Tower crane and cross base transport method

Abstract

This invention provides a transportation method for tower cranes and cross bases that enables a reduction in construction time. [Solution] The tower crane 1 comprises a crane body, a mast extending vertically on which the crane body is mounted, a base frame 110 that supports the lower end of the mast, and a cross base 100 having four outriggers 120, one end of which is rotatably engaged with the base frame 110 and the other end of which extends horizontally.

Description

Technical Field

[0001] The present invention relates to a method for transporting a tower crane and a cross base.

Background Art

[0002] In the case of constructing high-rise buildings or high structures, tower cranes are used because mobile cranes cannot handle these heights. In recent years, wind turbines used in wind power generation have also been made taller and larger in order to increase power generation efficiency. Therefore, even when installing wind turbines, self-standing tower cranes capable of lifting heavy weights are being used.

[0003] In the case of wind power generation, multiple wind turbines are installed at a power plant at predetermined intervals. In the construction process of building one wind turbine, the assembly of the tower crane, the use of the tower crane during the construction of the wind turbine, and the disassembly of the tower crane after the completion of the construction of the wind turbine are carried out. Furthermore, after transporting to the construction site of the next wind turbine, it is necessary to repeat the same construction process.

[0004] Even within one power plant, for example, when constructing dozens of wind turbines, the time required for each of the assembly, disassembly, and transportation of the tower crane has a significant impact on the overall construction period.

[0005] The disassembled members of the tower crane are transported mounted on a multi-axle traveling vehicle. At this time, the width of the mounted members needs to be within the limit of the width of the passage of the multi-axle traveling vehicle.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In a tower crane, the cross base of the tower crane mounts the crane body and the mast that supports it. To prevent the tower crane from tipping over, the cross base is equipped with four outriggers that extend horizontally from the central base frame, for example, in different directions.

[0008] Figure 9 is a conceptual diagram illustrating the state of a tower crane cross base 10 when it is mounted on a multi-axle traveling carriage 20 in a conventional example of transport.

[0009] With respect to the cross base 10, it is usually difficult to fit the integrated assembly within the width limitations of the passage for the multi-axle traveling chassis 20. Therefore, the following procedure is followed.

[0010] First, as shown in Figure 9, the cross base 10, which consists of a base frame 11 (shown by a solid line) with a mast support hole 11a in the center and four outriggers 12 (shown by a dashed line), stands upright on the counter base 13. Next, the multi-axle trolley 20 moves in from below the cross base 10. Then, with the connection between the outriggers 12 and the counter base 13 released, the platform of the multi-axle trolley 20 rises, lifting the cross base 10 from below. Height-adjusting spacers are inserted into the gap formed between the outriggers 12 and the counter base 13. After this, the base frame and outriggers are separated. As a result, the base frame 11 is mounted on the multi-axle trolley 20 by itself. The base frame 11 and outriggers 12 are transported separately to their next destinations, and after their arrival, the base frame 11 and outriggers 12 are reassembled on the multi-axle trolley 20. Finally, the multi-axle trolley 20 moves outwards, and the cross base 10 becomes self-supporting.

[0011] Thus, the cross base 10 had to be disassembled into the base frame 11 and outriggers 12, transported separately, and then reassembled at the site of use. This resulted in increased workload and construction time.

[0012] The problem to be solved by this invention is to provide a method for transporting tower cranes and cross bases that enables a reduction in construction time. [Means for solving the problem]

[0013] To achieve the above-mentioned objectives, the tower crane according to the present invention is characterized by comprising a crane body, a mast extending vertically on which the crane body is mounted, a base frame supporting the lower end of the mast, and a cross base having four outriggers, one end of which is rotatably engaged with the base frame and the other end of which extends horizontally in different directions. [Effects of the Invention]

[0014] The present invention provides a method for transporting tower cranes and cross bases that enables a reduction in construction time. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view showing the configuration of a tower crane according to an embodiment. [Figure 2] This is a plan view showing the configuration of the cross base of a tower crane according to an embodiment. [Figure 3] This is a vertical cross-sectional view showing the configuration of the cross base of a tower crane according to an embodiment. [Figure 4] This is a plan view showing the state after the outriggers of the cross base of the tower crane according to this embodiment have been rotated. [Figure 5] This is a conceptual front view illustrating the conditions for the state of the tower crane after it has been mounted on a cross-base multi-axle traveling carriage according to the embodiment. [Figure 6] This is a flowchart showing the construction procedure for a tower crane, including the procedure for a cross-base transport method according to the embodiment. [Figure 7] This is a conceptual diagram illustrating the state when a multi-axle traveling carriage accesses the cross base of a tower crane in the procedure of a cross base transport method according to an embodiment. [Figure 8] It is a conceptual explanatory diagram showing the state after mounting a tower crane on a cross-base multi-axle carriage in the procedure of the cross-base transport method according to the embodiment. [Figure 9] It is a conceptual explanatory diagram showing the state at the time of mounting on a multi-axle carriage in a conventional example of cross-base transport of a tower crane.

