JP7253909B2 - Tower crane floor climbing method - Google Patents

Description

The present invention relates to a floor climbing construction method for tower cranes.

In general, a tower crane such as a climbing crane is used during construction or demolition of a building such as a building.

FIG. 12 is a schematic diagram showing an example of a conventional tower crane. A tower crane 1 has an elevating unit 3 that can ascend and descend along the mast 2 on top of a mast 2 that can be successively extended upward with mast blocks 2a. A jib 5 is mounted on the slewing body 4 so that it can be raised and lowered. A counter frame 6 extending rearward is provided integrally with the slewing body 4. , a hoisting device 9 for hoisting and lowering a wire rope 8 for suspending a load hook 7, and a hoisting device 11 for hoisting and lowering a wire rope 10 for hoisting a jib 5. have.

The bottom of the mast 2 is fixed to a frame 13 provided on a foundation 12 by fastening members (not shown) such as bolts and nuts.

On the other hand, in recent years, a seismic isolation structure 15 equipped with a seismic isolation device 14 has been increasing as the building.

For example, when constructing the seismic isolation structure 15, the mast blocks 2a are successively added to the tower crane 1 up to a preset maximum self-supporting height, as shown in FIG. 12(a). Then, the construction work of the seismic isolation structure 15 proceeds with the mast 2 standing alone.

When the construction work of the seismic isolation structure 15 progresses and the maximum self-standing height of the tower crane 1 is exceeded, the mast 2 is connected to the seismic isolation structure 15 by stays 16 as shown in FIG. 12(b). Further work can be continued in this state.

Incidentally, when the seismic isolation structure 15 is dismantled, if the tower crane 1 exceeds the maximum self-standing height, the mast 2 is connected to the seismic isolation structure 15 by stays 16 as shown in FIG. 12(b). The dismantling work proceeds from this state, the mast blocks 2a are removed sequentially from above, and when the tower crane 1 reaches the maximum self-supporting height or less, the stay 16 is removed, and as shown in FIG. 12(a), The dismantling work of the seismic isolation structure 15 proceeds with the mast 2 standing alone.

For example, Japanese Patent Laid-Open Publication No. 2002-300000 discloses a general technical level related to the tower crane 1 as described above.

JP-A-2000-303695

However, when an earthquake occurs and the base isolation device 14 of the base isolation structure 15 works and the mounting location of the stay 16 is largely displaced in the horizontal direction, as shown in FIG. Since the lower portion of the crane, including the crane, is fixedly supported, there is a risk that an excessive moment and horizontal force will act on the mast 2, the frame 13, and the foundation 12. In addition, even in a simple structure not equipped with the seismic isolation device 14, when an earthquake occurs and the structure bends and the mounting location of the stay 16 is displaced in the horizontal direction, the lower part of the crane including the lower end of the mast 2 and the pedestal 13 Since they are fixedly supported, there is a risk that a large moment and horizontal force will act on the mast 2, the pedestal 13, and the foundation 12, as described above.

Incidentally, in order to increase the allowable amount of forced displacement due to bending of the tower crane 1 following the displacement of the seismic isolation structure 15 when an earthquake occurs, for example, the mounting location of the stay 16 to the seismic isolation structure 15 is changed. However, in order to raise the mounting location of the stay 16, it is necessary to increase the self-supporting height of the tower crane 1, and along with this, the strength of the mast 2, the frame 13, and the foundation 12 is increased. However, there is a problem that it has to be increased, leading to an increase in cost. Such a problem also applies to simple structures.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to prevent the application of excessive moment and horizontal force to the mast, frame, and foundation, and to improve stability while reducing costs. To provide a floor-climbing construction method for a tower crane that is

In order to achieve the above object , the present invention provides a tower crane equipped with a mast erected on a platform and used during construction or demolition of a structure,
a stay connecting the mast to the structure;
a connecting portion that is set in the lower part of the crane at a position below the stay and that can be switched between a state in which the lower part of the crane is divided vertically or a state in which it is fixed;
a fastening mechanism that holds the connecting portion in a fixed state;
The fixed state of the connecting part by the fastening mechanism is released, and the lower part of the crane is interposed between the vertically divided crane lower parts, and the crane lower part is rotatable at the connecting part while supporting the horizontal load and the vertical load acting on the crane lower part. and a lower pin support structure with a self-aligning bearing that supports the

