cylinder of a luffing tower crane using the method of replacing a luffing cylinder according to any one of claims 1 to 8, wherein The mobile-jib tower crane comprises a jib (11) and a luffing cylinder (13), the jib (11) comprises an upper chord (111), a lower chord (113), a side web (114), a bottom straight web (115) and a bottom inclined web (117), the upper chord (111) is provided with an ear (1111), and an auxiliary hoisting device is installed on the ear (1111), two bottom inclined webs (117) in the shape of an "8" are arranged between two bottom straight webs (115), thereby forming a triangular hollow at the bottom of the jib (11), and one end of the luffing cylinder (13) is connected to the tower body and the other end is connected to the jib (11).

10. The swing boom tower crane of claim 9, wherein, One end of the bottom inclined web (117) in the shape of an "8" is connected to one of the lower chords (113), and the other end is connected to one of the bottom straight webs (115); or, In the direction from the root of the jib (11) connected to the tower body to the tail of the jib, a first auxiliary hoisting device (151), a second auxiliary hoisting device (152) and a third auxiliary hoisting device (153) are arranged in sequence, the lower chord (113) of the jib (11) is provided with a tug wheel frame (119), the tug wheel frame (119) is closer to the root of the jib (11) than the triangular hollow, and the tug wheel frame (119) and the triangular hollow are both located below the first auxiliary hoisting device (151), the second auxiliary hoisting device (152) and the third auxiliary hoisting device (153).

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