Mode for Carrying out the Invention

[0016] Hereinafter, a tower crane and a cross-base transport method according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and overlapping descriptions are omitted.

[0017] FIG. 1 is a side view showing the configuration of a tower crane 1 according to the embodiment. FIG. 1 shows the state in which the tower crane 1 is assembled.

[0018] The tower crane 1 has a crane body 6, a mast 5, and a cross base 100.

[0019] The crane body 6 is a part having a turning and lifting function for an object to be handled, and has a crane upper part 2 and a jib 3. A roller is provided at the tip of the jib 3 for guiding a wire for suspending a hook for lifting weights. The crane upper part 2 performs operations such as changing the depression angle of the jib 3, turning, and winding up the wire.

[0020] The mast 5 mounts the crane body 6 on its upper part and supports the crane body 6.

[0021] The lifting frame 4 is provided when mast climbing is required. When mast climbing is not required, the equipment is unnecessary.

[0022] The cross base 100 connects to the lower part of the vertically extending mast 5 and supports the mast 5 and the crane body 6. The cross base 100 is mounted on a plate-shaped counter base 8 placed on the ground. The mast 5, crane body 6, etc., which are mounted on the cross base 100 and bear the load of the cross base 100, are collectively referred to as the superstructure 7. The details of the cross base 100 will be explained below with reference to Figures 2 to 4.

[0023] Figure 2 is a plan view showing the configuration of the cross base 100 of the tower crane 1 according to the embodiment. Figure 3 is a vertical cross-sectional view showing the configuration of the cross base 100 of the tower crane 1 according to the embodiment, specifically a cross-sectional view taken along the line AA in Figure 2. Figure 4 is a plan view showing the state after the outrigger 120 of the cross base 100 of the tower crane 1 according to the embodiment has been rotated.

[0024] The cross base 100 has a base frame 110 and four outriggers 120. Each of the four outriggers 120 has an end that engages with the base frame 110 at an engagement portion 131. The outriggers 120 are configured to be rotatable horizontally, with the engagement portion 131 acting as a pivot point. In other words, as shown in Figure 3, the outriggers 120 can rotate, for example, clockwise or counterclockwise, with the engagement portion 131 as the pivot point.

[0025] In the following explanation, for the sake of clarity, the four outrigger bodies 121 may be distinguished and referred to as outrigger bodies 121a, 121b, 121c, and 121d as needed. In this case, outrigger bodies 121a and 121b will be treated as one pair, and outrigger bodies 121c and 121d will be treated as another pair.

[0026] The base frame 110 is the part that directly supports the weight of the mast 5 and the crane body 6. Viewed from above, a mast support hole 112 is formed in the center of the base frame 110 to accommodate the lower end of the mast 5. As shown in Figure 2, the base frame 110 has, for example, a roughly rectangular shape when viewed from above. The base frame 110 also has, for example, four convex portions 111 that project outward horizontally at its four corners. Each of these convex portions 111 has an engagement portion 131 (Figure 3) that engages with the outrigger 120.

[0027] More specifically, as shown in Figure 3, the convex portion 111 of the base frame 110 has an engaging portion 131, which consists of an upper engaging portion 113a and a lower engaging portion 113b. Between the upper engaging portion 113a and the lower engaging portion 113b, there is a concave space 113v into which the engaging portion 122 of the outrigger body 121, which will be described later, is fitted.

[0028] The outrigger 120 has a longitudinally extending outrigger body 121, four lifting jacks 123, and four telescopic operating parts 125.

[0029] As shown in Figure 4, an engaging projection 122 is formed at one end of the outrigger body 121 in the longitudinal direction, serving as an engaging portion 131 with the base frame 110. The engaging projection 122 is fitted into the concave space 113v of the base frame 110.

[0030] The upper engagement projection 113a and lower engagement projection 113b of the base frame 110, and the engagement projection 122 of the outrigger body 121, are formed with upper engagement holes 113c, lower engagement hole 113d, and engagement hole 122a, respectively, so that they are coaxial when the base frame 110 and the outrigger body 121 are engaged.