The fastening mechanism is
an upper flange portion disposed on the outer peripheral portion of the upper lower end of the vertically divided crane lower portion;
a lower flange portion disposed on the outer peripheral portion of the lower upper end of the lower portion of the vertically divided crane;
an intermediate flange portion that can be freely inserted between the upper flange portion and the lower flange portion;
a fastening member that can be freely fastened by penetrating the intermediate flange portion and the upper and lower flange portions;
has
The intermediate flange portion has a rectangular cross section with horizontal upper and lower surfaces,
The upper flange portion has a lower surface along the upper surface of the intermediate flange portion,
A tower crane floor climbing method in which the lower flange portion has an upper surface along the lower surface of the intermediate flange portion,
When the direction of the beam receiving the outriggers of the frame of the tower crane is different on each floor of the structure, the frame is aligned with the direction of the beam of the floor on which the outrigger is to be fixedly supported, and the fastening mechanism is released. The floor climbing construction method for a tower crane is characterized by including a step of turning upward.

Furthermore, in the lower pin support structure of the tower crane, an upper cross box-shaped beam formed so as to span between the main members at the four corners at the upper lower part of the lower part of the crane, and at the lower upper part of the lower part of the crane A lower cross box-shaped beam formed so as to span between the main members at the four corners,
The self-aligning bearing includes a convex portion attached to either the central portion of the lower surface of the upper cross box-shaped beam or the central portion of the upper surface of the lower cross box-shaped beam, and the central portion of the lower surface of the upper cross box-shaped beam. or a concave portion attached to the other of the central portion of the upper surface of the lower cross box-shaped beam and into which the convex portion is slidably fitted.

According to the tower crane floor climbing construction method of the present invention, the lower pin support structure can prevent excessive moment and horizontal force from acting on the mast, frame, and foundation, and can improve stability while reducing costs. is used, and even if the directions of the beams receiving the outriggers of the tower crane mount are different on each floor of the structure, floor climbing can be performed efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows one Example of this invention, (a) is a figure which shows the self-supporting state by a mast independent, (b) is a figure which shows the state which the mast was connected with the seismic isolation structure by the stay. . FIG. 4 is a perspective view showing a connecting portion of a mast in one embodiment of the present invention; FIG. 4 is a plan view showing a cross box-shaped beam supporting a self-aligning bearing in one embodiment of the present invention; 1 is a side view showing a self-aligning bearing in one embodiment of the present invention; FIG. 1 is a flow chart showing steps during construction in one embodiment of the present invention. 4 is a flow chart showing a dismantling process in one embodiment of the present invention. It is a first operation diagram relating to the floor climbing construction method of the present invention. FIG. 4 is a second operation diagram relating to the floor climbing construction method of the present invention; FIG. 4 is a third operation diagram relating to the floor climbing construction method of the present invention; It is a fourth operation diagram relating to the floor climbing construction method of the present invention. It is a fifth operation diagram relating to the floor climbing construction method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the conventional tower crane, (a) is a figure which shows the self-supporting state by a mast independent, (b) is a figure which shows the state where the mast is connected with the seismic isolation structure by the stay. .

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 11 show an embodiment of the present invention, and in the figures, the same reference numerals as in FIG. 12 represent the same parts.

In the case of this embodiment, a connecting portion 17 is set at the bottom of the mast 2 (a position below the stay 16), which is the lower part of the crane, and the connecting portion 17 is fixed by a fastening mechanism 18 in a state in which the mast 2 is vertically divided. It is possible to switch to the closed state. Instead of setting the connecting portion 17 at the bottom of the mast 2 , the connecting portion 17 may be set at the pedestal 13 so that the pedestal 13 may be divided vertically or fixed by the fastening mechanism 18 .

As shown in FIG. 2, the fastening mechanism 18 that holds the connecting portion 17 fixed includes an upper flange portion 18a, a lower flange portion 18b, an intermediate flange portion 18d, and a fastening member 18e. The upper flange portion 18a is arranged on the outer peripheral portion of the lower end of the upper mast 2b of the vertically divided mast 2 so as to be integrated with the main member 2d at the four corners. The lower flange portion 18b is arranged on the outer peripheral portion of the upper end of the lower mast 2c of the vertically divided mast 2 so as to be integrated with the main member 2e at the four corners. The intermediate flange portion 18d has a rectangular cross section with horizontal upper and lower surfaces, and is a member that can be freely inserted between the upper flange portion 18a and the lower flange portion 18b. 18a has a lower surface along the upper surface of the intermediate flange portion 18d, and the lower flange portion 18b has an upper surface along the lower surface of the intermediate flange portion 18d. The fastening member 18e is a member such as a bolt or nut that can be freely fastened by passing through the intermediate flange portion 18d and the upper and lower flange portions 18a and 18b.