[0031] In each engagement portion 131, a pivot shaft portion 113s is inserted so as to pass through the upper engagement hole 113c and lower engagement hole 113d of the base frame 110, and the engagement hole 122a of the outrigger body 121. The pivot shaft portion 113s is made of, for example, a cylindrical member.

[0032] The telescopic operating unit 125 moves the four outrigger bodies 121 from the open state shown in Figure 2 to the closed state shown in Figure 4, and from the closed state shown in Figure 4 to the open state shown in Figure 2. In other words, it opens and closes each pair of outrigger bodies 121. Here, the open state refers to the state in which the four outrigger bodies 121 extend in different directions. The open state also refers to the state in which each pair of outrigger bodies 121 are parallel to each other. Here, the pair of outrigger bodies 121 are the pair of outrigger bodies 121a and 121b, and the pair of outrigger bodies 121c and 121d, as shown in Figures 2 and 4. Moving the outrigger bodies 121 to the open state is referred to as opening the outrigger bodies 121, and moving the outrigger bodies 121 to the closed state is referred to as closing the outrigger bodies 121.

[0033] To open and close the outrigger bodies 121, the telescopic operating parts 125 are retractable and, for example, as shown in Figure 2, are provided to connect each outrigger body 121 to the base frame 110. Specifically, as shown in Figure 2, for one pair, they are provided on the opposing surfaces 121f and 121g of outrigger bodies 121a and 121b, respectively. For the other pair, they are provided on the opposing surfaces 121h and 121j of outrigger bodies 121c and 121d, respectively.

[0034] Each telescopic operating section 125 has a rotating cylinder 125a and cylinder joints 125b and 125c. The cylinder joint 125b is provided on the side of the outrigger body 121. For example, for the outrigger body 121a, the cylinder joint 125b is provided on the opposing surface 121f of the outrigger body 121a. Correspondingly, the cylinder joint 125c is provided on the base frame 110. Both ends of the rotating cylinder 125a are connected to the cylinder joints 125b and 125c. The cylinder joints 125b and 125c have a vertical shaft portion, and both ends of the rotating cylinder 125a are configured to rotate horizontally around this shaft portion.

[0035] Therefore, the extension and retraction of this rotating cylinder 125a allows each outrigger body 121 to rotate horizontally around the pivot shaft 113s.

[0036] When the rotating cylinder 125a extends, as shown in Figure 2, the two outrigger bodies 121 of the same pair open to an angle of, for example, 90 degrees when viewed from above. A stopper may be provided to prevent them from opening too far. On the other hand, when the rotating cylinder 125a retracts, the adjacent outrigger bodies 121 rotate until they are in parallel, that is, facing the same direction. In other words, they are in a closed state.

[0037] Here, the telescopic operating part 125 may be hydraulic or mechanical, or any other type as long as it has the function of opening and closing the outrigger body 121. In this embodiment, a rotating cylinder 125a is provided between a cylinder joint 125b provided on the side of the outrigger body 121 and a cylinder joint 125c provided on the base frame 110, but this is not limited to this. For example, a rotating cylinder 125a may be provided between cylinder joints 125b provided on the sides of adjacent outrigger bodies 121. Including other methods, the telescopic operating part 125 may also be provided between opposing surfaces, for example, between opposing surface 121f and opposing surface 121g, or between opposing surface 121h and opposing surface 121j.

[0038] The telescopic operating part 125 may be operated by any coupling or operating method that causes the adjacent outrigger body 121 to rotate and open or close. In this embodiment, the case in which the telescopic operating part 125 is provided is described as an example, as shown in Figure 2, but it is not limited to this. For example, the outrigger body 121 may be opened and closed manually without providing the telescopic operating part 125.

[0039] Each of the four lifting jacks 123 is attached to the other end of the longitudinal direction of each outrigger body 121. The lifting jacks 123 extend and retract vertically downward. As a result, the lifting jacks 123 raise and lower the cross base 100 vertically. Here, the lifting jacks 123 may be hydraulic or mechanical, or any other type as long as it has the function of raising and lowering the cross base 100. Furthermore, in this embodiment, as shown in Figure 2, the case in which the outrigger 120 has lifting jacks 123 is used as an example, but it is not limited to this. For example, the outrigger 120 may not have lifting jacks 123, and temporary lifting jacks may be used to raise and lower the cross base 100.