A self-aligning bearing 19 capable of applying a radial load and an axial load at the same time is interposed between the masts 2 separated vertically by releasing the fixed state of the connecting portion 17 by the fastening mechanism 18 . An upper cross box beam 20 is attached to the lower part of the upper mast 2b so as to bridge between the main members 2d at the four corners. Similarly, the upper mast 2c has the main members 2e at the four corners. A lower cross box-shaped beam 21 is attached so as to span between them. As shown in FIGS. 3 and 4, the self-aligning bearing 19 includes a convex portion 19a attached to the center of the lower surface of the upper cross box-shaped beam 20 and a center portion of the upper surface of the lower cross box-shaped beam 21. and a concave surface portion 19b into which the convex surface portion 19a is slidably fitted. It's like The self-aligning bearing 19 may be configured such that the concave portion 19b is attached to the center of the lower surface of the upper cross box-shaped beam 20, and the convex portion 19a is attached to the center of the upper surface of the lower cross box-shaped beam 21. . Further, the self-aligning bearing 19 may be of any type as long as it can simultaneously apply a radial load and an axial load.

Incidentally, in this embodiment, when constructing the seismic isolation structure 15, as shown in FIG. 5, a self-sustaining step SC1, a connecting step SC2, a dividing step SC3, and a pin supporting step SC4 are performed.

In the self-sustaining step SC1, the connecting part 17 set at the bottom of the mast 2 (a position below the stay 16) is fixed to make the mast 2 self-sustaining, and mast blocks 2a are successively added to make the mast 2 stand alone in a self-sustaining state. This is the process of advancing the construction work of the seismic structure 15 (see FIG. 1(a)).

In the connection step SC2, the mast 2 is attached to the base isolation structure 15 by the stay 16 when the construction work of the base isolation structure 15 progresses in the self-supporting step SC1 and the maximum self-supporting height of the tower crane 1 is exceeded. (See FIG. 1(b)).

The dividing step SC3 is a step of vertically dividing the mast 2 at the connecting portion 17 set at a lower position than the stay 16 connected in the connecting step SC2.

In the pin supporting step SC4, a self-aligning bearing 19 interposed between the masts 2 vertically divided in the dividing step SC3 supports the horizontal load and the vertical load acting on the mast 2 while supporting the mast 2. is rotatably supported at the connecting portion 17, and the construction work of the seismic isolation structure 15 is carried out in this state.

On the other hand, in this embodiment, when dismantling the seismic isolation structure 15, as shown in FIG. 6, a connecting step SD1, a dividing step SD2, a pin supporting step SD3, and a self-supporting step SD4 are performed.

In the connection step SD1, in the case of the seismic isolation structure 15 exceeding the maximum self-supporting height of the tower crane 1, the mast 2 is connected to the seismic isolation structure 15 with stays 16 as shown in FIG. 1(b). It is a process to advance dismantling work from the state.

The dividing step SD2 is a step of vertically dividing the mast 2 at the connecting portion 17 set at a lower position than the stay 16 connected in the connecting step SD1.

In the pin supporting step SD3, a self-aligning bearing 19 interposed between the masts 2 vertically divided in the dividing step SD2 supports the horizontal load and the vertical load acting on the mast 2 while supporting the mast 2. is rotatably supported at the connecting portion 17, and the seismic isolation structure 15 is dismantled in this state.

In the self-supporting step SD4, the mast 2 is rotatably supported at the connecting portion 17 in the pin supporting step SD3, and then the seismic isolation structure 15 is dismantled, and the mast blocks 2a are sequentially removed from above. When the tower crane 1 falls below the maximum self-supporting height, the stay 16 is removed, and the connecting part 17 set at the bottom of the mast 2 (position below the stay 16) is fixed to make the mast 2 self-supporting. Then, the dismantling work of the seismic isolation structure 15 is advanced while the mast 2 stands alone (see FIG. 1(a)).

Next, how to use the tower crane 1 detailed above will be described below .