[0040] Figure 5 is a conceptual front view illustrating the conditions for the state of the cross base 100 of the tower crane 1 after it has been mounted on the multi-axle traveling carriage 20 according to this embodiment. Figure 5 shows the relationship between the cross base 100 mounted on the multi-axle traveling carriage 20 and the road 30 on which the multi-axle traveling carriage 20 travels. Figure 5 also shows a cross section perpendicular to the direction in which the multi-axle traveling carriage 20 travels.

[0041] As shown in Figure 5, the road 30 has a road surface 31 on which the multi-axle mobile vehicle 20 travels, and slopes 32 which are the inclined portions on the left and right sides of the road surface 31.

[0042] If the cross base 100 comes into contact with the slope 32, damage to the slope 32, damage to the cross base 100, displacement of the cross base 100 on the multi-axle traveling trolley 20, and even the cross base 100 falling from the multi-axle traveling trolley 20, as well as other unforeseen incidents, can be anticipated. Therefore, while the multi-axle traveling trolley 20 is traveling on the road surface 31, including curves, it is necessary to avoid situations in which the cross base 100 mounted on the multi-axle traveling trolley 20 comes into contact with the slope 32.

[0043] In order to prevent contact with the slope 32, the width wc of the cross base 100 mounted on the multi-axle traveling carriage 20 is set so that the cross base 100 is located within the first permissible space 33 formed by the road surface 31 and the slope 32 below it.

[0044] Here, the width of the road surface 31 and the conditions of the slope 32 are stipulated by laws and regulations such as technical standards. In Japan, for example, the conditions for this first allowable space 33 are stipulated by the Forestry Agency Director-General's notification as part of the Forest Road Regulations, and the Forest Road Technical Standards concerning motor roads as stipulated in Article 4 of the Forest Road Regulations. Therefore, the dimensions of the cross base 100 when mounted on the multi-axle traveling chassis 20 are set to satisfy these conditions.

[0045] Alternatively, as a simpler condition, the width wc of the cross base 100 may be set so that it fits within the second allowable space 34 of width wr formed above the road surface. In other words, the width wc of the cross base 100 will be smaller than the width wr of the road surface.

[0046] Figure 6 is a flowchart showing the construction procedure for tower crane 1, including the procedure for the cross-base transport method according to the embodiment. Figure 6 illustrates an example where, for example, in the case of a wind power plant, after the construction of one wind turbine is completed, it is transported to the planned site for the construction of the next wind turbine.

[0047] The construction procedure for Tower Crane 1 includes steps S10 for dismantling and preparing the tower crane before transport, step S21 for determining whether there is a next installation site, step S22 for transporting it to the storage site, step S30 for transporting it to the next installation site, and step S40 for assembling the tower crane after transport.

[0048] The tower crane dismantling and pre-transport preparation step S10 includes the removal of the cross base superstructure step S11 and the pre-transport preparation step S12 of the cross base. In step S11, the removal of the cross base superstructure, the superstructure 7 of the cross base 100, namely the crane body 6, mast 5, and lifting frame 4, is removed.

[0049] In the pre-transport preparation step S12, first, with the cross base 100 standing independently on the counter base 8, the lifting jacks 123 extend to raise the height of the cross base 100 (step S12a). Specifically, as the four lifting jacks extend, the base frame 110 of the cross base 100 moves upward while maintaining its horizontal position. At this time, the height of the lower surface of the base frame 110 rises to a height with a margin above the height of the upper surface of the multi-axle traveling trolley 20. For example, this margin is ensured so that when the multi-axle traveling trolley 20 accesses the area below the base frame 110, it can sufficiently absorb the vertical movement of the upper surface of the multi-axle traveling trolley 20 due to uneven ground.

[0050] Next, the multi-axle traveling chassis 20 moves into the space below the cross base 100 (step S12b).

[0051] Figure 7 is a conceptual diagram illustrating the state when the multi-axle traveling carriage 20 accesses the cross base 100 of the tower crane 1 in the procedure of the cross base transport method according to the embodiment. In other words, it is a plan view showing the state at the end of step S12b.

[0052] The cross base 100 is mounted on each of the four counter bases 8. With the lifting jacks 123 extended on each counter base 8, the base frame 110 is held at a sufficient height. The multi-axle traveling carriage 20 has moved below the base frame 110.