When constructing the seismic isolation structure 15, first, the connection part 17 set at the bottom of the mast 2 (position below the stay 16) is fixed by the fastening mechanism 18 to make the mast 2 self-supporting, and the mast blocks 2a are successively added to the mast. The construction work of the seismic isolation structure 15 is advanced in a self-supporting state by itself (see FIG. 1(a)). Here, as shown in FIGS. 2 and 4, the intermediate flange portion 18d of the fastening mechanism 18 is fitted between the upper flange portion 18a and the lower flange portion 18b, and the fastening member 18e is inserted between the intermediate flange portion 18d and the lower flange portion 18b. When the upper flange portion 18 a and the lower flange portion 18 b are penetrated and fastened, the connecting portion 17 is fixed by the fastening mechanism 18 . Incidentally, this step is the self-sustaining step SC1 in FIG.

When the construction work of the seismic isolation structure 15 progresses and the maximum self-standing height of the tower crane 1 is exceeded, the mast 2 is connected to the seismic isolation structure 15 by stays 16 (see FIG. 1(b)). In addition, in FIG. 5, this step becomes a connection step SC2 following the self-sustaining step SC1.

When the mast 2 is connected to the seismic isolation structure 15 by the stay 16 , the mast 2 is vertically divided at the connecting portion 17 . Here, the fastening of the fastening member 18e is released, and the intermediate flange portion 18d is moved from between the upper flange portion 18a and the lower flange portion 18b to the inner or outer peripheral side of the mast 2 as shown by the phantom lines in FIG. When the connector 17 is pulled out to the side, the connection portion 17 is released from the fastening mechanism 18 . Incidentally, this step becomes a dividing step SC3 following the connecting step SC2 in FIG.

Since a self-aligning bearing 19 is interposed between the vertically divided masts 2, the mast 2 rotates at the connecting portion 17 while the horizontal load and vertical load acting on the mast 2 are supported. It is freely supported, and the construction work of the seismic isolation structure 15 is performed in this state. Here, when an earthquake occurs, the mast 2 rotates at the connecting portion 17 by sliding the convex portion 19a of the self-aligning bearing 19 against the concave portion 19b. This step is the pin supporting step SC4 following the cutting step SC3 in FIG.

On the other hand, when dismantling the seismic isolation structure 15 that exceeds the maximum self-supporting height of the tower crane 1, first, dismantling work proceeds from the state where the mast 2 is connected to the seismic isolation structure 15 by the stay 16 (Fig. 1). (b)). Incidentally, this step becomes the connection step SD1 in FIG.

At this time, the mast 2 is vertically divided at the connecting portion 17 set below the stay 16 . Here, the fastening by the fastening member 18e of the fastening mechanism 18 is released, and as shown by the phantom lines in FIG. The connecting portion 17 is in a state in which the fixing by the fastening mechanism 18 is released. Incidentally, this step becomes a dividing step SD2 subsequent to the connecting step SD1 in FIG.

Since a self-aligning bearing 19 is interposed between the vertically divided masts 2, the mast 2 rotates at the connecting portion 17 while the horizontal load and vertical load acting on the mast 2 are supported. It is freely supported, and the dismantling work of the seismic isolation structure 15 is performed in this state. Note that this step becomes a pin supporting step SD3 following the dividing step SD2 in FIG.

From the state in which the mast 2 is rotatably supported by the connecting portion 17, the seismic isolation structure 15 is dismantled, and the mast blocks 2a are removed sequentially from above, until the maximum self-supporting height of the tower crane 1 is reached. When the height is lowered, the stay 16 is removed, and the connecting portion 17 set at the bottom of the mast 2 (position below the stay 16) is fixed, and the seismic isolation structure 15 is dismantled while the mast 2 stands alone. Work proceeds (see FIG. 1(a)). Here, as shown in FIGS. 2 and 4, the intermediate flange portion 18d of the fastening mechanism 18 is fitted between the upper flange portion 18a and the lower flange portion 18b, and the fastening member 18e is inserted between the intermediate flange portion 18d and the lower flange portion 18b. When the upper flange portion 18 a and the lower flange portion 18 b are penetrated and fastened, the connecting portion 17 is fixed by the fastening mechanism 18 . In addition, in FIG. 6, this step becomes an independent step SD4 following the pin supporting step SD3.

As a result, in this embodiment, even if the base isolation device 14 of the base isolation structure 15 is activated and the mounting location of the stay 16 is largely displaced in the horizontal direction when an earthquake occurs, the lower part of the mast 2 of the tower crane 1 cannot be fixedly supported. Therefore, the mast 2, the frame 13, and the foundation 12 are subjected to excessive moment and horizontal force regardless of whether the seismic isolation structure 15 is constructed or demolished. disappears.

Along with this, for example, the mounting position of the stay 16 with respect to the seismic isolation structure 15 is raised, and the permissible amount of forced displacement is increased by bending the tower crane 1 following the displacement of the seismic isolation structure 15 when an earthquake occurs. Since there is no need to increase the size, the stand-alone height of the tower crane 1 does not need to be increased, and the strength of the mast 2, the frame 13, and the foundation 12 can be kept low, and cost increase can be avoided.

In this way, it is possible to prevent excessive moment and horizontal force from acting on the mast 2, the frame 13, and the foundation 12, and it is possible to improve stability while reducing costs.

In the case of the present embodiment, the fastening mechanism 18 includes an upper flange portion 18a disposed on the outer periphery of the lower end of the vertically divided crane lower portion (upper mast 2b of the mast 2), and the vertically divided upper flange portion 18a. A lower flange portion 18b disposed on the outer peripheral portion of the upper end of the lower part of the crane (the lower mast 2c of the mast 2), and the upper flange portion 18a and the lower flange portion 18b. It has an intermediate flange portion 18d and a fastening member 18e that can be freely fastened by penetrating the intermediate flange portion 18d, the upper flange portion 18a and the lower flange portion 18b. With this configuration, the intermediate flange portion 18d of the fastening mechanism 18 is fitted between the upper flange portion 18a and the lower flange portion 18b, and the fastening member 18e is connected to the intermediate flange portion 18d, the upper flange portion 18a, and the lower flange portion 18a. By penetrating the flange portion 18b and fastening, the connecting portion 17 can be stably held in a fixed state.

Also, an upper cross box-shaped beam 20 formed so as to bridge between the main members 2d at the four corners at the lower part of the upper part of the lower part of the crane (upper mast 2b), and the lower part of the lower part of the crane (lower mast 2c). A lower cross box-shaped beam 21 formed so as to bridge between the main members 2e at the four corners is provided on the upper part, and the self-aligning bearing 19 is located at the center or lower side of the lower surface of the upper cross box-shaped beam 20. A convex surface portion 19a attached to one of the central portions of the upper surface of the cross box beam 21 (the central portion of the lower surface of the upper cross box beam 20 in the example of FIG. 4), and the central portion of the lower surface of the upper cross box beam 20 or a concave surface that is attached to either one of the central portions of the upper surface of the lower cross box-shaped beam 21 (in the example of FIG. 4, the central portion of the upper surface of the lower cross box-shaped beam 21) and into which the convex surface portion 19a is slidably fitted. and a portion 19b. With this configuration, the upper cross box-shaped beam 20 formed so as to span between the main members 2d at the four corners at the lower part of the upper side (upper mast 2b) of the lower part of the crane, and the lower side of the lower part of the crane (lower side) While increasing the rigidity of the lower part of the crane (mast 2) with a lower cross box-shaped beam 21 formed so as to span between the main members 2e at the four corners on the upper part of the mast 2c), the upper cross box-shaped beam 20 and the lower By sliding the convex portion 19a of the self-aligning bearing 19 against the concave portion 19b between the side cross box beams 21, the pivoting motion of the connecting portion 17 of the lower part of the crane (mast 2) is stabilized. be able to.

On the other hand, if the tower crane 1 is not used in a self-supporting state and is used only in a state where the mast 2 is connected to the seismic isolation structure 15 by the stay 16, an excessive moment and horizontal force will act on the foundation 12. However, since the foundation 12 that can support only the vertical force is sufficient, the cost for the foundation 12 can be greatly reduced.

Moreover, since the directions of the mount 13 and the mast 2 can be changed steplessly, the climbing direction can also be set steplessly. As a result, the orientation of the jib 5 during climbing can be set steplessly, preventing the jib 5 and the counter frame 6 of the revolving body 4 from protruding outside the construction site or interfering with other adjacent structures. can be avoided, and installation planning of the tower crane 1 can be facilitated.

Furthermore, the lower pin support structure of the tower crane of this embodiment has a beam 15H that receives the outriggers 13a of the frame 13 of the tower crane 1 on the lower and upper layers of the structure 15A during floor climbing as shown in FIGS. It can be effectively used even when the directions of the two are different.

First, as shown in FIG. 7, the outriggers 13a are fixedly supported by the beams 15H of a certain story, and the coupling portion 17 is fixed by the fastening mechanism 18. From this state, the lifting unit 3 is lowered as shown in FIG. A support member 3H projecting from the lift unit 3 is placed on the upper beam 15H of the structure 15A.