[0053] Next, the cross base 100 is mounted onto the multi-axle traveling chassis 20 by the lifting jack 123 (step S12c). Specifically, first, the downward protrusion length of the lifting jack 123 decreases. As a result, the height position of the base frame 110 decreases. Finally, the lower surface of the base frame 110 comes into contact with the upper surface of the multi-axle traveling chassis 20. Furthermore, as the height position of the base frame 110 decreases, the weight of the cross base 100 is supported by the multi-axle traveling chassis 20. The lifting jack 123 ultimately reaches its shortest downward protrusion length.

[0054] Furthermore, in order to ensure that the cross base 100 is securely mounted onto the multi-axle traveling bogie 20, a guide or engaging part may be provided between the lower part of the cross base 100 and the upper part of the multi-axle traveling bogie 20. Alternatively, a member may be provided to prevent the cross base 100 from falling after mounting.

[0055] Next, the outriggers 120 are closed and the cross base 100 is fixed to the multi-axle trolley 20 (step S12d). Specifically, first, the telescopic actuation section 125 retracts, and the two pairs of outrigger bodies 121 move to the closed state. Next, the cross base 100 is fixed to the multi-axle trolley 20, for example, by bolts or lever blocks. Depending on the situation, the fixing of the cross base 100 to the multi-axle trolley 20 may be performed when the outrigger bodies 121 are in the open state, or it may be performed sequentially during the transition from the open state to the closed state of the outrigger bodies 121.

[0056] Figure 8 is a conceptual diagram illustrating the state of the cross base 100 of the tower crane 1 after it has been mounted on the multi-axle traveling carriage 20 in the procedure of the cross base transport method according to the embodiment.

[0057] The cross base 100 is mounted on and fixed to the multi-axle traveling carriage 20. Each pair of outrigger bodies 121 of the cross base 100 is in the closed position. The four counter bases 8 shown in Figure 8 will be transported separately to the next installation location, or they may be prepared separately at the next installation location.

[0058] In a cross-section perpendicular to the direction of travel of the multi-axle traveling carriage 20, the cross base 100 mounted on the multi-axle traveling carriage 20 is sized to satisfy the predetermined conditions of the road on which the multi-axle traveling carriage 20 travels, as explained with reference to Figure 5.

[0059] The above describes the procedure for step S10, which is the dismantling and pre-transport preparation step for the tower crane.

[0060] Following step S10, it is determined whether or not there is a suitable installation location (step S21). In other words, it is determined whether or not there is a place where the tower crane 1 should be used. If it is determined that there is no suitable installation location (step S21 NO), the cross base 100 and other components are transported to the storage location (step S22).

[0061] If it is determined that there is another place of use (step S21 YES), the cross base 100 is transported to the place of use (step S30). For example, in the case of a wind power plant, after the construction of one wind turbine is completed, it is transported to the planned site for the construction of the next wind turbine.

[0062] Next, the assembly step S40 of the tower crane after transport is performed. The assembly step S40 of the tower crane after transport includes the installation step S41 of the cross base after transport and the assembly step S42 of the superstructure of the cross base.

[0063] The following describes the detailed procedure for step S41, the installation step of the cross base after transport.

[0064] First, the four counter bases 8 are positioned in their predetermined locations at the following installation site (step S41a). Specifically, with the cross base 100 installed, each of the four counter bases 8 is positioned to receive the load from each of the four lifting jacks 123.

[0065] Next, the multi-axle traveling trolley 20, equipped with the cross base 100, stops at a predetermined position (step S41b). At this time, assuming that the outrigger bodies 121 of the cross base 100 are open, the orientation of the cross base 100 is determined so that each lifting jack 123 is on its respective counter base 8. That is, the state is as shown in Figure 8.

[0066] Next, the outriggers 120 are opened, and the cross base 100 is released from its attachment to the multi-axle traveling chassis 20 (step S41c). In other words, the attachment of the cross base 100 to the multi-axle traveling chassis 20, which was performed in step S12d, is released.

[0067] Next, the height of the cross base 100 is increased by the lifting jack 123 (step S41d). As shown in Figure 7, the cross base 100 separates from the multi-axle traveling trolley 20 and becomes self-supporting.

[0068] Next, the multi-axle traveling chassis 20 moves outward from below the cross base 100 (step S41e).

[0069] Next, the height of the cross base 100 is lowered by the lifting jack 123, and then the cross base 100 is fixed onto the counter base 8 (step S41f). In other words, the cross base 100 is fixed to the counter base 8. As a result, the tower crane 1 is ready for mounting the mast 5, that is, ready for assembly.

[0070] Following the installation step S41 of the transported cross base, the superstructure 7 of the installed cross base 100 is assembled (step S42).

[0071] As described above, the tower crane 1 according to this embodiment allows the cross base 100 to be transported as a single unit without having to disassemble it into, for example, the base frame 110 and the outriggers 120, by making the outrigger body 121 of the cross base 100 openable and closable. As a result, the workload and working time in pre-transport preparation and post-transport assembly can be reduced.

[0072] Furthermore, the cross base 100 has an extendable mechanism 125, which allows for the safe opening and closing of the outrigger body 121. Additionally, the presence of a lifting jack 123 allows for the safe raising and lowering of the cross base 100. This further reduces the workload and shortens working time.

[0073] According to the embodiments described above, a method for transporting tower cranes and cross bases that enables a reduction in construction time can be provided.

[0074] [Other embodiments] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. Furthermore, the features of each embodiment may be combined. Moreover, the embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0075] 1...Tower crane, 2...Crane upper section, 3...Jib, 4...Lifting frame, 5...Mast, 6...Crane body, 7...Superstructure, 8...Counter base, 10...Cross base according to conventional example, 11...Base frame, 11a...Mast support hole, 12...Legs, 13...Counter base, 20...Multi-axis traveling trolley, 30...Road, 31...Road surface, 32...Slope, 33...First allowable space, 34...Second allowable space, 100...Cross base, 110...Base frame, 111...Convex part, 112...Mast support hole, 11 3a... Upper projection for engagement, 113b... Lower projection for engagement, 113c... Upper engagement hole, 113d... Lower engagement hole, 113s... Rotating shaft, 113v... Concave space, 120... Outrigger, 121, 121a, 121b, 121c, 121d... Outrigger body, 121f, 121g, 121h, 121j... Opposing surfaces, 122... Engaging projection, 122a... Engagement hole, 123... Lifting jack, 125... Telescopic operating part, 125a... Rotating cylinder, 125b, 125c... Cylinder joint, 131... Engagement part

Claims

1. The crane body and The crane body is mounted on a mast that extends vertically, A base frame supporting the lower end of the mast, and a cross base having four outriggers, one end of which is rotatably engaged with the base frame and the other end of which extends horizontally, A tower crane characterized by having the following features.

2. The tower crane according to claim 1, characterized in that the cross base has an extendable mechanism that can transition from an open state in which the four outriggers are open to each other to a closed state in which two of the four outriggers are parallel to each other.

3. The tower crane according to claim 2, characterized in that the telescopic operating part is a hydraulic cylinder.

4. The tower crane according to claim 1, characterized in that each of the four outriggers has a vertically extendable jack at the other end.

5. The tower crane according to claim 1, characterized in that, when the cross base is mounted on the multi-axle traveling carriage in a closed state with two pairs of the four outriggers parallel to each other, the left-right width of the cross base as viewed from the direction of travel of the multi-axle traveling carriage satisfies predetermined conditions of the road on which the multi-axle traveling carriage travels.

6. A method for transporting the cross base of a tower crane, comprising a crane body, a mast extending vertically on which the crane body is mounted, a base frame supporting the lower end of the mast, and a cross base having four outriggers, one end of which is rotatably engaged with the base frame and the other end of which extends horizontally, the method for transporting the cross base of a tower crane, The aforementioned cross-base transport is The first step is to raise the height position of the cross base with the four outriggers of the cross base in an open position, with the outriggers of the cross base open to each other. A second step involves moving the multi-axle traveling trolley into the space below the cross base, A third step involves lowering the height position of the cross base and mounting it on the multi-axle traveling carriage, A fourth step is to fix the cross base on the multi-axle traveling trolley by setting the cross base in a closed state on the multi-axle traveling trolley with two pairs of the four outriggers parallel to each other, A pre-transport preparation step having, Following the aforementioned pre-transportation preparation step, a transport step is performed to transport the cross base to the installation location of the cross base, At the aforementioned installation location, there is an installation step for installing the cross base, A cross-base transportation method characterized by having the following features.

7. The cross base has an extendable / retractable mechanism that can move the outrigger from the open state to the closed state, The method for transporting a cross base according to claim 6, characterized in that the telescopic operating part is used to transition the outrigger to the closed state in the fourth step.

8. Each of the four outriggers is provided with a vertically extendable jack at its other end. The method for transporting a cross base according to claim 6, characterized in that the jack is used to raise the height position of the cross base in the first step and to lower the height position of the cross base in the third step.

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