Subsequently, the fixed support of the outriggers 13a to the beams 15H is released, and the mast 2 is lifted by the lifting unit 3 as shown in FIG.

After that, the connection portion 17 is released from the fastening mechanism 18, and as shown in FIG.

Next, the outrigger 13a is placed on the upper beam 15H and fixed, and the connecting portion 17 is fixed by the fastening mechanism 18 again.

After the connecting portion 17 is fixed again by the fastening mechanism 18, the lifting unit 3 is lifted along the mast 2 as shown in FIG.

That is, if the connecting portion 17 can be switched between a state in which the lower part of the crane is vertically divided by the fastening mechanism 18 or a state in which it is fixed, the direction of the beam 15H receiving the outriggers 13a of the frame 13 of the tower crane 1 is adjusted to the direction of the structure. Floor climbing can be performed efficiently even if the lower and upper layers of 15A are different by 90° or other angles.

It should be noted that the tower crane floor climbing construction method of the present invention is not limited to the above-described embodiments, and is applicable not only to seismic isolation structures but also to structures having earthquake resistance and vibration damping functions. In addition, it goes without saying that various modifications can be made without departing from the scope of the present invention, such as application to mere structures that do not have seismic isolation, earthquake resistance, or damping functions.

REFERENCE SIGNS LIST 1 tower crane 2 mast 2a mast block 2b upper mast 2c lower mast 2d main member 2e main member 3 lifting unit 3H support member 4 revolving body 5 jib 6 counter frame 7 load hook 8 wire rope 9 hoisting device 10 wire rope 11 Elevating device 12 Foundation 13 Mounting frame 13a Outrigger 14 Seismic isolation device 15 Seismic isolation structure (structure)
15A Structure 15H Beam 16 Stay 17 Connecting portion 18 Fastening mechanism 18a Upper flange portion 18b Lower flange portion 18d Intermediate flange portion 18e Fastening member 19 Self-aligning bearing 19a Convex portion 19b Concave portion 20 Upper cross box beam 21 Lower side cross box beam

Claims (2)

A tower crane equipped with a mast erected on a frame used during construction or demolition of a structure,
a stay connecting the mast to the structure;
a connecting portion that is set in the lower part of the crane at a position below the stay and that can be switched between a state in which the lower part of the crane is vertically divided or a state in which the crane lower part is fixed;
a fastening mechanism that holds the connecting portion in a fixed state;
The fixed state of the connecting part by the fastening mechanism is released, and the crane lower part is interposed between the vertically divided crane lower parts, and the crane lower part is rotatable at the connecting part while supporting the horizontal load and the vertical load acting on the crane lower part. and a lower pin support structure with a self-aligning bearing that supports the
The fastening mechanism is
an upper flange portion disposed on the outer peripheral portion of the upper lower end of the vertically divided crane lower portion;
a lower flange portion disposed on the outer peripheral portion of the lower upper end of the lower portion of the vertically divided crane;
an intermediate flange portion that can be freely inserted between the upper flange portion and the lower flange portion;
a fastening member that can be freely fastened by penetrating the intermediate flange portion and the upper and lower flange portions;
has
The intermediate flange portion has a rectangular cross section with horizontal upper and lower surfaces,
The upper flange portion has a lower surface along the upper surface of the intermediate flange portion,
A tower crane floor climbing method in which the lower flange portion has an upper surface along the lower surface of the intermediate flange portion,
When the direction of the beam receiving the outriggers of the frame of the tower crane is different on each floor of the structure, the frame is aligned with the direction of the beam of the floor on which the outrigger is to be fixedly supported, and the fastening mechanism is released. A floor climbing construction method for a tower crane, comprising a step of swinging upward. The lower pin support structure of the tower crane includes an upper cross box-shaped beam formed so as to span between the main members at the four corners at the lower part of the upper part of the lower part of the crane, and the main members at the four corners at the upper part of the lower part of the lower part of the crane. A lower cross box beam formed to span between materials,
The self-aligning bearing includes a convex portion attached to either the central portion of the lower surface of the upper cross box-shaped beam or the central portion of the upper surface of the lower cross box-shaped beam, and the central portion of the lower surface of the upper cross box-shaped beam. 2. The tower crane according to claim 1, further comprising a concave surface portion attached to the other of the upper surface center portion of the lower cross box-shaped beam and into which the convex surface portion is slidably fitted. floor climbing method.

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